--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/ipipe.h
+++ b/arch/blackfin/include/asm/ipipe.h
@@ -35,9 +35,9 @@
 #include <asm/atomic.h>
 #include <asm/traps.h>
 
-#define IPIPE_ARCH_STRING     "1.8-00"
+#define IPIPE_ARCH_STRING     "1.9-00"
 #define IPIPE_MAJOR_NUMBER    1
-#define IPIPE_MINOR_NUMBER    8
+#define IPIPE_MINOR_NUMBER    9
 #define IPIPE_PATCH_NUMBER    0
 
 #ifdef CONFIG_SMP
@@ -118,35 +118,40 @@ void __ipipe_disable_irqdesc(struct ipipe_domain *ipd,
 
 #define __ipipe_disable_irq(irq)	(irq_desc[irq].chip->mask(irq))
 
-#define __ipipe_lock_root()					\
-	set_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags)
+static inline int __ipipe_check_tickdev(const char *devname)
+{
+	return 1;
+}
 
-#define __ipipe_unlock_root()					\
-	clear_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags)
+static inline void __ipipe_lock_root(void)
+{
+	set_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status));
+}
+
+static inline void __ipipe_unlock_root(void)
+{
+	clear_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status));
+}
 
 void __ipipe_enable_pipeline(void);
 
 #define __ipipe_hook_critical_ipi(ipd) do { } while (0)
 
-#define __ipipe_sync_pipeline(syncmask)					\
-	do {								\
-		struct ipipe_domain *ipd = ipipe_current_domain;	\
-		if (likely(ipd != ipipe_root_domain || !test_bit(IPIPE_ROOTLOCK_FLAG, &ipd->flags))) \
-			__ipipe_sync_stage(syncmask);			\
-	} while (0)
+#define __ipipe_sync_pipeline  ___ipipe_sync_pipeline
+void ___ipipe_sync_pipeline(unsigned long syncmask);
 
 void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs);
 
 int __ipipe_get_irq_priority(unsigned irq);
 
-int __ipipe_get_irqthread_priority(unsigned irq);
-
 void __ipipe_stall_root_raw(void);
 
 void __ipipe_unstall_root_raw(void);
 
 void __ipipe_serial_debug(const char *fmt, ...);
 
+asmlinkage void __ipipe_call_irqtail(unsigned long addr);
+
 DECLARE_PER_CPU(struct pt_regs, __ipipe_tick_regs);
 
 extern unsigned long __ipipe_core_clock;
@@ -162,42 +167,25 @@ static inline unsigned long __ipipe_ffnz(unsigned long ul)
 
 #define __ipipe_run_irqtail()  /* Must be a macro */			\
 	do {								\
-		asmlinkage void __ipipe_call_irqtail(void);		\
 		unsigned long __pending;				\
-		CSYNC();					\
+		CSYNC();						\
 		__pending = bfin_read_IPEND();				\
 		if (__pending & 0x8000) {				\
 			__pending &= ~0x8010;				\
 			if (__pending && (__pending & (__pending - 1)) == 0) \
-				__ipipe_call_irqtail();			\
+				__ipipe_call_irqtail(__ipipe_irq_tail_hook); \
 		}							\
 	} while (0)
 
 #define __ipipe_run_isr(ipd, irq)					\
 	do {								\
 		if (ipd == ipipe_root_domain) {				\
-			/*						\
-			 * Note: the I-pipe implements a threaded interrupt model on \
-			 * this arch for Linux external IRQs. The interrupt handler we \
-			 * call here only wakes up the associated IRQ thread. \
-			 */						\
-			if (ipipe_virtual_irq_p(irq)) {			\
-				/* No irqtail here; virtual interrupts have no effect \
-				   on IPEND so there is no need for processing \
-				   deferral. */				\
-				local_irq_enable_nohead(ipd);		\
+			local_irq_enable_hw();				\
+			if (ipipe_virtual_irq_p(irq))			\
 				ipd->irqs[irq].handler(irq, ipd->irqs[irq].cookie); \
-				local_irq_disable_nohead(ipd);		\
-			} else						\
-				/*					\
-				 * No need to run the irqtail here either; \
-				 * we can't be preempted by hw IRQs, so	\
-				 * non-Linux IRQs cannot stack over the short \
-				 * thread wakeup code. Which in turn means \
-				 * that no irqtail condition could be pending \
-				 * for domains above Linux in the pipeline. \
-				 */					\
+			else						\
 				ipd->irqs[irq].handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs)); \
+			local_irq_disable_hw();				\
 		} else {						\
 			__clear_bit(IPIPE_SYNC_FLAG, &ipipe_cpudom_var(ipd, status)); \
 			local_irq_enable_nohead(ipd);			\
@@ -217,42 +205,24 @@ void ipipe_init_irq_threads(void);
 
 int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc);
 
-#define IS_SYSIRQ(irq)		((irq) > IRQ_CORETMR && (irq) <= SYS_IRQS)
-#define IS_GPIOIRQ(irq)		((irq) >= GPIO_IRQ_BASE && (irq) < NR_IRQS)
-
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+#define IRQ_SYSTMR		IRQ_CORETMR
+#define IRQ_PRIOTMR		IRQ_CORETMR
+#else
 #define IRQ_SYSTMR		IRQ_TIMER0
 #define IRQ_PRIOTMR		CONFIG_IRQ_TIMER0
+#endif
 
-#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
-#define PRIO_GPIODEMUX(irq)	CONFIG_PFA
-#elif defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537)
-#define PRIO_GPIODEMUX(irq)	CONFIG_IRQ_PROG_INTA
-#elif defined(CONFIG_BF52x)
-#define PRIO_GPIODEMUX(irq)	((irq) == IRQ_PORTF_INTA ? CONFIG_IRQ_PORTF_INTA : \
-				 (irq) == IRQ_PORTG_INTA ? CONFIG_IRQ_PORTG_INTA : \
-				 (irq) == IRQ_PORTH_INTA ? CONFIG_IRQ_PORTH_INTA : \
-				 -1)
-#elif defined(CONFIG_BF561)
-#define PRIO_GPIODEMUX(irq)	((irq) == IRQ_PROG0_INTA ? CONFIG_IRQ_PROG0_INTA : \
-				 (irq) == IRQ_PROG1_INTA ? CONFIG_IRQ_PROG1_INTA : \
-				 (irq) == IRQ_PROG2_INTA ? CONFIG_IRQ_PROG2_INTA : \
-				 -1)
+#ifdef CONFIG_BF561
 #define bfin_write_TIMER_DISABLE(val)	bfin_write_TMRS8_DISABLE(val)
 #define bfin_write_TIMER_ENABLE(val)	bfin_write_TMRS8_ENABLE(val)
 #define bfin_write_TIMER_STATUS(val)	bfin_write_TMRS8_STATUS(val)
 #define bfin_read_TIMER_STATUS()	bfin_read_TMRS8_STATUS()
 #elif defined(CONFIG_BF54x)
-#define PRIO_GPIODEMUX(irq)	((irq) == IRQ_PINT0 ? CONFIG_IRQ_PINT0 : \
-				 (irq) == IRQ_PINT1 ? CONFIG_IRQ_PINT1 : \
-				 (irq) == IRQ_PINT2 ? CONFIG_IRQ_PINT2 : \
-				 (irq) == IRQ_PINT3 ? CONFIG_IRQ_PINT3 : \
-				 -1)
 #define bfin_write_TIMER_DISABLE(val)	bfin_write_TIMER_DISABLE0(val)
 #define bfin_write_TIMER_ENABLE(val)	bfin_write_TIMER_ENABLE0(val)
 #define bfin_write_TIMER_STATUS(val)	bfin_write_TIMER_STATUS0(val)
 #define bfin_read_TIMER_STATUS(val)	bfin_read_TIMER_STATUS0(val)
-#else
-# error "no PRIO_GPIODEMUX() for this part"
 #endif
 
 #define __ipipe_root_tick_p(regs)	((regs->ipend & 0x10) != 0)
@@ -275,4 +245,6 @@ int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc);
 
 #endif /* !CONFIG_IPIPE */
 
+#define ipipe_update_tick_evtdev(evtdev)	do { } while (0)
+
 #endif	/* !__ASM_BLACKFIN_IPIPE_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/ipipe_base.h b/arch/blackfin/include/asm/ipipe_base.h
index cb1025a..3e8acbd 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/ipipe_base.h
+++ b/arch/blackfin/include/asm/ipipe_base.h
@@ -1,5 +1,5 @@
 /*   -*- linux-c -*-
- *   include/asm-blackfin/_baseipipe.h
+ *   include/asm-blackfin/ipipe_base.h
  *
  *   Copyright (C) 2007 Philippe Gerum.
  *
@@ -27,8 +27,9 @@
 #define IPIPE_NR_XIRQS		NR_IRQS
 #define IPIPE_IRQ_ISHIFT	5	/* 2^5 for 32bits arch. */
 
-/* Blackfin-specific, global domain flags */
-#define IPIPE_ROOTLOCK_FLAG	1	/* Lock pipeline for root */
+/* Blackfin-specific, per-cpu pipeline status */
+#define IPIPE_SYNCDEFER_FLAG	15
+#define IPIPE_SYNCDEFER_MASK	(1L << IPIPE_SYNCDEFER_MASK)
 
  /* Blackfin traps -- i.e. exception vector numbers */
 #define IPIPE_NR_FAULTS		52 /* We leave a gap after VEC_ILL_RES. */
@@ -48,11 +49,6 @@
 
 #ifndef __ASSEMBLY__
 
-#include <linux/bitops.h>
-
-extern int test_bit(int nr, const void *addr);
-
-
 extern unsigned long __ipipe_root_status; /* Alias to ipipe_root_cpudom_var(status) */
 
 static inline void __ipipe_stall_root(void)
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/irq.h b/arch/blackfin/include/asm/irq.h
index 3d97790..7c22d09 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/irq.h
+++ b/arch/blackfin/include/asm/irq.h
@@ -61,20 +61,38 @@ void __ipipe_restore_root(unsigned long flags);
 #define raw_irqs_disabled_flags(flags)	(!irqs_enabled_from_flags_hw(flags))
 #define local_test_iflag_hw(x)		irqs_enabled_from_flags_hw(x)
 
-#define local_save_flags(x)						\
-	do {								\
-		(x) = __ipipe_test_root() ? \
+#define local_save_flags(x)					 \
+	do {							 \
+		(x) = __ipipe_test_root() ?			 \
 			__all_masked_irq_flags : bfin_irq_flags; \
+		barrier();					 \
 	} while (0)
 
-#define local_irq_save(x)				\
-	do {						\
-		(x) = __ipipe_test_and_stall_root();	\
+#define local_irq_save(x)					 \
+	do {						 	 \
+		(x) = __ipipe_test_and_stall_root() ?		 \
+			__all_masked_irq_flags : bfin_irq_flags; \
+		barrier();					 \
 	} while (0)
 
-#define local_irq_restore(x)	__ipipe_restore_root(x)
-#define local_irq_disable()	__ipipe_stall_root()
-#define local_irq_enable()	__ipipe_unstall_root()
+static inline void local_irq_restore(unsigned long x)
+{
+	barrier();
+	__ipipe_restore_root(x == __all_masked_irq_flags);
+}
+
+#define local_irq_disable()			\
+	do {					\
+		__ipipe_stall_root();		\
+		barrier();			\
+	} while(0)
+
+static inline void local_irq_enable(void)
+{
+	barrier();
+	__ipipe_unstall_root();
+}
+
 #define irqs_disabled()		__ipipe_test_root()
 
 #define local_save_flags_hw(x) \
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index e721ce5..2920087 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -122,6 +122,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_MEMDIE              4
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
 #define TIF_FREEZE              6       /* is freezing for suspend */
+#define TIF_IRQ_SYNC            7       /* sync pipeline stage */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -130,6 +131,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_FREEZE             (1<<TIF_FREEZE)
+#define _TIF_IRQ_SYNC           (1<<TIF_IRQ_SYNC)
 
 #define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
 
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/kernel/ipipe.c b/arch/blackfin/kernel/ipipe.c
index 339be5a..a5de8d4 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/kernel/ipipe.c
+++ b/arch/blackfin/kernel/ipipe.c
@@ -35,14 +35,8 @@
 #include <asm/atomic.h>
 #include <asm/io.h>
 
-static int create_irq_threads;
-
 DEFINE_PER_CPU(struct pt_regs, __ipipe_tick_regs);
 
-static DEFINE_PER_CPU(unsigned long, pending_irqthread_mask);
-
-static DEFINE_PER_CPU(int [IVG13 + 1], pending_irq_count);
-
 asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs);
 
 static void __ipipe_no_irqtail(void);
@@ -93,6 +87,7 @@ void __ipipe_enable_pipeline(void)
  */
 void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 {
+	struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr();
 	struct ipipe_domain *this_domain, *next_domain;
 	struct list_head *head, *pos;
 	int m_ack, s = -1;
@@ -104,7 +99,6 @@ void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 	 * interrupt.
 	 */
 	m_ack = (regs == NULL || irq == IRQ_SYSTMR || irq == IRQ_CORETMR);
-
 	this_domain = ipipe_current_domain;
 
 	if (unlikely(test_bit(IPIPE_STICKY_FLAG, &this_domain->irqs[irq].control)))
@@ -114,49 +108,28 @@ void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 		next_domain = list_entry(head, struct ipipe_domain, p_link);
 		if (likely(test_bit(IPIPE_WIRED_FLAG, &next_domain->irqs[irq].control))) {
 			if (!m_ack && next_domain->irqs[irq].acknowledge != NULL)
-				next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
-			if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
-				s = __test_and_set_bit(IPIPE_STALL_FLAG,
-						       &ipipe_root_cpudom_var(status));
+				next_domain->irqs[irq].acknowledge(irq, irq_to_desc(irq));
+			if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status))
+				s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status);
 			__ipipe_dispatch_wired(next_domain, irq);
-				goto finalize;
-			return;
+			goto out;
 		}
 	}
 
 	/* Ack the interrupt. */
 
 	pos = head;
-
 	while (pos != &__ipipe_pipeline) {
 		next_domain = list_entry(pos, struct ipipe_domain, p_link);
-		/*
-		 * For each domain handling the incoming IRQ, mark it
-		 * as pending in its log.
-		 */
 		if (test_bit(IPIPE_HANDLE_FLAG, &next_domain->irqs[irq].control)) {
-			/*
-			 * Domains that handle this IRQ are polled for
-			 * acknowledging it by decreasing priority
-			 * order. The interrupt must be made pending
-			 * _first_ in the domain's status flags before
-			 * the PIC is unlocked.
-			 */
 			__ipipe_set_irq_pending(next_domain, irq);
-
 			if (!m_ack && next_domain->irqs[irq].acknowledge != NULL) {
-				next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
+				next_domain->irqs[irq].acknowledge(irq, irq_to_desc(irq));
 				m_ack = 1;
 			}
 		}
-
-		/*
-		 * If the domain does not want the IRQ to be passed
-		 * down the interrupt pipe, exit the loop now.
-		 */
 		if (!test_bit(IPIPE_PASS_FLAG, &next_domain->irqs[irq].control))
 			break;
-
 		pos = next_domain->p_link.next;
 	}
 
@@ -166,18 +139,24 @@ void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 	 * immediately to the current domain if the interrupt has been
 	 * marked as 'sticky'. This search does not go beyond the
 	 * current domain in the pipeline. We also enforce the
-	 * additional root stage lock (blackfin-specific). */
+	 * additional root stage lock (blackfin-specific).
+	 */
+	if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status))
+		s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status);
 
-	if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
-		s = __test_and_set_bit(IPIPE_STALL_FLAG,
-				       &ipipe_root_cpudom_var(status));
-finalize:
+	/*
+	 * If the interrupt preempted the head domain, then do not
+	 * even try to walk the pipeline, unless an interrupt is
+	 * pending for it.
+	 */
+	if (test_bit(IPIPE_AHEAD_FLAG, &this_domain->flags) &&
+	    ipipe_head_cpudom_var(irqpend_himask) == 0)
+		goto out;
 
 	__ipipe_walk_pipeline(head);
-
+out:
 	if (!s)
-		__clear_bit(IPIPE_STALL_FLAG,
-			    &ipipe_root_cpudom_var(status));
+		__clear_bit(IPIPE_STALL_FLAG, &p->status);
 }
 
 int __ipipe_check_root(void)
@@ -187,7 +166,7 @@ int __ipipe_check_root(void)
 
 void __ipipe_enable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
 {
-	struct irq_desc *desc = irq_desc + irq;
+	struct irq_desc *desc = irq_to_desc(irq);
 	int prio = desc->ic_prio;
 
 	desc->depth = 0;
@@ -199,7 +178,7 @@ EXPORT_SYMBOL(__ipipe_enable_irqdesc);
 
 void __ipipe_disable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
 {
-	struct irq_desc *desc = irq_desc + irq;
+	struct irq_desc *desc = irq_to_desc(irq);
 	int prio = desc->ic_prio;
 
 	if (ipd != &ipipe_root &&
@@ -236,15 +215,18 @@ int __ipipe_syscall_root(struct pt_regs *regs)
 {
 	unsigned long flags;
 
-	/* We need to run the IRQ tail hook whenever we don't
+	/*
+	 * We need to run the IRQ tail hook whenever we don't
 	 * propagate a syscall to higher domains, because we know that
 	 * important operations might be pending there (e.g. Xenomai
-	 * deferred rescheduling). */
+	 * deferred rescheduling).
+	 */
 
-	if (!__ipipe_syscall_watched_p(current, regs->orig_p0)) {
+	if (regs->orig_p0 < NR_syscalls) {
 		void (*hook)(void) = (void (*)(void))__ipipe_irq_tail_hook;
 		hook();
-		return 0;
+		if ((current->flags & PF_EVNOTIFY) == 0)
+			return 0;
 	}
 
 	/*
@@ -312,112 +294,46 @@ int ipipe_trigger_irq(unsigned irq)
 {
 	unsigned long flags;
 
+#ifdef CONFIG_IPIPE_DEBUG
 	if (irq >= IPIPE_NR_IRQS ||
 	    (ipipe_virtual_irq_p(irq)
 	     && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)))
 		return -EINVAL;
+#endif
 
 	local_irq_save_hw(flags);
-
 	__ipipe_handle_irq(irq, NULL);
-
 	local_irq_restore_hw(flags);
 
 	return 1;
 }
 
-/* Move Linux IRQ to threads. */
-
-static int do_irqd(void *__desc)
+asmlinkage void __ipipe_sync_root(void)
 {
-	struct irq_desc *desc = __desc;
-	unsigned irq = desc - irq_desc;
-	int thrprio = desc->thr_prio;
-	int thrmask = 1 << thrprio;
-	int cpu = smp_processor_id();
-	cpumask_t cpumask;
-
-	sigfillset(&current->blocked);
-	current->flags |= PF_NOFREEZE;
-	cpumask = cpumask_of_cpu(cpu);
-	set_cpus_allowed(current, cpumask);
-	ipipe_setscheduler_root(current, SCHED_FIFO, 50 + thrprio);
-
-	while (!kthread_should_stop()) {
-		local_irq_disable();
-		if (!(desc->status & IRQ_SCHEDULED)) {
-			set_current_state(TASK_INTERRUPTIBLE);
-resched:
-			local_irq_enable();
-			schedule();
-			local_irq_disable();
-		}
-		__set_current_state(TASK_RUNNING);
-		/*
-		 * If higher priority interrupt servers are ready to
-		 * run, reschedule immediately. We need this for the
-		 * GPIO demux IRQ handler to unmask the interrupt line
-		 * _last_, after all GPIO IRQs have run.
-		 */
-		if (per_cpu(pending_irqthread_mask, cpu) & ~(thrmask|(thrmask-1)))
-			goto resched;
-		if (--per_cpu(pending_irq_count[thrprio], cpu) == 0)
-			per_cpu(pending_irqthread_mask, cpu) &= ~thrmask;
-		desc->status &= ~IRQ_SCHEDULED;
-		desc->thr_handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs));
-		local_irq_enable();
-	}
-	__set_current_state(TASK_RUNNING);
-	return 0;
-}
+	unsigned long flags;
 
-static void kick_irqd(unsigned irq, void *cookie)
-{
-	struct irq_desc *desc = irq_desc + irq;
-	int thrprio = desc->thr_prio;
-	int thrmask = 1 << thrprio;
-	int cpu = smp_processor_id();
-
-	if (!(desc->status & IRQ_SCHEDULED)) {
-		desc->status |= IRQ_SCHEDULED;
-		per_cpu(pending_irqthread_mask, cpu) |= thrmask;
-		++per_cpu(pending_irq_count[thrprio], cpu);
-		wake_up_process(desc->thread);
-	}
-}
+	BUG_ON(irqs_disabled());
 
-int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc)
-{
-	if (desc->thread || !create_irq_threads)
-		return 0;
-
-	desc->thread = kthread_create(do_irqd, desc, "IRQ %d", irq);
-	if (desc->thread == NULL) {
-		printk(KERN_ERR "irqd: could not create IRQ thread %d!\n", irq);
-		return -ENOMEM;
-	}
+	local_irq_save_hw(flags);
 
-	wake_up_process(desc->thread);
+	clear_thread_flag(TIF_IRQ_SYNC);
 
-	desc->thr_handler = ipipe_root_domain->irqs[irq].handler;
-	ipipe_root_domain->irqs[irq].handler = &kick_irqd;
+	if (ipipe_root_cpudom_var(irqpend_himask) != 0)
+		__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
 
-	return 0;
+	local_irq_restore_hw(flags);
 }
 
-void __init ipipe_init_irq_threads(void)
+void ___ipipe_sync_pipeline(unsigned long syncmask)
 {
-	unsigned irq;
-	struct irq_desc *desc;
-
-	create_irq_threads = 1;
+	struct ipipe_domain *ipd = ipipe_current_domain;
 
-	for (irq = 0; irq < NR_IRQS; irq++) {
-		desc = irq_desc + irq;
-		if (desc->action != NULL ||
-			(desc->status & IRQ_NOREQUEST) != 0)
-			ipipe_start_irq_thread(irq, desc);
+	if (ipd == ipipe_root_domain) {
+		if (test_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status)))
+			return;
 	}
+
+	__ipipe_sync_stage(syncmask);
 }
 
 EXPORT_SYMBOL(show_stack);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c
index 75724ee..7fd1265 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/kernel/irqchip.c
+++ b/arch/blackfin/kernel/irqchip.c
@@ -144,11 +144,15 @@ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
 #endif
 	generic_handle_irq(irq);
 
-#ifndef CONFIG_IPIPE	/* Useless and bugous over the I-pipe: IRQs are threaded. */
-	/* If we're the only interrupt running (ignoring IRQ15 which is for
-	   syscalls), lower our priority to IRQ14 so that softirqs run at
-	   that level.  If there's another, lower-level interrupt, irq_exit
-	   will defer softirqs to that.  */
+#ifndef CONFIG_IPIPE
+	/*
+	 * If we're the only interrupt running (ignoring IRQ15 which
+	 * is for syscalls), lower our priority to IRQ14 so that
+	 * softirqs run at that level.  If there's another,
+	 * lower-level interrupt, irq_exit will defer softirqs to
+	 * that. If the interrupt pipeline is enabled, we are already
+	 * running at IRQ14 priority, so we don't need this code.
+	 */
 	CSYNC();
 	pending = bfin_read_IPEND() & ~0x8000;
 	other_ints = pending & (pending - 1);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
index 172b4c5..1bbacfb 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/kernel/time.c
+++ b/arch/blackfin/kernel/time.c
@@ -134,7 +134,10 @@ irqreturn_t timer_interrupt(int irq, void *dummy)
 
 	write_seqlock(&xtime_lock);
 #if defined(CONFIG_TICK_SOURCE_SYSTMR0) && !defined(CONFIG_IPIPE)
-/* FIXME: Here TIMIL0 is not set when IPIPE enabled, why? */
+	/*
+	 * TIMIL0 is latched in __ipipe_grab_irq() when the I-Pipe is
+	 * enabled.
+	 */
 	if (get_gptimer_status(0) & TIMER_STATUS_TIMIL0) {
 #endif
 		do_timer(1);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 88de053..219ee5f 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -600,6 +600,19 @@ ENTRY(_system_call)
 	p2 = [p2];
 
 	[p2+(TASK_THREAD+THREAD_KSP)] = sp;
+#ifdef CONFIG_IPIPE
+	r0 = sp;
+	SP += -12;
+	call ___ipipe_syscall_root; 
+	SP += 12;
+	cc = r0 == 1;
+	if cc jump .Lsyscall_really_exit;
+	cc = r0 == -1;
+	if cc jump .Lresume_userspace;
+	r3 = [sp + PT_R3]; 
+	r4 = [sp + PT_R4]; 
+	p0 = [sp + PT_ORIG_P0]; 
+#endif /* CONFIG_IPIPE */
 
 	/* Check the System Call */
 	r7 = __NR_syscall;
@@ -654,6 +667,17 @@ ENTRY(_system_call)
 	r7 =  r7 & r4;
 
 .Lsyscall_resched:
+#ifdef CONFIG_IPIPE
+	cc = BITTST(r7, TIF_IRQ_SYNC);
+	if !cc jump .Lsyscall_no_irqsync;
+	[--sp] = reti;
+	r0 = [sp++];
+	SP += -12;
+	call ___ipipe_sync_root;
+	SP += 12;
+	jump .Lresume_userspace_1;
+.Lsyscall_no_irqsync:
+#endif	
 	cc = BITTST(r7, TIF_NEED_RESCHED);
 	if !cc jump .Lsyscall_sigpending;
 
@@ -685,6 +709,10 @@ ENTRY(_system_call)
 .Lsyscall_really_exit:
 	r5 = [sp + PT_RESERVED];
 	rets = r5;
+#ifdef CONFIG_IPIPE
+	[--sp] = reti;
+	r5 = [sp++];
+#endif /* CONFIG_IPIPE */
 	rts;
 ENDPROC(_system_call)
 
@@ -771,6 +799,15 @@ _new_old_task:
 ENDPROC(_resume)
 
 ENTRY(_ret_from_exception)
+#ifdef CONFIG_IPIPE
+	[--sp] = rets;
+	SP += -12;
+	call ___ipipe_check_root
+	SP += 12
+	rets = [sp++];
+	cc = r0 == 0;
+	if cc jump 4f;                /* not on behalf of Linux, get out */
+#endif /* CONFIG_IPIPE */
 	p2.l = lo(IPEND);
 	p2.h = hi(IPEND);
 
@@ -827,6 +864,28 @@ ENTRY(_ret_from_exception)
 	rts;
 ENDPROC(_ret_from_exception)
 
+#ifdef CONFIG_IPIPE
+
+_sync_root_irqs:
+	[--sp] = reti;		/* Reenable interrupts */
+	r0 = [sp++];
+	jump.l ___ipipe_sync_root
+	
+_resume_kernel_from_int:
+	r0.l = _sync_root_irqs
+	r0.h = _sync_root_irqs
+	[--sp] = rets;
+	[--sp] = ( r7:4, p5:3 );
+	SP += -12;
+	call ___ipipe_call_irqtail
+	SP += 12;
+	( r7:4, p5:3 ) = [sp++];
+	rets = [sp++];
+	rts
+#else
+#define _resume_kernel_from_int	 2f
+#endif
+	
 ENTRY(_return_from_int)
 	/* If someone else already raised IRQ 15, do nothing.  */
 	csync;
@@ -848,7 +907,7 @@ ENTRY(_return_from_int)
 	r1 = r0 - r1;
 	r2 = r0 & r1;
 	cc = r2 == 0;
-	if !cc jump 2f;
+	if !cc jump _resume_kernel_from_int;
 
 	/* Lower the interrupt level to 15.  */
 	p0.l = lo(EVT15);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index 43c4eb9..0069c2d 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/mach-common/interrupt.S
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -235,6 +235,7 @@ ENDPROC(_evt_system_call)
 
 #ifdef CONFIG_IPIPE
 ENTRY(___ipipe_call_irqtail)
+	p0 = r0;
 	r0.l = 1f;
 	r0.h = 1f;
 	reti = r0;
@@ -242,9 +243,6 @@ ENTRY(___ipipe_call_irqtail)
 1:
 	[--sp] = rets;
 	[--sp] = ( r7:4, p5:3 );
-	p0.l = ___ipipe_irq_tail_hook;
-	p0.h = ___ipipe_irq_tail_hook;
-	p0 = [p0];
 	sp += -12;
 	call (p0);
 	sp += 12;
@@ -259,7 +257,7 @@ ENTRY(___ipipe_call_irqtail)
 	p0.h = hi(EVT14);
 	[p0] = r0;
 	csync;
-	r0 = 0x401f;
+	r0 = 0x401f (z);
 	sti r0;
 	raise 14;
 	[--sp] = reti;          /* IRQs on. */
@@ -277,11 +275,7 @@ ENTRY(___ipipe_call_irqtail)
 	p0.h = _bfin_irq_flags;
 	r0 = [p0];
 	sti r0;
-#if 0 /* FIXME: this actually raises scheduling latencies */
-	/* Reenable interrupts */
-	[--sp] = reti;
-	r0 = [sp++];
-#endif
 	rts;
 ENDPROC(___ipipe_call_irqtail)
+
 #endif /* CONFIG_IPIPE */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/mach-common/ints-priority.c b/arch/blackfin/mach-common/ints-priority.c
index 2024945..469fc27 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/mach-common/ints-priority.c
+++ b/arch/blackfin/mach-common/ints-priority.c
@@ -161,11 +161,15 @@ static void bfin_core_unmask_irq(unsigned int irq)
 
 static void bfin_internal_mask_irq(unsigned int irq)
 {
+	unsigned long flags;
+	
 #ifdef CONFIG_BF53x
+	local_irq_save_hw(flags);
 	bfin_write_SIC_IMASK(bfin_read_SIC_IMASK() &
 			     ~(1 << SIC_SYSIRQ(irq)));
 #else
 	unsigned mask_bank, mask_bit;
+	local_irq_save_hw(flags);
 	mask_bank = SIC_SYSIRQ(irq) / 32;
 	mask_bit = SIC_SYSIRQ(irq) % 32;
 	bfin_write_SIC_IMASK(mask_bank, bfin_read_SIC_IMASK(mask_bank) &
@@ -175,15 +179,20 @@ static void bfin_internal_mask_irq(unsigned int irq)
 			     ~(1 << mask_bit));
 #endif
 #endif
+	local_irq_restore_hw(flags);
 }
 
 static void bfin_internal_unmask_irq(unsigned int irq)
 {
+	unsigned long flags;
+	
 #ifdef CONFIG_BF53x
+	local_irq_save_hw(flags);
 	bfin_write_SIC_IMASK(bfin_read_SIC_IMASK() |
 			     (1 << SIC_SYSIRQ(irq)));
 #else
 	unsigned mask_bank, mask_bit;
+	local_irq_save_hw(flags);
 	mask_bank = SIC_SYSIRQ(irq) / 32;
 	mask_bit = SIC_SYSIRQ(irq) % 32;
 	bfin_write_SIC_IMASK(mask_bank, bfin_read_SIC_IMASK(mask_bank) |
@@ -193,6 +202,7 @@ static void bfin_internal_unmask_irq(unsigned int irq)
 			     (1 << mask_bit));
 #endif
 #endif
+	local_irq_restore_hw(flags);
 }
 
 #ifdef CONFIG_PM
@@ -390,7 +400,7 @@ static void bfin_demux_error_irq(unsigned int int_err_irq,
 static inline void bfin_set_irq_handler(unsigned irq, irq_flow_handler_t handle)
 {
 #ifdef CONFIG_IPIPE
-	_set_irq_handler(irq, handle_edge_irq);
+	_set_irq_handler(irq, handle_level_irq);
 #else
 	struct irq_desc *desc = irq_desc + irq;
 	/* May not call generic set_irq_handler() due to spinlock
@@ -1055,13 +1065,18 @@ int __init init_arch_irq(void)
 #endif
 		default:
 #ifdef CONFIG_IPIPE
-	/*
-	 * We want internal interrupt sources to be masked, because
-	 * ISRs may trigger interrupts recursively (e.g. DMA), but
-	 * interrupts are _not_ masked at CPU level. So let's handle
-	 * them as level interrupts.
-	 */
-			set_irq_handler(irq, handle_level_irq);
+			/*
+			 * We want internal interrupt sources to be
+			 * masked, because ISRs may trigger interrupts
+			 * recursively (e.g. DMA), but interrupts are
+			 * _not_ masked at CPU level. So let's handle
+			 * most of them as level interrupts, except
+			 * the timer interrupt which is special.
+			 */
+			if (irq == IRQ_SYSTMR || irq == IRQ_CORETMR)
+				set_irq_handler(irq, handle_simple_irq);
+			else
+				set_irq_handler(irq, handle_level_irq);
 #else /* !CONFIG_IPIPE */
 			set_irq_handler(irq, handle_simple_irq);
 #endif /* !CONFIG_IPIPE */
@@ -1123,9 +1138,8 @@ int __init init_arch_irq(void)
 
