diff --git a/Makefile b/Makefile
index 7e2750f..055ab06 100644
--- a/Makefile
+++ b/Makefile
@@ -490,6 +490,10 @@ endif
 
 include $(srctree)/arch/$(ARCH)/Makefile
 
+ifdef CONFIG_IPIPE_TRACE_MCOUNT
+CFLAGS          += -pg
+endif
+
 ifdef CONFIG_FRAME_POINTER
 CFLAGS		+= -fno-omit-frame-pointer $(call cc-option,-fno-optimize-sibling-calls,)
 else
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d6abe49..63f3f65 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -705,6 +705,8 @@ source arch/powerpc/platforms/ps3/Kconfig
 
 menu "Kernel options"
 
+source "kernel/ipipe/Kconfig"
+
 config HIGHMEM
 	bool "High memory support"
 	depends on PPC32
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 98392fb..524dc29 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -27,6 +27,14 @@ BOOTCFLAGS	:= $(HOSTCFLAGS) -fno-builtin -nostdinc -isystem \
 		   $(shell $(CROSS32CC) -print-file-name=include) -fPIC
 BOOTAFLAGS	:= -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
 
+ifdef CONFIG_IPIPE_TRACE
+# do not trace the boot loader
+nullstring :=
+space      := $(nullstring) # end of the line
+pg_flag     = $(nullstring) -pg # end of the line
+BOOTCFLAGS     := $(subst ${pg_flag},${space},${BOOTCFLAGS})
+endif
+
 ifeq ($(call cc-option-yn, -fstack-protector),y)
 BOOTCFLAGS	+= -fno-stack-protector
 endif
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d2ded19..6bc98d5 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -56,6 +56,8 @@ obj-$(CONFIG_PPC_MULTIPLATFORM)	+= prom_init.o
 obj-$(CONFIG_MODULES)		+= ppc_ksyms.o
 obj-$(CONFIG_BOOTX_TEXT)	+= btext.o
 obj-$(CONFIG_SMP)		+= smp.o
+obj-$(CONFIG_IPIPE)		+= ipipe.o
+obj-$(CONFIG_IPIPE_TRACE_MCOUNT)	+= mcount.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_PPC_UDBG_16550)	+= legacy_serial.o udbg_16550.o
 
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index b742013..fa5752a 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -1218,7 +1218,7 @@ static struct cpu_spec cpu_specs[] = {
 #endif /* CONFIG_PPC32 */
 };
 
-struct cpu_spec *identify_cpu(unsigned long offset, unsigned int pvr)
+notrace struct cpu_spec *identify_cpu(unsigned long offset, unsigned int pvr)
 {
 	struct cpu_spec *s = cpu_specs;
 	struct cpu_spec **cur = &cur_cpu_spec;
@@ -1247,7 +1247,7 @@ struct cpu_spec *identify_cpu(unsigned long offset, unsigned int pvr)
 	return NULL;
 }
 
-void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
+notrace void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
 {
 	struct fixup_entry {
 		unsigned long	mask;
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index c03e829..687a965 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -132,8 +132,23 @@ transfer_to_handler:
          * check for stack overflow
          */
 	lwz	r9,THREAD_INFO-THREAD(r12)
+#ifdef CONFIG_IPIPE
+	/* Allow for private kernel-based stacks: those must not cause
+	the stack overflow detection to trigger when some activity has
+	been preempted over them. We just check if the kernel stack is
+	not treading on the memory area ranging from
+	&current->thread_info to &current->thread, which is coarser
+	than the vanilla implementation, but likely sensitive enough
+	to catch overflows soon enough though.*/
+	addi	r12,r9,THREAD
+	cmplw	0,r1,r9
+	cmplw	1,r1,r12
+	crand	1,1,4
+	bgt-	stack_ovf		/* if r9 < r1 < r9+THREAD */
+#else /* CONFIG_IPIPE */
 	cmplw	r1,r9			/* if r1 <= current->thread_info */
 	ble-	stack_ovf		/* then the kernel stack overflowed */
+#endif /* CONFIG_IPIPE */
 5:
 #ifdef CONFIG_6xx
 	tophys(r9,r9)			/* check local flags */
@@ -198,6 +213,21 @@ _GLOBAL(DoSyscall)
 	lwz	r11,_CCR(r1)	/* Clear SO bit in CR */
 	rlwinm	r11,r11,0,4,2
 	stw	r11,_CCR(r1)
+#ifdef CONFIG_IPIPE
+	addi	r3,r1,GPR0
+	bl	__ipipe_syscall_root
+	cmpwi	r3,0
+	lwz	r3,GPR3(r1)
+	lwz	r0,GPR0(r1)
+	lwz	r4,GPR4(r1)
+	lwz	r5,GPR5(r1)
+	lwz	r6,GPR6(r1)
+	lwz	r7,GPR7(r1)
+	lwz	r8,GPR8(r1)
+	lwz	r9,GPR9(r1)
+	bgt	.ipipe_end_syscall
+	blt	ret_from_syscall
+#endif /* CONFIG_IPIPE */
 #ifdef SHOW_SYSCALLS
 	bl	do_show_syscall
 #endif /* SHOW_SYSCALLS */
@@ -260,11 +290,34 @@ syscall_exit_cont:
 	SYNC
 	RFI
 
+#ifdef CONFIG_IPIPE
+.ipipe_end_syscall:
+	LOAD_MSR_KERNEL(r10,MSR_KERNEL)	/* doesn't include MSR_EE */
+	SYNC
+	MTMSRD(r10)
+	b syscall_exit_cont
+#endif /* CONFIG_IPIPE */
+
 66:	li	r3,-ENOSYS
 	b	ret_from_syscall
 
 	.globl	ret_from_fork
 ret_from_fork:
+#ifdef CONFIG_IPIPE
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+	stwu	r1,-4(r1)
+	stw	r3,0(r1)
+	lis	r3,(0x80000000)@h
+	ori	r3,r3,(0x80000000)@l
+	bl	ipipe_trace_end
+	lwz	r3,0(r1)
+	addi	r1,r1,4
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+	LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+	ori	r10,r10,MSR_EE
+	SYNC
+	MTMSRD(r10)
+#endif /* CONFIG_IPIPE */		
 	REST_NVGPRS(r1)
 	bl	schedule_tail
 	li	r3,0
@@ -630,6 +683,11 @@ ret_from_except:
 	SYNC			/* Some chip revs have problems here... */
 	MTMSRD(r10)		/* disable interrupts */
 
+#ifdef CONFIG_IPIPE
+        bl __ipipe_check_root
+        cmpwi   r3, 0
+        beq- restore
+#endif /* CONFIG_IPIPE */
 	lwz	r3,_MSR(r1)	/* Returning to user mode? */
 	andi.	r0,r3,MSR_PR
 	beq	resume_kernel
@@ -665,11 +723,37 @@ resume_kernel:
 	beq+	restore
 	andi.	r0,r3,MSR_EE	/* interrupts off? */
 	beq	restore		/* don't schedule if so */
+#ifdef CONFIG_IPIPE	
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+	lis	r3,(0x80000000)@h
+	ori	r3,r3,(0x80000000)@l
+	bl	ipipe_trace_end
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+	LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+	ori	r10,r10,MSR_EE
+	SYNC
+	MTMSRD(r10)
+	bl	__ipipe_fast_stall_root
+#endif /* CONFIG_IPIPE */	
 1:	bl	preempt_schedule_irq
 	rlwinm	r9,r1,0,0,(31-THREAD_SHIFT)
 	lwz	r3,TI_FLAGS(r9)
 	andi.	r0,r3,_TIF_NEED_RESCHED
 	bne-	1b
+#ifdef CONFIG_IPIPE	
+	bl	__ipipe_fast_unstall_root
+	LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+	SYNC
+	MTMSRD(r10)
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+	lwz	r3,_MSR(r1)
+	andi.	r0,r3,MSR_EE
+	bne	restore
+	lis	r3,(0x80000000)@h
+	ori	r3,r3,(0x80000000)@l
+	bl	ipipe_trace_begin
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+#endif /* CONFIG_IPIPE */	
 #else
 resume_kernel:
 #endif /* CONFIG_PREEMPT */
@@ -929,6 +1013,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_601)
 
 	.comm	ee_restarts,4
 
+#ifdef CONFIG_IPIPE
+_GLOBAL(__ipipe_ret_from_except)
+        cmpwi   r3, 0
+        bne+ ret_from_except
+        b restore
+#endif /* CONFIG_IPIPE */
+
 /*
  * PROM code for specific machines follows.  Put it
  * here so it's easy to add arch-specific sections later.
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 9417cf5..7da03a5 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -329,6 +329,12 @@ i##n:								\
 	EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full,	\
 			  ret_from_except_full)
 
+#ifdef CONFIG_IPIPE
+#define EXC_XFER_IPIPE(n, hdlr)		\
+	EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
+			  __ipipe_ret_from_except)
+#endif /* CONFIG_IPIPE */
+
 #define EXC_XFER_LITE(n, hdlr)		\
 	EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
 			  ret_from_except)
@@ -418,7 +424,11 @@ InstructionAccess:
 	EXC_XFER_EE_LITE(0x400, handle_page_fault)
 
 /* External interrupt */
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x500, HardwareInterrupt, __ipipe_grab_irq, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
 	EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 /* Alignment exception */
 	. = 0x600
@@ -450,7 +460,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
 	EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
 
 /* Decrementer */
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x900, Decrementer, __ipipe_grab_timer, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
 	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index accb39d..8af68f8 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -426,8 +426,11 @@ interrupt_base:
 	/* Instruction Storage Interrupt */
 	INSTRUCTION_STORAGE_EXCEPTION
 
-	/* External Input Interrupt */
-	EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE)
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x0500, ExternalInput, __ipipe_grab_irq, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
+ 	EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 	/* Alignment Interrupt */
 	ALIGNMENT_EXCEPTION
diff --git a/arch/powerpc/kernel/head_4xx.S b/arch/powerpc/kernel/head_4xx.S
index adc7f80..9d96de7 100644
--- a/arch/powerpc/kernel/head_4xx.S
+++ b/arch/powerpc/kernel/head_4xx.S
@@ -228,6 +228,12 @@ label:
 	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
 			  ret_from_except_full)
 
+#ifdef CONFIG_IPIPE
+#define EXC_XFER_IPIPE(n, hdlr)		\
+	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
+			  __ipipe_ret_from_except)
+#endif /* CONFIG_IPIPE */
+
 #define EXC_XFER_LITE(n, hdlr)		\
 	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
 			  ret_from_except)
@@ -396,7 +402,11 @@ label:
 	EXC_XFER_EE_LITE(0x400, handle_page_fault)
 
 /* 0x0500 - External Interrupt Exception */
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x0500, HardwareInterrupt, __ipipe_grab_irq, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
 	EXCEPTION(0x0500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 /* 0x0600 - Alignment Exception */
 	START_EXCEPTION(0x0600, Alignment)
@@ -434,7 +444,11 @@ label:
 	lis	r0,TSR_PIS@h
 	mtspr	SPRN_TSR,r0		/* Clear the PIT exception */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_IPIPE
+	EXC_XFER_IPIPE(0x1000, __ipipe_grab_timer)
+#else /* !CONFIG_IPIPE */
 	EXC_XFER_LITE(0x1000, timer_interrupt)
+#endif /* CONFIG_IPIPE */
 
 #if 0
 /* NOTE:
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 901be47..c393c7b 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -187,6 +187,12 @@ i##n:								\
 	EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full,	\
 			  ret_from_except_full)
 
+#ifdef CONFIG_IPIPE
+#define EXC_XFER_IPIPE(n, hdlr)		\
+	EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
+			  __ipipe_ret_from_except)
+#endif /* CONFIG_IPIPE */
+ 
 #define EXC_XFER_LITE(n, hdlr)		\
 	EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
 			  ret_from_except)
@@ -238,7 +244,11 @@ InstructionAccess:
 	EXC_XFER_EE_LITE(0x400, handle_page_fault)
 
 /* External interrupt */
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x500, HardwareInterrupt, __ipipe_grab_irq, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
 	EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 /* Alignment exception */
 	. = 0x600
@@ -259,7 +269,11 @@ Alignment:
 	EXCEPTION(0x800, FPUnavailable, unknown_exception, EXC_XFER_STD)
 
 /* Decrementer */
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x900, Decrementer, __ipipe_grab_timer, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 	EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
 	EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 8536e76..8a2ae17 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -187,6 +187,12 @@ label:
 	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
 			  ret_from_except_full)
 
+#ifdef CONFIG_IPIPE
+#define EXC_XFER_IPIPE(n, hdlr)		\
+	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
+			  __ipipe_ret_from_except)
+#endif /* CONFIG_IPIPE */
+
 #define EXC_XFER_LITE(n, hdlr)		\
 	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
 			  ret_from_except)
@@ -345,6 +351,15 @@ label:
 	addi	r3,r1,STACK_FRAME_OVERHEAD;				      \
 	EXC_XFER_STD(0x0700, program_check_exception)
 
+#ifdef CONFIG_IPIPE
+#define DECREMENTER_EXCEPTION						      \
+	START_EXCEPTION(Decrementer)					      \
+	NORMAL_EXCEPTION_PROLOG;					      \
+	lis     r0,TSR_DIS@h;           /* Setup the DEC interrupt mask */    \
+	mtspr   SPRN_TSR,r0;		/* Clear the DEC interrupt */	      \
+	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
+	EXC_XFER_IPIPE(0x0900, __ipipe_grab_timer)
+#else /* !CONFIG_IPIPE */
 #define DECREMENTER_EXCEPTION						      \
 	START_EXCEPTION(Decrementer)					      \
 	NORMAL_EXCEPTION_PROLOG;					      \
@@ -352,6 +367,7 @@ label:
 	mtspr   SPRN_TSR,r0;		/* Clear the DEC interrupt */	      \
 	addi    r3,r1,STACK_FRAME_OVERHEAD;				      \
 	EXC_XFER_LITE(0x0900, timer_interrupt)
+#endif /* CONFIG_IPIPE */
 
 #define FP_UNAVAILABLE_EXCEPTION					      \
 	START_EXCEPTION(FloatingPointUnavailable)			      \
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 66877bd..1846753 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -526,7 +526,11 @@ interrupt_base:
 	INSTRUCTION_STORAGE_EXCEPTION
 
 	/* External Input Interrupt */
+#ifdef CONFIG_IPIPE
+	EXCEPTION(0x0500, ExternalInput, __ipipe_grab_irq, EXC_XFER_IPIPE)
+#else /* !CONFIG_IPIPE */
 	EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE)
+#endif /* CONFIG_IPIPE */
 
 	/* Alignment Interrupt */
 	ALIGNMENT_EXCEPTION
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index 8994af3..5a80ada 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -58,6 +58,7 @@ void cpu_idle(void)
 	while (1) {
 		while (!need_resched() && !cpu_should_die()) {
 			ppc64_runlatch_off();
+			ipipe_suspend_domain();
 
 			if (ppc_md.power_save) {
 				clear_thread_flag(TIF_POLLING_NRFLAG);
@@ -66,13 +67,13 @@ void cpu_idle(void)
 				 * is ordered w.r.t. need_resched() test.
 				 */
 				smp_mb();
-				local_irq_disable();
+				local_irq_disable_hw();
 
 				/* check again after disabling irqs */
 				if (!need_resched() && !cpu_should_die())
 					ppc_md.power_save();
 
-				local_irq_enable();
+				local_irq_enable_hw();
 				set_thread_flag(TIF_POLLING_NRFLAG);
 
 			} else {
diff --git a/arch/powerpc/kernel/io.c b/arch/powerpc/kernel/io.c
index 34ae114..10ea724 100644
--- a/arch/powerpc/kernel/io.c
+++ b/arch/powerpc/kernel/io.c
@@ -120,7 +120,7 @@ EXPORT_SYMBOL(_outsl_ns);
 
 #define IO_CHECK_ALIGN(v,a) ((((unsigned long)(v)) & ((a) - 1)) == 0)
 