 #ifdef CONFIG_IPIPE
 	for (irq = 0; irq < NR_IRQS; irq++) {
-		struct irq_desc *desc = irq_desc + irq;
+		struct irq_desc *desc = irq_to_desc(irq);
 		desc->ic_prio = __ipipe_get_irq_priority(irq);
-		desc->thr_prio = __ipipe_get_irqthread_priority(irq);
 	}
 #endif /* CONFIG_IPIPE */
 
@@ -1208,76 +1222,21 @@ int __ipipe_get_irq_priority(unsigned irq)
 	return IVG15;
 }
 
-int __ipipe_get_irqthread_priority(unsigned irq)
-{
-	int ient, prio;
-	int demux_irq;
-
-	/* The returned priority value is rescaled to [0..IVG13+1]
-	 * with 0 being the lowest effective priority level. */
-
-	if (irq <= IRQ_CORETMR)
-		return IVG13 - irq + 1;
-
-	/* GPIO IRQs are given the priority of the demux
-	 * interrupt. */
-	if (IS_GPIOIRQ(irq)) {
-#if defined(CONFIG_BF54x)
-		u32 bank = PINT_2_BANK(irq2pint_lut[irq - SYS_IRQS]);
-		demux_irq = (bank == 0 ? IRQ_PINT0 :
-				bank == 1 ? IRQ_PINT1 :
-				bank == 2 ? IRQ_PINT2 :
-				IRQ_PINT3);
-#elif defined(CONFIG_BF561)
-		demux_irq = (irq >= IRQ_PF32 ? IRQ_PROG2_INTA :
-				irq >= IRQ_PF16 ? IRQ_PROG1_INTA :
-				IRQ_PROG0_INTA);
-#elif defined(CONFIG_BF52x)
-		demux_irq = (irq >= IRQ_PH0 ? IRQ_PORTH_INTA :
-				irq >= IRQ_PG0 ? IRQ_PORTG_INTA :
-				IRQ_PORTF_INTA);
-#else
-		demux_irq = irq;
-#endif
-		return IVG13 - PRIO_GPIODEMUX(demux_irq) + 1;
-	}
-
-	/* The GPIO demux interrupt is given a lower priority
-	 * than the GPIO IRQs, so that its threaded handler
-	 * unmasks the interrupt line after the decoded IRQs
-	 * have been processed. */
-	prio = PRIO_GPIODEMUX(irq);
-	/* demux irq? */
-	if (prio != -1)
-		return IVG13 - prio;
-
-	for (ient = 0; ient < NR_PERI_INTS; ient++) {
-		struct ivgx *ivg = ivg_table + ient;
-		if (ivg->irqno == irq) {
-			for (prio = 0; prio <= IVG13-IVG7; prio++) {
-				if (ivg7_13[prio].ifirst <= ivg &&
-				    ivg7_13[prio].istop > ivg)
-					return IVG7 - prio;
-			}
-		}
-	}
-
-	return 0;
-}
-
 /* Hw interrupts are disabled on entry (check SAVE_CONTEXT). */
 #ifdef CONFIG_DO_IRQ_L1
 __attribute__((l1_text))
 #endif
 asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs)
 {
+	struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr();
+	struct ipipe_domain *this_domain = ipipe_current_domain;
 	struct ivgx *ivg_stop = ivg7_13[vec-IVG7].istop;
 	struct ivgx *ivg = ivg7_13[vec-IVG7].ifirst;
-	int irq;
+	int irq, s;
 
 	if (likely(vec == EVT_IVTMR_P)) {
 		irq = IRQ_CORETMR;
-		goto handle_irq;
+		goto core_tick;
 	}
 
 	SSYNC();
@@ -1319,24 +1278,39 @@ asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs)
 	irq = ivg->irqno;
 
 	if (irq == IRQ_SYSTMR) {
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+	core_tick:
+#else
 		bfin_write_TIMER_STATUS(1); /* Latch TIMIL0 */
+#endif
 		/* This is basically what we need from the register frame. */
 		__raw_get_cpu_var(__ipipe_tick_regs).ipend = regs->ipend;
 		__raw_get_cpu_var(__ipipe_tick_regs).pc = regs->pc;
-		if (!ipipe_root_domain_p)
-			__raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10;
-		else
+		if (this_domain != ipipe_root_domain)
 			__raw_get_cpu_var(__ipipe_tick_regs).ipend &= ~0x10;
+		else
+			__raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10;
 	}
 
-handle_irq:
+#ifndef CONFIG_GENERIC_CLOCKEVENTS
+core_tick:
+#endif
+	if (this_domain == ipipe_root_domain) {
+		s = __test_and_set_bit(IPIPE_SYNCDEFER_FLAG, &p->status);
+		barrier();
+	}
 
 	ipipe_trace_irq_entry(irq);
 	__ipipe_handle_irq(irq, regs);
-       ipipe_trace_irq_exit(irq);
+	ipipe_trace_irq_exit(irq);
 
-       if (ipipe_root_domain_p)
-		return !test_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status));
+	if (this_domain == ipipe_root_domain) {
+		set_thread_flag(TIF_IRQ_SYNC);
+		if (!s) {
+			__clear_bit(IPIPE_SYNCDEFER_FLAG, &p->status);
+			return !test_bit(IPIPE_STALL_FLAG, &p->status);
+		}
+	}
 
        return 0;
 }
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index 71a9e6b..bb703c2 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -1145,6 +1145,52 @@ static void bfin_serial_console_putchar(struct uart_port *port, int ch)
 	SSYNC();
 }
 
+#ifdef CONFIG_IPIPE
+
+#include <stdarg.h>
+
+void __ipipe_serial_debug(const char *fmt, ...)
+{
+	struct bfin_serial_port *uart = &bfin_serial_ports[0];
+	unsigned short status, tmp;
+	int flags, i, count;
+	char buf[128];
+	va_list ap;
+
+	va_start(ap, fmt);
+	vsprintf(buf, fmt, ap);
+	va_end(ap);
+	count = strlen(buf);
+
+	local_irq_save_hw(flags);
+
+	for (i = 0; i < count; i++) {
+		do {
+			status = UART_GET_LSR(uart);
+		} while (!(status & THRE));
+
+#ifndef CONFIG_BF54x
+		tmp = UART_GET_LCR(uart);
+		tmp &= ~DLAB;
+		UART_PUT_LCR(uart, tmp);
+#endif
+
+		UART_PUT_CHAR(uart, buf[i]);
+		if (buf[i] == '\n') {
+			do {
+				status = UART_GET_LSR(uart);
+			} while(!(status & THRE));
+			UART_PUT_CHAR(uart, '\r');
+		}
+	}
+
+	local_irq_restore_hw(flags);
+}
+
+EXPORT_SYMBOL(__ipipe_serial_debug);
+
+#endif /* CONFIG_IPIPE */
+
 /*
  * Interrupts are disabled on entering
  */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/asm-generic/cmpxchg-local.h b/include/asm-generic/cmpxchg-local.h
index b2ba2fc..ed01ab9 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/Makefile
+++ b/Makefile
@@ -525,6 +525,10 @@ endif
 # Arch Makefiles may override this setting
 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
 
+ifdef CONFIG_IPIPE_TRACE_MCOUNT
+KBUILD_CFLAGS	+= -pg
+endif
+
 ifdef CONFIG_FRAME_POINTER
 KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
 else
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 8f1f97d..7c2c966 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -373,6 +373,8 @@ source "arch/blackfin/mach-bf537/Kconfig"
 source "arch/blackfin/mach-bf538/Kconfig"
 source "arch/blackfin/mach-bf548/Kconfig"
 
+source "kernel/ipipe/Kconfig"
+
 menu "Board customizations"
 
 config CMDLINE_BOOL
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/arch/blackfin/include/asm/ipipe.h b/arch/blackfin/include/asm/ipipe.h
index 76f53d8..39a41e8 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/asm-generic/cmpxchg-local.h
+++ b/include/asm-generic/cmpxchg-local.h
@@ -20,7 +20,7 @@ static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
 	if (size == 8 && sizeof(unsigned long) != 8)
 		wrong_size_cmpxchg(ptr);
 
-	local_irq_save(flags);
+	local_irq_save_hw(flags);
 	switch (size) {
 	case 1: prev = *(u8 *)ptr;
 		if (prev == old)
@@ -41,7 +41,7 @@ static inline unsigned long __cmpxchg_local_generic(volatile void *ptr,
 	default:
 		wrong_size_cmpxchg(ptr);
 	}
-	local_irq_restore(flags);
+	local_irq_restore_hw(flags);
 	return prev;
 }
 
@@ -54,11 +54,11 @@ static inline u64 __cmpxchg64_local_generic(volatile void *ptr,
 	u64 prev;
 	unsigned long flags;
 
-	local_irq_save(flags);
+	local_irq_save_hw(flags);
 	prev = *(u64 *)ptr;
 	if (prev == old)
 		*(u64 *)ptr = new;
-	local_irq_restore(flags);
+	local_irq_restore_hw(flags);
 	return prev;
 }
 
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/hardirq.h b/include/linux/hardirq.h
index 181006c..bc69d94 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -161,7 +161,22 @@ extern void irq_enter(void);
  */
 extern void irq_exit(void);
 
-#define nmi_enter()		do { lockdep_off(); __irq_enter(); } while (0)
-#define nmi_exit()		do { __irq_exit(); lockdep_on(); } while (0)
+#define nmi_enter() 					\
+	do {						\
+		ipipe_nmi_enter();			\
+		if (ipipe_root_domain_p) {		\
+			lockdep_off();			\
+			__irq_enter();			\
+		}					\
+	} while (0)
+
+#define nmi_exit()					\
+	do {						\
+		if (ipipe_root_domain_p) {		\
+			__irq_exit();			\
+			lockdep_on();			\
+		}					\
+		ipipe_nmi_exit();			\
+	} while (0)
 
 #endif /* LINUX_HARDIRQ_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/ipipe.h b/include/linux/ipipe.h
new file mode 100644
index 0000000..065a43d
--- /dev/null
+++ b/include/linux/ipipe.h
@@ -0,0 +1,673 @@
+/* -*- linux-c -*-
+ * include/linux/ipipe.h
+ *
+ * Copyright (C) 2002-2007 Philippe Gerum.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __LINUX_IPIPE_H
+#define __LINUX_IPIPE_H
+
+#include <linux/spinlock.h>
+#include <linux/cache.h>
+#include <linux/percpu.h>
+#include <linux/mutex.h>
+#include <linux/linkage.h>
+#include <linux/ipipe_base.h>
+#include <linux/ipipe_compat.h>
+#include <asm/ipipe.h>
+
+#ifdef CONFIG_IPIPE_DEBUG_CONTEXT
+
+#include <linux/cpumask.h>
+#include <asm/system.h>
+
+static inline int ipipe_disable_context_check(int cpu)
+{
+	return xchg(&per_cpu(ipipe_percpu_context_check, cpu), 0);
+}
+
+static inline void ipipe_restore_context_check(int cpu, int old_state)
+{
+	per_cpu(ipipe_percpu_context_check, cpu) = old_state;
+}
+
+static inline void ipipe_context_check_off(void)
+{
+	int cpu;
+	for_each_online_cpu(cpu)
+		per_cpu(ipipe_percpu_context_check, cpu) = 0;
+}
+
+#else	/* !CONFIG_IPIPE_DEBUG_CONTEXT */
+
+static inline int ipipe_disable_context_check(int cpu)
+{
+	return 0;
+}
+
+static inline void ipipe_restore_context_check(int cpu, int old_state) { }
+
+static inline void ipipe_context_check_off(void) { }
+
+#endif	/* !CONFIG_IPIPE_DEBUG_CONTEXT */
+
+#ifdef CONFIG_IPIPE
+
+/*
+ * Sanity check: IPIPE_VIRQ_BASE depends on CONFIG_NR_CPUS, and if the
+ * latter gets too large, we fail to map the virtual interrupts.
+ */
+#if IPIPE_VIRQ_BASE / BITS_PER_LONG > BITS_PER_LONG
+#error "CONFIG_NR_CPUS is too large, please lower it."
+#endif
+
+#define IPIPE_VERSION_STRING	IPIPE_ARCH_STRING
+#define IPIPE_RELEASE_NUMBER	((IPIPE_MAJOR_NUMBER << 16) | \
+				 (IPIPE_MINOR_NUMBER <<  8) | \
+				 (IPIPE_PATCH_NUMBER))
+
+#ifndef BROKEN_BUILTIN_RETURN_ADDRESS
+#define __BUILTIN_RETURN_ADDRESS0 ((unsigned long)__builtin_return_address(0))
+#define __BUILTIN_RETURN_ADDRESS1 ((unsigned long)__builtin_return_address(1))
+#endif /* !BUILTIN_RETURN_ADDRESS */
+
+#define IPIPE_ROOT_PRIO		100
+#define IPIPE_ROOT_ID		0
+#define IPIPE_ROOT_NPTDKEYS	4	/* Must be <= BITS_PER_LONG */
+
+#define IPIPE_RESET_TIMER	0x1
+#define IPIPE_GRAB_TIMER	0x2
+
+/* Global domain flags */
+#define IPIPE_SPRINTK_FLAG	0	/* Synchronous printk() allowed */
+#define IPIPE_AHEAD_FLAG	1	/* Domain always heads the pipeline */
+
+/* Interrupt control bits */
+#define IPIPE_HANDLE_FLAG	0
+#define IPIPE_PASS_FLAG		1
+#define IPIPE_ENABLE_FLAG	2
+#define IPIPE_DYNAMIC_FLAG	IPIPE_HANDLE_FLAG
+#define IPIPE_STICKY_FLAG	3
+#define IPIPE_SYSTEM_FLAG	4
+#define IPIPE_LOCK_FLAG		5
+#define IPIPE_WIRED_FLAG	6
+#define IPIPE_EXCLUSIVE_FLAG	7
+
+#define IPIPE_HANDLE_MASK	(1 << IPIPE_HANDLE_FLAG)
+#define IPIPE_PASS_MASK		(1 << IPIPE_PASS_FLAG)
+#define IPIPE_ENABLE_MASK	(1 << IPIPE_ENABLE_FLAG)
+#define IPIPE_DYNAMIC_MASK	IPIPE_HANDLE_MASK
+#define IPIPE_STICKY_MASK	(1 << IPIPE_STICKY_FLAG)
+#define IPIPE_SYSTEM_MASK	(1 << IPIPE_SYSTEM_FLAG)
+#define IPIPE_LOCK_MASK		(1 << IPIPE_LOCK_FLAG)
+#define IPIPE_WIRED_MASK	(1 << IPIPE_WIRED_FLAG)
+#define IPIPE_EXCLUSIVE_MASK	(1 << IPIPE_EXCLUSIVE_FLAG)
+
+#define IPIPE_DEFAULT_MASK	(IPIPE_HANDLE_MASK|IPIPE_PASS_MASK)
+#define IPIPE_STDROOT_MASK	(IPIPE_HANDLE_MASK|IPIPE_PASS_MASK|IPIPE_SYSTEM_MASK)
+
+#define IPIPE_EVENT_SELF        0x80000000
+
+#define IPIPE_NR_CPUS		NR_CPUS
+
+#define ipipe_current_domain	ipipe_cpu_var(ipipe_percpu_domain)
+
+#define ipipe_virtual_irq_p(irq)	((irq) >= IPIPE_VIRQ_BASE && \
+					 (irq) < IPIPE_NR_IRQS)
+
+#define IPIPE_SAME_HANDLER	((ipipe_irq_handler_t)(-1))
+
+struct irq_desc;
+
+typedef void (*ipipe_irq_ackfn_t)(unsigned irq, struct irq_desc *desc);
+
+typedef int (*ipipe_event_handler_t)(unsigned event,
+				     struct ipipe_domain *from,
+				     void *data);
+struct ipipe_domain {
+
+	int slot;			/* Slot number in percpu domain data array. */
+	struct list_head p_link;	/* Link in pipeline */
+	ipipe_event_handler_t evhand[IPIPE_NR_EVENTS]; /* Event handlers. */
+	unsigned long long evself;	/* Self-monitored event bits. */
+
+	struct {
+		unsigned long control;
+		ipipe_irq_ackfn_t acknowledge;
+		ipipe_irq_handler_t handler;
+		void *cookie;
+	} ____cacheline_aligned irqs[IPIPE_NR_IRQS];
+
+	int priority;
+	void *pdd;
+	unsigned long flags;
+	unsigned domid;
+	const char *name;
+	struct mutex mutex;
+};
+
+#define IPIPE_HEAD_PRIORITY	(-1) /* For domains always heading the pipeline */
+
+struct ipipe_domain_attr {
+
+	unsigned domid;		/* Domain identifier -- Magic value set by caller */
+	const char *name;	/* Domain name -- Warning: won't be dup'ed! */
+	int priority;		/* Priority in interrupt pipeline */
+	void (*entry) (void);	/* Domain entry point */
+	void *pdd;		/* Per-domain (opaque) data pointer */
+};
+
+#ifdef CONFIG_SMP
+/* These ops must start and complete on the same CPU: care for
+ * migration. */
+#define set_bit_safe(b, a)						\
+		({ unsigned long __flags;				\
+		local_irq_save_hw_notrace(__flags);			\
+		__set_bit(b, a);					\
+		local_irq_restore_hw_notrace(__flags); })
+#define test_and_set_bit_safe(b, a)					\
+		({ unsigned long __flags, __x;				\
+		local_irq_save_hw_notrace(__flags);			\
+		__x = __test_and_set_bit(b, a);				\
+		local_irq_restore_hw_notrace(__flags); __x; })
+#define clear_bit_safe(b, a)						\
+		({ unsigned long __flags;				\
+		local_irq_save_hw_notrace(__flags);			\
+		__clear_bit(b, a);					\
+		local_irq_restore_hw_notrace(__flags); })
+#else
+#define set_bit_safe(b, a)		set_bit(b, a)
+#define test_and_set_bit_safe(b, a)	test_and_set_bit(b, a)
+#define clear_bit_safe(b, a)		clear_bit(b, a)
+#endif
+
+#define __ipipe_irq_cookie(ipd, irq)		(ipd)->irqs[irq].cookie
+#define __ipipe_irq_handler(ipd, irq)		(ipd)->irqs[irq].handler
+#define __ipipe_cpudata_irq_hits(ipd, cpu, irq)	ipipe_percpudom(ipd, irqall, cpu)[irq]
+
+extern unsigned __ipipe_printk_virq;
+
+extern unsigned long __ipipe_virtual_irq_map;
+
+extern struct list_head __ipipe_pipeline;
+
+extern int __ipipe_event_monitors[];
+
+/* Private interface */
+
+void ipipe_init(void);
+
+#ifdef CONFIG_PROC_FS
+void ipipe_init_proc(void);
+
+#ifdef CONFIG_IPIPE_TRACE
+void __ipipe_init_tracer(void);
+#else /* !CONFIG_IPIPE_TRACE */
+#define __ipipe_init_tracer()       do { } while(0)
+#endif /* CONFIG_IPIPE_TRACE */
+
+#else	/* !CONFIG_PROC_FS */
+#define ipipe_init_proc()	do { } while(0)
+#endif	/* CONFIG_PROC_FS */
+
+void __ipipe_init_stage(struct ipipe_domain *ipd);
+
+void __ipipe_cleanup_domain(struct ipipe_domain *ipd);
+
+void __ipipe_add_domain_proc(struct ipipe_domain *ipd);
+
+void __ipipe_remove_domain_proc(struct ipipe_domain *ipd);
+
+void __ipipe_flush_printk(unsigned irq, void *cookie);
+
+void __ipipe_walk_pipeline(struct list_head *pos);
+
+void __ipipe_pend_irq(unsigned irq, struct list_head *head);
+
+int __ipipe_dispatch_event(unsigned event, void *data);
+
+void __ipipe_dispatch_wired_nocheck(struct ipipe_domain *head, unsigned irq);
+
+void __ipipe_dispatch_wired(struct ipipe_domain *head, unsigned irq);
+
+void __ipipe_sync_stage(unsigned long syncmask);
+
+void __ipipe_set_irq_pending(struct ipipe_domain *ipd, unsigned irq);
+
+void __ipipe_lock_irq(struct ipipe_domain *ipd, int cpu, unsigned irq);
+
+void __ipipe_unlock_irq(struct ipipe_domain *ipd, unsigned irq);
+
+void __ipipe_pin_range_globally(unsigned long start, unsigned long end);
+
+/* Must be called hw IRQs off. */
+static inline void ipipe_irq_lock(unsigned irq)
+{
+	__ipipe_lock_irq(ipipe_current_domain, ipipe_processor_id(), irq);
+}
+
+/* Must be called hw IRQs off. */
+static inline void ipipe_irq_unlock(unsigned irq)
+{
+	__ipipe_unlock_irq(ipipe_current_domain, irq);
+}
+
+#ifndef __ipipe_sync_pipeline
+#define __ipipe_sync_pipeline(syncmask) __ipipe_sync_stage(syncmask)
+#endif
+
+#ifndef __ipipe_run_irqtail
+#define __ipipe_run_irqtail() do { } while(0)
+#endif
+
+#define __ipipe_pipeline_head_p(ipd) (&(ipd)->p_link == __ipipe_pipeline.next)
+
+/*
+ * Keep the following as a macro, so that client code could check for
+ * the support of the invariant pipeline head optimization.
+ */
+#define __ipipe_pipeline_head() \
+	list_entry(__ipipe_pipeline.next, struct ipipe_domain, p_link)
+
+#define __ipipe_event_monitored_p(ev) \
+	(__ipipe_event_monitors[ev] > 0 || (ipipe_current_domain->evself & (1LL << ev)))
+
+#ifdef CONFIG_SMP
+
+cpumask_t __ipipe_set_irq_affinity(unsigned irq,
+				   cpumask_t cpumask);
+
+int __ipipe_send_ipi(unsigned ipi,
+			      cpumask_t cpumask);
+
+#endif /* CONFIG_SMP */
+
+#define ipipe_sigwake_notify(p)	\
+do {					\
+	if (((p)->flags & PF_EVNOTIFY) && __ipipe_event_monitored_p(IPIPE_EVENT_SIGWAKE)) \
+		__ipipe_dispatch_event(IPIPE_EVENT_SIGWAKE,p);		\
+} while(0)
+
+#define ipipe_exit_notify(p)	\
+do {				\
+	if (((p)->flags & PF_EVNOTIFY) && __ipipe_event_monitored_p(IPIPE_EVENT_EXIT)) \
+		__ipipe_dispatch_event(IPIPE_EVENT_EXIT,p);		\
+} while(0)
+
+#define ipipe_setsched_notify(p)	\
+do {					\
+	if (((p)->flags & PF_EVNOTIFY) && __ipipe_event_monitored_p(IPIPE_EVENT_SETSCHED)) \
+		__ipipe_dispatch_event(IPIPE_EVENT_SETSCHED,p);		\
+} while(0)
+
+#define ipipe_schedule_notify(prev, next)				\
+do {									\
+	if ((((prev)->flags|(next)->flags) & PF_EVNOTIFY) &&		\
+	    __ipipe_event_monitored_p(IPIPE_EVENT_SCHEDULE))		\
+		__ipipe_dispatch_event(IPIPE_EVENT_SCHEDULE,next);	\
+} while(0)
+
+#define ipipe_trap_notify(ex, regs)		\
+({						\
+	int ret = 0;				\
+	if ((test_bit(IPIPE_NOSTACK_FLAG, &ipipe_this_cpudom_var(status)) || \
+	     ((current)->flags & PF_EVNOTIFY)) &&			\
+	    __ipipe_event_monitored_p(ex))				\
+		ret = __ipipe_dispatch_event(ex, regs);			\
+	ret;								\
+})
+
+static inline void ipipe_init_notify(struct task_struct *p)
+{
+	if (__ipipe_event_monitored_p(IPIPE_EVENT_INIT))
+		__ipipe_dispatch_event(IPIPE_EVENT_INIT,p);
+}
+
+struct mm_struct;
+
+static inline void ipipe_cleanup_notify(struct mm_struct *mm)
+{
+	if (__ipipe_event_monitored_p(IPIPE_EVENT_CLEANUP))
+		__ipipe_dispatch_event(IPIPE_EVENT_CLEANUP,mm);
+}
+
+/* Public interface */
+
+int ipipe_register_domain(struct ipipe_domain *ipd,
+			  struct ipipe_domain_attr *attr);
+
+int ipipe_unregister_domain(struct ipipe_domain *ipd);
+
+void ipipe_suspend_domain(void);
+
+int ipipe_virtualize_irq(struct ipipe_domain *ipd,
+			 unsigned irq,
+			 ipipe_irq_handler_t handler,
+			 void *cookie,
+			 ipipe_irq_ackfn_t acknowledge,
+			 unsigned modemask);
+
+int ipipe_control_irq(unsigned irq,
+		      unsigned clrmask,
+		      unsigned setmask);
+
+unsigned ipipe_alloc_virq(void);
+
+int ipipe_free_virq(unsigned virq);
+
+int ipipe_trigger_irq(unsigned irq);
+
+static inline void __ipipe_propagate_irq(unsigned irq)
+{
+	struct list_head *next = ipipe_current_domain->p_link.next;
+	if (next == &ipipe_root.p_link) {
+		/* Fast path: root must handle all interrupts. */
+		__ipipe_set_irq_pending(&ipipe_root, irq);
+		return;
+	}
+	__ipipe_pend_irq(irq, next);
+}
+
+static inline void __ipipe_schedule_irq(unsigned irq)
+{
+	__ipipe_pend_irq(irq, &ipipe_current_domain->p_link);
+}
+
+static inline void __ipipe_schedule_irq_head(unsigned irq)
+{
+	__ipipe_set_irq_pending(__ipipe_pipeline_head(), irq);
+}
+
+static inline void __ipipe_schedule_irq_root(unsigned irq)
+{
+	__ipipe_set_irq_pending(&ipipe_root, irq);
+}
+
+static inline void ipipe_propagate_irq(unsigned irq)
+{
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+	__ipipe_propagate_irq(irq);
+	local_irq_restore_hw(flags);
+}
+
+static inline void ipipe_schedule_irq(unsigned irq)
+{
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+	__ipipe_schedule_irq(irq);
+	local_irq_restore_hw(flags);
+}
+
+static inline void ipipe_schedule_irq_head(unsigned irq)
+{
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+	__ipipe_schedule_irq_head(irq);
+	local_irq_restore_hw(flags);
+}
+
+static inline void ipipe_schedule_irq_root(unsigned irq)
+{
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+	__ipipe_schedule_irq_root(irq);
+	local_irq_restore_hw(flags);
+}
+
+void ipipe_stall_pipeline_from(struct ipipe_domain *ipd);
+
+unsigned long ipipe_test_and_stall_pipeline_from(struct ipipe_domain *ipd);
+
+void ipipe_unstall_pipeline_from(struct ipipe_domain *ipd);
+
+unsigned long ipipe_test_and_unstall_pipeline_from(struct ipipe_domain *ipd);
+
+void ipipe_restore_pipeline_from(struct ipipe_domain *ipd,
+					  unsigned long x);
+
+static inline unsigned long ipipe_test_pipeline_from(struct ipipe_domain *ipd)
+{
+	return test_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipd, status));
+}
+
+static inline void ipipe_stall_pipeline_head(void)
+{
+	local_irq_disable_hw();
+	__set_bit(IPIPE_STALL_FLAG, &ipipe_head_cpudom_var(status));
+}
+
+static inline unsigned long ipipe_test_and_stall_pipeline_head(void)
+{
+	local_irq_disable_hw();
+	return __test_and_set_bit(IPIPE_STALL_FLAG, &ipipe_head_cpudom_var(status));
+}
+
+void ipipe_unstall_pipeline_head(void);
+
+void __ipipe_restore_pipeline_head(unsigned long x);
+
+static inline void ipipe_restore_pipeline_head(unsigned long x)
+{
+	/* On some archs, __test_and_set_bit() might return different
+	 * truth value than test_bit(), so we test the exclusive OR of
+	 * both statuses, assuming that the lowest bit is always set in
+	 * the truth value (if this is wrong, the failed optimization will
+	 * be caught in __ipipe_restore_pipeline_head() if
+	 * CONFIG_DEBUG_KERNEL is set). */
+	if ((x ^ test_bit(IPIPE_STALL_FLAG, &ipipe_head_cpudom_var(status))) & 1)
+		__ipipe_restore_pipeline_head(x);
+}
+
+#define ipipe_unstall_pipeline() \
+	ipipe_unstall_pipeline_from(ipipe_current_domain)
+
+#define ipipe_test_and_unstall_pipeline() \
+	ipipe_test_and_unstall_pipeline_from(ipipe_current_domain)
+
+#define ipipe_test_pipeline() \
+	ipipe_test_pipeline_from(ipipe_current_domain)
+
+#define ipipe_test_and_stall_pipeline() \
+	ipipe_test_and_stall_pipeline_from(ipipe_current_domain)
+
+#define ipipe_stall_pipeline() \
+	ipipe_stall_pipeline_from(ipipe_current_domain)
+
+#define ipipe_restore_pipeline(x) \
+	ipipe_restore_pipeline_from(ipipe_current_domain, (x))
+
+void ipipe_init_attr(struct ipipe_domain_attr *attr);
+
+int ipipe_get_sysinfo(struct ipipe_sysinfo *sysinfo);
+
+unsigned long ipipe_critical_enter(void (*syncfn) (void));
+
+void ipipe_critical_exit(unsigned long flags);
+
+static inline void ipipe_set_printk_sync(struct ipipe_domain *ipd)
+{
+	set_bit(IPIPE_SPRINTK_FLAG, &ipd->flags);
+}
+
+static inline void ipipe_set_printk_async(struct ipipe_domain *ipd)
+{
+	clear_bit(IPIPE_SPRINTK_FLAG, &ipd->flags);
+}
+
+static inline void ipipe_set_foreign_stack(struct ipipe_domain *ipd)
+{
+	/* Must be called hw interrupts off. */
+	__set_bit(IPIPE_NOSTACK_FLAG, &ipipe_cpudom_var(ipd, status));
+}
+
+static inline void ipipe_clear_foreign_stack(struct ipipe_domain *ipd)
+{
+	/* Must be called hw interrupts off. */
+	__clear_bit(IPIPE_NOSTACK_FLAG, &ipipe_cpudom_var(ipd, status));
+}
+
+#ifndef ipipe_safe_current
+#define ipipe_safe_current()					\
+({								\
+	struct task_struct *p;					\
+	p = test_bit(IPIPE_NOSTACK_FLAG,			\
+		     &ipipe_this_cpudom_var(status)) ? &init_task : current; \
+	p; \
+})
+#endif
+
+ipipe_event_handler_t ipipe_catch_event(struct ipipe_domain *ipd,
+					unsigned event,
+					ipipe_event_handler_t handler);
+
+cpumask_t ipipe_set_irq_affinity(unsigned irq,
+				 cpumask_t cpumask);
+
+int ipipe_send_ipi(unsigned ipi,
+			    cpumask_t cpumask);
+
+int ipipe_setscheduler_root(struct task_struct *p,
+			    int policy,
+			    int prio);
+
+int ipipe_reenter_root(struct task_struct *prev,
+		       int policy,
+		       int prio);
+
+int ipipe_alloc_ptdkey(void);
+
+int ipipe_free_ptdkey(int key);
+
+int ipipe_set_ptd(int key,
+			   void *value);
+
+void *ipipe_get_ptd(int key);
+
+int ipipe_disable_ondemand_mappings(struct task_struct *tsk);
+
+#define local_irq_enable_hw_cond()		local_irq_enable_hw()
+#define local_irq_disable_hw_cond()		local_irq_disable_hw()
+#define local_irq_save_hw_cond(flags)		local_irq_save_hw(flags)
+#define local_irq_restore_hw_cond(flags)	local_irq_restore_hw(flags)
+
+#define local_irq_enable_nohead(ipd)			\
+	do {						\
+		if (!__ipipe_pipeline_head_p(ipd))	\
+			local_irq_enable_hw();		\
+	} while(0)
+
+#define local_irq_disable_nohead(ipd)		\
+	do {						\
+		if (!__ipipe_pipeline_head_p(ipd))	\
+			local_irq_disable_hw();		\
+	} while(0)
+
+#define local_irq_save_full(vflags, rflags)		\
+	do {						\
+		local_irq_save(vflags);			\
+		local_irq_save_hw(rflags);		\
+	} while(0)
+
+#define local_irq_restore_full(vflags, rflags)		\
+	do {						\
+		local_irq_restore_hw(rflags);		\
+		local_irq_restore(vflags);		\
+	} while(0)
+
+static inline void local_irq_restore_nosync(unsigned long x)
+{
+	if (x)
+		set_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipipe_root_domain, status));
+	else
+		clear_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipipe_root_domain, status));
+}
+
+#define ipipe_root_domain_p		(ipipe_current_domain == ipipe_root_domain)
+
+static inline void ipipe_nmi_enter(void)
+{
+	int cpu = ipipe_processor_id();
+
+	per_cpu(ipipe_nmi_saved_root, cpu) = ipipe_root_cpudom_var(status);
+	__set_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status));
+
+#ifdef CONFIG_IPIPE_DEBUG_CONTEXT
+	per_cpu(ipipe_saved_context_check_state, cpu) =
+		ipipe_disable_context_check(cpu);
+#endif /* CONFIG_IPIPE_DEBUG_CONTEXT */
+}
+
+static inline void ipipe_nmi_exit(void)
+{
+	int cpu = ipipe_processor_id();
+
+#ifdef CONFIG_IPIPE_DEBUG_CONTEXT
+	ipipe_restore_context_check
+		(cpu, per_cpu(ipipe_saved_context_check_state, cpu));
+#endif /* CONFIG_IPIPE_DEBUG_CONTEXT */
+
+	if (!test_bit(IPIPE_STALL_FLAG, &per_cpu(ipipe_nmi_saved_root, cpu)))
+		__clear_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status));
+}
+
+#else	/* !CONFIG_IPIPE */
+
+#define ipipe_init()			do { } while(0)
+#define ipipe_suspend_domain()		do { } while(0)
+#define ipipe_sigwake_notify(p)		do { } while(0)
+#define ipipe_setsched_notify(p)	do { } while(0)
+#define ipipe_init_notify(p)		do { } while(0)
+#define ipipe_exit_notify(p)		do { } while(0)
+#define ipipe_cleanup_notify(mm)	do { } while(0)
+#define ipipe_trap_notify(t,r)		0
+#define ipipe_init_proc()		do { } while(0)
+
+static inline void __ipipe_pin_range_globally(unsigned long start,
+					      unsigned long end)
+{
+}
+
+#define local_irq_enable_hw_cond()		do { } while(0)
+#define local_irq_disable_hw_cond()		do { } while(0)
+#define local_irq_save_hw_cond(flags)		do { (void)(flags); } while(0)
+#define local_irq_restore_hw_cond(flags)	do { } while(0)
+
+#define ipipe_irq_lock(irq)		do { } while(0)
+#define ipipe_irq_unlock(irq)		do { } while(0)
+
+#define ipipe_root_domain_p		1
+#define ipipe_safe_current		current
+#define ipipe_processor_id()		smp_processor_id()
+
+#define ipipe_nmi_enter()		do { } while (0)
+#define ipipe_nmi_exit()		do { } while (0)
+
+#define local_irq_disable_head()	local_irq_disable()
+
+#define local_irq_save_full(vflags, rflags)	do { (void)(vflags); local_irq_save(rflags); } while(0)
+#define local_irq_restore_full(vflags, rflags)	do { (void)(vflags); local_irq_restore(rflags); } while(0)
+#define local_irq_restore_nosync(vflags)	local_irq_restore(vflags)
+
+#endif	/* CONFIG_IPIPE */
+
+#endif	/* !__LINUX_IPIPE_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/ipipe_base.h b/include/linux/ipipe_base.h
new file mode 100644
index 0000000..c49fe14
--- /dev/null
+++ b/include/linux/ipipe_base.h
@@ -0,0 +1,90 @@
+/* -*- linux-c -*-
+ * include/linux/ipipe_base.h
+ *
+ * Copyright (C) 2002-2007 Philippe Gerum.
+ *               2007 Jan Kiszka.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __LINUX_IPIPE_BASE_H
+#define __LINUX_IPIPE_BASE_H
+
+#ifdef CONFIG_IPIPE
+
+#include <linux/bitops.h>
+#include <asm/ipipe_base.h>
+
+/* Number of virtual IRQs */
+#define IPIPE_NR_VIRQS		BITS_PER_LONG
+/* First virtual IRQ # */
+#define IPIPE_VIRQ_BASE		(((IPIPE_NR_XIRQS + BITS_PER_LONG - 1) / BITS_PER_LONG) * BITS_PER_LONG)
+/* Total number of IRQ slots */
+#define IPIPE_NR_IRQS		(IPIPE_VIRQ_BASE + IPIPE_NR_VIRQS)
+/* Number of indirect words needed to map the whole IRQ space. */
+#define IPIPE_IRQ_IWORDS	((IPIPE_NR_IRQS + BITS_PER_LONG - 1) / BITS_PER_LONG)
+#define IPIPE_IRQ_IMASK		(BITS_PER_LONG - 1)
+#define IPIPE_IRQMASK_ANY	(~0L)
+#define IPIPE_IRQMASK_VIRT	(IPIPE_IRQMASK_ANY << (IPIPE_VIRQ_BASE / BITS_PER_LONG))
+
+/* Per-cpu pipeline status */
+#define IPIPE_STALL_FLAG	0	/* Stalls a pipeline stage -- guaranteed at bit #0 */
+#define IPIPE_SYNC_FLAG		1	/* The interrupt syncer is running for the domain */
+#define IPIPE_NOSTACK_FLAG	2	/* Domain currently runs on a foreign stack */
+
+#define IPIPE_STALL_MASK	(1L << IPIPE_STALL_FLAG)
+#define IPIPE_SYNC_MASK		(1L << IPIPE_SYNC_FLAG)
+#define IPIPE_NOSTACK_MASK	(1L << IPIPE_NOSTACK_FLAG)
+
+typedef void (*ipipe_irq_handler_t)(unsigned irq,
+				    void *cookie);
+
+extern struct ipipe_domain ipipe_root;
+
+#define ipipe_root_domain (&ipipe_root)
+
+void __ipipe_unstall_root(void);
+
+void __ipipe_restore_root(unsigned long x);
+
+#define ipipe_preempt_disable(flags)	local_irq_save_hw(flags)
+#define ipipe_preempt_enable(flags)	local_irq_restore_hw(flags)
+ 
+#ifdef CONFIG_IPIPE_DEBUG_CONTEXT
+void ipipe_check_context(struct ipipe_domain *border_ipd);
+#else /* !CONFIG_IPIPE_DEBUG_CONTEXT */
+static inline void ipipe_check_context(struct ipipe_domain *border_ipd) { }
+#endif /* !CONFIG_IPIPE_DEBUG_CONTEXT */
+
+/* Generic features */
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+#define __IPIPE_FEATURE_REQUEST_TICKDEV    1
+#endif
+#define __IPIPE_FEATURE_DELAYED_ATOMICSW   1
+#define __IPIPE_FEATURE_FASTPEND_IRQ       1
+#define __IPIPE_FEATURE_TRACE_EVENT	   1
+
+#else /* !CONFIG_IPIPE */
+#define ipipe_preempt_disable(flags)	do { \
+						preempt_disable(); \
+						(void)(flags); \
+					} while (0)
+#define ipipe_preempt_enable(flags)	preempt_enable()
+#define ipipe_check_context(ipd)	do { } while(0)
+#endif	/* CONFIG_IPIPE */
+
+#endif	/* !__LINUX_IPIPE_BASE_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/ipipe_compat.h b/include/linux/ipipe_compat.h
new file mode 100644
index 0000000..50a245c
--- /dev/null
+++ b/include/linux/ipipe_compat.h
@@ -0,0 +1,54 @@
+/* -*- linux-c -*-
+ * include/linux/ipipe_compat.h
+ *
+ * Copyright (C) 2007 Philippe Gerum.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __LINUX_IPIPE_COMPAT_H
+#define __LINUX_IPIPE_COMPAT_H
+
+#ifdef CONFIG_IPIPE_COMPAT
+/*
+ * OBSOLETE: defined only for backward compatibility. Will be removed
+ * in future releases, please update client code accordingly.
+ */
+
+#ifdef CONFIG_SMP
+#define ipipe_declare_cpuid	int cpuid
+#define ipipe_load_cpuid()	do { \
+					cpuid = ipipe_processor_id();	\
+				} while(0)
+#define ipipe_lock_cpu(flags)	do { \
+					local_irq_save_hw(flags); \
+					cpuid = ipipe_processor_id(); \
+				} while(0)
+#define ipipe_unlock_cpu(flags)	local_irq_restore_hw(flags)
+#define ipipe_get_cpu(flags)	ipipe_lock_cpu(flags)
+#define ipipe_put_cpu(flags)	ipipe_unlock_cpu(flags)
+#else /* !CONFIG_SMP */
+#define ipipe_declare_cpuid	const int cpuid = 0
+#define ipipe_load_cpuid()	do { } while(0)
+#define ipipe_lock_cpu(flags)	local_irq_save_hw(flags)
+#define ipipe_unlock_cpu(flags)	local_irq_restore_hw(flags)
+#define ipipe_get_cpu(flags)	do { (void)(flags); } while(0)
+#define ipipe_put_cpu(flags)	do { } while(0)
+#endif /* CONFIG_SMP */
+
+#endif /* CONFIG_IPIPE_COMPAT */
+
+#endif	/* !__LINUX_IPIPE_COMPAT_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/ipipe_percpu.h b/include/linux/ipipe_percpu.h
new file mode 100644
index 0000000..2f41af3
--- /dev/null
+++ b/include/linux/ipipe_percpu.h
@@ -0,0 +1,84 @@
+/*   -*- linux-c -*-
+ *   include/linux/ipipe_percpu.h
+ *
+ *   Copyright (C) 2007 Philippe Gerum.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ *   USA; either version 2 of the License, or (at your option) any later
+ *   version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __LINUX_IPIPE_PERCPU_H
+#define __LINUX_IPIPE_PERCPU_H
+
+#include <asm/percpu.h>
+#include <asm/ptrace.h>
+
+struct ipipe_domain;
+
+struct ipipe_percpu_domain_data {
+	unsigned long status;	/* <= Must be first in struct. */
+	unsigned long irqpend_himask;
+	unsigned long irqpend_lomask[IPIPE_IRQ_IWORDS];
+	unsigned long irqheld_mask[IPIPE_IRQ_IWORDS];
+	unsigned long irqall[IPIPE_NR_IRQS];
+	u64 evsync;
+};
+
+#ifdef CONFIG_SMP
+#define ipipe_percpudom_ptr(ipd, cpu)	\
+	(&per_cpu(ipipe_percpu_darray, cpu)[(ipd)->slot])
+#define ipipe_cpudom_ptr(ipd)	\
+	(&__raw_get_cpu_var(ipipe_percpu_darray)[(ipd)->slot])
+#else
+DECLARE_PER_CPU(struct ipipe_percpu_domain_data *, ipipe_percpu_daddr[CONFIG_IPIPE_DOMAINS]);
+#define ipipe_percpudom_ptr(ipd, cpu)	\
+	(per_cpu(ipipe_percpu_daddr, cpu)[(ipd)->slot])
+#define ipipe_cpudom_ptr(ipd)	\
+	(__raw_get_cpu_var(ipipe_percpu_daddr)[(ipd)->slot])
+#endif
+#define ipipe_percpudom(ipd, var, cpu)	(ipipe_percpudom_ptr(ipd, cpu)->var)
+#define ipipe_cpudom_var(ipd, var)	(ipipe_cpudom_ptr(ipd)->var)
+
+#define IPIPE_ROOT_SLOT			0
+#define IPIPE_HEAD_SLOT			(CONFIG_IPIPE_DOMAINS - 1)
+
+DECLARE_PER_CPU(struct ipipe_percpu_domain_data, ipipe_percpu_darray[CONFIG_IPIPE_DOMAINS]);
+
+DECLARE_PER_CPU(struct ipipe_domain *, ipipe_percpu_domain);
+
+DECLARE_PER_CPU(unsigned long, ipipe_nmi_saved_root);
+
+#ifdef CONFIG_IPIPE_DEBUG_CONTEXT
+DECLARE_PER_CPU(int, ipipe_percpu_context_check);
+DECLARE_PER_CPU(int, ipipe_saved_context_check_state);
+#endif
+
+#define ipipe_percpu(var, cpu)		per_cpu(var, cpu)
+#define ipipe_cpu_var(var)		__raw_get_cpu_var(var)
+
+#define ipipe_root_cpudom_ptr(var)	\
+	(&__raw_get_cpu_var(ipipe_percpu_darray)[IPIPE_ROOT_SLOT])
+
+#define ipipe_root_cpudom_var(var)	ipipe_root_cpudom_ptr()->var
+
+#define ipipe_this_cpudom_var(var)	\
+	ipipe_cpudom_var(ipipe_current_domain, var)
+
+#define ipipe_head_cpudom_ptr()		\
+	(&__raw_get_cpu_var(ipipe_percpu_darray)[IPIPE_HEAD_SLOT])
+
+#define ipipe_head_cpudom_var(var)	ipipe_head_cpudom_ptr()->var
+
+#endif	/* !__LINUX_IPIPE_PERCPU_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/ipipe_tickdev.h b/include/linux/ipipe_tickdev.h
new file mode 100644
index 0000000..4a1cb1b
--- /dev/null
+++ b/include/linux/ipipe_tickdev.h
@@ -0,0 +1,58 @@
+/* -*- linux-c -*-
+ * include/linux/ipipe_tickdev.h
+ *
+ * Copyright (C) 2007 Philippe Gerum.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __LINUX_IPIPE_TICKDEV_H
+#define __LINUX_IPIPE_TICKDEV_H
+
+#if defined(CONFIG_IPIPE) && defined(CONFIG_GENERIC_CLOCKEVENTS)
+
+#include <linux/clockchips.h>
+
+struct tick_device;
+
+struct ipipe_tick_device {
+
+	void (*emul_set_mode)(enum clock_event_mode,
+			      struct clock_event_device *cdev);
+	int (*emul_set_tick)(unsigned long delta,
+			     struct clock_event_device *cdev);
+	void (*real_set_mode)(enum clock_event_mode mode,
+			      struct clock_event_device *cdev);
+	int (*real_set_tick)(unsigned long delta,
+			     struct clock_event_device *cdev);
+	struct tick_device *slave;
+	unsigned long real_max_delta_ns;
+	unsigned long real_mult;
+	int real_shift;
+};
+
+int ipipe_request_tickdev(const char *devname,
+			  void (*emumode)(enum clock_event_mode mode,
+					  struct clock_event_device *cdev),
+			  int (*emutick)(unsigned long evt,
+					 struct clock_event_device *cdev),
+			  int cpu, unsigned long *tmfreq);
+
+void ipipe_release_tickdev(int cpu);
+
+#endif /* CONFIG_IPIPE && CONFIG_GENERIC_CLOCKEVENTS */
+
+#endif /* !__LINUX_IPIPE_TICKDEV_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/ipipe_trace.h b/include/linux/ipipe_trace.h
new file mode 100644
index 0000000..627b354
--- /dev/null
+++ b/include/linux/ipipe_trace.h
@@ -0,0 +1,72 @@
+/* -*- linux-c -*-
+ * include/linux/ipipe_trace.h
+ *
+ * Copyright (C) 2005 Luotao Fu.
+ *               2005-2007 Jan Kiszka.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _LINUX_IPIPE_TRACE_H
+#define _LINUX_IPIPE_TRACE_H
+
+#ifdef CONFIG_IPIPE_TRACE
+
+#include <linux/types.h>
+
+void ipipe_trace_begin(unsigned long v);
+void ipipe_trace_end(unsigned long v);
+void ipipe_trace_freeze(unsigned long v);
+void ipipe_trace_special(unsigned char special_id, unsigned long v);
+void ipipe_trace_pid(pid_t pid, short prio);
+void ipipe_trace_event(unsigned char id, unsigned long delay_tsc);
+int ipipe_trace_max_reset(void);
+int ipipe_trace_frozen_reset(void);
+
+#else /* !CONFIG_IPIPE_TRACE */
+
+#define ipipe_trace_begin(v)			do { (void)(v); } while(0)
+#define ipipe_trace_end(v)			do { (void)(v); } while(0)
+#define ipipe_trace_freeze(v)			do { (void)(v); } while(0)
+#define ipipe_trace_special(id, v)		do { (void)(id); (void)(v); } while(0)
+#define ipipe_trace_pid(pid, prio)		do { (void)(pid); (void)(prio); } while(0)
+#define ipipe_trace_event(id, delay_tsc)	do { (void)(id); (void)(delay_tsc); } while(0)
+#define ipipe_trace_max_reset()			do { } while(0)
+#define ipipe_trace_froze_reset()		do { } while(0)
+
+#endif /* !CONFIG_IPIPE_TRACE */
+
+#ifdef CONFIG_IPIPE_TRACE_PANIC
+void ipipe_trace_panic_freeze(void);
+void ipipe_trace_panic_dump(void);
+#else
+static inline void ipipe_trace_panic_freeze(void) { }
+static inline void ipipe_trace_panic_dump(void) { }
+#endif
+
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+#define ipipe_trace_irq_entry(irq)	ipipe_trace_begin(irq)
+#define ipipe_trace_irq_exit(irq)	ipipe_trace_end(irq)
+#define ipipe_trace_irqsoff()		ipipe_trace_begin(0x80000000UL)
+#define ipipe_trace_irqson()		ipipe_trace_end(0x80000000UL)
+#else
+#define ipipe_trace_irq_entry(irq)	do { (void)(irq);} while(0)
+#define ipipe_trace_irq_exit(irq)	do { (void)(irq);} while(0)
+#define ipipe_trace_irqsoff()		do { } while(0)
+#define ipipe_trace_irqson()		do { } while(0)
+#endif
+
+#endif	/* !__LINUX_IPIPE_TRACE_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/irq.h b/include/linux/irq.h
index 3dddfa7..5e1f95c 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -114,6 +114,9 @@ struct irq_chip {
 
 	void		(*end)(unsigned int irq);
 	void		(*set_affinity)(unsigned int irq, cpumask_t dest);
+#ifdef CONFIG_IPIPE
+	void		(*move)(unsigned int irq);
+#endif /* CONFIG_IPIPE */
 	int		(*retrigger)(unsigned int irq);
 	int		(*set_type)(unsigned int irq, unsigned int flow_type);
 	int		(*set_wake)(unsigned int irq, unsigned int on);
@@ -153,6 +156,13 @@ struct irq_chip {
  * @name:		flow handler name for /proc/interrupts output
  */
 struct irq_desc {
+#ifdef CONFIG_IPIPE
+	void			(*ipipe_ack)(unsigned int irq,
+					     struct irq_desc *desc);
+	void			(*ipipe_end)(unsigned int irq,
+					     struct irq_desc *desc);
+	int                     ic_prio;
+#endif /* CONFIG_IPIPE */
 	unsigned int		irq;
 	irq_flow_handler_t	handle_irq;
 	struct irq_chip		*chip;
@@ -315,6 +325,10 @@ set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 			      irq_flow_handler_t handle, const char *name);
 
 extern void
+___set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
+		   const char *name);
+
+extern void
 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 		  const char *name);
 
@@ -338,6 +352,15 @@ set_irq_handler(unsigned int irq, irq_flow_handler_t handle)
 }
 
 /*
+ * Same, but without holding the descriptor lock.
+ */
+static inline void
+_set_irq_handler(unsigned int irq, irq_flow_handler_t handle)
+{
+	___set_irq_handler(irq, handle, 0, NULL);
+}
+
+/*
  * Set a highlevel chained flow handler for a given IRQ.
  * (a chained handler is automatically enabled and set to
  *  IRQ_NOREQUEST and IRQ_NOPROBE)
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/kernel.h b/include/linux/kernel.h
index dc7e0d0..88d5034 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -14,6 +14,7 @@
 #include <linux/compiler.h>
 #include <linux/bitops.h>
 #include <linux/log2.h>
+#include <linux/ipipe_base.h>
 #include <linux/typecheck.h>
 #include <linux/ratelimit.h>
 #include <linux/dynamic_printk.h>
@@ -111,9 +112,12 @@ struct user;
 
 #ifdef CONFIG_PREEMPT_VOLUNTARY
 extern int _cond_resched(void);
-# define might_resched() _cond_resched()
+# define might_resched() do { \
+		ipipe_check_context(ipipe_root_domain); \
+		_cond_resched(); \
+	} while (0)
 #else
-# define might_resched() do { } while (0)
+# define might_resched() ipipe_check_context(ipipe_root_domain)
 #endif
 
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/linkage.h b/include/linux/linkage.h
index 9fd1f85..8018d53 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -93,4 +93,8 @@
 #define ATTRIB_NORET  __attribute__((noreturn))
 #define NORET_AND     noreturn,
 
+#ifndef notrace
+#define notrace		__attribute__((no_instrument_function))
+#endif
+
 #endif
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/mm.h b/include/linux/mm.h
index 69a4c38..a780885 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -116,6 +116,8 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_MIXEDMAP	0x10000000	/* Can contain "struct page" and pure PFN pages */
 #define VM_SAO		0x20000000	/* Strong Access Ordering (powerpc) */
 
+#define VM_PINNED	0x40000000	/* Disable faults for the vma */
+
 #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
 #endif
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/preempt.h b/include/linux/preempt.h
index 72b1a10..80553be 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -9,13 +9,20 @@
 #include <linux/thread_info.h>
 #include <linux/linkage.h>
 #include <linux/list.h>
+#include <linux/ipipe_base.h>
 
 #if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
   extern void add_preempt_count(int val);
   extern void sub_preempt_count(int val);
 #else
-# define add_preempt_count(val)	do { preempt_count() += (val); } while (0)
-# define sub_preempt_count(val)	do { preempt_count() -= (val); } while (0)
+# define add_preempt_count(val)	do {		\
+    ipipe_check_context(ipipe_root_domain);	\
+    preempt_count() += (val);			\
+  } while (0)
+# define sub_preempt_count(val)	do {		\
+    ipipe_check_context(ipipe_root_domain);	\
+    preempt_count() -= (val);			\
+  } while (0)
 #endif
 
 #define inc_preempt_count() add_preempt_count(1)
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/sched.h b/include/linux/sched.h
index 3883c32..7a30b68 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -59,6 +59,7 @@ struct sched_param {
 #include <linux/errno.h>
 #include <linux/nodemask.h>
 #include <linux/mm_types.h>
+#include <linux/ipipe.h>
 
 #include <asm/system.h>
 #include <asm/page.h>
@@ -181,6 +182,13 @@ extern unsigned long long time_sync_thresh;
 /* in tsk->state again */
 #define TASK_DEAD		64
 #define TASK_WAKEKILL		128
+#ifdef CONFIG_IPIPE
+#define TASK_ATOMICSWITCH	512
+#define TASK_NOWAKEUP		1024
+#else  /* !CONFIG_IPIPE */
+#define TASK_ATOMICSWITCH	0
+#define TASK_NOWAKEUP		0
+#endif /* CONFIG_IPIPE */
 
 /* Convenience macros for the sake of set_task_state */
 #define TASK_KILLABLE		(TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
@@ -289,6 +297,15 @@ extern void account_process_tick(struct task_struct *task, int user);
 extern void update_process_times(int user);
 extern void scheduler_tick(void);
 
+#ifdef CONFIG_IPIPE
+extern void update_root_process_times(struct pt_regs *regs);
+#else  /* !CONFIG_IPIPE */
+static inline void update_root_process_times(struct pt_regs *regs)
+{
+	update_process_times(user_mode(regs));
+}
+#endif /* CONFIG_IPIPE */
+
 extern void sched_show_task(struct task_struct *p);
 
 #ifdef CONFIG_DETECT_SOFTLOCKUP
@@ -1331,6 +1348,9 @@ struct task_struct {
 #endif
 	atomic_t fs_excl;	/* holding fs exclusive resources */
 	struct rcu_head rcu;
+#ifdef CONFIG_IPIPE
+	void *ptd[IPIPE_ROOT_NPTDKEYS];
+#endif
 
 	/*
 	 * cache last used pipe for splice
@@ -1542,6 +1562,11 @@ extern cputime_t task_gtime(struct task_struct *p);
 #define PF_EXITING	0x00000004	/* getting shut down */
 #define PF_EXITPIDONE	0x00000008	/* pi exit done on shut down */
 #define PF_VCPU		0x00000010	/* I'm a virtual CPU */
+#ifdef CONFIG_IPIPE
+#define PF_EVNOTIFY	0x00000020	/* Notify other domains about internal events */
+#else
+#define PF_EVNOTIFY	0
+#endif /* CONFIG_IPIPE */
 #define PF_FORKNOEXEC	0x00000040	/* forked but didn't exec */
 #define PF_SUPERPRIV	0x00000100	/* used super-user privileges */
 #define PF_DUMPCORE	0x00000200	/* dumped core */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/spinlock.h b/include/linux/spinlock.h
index e0c0fcc..2044388 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -90,10 +90,14 @@ extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
 # include <linux/spinlock_up.h>
 #endif
 
+#undef TYPE_EQUAL
+#define TYPE_EQUAL(lock, type) \
+	__builtin_types_compatible_p(typeof(lock), type *)
+
 #ifdef CONFIG_DEBUG_SPINLOCK
   extern void __spin_lock_init(spinlock_t *lock, const char *name,
 			       struct lock_class_key *key);
-# define spin_lock_init(lock)					\
+# define _spin_lock_init(lock)				\
 do {								\
 	static struct lock_class_key __key;			\
 								\
@@ -101,10 +105,21 @@ do {								\
 } while (0)
 
 #else
-# define spin_lock_init(lock)					\
+# define _spin_lock_init(lock)				\
 	do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
 #endif
 
+# define spin_lock_init(lock)						\
+	do {								\
+		if (TYPE_EQUAL((lock), __ipipe_spinlock_t))		\
+			do {						\
+				IPIPE_DEFINE_SPINLOCK(__lock__);	\
+				*((ipipe_spinlock_t *)lock) = __lock__; \
+			} while(0);					\
+		else							\
+			_spin_lock_init((spinlock_t *)lock);		\
+	} while(0)
+
 #ifdef CONFIG_DEBUG_SPINLOCK
   extern void __rwlock_init(rwlock_t *lock, const char *name,
 			    struct lock_class_key *key);
@@ -179,7 +194,94 @@ do {								\
 #define read_trylock(lock)		__cond_lock(lock, _read_trylock(lock))
 #define write_trylock(lock)		__cond_lock(lock, _write_trylock(lock))
 
-#define spin_lock(lock)			_spin_lock(lock)
+#define PICK_SPINOP(op, lock)						\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t))			\
+		__raw_spin##op(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	else if (TYPE_EQUAL(lock, spinlock_t))				\
+		_spin##op((spinlock_t *)(lock));			\
+} while (0)
+
+#define PICK_SPINOP_RAW(op, lock)					\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t))			\
+		__raw_spin##op(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	else if (TYPE_EQUAL(lock, spinlock_t))				\
+		__raw_spin##op(&((spinlock_t *)(lock))->raw_lock);	\
+} while (0)
+
+#define PICK_SPINLOCK_IRQ(lock)						\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		__ipipe_spin_lock_irq(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		_spin_lock_irq((spinlock_t *)(lock));			\
+} while (0)
+
+#define PICK_SPINUNLOCK_IRQ(lock)					\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		__ipipe_spin_unlock_irq(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		_spin_unlock_irq((spinlock_t *)(lock));			\
+} while (0)
+
+#define PICK_SPINLOCK_IRQ_RAW(lock)					\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		__ipipe_spin_lock_irq(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		local_irq_disable();					\
+		__raw_spin_lock(&((spinlock_t *)(lock))->raw_lock);	\
+} while (0)
+
+#define PICK_SPINUNLOCK_IRQ_RAW(lock)					\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		__ipipe_spin_unlock_irq(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		__raw_spin_unlock(&((spinlock_t *)(lock))->raw_lock);	\
+		local_irq_enable();					\
+} while (0)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+extern int __bad_spinlock_type(void);
+
+#define PICK_SPINLOCK_IRQSAVE(lock, flags)				\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		(flags) = __ipipe_spin_lock_irqsave(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		flags = _spin_lock_irqsave((spinlock_t *)(lock));	\
+	else __bad_spinlock_type();					\
+} while (0)
+#define PICK_SPINLOCK_IRQSAVE_NESTED(lock, flags, subclass)		\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		(flags) = __ipipe_spin_lock_irqsave(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		flags = _spin_lock_irqsave_nested((spinlock_t *)(lock), subclass); \
+	else __bad_spinlock_type();					\
+} while (0)
+#else
+#define PICK_SPINLOCK_IRQSAVE(lock, flags)				\
+do {									\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		(flags) = __ipipe_spin_lock_irqsave(&((__ipipe_spinlock_t *)(lock))->__raw_lock); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		_spin_lock_irqsave((spinlock_t *)(lock), flags);	\
+} while (0)
+#endif
+
+#define PICK_SPINUNLOCK_IRQRESTORE(lock, flags)				\
+	do {								\
+	if (TYPE_EQUAL((lock), __ipipe_spinlock_t)) {			\
+		__ipipe_spin_unlock_irqrestore(&((__ipipe_spinlock_t *)(lock))->__raw_lock, flags); \
+	} else if (TYPE_EQUAL(lock, spinlock_t))			\
+		_spin_unlock_irqrestore((spinlock_t *)(lock), flags);	\
+} while (0)
+
+#define spin_lock(lock)	PICK_SPINOP(_lock, lock)
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
@@ -201,7 +303,7 @@ do {								\
 #define spin_lock_irqsave(lock, flags)			\
 	do {						\
 		typecheck(unsigned long, flags);	\
-		flags = _spin_lock_irqsave(lock);	\
+		PICK_SPINLOCK_IRQSAVE(lock, flags);	\
 	} while (0)
 #define read_lock_irqsave(lock, flags)			\
 	do {						\
@@ -218,13 +320,13 @@ do {								\
 #define spin_lock_irqsave_nested(lock, flags, subclass)			\
 	do {								\
 		typecheck(unsigned long, flags);			\
-		flags = _spin_lock_irqsave_nested(lock, subclass);	\
+		PICK_SPINLOCK_IRQSAVE_NESTED(lock, flags, subclass);	\
 	} while (0)
 #else
 #define spin_lock_irqsave_nested(lock, flags, subclass)			\
 	do {								\
 		typecheck(unsigned long, flags);			\
-		flags = _spin_lock_irqsave(lock);			\
+		PICK_SPINLOCK_IRQSAVE(lock, flags);			\
 	} while (0)
 #endif
 
@@ -233,7 +335,7 @@ do {								\
 #define spin_lock_irqsave(lock, flags)			\
 	do {						\
 		typecheck(unsigned long, flags);	\
-		_spin_lock_irqsave(lock, flags);	\
+		PICK_SPINLOCK_IRQSAVE(lock, flags);	\
 	} while (0)
 #define read_lock_irqsave(lock, flags)			\
 	do {						\
@@ -250,7 +352,7 @@ do {								\
 
 #endif
 
-#define spin_lock_irq(lock)		_spin_lock_irq(lock)
+#define spin_lock_irq(lock)		PICK_SPINLOCK_IRQ(lock)
 #define spin_lock_bh(lock)		_spin_lock_bh(lock)
 