-void _memset_io(volatile void __iomem *addr, int c, unsigned long n)
+notrace void _memset_io(volatile void __iomem *addr, int c, unsigned long n)
 {
 	void *p = (void __force *)addr;
 	u32 lc = c;
diff --git a/arch/powerpc/kernel/ipipe.c b/arch/powerpc/kernel/ipipe.c
new file mode 100644
index 0000000..8dee9c8
--- /dev/null
+++ b/arch/powerpc/kernel/ipipe.c
@@ -0,0 +1,649 @@
+/* -*- linux-c -*-
+ * linux/arch/powerpc/kernel/ipipe.c
+ *
+ * Copyright (C) 2002-2007 Philippe Gerum.
+ * Copyright (C) 2004 Wolfgang Grandegger (Adeos/ppc port over 2.4).
+ * Copyright (C) 2005 Heikki Lindholm (PowerPC 970 fixes).
+ *
+ * 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-dependent I-PIPE core support for PowerPC.
+ */
+
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <asm/system.h>
+#include <asm/machdep.h>
+#include <asm/atomic.h>
+#include <asm/hardirq.h>
+#include <asm/io.h>
+#include <asm/time.h>
+
+/* Current reload value for the decrementer. */
+unsigned long __ipipe_decr_ticks;
+
+/* Next tick date (timebase value). */
+unsigned long long __ipipe_decr_next[IPIPE_NR_CPUS];
+
+struct pt_regs __ipipe_tick_regs[IPIPE_NR_CPUS];
+
+static void __ipipe_do_IRQ(unsigned irq, void *cookie);
+
+static void __ipipe_do_timer(unsigned irq, void *cookie);
+
+#ifdef CONFIG_SMP
+
+static cpumask_t __ipipe_cpu_sync_map;
+
+static cpumask_t __ipipe_cpu_lock_map;
+
+static ipipe_spinlock_t __ipipe_cpu_barrier = IPIPE_SPIN_LOCK_UNLOCKED;
+
+static atomic_t __ipipe_critical_count = ATOMIC_INIT(0);
+
+static void (*__ipipe_cpu_sync) (void);
+
+void __ipipe_hook_critical_ipi(struct ipipe_domain *ipd)
+{
+	BUG();	/* SMP not fully implemented yet. */
+}
+
+/* Always called with hw interrupts off. */
+
+void __ipipe_do_critical_sync(unsigned irq)
+{
+	ipipe_declare_cpuid;
+
+	ipipe_load_cpuid();
+
+	cpu_set(cpuid, __ipipe_cpu_sync_map);
+
+	/*
+	 * Now we are in sync with the lock requestor running on another
+	 * CPU. Enter a spinning wait until he releases the global
+	 * lock.
+	 */
+	spin_lock_hw(&__ipipe_cpu_barrier);
+
+	/* Got it. Now get out. */
+
+	if (__ipipe_cpu_sync)
+		/* Call the sync routine if any. */
+		__ipipe_cpu_sync();
+
+	spin_unlock_hw(&__ipipe_cpu_barrier);
+
+	cpu_clear(cpuid, __ipipe_cpu_sync_map);
+}
+
+#endif	/* CONFIG_SMP */
+
+/*
+ * ipipe_critical_enter() -- Grab the superlock excluding all CPUs
+ * but the current one from a critical section. This lock is used when
+ * we must enforce a global critical section for a single CPU in a
+ * possibly SMP system whichever context the CPUs are running.
+ */
+unsigned long ipipe_critical_enter(void (*syncfn) (void))
+{
+	unsigned long flags;
+
+	local_irq_save_hw(flags);
+
+#ifdef CONFIG_SMP
+	if (num_online_cpus() > 1) {	/* We might be running a SMP-kernel on a UP box... */
+		ipipe_declare_cpuid;
+		cpumask_t lock_map;
+
+		ipipe_load_cpuid();
+
+		if (!cpu_test_and_set(cpuid, __ipipe_cpu_lock_map)) {
+			while (cpu_test_and_set(BITS_PER_LONG - 1,
+						__ipipe_cpu_lock_map)) {
+				int n = 0;
+				do {
+					cpu_relax();
+				} while (++n < cpuid);
+			}
+
+			spin_lock_hw(&__ipipe_cpu_barrier);
+
+			__ipipe_cpu_sync = syncfn;
+
+			/* Send the sync IPI to all processors but the current one. */
+			send_IPI_allbutself(IPIPE_CRITICAL_VECTOR);
+
+			cpus_andnot(lock_map, cpu_online_map,
+				    __ipipe_cpu_lock_map);
+
+			while (!cpus_equal(__ipipe_cpu_sync_map, lock_map))
+				cpu_relax();
+		}
+
+		atomic_inc(&__ipipe_critical_count);
+	}
+#endif	/* CONFIG_SMP */
+
+	return flags;
+}
+
+/* ipipe_critical_exit() -- Release the superlock. */
+
+void ipipe_critical_exit(unsigned long flags)
+{
+#ifdef CONFIG_SMP
+	if (num_online_cpus() > 1) {	/* We might be running a SMP-kernel on a UP box... */
+		ipipe_declare_cpuid;
+
+		ipipe_load_cpuid();
+
+		if (atomic_dec_and_test(&__ipipe_critical_count)) {
+			spin_unlock_hw(&__ipipe_cpu_barrier);
+
+			while (!cpus_empty(__ipipe_cpu_sync_map))
+				cpu_relax();
+
+			cpu_clear(cpuid, __ipipe_cpu_lock_map);
+			cpu_clear(BITS_PER_LONG - 1, __ipipe_cpu_lock_map);
+		}
+	}
+#endif	/* CONFIG_SMP */
+
+	local_irq_restore_hw(flags);
+}
+
+void __ipipe_init_platform(void)
+{
+	unsigned timer_virq;
+
+	/*
+	 * Allocate a virtual IRQ for the decrementer trap early to
+	 * get it mapped to IPIPE_VIRQ_BASE
+	 */
+
+	timer_virq = ipipe_alloc_virq();
+
+	if (timer_virq != IPIPE_TIMER_VIRQ)
+		panic("I-pipe: cannot reserve timer virq #%d (got #%d)",
+		      IPIPE_TIMER_VIRQ, timer_virq);
+
+	__ipipe_decr_ticks = tb_ticks_per_jiffy;
+}
+
+int __ipipe_ack_irq(unsigned irq)
+{
+	irq_desc_t *desc = irq_desc + irq;
+	desc->ipipe_ack(irq, desc);
+	return 1;
+}
+
+void __ipipe_enable_irqdesc(unsigned irq)
+{
+	irq_desc[irq].status &= ~IRQ_DISABLED;
+}
+
+static void __ipipe_enable_sync(void)
+{
+	__ipipe_decr_next[ipipe_processor_id()] =
+		__ipipe_read_timebase() + get_dec();
+}
+
+/*
+ * __ipipe_enable_pipeline() -- We are running on the boot CPU, hw
+ * interrupts are off, and secondary CPUs are still lost in space.
+ */
+void __ipipe_enable_pipeline(void)
+{
+	unsigned long flags;
+	unsigned irq;
+
+	flags = ipipe_critical_enter(&__ipipe_enable_sync);
+
+	/* First, virtualize all interrupts from the root domain. */
+
+	for (irq = 0; irq < NR_IRQS; irq++)
+		ipipe_virtualize_irq(ipipe_root_domain,
+				     irq,
+				     &__ipipe_do_IRQ, NULL,
+				     &__ipipe_ack_irq,
+				     IPIPE_HANDLE_MASK | IPIPE_PASS_MASK);
+
+	/*
+	 * We use a virtual IRQ to handle the timer irq (decrementer trap)
+	 * which has been allocated early in __ipipe_init_platform().
+	 */
+
+	ipipe_virtualize_irq(ipipe_root_domain,
+			     IPIPE_TIMER_VIRQ,
+			     &__ipipe_do_timer, NULL,
+			     NULL, IPIPE_HANDLE_MASK | IPIPE_PASS_MASK);
+
+
+	__ipipe_decr_next[ipipe_processor_id()] =
+		__ipipe_read_timebase() + get_dec();
+
+	ipipe_critical_exit(flags);
+}
+
+int ipipe_get_sysinfo(struct ipipe_sysinfo *info)
+{
+	info->ncpus = num_online_cpus();
+	info->cpufreq = ipipe_cpu_freq();
+	info->archdep.tmirq = IPIPE_TIMER_VIRQ;
+	info->archdep.tmfreq = info->cpufreq;
+
+	return 0;
+}
+
+/*
+ * ipipe_trigger_irq() -- Push the interrupt at front of the pipeline
+ * just like if it has been actually received from a hw source. Also
+ * works for virtual interrupts.
+ */
+int ipipe_trigger_irq(unsigned irq)
+{
+	unsigned long flags;
+
+	if (irq >= IPIPE_NR_IRQS ||
+	    (ipipe_virtual_irq_p(irq)
+	     && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)))
+		return -EINVAL;
+
+	local_irq_save_hw(flags);
+
+	__ipipe_handle_irq(irq, NULL);
+
+	local_irq_restore_hw(flags);
+
+	return 1;
+}
+
+static void __ipipe_set_decr(void)
+{
+	ipipe_declare_cpuid;
+
+	ipipe_load_cpuid();
+
+	disarm_decr[cpuid] = (__ipipe_decr_ticks != tb_ticks_per_jiffy);
+#ifdef CONFIG_40x
+	/* Enable and set auto-reload. */
+	mtspr(SPRN_TCR, mfspr(SPRN_TCR) | TCR_ARE);
+	mtspr(SPRN_PIT, __ipipe_decr_ticks);
+#else	/* !CONFIG_40x */
+	__ipipe_decr_next[cpuid] = __ipipe_read_timebase() + __ipipe_decr_ticks;
+	set_dec(__ipipe_decr_ticks);
+#endif	/* CONFIG_40x */
+}
+
+int ipipe_tune_timer(unsigned long ns, int flags)
+{
+	unsigned long x, ticks;
+
+	if (flags & IPIPE_RESET_TIMER)
+		ticks = tb_ticks_per_jiffy;
+	else {
+		ticks = (ns / 1000) * tb_ticks_per_jiffy / (1000000 / HZ);
+
+		if (ticks > tb_ticks_per_jiffy)
+			return -EINVAL;
+	}
+
+	x = ipipe_critical_enter(&__ipipe_set_decr);	/* Sync with all CPUs */
+	__ipipe_decr_ticks = ticks;
+	__ipipe_set_decr();
+	ipipe_critical_exit(x);
+
+	return 0;
+}
+
+/*
+ * __ipipe_handle_irq() -- IPIPE's generic IRQ handler. An optimistic
+ * interrupt protection log is maintained here for each domain. Hw
+ * interrupts are off on entry.
+ */
+void __ipipe_handle_irq(int irq, struct pt_regs *regs)
+{
+	struct ipipe_domain *this_domain, *next_domain;
+	struct list_head *head, *pos;
+	ipipe_declare_cpuid;
+	int m_ack;
+
+	m_ack = (regs == NULL);	/* Software-triggered IRQs do not need
+				 * any ack. */
+	if (irq >= IPIPE_NR_IRQS) {
+		printk(KERN_ERR "I-pipe: spurious interrupt %d\n", irq);
+		return;
+	}
+
+	ipipe_load_cpuid();
+
+	this_domain = per_cpu(ipipe_percpu_domain, cpuid);
+
+	if (unlikely(test_bit(IPIPE_STICKY_FLAG, &this_domain->irqs[irq].control)))
+		head = &this_domain->p_link;
+	else {
+		head = __ipipe_pipeline.next;
+		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);
+			if (likely(__ipipe_dispatch_wired(next_domain, irq)))
+			    goto finalize;
+			return;
+		}
+	}
+
+	/* 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.
+			 */
+
+			next_domain->cpudata[cpuid].irq_counters[irq].total_hits++;
+			next_domain->cpudata[cpuid].irq_counters[irq].pending_hits++;
+			__ipipe_set_irq_bit(next_domain, cpuid, irq);
+
+			/*
+			 * Always get the first master acknowledge available.
+			 * Once we've got it, allow slave acknowledge
+			 * handlers to run (until one of them stops us).
+			 */
+			if (next_domain->irqs[irq].acknowledge != NULL && !m_ack)
+				m_ack = next_domain->irqs[irq].acknowledge(irq);
+		}
+
+		/*
+		 * 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;
+	}
+
+finalize:
+	/*
+	 * Now walk the pipeline, yielding control to the highest
+	 * priority domain that has pending interrupt(s) or
+	 * 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.
+	 */
+
+	__ipipe_walk_pipeline(head, cpuid);
+}
+
+int __ipipe_grab_irq(struct pt_regs *regs)
+{
+	extern int ppc_spurious_interrupts;
+	ipipe_declare_cpuid;
+	int irq;
+
+	irq = ppc_md.get_irq();
+
+	if (irq != NO_IRQ && irq != NO_IRQ_IGNORE) {
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+		ipipe_trace_begin(irq);
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+		__ipipe_handle_irq(irq, regs);
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+		ipipe_trace_end(irq);
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+	} else if (irq != NO_IRQ_IGNORE)
+		ppc_spurious_interrupts++;
+
+	ipipe_load_cpuid();
+
+	return (per_cpu(ipipe_percpu_domain, cpuid) == ipipe_root_domain &&
+		!test_bit(IPIPE_STALL_FLAG,
+			  &ipipe_root_domain->cpudata[cpuid].status));
+}
+
+static void __ipipe_do_IRQ(unsigned irq, void *cookie)
+{
+	struct pt_regs *old_regs;
+#ifdef CONFIG_IRQSTACKS
+	struct thread_info *curtp, *irqtp;
+#endif
+
+	/* Provide a valid register frame, even if not the exact one. */
+	old_regs = set_irq_regs(__ipipe_tick_regs + smp_processor_id());
+
+	irq_enter();
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+	/* Debugging check for stack overflow: is there less than 2KB free? */
+	{
+		long sp;
+
+		sp = __get_SP() & (THREAD_SIZE-1);
+
+		if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
+			printk("do_IRQ: stack overflow: %ld\n",
+				sp - sizeof(struct thread_info));
+			dump_stack();
+		}
+	}
+#endif
+
+#ifdef CONFIG_IRQSTACKS
+		/* Switch to the irq stack to handle this */
+		curtp = current_thread_info();
+		irqtp = hardirq_ctx[smp_processor_id()];
+		if (curtp != irqtp) {
+			struct irq_desc *desc = irq_desc + irq;
+			void *handler = desc->handle_irq;
+			if (handler == NULL)
+				handler = &__do_IRQ;
+			irqtp->task = curtp->task;
+			irqtp->flags = 0;
+			call_handle_irq(irq, desc, irqtp, handler);
+			irqtp->task = NULL;
+			if (irqtp->flags)
+				set_bits(irqtp->flags, &curtp->flags);
+		} else
+#endif
+			generic_handle_irq(irq);
+
+	irq_exit();
+
+	set_irq_regs(old_regs);
+}
+
+static void __ipipe_do_timer(unsigned irq, void *cookie)
+{
+	timer_interrupt(__ipipe_tick_regs + smp_processor_id());
+}
+
+int __ipipe_grab_timer(struct pt_regs *regs)
+{
+	ipipe_declare_cpuid;
+
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+	ipipe_trace_begin(IPIPE_TIMER_VIRQ);
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+
+#ifdef CONFIG_POWER4
+	/* On 970 CPUs DEC cannot be disabled, and without setting DEC
+	 * here, DEC interrupt would be triggered as soon as interrupts
+	 * are enabled in __ipipe_sync_stage
+	 */
+	set_dec(0x7fffffff);
+#endif
+
+	__ipipe_tick_regs[cpuid].msr = regs->msr; /* for timer_interrupt() */
+
+#ifndef CONFIG_40x
+	if (__ipipe_decr_ticks != tb_ticks_per_jiffy) {
+		unsigned long long next_date, now;
+
+		next_date = __ipipe_decr_next[cpuid];
+
+		while ((now = __ipipe_read_timebase()) >= next_date)
+			next_date += __ipipe_decr_ticks;
+
+		set_dec(next_date - now);
+
+		__ipipe_decr_next[cpuid] = next_date;
+	}
+#endif	/* !CONFIG_40x */
+
+	__ipipe_handle_irq(IPIPE_TIMER_VIRQ, NULL);
+
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+	ipipe_trace_end(IPIPE_TIMER_VIRQ);
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+
+	ipipe_load_cpuid();
+
+	return (per_cpu(ipipe_percpu_domain, cpuid) == ipipe_root_domain &&
+		!test_bit(IPIPE_STALL_FLAG,
+			  &ipipe_root_domain->cpudata[cpuid].status));
+}
+
+int __ipipe_check_root(struct pt_regs *regs)
+{
+	ipipe_declare_cpuid;
+	/*
+	 * This routine is called with hw interrupts off, so no migration
+	 * can occur while checking the identity of the current domain.
+	 */
+	ipipe_load_cpuid();
+	return per_cpu(ipipe_percpu_domain, cpuid) == ipipe_root_domain;
+}
+
+void __ipipe_fast_stall_root(void)
+{
+	ipipe_declare_cpuid;
+	unsigned long flags;
+
+	ipipe_get_cpu(flags); /* Care for migration. */
+
+	set_bit(IPIPE_STALL_FLAG,
+		&ipipe_root_domain->cpudata[cpuid].status);
+
+	ipipe_put_cpu(flags);
+}
+
+void __ipipe_fast_unstall_root(void)
+{
+	ipipe_declare_cpuid;
+	unsigned long flags;
+
+	ipipe_get_cpu(flags); /* Care for migration. */
+
+	clear_bit(IPIPE_STALL_FLAG,
+		  &ipipe_root_domain->cpudata[cpuid].status);
+
+	ipipe_put_cpu(flags);
+}
+
+int __ipipe_syscall_root(struct pt_regs *regs)
+{
+	ipipe_declare_cpuid;
+	unsigned long flags;
+
+	/*
+	 * This routine either returns:
+	 * 0 -- if the syscall is to be passed to Linux;
+	 * >0 -- if the syscall should not be passed to Linux, and no
+	 * tail work should be performed;
+	 * <0 -- if the syscall should not be passed to Linux but the
+	 * tail work has to be performed (for handling signals etc).
+	 */
+
+	if (__ipipe_syscall_watched_p(current, regs->gpr[0]) &&
+	    __ipipe_event_monitored_p(IPIPE_EVENT_SYSCALL) &&
+	    __ipipe_dispatch_event(IPIPE_EVENT_SYSCALL,regs) > 0) {
+		if (ipipe_current_domain == ipipe_root_domain && !in_atomic()) {
+			/*
+			 * Sync pending VIRQs before _TIF_NEED_RESCHED
+			 * is tested.
+			 */
+			ipipe_lock_cpu(flags);
+			if ((ipipe_root_domain->cpudata[cpuid].irq_pending_hi & IPIPE_IRQMASK_VIRT) != 0)
+				__ipipe_sync_pipeline(IPIPE_IRQMASK_VIRT);
+			ipipe_unlock_cpu(flags);
+			return -1;
+		}
+		return 1;
+	}
+
+	return 0;
+}
+
+int __ipipe_pin_range_mapping(struct mm_struct *mm,
+			      unsigned long start, unsigned long end)
+{
+	/* Actually, we don't need this for this arch (yet?). */
+	return 0;
+}
+
+EXPORT_SYMBOL(__ipipe_decr_ticks);
+EXPORT_SYMBOL(__ipipe_decr_next);
+EXPORT_SYMBOL(ipipe_critical_enter);
+EXPORT_SYMBOL(ipipe_critical_exit);
+EXPORT_SYMBOL(ipipe_trigger_irq);
+EXPORT_SYMBOL(ipipe_get_sysinfo);
+EXPORT_SYMBOL(ipipe_tune_timer);
+
+void atomic_set_mask(unsigned long mask,
+		     unsigned long *ptr);
+
+void atomic_clear_mask(unsigned long mask,
+		       unsigned long *ptr);
+
+extern unsigned long context_map[];
+
+EXPORT_SYMBOL(disarm_decr);
+EXPORT_SYMBOL_GPL(__switch_to);
+EXPORT_SYMBOL_GPL(show_stack);
+EXPORT_SYMBOL_GPL(atomic_set_mask);
+EXPORT_SYMBOL_GPL(atomic_clear_mask);
+EXPORT_SYMBOL_GPL(context_map);
+EXPORT_SYMBOL_GPL(_switch);
+EXPORT_SYMBOL_GPL(last_task_used_math);
+#ifdef FEW_CONTEXTS
+EXPORT_SYMBOL_GPL(nr_free_contexts);
+EXPORT_SYMBOL_GPL(context_mm);
+EXPORT_SYMBOL_GPL(steal_context);
+#endif
+
+#ifdef CONFIG_IPIPE_TRACE_MCOUNT
+void notrace _mcount(void);
+EXPORT_SYMBOL(_mcount);
+#endif /* CONFIG_IPIPE_TRACE_MCOUNT */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 0bd8c76..8342a77 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -70,7 +70,7 @@
 #endif
 
 int __irq_offset_value;
-static int ppc_spurious_interrupts;
+int ppc_spurious_interrupts;
 