 #define read_lock_irq(lock)		_read_lock_irq(lock)
@@ -264,32 +366,40 @@ do {								\
  */
 #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
 	!defined(CONFIG_SMP)
-# define spin_unlock(lock)		_spin_unlock(lock)
+#define spin_unlock(lock)		PICK_SPINOP(_unlock, lock)
 # define read_unlock(lock)		_read_unlock(lock)
 # define write_unlock(lock)		_write_unlock(lock)
-# define spin_unlock_irq(lock)		_spin_unlock_irq(lock)
-# define read_unlock_irq(lock)		_read_unlock_irq(lock)
-# define write_unlock_irq(lock)		_write_unlock_irq(lock)
+# define spin_unlock_irq(lock)	PICK_SPINUNLOCK_IRQ(lock)
+# define read_unlock_irq(lock)	_read_unlock_irq(lock)
+# define write_unlock_irq(lock)	_write_unlock_irq(lock)
 #else
-# define spin_unlock(lock) \
-    do {__raw_spin_unlock(&(lock)->raw_lock); __release(lock); } while (0)
-# define read_unlock(lock) \
-    do {__raw_read_unlock(&(lock)->raw_lock); __release(lock); } while (0)
-# define write_unlock(lock) \
-    do {__raw_write_unlock(&(lock)->raw_lock); __release(lock); } while (0)
-# define spin_unlock_irq(lock)			\
+# define spin_unlock(lock)			\
 do {						\
-	__raw_spin_unlock(&(lock)->raw_lock);	\
+	PICK_SPINOP_RAW(_unlock, lock); 	\
+	__release(lock);			\
+} while(0)
+# define read_unlock(lock)			\
+do {						\
+	__raw_read_unlock(&(lock)->raw_lock);	\
 	__release(lock);			\
-	local_irq_enable();			\
 } while (0)
-# define read_unlock_irq(lock)			\
+# define write_unlock(lock)			\
+do {						\
+	__raw_write_unlock(&(lock)->raw_lock);	\
+	__release(lock);			\
+} while (0)
+# define spin_unlock_irq(lock)		\
+do {						\
+	PICK_SPINUNLOCK_IRQ_RAW(lock);		\
+	__release(lock);			\
+} while(0)
+# define read_unlock_irq(lock)		\
 do {						\
 	__raw_read_unlock(&(lock)->raw_lock);	\
 	__release(lock);			\
 	local_irq_enable();			\
 } while (0)
-# define write_unlock_irq(lock)			\
+# define write_unlock_irq(lock)		\
 do {						\
 	__raw_write_unlock(&(lock)->raw_lock);	\
 	__release(lock);			\
@@ -300,7 +410,7 @@ do {						\
 #define spin_unlock_irqrestore(lock, flags)		\
 	do {						\
 		typecheck(unsigned long, flags);	\
-		_spin_unlock_irqrestore(lock, flags);	\
+		PICK_SPINUNLOCK_IRQRESTORE(lock, flags);	\
 	} while (0)
 #define spin_unlock_bh(lock)		_spin_unlock_bh(lock)
 
@@ -364,4 +474,29 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
  */
 #define spin_can_lock(lock)	(!spin_is_locked(lock))
 
+#ifdef CONFIG_IPIPE
+void __ipipe_spin_lock_irq(raw_spinlock_t *lock);
+void __ipipe_spin_unlock_irq(raw_spinlock_t *lock);
+unsigned long __ipipe_spin_lock_irqsave(raw_spinlock_t *lock);
+void __ipipe_spin_unlock_irqrestore(raw_spinlock_t *lock,
+					     unsigned long x);
+void __ipipe_spin_unlock_irqbegin(ipipe_spinlock_t *lock);
+void __ipipe_spin_unlock_irqcomplete(unsigned long x);
+#define spin_lock_irqsave_cond(lock, flags) \
+	spin_lock_irqsave(lock, flags)
+#define spin_unlock_irqrestore_cond(lock, flags) \
+	spin_unlock_irqrestore(lock, flags)
+#else
+#define spin_lock_irqsave_cond(lock, flags) \
+	do { (void)(flags); spin_lock(lock); } while(0)
+#define spin_unlock_irqrestore_cond(lock, flags) \
+	spin_unlock(lock)
+#define __ipipe_spin_lock_irq(lock)		do { } while(0)
+#define __ipipe_spin_unlock_irq(lock)		do { } while(0)
+#define __ipipe_spin_lock_irqsave(lock)		0
+#define __ipipe_spin_unlock_irqrestore(lock, x)	do { (void)(x); } while(0)
+#define __ipipe_spin_unlock_irqbegin(lock)	do { } while(0)
+#define __ipipe_spin_unlock_irqcomplete(x)	do { (void)(x); } while(0)
+#endif
+
 #endif /* __LINUX_SPINLOCK_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index 68d88f7..f5ce3c4 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/include/linux/spinlock_types.h
+++ b/include/linux/spinlock_types.h
@@ -31,6 +31,10 @@ typedef struct {
 #endif
 } spinlock_t;
 
+typedef struct {
+	raw_spinlock_t __raw_lock;
+} __ipipe_spinlock_t;
+
 #define SPINLOCK_MAGIC		0xdead4ead
 
 typedef struct {
@@ -92,9 +96,21 @@ typedef struct {
  * __SPIN_LOCK_UNLOCKED()/__RW_LOCK_UNLOCKED() as appropriate.
  */
 #define SPIN_LOCK_UNLOCKED	__SPIN_LOCK_UNLOCKED(old_style_spin_init)
+#define IPIPE_SPIN_LOCK_UNLOCKED					\
+	(__ipipe_spinlock_t) {	.__raw_lock = __RAW_SPIN_LOCK_UNLOCKED }
 #define RW_LOCK_UNLOCKED	__RW_LOCK_UNLOCKED(old_style_rw_init)
 
 #define DEFINE_SPINLOCK(x)	spinlock_t x = __SPIN_LOCK_UNLOCKED(x)
 #define DEFINE_RWLOCK(x)	rwlock_t x = __RW_LOCK_UNLOCKED(x)
 
+#ifdef CONFIG_IPIPE
+# define ipipe_spinlock_t		__ipipe_spinlock_t
+# define IPIPE_DEFINE_SPINLOCK(x)	ipipe_spinlock_t x = IPIPE_SPIN_LOCK_UNLOCKED
+# define IPIPE_DECLARE_SPINLOCK(x)	extern ipipe_spinlock_t x
+#else
+# define ipipe_spinlock_t		spinlock_t
+# define IPIPE_DEFINE_SPINLOCK(x)	DEFINE_SPINLOCK(x)
+# define IPIPE_DECLARE_SPINLOCK(x)	extern spinlock_t x
+#endif
+
 #endif /* __LINUX_SPINLOCK_TYPES_H */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/init/Kconfig b/init/Kconfig
index f763762..06af92d 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/init/Kconfig
+++ b/init/Kconfig
@@ -73,6 +73,7 @@ config INIT_ENV_ARG_LIMIT
 
 config LOCALVERSION
 	string "Local version - append to kernel release"
+	default "-ipipe"
 	help
 	  Append an extra string to the end of your kernel version.
 	  This will show up when you type uname, for example.
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/init/main.c b/init/main.c
index 7e117a2..43474f4 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/init/main.c
+++ b/init/main.c
@@ -555,7 +555,7 @@ asmlinkage void __init start_kernel(void)
 	debug_objects_early_init();
 	cgroup_init_early();
 
-	local_irq_disable();
+	local_irq_disable_hw();
 	early_boot_irqs_off();
 	early_init_irq_lock_class();
 
@@ -611,6 +611,11 @@ asmlinkage void __init start_kernel(void)
 	timekeeping_init();
 	time_init();
 	sched_clock_init();
+ 	/*
+ 	 * We need to wait for the interrupt and time subsystems to be
+ 	 * initialized before enabling the pipeline.
+ 	 */
+  	ipipe_init();
 	profile_init();
 	if (!irqs_disabled())
 		printk("start_kernel(): bug: interrupts were enabled early\n");
@@ -772,6 +777,7 @@ static void __init do_basic_setup(void)
 	usermodehelper_init();
 	driver_init();
 	init_irq_proc();
+ 	ipipe_init_proc();
 	do_initcalls();
 }
 
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/Makefile b/kernel/Makefile
index 19fad00..e36e4e3 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/Makefile
+++ b/kernel/Makefile
@@ -79,6 +79,7 @@ ifeq ($(CONFIG_PREEMPT_RCU),y)
 obj-$(CONFIG_RCU_TRACE) += rcupreempt_trace.o
 endif
 obj-$(CONFIG_RELAY) += relay.o
+obj-$(CONFIG_IPIPE) += ipipe/
 obj-$(CONFIG_SYSCTL) += utsname_sysctl.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/exit.c b/kernel/exit.c
index 10e393b..c74548a 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/exit.c
+++ b/kernel/exit.c
@@ -1072,6 +1072,7 @@ NORET_TYPE void do_exit(long code)
 		acct_process();
 	trace_sched_process_exit(tsk);
 
+  	ipipe_exit_notify(tsk);
 	exit_sem(tsk);
 	exit_files(tsk);
 	exit_fs(tsk);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/fork.c b/kernel/fork.c
index f2c9c60..52c157f 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/fork.c
+++ b/kernel/fork.c
@@ -468,6 +468,7 @@ void mmput(struct mm_struct *mm)
 	if (atomic_dec_and_test(&mm->mm_users)) {
 		exit_aio(mm);
 		exit_mmap(mm);
+ 		ipipe_cleanup_notify(mm);
 		set_mm_exe_file(mm, NULL);
 		if (!list_empty(&mm->mmlist)) {
 			spin_lock(&mmlist_lock);
@@ -887,7 +888,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
 {
 	unsigned long new_flags = p->flags;
 
-	new_flags &= ~PF_SUPERPRIV;
+ 	new_flags &= ~(PF_SUPERPRIV | PF_EVNOTIFY);
 	new_flags |= PF_FORKNOEXEC;
 	new_flags |= PF_STARTING;
 	p->flags = new_flags;
@@ -1272,6 +1273,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	write_unlock_irq(&tasklist_lock);
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
+#ifdef CONFIG_IPIPE
+	memset(p->ptd, 0, sizeof(p->ptd));
+#endif /* CONFIG_IPIPE */
 	return p;
 
 bad_fork_free_pid:
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/ipipe/Kconfig b/kernel/ipipe/Kconfig
new file mode 100644
index 0000000..de5e6a3
--- /dev/null
+++ b/kernel/ipipe/Kconfig
@@ -0,0 +1,35 @@
+config IPIPE
+	bool "Interrupt pipeline"
+	default y
+	---help---
+	  Activate this option if you want the interrupt pipeline to be
+	  compiled in.
+
+config IPIPE_DOMAINS
+	int "Max domains"
+	depends on IPIPE
+	default 4
+	---help---
+	The maximum number of I-pipe domains to run concurrently.
+
+config IPIPE_COMPAT
+	bool "Maintain code compatibility with older releases"
+	depends on IPIPE
+	default y
+	---help---
+	Activate this option if you want the compatibility code to be
+	defined, so that older I-pipe clients may use obsolete
+	constructs. WARNING: obsolete code will be eventually
+	deprecated in future I-pipe releases, and removed from the
+	compatibility support as time passes. Please fix I-pipe
+	clients to get rid of such uses as soon as possible.
+
+config IPIPE_DELAYED_ATOMICSW
+       bool
+       depends on IPIPE
+       default n
+
+config IPIPE_UNMASKED_CONTEXT_SWITCH
+       bool
+       depends on IPIPE
+       default n
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/ipipe/Kconfig.debug b/kernel/ipipe/Kconfig.debug
new file mode 100644
index 0000000..64a692c
--- /dev/null
+++ b/kernel/ipipe/Kconfig.debug
@@ -0,0 +1,88 @@
+config IPIPE_DEBUG
+	bool "I-pipe debugging"
+	depends on IPIPE
+
+config IPIPE_DEBUG_CONTEXT
+	bool "Check for illicit cross-domain calls"
+	depends on IPIPE_DEBUG
+	default y
+	---help---
+	  Enable this feature to arm checkpoints in the kernel that
+	  verify the correct invocation context. On entry of critical
+	  Linux services a warning is issued if the caller is not
+	  running over the root domain.
+
+config IPIPE_TRACE
+	bool "Latency tracing"
+	depends on IPIPE_DEBUG
+	select FRAME_POINTER
+	select KALLSYMS
+	select PROC_FS
+	---help---
+	  Activate this option if you want to use per-function tracing of
+	  the kernel. The tracer will collect data via instrumentation
+	  features like the one below or with the help of explicite calls
+	  of ipipe_trace_xxx(). See include/linux/ipipe_trace.h for the
+	  in-kernel tracing API. The collected data and runtime control
+	  is available via /proc/ipipe/trace/*.
+
+if IPIPE_TRACE
+
+config IPIPE_TRACE_ENABLE
+	bool "Enable tracing on boot"
+	default y
+	---help---
+	  Disable this option if you want to arm the tracer after booting
+	  manually ("echo 1 > /proc/ipipe/tracer/enable"). This can reduce
+	  boot time on slow embedded devices due to the tracer overhead.
+
+config IPIPE_TRACE_MCOUNT
+	bool "Instrument function entries"
+	default y
+	---help---
+	  When enabled, records every kernel function entry in the tracer
+	  log. While this slows down the system noticeably, it provides
+	  the highest level of information about the flow of events.
+	  However, it can be switch off in order to record only explicit
+	  I-pipe trace points.
+
+config IPIPE_TRACE_IRQSOFF
+	bool "Trace IRQs-off times"
+	default y
+	---help---
+	  Activate this option if I-pipe shall trace the longest path
+	  with hard-IRQs switched off.
+
+config IPIPE_TRACE_SHIFT
+	int "Depth of trace log (14 => 16Kpoints, 15 => 32Kpoints)"
+	range 10 18
+	default 14
+	---help---
+	  The number of trace points to hold tracing data for each
+	  trace path, as a power of 2.
+
+config IPIPE_TRACE_VMALLOC
+	bool "Use vmalloc'ed trace buffer"
+	default y if EMBEDDED
+	---help---
+	  Instead of reserving static kernel data, the required buffer
+	  is allocated via vmalloc during boot-up when this option is
+	  enabled. This can help to start systems that are low on memory,
+	  but it slightly degrades overall performance. Try this option
+	  when a traced kernel hangs unexpectedly at boot time.
+
+config IPIPE_TRACE_PANIC
+	bool "Enable panic back traces"
+	default y
+	---help---
+	  Provides services to freeze and dump a back trace on panic
+	  situations. This is used on IPIPE_DEBUG_CONTEXT exceptions
+	  as well as ordinary kernel oopses. You can control the number
+	  of printed back trace points via /proc/ipipe/trace.
+
+config IPIPE_TRACE_ENABLE_VALUE
+	int
+	default 0 if !IPIPE_TRACE_ENABLE
+	default 1 if IPIPE_TRACE_ENABLE
+
+endif
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/ipipe/Makefile b/kernel/ipipe/Makefile
new file mode 100644
index 0000000..6257dfa
--- /dev/null
+++ b/kernel/ipipe/Makefile
@@ -0,0 +1,3 @@
+
+obj-$(CONFIG_IPIPE)	+= core.o
+obj-$(CONFIG_IPIPE_TRACE) += tracer.o
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/ipipe/core.c b/kernel/ipipe/core.c
new file mode 100644
index 0000000..97e6aae
--- /dev/null
+++ b/kernel/ipipe/core.c
@@ -0,0 +1,1713 @@
+/* -*- linux-c -*-
+ * linux/kernel/ipipe/core.c
+ *
+ * Copyright (C) 2002-2005 Philippe Gerum.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Architecture-independent I-PIPE core support.
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/sched.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/tick.h>
+#include <linux/prefetch.h>
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#endif	/* CONFIG_PROC_FS */
+#include <linux/ipipe_trace.h>
+#include <linux/ipipe_tickdev.h>
+#include <linux/irq.h>
+
+static int __ipipe_ptd_key_count;
+
+static unsigned long __ipipe_ptd_key_map;
+
+static unsigned long __ipipe_domain_slot_map;
+
+struct ipipe_domain ipipe_root;
+
+#ifndef CONFIG_SMP
+/*
+ * Create an alias to the unique root status, so that arch-dep code
+ * may get simple and easy access to this percpu variable.  We also
+ * create an array of pointers to the percpu domain data; this tends
+ * to produce a better code when reaching non-root domains. We make
+ * sure that the early boot code would be able to dereference the
+ * pointer to the root domain data safely by statically initializing
+ * its value (local_irq*() routines depend on this).
+ */
+#if __GNUC__ >= 4
+extern unsigned long __ipipe_root_status
+__attribute__((alias(__stringify(__raw_get_cpu_var(ipipe_percpu_darray)))));
+EXPORT_SYMBOL(__ipipe_root_status);
+#else /* __GNUC__ < 4 */
+/*
+ * Work around a GCC 3.x issue making alias symbols unusable as
+ * constant initializers.
+ */
+unsigned long *const __ipipe_root_status_addr =
+	&__raw_get_cpu_var(ipipe_percpu_darray)[IPIPE_ROOT_SLOT].status;
+EXPORT_SYMBOL(__ipipe_root_status_addr);
+#endif /* __GNUC__ < 4 */
+
+DEFINE_PER_CPU(struct ipipe_percpu_domain_data *, ipipe_percpu_daddr[CONFIG_IPIPE_DOMAINS]) =
+{ [IPIPE_ROOT_SLOT] = (struct ipipe_percpu_domain_data *)&__raw_get_cpu_var(ipipe_percpu_darray) };
+EXPORT_PER_CPU_SYMBOL(ipipe_percpu_daddr);
+#endif /* !CONFIG_SMP */
+
+DEFINE_PER_CPU(struct ipipe_percpu_domain_data, ipipe_percpu_darray[CONFIG_IPIPE_DOMAINS]) =
+{ [IPIPE_ROOT_SLOT] = { .status = IPIPE_STALL_MASK } }; /* Root domain stalled on each CPU at startup. */
+
+DEFINE_PER_CPU(struct ipipe_domain *, ipipe_percpu_domain) = { &ipipe_root };
+
+DEFINE_PER_CPU(unsigned long, ipipe_nmi_saved_root); /* Copy of root status during NMI */
+
+static IPIPE_DEFINE_SPINLOCK(__ipipe_pipelock);
+
+LIST_HEAD(__ipipe_pipeline);
+
+unsigned long __ipipe_virtual_irq_map;
+
+#ifdef CONFIG_PRINTK
+unsigned __ipipe_printk_virq;
+#endif /* CONFIG_PRINTK */
+
+int __ipipe_event_monitors[IPIPE_NR_EVENTS];
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+
+DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+
+static DEFINE_PER_CPU(struct ipipe_tick_device, ipipe_tick_cpu_device);
+
+int ipipe_request_tickdev(const char *devname,
+			  void (*emumode)(enum clock_event_mode mode,
+					  struct clock_event_device *cdev),
+			  int (*emutick)(unsigned long delta,
+					 struct clock_event_device *cdev),
+			  int cpu, unsigned long *tmfreq)
+{
+	struct ipipe_tick_device *itd;
+	struct tick_device *slave;
+	struct clock_event_device *evtdev;
+	unsigned long long freq;
+	unsigned long flags;
+	int status;
+
+	flags = ipipe_critical_enter(NULL);
+
+	itd = &per_cpu(ipipe_tick_cpu_device, cpu);
+
+	if (itd->slave != NULL) {
+		status = -EBUSY;
+		goto out;
+	}
+
+	slave = &per_cpu(tick_cpu_device, cpu);
+
+	if (strcmp(slave->evtdev->name, devname)) {
+		/*
+		 * No conflict so far with the current tick device,
+		 * check whether the requested device is sane and has
+		 * been blessed by the kernel.
+		 */
+		status = __ipipe_check_tickdev(devname) ?
+			CLOCK_EVT_MODE_UNUSED : CLOCK_EVT_MODE_SHUTDOWN;
+		goto out;
+	}
+
+	/*
+	 * Our caller asks for using the same clock event device for
+	 * ticking than we do, let's create a tick emulation device to
+	 * interpose on the set_next_event() method, so that we may
+	 * both manage the device in oneshot mode. Only the tick
+	 * emulation code will actually program the clockchip hardware
+	 * for the next shot, though.
+	 *
+	 * CAUTION: we still have to grab the tick device even when it
+	 * current runs in periodic mode, since the kernel may switch
+	 * to oneshot dynamically (highres/no_hz tick mode).
+	 */
+
+	evtdev = slave->evtdev;
+	status = evtdev->mode;
+
+        if (status == CLOCK_EVT_MODE_SHUTDOWN)
+                goto out;
+
+	itd->slave = slave;
+	itd->emul_set_mode = emumode;
+	itd->emul_set_tick = emutick;
+	itd->real_set_mode = evtdev->set_mode;
+	itd->real_set_tick = evtdev->set_next_event;
+	itd->real_max_delta_ns = evtdev->max_delta_ns;
+	itd->real_mult = evtdev->mult;
+	itd->real_shift = evtdev->shift;
+	freq = (1000000000ULL * evtdev->mult) >> evtdev->shift;
+	*tmfreq = (unsigned long)freq;
+	evtdev->set_mode = emumode;
+	evtdev->set_next_event = emutick;
+	evtdev->max_delta_ns = ULONG_MAX;
+	evtdev->mult = 1;
+	evtdev->shift = 0;
+out:
+	ipipe_critical_exit(flags);
+
+	return status;
+}
+
+void ipipe_release_tickdev(int cpu)
+{
+	struct ipipe_tick_device *itd;
+	struct tick_device *slave;
+	struct clock_event_device *evtdev;
+	unsigned long flags;
+
+	flags = ipipe_critical_enter(NULL);
+
+	itd = &per_cpu(ipipe_tick_cpu_device, cpu);
+
+	if (itd->slave != NULL) {
+		slave = &per_cpu(tick_cpu_device, cpu);
+		evtdev = slave->evtdev;
+		evtdev->set_mode = itd->real_set_mode;
+		evtdev->set_next_event = itd->real_set_tick;
+		evtdev->max_delta_ns = itd->real_max_delta_ns;
+		evtdev->mult = itd->real_mult;
+		evtdev->shift = itd->real_shift;
+		itd->slave = NULL;
+	}
+
+	ipipe_critical_exit(flags);
+}
+
+#endif /* CONFIG_GENERIC_CLOCKEVENTS */
+
+/*
+ * ipipe_init() -- Initialization routine of the IPIPE layer. Called
+ * by the host kernel early during the boot procedure.
+ */
+void __init ipipe_init(void)
+{
+	struct ipipe_domain *ipd = &ipipe_root;
+
+	__ipipe_check_platform();	/* Do platform dependent checks first. */
+
+	/*
+	 * A lightweight registration code for the root domain. We are
+	 * running on the boot CPU, hw interrupts are off, and
+	 * secondary CPUs are still lost in space.
+	 */
+
+	/* Reserve percpu data slot #0 for the root domain. */
+	ipd->slot = 0;
+	set_bit(0, &__ipipe_domain_slot_map);
+
+	ipd->name = "Linux";
+	ipd->domid = IPIPE_ROOT_ID;
+	ipd->priority = IPIPE_ROOT_PRIO;
+
+	__ipipe_init_stage(ipd);
+
+	INIT_LIST_HEAD(&ipd->p_link);
+	list_add_tail(&ipd->p_link, &__ipipe_pipeline);
+
+	__ipipe_init_platform();
+
+#ifdef CONFIG_PRINTK
+	__ipipe_printk_virq = ipipe_alloc_virq();	/* Cannot fail here. */
+	ipd->irqs[__ipipe_printk_virq].handler = &__ipipe_flush_printk;
+	ipd->irqs[__ipipe_printk_virq].cookie = NULL;
+	ipd->irqs[__ipipe_printk_virq].acknowledge = NULL;
+	ipd->irqs[__ipipe_printk_virq].control = IPIPE_HANDLE_MASK;
+#endif /* CONFIG_PRINTK */
+
+	__ipipe_enable_pipeline();
+
+	printk(KERN_INFO "I-pipe %s: pipeline enabled.\n",
+	       IPIPE_VERSION_STRING);
+}
+
+void __ipipe_init_stage(struct ipipe_domain *ipd)
+{
+	int cpu, n;
+
+	for_each_online_cpu(cpu) {
+
+		ipipe_percpudom(ipd, irqpend_himask, cpu) = 0;
+
+		for (n = 0; n < IPIPE_IRQ_IWORDS; n++) {
+			ipipe_percpudom(ipd, irqpend_lomask, cpu)[n] = 0;
+			ipipe_percpudom(ipd, irqheld_mask, cpu)[n] = 0;
+		}
+
+		for (n = 0; n < IPIPE_NR_IRQS; n++)
+			ipipe_percpudom(ipd, irqall, cpu)[n] = 0;
+
+		ipipe_percpudom(ipd, evsync, cpu) = 0;
+	}
+
+	for (n = 0; n < IPIPE_NR_IRQS; n++) {
+		ipd->irqs[n].acknowledge = NULL;
+		ipd->irqs[n].handler = NULL;
+		ipd->irqs[n].control = IPIPE_PASS_MASK;	/* Pass but don't handle */
+	}
+
+	for (n = 0; n < IPIPE_NR_EVENTS; n++)
+		ipd->evhand[n] = NULL;
+
+	ipd->evself = 0LL;
+	mutex_init(&ipd->mutex);
+
+	__ipipe_hook_critical_ipi(ipd);
+}
+
+void __ipipe_cleanup_domain(struct ipipe_domain *ipd)
+{
+	ipipe_unstall_pipeline_from(ipd);
+
+#ifdef CONFIG_SMP
+	{
+		int cpu;
+
+		for_each_online_cpu(cpu) {
+			while (ipipe_percpudom(ipd, irqpend_himask, cpu) != 0)
+				cpu_relax();
+		}
+	}
+#else
+	__raw_get_cpu_var(ipipe_percpu_daddr)[ipd->slot] = NULL;
+#endif
+
+	clear_bit(ipd->slot, &__ipipe_domain_slot_map);
+}
+
+void __ipipe_unstall_root(void)
+{
+	struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr();
+
+#ifndef CONFIG_IPIPE_DEBUG_CONTEXT
+	BUG_ON(!ipipe_root_domain_p);
+#endif
+
+        local_irq_disable_hw();
+
+        __clear_bit(IPIPE_STALL_FLAG, &p->status);
+
+        if (unlikely(p->irqpend_himask != 0))
+                __ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+
+        local_irq_enable_hw();
+}
+
+void __ipipe_restore_root(unsigned long x)
+{
+#ifndef CONFIG_IPIPE_DEBUG_CONTEXT
+	BUG_ON(!ipipe_root_domain_p);
+#endif
+
+	if (x)
+		__ipipe_stall_root();
+	else
+		__ipipe_unstall_root();
+}
+
+void ipipe_stall_pipeline_from(struct ipipe_domain *ipd)
+{
+	set_bit_safe(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipd, status));
+
+	if (__ipipe_pipeline_head_p(ipd))
+		local_irq_disable_hw();
+}
+
+unsigned long ipipe_test_and_stall_pipeline_from(struct ipipe_domain *ipd)
+{
+	unsigned long x;
+
+	x = test_and_set_bit_safe(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipd, status));
+
+	if (__ipipe_pipeline_head_p(ipd))
+		local_irq_disable_hw();
+
+	return x;
+}
+
+/*
+ * ipipe_unstall_pipeline_from() -- Unstall the pipeline and
+ * synchronize pending interrupts for a given domain. See
+ * __ipipe_walk_pipeline() for more information.
+ */
+void ipipe_unstall_pipeline_from(struct ipipe_domain *ipd)
+{
+	struct list_head *pos;
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+
+	__clear_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipd, status));
+
+	if (ipd == ipipe_current_domain)
+		pos = &ipd->p_link;
+	else
+		pos = __ipipe_pipeline.next;
+
+	__ipipe_walk_pipeline(pos);
+
+	if (likely(__ipipe_pipeline_head_p(ipd)))
+		local_irq_enable_hw();
+	else
+		local_irq_restore_hw(flags);
+}
+
+unsigned long ipipe_test_and_unstall_pipeline_from(struct ipipe_domain *ipd)
+{
+	unsigned long x;
+
+	x = test_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipd, status));
+	ipipe_unstall_pipeline_from(ipd);
+
+	return x;
+}
+
+void ipipe_restore_pipeline_from(struct ipipe_domain *ipd,
+					  unsigned long x)
+{
+	if (x)
+		ipipe_stall_pipeline_from(ipd);
+	else
+		ipipe_unstall_pipeline_from(ipd);
+}
+
+void ipipe_unstall_pipeline_head(void)
+{
+	struct ipipe_percpu_domain_data *p = ipipe_head_cpudom_ptr();
+
+	local_irq_disable_hw();
+
+	__clear_bit(IPIPE_STALL_FLAG, &p->status);
+
+	if (unlikely(p->irqpend_himask != 0)) {
+		struct ipipe_domain *head_domain = __ipipe_pipeline_head();
+		if (likely(head_domain == ipipe_current_domain))
+			__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+		else
+			__ipipe_walk_pipeline(&head_domain->p_link);
+        }
+
+	local_irq_enable_hw();
+}
+
+void __ipipe_restore_pipeline_head(unsigned long x)
+{
+	struct ipipe_percpu_domain_data *p = ipipe_head_cpudom_ptr();
+
+	local_irq_disable_hw();
+
+	if (x) {
+#ifdef CONFIG_DEBUG_KERNEL
+		static int warned;
+		if (!warned && test_and_set_bit(IPIPE_STALL_FLAG, &p->status)) {
+			/*
+			 * Already stalled albeit ipipe_restore_pipeline_head()
+			 * should have detected it? Send a warning once.
+			 */
+			warned = 1;
+			printk(KERN_WARNING
+				   "I-pipe: ipipe_restore_pipeline_head() optimization failed.\n");
+			dump_stack();
+		}
+#else /* !CONFIG_DEBUG_KERNEL */
+		set_bit(IPIPE_STALL_FLAG, &p->status);
+#endif /* CONFIG_DEBUG_KERNEL */
+	}
+	else {
+		__clear_bit(IPIPE_STALL_FLAG, &p->status);
+		if (unlikely(p->irqpend_himask != 0)) {
+			struct ipipe_domain *head_domain = __ipipe_pipeline_head();
+			if (likely(head_domain == ipipe_current_domain))
+				__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			else
+				__ipipe_walk_pipeline(&head_domain->p_link);
+		}
+		local_irq_enable_hw();
+	}
+}
+
+void __ipipe_spin_lock_irq(raw_spinlock_t *lock)
+{
+	local_irq_disable_hw();
+	__raw_spin_lock(lock);
+	__set_bit(IPIPE_STALL_FLAG, &ipipe_this_cpudom_var(status));
+}
+
+void __ipipe_spin_unlock_irq(raw_spinlock_t *lock)
+{
+	__raw_spin_unlock(lock);
+	__clear_bit(IPIPE_STALL_FLAG, &ipipe_this_cpudom_var(status));
+	local_irq_enable_hw();
+}
+
+unsigned long __ipipe_spin_lock_irqsave(raw_spinlock_t *lock)
+{
+	unsigned long flags;
+	int s;
+
+	local_irq_save_hw(flags);
+	__raw_spin_lock(lock);
+	s = __test_and_set_bit(IPIPE_STALL_FLAG, &ipipe_this_cpudom_var(status));
+
+	return raw_mangle_irq_bits(s, flags);
+}
+
+void __ipipe_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long x)
+{
+	__raw_spin_unlock(lock);
+	if (!raw_demangle_irq_bits(&x))
+		__clear_bit(IPIPE_STALL_FLAG, &ipipe_this_cpudom_var(status));
+	local_irq_restore_hw(x);
+}
+
+void __ipipe_spin_unlock_irqbegin(ipipe_spinlock_t *lock)
+{
+	__raw_spin_unlock(&lock->__raw_lock);
+}
+
+void __ipipe_spin_unlock_irqcomplete(unsigned long x)
+{
+	if (!raw_demangle_irq_bits(&x))
+		__clear_bit(IPIPE_STALL_FLAG, &ipipe_this_cpudom_var(status));
+	local_irq_restore_hw(x);
+}
+
+/* Must be called hw IRQs off. */
+void __ipipe_set_irq_pending(struct ipipe_domain *ipd, unsigned irq)
+{
+	int level = irq >> IPIPE_IRQ_ISHIFT, rank = irq & IPIPE_IRQ_IMASK;
+	struct ipipe_percpu_domain_data *p = ipipe_cpudom_ptr(ipd);
+
+	prefetchw(p);
+	
+	if (likely(!test_bit(IPIPE_LOCK_FLAG, &ipd->irqs[irq].control))) {
+		__set_bit(rank, &p->irqpend_lomask[level]);
+		__set_bit(level, &p->irqpend_himask);
+	} else
+		__set_bit(rank, &p->irqheld_mask[level]);
+
+	p->irqall[irq]++;
+}
+
+/* Must be called hw IRQs off. */
+void __ipipe_lock_irq(struct ipipe_domain *ipd, int cpu, unsigned irq)
+{
+	struct ipipe_percpu_domain_data *p;
+	int level, rank;
+
+	if (unlikely(test_and_set_bit(IPIPE_LOCK_FLAG, &ipd->irqs[irq].control)))
+		return;
+
+	level = irq >> IPIPE_IRQ_ISHIFT;
+	rank = irq & IPIPE_IRQ_IMASK;
+	p = ipipe_percpudom_ptr(ipd, cpu);
+
+	if (__test_and_clear_bit(rank, &p->irqpend_lomask[level]))
+		__set_bit(rank, &p->irqheld_mask[level]);
+	if (p->irqpend_lomask[level] == 0)
+		__clear_bit(level, &p->irqpend_himask);
+}
+
+/* Must be called hw IRQs off. */
+void __ipipe_unlock_irq(struct ipipe_domain *ipd, unsigned irq)
+{
+	struct ipipe_percpu_domain_data *p;
+	int cpu, level, rank;
+
+	if (unlikely(!test_and_clear_bit(IPIPE_LOCK_FLAG, &ipd->irqs[irq].control)))
+		return;
+
+	level = irq >> IPIPE_IRQ_ISHIFT, rank = irq & IPIPE_IRQ_IMASK;
+	for_each_online_cpu(cpu) {
+		p = ipipe_percpudom_ptr(ipd, cpu);
+		if (test_and_clear_bit(rank, &p->irqheld_mask[level])) {
+			/* We need atomic ops here: */
+			set_bit(rank, &p->irqpend_lomask[level]);
+			set_bit(level, &p->irqpend_himask);
+		}
+	}
+}
+
+/*
+ * __ipipe_walk_pipeline(): Plays interrupts pending in the log. Must
+ * be called with local hw interrupts disabled.
+ */
+void __ipipe_walk_pipeline(struct list_head *pos)
+{
+	struct ipipe_domain *this_domain = ipipe_current_domain, *next_domain;
+	struct ipipe_percpu_domain_data *p, *np;
+
+	p = ipipe_cpudom_ptr(this_domain);
+
+	while (pos != &__ipipe_pipeline) {
+
+		next_domain = list_entry(pos, struct ipipe_domain, p_link);
+		np = ipipe_cpudom_ptr(next_domain);
+
+		if (test_bit(IPIPE_STALL_FLAG, &np->status))
+			break;	/* Stalled stage -- do not go further. */
+
+		if (np->irqpend_himask) {
+			if (next_domain == this_domain)
+				__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			else {
+
+				p->evsync = 0;
+				ipipe_current_domain = next_domain;
+				ipipe_suspend_domain();	/* Sync stage and propagate interrupts. */
+
+				if (ipipe_current_domain == next_domain)
+					ipipe_current_domain = this_domain;
+				/*
+				 * Otherwise, something changed the current domain under our
+				 * feet recycling the register set; do not override the new
+				 * domain.
+				 */
+
+				if (p->irqpend_himask &&
+				    !test_bit(IPIPE_STALL_FLAG, &p->status))
+					__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			}
+			break;
+		} else if (next_domain == this_domain)
+			break;
+
+		pos = next_domain->p_link.next;
+	}
+}
+
+/*
+ * ipipe_suspend_domain() -- Suspend the current domain, switching to
+ * the next one which has pending work down the pipeline.
+ */
+void ipipe_suspend_domain(void)
+{
+	struct ipipe_domain *this_domain, *next_domain;
+	struct ipipe_percpu_domain_data *p;
+	struct list_head *ln;
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+
+	this_domain = next_domain = ipipe_current_domain;
+	p = ipipe_cpudom_ptr(this_domain);
+	p->status &= ~(IPIPE_STALL_MASK|IPIPE_SYNC_MASK);
+
+	if (p->irqpend_himask != 0)
+		goto sync_stage;
+
+	for (;;) {
+		ln = next_domain->p_link.next;
+
+		if (ln == &__ipipe_pipeline)
+			break;
+
+		next_domain = list_entry(ln, struct ipipe_domain, p_link);
+		p = ipipe_cpudom_ptr(next_domain);
+
+		if (p->status & IPIPE_STALL_MASK)
+			break;
+
+		if (p->irqpend_himask == 0)
+			continue;
+
+		ipipe_current_domain = next_domain;
+sync_stage:
+		__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+
+		if (ipipe_current_domain != next_domain)
+			/*
+			 * Something has changed the current domain under our
+			 * feet, recycling the register set; take note.
+			 */
+			this_domain = ipipe_current_domain;
+	}
+
+	ipipe_current_domain = this_domain;
+
+	local_irq_restore_hw(flags);
+}
+
+
+/* ipipe_alloc_virq() -- Allocate a pipelined virtual/soft interrupt.
+ * Virtual interrupts are handled in exactly the same way than their
+ * hw-generated counterparts wrt pipelining.
+ */
+unsigned ipipe_alloc_virq(void)
+{
+	unsigned long flags, irq = 0;
+	int ipos;
+
+	spin_lock_irqsave(&__ipipe_pipelock, flags);
+
+	if (__ipipe_virtual_irq_map != ~0) {
+		ipos = ffz(__ipipe_virtual_irq_map);
+		set_bit(ipos, &__ipipe_virtual_irq_map);
+		irq = ipos + IPIPE_VIRQ_BASE;
+	}
+
+	spin_unlock_irqrestore(&__ipipe_pipelock, flags);
+
+	return irq;
+}
+
+/* ipipe_virtualize_irq() -- Attach a handler (and optionally a hw
+   acknowledge routine) to an interrupt for a given domain. */
+
+int ipipe_virtualize_irq(struct ipipe_domain *ipd,
+			 unsigned irq,
+			 ipipe_irq_handler_t handler,
+			 void *cookie,
+			 ipipe_irq_ackfn_t acknowledge,
+			 unsigned modemask)
+{
+	unsigned long flags;
+	int err;
+
+	if (irq >= IPIPE_NR_IRQS)
+		return -EINVAL;
+
+	if (ipd->irqs[irq].control & IPIPE_SYSTEM_MASK)
+		return -EPERM;
+
+	if (!test_bit(IPIPE_AHEAD_FLAG, &ipd->flags))
+		/* Silently unwire interrupts for non-heading domains. */
+		modemask &= ~IPIPE_WIRED_MASK;
+
+	spin_lock_irqsave(&__ipipe_pipelock, flags);
+
+	if (handler != NULL) {
+		if (handler == IPIPE_SAME_HANDLER) {
+			handler = ipd->irqs[irq].handler;
+			cookie = ipd->irqs[irq].cookie;
+
+			if (handler == NULL) {
+				err = -EINVAL;
+				goto unlock_and_exit;
+			}
+		} else if ((modemask & IPIPE_EXCLUSIVE_MASK) != 0 &&
+			   ipd->irqs[irq].handler != NULL) {
+			err = -EBUSY;
+			goto unlock_and_exit;
+		}
+
+		/* Wired interrupts can only be delivered to domains
+		 * always heading the pipeline, and using dynamic
+		 * propagation. */
+
+		if ((modemask & IPIPE_WIRED_MASK) != 0) {
+			if ((modemask & (IPIPE_PASS_MASK | IPIPE_STICKY_MASK)) != 0) {
+				err = -EINVAL;
+				goto unlock_and_exit;
+			}
+			modemask |= (IPIPE_HANDLE_MASK);
+		}
+
+		if ((modemask & IPIPE_STICKY_MASK) != 0)
+			modemask |= IPIPE_HANDLE_MASK;
+	} else
+		modemask &=
+		    ~(IPIPE_HANDLE_MASK | IPIPE_STICKY_MASK |
+		      IPIPE_EXCLUSIVE_MASK | IPIPE_WIRED_MASK);
+
+	if (acknowledge == NULL && !ipipe_virtual_irq_p(irq))
+		/* Acknowledge handler unspecified for a hw interrupt:
+		   use the Linux-defined handler instead. */
+		acknowledge = ipipe_root_domain->irqs[irq].acknowledge;
+
+	ipd->irqs[irq].handler = handler;
+	ipd->irqs[irq].cookie = cookie;
+	ipd->irqs[irq].acknowledge = acknowledge;
+	ipd->irqs[irq].control = modemask;
+
+	if (irq < NR_IRQS && handler != NULL && !ipipe_virtual_irq_p(irq)) {
+		__ipipe_enable_irqdesc(ipd, irq);
+
+		if ((modemask & IPIPE_ENABLE_MASK) != 0) {
+			if (ipd != ipipe_current_domain) {
+				/* IRQ enable/disable state is domain-sensitive, so we may
+				   not change it for another domain. What is allowed
+				   however is forcing some domain to handle an interrupt
+				   source, by passing the proper 'ipd' descriptor which
+				   thus may be different from ipipe_current_domain. */
+				err = -EPERM;
+				goto unlock_and_exit;
+			}
+			__ipipe_enable_irq(irq);
+		}
+	}
+
+	err = 0;
+
+      unlock_and_exit:
+
+	spin_unlock_irqrestore(&__ipipe_pipelock, flags);
+
+	return err;
+}
+
+/* ipipe_control_irq() -- Change modes of a pipelined interrupt for
+ * the current domain. */
+
+int ipipe_control_irq(unsigned irq, unsigned clrmask, unsigned setmask)
+{
+	struct ipipe_domain *ipd;
+	unsigned long flags;
+
+	if (irq >= IPIPE_NR_IRQS)
+		return -EINVAL;
+
+	ipd = ipipe_current_domain;
+
+	if (ipd->irqs[irq].control & IPIPE_SYSTEM_MASK)
+		return -EPERM;
+
+	if (ipd->irqs[irq].handler == NULL)
+		setmask &= ~(IPIPE_HANDLE_MASK | IPIPE_STICKY_MASK);
+
+	if ((setmask & IPIPE_STICKY_MASK) != 0)
+		setmask |= IPIPE_HANDLE_MASK;
+
+	if ((clrmask & (IPIPE_HANDLE_MASK | IPIPE_STICKY_MASK)) != 0)	/* If one goes, both go. */
+		clrmask |= (IPIPE_HANDLE_MASK | IPIPE_STICKY_MASK);
+
+	spin_lock_irqsave(&__ipipe_pipelock, flags);
+
+	ipd->irqs[irq].control &= ~clrmask;
+	ipd->irqs[irq].control |= setmask;
+
+	if ((setmask & IPIPE_ENABLE_MASK) != 0)
+		__ipipe_enable_irq(irq);
+	else if ((clrmask & IPIPE_ENABLE_MASK) != 0)
+		__ipipe_disable_irq(irq);
+
+	spin_unlock_irqrestore(&__ipipe_pipelock, flags);
+
+	return 0;
+}
+
+/* __ipipe_dispatch_event() -- Low-level event dispatcher. */
+
+int __ipipe_dispatch_event (unsigned event, void *data)
+{
+	struct ipipe_domain *start_domain, *this_domain, *next_domain;
+	ipipe_event_handler_t evhand;
+	struct list_head *pos, *npos;
+	unsigned long flags;
+	int propagate = 1;
+
+	local_irq_save_hw(flags);
+
+	start_domain = this_domain = ipipe_current_domain;
+
+	list_for_each_safe(pos, npos, &__ipipe_pipeline) {
+		/*
+		 * Note: Domain migration may occur while running
+		 * event or interrupt handlers, in which case the
+		 * current register set is going to be recycled for a
+		 * different domain than the initiating one. We do
+		 * care for that, always tracking the current domain
+		 * descriptor upon return from those handlers.
+		 */
+		next_domain = list_entry(pos, struct ipipe_domain, p_link);
+
+		/*
+		 * Keep a cached copy of the handler's address since
+		 * ipipe_catch_event() may clear it under our feet.
+		 */
+		evhand = next_domain->evhand[event];
+
+		if (evhand != NULL) {
+			ipipe_current_domain = next_domain;
+			ipipe_cpudom_var(next_domain, evsync) |= (1LL << event);
+			local_irq_restore_hw(flags);
+			propagate = !evhand(event, start_domain, data);
+			local_irq_save_hw(flags);
+			/*
+			 * We may have a migration issue here, if the
+			 * current task is migrated to another CPU on
+			 * behalf of the invoked handler, usually when
+			 * a syscall event is processed. However,
+			 * ipipe_catch_event() will make sure that a
+			 * CPU that clears a handler for any given
+			 * event will not attempt to wait for itself
+			 * to clear the evsync bit for that event,
+			 * which practically plugs the hole, without
+			 * resorting to a much more complex strategy.
+			 */
+			ipipe_cpudom_var(next_domain, evsync) &= ~(1LL << event);
+			if (ipipe_current_domain != next_domain)
+				this_domain = ipipe_current_domain;
+		}
+
+		if (next_domain != ipipe_root_domain &&	/* NEVER sync the root stage here. */
+		    ipipe_cpudom_var(next_domain, irqpend_himask) != 0 &&
+		    !test_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(next_domain, status))) {
+			ipipe_current_domain = next_domain;
+			__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			if (ipipe_current_domain != next_domain)
+				this_domain = ipipe_current_domain;
+		}
+
+		ipipe_current_domain = this_domain;
+
+		if (next_domain == this_domain || !propagate)
+			break;
+	}
+
+	local_irq_restore_hw(flags);
+
+	return !propagate;
+}
+
+/*
+ * __ipipe_dispatch_wired -- Wired interrupt dispatcher. Wired
+ * interrupts are immediately and unconditionally delivered to the
+ * domain heading the pipeline upon receipt, and such domain must have
+ * been registered as an invariant head for the system (priority ==
+ * IPIPE_HEAD_PRIORITY). The motivation for using wired interrupts is
+ * to get an extra-fast dispatching path for those IRQs, by relying on
+ * a straightforward logic based on assumptions that must always be
+ * true for invariant head domains.  The following assumptions are
+ * made when dealing with such interrupts:
+ *
+ * 1- Wired interrupts are purely dynamic, i.e. the decision to
+ * propagate them down the pipeline must be done from the head domain
+ * ISR.
+ * 2- Wired interrupts cannot be shared or sticky.
+ * 3- The root domain cannot be an invariant pipeline head, in
+ * consequence of what the root domain cannot handle wired
+ * interrupts.
+ * 4- Wired interrupts must have a valid acknowledge handler for the
+ * head domain (if needed, see __ipipe_handle_irq).
+ *
+ * Called with hw interrupts off.
+ */
+
+void __ipipe_dispatch_wired(struct ipipe_domain *head, unsigned irq)
+{
+	struct ipipe_percpu_domain_data *p = ipipe_cpudom_ptr(head);
+
+	prefetchw(p);
+
+	if (unlikely(test_bit(IPIPE_LOCK_FLAG, &head->irqs[irq].control))) {
+		/*
+		 * If we can't process this IRQ right now, we must
+		 * mark it as held, so that it will get played during
+		 * normal log sync when the corresponding interrupt
+		 * source is eventually unlocked.
+		 */
+		p->irqall[irq]++;
+		__set_bit(irq & IPIPE_IRQ_IMASK, &p->irqheld_mask[irq >> IPIPE_IRQ_ISHIFT]);
+		return;
+	}
+
+	if (test_bit(IPIPE_STALL_FLAG, &p->status)) {
+		__ipipe_set_irq_pending(head, irq);
+		return;
+	}
+
+	__ipipe_dispatch_wired_nocheck(head, irq);
+}
+
+void __ipipe_dispatch_wired_nocheck(struct ipipe_domain *head, unsigned irq)
+{
+	struct ipipe_percpu_domain_data *p = ipipe_cpudom_ptr(head);
+	struct ipipe_domain *old;
+
+	prefetchw(p);
+
+	old = ipipe_current_domain;
+	ipipe_current_domain = head; /* Switch to the head domain. */
+
+	p->irqall[irq]++;
+	__set_bit(IPIPE_STALL_FLAG, &p->status);
+	head->irqs[irq].handler(irq, head->irqs[irq].cookie); /* Call the ISR. */
+	__ipipe_run_irqtail();
+	__clear_bit(IPIPE_STALL_FLAG, &p->status);
+
+	if (ipipe_current_domain == head) {
+		ipipe_current_domain = old;
+		if (old == head) {
+			if (p->irqpend_himask)
+				__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			return;
+		}
+	}
+
+	__ipipe_walk_pipeline(&head->p_link);
+}
+
+/*
+ * __ipipe_sync_stage() -- Flush the pending IRQs for the current
+ * domain (and processor). This routine flushes the interrupt log
+ * (see "Optimistic interrupt protection" from D. Stodolsky et al. for
+ * more on the deferred interrupt scheme). Every interrupt that
+ * occurred while the pipeline was stalled gets played. WARNING:
+ * callers on SMP boxen should always check for CPU migration on
+ * return of this routine. One can control the kind of interrupts
+ * which are going to be sync'ed using the syncmask
+ * parameter. IPIPE_IRQMASK_ANY plays them all, IPIPE_IRQMASK_VIRT
+ * plays virtual interrupts only.
+ *
+ * This routine must be called with hw interrupts off.
+ */
+void __ipipe_sync_stage(unsigned long syncmask)
+{
+	struct ipipe_percpu_domain_data *p;
+	unsigned long mask, submask;
+	struct ipipe_domain *ipd;
+	int level, rank, cpu;
+	unsigned irq;
+
+	ipd = ipipe_current_domain;
+	p = ipipe_cpudom_ptr(ipd);
+
+	if (__test_and_set_bit(IPIPE_SYNC_FLAG, &p->status))
+		return;
+
+	cpu = ipipe_processor_id();
+
+	/*
+	 * The policy here is to keep the dispatching code interrupt-free
+	 * by stalling the current stage. If the upper domain handler
+	 * (which we call) wants to re-enable interrupts while in a safe
+	 * portion of the code (e.g. SA_INTERRUPT flag unset for Linux's
+	 * sigaction()), it will have to unstall (then stall again before
+	 * returning to us!) the stage when it sees fit.
+	 */
+	while ((mask = (p->irqpend_himask & syncmask)) != 0) {
+		level = __ipipe_ffnz(mask);
+
+		while ((submask = p->irqpend_lomask[level]) != 0) {
+			rank = __ipipe_ffnz(submask);
+			irq = (level << IPIPE_IRQ_ISHIFT) + rank;
+
+			__clear_bit(rank, &p->irqpend_lomask[level]);
+
+			if (p->irqpend_lomask[level] == 0)
+				__clear_bit(level, &p->irqpend_himask);
+			/*
+			 * Make sure the compiler will not postpone
+			 * the pending bitmask updates before calling
+			 * the interrupt handling routine. Otherwise,
+			 * those late updates could overwrite any
+			 * change to irqpend_hi/lomask due to a nested
+			 * interrupt, leaving the latter unprocessed
+			 * (seen on mpc836x).
+			 */
+			barrier();
+
+			if (test_bit(IPIPE_LOCK_FLAG, &ipd->irqs[irq].control))
+				continue;
+
+			__set_bit(IPIPE_STALL_FLAG, &p->status);
+
+			if (ipd == ipipe_root_domain)
+				trace_hardirqs_off();
+
+			__ipipe_run_isr(ipd, irq);
+			p = ipipe_cpudom_ptr(ipipe_current_domain);
+#ifdef CONFIG_SMP
+			{
+				int newcpu = ipipe_processor_id();
+
+				if (newcpu != cpu) {	/* Handle CPU migration. */
+					/*
+					 * We expect any domain to clear the SYNC bit each
+					 * time it switches in a new task, so that preemptions
+					 * and/or CPU migrations (in the SMP case) over the
+					 * ISR do not lock out the log syncer for some
+					 * indefinite amount of time. In the Linux case,
+					 * schedule() handles this (see kernel/sched.c). For
+					 * this reason, we don't bother clearing it here for
+					 * the source CPU in the migration handling case,
+					 * since it must have scheduled another task in by
+					 * now.
+					 */
+					__set_bit(IPIPE_SYNC_FLAG, &p->status);
+					cpu = newcpu;
+				}
+			}
+#endif	/* CONFIG_SMP */
+#ifdef CONFIG_TRACE_IRQFLAGS
+			if (ipipe_root_domain_p &&
+			    test_bit(IPIPE_STALL_FLAG, &p->status))
+				trace_hardirqs_on();
+#endif
+			__clear_bit(IPIPE_STALL_FLAG, &p->status);
+		}
+	}
+
+	__clear_bit(IPIPE_SYNC_FLAG, &p->status);
+}
+
+/* ipipe_register_domain() -- Link a new domain to the pipeline. */
+
+int ipipe_register_domain(struct ipipe_domain *ipd,
+			  struct ipipe_domain_attr *attr)
+{
+	struct ipipe_domain *_ipd;
+	struct list_head *pos = NULL;
+	unsigned long flags;
+
+	if (!ipipe_root_domain_p) {
+		printk(KERN_WARNING
+		       "I-pipe: Only the root domain may register a new domain.\n");
+		return -EPERM;
+	}
+
+	flags = ipipe_critical_enter(NULL);
+
+	if (attr->priority == IPIPE_HEAD_PRIORITY) {
+		if (test_bit(IPIPE_HEAD_SLOT, &__ipipe_domain_slot_map)) {
+			ipipe_critical_exit(flags);
+			return -EAGAIN;	/* Cannot override current head. */
+		}
+		ipd->slot = IPIPE_HEAD_SLOT;
+	} else
+		ipd->slot = ffz(__ipipe_domain_slot_map);
+
+	if (ipd->slot < CONFIG_IPIPE_DOMAINS) {
+		set_bit(ipd->slot, &__ipipe_domain_slot_map);
+		list_for_each(pos, &__ipipe_pipeline) {
+			_ipd = list_entry(pos, struct ipipe_domain, p_link);
+			if (_ipd->domid == attr->domid)
+				break;
+		}
+	}
+
+	ipipe_critical_exit(flags);
+
+	if (pos != &__ipipe_pipeline) {
+		if (ipd->slot < CONFIG_IPIPE_DOMAINS)
+			clear_bit(ipd->slot, &__ipipe_domain_slot_map);
+		return -EBUSY;
+	}
+
+#ifndef CONFIG_SMP
+	/*
+	 * Set up the perdomain pointers for direct access to the
+	 * percpu domain data. This saves a costly multiply each time
+	 * we need to refer to the contents of the percpu domain data
+	 * array.
+	 */
+	__raw_get_cpu_var(ipipe_percpu_daddr)[ipd->slot] = &__raw_get_cpu_var(ipipe_percpu_darray)[ipd->slot];
+#endif
+
+	ipd->name = attr->name;
+	ipd->domid = attr->domid;
+	ipd->pdd = attr->pdd;
+	ipd->flags = 0;
+
+	if (attr->priority == IPIPE_HEAD_PRIORITY) {
+		ipd->priority = INT_MAX;
+		__set_bit(IPIPE_AHEAD_FLAG,&ipd->flags);
+	}
+	else
+		ipd->priority = attr->priority;
+
+	__ipipe_init_stage(ipd);
+
+	INIT_LIST_HEAD(&ipd->p_link);
+
+#ifdef CONFIG_PROC_FS
+	__ipipe_add_domain_proc(ipd);
+#endif /* CONFIG_PROC_FS */
+
+	flags = ipipe_critical_enter(NULL);
+
+	list_for_each(pos, &__ipipe_pipeline) {
+		_ipd = list_entry(pos, struct ipipe_domain, p_link);
+		if (ipd->priority > _ipd->priority)
+			break;
+	}
+
+	list_add_tail(&ipd->p_link, pos);
+
+	ipipe_critical_exit(flags);
+
+	printk(KERN_INFO "I-pipe: Domain %s registered.\n", ipd->name);
+
+	/*
+	 * Finally, allow the new domain to perform its initialization
+	 * chores.
+	 */
+
+	if (attr->entry != NULL) {
+		ipipe_current_domain = ipd;
+		attr->entry();
+		ipipe_current_domain = ipipe_root_domain;
+
+		local_irq_save_hw(flags);
+
+		if (ipipe_root_cpudom_var(irqpend_himask) != 0 &&
+		    !test_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status)))
+			__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+
+		local_irq_restore_hw(flags);
+	}
+
+	return 0;
+}
+
+/* ipipe_unregister_domain() -- Remove a domain from the pipeline. */
+
+int ipipe_unregister_domain(struct ipipe_domain *ipd)
+{
+	unsigned long flags;
+
+	if (!ipipe_root_domain_p) {
+		printk(KERN_WARNING
+		       "I-pipe: Only the root domain may unregister a domain.\n");
+		return -EPERM;
+	}
+
+	if (ipd == ipipe_root_domain) {
+		printk(KERN_WARNING
+		       "I-pipe: Cannot unregister the root domain.\n");
+		return -EPERM;
+	}
+#ifdef CONFIG_SMP
+	{
+		unsigned irq;
+		int cpu;
+
+		/*
+		 * In the SMP case, wait for the logged events to drain on
+		 * other processors before eventually removing the domain
+		 * from the pipeline.
+		 */
+
+		ipipe_unstall_pipeline_from(ipd);
+
+		flags = ipipe_critical_enter(NULL);
+
+		for (irq = 0; irq < IPIPE_NR_IRQS; irq++) {
+			clear_bit(IPIPE_HANDLE_FLAG, &ipd->irqs[irq].control);
+			clear_bit(IPIPE_STICKY_FLAG, &ipd->irqs[irq].control);
+			set_bit(IPIPE_PASS_FLAG, &ipd->irqs[irq].control);
+		}
+
+		ipipe_critical_exit(flags);
+
+		for_each_online_cpu(cpu) {
+			while (ipipe_percpudom(ipd, irqpend_himask, cpu) > 0)
+				cpu_relax();
+		}
+	}
+#endif	/* CONFIG_SMP */
+
+	mutex_lock(&ipd->mutex);
+
+#ifdef CONFIG_PROC_FS
+	__ipipe_remove_domain_proc(ipd);
+#endif /* CONFIG_PROC_FS */
+
+	/*
+	 * Simply remove the domain from the pipeline and we are almost done.
+	 */
+
+	flags = ipipe_critical_enter(NULL);
+	list_del_init(&ipd->p_link);
+	ipipe_critical_exit(flags);
+
+	__ipipe_cleanup_domain(ipd);
+
+	mutex_unlock(&ipd->mutex);
+
+	printk(KERN_INFO "I-pipe: Domain %s unregistered.\n", ipd->name);
+
+	return 0;
+}
+
+/*
+ * ipipe_propagate_irq() -- Force a given IRQ propagation on behalf of
+ * a running interrupt handler to the next domain down the pipeline.
+ * ipipe_schedule_irq() -- Does almost the same as above, but attempts
+ * to pend the interrupt for the current domain first.
+ * Must be called hw IRQs off.
+ */
+void __ipipe_pend_irq(unsigned irq, struct list_head *head)
+{
+	struct ipipe_domain *ipd;
+	struct list_head *ln;
+
+#ifdef CONFIG_IPIPE_DEBUG
+	BUG_ON(irq >= IPIPE_NR_IRQS ||
+	       (ipipe_virtual_irq_p(irq)
+		&& !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)));
+#endif
+	for (ln = head; ln != &__ipipe_pipeline; ln = ipd->p_link.next) {
+		ipd = list_entry(ln, struct ipipe_domain, p_link);
+		if (test_bit(IPIPE_HANDLE_FLAG, &ipd->irqs[irq].control)) {
+			__ipipe_set_irq_pending(ipd, irq);
+			return;
+		}
+	}
+}
+
+/* ipipe_free_virq() -- Release a virtual/soft interrupt. */
+
+int ipipe_free_virq(unsigned virq)
+{
+	if (!ipipe_virtual_irq_p(virq))
+		return -EINVAL;
+
+	clear_bit(virq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map);
+
+	return 0;
+}
+
+void ipipe_init_attr(struct ipipe_domain_attr *attr)
+{
+	attr->name = "anon";
+	attr->domid = 1;
+	attr->entry = NULL;
+	attr->priority = IPIPE_ROOT_PRIO;
+	attr->pdd = NULL;
+}
+
+/*
+ * ipipe_catch_event() -- Interpose or remove an event handler for a
+ * given domain.
+ */
+ipipe_event_handler_t ipipe_catch_event(struct ipipe_domain *ipd,
+					unsigned event,
+					ipipe_event_handler_t handler)
+{
+	ipipe_event_handler_t old_handler;
+	unsigned long flags;
+	int self = 0, cpu;
+
+	if (event & IPIPE_EVENT_SELF) {
+		event &= ~IPIPE_EVENT_SELF;
+		self = 1;
+	}
+
+	if (event >= IPIPE_NR_EVENTS)
+		return NULL;
+
+	flags = ipipe_critical_enter(NULL);
+
+	if (!(old_handler = xchg(&ipd->evhand[event],handler)))	{
+		if (handler) {
+			if (self)
+				ipd->evself |= (1LL << event);
+			else
+				__ipipe_event_monitors[event]++;
+		}
+	}
+	else if (!handler) {
+		if (ipd->evself & (1LL << event))
+			ipd->evself &= ~(1LL << event);
+		else
+			__ipipe_event_monitors[event]--;
+	} else if ((ipd->evself & (1LL << event)) && !self) {
+			__ipipe_event_monitors[event]++;
+			ipd->evself &= ~(1LL << event);
+	} else if (!(ipd->evself & (1LL << event)) && self) {
+			__ipipe_event_monitors[event]--;
+			ipd->evself |= (1LL << event);
+	}
+
+	ipipe_critical_exit(flags);
+
+	if (!handler && ipipe_root_domain_p) {
+		/*
+		 * If we cleared a handler on behalf of the root
+		 * domain, we have to wait for any current invocation
+		 * to drain, since our caller might subsequently unmap
+		 * the target domain. To this aim, this code
+		 * synchronizes with __ipipe_dispatch_event(),
+		 * guaranteeing that either the dispatcher sees a null
+		 * handler in which case it discards the invocation
+		 * (which also prevents from entering a livelock), or
+		 * finds a valid handler and calls it. Symmetrically,
+		 * ipipe_catch_event() ensures that the called code
+		 * won't be unmapped under our feet until the event
+		 * synchronization flag is cleared for the given event
+		 * on all CPUs.
+		 */
+		preempt_disable();
+		cpu = smp_processor_id();
+		/*
+		 * Hack: this solves the potential migration issue
+		 * raised in __ipipe_dispatch_event(). This is a
+		 * work-around which makes the assumption that other
+		 * CPUs will subsequently, either process at least one
+		 * interrupt for the target domain, or call
+		 * __ipipe_dispatch_event() without going through a
+		 * migration while running the handler at least once;
+		 * practically, this is safe on any normally running
+		 * system.
+		 */
+		ipipe_percpudom(ipd, evsync, cpu) &= ~(1LL << event);
+		preempt_enable();
+
+		for_each_online_cpu(cpu) {
+			while (ipipe_percpudom(ipd, evsync, cpu) & (1LL << event))
+				schedule_timeout_interruptible(HZ / 50);
+		}
+	}
+
+	return old_handler;
+}
+
+cpumask_t ipipe_set_irq_affinity (unsigned irq, cpumask_t cpumask)
+{
+#ifdef CONFIG_SMP
+	if (irq >= IPIPE_NR_XIRQS)
+		/* Allow changing affinity of external IRQs only. */
+		return CPU_MASK_NONE;
+
+	if (num_online_cpus() > 1)
+		return __ipipe_set_irq_affinity(irq,cpumask);
+#endif /* CONFIG_SMP */
+
+	return CPU_MASK_NONE;
+}
+
+int ipipe_send_ipi (unsigned ipi, cpumask_t cpumask)
+
+{
+#ifdef CONFIG_SMP
+	return __ipipe_send_ipi(ipi,cpumask);
+#else /* !CONFIG_SMP */
+	return -EINVAL;
+#endif /* CONFIG_SMP */
+}
+
+int ipipe_alloc_ptdkey (void)
+{
+	unsigned long flags;
+	int key = -1;
+
+	spin_lock_irqsave(&__ipipe_pipelock,flags);
+
+	if (__ipipe_ptd_key_count < IPIPE_ROOT_NPTDKEYS) {
+		key = ffz(__ipipe_ptd_key_map);
+		set_bit(key,&__ipipe_ptd_key_map);
+		__ipipe_ptd_key_count++;
+	}
+
+	spin_unlock_irqrestore(&__ipipe_pipelock,flags);
+
+	return key;
+}
+
+int ipipe_free_ptdkey (int key)
+{
+	unsigned long flags;
+
+	if (key < 0 || key >= IPIPE_ROOT_NPTDKEYS)
+		return -EINVAL;
+
+	spin_lock_irqsave(&__ipipe_pipelock,flags);
+
+	if (test_and_clear_bit(key,&__ipipe_ptd_key_map))
+		__ipipe_ptd_key_count--;
+
+	spin_unlock_irqrestore(&__ipipe_pipelock,flags);
+
+	return 0;
+}
+
+int ipipe_set_ptd (int key, void *value)
+
+{
+	if (key < 0 || key >= IPIPE_ROOT_NPTDKEYS)
+		return -EINVAL;
+
+	current->ptd[key] = value;
+
+	return 0;
+}
+
+void *ipipe_get_ptd (int key)
+
+{
+	if (key < 0 || key >= IPIPE_ROOT_NPTDKEYS)
+		return NULL;
+
+	return current->ptd[key];
+}
+
+#ifdef CONFIG_PROC_FS
+
+struct proc_dir_entry *ipipe_proc_root;
+
+static int __ipipe_version_info_proc(char *page,
+				     char **start,
+				     off_t off, int count, int *eof, void *data)
+{
+	int len = sprintf(page, "%s\n", IPIPE_VERSION_STRING);
+
+	len -= off;
+
+	if (len <= off + count)
+		*eof = 1;
+
+	*start = page + off;
+
+	if(len > count)
+		len = count;
+
+	if(len < 0)
+		len = 0;