 #ifdef CONFIG_PPC32
 EXPORT_SYMBOL(__irq_offset_value);
diff --git a/arch/powerpc/kernel/mcount.S b/arch/powerpc/kernel/mcount.S
new file mode 100644
index 0000000..83faab8
--- /dev/null
+++ b/arch/powerpc/kernel/mcount.S
@@ -0,0 +1,75 @@
+/*
+ *  linux/arch/powerpc/kernel/mcount.S
+ *
+ *  Adapted from glibc's ppc32 profiling support --rpm.
+ */
+
+#include <asm/page.h>
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+
+/*
+ * Excerpt from sysdeps/powerpc/powerpc32/ppc-mcount.S
+ *
+ * Do profiling as described in the SYSV ELF ABI, _mcount is called
+ * with the address of a data word in r0 (that is different for every
+ * routine, initialised to 0, and otherwise unused).  The caller has
+ * put the address the caller will return to in the usual place on the stack,
+ * 4(r1).  _mcount is responsible for ensuring that when it returns no
+ * argument-passing registers are disturbed, and that the LR is set back
+ * to (what the caller sees as) 4(r1).
+ *
+ * This is intended so that the following code can be inserted at the
+ * front of any routine without changing the routine:
+ *
+ *	mflr	r0
+ *	lis	r12,0b@ha
+ *	stw	r0,4(r1)
+ *	addi	r0,r12,0b@l
+ *	bl	_mcount
+ */
+
+.globl	_mcount
+_mcount:
+	stwu	r1,-48(r1)
+/* We need to save the parameter-passing registers.  */
+	stw	r3, 12(r1)
+	stw	r4, 16(r1)
+	stw	r5, 20(r1)
+	stw	r6, 24(r1)
+	stw	r7, 28(r1)
+	stw	r8, 32(r1)
+	stw	r9, 36(r1)
+	stw	r10,40(r1)
+	mflr	r4
+	mfcr	r5
+	stw	r4, 44(r1)
+	stw	r5,  8(r1)
+	tophys(r0,0)
+	addis	r6,r0,ipipe_trace_enable@ha
+	lwz	r3,ipipe_trace_enable@l(r6)
+	cmpwi	r3,0
+	beq	1f
+	li	r3,0
+	lwz	r5, 52(r1)
+	li	r6,0
+	bl	__ipipe_trace
+1:	
+ /* Restore the registers...  */
+	lwz     r6,  8(r1)
+	lwz	r0, 44(r1)
+	lwz	r3, 12(r1)
+	mtctr	r0
+	lwz	r4, 16(r1)
+	mtcrf	0xff,r6
+	lwz	r5, 20(r1)
+	lwz	r6, 24(r1)
+	lwz	r0, 52(r1)
+	lwz	r7, 28(r1)
+	lwz	r8, 32(r1)
+	mtlr	r0
+	lwz	r9, 36(r1)
+	lwz	r10,40(r1)
+ /* ...unwind the stack frame, and return to your usual programming.  */
+	addi	r1,r1,48
+	bctr
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 61c65d1..82c1141 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -84,7 +84,7 @@ int ucache_bsize;
  * from the address that it was linked at, so we must use RELOC/PTRRELOC
  * to access static data (including strings).  -- paulus
  */
-unsigned long __init early_init(unsigned long dt_ptr)
+unsigned long notrace __init early_init(unsigned long dt_ptr)
 {
 	unsigned long offset = reloc_offset();
 	struct cpu_spec *spec;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index f6f0c6b..098de1d 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -74,6 +74,8 @@
 #endif
 #include <asm/smp.h>
 
+unsigned long disarm_decr[NR_CPUS];
+
 /* keep track of when we need to update the rtc */
 time_t last_rtc_update;
 #ifdef CONFIG_PPC_ISERIES
@@ -625,7 +627,9 @@ void timer_interrupt(struct pt_regs * regs)
 #endif
 
 	old_regs = set_irq_regs(regs);
+#ifndef CONFIG_IPIPE
 	irq_enter();
+#endif
 
 	profile_tick(CPU_PROFILING);
 	calculate_steal_time();
@@ -651,7 +655,11 @@ void timer_interrupt(struct pt_regs * regs)
 		 * is the case.
 		 */
 		if (!cpu_is_offline(cpu))
+#ifdef CONFIG_IPIPE
+			account_process_time(__ipipe_tick_regs + cpu);
+#else
 			account_process_time(regs);
+#endif
 
 		/*
 		 * No need to check whether cpu is offline here; boot_cpuid
@@ -672,7 +680,8 @@ void timer_interrupt(struct pt_regs * regs)
 	}
 	
 	next_dec = tb_ticks_per_jiffy - ticks;
-	set_dec(next_dec);
+	if ( !disarm_decr[cpu] )
+	    set_dec(next_dec);
 
 #ifdef CONFIG_PPC_ISERIES
 	if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
@@ -687,7 +696,9 @@ void timer_interrupt(struct pt_regs * regs)
 	}
 #endif
 
+#ifndef CONFIG_IPIPE
 	irq_exit();
+#endif
 	set_irq_regs(old_regs);
 }
 
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 535f506..665a5e1 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -321,6 +321,9 @@ void machine_check_exception(struct pt_regs *regs)
 	int recover = 0;
 	unsigned long reason = get_mc_reason(regs);
 
+	if (ipipe_trap_notify(IPIPE_TRAP_MCE,regs))
+	    	return;
+
 	/* See if any machine dependent calls */
 	if (ppc_md.machine_check_exception)
 		recover = ppc_md.machine_check_exception(regs);
@@ -490,11 +493,17 @@ void unknown_exception(struct pt_regs *regs)
 	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 	       regs->nip, regs->msr, regs->trap);
 
+	if (ipipe_trap_notify(IPIPE_TRAP_UNKNOWN,regs))
+	    	return;
+
 	_exception(SIGTRAP, regs, 0, 0);
 }
 
 void instruction_breakpoint_exception(struct pt_regs *regs)
 {
+	if (ipipe_trap_notify(IPIPE_TRAP_IABR,regs))
+	    	return;
+
 	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
 					5, SIGTRAP) == NOTIFY_STOP)
 		return;
@@ -505,6 +514,8 @@ void instruction_breakpoint_exception(struct pt_regs *regs)
 
 void RunModeException(struct pt_regs *regs)
 {
+	if (ipipe_trap_notify(IPIPE_TRAP_RM,regs))
+	    	return;
 	_exception(SIGTRAP, regs, 0, 0);
 }
 
@@ -512,6 +523,9 @@ void __kprobes single_step_exception(struct pt_regs *regs)
 {
 	regs->msr &= ~(MSR_SE | MSR_BE);  /* Turn off 'trace' bits */
 
+	if (ipipe_trap_notify(IPIPE_TRAP_SSTEP,regs))
+	    return;
+
 	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
 					5, SIGTRAP) == NOTIFY_STOP)
 		return;
@@ -531,6 +545,8 @@ static void emulate_single_step(struct pt_regs *regs)
 {
 	if (single_stepping(regs)) {
 		clear_single_step(regs);
+		if (ipipe_trap_notify(IPIPE_TRAP_SSTEP,regs))
+		    return;
 		_exception(SIGTRAP, regs, TRAP_TRACE, 0);
 	}
 }
@@ -754,6 +770,9 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 	}
 #endif /* CONFIG_MATH_EMULATION */
 
+	if (ipipe_trap_notify(IPIPE_TRAP_PCE,regs))
+	    	return;
+
 	if (reason & REASON_FP) {
 		/* IEEE FP exception */
 		parse_fpe(regs);
@@ -801,6 +820,9 @@ void alignment_exception(struct pt_regs *regs)
 {
 	int sig, code, fixed = 0;
 
+	if (ipipe_trap_notify(IPIPE_TRAP_ALIGNMENT,regs))
+	    	return;
+
 	/* we don't implement logging of alignment exceptions */
 	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
 		fixed = fix_alignment(regs);
@@ -838,6 +860,8 @@ void nonrecoverable_exception(struct pt_regs *regs)
 {
 	printk(KERN_ERR "Non-recoverable exception at PC=%lx MSR=%lx\n",
 	       regs->nip, regs->msr);
+	if (ipipe_trap_notify(IPIPE_TRAP_NREC,regs))
+	    	return;
 	debugger(regs);
 	die("nonrecoverable exception", regs, SIGKILL);
 }
@@ -853,11 +877,16 @@ void kernel_fp_unavailable_exception(struct pt_regs *regs)
 {
 	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
 			  "%lx at %lx\n", regs->trap, regs->nip);
+	if (ipipe_trap_notify(IPIPE_TRAP_FPUNAVAIL,regs))
+	    	return;
 	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
 }
 
 void altivec_unavailable_exception(struct pt_regs *regs)
 {
+	if (ipipe_trap_notify(IPIPE_TRAP_ALTUNAVAIL,regs))
+	    	return;
+
 	if (user_mode(regs)) {
 		/* A user program has executed an altivec instruction,
 		   but this kernel doesn't support altivec. */
@@ -882,6 +911,9 @@ void SoftwareEmulation(struct pt_regs *regs)
 	extern int Soft_emulate_8xx(struct pt_regs *);
 	int errcode;
 
+	if (ipipe_trap_notify(IPIPE_TRAP_SOFTEMU,regs))
+	    	return;
+
 	CHECK_FULL_REGS(regs);
 
 	if (!user_mode(regs)) {
@@ -910,6 +942,9 @@ void SoftwareEmulation(struct pt_regs *regs)
 
 void DebugException(struct pt_regs *regs, unsigned long debug_status)
 {
+	if (ipipe_trap_notify(IPIPE_TRAP_DEBUG,regs))
+	    	return;
+
 	if (debug_status & DBSR_IC) {	/* instruction completion */
 		regs->msr &= ~MSR_DE;
 		if (user_mode(regs)) {
@@ -940,6 +975,9 @@ void altivec_assist_exception(struct pt_regs *regs)
 {
 	int err;
 
+	if (ipipe_trap_notify(IPIPE_TRAP_ALTASSIST,regs))
+	    	return;
+
 	if (!user_mode(regs)) {
 		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
 		       " at %lx\n", regs->nip);
@@ -977,8 +1015,11 @@ void CacheLockingException(struct pt_regs *regs, unsigned long address,
 	 * as priv ops, in the future we could try to do
 	 * something smarter
 	 */
-	if (error_code & (ESR_DLK|ESR_ILK))
+	if (error_code & (ESR_DLK|ESR_ILK)) {
+		if (ipipe_trap_notify(IPIPE_TRAP_CACHE,regs))
+			return;
 		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
+	}
 	return;
 }
 #endif /* CONFIG_FSL_BOOKE */
@@ -990,6 +1031,9 @@ void SPEFloatingPointException(struct pt_regs *regs)
 	int fpexc_mode;
 	int code = 0;
 
+	if (ipipe_trap_notify(IPIPE_TRAP_SPE,regs))
+	    	return;
+
 	spefscr = current->thread.spefscr;
 	fpexc_mode = current->thread.fpexc_mode;
 
@@ -1029,6 +1073,8 @@ void unrecoverable_exception(struct pt_regs *regs)
 {
 	printk(KERN_EMERG "Unrecoverable exception %lx at %lx\n",
 	       regs->trap, regs->nip);
+	if (ipipe_trap_notify(IPIPE_TRAP_NREC,regs))
+	    	return;
 	die("Unrecoverable exception", regs, SIGABRT);
 }
 
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 03aeb3a..1eb2e9e 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -160,6 +160,9 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
 	int trap = TRAP(regs);
  	int is_exec = trap == 0x400;
 
+	if (ipipe_trap_notify(IPIPE_TRAP_ACCESS,regs))
+	    	return 0;
+
 #if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
 	/*
 	 * Fortunately the bit assignments in SRR1 for an instruction
diff --git a/arch/powerpc/platforms/iseries/irq.c b/arch/powerpc/platforms/iseries/irq.c
index 5225abf..ccd3c3c 100644
--- a/arch/powerpc/platforms/iseries/irq.c
+++ b/arch/powerpc/platforms/iseries/irq.c
@@ -81,7 +81,7 @@ struct pci_event {
 	} data;
 };
 
-static DEFINE_SPINLOCK(pending_irqs_lock);
+static IPIPE_DEFINE_SPINLOCK(pending_irqs_lock);
 static int num_pending_irqs;
 static int pending_irqs[NR_IRQS];
 
diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index 39db128..c3db17f 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -63,7 +63,7 @@ static int max_irqs;
 static int max_real_irqs;
 static u32 level_mask[4];
 
-static DEFINE_SPINLOCK(pmac_pic_lock);
+static IPIPE_DEFINE_SPINLOCK(pmac_pic_lock);
 
 #define NR_MASK_WORDS	((NR_IRQS + 31) / 32)
 static unsigned long ppc_lost_interrupts[NR_MASK_WORDS];
diff --git a/arch/powerpc/platforms/ps3/interrupt.c b/arch/powerpc/platforms/ps3/interrupt.c
index 6f5de43..4aa0db1 100644
--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -318,7 +318,7 @@ struct bmp {
 		unsigned long mask;
 		unsigned long unused_2[3];
 	} __attribute__ ((packed));
-	spinlock_t lock;
+	ipipe_spinlock_t lock;
 	unsigned long ipi_debug_brk_mask;
 };
 
diff --git a/arch/powerpc/sysdev/i8259.c b/arch/powerpc/sysdev/i8259.c
index ad87adc..107a70c 100644
--- a/arch/powerpc/sysdev/i8259.c
+++ b/arch/powerpc/sysdev/i8259.c
@@ -23,7 +23,7 @@ static unsigned char cached_8259[2] = { 0xff, 0xff };
 #define cached_A1 (cached_8259[0])
 #define cached_21 (cached_8259[1])
 
-static DEFINE_SPINLOCK(i8259_lock);
+static IPIPE_DEFINE_SPINLOCK(i8259_lock);
 
 static struct device_node *i8259_node;
 static struct irq_host *i8259_host;
diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c
index 746f78c..0e57eb3 100644
--- a/arch/powerpc/sysdev/ipic.c
+++ b/arch/powerpc/sysdev/ipic.c
@@ -30,7 +30,7 @@
 #include "ipic.h"
 
 static struct ipic * primary_ipic;
-static DEFINE_SPINLOCK(ipic_lock);
+static IPIPE_DEFINE_SPINLOCK(ipic_lock);
 
 static struct ipic_info ipic_info[] = {
 	[9] = {
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index d01ced1..92ed7e6 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -44,7 +44,7 @@
 
 static struct mpic *mpics;
 static struct mpic *mpic_primary;
-static DEFINE_SPINLOCK(mpic_lock);
+static IPIPE_DEFINE_SPINLOCK(mpic_lock);
 
 #ifdef CONFIG_PPC32	/* XXX for now */
 #ifdef CONFIG_IRQ_ALL_CPUS
diff --git a/arch/powerpc/sysdev/tsi108_pci.c b/arch/powerpc/sysdev/tsi108_pci.c
index ae249c6..cde8ae9 100644
--- a/arch/powerpc/sysdev/tsi108_pci.c
+++ b/arch/powerpc/sysdev/tsi108_pci.c
@@ -249,7 +249,9 @@ static void tsi108_pci_int_mask(u_int irq)
 {
 	u_int irp_cfg;
 	int int_line = (irq - IRQ_PCI_INTAD_BASE);
+	unsigned long flags;
 
+	local_irq_save_hw_cond(flags);
 	irp_cfg = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
 	mb();
 	irp_cfg |= (1 << int_line);	/* INTx_DIR = output */
@@ -257,19 +259,23 @@ static void tsi108_pci_int_mask(u_int irq)
 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL, irp_cfg);
 	mb();
 	irp_cfg = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
+	local_irq_restore_hw_cond(flags);
 }
 
 static void tsi108_pci_int_unmask(u_int irq)
 {
 	u_int irp_cfg;
 	int int_line = (irq - IRQ_PCI_INTAD_BASE);
+	unsigned long flags;
 
+	local_irq_save_hw_cond(flags);
 	irp_cfg = tsi108_read_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL);
 	mb();
 	irp_cfg &= ~(1 << int_line);
 	irp_cfg |= (3 << (8 + (int_line * 2)));
 	tsi108_write_reg(TSI108_PCI_OFFSET + TSI108_PCI_IRP_CFG_CTL, irp_cfg);
 	mb();
+	local_irq_restore_hw_cond(flags);
 }
 
 static void init_pci_source(void)
@@ -360,6 +366,9 @@ static void tsi108_pci_irq_ack(u_int irq)
 
 static void tsi108_pci_irq_end(u_int irq)
 {
+	unsigned long flags;
+
+	local_irq_save_hw_cond(flags);
 	tsi108_pci_int_unmask(irq);
 
 	/* Enable interrupts from PCI block */
@@ -367,6 +376,7 @@ static void tsi108_pci_irq_end(u_int irq)
 			 tsi108_read_reg(TSI108_PCI_OFFSET +
 					 TSI108_PCI_IRP_ENABLE) |
 			 TSI108_PCI_IRP_ENABLE_P_INT);
+	local_irq_restore_hw_cond(flags);
 	mb();
 }
 
diff --git a/drivers/pci/htirq.c b/drivers/pci/htirq.c
index 279c940..daabf90 100644
--- a/drivers/pci/htirq.c
+++ b/drivers/pci/htirq.c
@@ -21,7 +21,7 @@
  * With multiple simultaneous hypertransport irq devices it might pay
  * to make this more fine grained.  But start with simple, stupid, and correct.
  */
-static DEFINE_SPINLOCK(ht_irq_lock);
+static IPIPE_DEFINE_SPINLOCK(ht_irq_lock);
 
 struct ht_irq_cfg {
 	struct pci_dev *dev;
diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index 3c4b6c2..f96a049 100644
--- a/drivers/serial/mpc52xx_uart.c
+++ b/drivers/serial/mpc52xx_uart.c
@@ -804,6 +804,40 @@ console_initcall(mpc52xx_console_init);
 #endif
 