+
+	return len;
+}
+
+static int __ipipe_common_info_show(struct seq_file *p, void *data)
+{
+	struct ipipe_domain *ipd = (struct ipipe_domain *)p->private;
+	char handling, stickiness, lockbit, exclusive, virtuality;
+
+	unsigned long ctlbits;
+	unsigned irq;
+
+	seq_printf(p, "       +----- Handling ([A]ccepted, [G]rabbed, [W]ired, [D]iscarded)\n");
+	seq_printf(p, "       |+---- Sticky\n");
+	seq_printf(p, "       ||+--- Locked\n");
+	seq_printf(p, "       |||+-- Exclusive\n");
+	seq_printf(p, "       ||||+- Virtual\n");
+	seq_printf(p, "[IRQ]  |||||\n");
+
+	mutex_lock(&ipd->mutex);
+
+	for (irq = 0; irq < IPIPE_NR_IRQS; irq++) {
+		/* Remember to protect against
+		 * ipipe_virtual_irq/ipipe_control_irq if more fields
+		 * get involved. */
+		ctlbits = ipd->irqs[irq].control;
+
+		if (irq >= IPIPE_NR_XIRQS && !ipipe_virtual_irq_p(irq))
+			/*
+			 * There might be a hole between the last external
+			 * IRQ and the first virtual one; skip it.
+			 */
+			continue;
+
+		if (ipipe_virtual_irq_p(irq)
+		    && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map))
+			/* Non-allocated virtual IRQ; skip it. */
+			continue;
+
+		/*
+		 * Statuses are as follows:
+		 * o "accepted" means handled _and_ passed down the pipeline.
+		 * o "grabbed" means handled, but the interrupt might be
+		 * terminated _or_ passed down the pipeline depending on
+		 * what the domain handler asks for to the I-pipe.
+		 * o "wired" is basically the same as "grabbed", except that
+		 * the interrupt is unconditionally delivered to an invariant
+		 * pipeline head domain.
+		 * o "passed" means unhandled by the domain but passed
+		 * down the pipeline.
+		 * o "discarded" means unhandled and _not_ passed down the
+		 * pipeline. The interrupt merely disappears from the
+		 * current domain down to the end of the pipeline.
+		 */
+		if (ctlbits & IPIPE_HANDLE_MASK) {
+			if (ctlbits & IPIPE_PASS_MASK)
+				handling = 'A';
+			else if (ctlbits & IPIPE_WIRED_MASK)
+				handling = 'W';
+			else
+				handling = 'G';
+		} else if (ctlbits & IPIPE_PASS_MASK)
+			/* Do not output if no major action is taken. */
+			continue;
+		else
+			handling = 'D';
+
+		if (ctlbits & IPIPE_STICKY_MASK)
+			stickiness = 'S';
+		else
+			stickiness = '.';
+
+		if (ctlbits & IPIPE_LOCK_MASK)
+			lockbit = 'L';
+		else
+			lockbit = '.';
+
+		if (ctlbits & IPIPE_EXCLUSIVE_MASK)
+			exclusive = 'X';
+		else
+			exclusive = '.';
+
+		if (ipipe_virtual_irq_p(irq))
+			virtuality = 'V';
+		else
+			virtuality = '.';
+
+		seq_printf(p, " %3u:  %c%c%c%c%c\n",
+			     irq, handling, stickiness, lockbit, exclusive, virtuality);
+	}
+
+	seq_printf(p, "[Domain info]\n");
+
+	seq_printf(p, "id=0x%.8x\n", ipd->domid);
+
+	if (test_bit(IPIPE_AHEAD_FLAG,&ipd->flags))
+		seq_printf(p, "priority=topmost\n");
+	else
+		seq_printf(p, "priority=%d\n", ipd->priority);
+
+	mutex_unlock(&ipd->mutex);
+
+	return 0;
+}
+
+static int __ipipe_common_info_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, __ipipe_common_info_show, PROC_I(inode)->pde->data);
+}
+
+static struct file_operations __ipipe_info_proc_ops = {
+	.owner		= THIS_MODULE,
+	.open		= __ipipe_common_info_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+void __ipipe_add_domain_proc(struct ipipe_domain *ipd)
+{
+	struct proc_dir_entry *e = create_proc_entry(ipd->name, 0444, ipipe_proc_root);
+	if (e) {
+		e->proc_fops = &__ipipe_info_proc_ops;
+		e->data = (void*) ipd;
+	}
+}
+
+void __ipipe_remove_domain_proc(struct ipipe_domain *ipd)
+{
+	remove_proc_entry(ipd->name,ipipe_proc_root);
+}
+
+void __init ipipe_init_proc(void)
+{
+	ipipe_proc_root = create_proc_entry("ipipe",S_IFDIR, 0);
+	create_proc_read_entry("version",0444,ipipe_proc_root,&__ipipe_version_info_proc,NULL);
+	__ipipe_add_domain_proc(ipipe_root_domain);
+
+	__ipipe_init_tracer();
+}
+
+#endif	/* CONFIG_PROC_FS */
+
+#ifdef CONFIG_IPIPE_DEBUG_CONTEXT
+
+DEFINE_PER_CPU(int, ipipe_percpu_context_check) = { 1 };
+DEFINE_PER_CPU(int, ipipe_saved_context_check_state);
+
+void ipipe_check_context(struct ipipe_domain *border_ipd)
+{
+	/* Note: We don't make the per_cpu access atomic. We assume that code
+	   which temporarily disables the check does this in atomic context
+	   only. */
+	if (likely(ipipe_current_domain->priority <= border_ipd->priority &&
+		   !test_bit(IPIPE_STALL_FLAG,
+			     &ipipe_head_cpudom_var(status))) ||
+	    !per_cpu(ipipe_percpu_context_check, ipipe_processor_id()))
+		return;
+
+	ipipe_context_check_off();
+
+	ipipe_trace_panic_freeze();
+	ipipe_set_printk_sync(ipipe_current_domain);
+
+	if (ipipe_current_domain->priority > border_ipd->priority)
+		printk(KERN_ERR "I-pipe: Detected illicit call from domain "
+				"'%s'\n"
+		       KERN_ERR "        into a service reserved for domain "
+				"'%s' and below.\n",
+		       ipipe_current_domain->name, border_ipd->name);
+	else
+		printk(KERN_ERR "I-pipe: Detected stalled topmost domain, "
+				"probably caused by a bug.\n"
+				"        A critical section may have been "
+				"left unterminated.\n");
+	dump_stack();
+	ipipe_trace_panic_dump();
+}
+
+EXPORT_SYMBOL(ipipe_check_context);
+#endif /* CONFIG_IPIPE_DEBUG_CONTEXT */
+
+EXPORT_SYMBOL(ipipe_virtualize_irq);
+EXPORT_SYMBOL(ipipe_control_irq);
+EXPORT_SYMBOL(ipipe_suspend_domain);
+EXPORT_SYMBOL(ipipe_alloc_virq);
+EXPORT_PER_CPU_SYMBOL(ipipe_percpu_domain);
+EXPORT_PER_CPU_SYMBOL(ipipe_percpu_darray);
+EXPORT_SYMBOL(ipipe_root);
+EXPORT_SYMBOL(ipipe_stall_pipeline_from);
+EXPORT_SYMBOL(ipipe_test_and_stall_pipeline_from);
+EXPORT_SYMBOL(ipipe_unstall_pipeline_from);
+EXPORT_SYMBOL(ipipe_restore_pipeline_from);
+EXPORT_SYMBOL(ipipe_test_and_unstall_pipeline_from);
+EXPORT_SYMBOL(ipipe_unstall_pipeline_head);
+EXPORT_SYMBOL(__ipipe_restore_pipeline_head);
+EXPORT_SYMBOL(__ipipe_unstall_root);
+EXPORT_SYMBOL(__ipipe_restore_root);
+EXPORT_SYMBOL(__ipipe_spin_lock_irq);
+EXPORT_SYMBOL(__ipipe_spin_unlock_irq);
+EXPORT_SYMBOL(__ipipe_spin_lock_irqsave);
+EXPORT_SYMBOL(__ipipe_spin_unlock_irqrestore);
+EXPORT_SYMBOL(__ipipe_pipeline);
+EXPORT_SYMBOL(__ipipe_lock_irq);
+EXPORT_SYMBOL(__ipipe_unlock_irq);
+EXPORT_SYMBOL(ipipe_register_domain);
+EXPORT_SYMBOL(ipipe_unregister_domain);
+EXPORT_SYMBOL(ipipe_free_virq);
+EXPORT_SYMBOL(ipipe_init_attr);
+EXPORT_SYMBOL(ipipe_catch_event);
+EXPORT_SYMBOL(ipipe_alloc_ptdkey);
+EXPORT_SYMBOL(ipipe_free_ptdkey);
+EXPORT_SYMBOL(ipipe_set_ptd);
+EXPORT_SYMBOL(ipipe_get_ptd);
+EXPORT_SYMBOL(ipipe_set_irq_affinity);
+EXPORT_SYMBOL(ipipe_send_ipi);
+EXPORT_SYMBOL(__ipipe_pend_irq);
+EXPORT_SYMBOL(__ipipe_set_irq_pending);
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+EXPORT_SYMBOL(ipipe_request_tickdev);
+EXPORT_SYMBOL(ipipe_release_tickdev);
+#endif
+
+EXPORT_SYMBOL(ipipe_critical_enter);
+EXPORT_SYMBOL(ipipe_critical_exit);
+EXPORT_SYMBOL(ipipe_trigger_irq);
+EXPORT_SYMBOL(ipipe_get_sysinfo);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/ipipe/tracer.c b/kernel/ipipe/tracer.c
new file mode 100644
index 0000000..2569659
--- /dev/null
+++ b/kernel/ipipe/tracer.c
@@ -0,0 +1,1384 @@
+/* -*- linux-c -*-
+ * kernel/ipipe/tracer.c
+ *
+ * Copyright (C) 2005 Luotao Fu.
+ *               2005-2008 Jan Kiszka.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ * USA; either version 2 of the License, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/ctype.h>
+#include <linux/vmalloc.h>
+#include <linux/pid.h>
+#include <linux/utsrelease.h>
+#include <linux/sched.h>
+#include <linux/ipipe.h>
+#include <asm/uaccess.h>
+
+#define IPIPE_TRACE_PATHS           4 /* <!> Do not lower below 3 */
+#define IPIPE_DEFAULT_ACTIVE        0
+#define IPIPE_DEFAULT_MAX           1
+#define IPIPE_DEFAULT_FROZEN        2
+
+#define IPIPE_TRACE_POINTS          (1 << CONFIG_IPIPE_TRACE_SHIFT)
+#define WRAP_POINT_NO(point)        ((point) & (IPIPE_TRACE_POINTS-1))
+
+#define IPIPE_DEFAULT_PRE_TRACE     10
+#define IPIPE_DEFAULT_POST_TRACE    10
+#define IPIPE_DEFAULT_BACK_TRACE    1024
+
+#define IPIPE_DELAY_NOTE            1000  /* in nanoseconds */
+#define IPIPE_DELAY_WARN            10000 /* in nanoseconds */
+
+#define IPIPE_TFLG_NMI_LOCK         0x0001
+#define IPIPE_TFLG_NMI_HIT          0x0002
+#define IPIPE_TFLG_NMI_FREEZE_REQ   0x0004
+
+#define IPIPE_TFLG_HWIRQ_OFF        0x0100
+#define IPIPE_TFLG_FREEZING         0x0200
+#define IPIPE_TFLG_CURRDOM_SHIFT    10   /* bits 10..11: current domain */
+#define IPIPE_TFLG_CURRDOM_MASK     0x0C00
+#define IPIPE_TFLG_DOMSTATE_SHIFT   12   /* bits 12..15: domain stalled? */
+#define IPIPE_TFLG_DOMSTATE_BITS    3
+
+#define IPIPE_TFLG_DOMAIN_STALLED(point, n) \
+	(point->flags & (1 << (n + IPIPE_TFLG_DOMSTATE_SHIFT)))
+#define IPIPE_TFLG_CURRENT_DOMAIN(point) \
+	((point->flags & IPIPE_TFLG_CURRDOM_MASK) >> IPIPE_TFLG_CURRDOM_SHIFT)
+
+struct ipipe_trace_point {
+	short type;
+	short flags;
+	unsigned long eip;
+	unsigned long parent_eip;
+	unsigned long v;
+	unsigned long long timestamp;
+};
+
+struct ipipe_trace_path {
+	volatile int flags;
+	int dump_lock; /* separated from flags due to cross-cpu access */
+	int trace_pos; /* next point to fill */
+	int begin, end; /* finalised path begin and end */
+	int post_trace; /* non-zero when in post-trace phase */
+	unsigned long long length; /* max path length in cycles */
+	unsigned long nmi_saved_eip; /* for deferred requests from NMIs */
+	unsigned long nmi_saved_parent_eip;
+	unsigned long nmi_saved_v;
+	struct ipipe_trace_point point[IPIPE_TRACE_POINTS];
+} ____cacheline_aligned_in_smp;
+
+enum ipipe_trace_type
+{
+	IPIPE_TRACE_FUNC = 0,
+	IPIPE_TRACE_BEGIN,
+	IPIPE_TRACE_END,
+	IPIPE_TRACE_FREEZE,
+	IPIPE_TRACE_SPECIAL,
+	IPIPE_TRACE_PID,
+	IPIPE_TRACE_EVENT,
+};
+
+#define IPIPE_TYPE_MASK             0x0007
+#define IPIPE_TYPE_BITS             3
+
+#ifdef CONFIG_IPIPE_TRACE_VMALLOC
+static DEFINE_PER_CPU(struct ipipe_trace_path *, trace_path);
+#else /* !CONFIG_IPIPE_TRACE_VMALLOC */
+static DEFINE_PER_CPU(struct ipipe_trace_path, trace_path[IPIPE_TRACE_PATHS]) =
+	{ [0 ... IPIPE_TRACE_PATHS-1] = { .begin = -1, .end = -1 } };
+#endif /* CONFIG_IPIPE_TRACE_VMALLOC */
+
+int ipipe_trace_enable = 0;
+
+static DEFINE_PER_CPU(int, active_path) = { IPIPE_DEFAULT_ACTIVE };
+static DEFINE_PER_CPU(int, max_path) = { IPIPE_DEFAULT_MAX };
+static DEFINE_PER_CPU(int, frozen_path) = { IPIPE_DEFAULT_FROZEN };
+static IPIPE_DEFINE_SPINLOCK(global_path_lock);
+static int pre_trace = IPIPE_DEFAULT_PRE_TRACE;
+static int post_trace = IPIPE_DEFAULT_POST_TRACE;
+static int back_trace = IPIPE_DEFAULT_BACK_TRACE;
+static int verbose_trace = 1;
+static unsigned long trace_overhead;
+
+static unsigned long trigger_begin;
+static unsigned long trigger_end;
+
+static DEFINE_MUTEX(out_mutex);
+static struct ipipe_trace_path *print_path;
+#ifdef CONFIG_IPIPE_TRACE_PANIC
+static struct ipipe_trace_path *panic_path;
+#endif /* CONFIG_IPIPE_TRACE_PANIC */
+static int print_pre_trace;
+static int print_post_trace;
+
+
+static long __ipipe_signed_tsc2us(long long tsc);
+static void
+__ipipe_trace_point_type(char *buf, struct ipipe_trace_point *point);
+static void __ipipe_print_symname(struct seq_file *m, unsigned long eip);
+
+
+static notrace void
+__ipipe_store_domain_states(struct ipipe_trace_point *point)
+{
+	struct ipipe_domain *ipd;
+	struct list_head *pos;
+	int i = 0;
+
+	list_for_each_prev(pos, &__ipipe_pipeline) {
+		ipd = list_entry(pos, struct ipipe_domain, p_link);
+
+		if (test_bit(IPIPE_STALL_FLAG, &ipipe_cpudom_var(ipd, status)))
+			point->flags |= 1 << (i + IPIPE_TFLG_DOMSTATE_SHIFT);
+
+		if (ipd == ipipe_current_domain)
+			point->flags |= i << IPIPE_TFLG_CURRDOM_SHIFT;
+
+		if (++i > IPIPE_TFLG_DOMSTATE_BITS)
+			break;
+	}
+}
+
+static notrace int __ipipe_get_free_trace_path(int old, int cpu)
+{
+	int new_active = old;
+	struct ipipe_trace_path *tp;
+
+	do {
+		if (++new_active == IPIPE_TRACE_PATHS)
+			new_active = 0;
+		tp = &per_cpu(trace_path, cpu)[new_active];
+	} while (new_active == per_cpu(max_path, cpu) ||
+	         new_active == per_cpu(frozen_path, cpu) ||
+	         tp->dump_lock);
+
+	return new_active;
+}
+
+static notrace void
+__ipipe_migrate_pre_trace(struct ipipe_trace_path *new_tp,
+                          struct ipipe_trace_path *old_tp, int old_pos)
+{
+	int i;
+
+	new_tp->trace_pos = pre_trace+1;
+
+	for (i = new_tp->trace_pos; i > 0; i--)
+		memcpy(&new_tp->point[WRAP_POINT_NO(new_tp->trace_pos-i)],
+		       &old_tp->point[WRAP_POINT_NO(old_pos-i)],
+		       sizeof(struct ipipe_trace_point));
+
+	/* mark the end (i.e. the point before point[0]) invalid */
+	new_tp->point[IPIPE_TRACE_POINTS-1].eip = 0;
+}
+
+static notrace struct ipipe_trace_path *
+__ipipe_trace_end(int cpu, struct ipipe_trace_path *tp, int pos)
+{
+	struct ipipe_trace_path *old_tp = tp;
+	long active = per_cpu(active_path, cpu);
+	unsigned long long length;
+
+	/* do we have a new worst case? */
+	length = tp->point[tp->end].timestamp -
+	         tp->point[tp->begin].timestamp;
+	if (length > per_cpu(trace_path, cpu)[per_cpu(max_path, cpu)].length) {
+		/* we need protection here against other cpus trying
+		   to start a proc dump */
+		spin_lock(&global_path_lock);
+
+		/* active path holds new worst case */
+		tp->length = length;
+		per_cpu(max_path, cpu) = active;
+
+		/* find next unused trace path */
+		active = __ipipe_get_free_trace_path(active, cpu);
+
+		spin_unlock(&global_path_lock);
+
+		tp = &per_cpu(trace_path, cpu)[active];
+
+		/* migrate last entries for pre-tracing */
+		__ipipe_migrate_pre_trace(tp, old_tp, pos);
+	}
+
+	return tp;
+}
+
+static notrace struct ipipe_trace_path *
+__ipipe_trace_freeze(int cpu, struct ipipe_trace_path *tp, int pos)
+{
+	struct ipipe_trace_path *old_tp = tp;
+	long active = per_cpu(active_path, cpu);
+	int n;
+
+	/* frozen paths have no core (begin=end) */
+	tp->begin = tp->end;
+
+	/* we need protection here against other cpus trying
+	 * to set their frozen path or to start a proc dump */
+	spin_lock(&global_path_lock);
+
+	per_cpu(frozen_path, cpu) = active;
+
+	/* find next unused trace path */
+	active = __ipipe_get_free_trace_path(active, cpu);
+
+	/* check if this is the first frozen path */
+	for_each_possible_cpu(n) {
+		if (n != cpu &&
+		    per_cpu(trace_path, n)[per_cpu(frozen_path, n)].end >= 0)
+			tp->end = -1;
+	}
+
+	spin_unlock(&global_path_lock);
+
+	tp = &per_cpu(trace_path, cpu)[active];
+
+	/* migrate last entries for pre-tracing */
+	__ipipe_migrate_pre_trace(tp, old_tp, pos);
+
+	return tp;
+}
+
+void notrace
+__ipipe_trace(enum ipipe_trace_type type, unsigned long eip,
+              unsigned long parent_eip, unsigned long v)
+{
+	struct ipipe_trace_path *tp, *old_tp;
+	int pos, next_pos, begin;
+	struct ipipe_trace_point *point;
+	unsigned long flags;
+	int cpu;
+
+	local_irq_save_hw_notrace(flags);
+
+	cpu = ipipe_processor_id();
+ restart:
+	tp = old_tp = &per_cpu(trace_path, cpu)[per_cpu(active_path, cpu)];
+
+	/* here starts a race window with NMIs - catched below */
+
+	/* check for NMI recursion */
+	if (unlikely(tp->flags & IPIPE_TFLG_NMI_LOCK)) {
+		tp->flags |= IPIPE_TFLG_NMI_HIT;
+
+		/* first freeze request from NMI context? */
+		if ((type == IPIPE_TRACE_FREEZE) &&
+		    !(tp->flags & IPIPE_TFLG_NMI_FREEZE_REQ)) {
+			/* save arguments and mark deferred freezing */
+			tp->flags |= IPIPE_TFLG_NMI_FREEZE_REQ;
+			tp->nmi_saved_eip = eip;
+			tp->nmi_saved_parent_eip = parent_eip;
+			tp->nmi_saved_v = v;
+		}
+		return; /* no need for restoring flags inside IRQ */
+	}
+
+	/* clear NMI events and set lock (atomically per cpu) */
+	tp->flags = (tp->flags & ~(IPIPE_TFLG_NMI_HIT |
+	                           IPIPE_TFLG_NMI_FREEZE_REQ))
+	                       | IPIPE_TFLG_NMI_LOCK;
+
+	/* check active_path again - some nasty NMI may have switched
+	 * it meanwhile */
+	if (unlikely(tp !=
+		     &per_cpu(trace_path, cpu)[per_cpu(active_path, cpu)])) {
+		/* release lock on wrong path and restart */
+		tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+
+		/* there is no chance that the NMI got deferred
+		 * => no need to check for pending freeze requests */
+		goto restart;
+	}
+
+	/* get the point buffer */
+	pos = tp->trace_pos;
+	point = &tp->point[pos];
+
+	/* store all trace point data */
+	point->type = type;
+	point->flags = raw_irqs_disabled_flags(flags) ? IPIPE_TFLG_HWIRQ_OFF : 0;
+	point->eip = eip;
+	point->parent_eip = parent_eip;
+	point->v = v;
+	ipipe_read_tsc(point->timestamp);
+
+	__ipipe_store_domain_states(point);
+
+	/* forward to next point buffer */
+	next_pos = WRAP_POINT_NO(pos+1);
+	tp->trace_pos = next_pos;
+
+	/* only mark beginning if we haven't started yet */
+	begin = tp->begin;
+	if (unlikely(type == IPIPE_TRACE_BEGIN) && (begin < 0))
+		tp->begin = pos;
+
+	/* end of critical path, start post-trace if not already started */
+	if (unlikely(type == IPIPE_TRACE_END) &&
+	    (begin >= 0) && !tp->post_trace)
+		tp->post_trace = post_trace + 1;
+
+	/* freeze only if the slot is free and we are not already freezing */
+	if ((unlikely(type == IPIPE_TRACE_FREEZE) ||
+	     (unlikely(eip >= trigger_begin && eip <= trigger_end) &&
+	     type == IPIPE_TRACE_FUNC)) &&
+	    per_cpu(trace_path, cpu)[per_cpu(frozen_path, cpu)].begin < 0 &&
+	    !(tp->flags & IPIPE_TFLG_FREEZING)) {
+		tp->post_trace = post_trace + 1;
+		tp->flags |= IPIPE_TFLG_FREEZING;
+	}
+
+	/* enforce end of trace in case of overflow */
+	if (unlikely(WRAP_POINT_NO(next_pos + 1) == begin)) {
+		tp->end = pos;
+		goto enforce_end;
+	}
+
+	/* stop tracing this path if we are in post-trace and
+	 *  a) that phase is over now or
+	 *  b) a new TRACE_BEGIN came in but we are not freezing this path */
+	if (unlikely((tp->post_trace > 0) && ((--tp->post_trace == 0) ||
+	             ((type == IPIPE_TRACE_BEGIN) &&
+	              !(tp->flags & IPIPE_TFLG_FREEZING))))) {
+		/* store the path's end (i.e. excluding post-trace) */
+		tp->end = WRAP_POINT_NO(pos - post_trace + tp->post_trace);
+
+ enforce_end:
+		if (tp->flags & IPIPE_TFLG_FREEZING)
+			tp = __ipipe_trace_freeze(cpu, tp, pos);
+		else
+			tp = __ipipe_trace_end(cpu, tp, pos);
+
+		/* reset the active path, maybe already start a new one */
+		tp->begin = (type == IPIPE_TRACE_BEGIN) ?
+			WRAP_POINT_NO(tp->trace_pos - 1) : -1;
+		tp->end = -1;
+		tp->post_trace = 0;
+		tp->flags = 0;
+
+		/* update active_path not earlier to avoid races with NMIs */
+		per_cpu(active_path, cpu) = tp - per_cpu(trace_path, cpu);
+	}
+
+	/* we still have old_tp and point,
+	 * let's reset NMI lock and check for catches */
+	old_tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+	if (unlikely(old_tp->flags & IPIPE_TFLG_NMI_HIT)) {
+		/* well, this late tagging may not immediately be visible for
+		 * other cpus already dumping this path - a minor issue */
+		point->flags |= IPIPE_TFLG_NMI_HIT;
+
+		/* handle deferred freezing from NMI context */
+		if (old_tp->flags & IPIPE_TFLG_NMI_FREEZE_REQ)
+			__ipipe_trace(IPIPE_TRACE_FREEZE, old_tp->nmi_saved_eip,
+			              old_tp->nmi_saved_parent_eip,
+			              old_tp->nmi_saved_v);
+	}
+
+	local_irq_restore_hw_notrace(flags);
+}
+
+static unsigned long __ipipe_global_path_lock(void)
+{
+	unsigned long flags;
+	int cpu;
+	struct ipipe_trace_path *tp;
+
+	spin_lock_irqsave(&global_path_lock, flags);
+
+	cpu = ipipe_processor_id();
+ restart:
+	tp = &per_cpu(trace_path, cpu)[per_cpu(active_path, cpu)];
+
+	/* here is small race window with NMIs - catched below */
+
+	/* clear NMI events and set lock (atomically per cpu) */
+	tp->flags = (tp->flags & ~(IPIPE_TFLG_NMI_HIT |
+	                           IPIPE_TFLG_NMI_FREEZE_REQ))
+	                       | IPIPE_TFLG_NMI_LOCK;
+
+	/* check active_path again - some nasty NMI may have switched
+	 * it meanwhile */
+	if (tp != &per_cpu(trace_path, cpu)[per_cpu(active_path, cpu)]) {
+		/* release lock on wrong path and restart */
+		tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+
+		/* there is no chance that the NMI got deferred
+		 * => no need to check for pending freeze requests */
+		goto restart;
+	}
+
+	return flags;
+}
+
+static void __ipipe_global_path_unlock(unsigned long flags)
+{
+	int cpu;
+	struct ipipe_trace_path *tp;
+
+	/* release spinlock first - it's not involved in the NMI issue */
+	__ipipe_spin_unlock_irqbegin(&global_path_lock);
+
+	cpu = ipipe_processor_id();
+	tp = &per_cpu(trace_path, cpu)[per_cpu(active_path, cpu)];
+
+	tp->flags &= ~IPIPE_TFLG_NMI_LOCK;
+
+	/* handle deferred freezing from NMI context */
+	if (tp->flags & IPIPE_TFLG_NMI_FREEZE_REQ)
+		__ipipe_trace(IPIPE_TRACE_FREEZE, tp->nmi_saved_eip,
+		              tp->nmi_saved_parent_eip, tp->nmi_saved_v);
+
+	/* See __ipipe_spin_lock_irqsave() and friends. */
+	__ipipe_spin_unlock_irqcomplete(flags);
+}
+
+void notrace ipipe_trace_begin(unsigned long v)
+{
+	if (!ipipe_trace_enable)
+		return;
+	__ipipe_trace(IPIPE_TRACE_BEGIN, __BUILTIN_RETURN_ADDRESS0,
+	              __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_begin);
+
+void notrace ipipe_trace_end(unsigned long v)
+{
+	if (!ipipe_trace_enable)
+		return;
+	__ipipe_trace(IPIPE_TRACE_END, __BUILTIN_RETURN_ADDRESS0,
+	              __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_end);
+
+void notrace ipipe_trace_freeze(unsigned long v)
+{
+	if (!ipipe_trace_enable)
+		return;
+	__ipipe_trace(IPIPE_TRACE_FREEZE, __BUILTIN_RETURN_ADDRESS0,
+	              __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_freeze);
+
+void notrace ipipe_trace_special(unsigned char id, unsigned long v)
+{
+	if (!ipipe_trace_enable)
+		return;
+	__ipipe_trace(IPIPE_TRACE_SPECIAL | (id << IPIPE_TYPE_BITS),
+	              __BUILTIN_RETURN_ADDRESS0,
+	              __BUILTIN_RETURN_ADDRESS1, v);
+}
+EXPORT_SYMBOL(ipipe_trace_special);
+
+void notrace ipipe_trace_pid(pid_t pid, short prio)
+{
+	if (!ipipe_trace_enable)
+		return;
+	__ipipe_trace(IPIPE_TRACE_PID | (prio << IPIPE_TYPE_BITS),
+	              __BUILTIN_RETURN_ADDRESS0,
+	              __BUILTIN_RETURN_ADDRESS1, pid);
+}
+EXPORT_SYMBOL(ipipe_trace_pid);
+
+void notrace ipipe_trace_event(unsigned char id, unsigned long delay_tsc)
+{
+	if (!ipipe_trace_enable)
+		return;
+	__ipipe_trace(IPIPE_TRACE_EVENT | (id << IPIPE_TYPE_BITS),
+	              __BUILTIN_RETURN_ADDRESS0,
+	              __BUILTIN_RETURN_ADDRESS1, delay_tsc);
+}
+EXPORT_SYMBOL(ipipe_trace_event);
+
+int ipipe_trace_max_reset(void)
+{
+	int cpu;
+	unsigned long flags;
+	struct ipipe_trace_path *path;
+	int ret = 0;
+
+	flags = __ipipe_global_path_lock();
+
+	for_each_possible_cpu(cpu) {
+		path = &per_cpu(trace_path, cpu)[per_cpu(max_path, cpu)];
+
+		if (path->dump_lock) {
+			ret = -EBUSY;
+			break;
+		}
+
+		path->begin     = -1;
+		path->end       = -1;
+		path->trace_pos = 0;
+		path->length    = 0;
+	}
+
+	__ipipe_global_path_unlock(flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(ipipe_trace_max_reset);
+
+int ipipe_trace_frozen_reset(void)
+{
+	int cpu;
+	unsigned long flags;
+	struct ipipe_trace_path *path;
+	int ret = 0;
+
+	flags = __ipipe_global_path_lock();
+
+	for_each_online_cpu(cpu) {
+		path = &per_cpu(trace_path, cpu)[per_cpu(frozen_path, cpu)];
+
+		if (path->dump_lock) {
+			ret = -EBUSY;
+			break;
+		}
+
+		path->begin = -1;
+		path->end = -1;
+		path->trace_pos = 0;
+		path->length    = 0;
+	}
+
+	__ipipe_global_path_unlock(flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(ipipe_trace_frozen_reset);
+
+static void
+__ipipe_get_task_info(char *task_info, struct ipipe_trace_point *point,
+                      int trylock)
+{
+	struct task_struct *task = NULL;
+	char buf[8];
+	int i;
+	int locked = 1;
+
+	if (trylock) {
+		if (!read_trylock(&tasklist_lock))
+			locked = 0;
+	} else
+		read_lock(&tasklist_lock);
+
+	if (locked)
+		task = find_task_by_pid_type_ns(PIDTYPE_PID, (pid_t)point->v, &init_pid_ns);
+
+	if (task)
+		strncpy(task_info, task->comm, 11);
+	else
+		strcpy(task_info, "-<?>-");
+
+	if (locked)
+		read_unlock(&tasklist_lock);
+
+	for (i = strlen(task_info); i < 11; i++)
+		task_info[i] = ' ';
+
+	sprintf(buf, " %d ", point->type >> IPIPE_TYPE_BITS);
+	strcpy(task_info + (11 - strlen(buf)), buf);
+}
+
+static void
+__ipipe_get_event_date(char *buf,struct ipipe_trace_path *path,
+		       struct ipipe_trace_point *point)
+{
+	long time;
+	int type;
+
+	time = __ipipe_signed_tsc2us(point->timestamp -
+				     path->point[path->begin].timestamp + point->v);
+	type = point->type >> IPIPE_TYPE_BITS;
+
+	if (type == 0)
+		/*
+		 * Event type #0 is predefined, stands for the next
+		 * timer tick.
+		 */
+		sprintf(buf, "tick@%-6ld", time);
+	else
+		sprintf(buf, "%3d@%-7ld", type, time);
+}
+
+#ifdef CONFIG_IPIPE_TRACE_PANIC
+void ipipe_trace_panic_freeze(void)
+{
+	unsigned long flags;
+	int cpu;
+
+	if (!ipipe_trace_enable)
+		return;
+
+	ipipe_trace_enable = 0;
+	local_irq_save_hw_notrace(flags);
+
+	cpu = ipipe_processor_id();
+
+	panic_path = &per_cpu(trace_path, cpu)[per_cpu(active_path, cpu)];
+
+	local_irq_restore_hw(flags);
+}
+EXPORT_SYMBOL(ipipe_trace_panic_freeze);
+
+void ipipe_trace_panic_dump(void)
+{
+	int cnt = back_trace;
+	int start, pos;
+	char buf[16];
+
+	if (!panic_path)
+		return;
+
+	ipipe_context_check_off();
+
+	printk("I-pipe tracer log (%d points):\n", cnt);
+
+	start = pos = WRAP_POINT_NO(panic_path->trace_pos-1);
+
+	while (cnt-- > 0) {
+		struct ipipe_trace_point *point = &panic_path->point[pos];
+		long time;
+		char info[16];
+		int i;
+
+		printk(" %c",
+		       (point->flags & IPIPE_TFLG_HWIRQ_OFF) ? '|' : ' ');
+
+		for (i = IPIPE_TFLG_DOMSTATE_BITS; i >= 0; i--)
+			printk("%c",
+			       (IPIPE_TFLG_CURRENT_DOMAIN(point) == i) ?
+				(IPIPE_TFLG_DOMAIN_STALLED(point, i) ?
+					'#' : '+') :
+				(IPIPE_TFLG_DOMAIN_STALLED(point, i) ?
+					'*' : ' '));
+
+		if (!point->eip)
+			printk("-<invalid>-\n");
+		else {
+			__ipipe_trace_point_type(buf, point);
+			printk("%s", buf);
+
+			switch (point->type & IPIPE_TYPE_MASK) {
+				case IPIPE_TRACE_FUNC:
+					printk("           ");
+					break;
+
+				case IPIPE_TRACE_PID:
+					__ipipe_get_task_info(info,
+							      point, 1);
+					printk(info);
+					break;
+
+				case IPIPE_TRACE_EVENT:
+					__ipipe_get_event_date(info,
+							       panic_path, point);
+					printk("%s", info);
+					break;
+
+				default:
+					printk("0x%08lx ", point->v);
+			}
+
+			time = __ipipe_signed_tsc2us(point->timestamp -
+				panic_path->point[start].timestamp);
+			printk(" %5ld ", time);
+
+			__ipipe_print_symname(NULL, point->eip);
+			printk(" (");
+			__ipipe_print_symname(NULL, point->parent_eip);
+			printk(")\n");
+		}
+		pos = WRAP_POINT_NO(pos - 1);
+	}
+
+	panic_path = NULL;
+}
+EXPORT_SYMBOL(ipipe_trace_panic_dump);
+#endif /* CONFIG_IPIPE_TRACE_PANIC */
+
+
+/* --- /proc output --- */
+
+static notrace int __ipipe_in_critical_trpath(long point_no)
+{
+	return ((WRAP_POINT_NO(point_no-print_path->begin) <
+	         WRAP_POINT_NO(print_path->end-print_path->begin)) ||
+	        ((print_path->end == print_path->begin) &&
+	         (WRAP_POINT_NO(point_no-print_path->end) >
+	          print_post_trace)));
+}
+
+static long __ipipe_signed_tsc2us(long long tsc)
+{
+        unsigned long long abs_tsc;
+        long us;
+
+	/* ipipe_tsc2us works on unsigned => handle sign separately */
+        abs_tsc = (tsc >= 0) ? tsc : -tsc;
+        us = ipipe_tsc2us(abs_tsc);
+        if (tsc < 0)
+                return -us;
+        else
+                return us;
+}
+
+static void
+__ipipe_trace_point_type(char *buf, struct ipipe_trace_point *point)
+{
+	switch (point->type & IPIPE_TYPE_MASK) {
+		case IPIPE_TRACE_FUNC:
+			strcpy(buf, "func    ");
+			break;
+
+		case IPIPE_TRACE_BEGIN:
+			strcpy(buf, "begin   ");
+			break;
+
+		case IPIPE_TRACE_END:
+			strcpy(buf, "end     ");
+			break;
+
+		case IPIPE_TRACE_FREEZE:
+			strcpy(buf, "freeze  ");
+			break;
+
+		case IPIPE_TRACE_SPECIAL:
+			sprintf(buf, "(0x%02x)  ",
+				point->type >> IPIPE_TYPE_BITS);
+			break;
+
+		case IPIPE_TRACE_PID:
+			sprintf(buf, "[%5d] ", (pid_t)point->v);
+			break;
+
+		case IPIPE_TRACE_EVENT:
+			sprintf(buf, "event   ");
+			break;
+	}
+}
+
+static void
+__ipipe_print_pathmark(struct seq_file *m, struct ipipe_trace_point *point)
+{
+	char mark = ' ';
+	int point_no = point - print_path->point;
+	int i;
+
+	if (print_path->end == point_no)
+		mark = '<';
+	else if (print_path->begin == point_no)
+		mark = '>';
+	else if (__ipipe_in_critical_trpath(point_no))
+		mark = ':';
+	seq_printf(m, "%c%c", mark,
+	           (point->flags & IPIPE_TFLG_HWIRQ_OFF) ? '|' : ' ');
+
+	if (!verbose_trace)
+		return;
+
+	for (i = IPIPE_TFLG_DOMSTATE_BITS; i >= 0; i--)
+		seq_printf(m, "%c",
+			(IPIPE_TFLG_CURRENT_DOMAIN(point) == i) ?
+			    (IPIPE_TFLG_DOMAIN_STALLED(point, i) ?
+				'#' : '+') :
+			(IPIPE_TFLG_DOMAIN_STALLED(point, i) ? '*' : ' '));
+}
+
+static void
+__ipipe_print_delay(struct seq_file *m, struct ipipe_trace_point *point)
+{
+	unsigned long delay = 0;
+	int next;
+	char *mark = "  ";
+
+	next = WRAP_POINT_NO(point+1 - print_path->point);
+
+	if (next != print_path->trace_pos)
+		delay = ipipe_tsc2ns(print_path->point[next].timestamp -
+		                     point->timestamp);
+
+	if (__ipipe_in_critical_trpath(point - print_path->point)) {
+		if (delay > IPIPE_DELAY_WARN)
+			mark = "! ";
+		else if (delay > IPIPE_DELAY_NOTE)
+			mark = "+ ";
+	}
+	seq_puts(m, mark);
+
+	if (verbose_trace)
+		seq_printf(m, "%3lu.%03lu%c ", delay/1000, delay%1000,
+		           (point->flags & IPIPE_TFLG_NMI_HIT) ? 'N' : ' ');
+	else
+		seq_puts(m, " ");
+}
+
+static void __ipipe_print_symname(struct seq_file *m, unsigned long eip)
+{
+	char namebuf[KSYM_NAME_LEN+1];
+	unsigned long size, offset;
+	const char *sym_name;
+	char *modname;
+
+	sym_name = kallsyms_lookup(eip, &size, &offset, &modname, namebuf);
+
+#ifdef CONFIG_IPIPE_TRACE_PANIC
+	if (!m) {
+		/* panic dump */
+		if (sym_name) {
+			printk("%s+0x%lx", sym_name, offset);
+			if (modname)
+				printk(" [%s]", modname);
+		}
+	} else
+#endif /* CONFIG_IPIPE_TRACE_PANIC */
+	{
+		if (sym_name) {
+			if (verbose_trace) {
+				seq_printf(m, "%s+0x%lx", sym_name, offset);
+				if (modname)
+					seq_printf(m, " [%s]", modname);
+			} else
+				seq_puts(m, sym_name);
+		} else
+			seq_printf(m, "<%08lx>", eip);
+	}
+}
+
+static void __ipipe_print_headline(struct seq_file *m)
+{
+	seq_printf(m, "Calibrated minimum trace-point overhead: %lu.%03lu "
+		   "us\n\n", trace_overhead/1000, trace_overhead%1000);
+
+	if (verbose_trace) {
+		const char *name[4] = { [0 ... 3] = "<unused>" };
+		struct list_head *pos;
+		int i = 0;
+
+		list_for_each_prev(pos, &__ipipe_pipeline) {
+			struct ipipe_domain *ipd =
+				list_entry(pos, struct ipipe_domain, p_link);
+
+			name[i] = ipd->name;
+			if (++i > 3)
+				break;
+		}
+
+		seq_printf(m,
+		           " +----- Hard IRQs ('|': locked)\n"
+		           " |+---- %s\n"
+		           " ||+--- %s\n"
+		           " |||+-- %s\n"
+		           " ||||+- %s%s\n"
+		           " |||||                        +---------- "
+		               "Delay flag ('+': > %d us, '!': > %d us)\n"
+		           " |||||                        |        +- "
+		               "NMI noise ('N')\n"
+		           " |||||                        |        |\n"
+		           "      Type    User Val.   Time    Delay  Function "
+		               "(Parent)\n",
+		           name[3], name[2], name[1], name[0],
+		           name[0] ? " ('*': domain stalled, '+': current, "
+		               "'#': current+stalled)" : "",
+		           IPIPE_DELAY_NOTE/1000, IPIPE_DELAY_WARN/1000);
+	} else
+		seq_printf(m,
+		           " +--------------- Hard IRQs ('|': locked)\n"
+		           " |             +- Delay flag "
+		               "('+': > %d us, '!': > %d us)\n"
+		           " |             |\n"
+		           "  Type     Time   Function (Parent)\n",
+		           IPIPE_DELAY_NOTE/1000, IPIPE_DELAY_WARN/1000);
+}
+
+static void *__ipipe_max_prtrace_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t n = *pos;
+
+	mutex_lock(&out_mutex);
+
+	if (!n) {
+		struct ipipe_trace_path *tp;
+		unsigned long length_usecs;
+		int points, cpu;
+		unsigned long flags;
+
+		/* protect against max_path/frozen_path updates while we
+		 * haven't locked our target path, also avoid recursively
+		 * taking global_path_lock from NMI context */
+		flags = __ipipe_global_path_lock();
+
+		/* find the longest of all per-cpu paths */
+		print_path = NULL;
+		for_each_online_cpu(cpu) {
+			tp = &per_cpu(trace_path, cpu)[per_cpu(max_path, cpu)];
+			if ((print_path == NULL) ||
+			    (tp->length > print_path->length)) {
+				print_path = tp;
+				break;
+			}
+		}
+		print_path->dump_lock = 1;
+
+		__ipipe_global_path_unlock(flags);
+
+		/* does this path actually contain data? */
+		if (print_path->end == print_path->begin)
+			return NULL;
+
+		/* number of points inside the critical path */
+		points = WRAP_POINT_NO(print_path->end-print_path->begin+1);
+
+		/* pre- and post-tracing length, post-trace length was frozen
+		   in __ipipe_trace, pre-trace may have to be reduced due to
+		   buffer overrun */
+		print_pre_trace  = pre_trace;
+		print_post_trace = WRAP_POINT_NO(print_path->trace_pos -
+		                                 print_path->end - 1);
+		if (points+pre_trace+print_post_trace > IPIPE_TRACE_POINTS - 1)
+			print_pre_trace = IPIPE_TRACE_POINTS - 1 - points -
+				print_post_trace;
+
+		length_usecs = ipipe_tsc2us(print_path->length);
+		seq_printf(m, "I-pipe worst-case tracing service on %s/ipipe-%s\n"
+			"------------------------------------------------------------\n",
+			UTS_RELEASE, IPIPE_ARCH_STRING);
+		seq_printf(m, "CPU: %d, Begin: %lld cycles, Trace Points: "
+			"%d (-%d/+%d), Length: %lu us\n",
+			cpu, print_path->point[print_path->begin].timestamp,
+			points, print_pre_trace, print_post_trace, length_usecs);
+		__ipipe_print_headline(m);
+	}
+
+	/* check if we are inside the trace range */
+	if (n >= WRAP_POINT_NO(print_path->end - print_path->begin + 1 +
+	                       print_pre_trace + print_post_trace))
+		return NULL;
+
+	/* return the next point to be shown */
+	return &print_path->point[WRAP_POINT_NO(print_path->begin -
+	                                        print_pre_trace + n)];
+}
+
+static void *__ipipe_prtrace_next(struct seq_file *m, void *p, loff_t *pos)
+{
+	loff_t n = ++*pos;
+
+	/* check if we are inside the trace range with the next entry */
+	if (n >= WRAP_POINT_NO(print_path->end - print_path->begin + 1 +
+	                       print_pre_trace + print_post_trace))
+		return NULL;
+
+	/* return the next point to be shown */
+	return &print_path->point[WRAP_POINT_NO(print_path->begin -
+	                                        print_pre_trace + *pos)];
+}
+
+static void __ipipe_prtrace_stop(struct seq_file *m, void *p)
+{
+	if (print_path)
+		print_path->dump_lock = 0;
+	mutex_unlock(&out_mutex);
+}
+
+static int __ipipe_prtrace_show(struct seq_file *m, void *p)
+{
+	long time;
+	struct ipipe_trace_point *point = p;
+	char buf[16];
+
+	if (!point->eip) {
+		seq_puts(m, "-<invalid>-\n");
+		return 0;
+	}
+
+	__ipipe_print_pathmark(m, point);
+	__ipipe_trace_point_type(buf, point);
+	seq_puts(m, buf);
+	if (verbose_trace)
+		switch (point->type & IPIPE_TYPE_MASK) {
+			case IPIPE_TRACE_FUNC:
+				seq_puts(m, "           ");
+				break;
+
+			case IPIPE_TRACE_PID:
+				__ipipe_get_task_info(buf, point, 0);
+				seq_puts(m, buf);
+				break;
+
+			case IPIPE_TRACE_EVENT:
+				__ipipe_get_event_date(buf, print_path, point);
+				seq_puts(m, buf);
+				break;
+
+			default:
+				seq_printf(m, "0x%08lx ", point->v);
+		}
+
+	time = __ipipe_signed_tsc2us(point->timestamp -
+		print_path->point[print_path->begin].timestamp);
+	seq_printf(m, "%5ld", time);
+
+	__ipipe_print_delay(m, point);
+	__ipipe_print_symname(m, point->eip);
+	seq_puts(m, " (");
+	__ipipe_print_symname(m, point->parent_eip);
+	seq_puts(m, ")\n");
+
+	return 0;
+}
+
+static struct seq_operations __ipipe_max_ptrace_ops = {
+	.start = __ipipe_max_prtrace_start,
+	.next  = __ipipe_prtrace_next,
+	.stop  = __ipipe_prtrace_stop,
+	.show  = __ipipe_prtrace_show
+};
+
+static int __ipipe_max_prtrace_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &__ipipe_max_ptrace_ops);
+}
+
+static ssize_t
+__ipipe_max_reset(struct file *file, const char __user *pbuffer,
+                  size_t count, loff_t *data)
+{
+	mutex_lock(&out_mutex);
+	ipipe_trace_max_reset();
+	mutex_unlock(&out_mutex);
+
+	return count;
+}
+
+struct file_operations __ipipe_max_prtrace_fops = {
+	.open       = __ipipe_max_prtrace_open,
+	.read       = seq_read,
+	.write      = __ipipe_max_reset,
+	.llseek     = seq_lseek,
+	.release    = seq_release,
+};
+
+static void *__ipipe_frozen_prtrace_start(struct seq_file *m, loff_t *pos)
+{
+	loff_t n = *pos;
+
+	mutex_lock(&out_mutex);
+
+	if (!n) {
+		struct ipipe_trace_path *tp;
+		int cpu;
+		unsigned long flags;
+
+		/* protect against max_path/frozen_path updates while we
+		 * haven't locked our target path, also avoid recursively
+		 * taking global_path_lock from NMI context */
+		flags = __ipipe_global_path_lock();
+
+		/* find the first of all per-cpu frozen paths */
+		print_path = NULL;
+		for_each_online_cpu(cpu) {
+			tp = &per_cpu(trace_path, cpu)[per_cpu(frozen_path, cpu)];
+			if (tp->end >= 0) {
+				print_path = tp;
+				break;
+			}
+		}
+		if (print_path)
+			print_path->dump_lock = 1;
+
+		__ipipe_global_path_unlock(flags);
+
+		if (!print_path)
+			return NULL;
+
+		/* back- and post-tracing length, post-trace length was frozen
+		   in __ipipe_trace, back-trace may have to be reduced due to
+		   buffer overrun */
+		print_pre_trace  = back_trace-1; /* substract freeze point */
+		print_post_trace = WRAP_POINT_NO(print_path->trace_pos -
+		                                 print_path->end - 1);
+		if (1+pre_trace+print_post_trace > IPIPE_TRACE_POINTS - 1)
+			print_pre_trace = IPIPE_TRACE_POINTS - 2 -
+				print_post_trace;
+
+		seq_printf(m, "I-pipe frozen back-tracing service on %s/ipipe-%s\n"
+			"------------------------------------------------------"
+			"------\n",
+			UTS_RELEASE, IPIPE_ARCH_STRING);
+		seq_printf(m, "CPU: %d, Freeze: %lld cycles, Trace Points: %d (+%d)\n",
+			cpu, print_path->point[print_path->begin].timestamp,
+			print_pre_trace+1, print_post_trace);
+		__ipipe_print_headline(m);
+	}
+
+	/* check if we are inside the trace range */
+	if (n >= print_pre_trace + 1 + print_post_trace)
+		return NULL;
+
+	/* return the next point to be shown */
+	return &print_path->point[WRAP_POINT_NO(print_path->begin-
+	                                        print_pre_trace+n)];
+}
+
+static struct seq_operations __ipipe_frozen_ptrace_ops = {
+	.start = __ipipe_frozen_prtrace_start,
+	.next  = __ipipe_prtrace_next,
+	.stop  = __ipipe_prtrace_stop,
+	.show  = __ipipe_prtrace_show
+};
+
+static int __ipipe_frozen_prtrace_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &__ipipe_frozen_ptrace_ops);
+}
+
+static ssize_t
+__ipipe_frozen_ctrl(struct file *file, const char __user *pbuffer,
+                    size_t count, loff_t *data)
+{
+	char *end, buf[16];
+	int val;
+	int n;
+
+	n = (count > sizeof(buf) - 1) ? sizeof(buf) - 1 : count;
+
+	if (copy_from_user(buf, pbuffer, n))
+		return -EFAULT;
+
+	buf[n] = '\0';
+	val = simple_strtol(buf, &end, 0);
+
+	if (((*end != '\0') && !isspace(*end)) || (val < 0))
+		return -EINVAL;
+
+	mutex_lock(&out_mutex);
+	ipipe_trace_frozen_reset();
+	if (val > 0)
+		ipipe_trace_freeze(-1);
+	mutex_unlock(&out_mutex);
+
+	return count;
+}
+
+struct file_operations __ipipe_frozen_prtrace_fops = {
+	.open       = __ipipe_frozen_prtrace_open,
+	.read       = seq_read,
+	.write      = __ipipe_frozen_ctrl,
+	.llseek     = seq_lseek,
+	.release    = seq_release,
+};
+
+static int __ipipe_rd_proc_val(char *page, char **start, off_t off,
+                               int count, int *eof, void *data)
+{
+	int len;
+
+	len = sprintf(page, "%u\n", *(int *)data);
+	len -= off;
+	if (len <= off + count)
+		*eof = 1;
+	*start = page + off;
+	if (len > count)
+		len = count;
+	if (len < 0)
+		len = 0;
+
+	return len;
+}
+
+static int __ipipe_wr_proc_val(struct file *file, const char __user *buffer,
+                               unsigned long count, void *data)
+{
+	char *end, buf[16];
+	int val;
+	int n;
+
+	n = (count > sizeof(buf) - 1) ? sizeof(buf) - 1 : count;
+
+	if (copy_from_user(buf, buffer, n))
+		return -EFAULT;
+
+	buf[n] = '\0';
+	val = simple_strtol(buf, &end, 0);
+
+	if (((*end != '\0') && !isspace(*end)) || (val < 0))
+		return -EINVAL;
+
+	mutex_lock(&out_mutex);
+	*(int *)data = val;
+	mutex_unlock(&out_mutex);
+
+	return count;
+}
+
+static int __ipipe_rd_trigger(char *page, char **start, off_t off, int count,
+			      int *eof, void *data)
+{
+	int len;
+
+	if (!trigger_begin)
+		return 0;
+
+	len = sprint_symbol(page, trigger_begin);
+	page[len++] = '\n';
+
+	len -= off;
+	if (len <= off + count)
+		*eof = 1;
+	*start = page + off;
+	if (len > count)
+		len = count;
+	if (len < 0)
+		len = 0;
+
+	return len;
+}
+
+static int __ipipe_wr_trigger(struct file *file, const char __user *buffer,
+			      unsigned long count, void *data)
+{
+	char buf[KSYM_SYMBOL_LEN];
+	unsigned long begin, end;
+
+	if (count > sizeof(buf) - 1)
+		count = sizeof(buf) - 1;
+	if (copy_from_user(buf, buffer, count))
+		return -EFAULT;
+	buf[count] = 0;
+	if (buf[count-1] == '\n')
+		buf[count-1] = 0;
+
+	begin = kallsyms_lookup_name(buf);
+	if (!begin || !kallsyms_lookup_size_offset(begin, &end, NULL))
+		return -ENOENT;
+	end += begin - 1;
+
+	mutex_lock(&out_mutex);
+	/* invalidate the current range before setting a new one */
+	trigger_end = 0;
+	wmb();
+	ipipe_trace_frozen_reset();
+
+	/* set new range */
+	trigger_begin = begin;
+	wmb();
+	trigger_end = end;
+	mutex_unlock(&out_mutex);
+
+	return count;
+}
+
+extern struct proc_dir_entry *ipipe_proc_root;
+
+static void __init
+__ipipe_create_trace_proc_val(struct proc_dir_entry *trace_dir,
+                              const char *name, int *value_ptr)
+{
+	struct proc_dir_entry *entry;
+
+	entry = create_proc_entry(name, 0644, trace_dir);
+	if (entry) {
+		entry->data = value_ptr;
+		entry->read_proc = __ipipe_rd_proc_val;
+		entry->write_proc = __ipipe_wr_proc_val;
+		entry->owner = THIS_MODULE;
+	}
+}
+
+void __init __ipipe_init_tracer(void)
+{
+	struct proc_dir_entry *trace_dir;
+	struct proc_dir_entry *entry;
+	unsigned long long start, end, min = ULLONG_MAX;
+	int i;
+#ifdef CONFIG_IPIPE_TRACE_VMALLOC
+	int cpu, path;
+
+	for_each_possible_cpu(cpu) {
+		struct ipipe_trace_path *tp_buf;
+
+		tp_buf = vmalloc_node(sizeof(struct ipipe_trace_path) *
+				      IPIPE_TRACE_PATHS, cpu_to_node(cpu));
+		if (!tp_buf) {
+			printk(KERN_ERR "I-pipe: "
+			       "insufficient memory for trace buffer.\n");
+			return;
+		}
+		memset(tp_buf, 0,
+		       sizeof(struct ipipe_trace_path) * IPIPE_TRACE_PATHS);
+		for (path = 0; path < IPIPE_TRACE_PATHS; path++) {
+			tp_buf[path].begin = -1;
+			tp_buf[path].end   = -1;
+		}
+		per_cpu(trace_path, cpu) = tp_buf;
+	}
+#endif /* CONFIG_IPIPE_TRACE_VMALLOC */
+	ipipe_trace_enable = CONFIG_IPIPE_TRACE_ENABLE_VALUE;
+
+	/* Calculate minimum overhead of __ipipe_trace() */
+	local_irq_disable_hw();
+	for (i = 0; i < 100; i++) {
+		ipipe_read_tsc(start);
+		__ipipe_trace(IPIPE_TRACE_FUNC, __BUILTIN_RETURN_ADDRESS0,
+			      __BUILTIN_RETURN_ADDRESS1, 0);
+		ipipe_read_tsc(end);
+
+		end -= start;
+		if (end < min)
+			min = end;
+	}
+	local_irq_enable_hw();
+	trace_overhead = ipipe_tsc2ns(min);
+
+	trace_dir = create_proc_entry("trace", S_IFDIR, ipipe_proc_root);
+
+	entry = create_proc_entry("max", 0644, trace_dir);
+	if (entry)
+		entry->proc_fops = &__ipipe_max_prtrace_fops;
+
+	entry = create_proc_entry("frozen", 0644, trace_dir);
+	if (entry)
+		entry->proc_fops = &__ipipe_frozen_prtrace_fops;
+
+	entry = create_proc_entry("trigger", 0644, trace_dir);
+	if (entry) {
+		entry->read_proc = __ipipe_rd_trigger;
+		entry->write_proc = __ipipe_wr_trigger;
+		entry->owner = THIS_MODULE;
+	}
+
+	__ipipe_create_trace_proc_val(trace_dir, "pre_trace_points",
+	                              &pre_trace);
+	__ipipe_create_trace_proc_val(trace_dir, "post_trace_points",
+	                              &post_trace);
+	__ipipe_create_trace_proc_val(trace_dir, "back_trace_points",
+	                              &back_trace);
+	__ipipe_create_trace_proc_val(trace_dir, "verbose",
+	                              &verbose_trace);
+	__ipipe_create_trace_proc_val(trace_dir, "enable",
+	                              &ipipe_trace_enable);
+}
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/irq/chip.c b/kernel/irq/chip.c
index 10b5092..1033b95 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -351,7 +351,9 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc)
 	irqreturn_t action_ret;
 