 
+#ifdef CONFIG_IPIPE
+
+#include <stdarg.h>
+
+void __ipipe_serial_debug(const char *fmt, ...)
+{
+	struct console *co = MPC52xx_PSC_CONSOLE;
+	unsigned long flags, count;
+	struct uart_port *port;
+	char buf[128];
+	va_list ap;
+
+	if (co->index < 0)
+		return;		/* No console. */
+
+	port = &mpc52xx_uart_ports[co->index];
+
+	if (!port->mapbase)
+		return;		/* Too early. */
+
+	va_start(ap, fmt);
+	vsprintf(buf, fmt, ap);
+	va_end(ap);
+	count = strlen(buf);
+
+	local_irq_save_hw(flags);
+	mpc52xx_console_write(co, buf, count);
+	local_irq_restore_hw(flags);
+}
+
+EXPORT_SYMBOL(__ipipe_serial_debug);
+
+#endif
+
 /* ======================================================================== */
 /* UART Driver                                                              */
 /* ======================================================================== */
diff --git a/include/asm-powerpc/hw_irq.h b/include/asm-powerpc/hw_irq.h
index 9e4dd98..2168d31 100644
--- a/include/asm-powerpc/hw_irq.h
+++ b/include/asm-powerpc/hw_irq.h
@@ -16,6 +16,10 @@ extern void timer_interrupt(struct pt_regs *);
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>
 
+#ifdef CONFIG_IPIPE
+#error "I-pipe: arch/powerpc64 not supported yet - use an older Adeos patch."
+#endif
+
 static inline unsigned long local_get_flags(void)
 {
 	unsigned long flags;
@@ -51,17 +55,36 @@ extern void iseries_handle_interrupts(void);
 #define hard_irq_enable()	__mtmsrd(mfmsr() | MSR_EE, 1)
 #define hard_irq_disable()	__mtmsrd(mfmsr() & ~MSR_EE, 1)
 
-#else
+#else  /* !CONFIG_PPC64 */
+
+static inline unsigned long raw_mangle_irq_bits(int virt, unsigned long real)
+{
+	/* Merge virtual and real interrupt mask bits into a single
+	   32bit word. */
+	return (real & ~(1 << 31)) | ((virt != 0) << 31);
+}
 
+static inline int raw_demangle_irq_bits(unsigned long *x)
+{
+	int virt = (*x & (1 << 31)) != 0;
+	*x &= ~(1L << 31);
+	return virt;
+}
+
+#define local_save_flags_hw(flags)		((flags) = mfmsr())
+#define local_test_iflag_hw(x)			((x) & MSR_EE)
+#define irqs_disabled_hw()			((mfmsr() & MSR_EE) == 0)
+#define local_irq_save_hw_notrace(flags)	local_irq_save_ptr_hw(&flags)
+#define raw_irqs_disabled_flags(flags)		(!local_test_iflag_hw(flags))
 #if defined(CONFIG_BOOKE)
-#define SET_MSR_EE(x)	mtmsr(x)
-#define local_irq_restore(flags)	__asm__ __volatile__("wrtee %0" : : "r" (flags) : "memory")
+#define local_irq_restore_hw_notrace(flags)	\
+	__asm__ __volatile__("wrtee %0" : : "r" (flags) : "memory")
 #else
 #define SET_MSR_EE(x)	mtmsr(x)
-#define local_irq_restore(flags)	mtmsr(flags)
+#define local_irq_restore_hw_notrace(flags)	mtmsr(flags)
 #endif
 
-static inline void local_irq_disable(void)
+static inline void local_irq_disable_hw_notrace(void)
 {
 #ifdef CONFIG_BOOKE
 	__asm__ __volatile__("wrteei 0": : :"memory");
@@ -73,7 +96,7 @@ static inline void local_irq_disable(void)
 #endif
 }
 
-static inline void local_irq_enable(void)
+static inline void local_irq_enable_hw_notrace(void)
 {
 #ifdef CONFIG_BOOKE
 	__asm__ __volatile__("wrteei 1": : :"memory");
@@ -85,7 +108,7 @@ static inline void local_irq_enable(void)
 #endif
 }
 
-static inline void local_irq_save_ptr(unsigned long *flags)
+static inline void local_irq_save_ptr_hw(unsigned long *flags)
 {
 	unsigned long msr;
 	msr = mfmsr();
@@ -98,9 +121,108 @@ static inline void local_irq_save_ptr(unsigned long *flags)
 	__asm__ __volatile__("": : :"memory");
 }
 
-#define local_save_flags(flags)	((flags) = mfmsr())
-#define local_irq_save(flags)	local_irq_save_ptr(&flags)
-#define irqs_disabled()		((mfmsr() & MSR_EE) == 0)
+#ifdef CONFIG_IPIPE
+
+#include <linux/ipipe_base.h>
+
+#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
+
+#include <linux/ipipe_trace.h>
+
+static inline void local_irq_disable_hw(void)
+{
+	if (!irqs_disabled_hw()) {
+		local_irq_disable_hw_notrace();
+		ipipe_trace_begin(0x80000000);
+	}
+}
+
+static inline void local_irq_enable_hw(void)
+{
+	if (irqs_disabled_hw()) {
+		ipipe_trace_end(0x80000000);
+		local_irq_enable_hw_notrace();
+	}
+}
+
+#define local_irq_save_hw(flags) \
+do {						       \
+	local_irq_save_ptr_hw(&(flags));	       \
+	if (local_test_iflag_hw(flags))		       \
+		ipipe_trace_begin(0x80000001);	       \
+} while(0)
+
+static inline void local_irq_restore_hw(unsigned long flags)
+{
+	if (local_test_iflag_hw(flags))
+		ipipe_trace_end(0x80000001);
+
+	local_irq_restore_hw_notrace(flags);
+}
+
+#else /* !CONFIG_IPIPE_TRACE_IRQSOFF */
+
+#define local_irq_disable_hw    local_irq_disable_hw_notrace
+#define local_irq_enable_hw     local_irq_enable_hw_notrace
+#define local_irq_save_hw       local_irq_save_hw_notrace
+#define local_irq_restore_hw    local_irq_restore_hw_notrace
+
+#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
+
+static inline void local_irq_disable(void)
+{
+	ipipe_check_context(ipipe_root_domain);
+	__ipipe_stall_root();
+	barrier();
+}
+
+static inline void local_irq_enable(void)
+{
+	barrier();
+	__ipipe_unstall_root();
+}
+
+static inline void local_irq_save_ptr(unsigned long *flags)
+{
+	*flags = (!__ipipe_test_and_stall_root()) << 15;
+	barrier();
+}
+
+static inline void local_irq_restore(unsigned long flags)
+{
+	barrier();
+	__ipipe_restore_root(!(flags & MSR_EE));
+}
+
+#define local_save_flags(flags)		\
+do {						\
+	(flags) = (!__ipipe_test_root()) << 15;	\
+	barrier();				\
+} while(0)
+
+#define local_irq_save(flags)			\
+do {						\
+	ipipe_check_context(ipipe_root_domain);	\
+	local_irq_save_ptr(&flags);		\
+} while(0)
+
+#define irqs_disabled()		__ipipe_test_root()
+
+#else /* !CONFIG_IPIPE */
+
+#define local_irq_disable_hw    	local_irq_disable_hw_notrace
+#define local_irq_enable_hw     	local_irq_enable_hw_notrace
+#define local_irq_save_hw       	local_irq_save_hw_notrace
+#define local_irq_restore_hw    	local_irq_restore_hw_notrace
+#define local_irq_restore(flags)	local_irq_restore_hw(flags)
+#define local_irq_disable()		local_irq_disable_hw()
+#define local_irq_enable()		local_irq_enable_hw()
+#define local_irq_save_ptr(flags)	local_irq_save_ptr_hw(flags)
+#define irqs_disabled()			irqs_disabled_hw()
+#define local_save_flags(flags)		local_save_flags_hw(flags)
+#define local_irq_save(flags)  		local_irq_save_hw(flags)
+
+#endif /* !CONFIG_IPIPE */
 
 #define hard_irq_enable()	local_irq_enable()
 #define hard_irq_disable()	local_irq_disable()
diff --git a/include/asm-powerpc/ipipe.h b/include/asm-powerpc/ipipe.h
new file mode 100644
index 0000000..d077d5a
--- /dev/null
+++ b/include/asm-powerpc/ipipe.h
@@ -0,0 +1,219 @@
+/* -*- linux-c -*-
+ * include/asm-ppc/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 __POWERPC_IPIPE_H
+#define __POWERPC_IPIPE_H
+
+#ifdef CONFIG_IPIPE
+
+#include <asm/ptrace.h>
+#include <asm/irq.h>
+#include <asm/bitops.h>
+#include <asm/time.h>
+#include <linux/list.h>
+#include <linux/cpumask.h>
+#include <linux/threads.h>
+
+#define IPIPE_ARCH_STRING	"1.6-02"
+#define IPIPE_MAJOR_NUMBER	1
+#define IPIPE_MINOR_NUMBER	6
+#define IPIPE_PATCH_NUMBER	2
+
+#define IPIPE_NR_XIRQS		NR_IRQS
+#define IPIPE_IRQ_ISHIFT	5	/* 2^5 for 32bits arch. */
+
+/*
+ * The first virtual interrupt is reserved for the timer (see
+ * __ipipe_init_platform).
+ */
+#define IPIPE_TIMER_VIRQ	IPIPE_VIRQ_BASE
+
+#ifdef CONFIG_SMP
+#error "I-pipe/powerpc: SMP not yet implemented"
+#define ipipe_processor_id()	(current_thread_info()->cpu)
+#else /* !CONFIG_SMP */
+#define ipipe_processor_id()	0
+#endif	/* CONFIG_SMP */
+
+#define prepare_arch_switch(next)				\
+do {								\
+	ipipe_schedule_notify(current, next);			\
+	local_irq_disable_hw();					\
+} while(0)
+
+#define task_hijacked(p)					\
+	({							\
+	int x = ipipe_current_domain != ipipe_root_domain;	\
+	__clear_bit(IPIPE_SYNC_FLAG,				\
+		    &ipipe_root_domain->cpudata[task_cpu(p)].status); \
+	local_irq_enable_hw(); x;				\
+	})
+
+ /* PPC traps */
+#define IPIPE_TRAP_ACCESS	 0	/* Data or instruction access exception */
+#define IPIPE_TRAP_ALIGNMENT	 1	/* Alignment exception */
+#define IPIPE_TRAP_ALTUNAVAIL	 2	/* Altivec unavailable */
+#define IPIPE_TRAP_PCE		 3	/* Program check exception */
+#define IPIPE_TRAP_MCE		 4	/* Machine check exception */
+#define IPIPE_TRAP_UNKNOWN	 5	/* Unknown exception */
+#define IPIPE_TRAP_IABR		 6	/* Instruction breakpoint */
+#define IPIPE_TRAP_RM		 7	/* Run mode exception */
+#define IPIPE_TRAP_SSTEP	 8	/* Single-step exception */
+#define IPIPE_TRAP_NREC		 9	/* Non-recoverable exception */
+#define IPIPE_TRAP_SOFTEMU	10	/* Software emulation */
+#define IPIPE_TRAP_DEBUG	11	/* Debug exception */
+#define IPIPE_TRAP_SPE		12	/* SPE exception */
+#define IPIPE_TRAP_ALTASSIST	13	/* Altivec assist exception */
+#define IPIPE_TRAP_CACHE	14	/* Cache-locking exception (FSL) */
+#define IPIPE_TRAP_FPUNAVAIL	15	/* FP unavailable exception */
+#define IPIPE_NR_FAULTS		16
+/* Pseudo-vectors used for kernel events */
+#define IPIPE_FIRST_EVENT	IPIPE_NR_FAULTS
+#define IPIPE_EVENT_SYSCALL	(IPIPE_FIRST_EVENT)
+#define IPIPE_EVENT_SCHEDULE	(IPIPE_FIRST_EVENT + 1)
+#define IPIPE_EVENT_SIGWAKE	(IPIPE_FIRST_EVENT + 2)
+#define IPIPE_EVENT_SETSCHED	(IPIPE_FIRST_EVENT + 3)
+#define IPIPE_EVENT_INIT	(IPIPE_FIRST_EVENT + 4)
+#define IPIPE_EVENT_EXIT	(IPIPE_FIRST_EVENT + 5)
+#define IPIPE_EVENT_CLEANUP	(IPIPE_FIRST_EVENT + 6)
+#define IPIPE_LAST_EVENT	IPIPE_EVENT_CLEANUP
+#define IPIPE_NR_EVENTS		(IPIPE_LAST_EVENT + 1)
+
+struct ipipe_domain;
+
+struct ipipe_sysinfo {
+
+	int ncpus;		/* Number of CPUs on board */
+	u64 cpufreq;		/* CPU frequency (in Hz) */
+
+	/* Arch-dependent block */
+
+	struct {
+		unsigned tmirq;	/* Timer tick IRQ */
+		u64 tmfreq;	/* Timer frequency */
+	} archdep;
+};
+
+#define ipipe_read_tsc(t)					\
+	({							\
+	unsigned long __tbu;					\
+	__asm__ __volatile__ ("1: mftbu %0\n"			\
+			      "mftb %1\n"			\
+			      "mftbu %2\n"			\
+			      "cmpw %2,%0\n"			\
+			      "bne- 1b\n"			\
+			      :"=r" (((unsigned long *)&t)[0]),	\
+			      "=r" (((unsigned long *)&t)[1]),	\
+			      "=r" (__tbu));			\
+	t;							\
+	})
+
+#define __ipipe_read_timebase()					\
+	({							\
+	unsigned long long t;					\
+	ipipe_read_tsc(t);					\
+	t;							\
+	})
+
+#define ipipe_cpu_freq()	(HZ * tb_ticks_per_jiffy)
+#define ipipe_tsc2ns(t)		((((unsigned long)(t)) * 1000) / (ipipe_cpu_freq() / 1000000))
+
+#define ipipe_tsc2us(t) \
+({ \
+    unsigned long long delta = (t); \
+    do_div(delta, ipipe_cpu_freq()/1000000+1);	\
+    (unsigned long)delta; \
+})
+
+/* Private interface -- Internal use only */
+
+#define __ipipe_check_platform()	do { } while(0)
+
+#define __ipipe_enable_irq(irq)	enable_irq(irq)
+
+#define __ipipe_disable_irq(irq)	disable_irq(irq)
+
+#ifdef CONFIG_SMP
+void __ipipe_hook_critical_ipi(struct ipipe_domain *ipd);
+#else
+#define __ipipe_hook_critical_ipi(ipd) do { } while(0)
+#endif
+
+void __ipipe_enable_irqdesc(unsigned irq);
+
+void __ipipe_init_platform(void);
+
+void __ipipe_enable_pipeline(void);
+
+extern unsigned long __ipipe_decr_ticks;
+
+extern unsigned long long __ipipe_decr_next[];
+
+extern struct pt_regs __ipipe_tick_regs[];
+
+extern unsigned long disarm_decr[];
+
+void __ipipe_handle_irq(int irq,
+			struct pt_regs *regs);
+
+void __ipipe_serial_debug(const char *fmt, ...);
+
+#define __ipipe_tick_irq	IPIPE_TIMER_VIRQ
+
+static inline unsigned long __ipipe_ffnz(unsigned long ul)
+{
+	__asm__ __volatile__("cntlzw %0, %1":"=r"(ul):"r"(ul & (-ul)));
+	return 31 - ul;
+}
+
+/* When running handlers, enable hw interrupts for all domains but the
+ * one heading the pipeline, so that IRQs can never be significantly
+ * deferred for the latter. */
+#define __ipipe_run_isr(ipd, irq, cpuid)				\
+do {									\
+	local_irq_enable_nohead(ipd);					\
+	if (ipd == ipipe_root_domain)					\
+		if (likely(!ipipe_virtual_irq_p(irq)))			\
+			ipd->irqs[irq].handler(irq, NULL);		\
+		else {							\
+			irq_enter();					\
+			ipd->irqs[irq].handler(irq, ipd->irqs[irq].cookie);\
+			irq_exit();					\
+		}							\
+	else {								\
+		__clear_bit(IPIPE_SYNC_FLAG, &cpudata->status);		\
+		ipd->irqs[irq].handler(irq, ipd->irqs[irq].cookie);	\
+		__set_bit(IPIPE_SYNC_FLAG, &cpudata->status);		\
+	}								\
+	local_irq_disable_nohead(ipd);					\
+} while(0)
+
+#define __ipipe_syscall_watched_p(p, sc)	\
+	(((p)->flags & PF_EVNOTIFY) || (unsigned long)sc >= NR_syscalls)
+
+#else /* !CONFIG_IPIPE */
+
+#define task_hijacked(p)	0
+
+#endif /* CONFIG_IPIPE */
+
+#endif	/* !__POWERPC_IPIPE_H */
+
diff --git a/include/asm-ppc/mmu_context.h b/include/asm-ppc/mmu_context.h
index 2bc8589..97c291e 100644
--- a/include/asm-ppc/mmu_context.h
+++ b/include/asm-ppc/mmu_context.h
@@ -153,7 +153,10 @@ static inline int init_new_context(struct task_struct *t, struct mm_struct *mm)
  */
 static inline void destroy_context(struct mm_struct *mm)
 {
+	unsigned long flags;
+
 	preempt_disable();
+	local_irq_save_hw_cond(flags);
 	if (mm->context.id != NO_CONTEXT) {
 		clear_bit(mm->context.id, context_map);
 		mm->context.id = NO_CONTEXT;
@@ -161,6 +164,7 @@ static inline void destroy_context(struct mm_struct *mm)
 		atomic_inc(&nr_free_contexts);
 #endif
 	}
+ 	local_irq_restore_hw_cond(flags);
 	preempt_enable();
 }
 
@@ -193,7 +197,13 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  * After we have set current->mm to a new value, this activates
  * the context for the new mm so we see the new mappings.
  */
-#define activate_mm(active_mm, mm)   switch_mm(active_mm, mm, current)
+#define activate_mm(active_mm, mm)   \
+do { \
+	unsigned long flags; \
+	local_irq_save_hw_cond(flags); \
+	switch_mm(active_mm, mm, current); \
+	local_irq_restore_hw_cond(flags);	   \
+} while(0)
 
 extern void mmu_context_init(void);
 
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 612472a..2b2574c 100644
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -128,7 +128,7 @@ static inline void account_system_vtime(struct task_struct *tsk)
  */
 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 { if (ipipe_root_domain_p) { lockdep_off(); irq_enter(); } } while (0)
+#define nmi_exit()		do { if (ipipe_root_domain_p) { __irq_exit(); lockdep_on(); } } while (0)
 
 #endif /* LINUX_HARDIRQ_H */
diff --git a/include/linux/ipipe.h b/include/linux/ipipe.h
new file mode 100644
index 0000000..7282176
--- /dev/null
+++ b/include/linux/ipipe.h
@@ -0,0 +1,692 @@
+/* -*- 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 <asm/ipipe.h>
+
+#ifdef CONFIG_IPIPE
+
+#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
+
+/* 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))
+
+#ifdef CONFIG_SMP
+
+#define IPIPE_NR_CPUS		NR_CPUS
+#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)
+#define ipipe_current_domain	per_cpu(ipipe_percpu_domain, ipipe_processor_id())
+
+#else /* !CONFIG_SMP */
+
+#define IPIPE_NR_CPUS		1
+#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)
+#define ipipe_current_domain	per_cpu(ipipe_percpu_domain, 0)
+
+#endif /* CONFIG_SMP */
+
+#define ipipe_virtual_irq_p(irq)	((irq) >= IPIPE_VIRQ_BASE && \
+					 (irq) < IPIPE_NR_IRQS)
+
+typedef void (*ipipe_irq_handler_t)(unsigned irq,
+				    void *cookie);
+
+#define IPIPE_SAME_HANDLER	((ipipe_irq_handler_t)(-1))
+
+typedef int (*ipipe_irq_ackfn_t)(unsigned irq);
+
+typedef int (*ipipe_event_handler_t)(unsigned event,
+				     struct ipipe_domain *from,
+				     void *data);
+struct ipipe_domain {
+
+	struct ipcpudata {
+		unsigned long status;	/* Must be first in ipipe_domain */
+		unsigned long irq_pending_hi;
+		unsigned long irq_pending_lo[IPIPE_IRQ_IWORDS];
+		struct ipirqcnt {
+			unsigned long pending_hits;
+			unsigned long total_hits;
+		} irq_counters[IPIPE_NR_IRQS];
+		unsigned long long evsync;
+	} ____cacheline_aligned_in_smp cpudata[IPIPE_NR_CPUS];
+
+	struct {
+		unsigned long control;
+		ipipe_irq_ackfn_t acknowledge;
+		ipipe_irq_handler_t handler;
+		void *cookie;
+	} ____cacheline_aligned irqs[IPIPE_NR_IRQS];
+
+	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. */
+	unsigned long flags;
+	unsigned domid;
+	const char *name;
+	int priority;
+	void *pdd;
+	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 */
+};
+
+/* The following macros must be used hw interrupts off. */
+
+#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,cpuid,irq)	((ipd)->cpudata[cpuid].irq_counters[irq].total_hits)
+
+#define __ipipe_set_irq_bit(ipd,cpuid,irq) \
+do { \
+	if (!test_bit(IPIPE_LOCK_FLAG,&(ipd)->irqs[irq].control)) { \
+		__set_bit(irq & IPIPE_IRQ_IMASK,&(ipd)->cpudata[cpuid].irq_pending_lo[irq >> IPIPE_IRQ_ISHIFT]); \
+		__set_bit(irq >> IPIPE_IRQ_ISHIFT,&(ipd)->cpudata[cpuid].irq_pending_hi); \
+	} \
+} while(0)
+
+#define __ipipe_clear_pend(ipd,cpuid,irq) \
+do { \
+	__clear_bit(irq & IPIPE_IRQ_IMASK,&(ipd)->cpudata[cpuid].irq_pending_lo[irq >> IPIPE_IRQ_ISHIFT]); \
+	if ((ipd)->cpudata[cpuid].irq_pending_lo[irq >> IPIPE_IRQ_ISHIFT] == 0) \
+		__clear_bit(irq >> IPIPE_IRQ_ISHIFT,&(ipd)->cpudata[cpuid].irq_pending_hi); \
+} while(0)
+
+#define __ipipe_lock_irq(ipd,cpuid,irq) \
+do { \
+	if (!test_and_set_bit(IPIPE_LOCK_FLAG,&(ipd)->irqs[irq].control)) \
+		__ipipe_clear_pend(ipd,cpuid,irq); \
+} while(0)
+
+#define __ipipe_unlock_irq(ipd,irq) \
+do { \
+	int __cpuid, __nr_cpus = num_online_cpus(); \
+	if (test_and_clear_bit(IPIPE_LOCK_FLAG,&(ipd)->irqs[irq].control)) \
+		for (__cpuid = 0; __cpuid < __nr_cpus; __cpuid++) \
+			if ((ipd)->cpudata[__cpuid].irq_counters[irq].pending_hits > 0) { /* We need atomic ops next. */ \
+				set_bit(irq & IPIPE_IRQ_IMASK,&(ipd)->cpudata[__cpuid].irq_pending_lo[irq >> IPIPE_IRQ_ISHIFT]); \
+				set_bit(irq >> IPIPE_IRQ_ISHIFT,&(ipd)->cpudata[__cpuid].irq_pending_hi); \
+			} \
+} while(0)
+
+#define __ipipe_clear_irq(ipd,irq) \
+do { \
+	int __cpuid, __nr_cpus = num_online_cpus(); \
+	clear_bit(IPIPE_LOCK_FLAG,&(ipd)->irqs[irq].control); \
+	for (__cpuid = 0; __cpuid < __nr_cpus; __cpuid++) { \
+		(ipd)->cpudata[__cpuid].irq_counters[irq].pending_hits = 0; \
+		__ipipe_clear_pend(ipd,__cpuid,irq); \
+	} \
+} while(0)
+
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+#define write_lock_hw(x)		__raw_write_lock(&(x)->raw_lock)
+#define write_trylock_hw(x)		__raw_write_trylock(&(x)->raw_lock)
+#define write_unlock_hw(x)		__raw_write_unlock(&(x)->raw_lock)
+#define read_lock_hw(x)		__raw_read_lock(&(x)->raw_lock)
+#define read_trylock_hw(x)		__raw_read_trylock(&(x)->raw_lock)
+#define read_unlock_hw(x)		__raw_read_unlock(&(x)->raw_lock)
+#else /* UP non-debug */
+#define write_lock_hw(lock)		do { (void)(lock); } while (0)
+#define write_trylock_hw(lock)	({ (void)(lock); 1; })
+#define write_unlock_hw(lock)		do { (void)(lock); } while (0)
+#define read_lock_hw(lock)		do { (void)(lock); } while (0)
+#define read_trylock_hw(lock)		({ (void)(lock); 1; })
+#define read_unlock_hw(lock)		do { (void)(lock); } while (0)
+#endif /* CONFIG_SMP || CONFIG_DEBUG_SPINLOCK */
+
+typedef rwlock_t			ipipe_rwlock_t;
+#define IPIPE_RW_LOCK_UNLOCKED		RW_LOCK_UNLOCKED
+
+#define read_lock_irqsave_hw(lock, flags)	\
+do {						\
+	local_irq_save_hw(flags);		\
+	read_lock_hw(lock);			\
+} while (0)
+
+#define read_unlock_irqrestore_hw(lock, flags)	\
+do {						\
+	read_unlock_hw(lock);			\
+	local_irq_restore_hw(flags);		\
+} while (0)
+
+#define write_lock_irqsave_hw(lock, flags)	\
+do {						\
+	local_irq_save_hw(flags);		\
+	write_lock_hw(lock);			\
+} while (0)
+
+#define write_unlock_irqrestore_hw(lock, flags)	\
+do {						\
+	write_unlock_hw(lock);			\
+	local_irq_restore_hw(flags);		\
+} while (0)
+
+DECLARE_PER_CPU(struct ipipe_domain *, ipipe_percpu_domain);
+
+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 fastcall __ipipe_walk_pipeline(struct list_head *pos, int cpuid);
+
+int fastcall __ipipe_schedule_irq(unsigned irq, struct list_head *head);
+
+int fastcall __ipipe_dispatch_event(unsigned event, void *data);
+
+int fastcall __ipipe_dispatch_wired(struct ipipe_domain *head, unsigned irq);
+
+void fastcall __ipipe_sync_stage(unsigned long syncmask);
+
+void __ipipe_pin_range_globally(unsigned long start, unsigned long end);
+
+struct mm_struct;
+
+int __ipipe_pin_range_mapping(struct mm_struct *mm,
+			      unsigned long start, unsigned long end);
+
+#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 fastcall __ipipe_send_ipi(unsigned ipi,
+			      cpumask_t cpumask);
+
+#endif /* CONFIG_SMP */
+
+/* Called with hw interrupts off. */
+static inline void __ipipe_switch_to(struct ipipe_domain *out,
+				     struct ipipe_domain *in, int cpuid)
+{
+	void ipipe_suspend_domain(void);
+
+	/*
+	 * "in" is guaranteed to be closer than "out" from the head of the
+	 * pipeline (and obviously different).
+	 */
+
+	out->cpudata[cpuid].evsync = 0;
+	per_cpu(ipipe_percpu_domain, cpuid) = in;
+
+	ipipe_suspend_domain();	/* Sync stage and propagate interrupts. */
+	ipipe_load_cpuid();	/* Processor might have changed. */
+
+	if (per_cpu(ipipe_percpu_domain, cpuid) == in)
+		/*
+		 * Otherwise, something has changed the current domain under
+		 * our feet recycling the register set; do not override.
+		 */
+		per_cpu(ipipe_percpu_domain, cpuid) = out;
+}
+
+#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)		\
+({						\
+	ipipe_declare_cpuid;			\
+	int ret = 0;				\
+	ipipe_load_cpuid();			\
+	if ((test_bit(IPIPE_NOSTACK_FLAG, &ipipe_current_domain->cpudata[cpuid].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);
+}
+
+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 fastcall ipipe_trigger_irq(unsigned irq);
+
+static inline int ipipe_propagate_irq(unsigned irq)
+{
+	return __ipipe_schedule_irq(irq, ipipe_current_domain->p_link.next);
+}
+
+static inline int ipipe_schedule_irq(unsigned irq)
+{
+	return __ipipe_schedule_irq(irq, &ipipe_current_domain->p_link);
+}
+
+void fastcall ipipe_stall_pipeline_from(struct ipipe_domain *ipd);
+
+unsigned long fastcall ipipe_test_and_stall_pipeline_from(struct ipipe_domain *ipd);
+
+void fastcall ipipe_unstall_pipeline_from(struct ipipe_domain *ipd);
+
+unsigned long fastcall ipipe_test_and_unstall_pipeline_from(struct ipipe_domain *ipd);
+
+void fastcall ipipe_restore_pipeline_from(struct ipipe_domain *ipd,
+					  unsigned long x);
+
+static inline unsigned long ipipe_test_pipeline_from(struct ipipe_domain *ipd)
+{
+	unsigned long flags, x;
+	ipipe_declare_cpuid;
+
+	ipipe_get_cpu(flags);
+	x = test_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+	ipipe_put_cpu(flags);
+
+	return x;
+}
+
+static inline void ipipe_restore_pipeline_nosync(struct ipipe_domain *ipd,
+						 unsigned long x, int cpuid)
+{
+	/*
+	 * If cpuid is current, then it must be held on entry
+	 * (ipipe_get_cpu/local_irq_save_hw/local_irq_disable_hw).
+	 */
+
+	if (x)
+		__set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+	else
+		__clear_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+}
+
+static inline void ipipe_stall_pipeline_head(void)
+{
+	ipipe_declare_cpuid;
+
+	local_irq_disable_hw();
+	ipipe_load_cpuid();
+	__set_bit(IPIPE_STALL_FLAG, &__ipipe_pipeline_head()->cpudata[cpuid].status);
+}
+
+static inline unsigned long ipipe_test_and_stall_pipeline_head(void)
+{
+	ipipe_declare_cpuid;
+
+	local_irq_disable_hw();
+	ipipe_load_cpuid();
+	return __test_and_set_bit(IPIPE_STALL_FLAG, &__ipipe_pipeline_head()->cpudata[cpuid].status);
+}
+
+void ipipe_unstall_pipeline_head(void);
+
+void fastcall __ipipe_restore_pipeline_head(struct ipipe_domain *head,
+					    unsigned long x);
+
+static inline void ipipe_restore_pipeline_head(unsigned long x)
+{
+	struct ipipe_domain *head = __ipipe_pipeline_head();
+	/* 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, &head->cpudata[ipipe_processor_id()].status)) & 1)
+		__ipipe_restore_pipeline_head(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);
+
+int ipipe_tune_timer(unsigned long ns,
+		     int flags);
+
+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. */
+	ipipe_declare_cpuid;
+	ipipe_load_cpuid();
+	__set_bit(IPIPE_NOSTACK_FLAG, &ipd->cpudata[cpuid].status);
+}
+
+static inline void ipipe_clear_foreign_stack(struct ipipe_domain *ipd)
+{
+	/* Must be called hw interrupts off. */
+	ipipe_declare_cpuid;
+	ipipe_load_cpuid();
+	__clear_bit(IPIPE_NOSTACK_FLAG, &ipd->cpudata[cpuid].status);
+}
+
+#define ipipe_safe_current()					\
+({								\
+	ipipe_declare_cpuid;					\
+	struct task_struct *p;					\
+	ipipe_load_cpuid();					\
+	p = test_bit(IPIPE_NOSTACK_FLAG,			\
+		     &per_cpu(ipipe_percpu_domain, cpuid)->cpudata[cpuid].status) ? &init_task : current; \
+	p; \
+})
+
+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 fastcall 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 fastcall ipipe_set_ptd(int key,
+			   void *value);
+
+void fastcall *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_disable_head()		ipipe_stall_pipeline_head()
+
+#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 ipipe_irq_lock(irq)						\
+	do {								\
+		ipipe_declare_cpuid;					\
+		ipipe_load_cpuid();					\
+		__ipipe_lock_irq(per_cpu(ipipe_percpu_domain, cpuid), cpuid, irq);\
+	} while(0)
+
+#define ipipe_irq_unlock(irq)						\
+	do {								\
+		ipipe_declare_cpuid;					\
+		ipipe_load_cpuid();					\
+		__ipipe_unlock_irq(per_cpu(ipipe_percpu_domain, cpuid), irq);	\
+	} while(0)
+
+#define ipipe_root_domain_p		(ipipe_current_domain == ipipe_root_domain)
+
+#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)
+#define __ipipe_pin_range_globally(start, end) do { } while(0)
+
+#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 local_irq_disable_head()	local_irq_disable()
+
+#endif	/* CONFIG_IPIPE */
+
+#endif	/* !__LINUX_IPIPE_H */
diff --git a/include/linux/ipipe_base.h b/include/linux/ipipe_base.h
new file mode 100644
index 0000000..d0ddf3f
--- /dev/null
+++ b/include/linux/ipipe_base.h
@@ -0,0 +1,88 @@
+/* -*- 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>
+
+/* 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_SYNC_MASK		(1 << IPIPE_SYNC_FLAG)
+
+extern struct ipipe_domain ipipe_root;
+
+#define ipipe_root_domain (&ipipe_root)
+
+#ifdef CONFIG_SMP
+
+void __ipipe_stall_root(void);
+
+unsigned long __ipipe_test_root(void);
+
+unsigned long __ipipe_test_and_stall_root(void);
+
+#else /* !CONFIG_SMP */
+
+/*
+ * Note: This cast relies on cpudata[0].status being the first element in the
+ *       root domain structure (for UP only).
+ */
+#define __ipipe_root_status	(unsigned long *)&ipipe_root
+
+static inline void __ipipe_stall_root(void)
+{
+	set_bit(IPIPE_STALL_FLAG, __ipipe_root_status);
+}
+
+static inline unsigned long __ipipe_test_root(void)
+{
+	return test_bit(IPIPE_STALL_FLAG, __ipipe_root_status);
+}
+
+static inline unsigned long __ipipe_test_and_stall_root(void)
+{
+	return test_and_set_bit(IPIPE_STALL_FLAG, __ipipe_root_status);
+}
+
+#endif /* !CONFIG_SMP */
+
+void __ipipe_unstall_root(void);
+
+void __ipipe_restore_root(unsigned long x);
+
+#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 */
+
+#else /* !CONFIG_IPIPE */
+#define ipipe_check_context(ipd)  do { } while(0)
+#endif	/* CONFIG_IPIPE */
+
+#endif	/* !__LINUX_IPIPE_BASE_H */
diff --git a/include/linux/ipipe_trace.h b/include/linux/ipipe_trace.h
new file mode 100644
index 0000000..c7c6ebd
--- /dev/null
+++ b/include/linux/ipipe_trace.h
@@ -0,0 +1,49 @@
+/* -*- 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
+
+#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);
+
+int ipipe_trace_max_reset(void);
+int ipipe_trace_frozen_reset(void);
+
+#ifdef CONFIG_IPIPE_TRACE_PANIC
+
+void ipipe_trace_panic_freeze(void);
+void ipipe_trace_panic_dump(void);
+
+#else /* !CONFIG_IPIPE_TRACE_PANIC */
+
+static inline void ipipe_trace_panic_freeze(void) { }
+static inline void ipipe_trace_panic_dump(void) { }
+
+#endif /* !CONFIG_IPIPE_TRACE_PANIC */
+
+#endif	/* !__LINUX_IPIPE_H */
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 52fc405..1369b4f 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -146,6 +146,12 @@ struct irq_chip {
  * Pad this out to 32 bytes for cache and indexing reasons.
  */
 struct irq_desc {
+#ifdef CONFIG_IPIPE
+	void			fastcall (*ipipe_ack)(unsigned int irq,
+						      struct irq_desc *desc);
+	void			fastcall (*ipipe_end)(unsigned int irq,
+						      struct irq_desc *desc);
+#endif /* CONFIG_IPIPE */
 	irq_flow_handler_t	handle_irq;
 	struct irq_chip		*chip;
 	void			*handler_data;
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 63fb18d..6c2b3d3 100644
--- a/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 <asm/byteorder.h>
 #include <asm/bug.h>
 