 	spin_lock(&desc->lock);
+#ifndef CONFIG_IPIPE
 	mask_ack_irq(desc, irq);
+#endif /* CONFIG_IPIPE */
 
 	if (unlikely(desc->status & IRQ_INPROGRESS))
 		goto out_unlock;
@@ -427,8 +429,13 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 
 	spin_lock(&desc->lock);
 	desc->status &= ~IRQ_INPROGRESS;
+#ifdef CONFIG_IPIPE
+	desc->chip->unmask(irq);
+out:
+#else
 out:
 	desc->chip->eoi(irq);
+#endif
 
 	spin_unlock(&desc->lock);
 }
@@ -469,8 +476,10 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 	}
 	kstat_incr_irqs_this_cpu(irq, desc);
 
+#ifndef CONFIG_IPIPE
 	/* Start handling the irq */
 	desc->chip->ack(irq);
+#endif /* CONFIG_IPIPE */
 
 	/* Mark the IRQ currently in progress.*/
 	desc->status |= IRQ_INPROGRESS;
@@ -510,6 +519,85 @@ out_unlock:
 	spin_unlock(&desc->lock);
 }
 
+#ifdef CONFIG_IPIPE
+
+void __ipipe_ack_simple_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void __ipipe_end_simple_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void __ipipe_ack_level_irq(unsigned irq, struct irq_desc *desc)
+{
+	mask_ack_irq(desc, irq);
+}
+
+void __ipipe_end_level_irq(unsigned irq, struct irq_desc *desc)
+{
+	if (desc->chip->unmask)
+		desc->chip->unmask(irq);
+}
+
+void __ipipe_ack_fasteoi_irq(unsigned irq, struct irq_desc *desc)
+{
+	desc->chip->eoi(irq);
+}
+
+void __ipipe_end_fasteoi_irq(unsigned irq, struct irq_desc *desc)
+{
+	/*
+	 * Non-requestable IRQs should not be masked in EOI handler.
+	 */
+	if (!(desc->status & IRQ_NOREQUEST))
+		desc->chip->unmask(irq);
+}
+
+void __ipipe_ack_edge_irq(unsigned irq, struct irq_desc *desc)
+{
+	desc->chip->ack(irq);
+}
+
+void __ipipe_ack_percpu_irq(unsigned irq, struct irq_desc *desc)
+{
+	if (desc->chip->ack)
+		desc->chip->ack(irq);
+}
+
+void __ipipe_end_percpu_irq(unsigned irq, struct irq_desc *desc)
+{
+	if (desc->chip->eoi)
+		desc->chip->eoi(irq);
+}
+
+void __ipipe_end_edge_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void __ipipe_ack_bad_irq(unsigned irq, struct irq_desc *desc)
+{
+	static int done;
+
+	handle_bad_irq(irq, desc);
+
+	if (!done) {
+		printk(KERN_WARNING "%s: unknown flow handler for IRQ %d\n",
+		       __FUNCTION__, irq);
+		done = 1;
+	}
+}
+
+void __ipipe_noack_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void __ipipe_noend_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+#endif /* CONFIG_IPIPE */
+
 /**
  *	handle_percpu_IRQ - Per CPU local irq handler
  *	@irq:	the interrupt number
@@ -524,8 +612,10 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 
 	kstat_incr_irqs_this_cpu(irq, desc);
 
+#ifndef CONFIG_IPIPE
 	if (desc->chip->ack)
 		desc->chip->ack(irq);
+#endif /* CONFIG_IPIPE */
 
 	action_ret = handle_IRQ_event(irq, desc->action);
 	if (!noirqdebug)
@@ -536,20 +626,37 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 }
 
 void
-__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
-		  const char *name)
+___set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
+		   const char *name)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
-	unsigned long flags;
-
-	if (!desc) {
-		printk(KERN_ERR
-		       "Trying to install type control for IRQ%d\n", irq);
-		return;
-	}
 
 	if (!handle)
 		handle = handle_bad_irq;
+#ifdef CONFIG_IPIPE
+	else if (handle == &handle_simple_irq) {
+		desc->ipipe_ack = &__ipipe_ack_simple_irq;
+		desc->ipipe_end = &__ipipe_end_simple_irq;
+	}
+	else if (handle == &handle_level_irq) {
+		desc->ipipe_ack = &__ipipe_ack_level_irq;
+		desc->ipipe_end = &__ipipe_end_level_irq;
+	}
+	else if (handle == &handle_edge_irq) {
+		desc->ipipe_ack = &__ipipe_ack_edge_irq;
+		desc->ipipe_end = &__ipipe_end_edge_irq;
+	}
+	else if (handle == &handle_fasteoi_irq) {
+		desc->ipipe_ack = &__ipipe_ack_fasteoi_irq;
+		desc->ipipe_end = &__ipipe_end_fasteoi_irq;
+	}
+#ifdef CONFIG_SMP
+	else if (handle == &handle_percpu_irq) {
+		desc->ipipe_ack = &__ipipe_ack_percpu_irq;
+		desc->ipipe_end = &__ipipe_end_percpu_irq;
+	}
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_IPIPE */
 	else if (desc->chip == &no_irq_chip) {
 		printk(KERN_WARNING "Trying to install %sinterrupt handler "
 		       "for IRQ%d\n", is_chained ? "chained " : "", irq);
@@ -561,9 +668,21 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 		 * dummy_irq_chip for easy transition.
 		 */
 		desc->chip = &dummy_irq_chip;
+#ifdef CONFIG_IPIPE
+		desc->ipipe_ack = &__ipipe_noack_irq;
+		desc->ipipe_end = &__ipipe_noend_irq;
+#endif /* CONFIG_IPIPE */
 	}
-
-	spin_lock_irqsave(&desc->lock, flags);
+#ifdef CONFIG_IPIPE
+ 	else if (is_chained) {
+ 		desc->ipipe_ack = handle;
+ 		desc->ipipe_end = &__ipipe_noend_irq;
+		handle = &__ipipe_noack_irq;
+ 	} else {
+ 		desc->ipipe_ack = &__ipipe_ack_bad_irq;
+ 		desc->ipipe_end = &__ipipe_noend_irq;
+	}
+#endif /* CONFIG_IPIPE */
 