@@ -72,9 +73,12 @@ 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 a/include/linux/linkage.h b/include/linux/linkage.h
index 6c9873f..0b1f634 100644
--- a/include/linux/linkage.h
+++ b/include/linux/linkage.h
@@ -64,4 +64,8 @@
 #define fastcall
 #endif
 
+#ifndef notrace
+#define notrace		__attribute__((no_instrument_function))
+#endif
+
 #endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2d2c08d..bcc8321 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -169,6 +169,7 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_MAPPED_COPY	0x01000000	/* T if mapped copy of data (nommu mmap) */
 #define VM_INSERTPAGE	0x02000000	/* The vma has had "vm_insert_page()" done on it */
 #define VM_ALWAYSDUMP	0x04000000	/* Always include in core dumps */
+#define VM_PINNED	0x08000000	/* Disable faults for the vma */
 
 #ifndef VM_STACK_DEFAULT_FLAGS		/* arch can override this */
 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index d0926d6..991c36c 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -8,6 +8,7 @@
 
 #include <linux/thread_info.h>
 #include <linux/linkage.h>
+#include <linux/ipipe_base.h>
 
 #ifdef CONFIG_DEBUG_PREEMPT
   extern void fastcall add_preempt_count(int val);
@@ -28,18 +29,21 @@ asmlinkage void preempt_schedule(void);
 
 #define preempt_disable() \
 do { \
+	ipipe_check_context(ipipe_root_domain); \
 	inc_preempt_count(); \
 	barrier(); \
 } while (0)
 
 #define preempt_enable_no_resched() \
 do { \
+	ipipe_check_context(ipipe_root_domain); \
 	barrier(); \
 	dec_preempt_count(); \
 } while (0)
 
 #define preempt_check_resched() \
 do { \
+	ipipe_check_context(ipipe_root_domain); \
 	if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
 		preempt_schedule(); \
 } while (0)
@@ -53,10 +57,10 @@ do { \
 
 #else
 
-#define preempt_disable()		do { } while (0)
-#define preempt_enable_no_resched()	do { } while (0)
-#define preempt_enable()		do { } while (0)
-#define preempt_check_resched()		do { } while (0)
+#define preempt_disable()		ipipe_check_context(ipipe_root_domain)
+#define preempt_enable_no_resched()	ipipe_check_context(ipipe_root_domain)
+#define preempt_enable()		ipipe_check_context(ipipe_root_domain)
+#define preempt_check_resched()		ipipe_check_context(ipipe_root_domain)
 
 #endif
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4463735..6c689d9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -54,6 +54,7 @@ struct sched_param {
 #include <linux/cpumask.h>
 #include <linux/errno.h>
 #include <linux/nodemask.h>
+#include <linux/ipipe.h>
 
 #include <asm/system.h>
 #include <asm/semaphore.h>
@@ -151,6 +152,13 @@ extern unsigned long weighted_cpuload(const int cpu);
 /* in tsk->state again */
 #define TASK_NONINTERACTIVE	64
 #define TASK_DEAD		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 */
 
 #define __set_task_state(tsk, state_value)		\
 	do { (tsk)->state = (state_value); } while (0)
@@ -1040,6 +1048,9 @@ struct task_struct {
 
 	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
@@ -1157,6 +1168,11 @@ static inline void put_task_struct(struct task_struct *t)
 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
+#ifdef CONFIG_IPIPE
+#define PF_EVNOTIFY    0x40000000	/* Notify other domains about internal events */
+#else
+#define PF_EVNOTIFY    0
+#endif /* CONFIG_IPIPE */
 
 /*
  * Only the _current_ task can read/write to tsk->flags, but other
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 7ba23ec..e128dcf 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -109,6 +109,8 @@ static inline int smp_call_function_single(int cpuid, void (*func) (void *info),
 
 #endif /* !SMP */
 
+#include <linux/ipipe_base.h>
+
 /*
  * smp_processor_id(): get the current CPU ID.
  *
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 94b767d..57517c3 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -172,7 +172,90 @@ 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)
+#undef TYPE_EQUAL
+#define TYPE_EQUAL(lock, type) \
+	__builtin_types_compatible_p(typeof(lock), type *)
+
+#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_lock_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)
+#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)
@@ -185,7 +268,7 @@ do {								\
 
 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 
-#define spin_lock_irqsave(lock, flags)	flags = _spin_lock_irqsave(lock)
+#define spin_lock_irqsave(lock, flags)	PICK_SPINLOCK_IRQSAVE(lock, flags)
 #define read_lock_irqsave(lock, flags)	flags = _read_lock_irqsave(lock)
 #define write_lock_irqsave(lock, flags)	flags = _write_lock_irqsave(lock)
 
@@ -199,7 +282,7 @@ do {								\
 
 #else
 
-#define spin_lock_irqsave(lock, flags)	_spin_lock_irqsave(lock, flags)
+#define spin_lock_irqsave(lock, flags)	PICK_SPINLOCK_IRQSAVE(lock, flags)
 #define read_lock_irqsave(lock, flags)	_read_lock_irqsave(lock, flags)
 #define write_lock_irqsave(lock, flags)	_write_lock_irqsave(lock, flags)
 #define spin_lock_irqsave_nested(lock, flags, subclass)	\
@@ -207,7 +290,7 @@ 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)
@@ -221,26 +304,25 @@ 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)		__raw_spin_unlock(&(lock)->raw_lock)
+# define spin_unlock(lock)		PICK_SPINOP_RAW(_unlock, lock)
 # define read_unlock(lock)		__raw_read_unlock(&(lock)->raw_lock)
 # define write_unlock(lock)		__raw_write_unlock(&(lock)->raw_lock)
-# define spin_unlock_irq(lock) \
-    do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+# define spin_unlock_irq(lock)	PICK_SPINUNLOCK_IRQ_RAW(lock)
 # define read_unlock_irq(lock) \
     do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
 # define write_unlock_irq(lock) \
     do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
 #endif
 
-#define spin_unlock_irqrestore(lock, flags) \
-					_spin_unlock_irqrestore(lock, flags)
+#define spin_unlock_irqrestore(lock, flags)	\
+					PICK_SPINUNLOCK_IRQRESTORE(lock, flags)
 #define spin_unlock_bh(lock)		_spin_unlock_bh(lock)
 
 #define read_unlock_irqrestore(lock, flags) \
@@ -287,4 +369,25 @@ 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 fastcall __ipipe_spin_lock_irq(raw_spinlock_t *lock);
+void fastcall __ipipe_spin_unlock_irq(raw_spinlock_t *lock);
+unsigned long fastcall __ipipe_spin_lock_irqsave(raw_spinlock_t *lock);
+void fastcall __ipipe_spin_unlock_irqrestore(raw_spinlock_t *lock,
+					     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)
+#endif
+
 #endif /* __LINUX_SPINLOCK_H */
diff --git a/include/linux/spinlock_types.h b/include/linux/spinlock_types.h
index dc5fb69..28dbdc7 100644
--- a/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 {
@@ -86,9 +90,19 @@ typedef struct {
 #endif
 
 #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
+#else
+# define ipipe_spinlock_t	spinlock_t
+# define IPIPE_DEFINE_SPINLOCK(x) DEFINE_SPINLOCK(x)
+#endif
+
 #endif /* __LINUX_SPINLOCK_TYPES_H */
diff --git a/init/Kconfig b/init/Kconfig
index a3f83e2..da44697 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -67,6 +67,7 @@ menu "General setup"
 
 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 a/init/main.c b/init/main.c
index 8b4a7d7..6adddbb 100644
--- a/init/main.c
+++ b/init/main.c
@@ -494,7 +494,7 @@ asmlinkage void __init start_kernel(void)
 	unwind_init();
 	lockdep_init();
 
-	local_irq_disable();
+	local_irq_disable_hw();
 	early_boot_irqs_off();
 	early_init_irq_lock_class();
 
@@ -545,6 +545,11 @@ asmlinkage void __init start_kernel(void)
 	softirq_init();
 	timekeeping_init();
 	time_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");
@@ -691,6 +696,7 @@ static void __init do_basic_setup(void)
 #ifdef CONFIG_SYSCTL
 	sysctl_init();
 #endif
+	ipipe_init_proc();
 
 	do_initcalls();
 }
diff --git a/kernel/Makefile b/kernel/Makefile
index 14f4d45..4c77db5 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
 obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_RELAY) += relay.o
+obj-$(CONFIG_IPIPE) += ipipe/
 obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
diff --git a/kernel/exit.c b/kernel/exit.c
index fec12eb..e9096c9 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -922,6 +922,7 @@ fastcall NORET_TYPE void do_exit(long code)
 
 	if (group_dead)
 		acct_process();
+ 	ipipe_exit_notify(tsk);
 	exit_sem(tsk);
 	__exit_files(tsk);
 	__exit_fs(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index d57118d..d827f37 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -387,6 +387,7 @@ void mmput(struct mm_struct *mm)
 	if (atomic_dec_and_test(&mm->mm_users)) {
 		exit_aio(mm);
 		exit_mmap(mm);
+		ipipe_cleanup_notify(mm);
 		if (!list_empty(&mm->mmlist)) {
 			spin_lock(&mmlist_lock);
 			list_del(&mm->mmlist);
@@ -917,7 +918,7 @@ static inline void copy_flags(unsigned long clone_flags, struct task_struct *p)
 {
 	unsigned long new_flags = p->flags;
 
-	new_flags &= ~(PF_SUPERPRIV | PF_NOFREEZE);
+	new_flags &= ~(PF_SUPERPRIV | PF_NOFREEZE | PF_EVNOTIFY);
 	new_flags |= PF_FORKNOEXEC;
 	if (!(clone_flags & CLONE_PTRACE))
 		p->ptrace = 0;
@@ -1262,6 +1263,14 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	spin_unlock(&current->sighand->siglock);
 	write_unlock_irq(&tasklist_lock);
 	proc_fork_connector(p);
+#ifdef CONFIG_IPIPE
+	{
+	int k;
+
+	for (k = 0; k < IPIPE_ROOT_NPTDKEYS; k++)
+		p->ptd[k] = NULL;
+	}
+#endif /* CONFIG_IPIPE */
 	return p;
 