 	/* Uninstall? */
 	if (handle == handle_bad_irq) {
@@ -571,9 +690,17 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 			mask_ack_irq(desc, irq);
 		desc->status |= IRQ_DISABLED;
 		desc->depth = 1;
+#ifdef CONFIG_IPIPE
+		desc->ipipe_ack = &__ipipe_ack_bad_irq;
+		desc->ipipe_end = &__ipipe_noend_irq;
+#endif /* CONFIG_IPIPE */
 	}
 	desc->handle_irq = handle;
 	desc->name = name;
+#ifdef CONFIG_IPIPE
+	/* Suppress intermediate trampoline routine. */
+	ipipe_root_domain->irqs[irq].acknowledge = desc->ipipe_ack;
+#endif /* CONFIG_IPIPE */
 
 	if (handle != handle_bad_irq && is_chained) {
 		desc->status &= ~IRQ_DISABLED;
@@ -581,6 +708,23 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 		desc->depth = 0;
 		desc->chip->startup(irq);
 	}
+}
+
+void
+__set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
+		  const char *name)
+{
+	struct irq_desc *desc = irq_to_desc(irq);
+	unsigned long flags;
+
+	if (!desc) {
+		printk(KERN_ERR
+		       "Trying to install type control for IRQ%d\n", irq);
+		return;
+	}
+
+	spin_lock_irqsave(&desc->lock, flags);
+	___set_irq_handler(irq, handle, is_chained, name);
 	spin_unlock_irqrestore(&desc->lock, flags);
 }
 
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/irq/handle.c b/kernel/irq/handle.c
index c815b42..f2efd4e 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -179,8 +179,10 @@ unsigned int __do_IRQ(unsigned int irq)
 		/*
 		 * No locking required for CPU-local interrupts:
 		 */
+#ifndef CONFIG_IPIPE
 		if (desc->chip->ack)
 			desc->chip->ack(irq);
+#endif
 		if (likely(!(desc->status & IRQ_DISABLED))) {
 			action_ret = handle_IRQ_event(irq, desc->action);
 			if (!noirqdebug)
@@ -191,8 +193,10 @@ unsigned int __do_IRQ(unsigned int irq)
 	}
 
 	spin_lock(&desc->lock);
+#ifndef CONFIG_IPIPE
 	if (desc->chip->ack)
 		desc->chip->ack(irq);
+#endif
 	/*
 	 * REPLAY is when Linux resends an IRQ that was dropped earlier
 	 * WAITING is used by probe to mark irqs that are being tested
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/lockdep.c b/kernel/lockdep.c
index 46a4041..bc57809 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2188,7 +2188,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
 	/* we'll do an OFF -> ON transition: */
 	curr->hardirqs_enabled = 1;
 
-	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled() && !irqs_disabled_hw()))
 		return;
 	if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
 		return;
@@ -2231,7 +2231,7 @@ void trace_hardirqs_off_caller(unsigned long ip)
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
 
-	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled() && !irqs_disabled_hw()))
 		return;
 
 	if (curr->hardirqs_enabled) {
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/panic.c b/kernel/panic.c
index 4d50883..1afea02 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/panic.c
+++ b/kernel/panic.c
@@ -21,6 +21,7 @@
 #include <linux/debug_locks.h>
 #include <linux/random.h>
 #include <linux/kallsyms.h>
+#include <linux/ipipe_trace.h>
 
 int panic_on_oops;
 static unsigned long tainted_mask;
@@ -285,6 +286,8 @@ int oops_may_print(void)
  */
 void oops_enter(void)
 {
+	ipipe_trace_panic_freeze();
+	ipipe_disable_context_check(ipipe_processor_id());
 	debug_locks_off(); /* can't trust the integrity of the kernel anymore */
 	do_oops_enter_exit();
 }
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/power/disk.c b/kernel/power/disk.c
index c9d7408..e6915f2 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -208,6 +208,7 @@ static int create_image(int platform_mode)
 
 	device_pm_lock();
 	local_irq_disable();
+ 	local_irq_disable_hw_cond();
 	/* At this point, device_suspend() has been called, but *not*
 	 * device_power_down(). We *must* call device_power_down() now.
 	 * Otherwise, drivers for some devices (e.g. interrupt controllers)
@@ -241,6 +242,7 @@ static int create_image(int platform_mode)
 	device_power_up(in_suspend ?
 		(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
  Enable_irqs:
+ 	local_irq_enable_hw_cond();
 	local_irq_enable();
 	device_pm_unlock();
 	return error;
@@ -324,6 +326,7 @@ static int resume_target_kernel(void)
 
 	device_pm_lock();
 	local_irq_disable();
+ 	local_irq_disable_hw_cond();
 	error = device_power_down(PMSG_QUIESCE);
 	if (error) {
 		printk(KERN_ERR "PM: Some devices failed to power down, "
@@ -354,6 +357,7 @@ static int resume_target_kernel(void)
 	touch_softlockup_watchdog();
 	device_power_up(PMSG_RECOVER);
  Enable_irqs:
+	local_irq_enable_hw_cond();
 	local_irq_enable();
 	device_pm_unlock();
 	return error;
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/printk.c b/kernel/printk.c
index b84eec7..eab2d52 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/printk.c
+++ b/kernel/printk.c
@@ -533,6 +533,41 @@ static int have_callable_console(void)
 	return 0;
 }
 
+#ifdef CONFIG_IPIPE
+
+static ipipe_spinlock_t __ipipe_printk_lock = IPIPE_SPIN_LOCK_UNLOCKED;
+
+static int __ipipe_printk_fill;
+
+static char __ipipe_printk_buf[__LOG_BUF_LEN];
+
+void __ipipe_flush_printk (unsigned virq, void *cookie)
+{
+	char *p = __ipipe_printk_buf;
+	int len, lmax, out = 0;
+	unsigned long flags;
+
+	goto start;
+
+	do {
+		spin_unlock_irqrestore(&__ipipe_printk_lock, flags);
+ start:
+		lmax = __ipipe_printk_fill;
+		while (out < lmax) {
+			len = strlen(p) + 1;
+			printk("%s",p);
+			p += len;
+			out += len;
+		}
+		spin_lock_irqsave(&__ipipe_printk_lock, flags);
+	}
+	while (__ipipe_printk_fill != lmax);
+
+	__ipipe_printk_fill = 0;
+
+	spin_unlock_irqrestore(&__ipipe_printk_lock, flags);
+}
+
 /**
  * printk - print a kernel message
  * @fmt: format string
@@ -557,6 +592,63 @@ static int have_callable_console(void)
 
 asmlinkage int printk(const char *fmt, ...)
 {
+	int r, fbytes, oldcount;
+	int sprintk = 1;
+	int cs = -1;
+	unsigned long flags;
+	va_list args;
+
+	va_start(args, fmt);
+
+	if (test_bit(IPIPE_SPRINTK_FLAG, &ipipe_current_domain->flags) ||
+	    oops_in_progress)
+		cs = ipipe_disable_context_check(ipipe_processor_id());
+	else if (ipipe_current_domain == ipipe_root_domain) {
+		struct ipipe_domain *dom;
+
+		local_irq_save_hw(flags);
+		list_for_each_entry(dom, &__ipipe_pipeline, p_link) {
+			if (dom == ipipe_root_domain)
+				break;
+			if (test_bit(IPIPE_STALL_FLAG,
+				     &ipipe_cpudom_var(dom, status)))
+				sprintk = 0;
+		}
+		local_irq_restore_hw(flags);
+	} else
+		sprintk = 0;
+
+	if (sprintk) {
+		r = vprintk(fmt, args);
+		if (cs != -1)
+			ipipe_restore_context_check(ipipe_processor_id(), cs);
+		goto out;
+	}
+
+	spin_lock_irqsave(&__ipipe_printk_lock, flags);
+
+	oldcount = __ipipe_printk_fill;
+	fbytes = __LOG_BUF_LEN - oldcount;
+
+	if (fbytes > 1)	{
+		r = vscnprintf(__ipipe_printk_buf + __ipipe_printk_fill,
+			       fbytes, fmt, args) + 1; /* account for the null byte */
+		__ipipe_printk_fill += r;
+	} else
+		r = 0;
+
+	spin_unlock_irqrestore(&__ipipe_printk_lock, flags);
+
+	if (oldcount == 0)
+		ipipe_trigger_irq(__ipipe_printk_virq);
+out:
+	va_end(args);
+
+	return r;
+}
+#else /* !CONFIG_IPIPE */
+asmlinkage int printk(const char *fmt, ...)
+{
 	va_list args;
 	int r;
 
@@ -566,6 +658,7 @@ asmlinkage int printk(const char *fmt, ...)
 
 	return r;
 }
+#endif /* CONFIG_IPIPE */
 
 /* cpu currently holding logbuf_lock */
 static volatile unsigned int printk_cpu = UINT_MAX;
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/sched.c b/kernel/sched.c
index 4437088..13b22bb 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/sched.c
+++ b/kernel/sched.c
@@ -2255,7 +2255,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 	smp_wmb();
 	rq = task_rq_lock(p, &flags);
 	old_state = p->state;
-	if (!(old_state & state))
+	if (!(old_state & state) || (old_state & (TASK_NOWAKEUP|TASK_ATOMICSWITCH)))
 		goto out;
 
 	if (p->se.on_rq)
@@ -2609,13 +2609,15 @@ asmlinkage void schedule_tail(struct task_struct *prev)
 #endif
 	if (current->set_child_tid)
 		put_user(task_pid_vnr(current), current->set_child_tid);
+
+ 	ipipe_init_notify(current);
 }
 
 /*
  * context_switch - switch to the new MM and the new
  * thread's register state.
  */
-static inline void
+static inline int
 context_switch(struct rq *rq, struct task_struct *prev,
 	       struct task_struct *next)
 {
@@ -2657,12 +2659,23 @@ context_switch(struct rq *rq, struct task_struct *prev,
 	switch_to(prev, next, prev);
 
 	barrier();
+
+#ifdef CONFIG_IPIPE_DELAYED_ATOMICSW
+	current->state &= ~TASK_ATOMICSWITCH;
+#else
+	prev->state &= ~TASK_ATOMICSWITCH;
+#endif
+	if (task_hijacked(prev))
+		return 1;
+
 	/*
 	 * this_rq must be evaluated again because prev may have moved
 	 * CPUs since it called schedule(), thus the 'rq' on its stack
 	 * frame will be invalid.
 	 */
 	finish_task_switch(this_rq(), prev);
+
+	return 0;
 }
 
 /*
@@ -4335,6 +4348,7 @@ EXPORT_SYMBOL(add_preempt_count);
 
 void __kprobes sub_preempt_count(int val)
 {
+ 	ipipe_check_context(ipipe_root_domain);
 #ifdef CONFIG_DEBUG_PREEMPT
 	/*
 	 * Underflow?
@@ -4383,6 +4397,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
  */
 static inline void schedule_debug(struct task_struct *prev)
 {
+	ipipe_check_context(ipipe_root_domain);
 	/*
 	 * Test if we are atomic. Since do_exit() needs to call into
 	 * schedule() atomically, we ignore that path for now.
@@ -4456,6 +4471,9 @@ need_resched:
 	rcu_qsctr_inc(cpu);
 	prev = rq->curr;
 	switch_count = &prev->nivcsw;
+ 	if (unlikely(prev->state & TASK_ATOMICSWITCH))
+		/* Pop one disable level -- one still remains. */
+		preempt_enable();
 
 	release_kernel_lock(prev);
 need_resched_nonpreemptible:
@@ -4495,15 +4513,18 @@ need_resched_nonpreemptible:
 		rq->curr = next;
 		++*switch_count;
 
-		context_switch(rq, prev, next); /* unlocks the rq */
+		if (context_switch(rq, prev, next)) /* unlocks the rq unless hijacked */
+			return;
 		/*
 		 * the context switch might have flipped the stack from under
 		 * us, hence refresh the local variables.
 		 */
 		cpu = smp_processor_id();
 		rq = cpu_rq(cpu);
-	} else
+	} else {
+		prev->state &= ~TASK_ATOMICSWITCH;
 		spin_unlock_irq(&rq->lock);
+	}
 
 	if (unlikely(reacquire_kernel_lock(current) < 0))
 		goto need_resched_nonpreemptible;
@@ -5246,6 +5267,7 @@ recheck:
 
 	oldprio = p->prio;
 	__setscheduler(rq, p, policy, param->sched_priority);
+  	ipipe_setsched_notify(p);
 
 	if (running)
 		p->sched_class->set_curr_task(rq);
@@ -5575,6 +5597,7 @@ static void __cond_resched(void)
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
 	__might_sleep(__FILE__, __LINE__);
 #endif
+	ipipe_check_context(ipipe_root_domain);
 	/*
 	 * The BKS might be reacquired before we have dropped
 	 * PREEMPT_ACTIVE, which could trigger a second
@@ -9393,3 +9416,60 @@ struct cgroup_subsys cpuacct_subsys = {
 	.subsys_id = cpuacct_subsys_id,
 };
 #endif	/* CONFIG_CGROUP_CPUACCT */
+
+#ifdef CONFIG_IPIPE
+
+int ipipe_setscheduler_root (struct task_struct *p, int policy, int prio)
+{
+	const struct sched_class *prev_class = p->sched_class;
+	int oldprio, on_rq, running;
+	unsigned long flags;
+	struct rq *rq;
+
+	spin_lock_irqsave(&p->pi_lock, flags);
+	rq = __task_rq_lock(p);
+	update_rq_clock(rq);
+	on_rq = p->se.on_rq;
+	running = task_running(rq, p);
+
+	if (on_rq)
+		deactivate_task(rq, p, 0);
+	if (running)
+		p->sched_class->put_prev_task(rq, p);
+
+	oldprio = p->prio;
+	__setscheduler(rq, p, policy, prio);
+	ipipe_setsched_notify(p);
+
+	if (running)
+		p->sched_class->set_curr_task(rq);
+	if (on_rq) {
+		activate_task(rq, p, 0);
+		check_class_changed(rq, p, prev_class, oldprio, running);
+	}
+	__task_rq_unlock(rq);
+	spin_unlock_irqrestore(&p->pi_lock, flags);
+
+	rt_mutex_adjust_pi(p);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(ipipe_setscheduler_root);
+
+int ipipe_reenter_root (struct task_struct *prev, int policy, int prio)
+{
+	finish_task_switch(this_rq(), prev);
+
+	(void)reacquire_kernel_lock(current);
+	preempt_enable_no_resched();
+
+	if (current->policy != policy || current->rt_priority != prio)
+		return ipipe_setscheduler_root(current, policy, prio);
+
+	return 0;
+}
+
+EXPORT_SYMBOL(ipipe_reenter_root);
+
+#endif /* CONFIG_IPIPE */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/signal.c b/kernel/signal.c
index 28859a9..734c5c0 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/signal.c
+++ b/kernel/signal.c
@@ -494,6 +494,7 @@ void signal_wake_up(struct task_struct *t, int resume)
 	unsigned int mask;
 
 	set_tsk_thread_flag(t, TIF_SIGPENDING);
+	ipipe_sigwake_notify(t); /* TIF_SIGPENDING must be set first. */
 
 	/*
 	 * For SIGKILL, we want to wake it up in the stopped/traced/killable
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/spinlock.c b/kernel/spinlock.c
index 29ab207..c21e314 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -87,7 +87,7 @@ unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
 	 * _raw_spin_lock_flags() code, because lockdep assumes
 	 * that interrupts are not re-enabled during lock-acquire:
 	 */
-#ifdef CONFIG_LOCKDEP
+#if defined(CONFIG_LOCKDEP) || defined(CONFIG_IPIPE)
 	LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
 #else
 	_raw_spin_lock_flags(lock, &flags);
@@ -304,7 +304,7 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclas
 	 * _raw_spin_lock_flags() code, because lockdep assumes
 	 * that interrupts are not re-enabled during lock-acquire:
 	 */
-#ifdef CONFIG_LOCKDEP
+#if defined(CONFIG_LOCKDEP) || defined(CONFIG_IPIPE)
 	LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
 #else
 	_raw_spin_lock_flags(lock, &flags);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/time/tick-common.c b/kernel/time/tick-common.c
index df12434..3d63445 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -69,7 +69,7 @@ static void tick_periodic(int cpu)
 		write_sequnlock(&xtime_lock);
 	}
 
-	update_process_times(user_mode(get_irq_regs()));
+	update_root_process_times(get_irq_regs());
 	profile_tick(CPU_PROFILING);
 }
 
@@ -167,6 +167,10 @@ static void tick_setup_device(struct tick_device *td,
 
 	td->evtdev = newdev;
 
+	/* I-pipe: derive global tick IRQ from CPU 0 */
+	if (cpu == 0)
+		ipipe_update_tick_evtdev(newdev);
+
 	/*
 	 * When the device is not per cpu, pin the interrupt to the
 	 * current cpu:
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 342fc9c..3665e47 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -507,7 +507,7 @@ static void tick_nohz_handler(struct clock_event_device *dev)
 		ts->idle_jiffies++;
 	}
 
-	update_process_times(user_mode(regs));
+	update_root_process_times(regs);
 	profile_tick(CPU_PROFILING);
 
 	while (tick_nohz_reprogram(ts, now)) {
@@ -658,7 +658,7 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
 			touch_softlockup_watchdog();
 			ts->idle_jiffies++;
 		}
-		update_process_times(user_mode(regs));
+		update_root_process_times(regs);
 		profile_tick(CPU_PROFILING);
 	}
 
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/timer.c b/kernel/timer.c
index a5eaea2..6ecc85e 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/timer.c
+++ b/kernel/timer.c
@@ -1052,6 +1052,26 @@ void update_process_times(int user_tick)
 	run_posix_cpu_timers(p);
 }
 
+#ifdef CONFIG_IPIPE
+
+void update_root_process_times(struct pt_regs *regs)
+{
+	int cpu, user_tick = user_mode(regs);
+
+	if (__ipipe_root_tick_p(regs)) {
+		update_process_times(user_tick);
+		return;
+	}
+
+	run_local_timers();
+	cpu = smp_processor_id();
+	if (rcu_pending(cpu))
+		rcu_check_callbacks(cpu, user_tick);
+	run_posix_cpu_timers(current);
+}
+
+#endif
+
 /*
  * Nr of active tasks - counted in fixed-point numbers
  */
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 33dbefd..fd9736e 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -33,7 +33,7 @@ menu "Tracers"
 
 config FUNCTION_TRACER
 	bool "Kernel Function Tracer"
-	depends on HAVE_FUNCTION_TRACER
+	depends on HAVE_FUNCTION_TRACER && !IPIPE_TRACE
 	depends on DEBUG_KERNEL
 	select FRAME_POINTER
 	select TRACING
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/Kconfig.debug b/lib/Kconfig.debug
index b0f239e..fdc111b 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -128,6 +128,8 @@ config DEBUG_SECTION_MISMATCH
 	  - Enable verbose reporting from modpost to help solving
 	    the section mismatches reported.
 
+source "kernel/ipipe/Kconfig.debug"
+
 config DEBUG_KERNEL
 	bool "Kernel debugging"
 	help
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/bust_spinlocks.c b/lib/bust_spinlocks.c
index 486da62..9a0f064 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/bust_spinlocks.c
+++ b/lib/bust_spinlocks.c
@@ -12,6 +12,7 @@
 #include <linux/tty.h>
 #include <linux/wait.h>
 #include <linux/vt_kern.h>
+#include <linux/ipipe_trace.h>
 
 
 void __attribute__((weak)) bust_spinlocks(int yes)
@@ -22,6 +23,7 @@ void __attribute__((weak)) bust_spinlocks(int yes)
 #ifdef CONFIG_VT
 		unblank_screen();
 #endif
+ 		ipipe_trace_panic_dump();
 		if (--oops_in_progress == 0)
 			wake_up_klogd();
 	}
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/ioremap.c b/lib/ioremap.c
index 14c6078..a275469 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -85,8 +85,8 @@ int ioremap_page_range(unsigned long addr,
 		if (err)
 			break;
 	} while (pgd++, addr = next, addr != end);
-
-	flush_cache_vmap(start, end);
+	__ipipe_pin_range_globally(start, end);
+ 	flush_cache_vmap(start, end);
 
 	return err;
 }
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 0f8fc22..90dc46f 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -12,10 +12,13 @@ notrace unsigned int debug_smp_processor_id(void)
 	unsigned long preempt_count = preempt_count();
 	int this_cpu = raw_smp_processor_id();
 
+	if (!ipipe_root_domain_p)
+		goto out;
+
 	if (likely(preempt_count))
 		goto out;
 
-	if (irqs_disabled())
+	if (irqs_disabled() || irqs_disabled_hw())
 		goto out;
 
 	/*
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 9c4b025..08f096b 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/lib/spinlock_debug.c
+++ b/lib/spinlock_debug.c
@@ -133,6 +133,8 @@ void _raw_spin_lock(spinlock_t *lock)
 	debug_spin_lock_after(lock);
 }
 
+EXPORT_SYMBOL(_raw_spin_lock);
+
 int _raw_spin_trylock(spinlock_t *lock)
 {
 	int ret = __raw_spin_trylock(&lock->raw_lock);
@@ -148,12 +150,16 @@ int _raw_spin_trylock(spinlock_t *lock)
 	return ret;
 }
 
+EXPORT_SYMBOL(_raw_spin_trylock);
+
 void _raw_spin_unlock(spinlock_t *lock)
 {
 	debug_spin_unlock(lock);
 	__raw_spin_unlock(&lock->raw_lock);
 }
 
+EXPORT_SYMBOL(_raw_spin_unlock);
+
 static void rwlock_bug(rwlock_t *lock, const char *msg)
 {
 	if (!debug_locks_off())
@@ -199,6 +205,8 @@ void _raw_read_lock(rwlock_t *lock)
 	__raw_read_lock(&lock->raw_lock);
 }
 
+EXPORT_SYMBOL(_raw_read_lock);
+
 int _raw_read_trylock(rwlock_t *lock)
 {
 	int ret = __raw_read_trylock(&lock->raw_lock);
@@ -212,12 +220,16 @@ int _raw_read_trylock(rwlock_t *lock)
 	return ret;
 }
 
+EXPORT_SYMBOL(_raw_read_trylock);
+
 void _raw_read_unlock(rwlock_t *lock)
 {
 	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
 	__raw_read_unlock(&lock->raw_lock);
 }
 
+EXPORT_SYMBOL(_raw_read_unlock);
+
 static inline void debug_write_lock_before(rwlock_t *lock)
 {
 	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
@@ -275,6 +287,8 @@ void _raw_write_lock(rwlock_t *lock)
 	debug_write_lock_after(lock);
 }
 
+EXPORT_SYMBOL(_raw_write_lock);
+
 int _raw_write_trylock(rwlock_t *lock)
 {
 	int ret = __raw_write_trylock(&lock->raw_lock);
@@ -290,8 +304,12 @@ int _raw_write_trylock(rwlock_t *lock)
 	return ret;
 }
 
+EXPORT_SYMBOL(_raw_write_trylock);
+
 void _raw_write_unlock(rwlock_t *lock)
 {
 	debug_write_unlock(lock);
 	__raw_write_unlock(&lock->raw_lock);
 }
+
+EXPORT_SYMBOL(_raw_write_unlock);
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/mm/memory.c b/mm/memory.c
index 164951c..b3b1d8f 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/mm/memory.c
+++ b/mm/memory.c
@@ -52,6 +52,7 @@
 #include <linux/writeback.h>
 #include <linux/memcontrol.h>
 #include <linux/mmu_notifier.h>
+#include <linux/vmalloc.h>
 
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -482,6 +483,32 @@ out:
 	return pfn_to_page(pfn);
 }
 
+static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
+{
+	/*
+	 * If the source page was a PFN mapping, we don't have
+	 * a "struct page" for it. We do a best-effort copy by
+	 * just copying from the original user address. If that
+	 * fails, we just zero-fill it. Live with it.
+	 */
+	if (unlikely(!src)) {
+		void *kaddr = kmap_atomic(dst, KM_USER0);
+		void __user *uaddr = (void __user *)(va & PAGE_MASK);
+
+		/*
+		 * This really shouldn't fail, because the page is there
+		 * in the page tables. But it might just be unreadable,
+		 * in which case we just give up and fill the result with
+		 * zeroes.
+		 */
+		if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
+			memset(kaddr, 0, PAGE_SIZE);
+		kunmap_atomic(kaddr, KM_USER0);
+		flush_dcache_page(dst);
+	} else
+		copy_user_highpage(dst, src, va, vma);
+}
+
 /*
  * copy one vm_area from one task to the other. Assumes the page tables
  * already present in the new task to be cleared in the whole range
@@ -490,8 +517,8 @@ out:
 
 static inline void
 copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
-		pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
-		unsigned long addr, int *rss)
+	     pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
+	     unsigned long addr, int *rss, struct page *uncow_page)
 {
 	unsigned long vm_flags = vma->vm_flags;
 	pte_t pte = *src_pte;
@@ -530,6 +557,21 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	 * in the parent and the child
 	 */
 	if (is_cow_mapping(vm_flags)) {
+#ifdef CONFIG_IPIPE
+		if (uncow_page) {
+			struct page *old_page = vm_normal_page(vma, addr, pte);
+			cow_user_page(uncow_page, old_page, addr, vma);
+			pte = mk_pte(uncow_page, vma->vm_page_prot);
+
+			if (vm_flags & VM_SHARED)
+				pte = pte_mkclean(pte);
+			pte = pte_mkold(pte);
+
+			page_add_new_anon_rmap(uncow_page, vma, addr);
+			rss[!!PageAnon(uncow_page)]++;
+			goto out_set_pte;
+		}
+#endif /* CONFIG_IPIPE */
 		ptep_set_wrprotect(src_mm, addr, src_pte);
 		pte = pte_wrprotect(pte);
 	}
@@ -560,13 +602,27 @@ static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	pte_t *src_pte, *dst_pte;
 	spinlock_t *src_ptl, *dst_ptl;
 	int progress = 0;
+	struct page *uncow_page = NULL;
 	int rss[2];
-
+#ifdef CONFIG_IPIPE
+	int do_cow_break = 0;
+again:
+	if (do_cow_break) {
+		uncow_page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
+		if (!uncow_page)
+			return -ENOMEM;
+		do_cow_break = 0;
+	}
+#else
 again:
+#endif
 	rss[1] = rss[0] = 0;
 	dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl);
-	if (!dst_pte)
+	if (!dst_pte) {
+		if (uncow_page)
+			page_cache_release(uncow_page);
 		return -ENOMEM;
+	}
 	src_pte = pte_offset_map_nested(src_pmd, addr);
 	src_ptl = pte_lockptr(src_mm, src_pmd);
 	spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
@@ -587,7 +643,26 @@ again:
 			progress++;
 			continue;
 		}
-		copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss);
+#ifdef CONFIG_IPIPE
+		if (likely(uncow_page == NULL) && likely(pte_present(*src_pte))) {
+			if (is_cow_mapping(vma->vm_flags)) {
+				if (((vma->vm_flags|src_mm->def_flags) & (VM_LOCKED|VM_PINNED))
+				    == (VM_LOCKED|VM_PINNED)) {
+				    	arch_leave_lazy_mmu_mode();
+				    	spin_unlock(src_ptl);
+				    	pte_unmap_nested(src_pte);
+				    	add_mm_rss(dst_mm, rss[0], rss[1]);
+				    	pte_unmap_unlock(dst_pte, dst_ptl);
+				    	cond_resched();
+					do_cow_break = 1;
+					goto again;
+				}
+			}
+		}
+#endif
+		copy_one_pte(dst_mm, src_mm, dst_pte,
+			     src_pte, vma, addr, rss, uncow_page);
+		uncow_page = NULL;
 		progress += 8;
 	} while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
 
@@ -1734,32 +1809,6 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 	return pte;
 }
 
-static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
-{
-	/*
-	 * If the source page was a PFN mapping, we don't have
-	 * a "struct page" for it. We do a best-effort copy by
-	 * just copying from the original user address. If that
-	 * fails, we just zero-fill it. Live with it.
-	 */
-	if (unlikely(!src)) {
-		void *kaddr = kmap_atomic(dst, KM_USER0);
-		void __user *uaddr = (void __user *)(va & PAGE_MASK);
-
-		/*
-		 * This really shouldn't fail, because the page is there
-		 * in the page tables. But it might just be unreadable,
-		 * in which case we just give up and fill the result with
-		 * zeroes.
-		 */
-		if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
-			memset(kaddr, 0, PAGE_SIZE);
-		kunmap_atomic(kaddr, KM_USER0);
-		flush_dcache_page(dst);
-	} else
-		copy_user_highpage(dst, src, va, vma);
-}
-
 /*
  * This routine handles present pages, when users try to write
  * to a shared page. It is done by copying the page to a new address
@@ -3049,3 +3098,111 @@ void print_vma_addr(char *prefix, unsigned long ip)
 	}
 	up_read(&current->mm->mmap_sem);
 }
+
+#ifdef CONFIG_IPIPE
+
+static inline int ipipe_pin_pte_range(struct mm_struct *mm, pmd_t *pmd,
+				      struct vm_area_struct *vma,
+				      unsigned long addr, unsigned long end)
+{
+	spinlock_t *ptl;
+	pte_t *pte;
+
+	do {
+		pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
+		if (!pte)
+			continue;
+
+		if (!pte_present(*pte) || pte_write(*pte)) {
+			pte_unmap_unlock(pte, ptl);
+			continue;
+		}
+
+		if (do_wp_page(mm, vma, addr, pte, pmd, ptl, *pte) == VM_FAULT_OOM)
+			return -ENOMEM;
+	} while (addr += PAGE_SIZE, addr != end);
+	return 0;
+}
+
+static inline int ipipe_pin_pmd_range(struct mm_struct *mm, pud_t *pud,
+				      struct vm_area_struct *vma,
+				      unsigned long addr, unsigned long end)
+{
+	unsigned long next;
+	pmd_t *pmd;
+
+	pmd = pmd_offset(pud, addr);
+	do {
+		next = pmd_addr_end(addr, end);
+		if (pmd_none_or_clear_bad(pmd))
+			continue;
+		if (ipipe_pin_pte_range(mm, pmd, vma, addr, next))
+			return -ENOMEM;
+	} while (pmd++, addr = next, addr != end);
+	return 0;
+}
+
+static inline int ipipe_pin_pud_range(struct mm_struct *mm, pgd_t *pgd,
+				      struct vm_area_struct *vma,
+				      unsigned long addr, unsigned long end)
+{
+	unsigned long next;
+	pud_t *pud;
+
+	pud = pud_offset(pgd, addr);
+	do {
+		next = pud_addr_end(addr, end);
+		if (pud_none_or_clear_bad(pud))
+			continue;
+		if (ipipe_pin_pmd_range(mm, pud, vma, addr, next))
+			return -ENOMEM;
+	} while (pud++, addr = next, addr != end);
+	return 0;
+}
+
+int ipipe_disable_ondemand_mappings(struct task_struct *tsk)
+{
+	unsigned long addr, next, end;
+	struct vm_area_struct *vma;
+	struct mm_struct *mm;
+	int result = 0;
+	pgd_t *pgd;
+
+	mm = get_task_mm(tsk);
+	if (!mm)
+		return -EPERM;
+
+	down_write(&mm->mmap_sem);
+	if (mm->def_flags & VM_PINNED)
+		goto done_mm;
+
+	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+		if (!is_cow_mapping(vma->vm_flags)
+		    || !(vma->vm_flags & VM_WRITE))
+			continue;
+
+		addr = vma->vm_start;
+		end = vma->vm_end;
+
+		pgd = pgd_offset(mm, addr);
+		do {
+			next = pgd_addr_end(addr, end);
+			if (pgd_none_or_clear_bad(pgd))
+				continue;
+			if (ipipe_pin_pud_range(mm, pgd, vma, addr, next)) {
+				result = -ENOMEM;
+				goto done_mm;
+			}
+		} while (pgd++, addr = next, addr != end);
+	}
+	mm->def_flags |= VM_PINNED;
+
+  done_mm:
+	up_write(&mm->mmap_sem);
+	mmput(mm);
+	return result;
+}
+
+EXPORT_SYMBOL(ipipe_disable_ondemand_mappings);
+
+#endif
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/mm/mlock.c b/mm/mlock.c
index d35fe89..609ae26 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/mm/mlock.c
+++ b/mm/mlock.c
@@ -572,10 +572,10 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len)
 static int do_mlockall(int flags)
 {
 	struct vm_area_struct * vma, * prev = NULL;
-	unsigned int def_flags = 0;
+	unsigned int def_flags = current->mm->def_flags & VM_PINNED;
 
 	if (flags & MCL_FUTURE)
-		def_flags = VM_LOCKED;
+		def_flags |= VM_LOCKED;
 	current->mm->def_flags = def_flags;
 	if (flags == MCL_FUTURE)
 		goto out;
diff --git 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/mm/vmalloc.c b/mm/vmalloc.c
index 0380ea5..858feeb 100644
--- 38a13eddc0a76bc73ebb2fe9e73361df5d0c35ff/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -173,6 +173,9 @@ static int vmap_page_range(unsigned long start, unsigned long end,
 
 	if (unlikely(err))
 		return err;
+
+ 	__ipipe_pin_range_globally(start, end);
+
 	return nr;
 }
 