 bad_fork_cleanup_namespaces:
diff --git a/kernel/ipipe/Kconfig b/kernel/ipipe/Kconfig
new file mode 100644
index 0000000..1f46f07
--- /dev/null
+++ b/kernel/ipipe/Kconfig
@@ -0,0 +1,6 @@
+config IPIPE
+	bool "Interrupt pipeline"
+	default y
+	---help---
+	  Activate this option if you want the interrupt pipeline to be
+	  compiled in.
diff --git a/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 a/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 a/kernel/ipipe/core.c b/kernel/ipipe/core.c
new file mode 100644
index 0000000..4c0d1e8
--- /dev/null
+++ b/kernel/ipipe/core.c
@@ -0,0 +1,1500 @@
+/* -*- 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>
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#endif	/* CONFIG_PROC_FS */
+#include <linux/ipipe_trace.h>
+
+static int __ipipe_ptd_key_count;
+
+static unsigned long __ipipe_ptd_key_map;
+
+struct ipipe_domain ipipe_root =
+	{ .cpudata = {[0 ... IPIPE_NR_CPUS-1] =
+		{ .status = (1<<IPIPE_STALL_FLAG) } } };
+
+DEFINE_PER_CPU(struct ipipe_domain *, ipipe_percpu_domain) =
+	{ &ipipe_root };
+
+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];
+
+/*
+ * ipipe_init() -- Initialization routine of the IPIPE layer. Called
+ * by the host kernel early during the boot procedure.
+ */
+void 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.
+	 */
+
+	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 cpuid, n;
+
+	for (cpuid = 0; cpuid < IPIPE_NR_CPUS; cpuid++) {
+		ipd->cpudata[cpuid].irq_pending_hi = 0;
+
+		for (n = 0; n < IPIPE_IRQ_IWORDS; n++)
+			ipd->cpudata[cpuid].irq_pending_lo[n] = 0;
+
+		for (n = 0; n < IPIPE_NR_IRQS; n++) {
+			ipd->cpudata[cpuid].irq_counters[n].total_hits = 0;
+			ipd->cpudata[cpuid].irq_counters[n].pending_hits = 0;
+		}
+
+		ipd->cpudata[cpuid].evsync = 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 (ipd->cpudata[cpu].irq_pending_hi != 0)
+				cpu_relax();
+		}
+	}
+#endif	/* CONFIG_SMP */
+}
+
+#ifdef CONFIG_SMP
+void __ipipe_stall_root(void)
+{
+	ipipe_declare_cpuid;
+	unsigned long flags;
+
+	ipipe_get_cpu(flags); /* Care for migration. */
+	set_bit(IPIPE_STALL_FLAG, &ipipe_root_domain->cpudata[cpuid].status);
+	ipipe_put_cpu(flags);
+}
+
+unsigned long __ipipe_test_root(void)
+{
+	unsigned long flags, x;
+	ipipe_declare_cpuid;
+
+	ipipe_get_cpu(flags); /* Care for migration. */
+	x = test_bit(IPIPE_STALL_FLAG, &ipipe_root_domain->cpudata[cpuid].status);
+	ipipe_put_cpu(flags);
+
+	return x;
+}
+
+unsigned long __ipipe_test_and_stall_root(void)
+{
+	unsigned long flags, x;
+	ipipe_declare_cpuid;
+
+	ipipe_get_cpu(flags); /* Care for migration. */
+	x = test_and_set_bit(IPIPE_STALL_FLAG,
+			     &ipipe_root_domain->cpudata[cpuid].status);
+	ipipe_put_cpu(flags);
+
+	return x;
+}
+#endif /* CONFIG_SMP */
+
+void __ipipe_unstall_root(void)
+{
+        ipipe_declare_cpuid;
+
+        local_irq_disable_hw();
+
+        ipipe_load_cpuid();
+
+        __clear_bit(IPIPE_STALL_FLAG, &ipipe_root_domain->cpudata[cpuid].status);
+
+        if (unlikely(ipipe_root_domain->cpudata[cpuid].irq_pending_hi != 0))
+                __ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+
+        local_irq_enable_hw();
+}
+
+void __ipipe_restore_root(unsigned long x)
+{
+	if (x)
+		__ipipe_stall_root();
+	else
+		__ipipe_unstall_root();
+}
+
+void fastcall ipipe_stall_pipeline_from(struct ipipe_domain *ipd)
+{
+	ipipe_declare_cpuid;
+#ifdef CONFIG_SMP
+	unsigned long flags;
+
+	ipipe_lock_cpu(flags); /* Care for migration. */
+
+	__set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+
+	if (!__ipipe_pipeline_head_p(ipd))
+		ipipe_unlock_cpu(flags);
+#else	/* CONFIG_SMP */
+	set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+
+	if (__ipipe_pipeline_head_p(ipd))
+		local_irq_disable_hw();
+#endif	/* CONFIG_SMP */
+}
+
+unsigned long fastcall ipipe_test_and_stall_pipeline_from(struct ipipe_domain *ipd)
+{
+	ipipe_declare_cpuid;
+	unsigned long s;
+#ifdef CONFIG_SMP
+	unsigned long flags;
+
+	ipipe_lock_cpu(flags); /* Care for migration. */
+
+	s = __test_and_set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+
+	if (!__ipipe_pipeline_head_p(ipd))
+		ipipe_unlock_cpu(flags);
+#else	/* CONFIG_SMP */
+	s = test_and_set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+
+	if (__ipipe_pipeline_head_p(ipd))
+		local_irq_disable_hw();
+#endif	/* CONFIG_SMP */
+
+	return s;
+}
+
+void fastcall __ipipe_spin_lock_irq(raw_spinlock_t *lock)
+{
+	struct ipipe_domain *ipd;
+	ipipe_declare_cpuid;
+
+	local_irq_disable_hw();
+	__raw_spin_lock(lock);
+	ipipe_load_cpuid();
+	ipd = per_cpu(ipipe_percpu_domain, cpuid);
+	__set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+}
+
+void fastcall __ipipe_spin_unlock_irq(raw_spinlock_t *lock)
+{
+	struct ipipe_domain *ipd;
+	ipipe_declare_cpuid;
+
+	__raw_spin_unlock(lock);
+	ipipe_load_cpuid();
+	ipd = per_cpu(ipipe_percpu_domain, cpuid);
+	__clear_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+	local_irq_enable_hw();
+}
+
+unsigned long fastcall __ipipe_spin_lock_irqsave(raw_spinlock_t *lock)
+{
+	struct ipipe_domain *ipd;
+	ipipe_declare_cpuid;
+	unsigned long flags;
+	int s;
+
+	local_irq_save_hw(flags);
+	__raw_spin_lock(lock);
+	ipipe_load_cpuid();
+	ipd = per_cpu(ipipe_percpu_domain, cpuid);
+	s = __test_and_set_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+
+	return raw_mangle_irq_bits(s, flags);
+}
+
+void fastcall __ipipe_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long x)
+{
+	struct ipipe_domain *ipd;
+	ipipe_declare_cpuid;
+
+	__raw_spin_unlock(lock);
+	ipipe_load_cpuid();
+	ipd = per_cpu(ipipe_percpu_domain, cpuid);
+	if (!raw_demangle_irq_bits(&x))
+		__clear_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+	local_irq_restore_hw(x);
+}
+
+/*
+ * ipipe_unstall_pipeline_from() -- Unstall the pipeline and
+ * synchronize pending interrupts for a given domain. See
+ * __ipipe_walk_pipeline() for more information.
+ */
+void fastcall ipipe_unstall_pipeline_from(struct ipipe_domain *ipd)
+{
+	struct list_head *pos;
+	unsigned long flags;
+	ipipe_declare_cpuid;
+
+	ipipe_lock_cpu(flags);
+
+	__clear_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+
+	if (ipd == per_cpu(ipipe_percpu_domain, cpuid))
+		pos = &ipd->p_link;
+	else
+		pos = __ipipe_pipeline.next;
+
+	__ipipe_walk_pipeline(pos, cpuid);
+
+	if (__ipipe_pipeline_head_p(ipd))
+		local_irq_enable_hw();
+	else
+		ipipe_unlock_cpu(flags);
+}
+
+unsigned long fastcall ipipe_test_and_unstall_pipeline_from(struct ipipe_domain *ipd)
+{
+	unsigned long flags, x;
+	ipipe_declare_cpuid;
+
+	ipipe_get_cpu(flags);
+	x = test_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpuid].status);
+	ipipe_unstall_pipeline_from(ipd);
+	ipipe_put_cpu(flags);
+
+	return x;
+}
+
+void fastcall 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_domain *head;
+	ipipe_declare_cpuid;
+
+	local_irq_disable_hw();
+	ipipe_load_cpuid();
+	head = __ipipe_pipeline_head();
+	__clear_bit(IPIPE_STALL_FLAG, &head->cpudata[cpuid].status);
+
+	if (unlikely(head->cpudata[cpuid].irq_pending_hi != 0)) {
+		if (likely(head == per_cpu(ipipe_percpu_domain, cpuid)))
+			__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+		else
+			__ipipe_walk_pipeline(&head->p_link, cpuid);
+        }
+
+	local_irq_enable_hw();
+}
+
+void fastcall __ipipe_restore_pipeline_head(struct ipipe_domain *head, unsigned long x)
+{
+	ipipe_declare_cpuid;
+
+	local_irq_disable_hw();
+	ipipe_load_cpuid();
+
+	if (x) {
+#ifdef CONFIG_DEBUG_KERNEL
+		static int warned;
+		if (!warned && test_and_set_bit(IPIPE_STALL_FLAG, &head->cpudata[cpuid].status)) {
+			/*
+			 * Already stalled albeit ipipe_restore_pipeline_head()
+			 * should have detected it? Send a warning once.\n");
+			 */
+			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, &head->cpudata[cpuid].status);
+#endif /* CONFIG_DEBUG_KERNEL */
+	}
+	else {
+		__clear_bit(IPIPE_STALL_FLAG, &head->cpudata[cpuid].status);
+		if (unlikely(head->cpudata[cpuid].irq_pending_hi != 0)) {
+			if (likely(head == per_cpu(ipipe_percpu_domain, cpuid)))
+				__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			else
+				__ipipe_walk_pipeline(&head->p_link, cpuid);
+		}
+		local_irq_enable_hw();
+	}
+}
+
+/* __ipipe_walk_pipeline(): Plays interrupts pending in the log. Must
+   be called with local hw interrupts disabled. */
+
+void fastcall __ipipe_walk_pipeline(struct list_head *pos, int cpuid)
+{
+	struct ipipe_domain *this_domain = per_cpu(ipipe_percpu_domain, cpuid);
+
+	while (pos != &__ipipe_pipeline) {
+		struct ipipe_domain *next_domain =
+		    list_entry(pos, struct ipipe_domain, p_link);
+
+		if (test_bit
+		    (IPIPE_STALL_FLAG, &next_domain->cpudata[cpuid].status))
+			break;	/* Stalled stage -- do not go further. */
+
+		if (next_domain->cpudata[cpuid].irq_pending_hi != 0) {
+
+			if (next_domain == this_domain)
+				__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			else {
+				__ipipe_switch_to(this_domain, next_domain,
+						  cpuid);
+
+				ipipe_load_cpuid();	/* Processor might have changed. */
+
+				if (this_domain->cpudata[cpuid].
+				    irq_pending_hi != 0
+				    && !test_bit(IPIPE_STALL_FLAG,
+						 &this_domain->cpudata[cpuid].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 list_head *ln;
+	unsigned long flags;
+	ipipe_declare_cpuid;
+
+	ipipe_lock_cpu(flags);
+
+	this_domain = next_domain = per_cpu(ipipe_percpu_domain, cpuid);
+
+	__clear_bit(IPIPE_STALL_FLAG, &this_domain->cpudata[cpuid].status);
+
+	if (this_domain->cpudata[cpuid].irq_pending_hi != 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);
+
+		if (test_bit(IPIPE_STALL_FLAG,
+			     &next_domain->cpudata[cpuid].status))
+			break;
+
+		if (next_domain->cpudata[cpuid].irq_pending_hi == 0)
+			continue;
+
+		per_cpu(ipipe_percpu_domain, cpuid) = next_domain;
+
+sync_stage:
+		__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+
+		ipipe_load_cpuid();	/* Processor might have changed. */
+
+		if (per_cpu(ipipe_percpu_domain, cpuid) != next_domain)
+			/*
+			 * Something has changed the current domain under our
+			 * feet, recycling the register set; take note.
+			 */
+			this_domain = per_cpu(ipipe_percpu_domain, cpuid);
+	}
+
+	per_cpu(ipipe_percpu_domain, cpuid) = this_domain;
+
+	ipipe_unlock_cpu(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(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 fastcall __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;
+	ipipe_declare_cpuid;
+	int propagate = 1;
+
+	ipipe_lock_cpu(flags);
+
+	start_domain = this_domain = per_cpu(ipipe_percpu_domain, cpuid);
+
+	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) {
+			per_cpu(ipipe_percpu_domain, cpuid) = next_domain;
+			next_domain->cpudata[cpuid].evsync |= (1LL << event);
+			ipipe_unlock_cpu(flags);
+			propagate = !evhand(event,start_domain,data);
+			ipipe_lock_cpu(flags);
+			next_domain->cpudata[cpuid].evsync &= ~(1LL << event);
+			if (per_cpu(ipipe_percpu_domain, cpuid) != next_domain)
+				this_domain = per_cpu(ipipe_percpu_domain, cpuid);
+		}
+
+		if (next_domain != ipipe_root_domain &&	/* NEVER sync the root stage here. */
+		    next_domain->cpudata[cpuid].irq_pending_hi != 0 &&
+		    !test_bit(IPIPE_STALL_FLAG,&next_domain->cpudata[cpuid].status)) {
+			per_cpu(ipipe_percpu_domain, cpuid) = next_domain;
+			__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+			ipipe_load_cpuid();
+			if (per_cpu(ipipe_percpu_domain, cpuid) != next_domain)
+				this_domain = per_cpu(ipipe_percpu_domain, cpuid);
+		}
+
+		per_cpu(ipipe_percpu_domain, cpuid) = this_domain;
+
+		if (next_domain == this_domain || !propagate)
+			break;
+	}
+
+	ipipe_unlock_cpu(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), and in any case, must not rely on handlers
+ * provided by lower priority domains during the acknowledge cycle
+ * (see __ipipe_handle_irq).
+ *
+ * Called with hw interrupts off.
+ */
+
+int fastcall __ipipe_dispatch_wired(struct ipipe_domain *head, unsigned irq)
+{
+	struct ipcpudata *cpudata;
+	struct ipipe_domain *old;
+	ipipe_declare_cpuid;
+
+	ipipe_load_cpuid();
+	cpudata = &head->cpudata[cpuid];
+	cpudata->irq_counters[irq].total_hits++;
+
+	if (test_bit(IPIPE_LOCK_FLAG, &head->irqs[irq].control)) {
+		/* If we can't process this IRQ right now, we must
+		 * mark it as pending, so that it will get played
+		 * during normal log sync when the corresponding
+		 * interrupt source is eventually unlocked. */
+		cpudata->irq_counters[irq].pending_hits++;
+		return 0;
+	}
+
+	if (test_bit(IPIPE_STALL_FLAG, &cpudata->status)) {
+		cpudata->irq_counters[irq].pending_hits++;
+		__ipipe_set_irq_bit(head, cpuid, irq);
+		return 0;
+	}
+
+	old = per_cpu(ipipe_percpu_domain, cpuid);
+	per_cpu(ipipe_percpu_domain, cpuid) = head; /* Switch to the head domain. */
+
+	__set_bit(IPIPE_STALL_FLAG, &cpudata->status);
+	head->irqs[irq].handler(irq,head->irqs[irq].cookie); /* Call the ISR. */
+	__ipipe_run_irqtail();
+	__clear_bit(IPIPE_STALL_FLAG, &cpudata->status);
+
+	/* We expect the caller to start a complete pipeline walk upon
+	 * return, so that propagated interrupts will get played. */
+
+	if (per_cpu(ipipe_percpu_domain, cpuid) == head)
+		per_cpu(ipipe_percpu_domain, cpuid) = old; /* Back to the preempted domain. */
+
+	return 1;
+}
+
+/*
+ * __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 fastcall __ipipe_sync_stage(unsigned long syncmask)
+{
+	unsigned long mask, submask;
+	struct ipcpudata *cpudata;
+	struct ipipe_domain *ipd;
+	ipipe_declare_cpuid;
+	int level, rank;
+	unsigned irq;
+
+	ipipe_load_cpuid();
+	ipd = per_cpu(ipipe_percpu_domain, cpuid);
+	cpudata = &ipd->cpudata[cpuid];
+
+	if (__test_and_set_bit(IPIPE_SYNC_FLAG, &cpudata->status))
+		return;
+
+	/*
+	 * 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 = (cpudata->irq_pending_hi & syncmask)) != 0) {
+		level = __ipipe_ffnz(mask);
+
+		while ((submask = cpudata->irq_pending_lo[level]) != 0) {
+			rank = __ipipe_ffnz(submask);
+			irq = (level << IPIPE_IRQ_ISHIFT) + rank;
+
+			if (test_bit(IPIPE_LOCK_FLAG, &ipd->irqs[irq].control)) {
+				__clear_bit(rank, &cpudata->irq_pending_lo[level]);
+				continue;
+			}
+
+			if (--cpudata->irq_counters[irq].pending_hits == 0) {
+				__clear_bit(rank, &cpudata->irq_pending_lo[level]);
+				if (cpudata->irq_pending_lo[level] == 0)
+					__clear_bit(level, &cpudata->irq_pending_hi);
+			}
+
+			__set_bit(IPIPE_STALL_FLAG, &cpudata->status);
+
+			if (ipd == ipipe_root_domain)
+				trace_hardirqs_off();
+
+			__ipipe_run_isr(ipd, irq, cpuid);
+#ifdef CONFIG_SMP
+			{
+				int _cpuid = ipipe_processor_id();
+
+				if (_cpuid != cpuid) {	/* 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.
+					 */
+					cpuid = _cpuid;
+					cpudata = &ipd->cpudata[cpuid];
+					__set_bit(IPIPE_SYNC_FLAG, &cpudata->status);
+				}
+			}
+#endif	/* CONFIG_SMP */
+			if (ipd == ipipe_root_domain &&
+			    test_bit(IPIPE_STALL_FLAG, &cpudata->status))
+				trace_hardirqs_on();
+
+			__clear_bit(IPIPE_STALL_FLAG, &cpudata->status);
+		}
+	}
+
+	__clear_bit(IPIPE_SYNC_FLAG, &cpudata->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 list_head *pos;
+	unsigned long flags;
+
+	if (ipipe_current_domain != ipipe_root_domain) {
+		printk(KERN_WARNING
+		       "I-pipe: Only the root domain may register a new domain.\n");
+		return -EPERM;
+	}
+
+	if (attr->priority == IPIPE_HEAD_PRIORITY &&
+	    test_bit(IPIPE_AHEAD_FLAG,&__ipipe_pipeline_head()->flags))
+		return -EAGAIN;	/* Cannot override current head. */
+
+	flags = ipipe_critical_enter(NULL);
+
+	list_for_each(pos, &__ipipe_pipeline) {
+		struct ipipe_domain *_ipd =
+			list_entry(pos, struct ipipe_domain, p_link);
+		if (_ipd->domid == attr->domid)
+			break;
+	}
+
+	ipipe_critical_exit(flags);
+
+	if (pos != &__ipipe_pipeline)
+		/* A domain with the given id already exists -- fail. */
+		return -EBUSY;
+
+	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) {
+		struct ipipe_domain *_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_WARNING "I-pipe: Domain %s registered.\n", ipd->name);
+
+	/*
+	 * Finally, allow the new domain to perform its initialization
+	 * chores.
+	 */
+
+	if (attr->entry != NULL) {
+		ipipe_declare_cpuid;
+
+		ipipe_lock_cpu(flags);
+
+		per_cpu(ipipe_percpu_domain, cpuid) = ipd;
+		attr->entry();
+		per_cpu(ipipe_percpu_domain, cpuid) = ipipe_root_domain;
+
+		ipipe_load_cpuid();	/* Processor might have changed. */
+
+		if (ipipe_root_domain->cpudata[cpuid].irq_pending_hi != 0 &&
+		    !test_bit(IPIPE_STALL_FLAG,
+			      &ipipe_root_domain->cpudata[cpuid].status))
+			__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
+
+		ipipe_unlock_cpu(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_current_domain != ipipe_root_domain) {
+		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
+	{
+		int nr_cpus = num_online_cpus(), _cpuid;
+		unsigned irq;
+
+		/*
+		 * 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 (_cpuid = 0; _cpuid < nr_cpus; _cpuid++)
+			for (irq = 0; irq < IPIPE_NR_IRQS; irq++)
+				while (ipd->cpudata[_cpuid].irq_counters[irq].pending_hits > 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_WARNING "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.
+ */
+int fastcall __ipipe_schedule_irq(unsigned irq, struct list_head *head)
+{
+	struct list_head *ln;
+	unsigned long flags;
+	ipipe_declare_cpuid;
+
+	if (irq >= IPIPE_NR_IRQS ||
+	    (ipipe_virtual_irq_p(irq)
+	     && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)))
+		return -EINVAL;
+
+	ipipe_lock_cpu(flags);
+
+	ln = head;
+
+	while (ln != &__ipipe_pipeline) {
+		struct ipipe_domain *ipd =
+			list_entry(ln, struct ipipe_domain, p_link);
+
+		if (test_bit(IPIPE_HANDLE_FLAG, &ipd->irqs[irq].control)) {
+			ipd->cpudata[cpuid].irq_counters[irq].total_hits++;
+			ipd->cpudata[cpuid].irq_counters[irq].pending_hits++;
+			__ipipe_set_irq_bit(ipd, cpuid, irq);
+			ipipe_unlock_cpu(flags);
+			return 1;
+		}
+
+		ln = ipd->p_link.next;
+	}
+
+	ipipe_unlock_cpu(flags);
+
+	return 0;
+}
+
+/* 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, cpuid;
+
+	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.
+		 */
+
+		for_each_online_cpu(cpuid) {
+			while (ipd->cpudata[cpuid].evsync & (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 fastcall 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 fastcall ipipe_set_ptd (int key, void *value)
+
+{
+	if (key < 0 || key >= IPIPE_ROOT_NPTDKEYS)
+		return -EINVAL;
+
+	current->ptd[key] = value;
+
+	return 0;
+}
+
+void fastcall *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
+void ipipe_check_context(struct ipipe_domain *border_ipd)
+{
+	static int check_hit;
+
+	if (likely(ipipe_current_domain->priority <= border_ipd->priority) ||
+	    check_hit)
+		return;
+
+	check_hit = 1;
+
+	ipipe_trace_panic_freeze();
+	ipipe_set_printk_sync(ipipe_current_domain);
+	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);
+	show_stack(NULL, NULL);
+	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_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);
+#ifdef CONFIG_SMP
+EXPORT_SYMBOL(__ipipe_stall_root);
+EXPORT_SYMBOL(__ipipe_test_root);
+EXPORT_SYMBOL(__ipipe_test_and_stall_root);
+#endif /* CONFIG_SMP */
+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_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_schedule_irq);
diff --git a/kernel/ipipe/tracer.c b/kernel/ipipe/tracer.c
new file mode 100644
index 0000000..de08cb1
--- /dev/null
+++ b/kernel/ipipe/tracer.c
@@ -0,0 +1,1291 @@
+/* -*- linux-c -*-
+ * kernel/ipipe/tracer.c
+ *
+ * Copyright (C) 2005 Luotao Fu.
+ *               2005, 2006 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/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    30
+
+#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,
+};
+
+#define IPIPE_TYPE_MASK             0x0007
+#define IPIPE_TYPE_BITS             3
+
+
+#ifdef CONFIG_IPIPE_TRACE_VMALLOC
+
+static struct ipipe_trace_path *trace_paths[NR_CPUS];
+
+#else /* !CONFIG_IPIPE_TRACE_VMALLOC */
+
+static struct ipipe_trace_path trace_paths[NR_CPUS][IPIPE_TRACE_PATHS] =
+	{ [0 ... NR_CPUS-1] =
+		{ [0 ... IPIPE_TRACE_PATHS-1] =
+			{ .begin = -1, .end = -1 }
+		}
+	};
+#endif /* CONFIG_IPIPE_TRACE_VMALLOC */
+
+int ipipe_trace_enable = 0;
+
+static int active_path[NR_CPUS] =
+	{ [0 ... NR_CPUS-1] = IPIPE_DEFAULT_ACTIVE };
+static int max_path[NR_CPUS] =
+	{ [0 ... NR_CPUS-1] = IPIPE_DEFAULT_MAX };
+static int frozen_path[NR_CPUS] =
+	{ [0 ... NR_CPUS-1] = 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;
+static unsigned long trace_overhead;
+
+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, int cpu_id)
+{
+	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);
+
+		if (test_bit(IPIPE_STALL_FLAG, &ipd->cpudata[cpu_id].status))
+			point->flags |= 1 << (i + IPIPE_TFLG_DOMSTATE_SHIFT);
+
+		if (ipd == per_cpu(ipipe_percpu_domain, cpu_id))
+			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_id)
+{
+	int new_active = old;
+	struct ipipe_trace_path *tp;
+
+	do {
+		if (++new_active == IPIPE_TRACE_PATHS)
+			new_active = 0;
+		tp = &trace_paths[cpu_id][new_active];
+	} while ((new_active == max_path[cpu_id]) ||
+	         (new_active == frozen_path[cpu_id]) ||
+	         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_id, struct ipipe_trace_path *tp, int pos)
+{
+	struct ipipe_trace_path *old_tp = tp;
+	long active = active_path[cpu_id];
+	unsigned long long length;
+
+	/* do we have a new worst case? */
+	length = tp->point[tp->end].timestamp -
+	         tp->point[tp->begin].timestamp;
+	if (length > (trace_paths[cpu_id][max_path[cpu_id]]).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;
+		max_path[cpu_id] = active;
+
+		/* find next unused trace path */
+		active = __ipipe_get_free_trace_path(active, cpu_id);
+
+		spin_unlock(&global_path_lock);
+
+		tp = &trace_paths[cpu_id][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_id, struct ipipe_trace_path *tp, int pos)
+{
+	struct ipipe_trace_path *old_tp = tp;
+	long active = active_path[cpu_id];
+	int i;
+
+	/* 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);
+
+	frozen_path[cpu_id] = active;
+
+	/* find next unused trace path */
+	active = __ipipe_get_free_trace_path(active, cpu_id);
+
+	/* check if this is the first frozen path */
+	for_each_online_cpu(i) {
+		if ((i != cpu_id) &&
+		    (trace_paths[i][frozen_path[i]].end >= 0))
+			tp->end = -1;
+	}
+
+	spin_unlock(&global_path_lock);
+
+	tp = &trace_paths[cpu_id][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_id;
+
+	local_irq_save_hw_notrace(flags);
+
+	cpu_id = ipipe_processor_id();
+ restart:
+	tp = old_tp = &trace_paths[cpu_id][active_path[cpu_id]];
+
+	/* 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 != &trace_paths[cpu_id][active_path[cpu_id]])) {
+		/* 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, cpu_id);
+
+	/* 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) &&
+	    (trace_paths[cpu_id][frozen_path[cpu_id]].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_id, tp, pos);
+		else
+			tp = __ipipe_trace_end(cpu_id, 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 */
+		active_path[cpu_id] = tp - trace_paths[cpu_id];
+	}
+
+	/* 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_id;
+	struct ipipe_trace_path *tp;
+
+	spin_lock_irqsave(&global_path_lock, flags);
+
+	cpu_id = ipipe_processor_id();
+ restart:
+	tp = &trace_paths[cpu_id][active_path[cpu_id]];
+
+	/* 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 != &trace_paths[cpu_id][active_path[cpu_id]]) {
+		/* 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_id;
+	struct ipipe_trace_path *tp;
+
+	/* release spinlock first - it's not involved in the NMI issue */
+	spin_unlock(&global_path_lock);
+
+	cpu_id = ipipe_processor_id();
+	tp = &trace_paths[cpu_id][active_path[cpu_id]];
+
+	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);
+
+	local_irq_restore_hw(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);
+
+int ipipe_trace_max_reset(void)
+{
+	int cpu_id;
+	unsigned long flags;
+	struct ipipe_trace_path *path;
+	int ret = 0;
+
+	flags = __ipipe_global_path_lock();
+
+	for_each_online_cpu(cpu_id) {
+		path = &trace_paths[cpu_id][max_path[cpu_id]];
+
+		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_id;
+	unsigned long flags;
+	struct ipipe_trace_path *path;
+	int ret = 0;
+
+	flags = __ipipe_global_path_lock();
+
+	for_each_online_cpu(cpu_id) {
+		path = &trace_paths[cpu_id][frozen_path[cpu_id]];
+
+		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((pid_t)point->v);
+
+	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);
+}
+
+#ifdef CONFIG_IPIPE_TRACE_PANIC
+void ipipe_trace_panic_freeze(void)
+{
+	unsigned long flags;
+	int cpu_id;
+
+	if (!ipipe_trace_enable)
+		return;
+
+	ipipe_trace_enable = 0;
+	local_irq_save_hw_notrace(flags);
+
+	cpu_id = ipipe_processor_id();
+
+	panic_path = &trace_paths[cpu_id][active_path[cpu_id]];
+
+	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 task_info[12];
+
+	if (!panic_path)
+		return;
+
+	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 buf[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(buf);
+
+			switch (point->type & IPIPE_TYPE_MASK) {
+				case IPIPE_TRACE_FUNC:
+					printk("           ");
+					break;
+
+				case IPIPE_TRACE_PID:
+					__ipipe_get_task_info(task_info,
+							      point, 1);
+					printk(task_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;
+	}
+}
+
+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);
+	}
+}
+
+#if defined(CONFIG_XENO_OPT_DEBUG) || defined(CONFIG_DEBUG_PREEMPT)
+static void __ipipe_print_dbgwarning(struct seq_file *m)
+{
+	seq_puts(m, "\n******** WARNING ********\n"
+		"The following debugging options will increase the observed "
+		"latencies:\n"
+#ifdef CONFIG_XENO_OPT_DEBUG
+		" o CONFIG_XENO_OPT_DEBUG\n"
+#endif /* CONFIG_XENO_OPT_DEBUG */
+#ifdef CONFIG_XENO_OPT_DEBUG_QUEUES
+		" o CONFIG_XENO_OPT_DEBUG_QUEUES (very costly)\n"
+#endif /* CONFIG_XENO_OPT_DEBUG */
+#ifdef CONFIG_DEBUG_PREEMPT
+		" o CONFIG_DEBUG_PREEMPT\n"
+#endif /* CONFIG_DEBUG_PREEMPT */
+		"\n");
+}
+#else /* !WARN_ON_DEBUGGING_LATENCIES */
+# define __ipipe_print_dbgwarning(m)
+#endif /* WARN_ON_DEBUGGING_LATENCIES */
+
+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 *path;
+		unsigned long length_usecs;
+		int points, i;
+		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(i) {
+			path = &trace_paths[i][max_path[i]];
+			if ((print_path == NULL) ||
+			    (path->length > print_path->length))
+				print_path = path;
+		}
+		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);
+		__ipipe_print_dbgwarning(m);
+		seq_printf(m, "Begin: %lld cycles, Trace Points: %d (-%d/+%d), "
+			"Length: %lu us\n",
+			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;
+
+			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 *path;
+		int i;
+		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(i) {
+			path = &trace_paths[i][frozen_path[i]];
+			if (path->end >= 0)
+				print_path = path;
+		}
+		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);
+		__ipipe_print_dbgwarning(m);
+		seq_printf(m, "Freeze: %lld cycles, Trace Points: %d (+%d)\n",
+			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;
+}
+
+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) {
+		trace_paths[cpu] = vmalloc(
+			sizeof(struct ipipe_trace_path) * IPIPE_TRACE_PATHS);
+		if (!trace_paths) {
+			printk(KERN_ERR "I-pipe: "
+			       "insufficient memory for trace buffer.\n");
+			return;
+		}
+		memset(trace_paths[cpu], 0,
+			sizeof(struct ipipe_trace_path) * IPIPE_TRACE_PATHS);
+		for (path = 0; path < IPIPE_TRACE_PATHS; path++) {
+			trace_paths[cpu][path].begin = -1;
+			trace_paths[cpu][path].end   = -1;
+		}
+	}
+#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;
+
+	__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 a/kernel/irq/chip.c b/kernel/irq/chip.c
index d27b258..fa7e006 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -308,7 +308,9 @@ 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;
@@ -386,8 +388,13 @@ 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);
+#endif
 out:
+#ifndef CONFIG_IPIPE
 	desc->chip->eoi(irq);
+#endif
 
 	spin_unlock(&desc->lock);
 }
@@ -431,8 +438,10 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 
 	kstat_cpu(cpu).irqs[irq]++;
 
+#ifndef CONFIG_IPIPE
 	/* Start handling the irq */
 	desc->chip->ack(irq);
+#endif /* CONFIG_IPIPE */
 
 	/* Mark the IRQ currently in progress.*/
 	desc->status |= IRQ_INPROGRESS;
@@ -472,6 +481,70 @@ out_unlock:
 	spin_unlock(&desc->lock);
 }
 
+#ifdef CONFIG_IPIPE
+
+void fastcall __ipipe_ack_simple_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void fastcall __ipipe_end_simple_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void fastcall __ipipe_ack_level_irq(unsigned irq, struct irq_desc *desc)
+{
+	mask_ack_irq(desc, irq);
+}
+
+void fastcall __ipipe_end_level_irq(unsigned irq, struct irq_desc *desc)
+{
+	if (desc->chip->unmask)
+		desc->chip->unmask(irq);
+}
+
+void fastcall __ipipe_ack_fasteoi_irq(unsigned irq, struct irq_desc *desc)
+{
+	desc->chip->mask(irq);
+	desc->chip->eoi(irq);
+}
+
+void fastcall __ipipe_end_fasteoi_irq(unsigned irq, struct irq_desc *desc)
+{
+	desc->chip->unmask(irq);
+}
+
+void fastcall __ipipe_ack_edge_irq(unsigned irq, struct irq_desc *desc)
+{
+	desc->chip->ack(irq);
+}
+
+void fastcall __ipipe_end_edge_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void fastcall __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 fastcall __ipipe_noack_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+void fastcall __ipipe_noend_irq(unsigned irq, struct irq_desc *desc)
+{
+}
+
+#endif /* CONFIG_IPIPE */
+
 #ifdef CONFIG_SMP
 /**
  *	handle_percpu_IRQ - Per CPU local irq handler
@@ -487,8 +560,10 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 
 	kstat_this_cpu.irqs[irq]++;
 
+#ifndef CONFIG_IPIPE
 	if (desc->chip->ack)
 		desc->chip->ack(irq);
+#endif /* CONFIG_IPIPE */
 
 	action_ret = handle_IRQ_event(irq, desc->action);
 	if (!noirqdebug)
@@ -498,6 +573,22 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 		desc->chip->eoi(irq);
 }
 
+#ifdef CONFIG_IPIPE
+
+void fastcall __ipipe_ack_percpu_irq(unsigned irq, struct irq_desc *desc)
+{
+	if (desc->chip->ack)
+		desc->chip->ack(irq);
+}
+
+void fastcall __ipipe_end_percpu_irq(unsigned irq, struct irq_desc *desc)
+{
+	if (desc->chip->eoi)
+		desc->chip->eoi(irq);
+}
+
+#endif /* CONFIG_IPIPE */
+
 #endif /* CONFIG_SMP */
 
 void
@@ -517,6 +608,30 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 
 	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);
@@ -528,7 +643,17 @@ __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 */
 	}
+#ifdef CONFIG_IPIPE
+ 	else {
+ 		desc->ipipe_ack = &__ipipe_ack_bad_irq;
+ 		desc->ipipe_end = &__ipipe_noend_irq;
+ 	}
+#endif /* CONFIG_IPIPE */
 
 	spin_lock_irqsave(&desc->lock, flags);
 
@@ -540,6 +665,10 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 		}
 		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;
diff --git a/kernel/printk.c b/kernel/printk.c
index c770e1a..a50b8ea 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -479,6 +479,41 @@ 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
@@ -501,6 +536,43 @@ static int have_callable_console(void)
 
 asmlinkage int printk(const char *fmt, ...)
 {
+	int r, fbytes, oldcount;
+    	unsigned long flags;
+	va_list args;
+
+	va_start(args, fmt);
+
+	if (ipipe_current_domain == ipipe_root_domain ||
+	    test_bit(IPIPE_SPRINTK_FLAG,&ipipe_current_domain->flags) ||
+	    oops_in_progress) {
+		r = vprintk(fmt, args);
+		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;
 
@@ -510,6 +582,7 @@ 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 a/kernel/sched.c b/kernel/sched.c
index cca93cc..26f9c28 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1409,7 +1409,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 
 	rq = task_rq_lock(p, &flags);
 	old_state = p->state;
-	if (!(old_state & state))
+	if (!(old_state & state) || (old_state & TASK_NOWAKEUP))
 		goto out;
 
 	if (p->array)
@@ -1830,6 +1830,8 @@ asmlinkage void schedule_tail(struct task_struct *prev)
 #endif
 	if (current->set_child_tid)
 		put_user(current->pid, current->set_child_tid);
+
+	ipipe_init_notify(current);
 }
 
 /*
@@ -3420,12 +3422,15 @@ asmlinkage void __sched schedule(void)
 	long *switch_count;
 	struct rq *rq;
 
+	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.
 	 * Otherwise, whine if we are scheduling when we should not be.
 	 */
-	if (unlikely(in_atomic() && !current->exit_state)) {
+	if (unlikely(!(current->state & TASK_ATOMICSWITCH) && in_atomic() &&
+			!current->exit_state)) {
 		printk(KERN_ERR "BUG: scheduling while atomic: "
 			"%s/0x%08x/%d\n",
 			current->comm, preempt_count(), current->pid);
@@ -3436,8 +3441,13 @@ asmlinkage void __sched schedule(void)
 	}
 	profile_hit(SCHED_PROFILING, __builtin_return_address(0));
 
+	if (unlikely(current->state & TASK_ATOMICSWITCH)) {
+		current->state &= ~TASK_ATOMICSWITCH;
+		goto need_resched_nodisable;
+	}
 need_resched:
 	preempt_disable();
+need_resched_nodisable:
 	prev = current;
 	release_kernel_lock(prev);
 need_resched_nonpreemptible:
@@ -3555,6 +3565,8 @@ switch_tasks:
 		prepare_task_switch(rq, next);
 		prev = context_switch(rq, prev, next);
 		barrier();
+ 		if (task_hijacked(prev))
+ 		    return;
 		/*
 		 * this_rq must be evaluated again because prev may have moved
 		 * CPUs since it called schedule(), thus the 'rq' on its stack
@@ -3568,7 +3580,7 @@ switch_tasks:
 	if (unlikely(reacquire_kernel_lock(prev) < 0))
 		goto need_resched_nonpreemptible;
 	preempt_enable_no_resched();
-	if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
+	if (unlikely(test_thread_flag(TIF_NEED_RESCHED) && ipipe_root_domain_p))
 		goto need_resched;
 }
 EXPORT_SYMBOL(schedule);
@@ -3586,6 +3598,7 @@ asmlinkage void __sched preempt_schedule(void)
 	struct task_struct *task = current;
 	int saved_lock_depth;
 #endif
+	ipipe_check_context(ipipe_root_domain);
 	/*
 	 * If there is a non-zero preempt_count or interrupts are disabled,
 	 * we do not want to preempt the current task.  Just return..
@@ -4284,6 +4297,7 @@ recheck:
 		deactivate_task(p, rq);
 	oldprio = p->prio;
 	__setscheduler(p, policy, param->sched_priority);
+	ipipe_setsched_notify(p);
 	if (array) {
 		__activate_task(p, rq);
 		/*
@@ -7057,3 +7071,50 @@ void set_curr_task(int cpu, struct task_struct *p)
 }
 
 #endif
+
+#ifdef CONFIG_IPIPE
+
+int ipipe_setscheduler_root (struct task_struct *p, int policy, int prio)
+{
+	struct prio_array *array;
+	unsigned long flags;
+	struct rq *rq;
+	int oldprio;
+
+	rq = task_rq_lock(p, &flags);
+	array = p->array;
+	if (array)
+		deactivate_task(p, rq);
+	oldprio = p->prio;
+	__setscheduler(p, policy, prio);
+	if (array) {
+		__activate_task(p, rq);
+		if (task_running(rq, p)) {
+			if (p->prio > oldprio)
+				resched_task(rq->curr);
+		} else if (TASK_PREEMPTS_CURR(p, rq))
+			resched_task(rq->curr);
+	}
+	task_rq_unlock(rq, &flags);
+
+	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);
+	if (reacquire_kernel_lock(current) < 0)
+		;
+	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 a/kernel/signal.c b/kernel/signal.c
index 5630255..d577f31 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -508,6 +508,7 @@ 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 case.
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 2c6c2bf..14fda25 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -88,7 +88,7 @@ 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_PROVE_LOCKING
+#if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_IPIPE)
 	_raw_spin_lock(lock);
 #else
 	_raw_spin_lock_flags(lock, &flags);
@@ -305,7 +305,7 @@ 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_PROVE_SPIN_LOCKING
+#if defined(CONFIG_PROVE_SPIN_LOCKING) || defined(CONFIG_IPIPE)
 	_raw_spin_lock(lock);
 #else
 	_raw_spin_lock_flags(lock, &flags);
diff --git a/kernel/sys.c b/kernel/sys.c
index 6e2101d..70dd5f2 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -227,9 +227,11 @@ int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh,
 {
 	int ret;
 
-	rcu_read_lock();
+	if (ipipe_root_domain_p)
+		rcu_read_lock();
 	ret = notifier_call_chain(&nh->head, val, v);
-	rcu_read_unlock();
+	if (ipipe_root_domain_p)
+		rcu_read_unlock();
 	return ret;
 }
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 5c26818..36cd9ec 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -71,6 +71,8 @@ config HEADERS_CHECK
 	  exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
 	  your build tree), to make sure they're suitable.
 
+source "kernel/ipipe/Kconfig.debug"
+
 config DEBUG_KERNEL
 	bool "Kernel debugging"
 	help
diff --git a/lib/bust_spinlocks.c b/lib/bust_spinlocks.c
index a2055bc..a49201f 100644
--- a/lib/bust_spinlocks.c
+++ b/lib/bust_spinlocks.c
@@ -12,14 +12,19 @@
 #include <linux/tty.h>
 #include <linux/wait.h>
 #include <linux/vt_kern.h>
+#include <linux/ipipe_trace.h>
 
 
 void bust_spinlocks(int yes)
 {
 	if (yes) {
+		ipipe_trace_panic_freeze();
 		oops_in_progress = 1;
 	} else {
 		int loglevel_save = console_loglevel;
+
+		ipipe_trace_panic_dump();
+
 #ifdef CONFIG_VT
 		unblank_screen();
 #endif
diff --git a/lib/ioremap.c b/lib/ioremap.c
index a9e4415..52d1787 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -84,8 +84,8 @@ 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 a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index eddc9b3..7078cd0 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -13,6 +13,9 @@ unsigned int debug_smp_processor_id(void)
 	int this_cpu = raw_smp_processor_id();
 	cpumask_t this_mask;
 
+	if (!ipipe_root_domain_p)
+		goto out;
+
 	if (likely(preempt_count))
 		goto out;
 
diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c
index 479fd46..5e135ef 100644
--- a/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 a/mm/memory.c b/mm/memory.c
index ef09f0a..bb4cff1 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -50,6 +50,7 @@
 #include <linux/delayacct.h>
 #include <linux/init.h>
 #include <linux/writeback.h>
+#include <linux/vmalloc.h>
 
 #include <asm/pgalloc.h>
 #include <asm/uaccess.h>
@@ -418,13 +419,41 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_
 	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);
+		return;
+		
+	}
+	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
  * covered by this vma.
  */
 
-static inline void
+static inline int
 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)
@@ -466,6 +495,25 @@ 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 (((vm_flags|src_mm->def_flags) & (VM_LOCKED|VM_PINNED)) == (VM_LOCKED|VM_PINNED)) {
+			struct page *old_page = vm_normal_page(vma, addr, pte);
+			page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
+			if (!page)
+				return -ENOMEM;
+
+			cow_user_page(page, old_page, addr, vma);
+			pte = mk_pte(page, vma->vm_page_prot);
+			
+			if (vm_flags & VM_SHARED)
+				pte = pte_mkclean(pte);
+			pte = pte_mkold(pte);
+
+			page_dup_rmap(page);
+			rss[!!PageAnon(page)]++;
+			goto out_set_pte;
+		}
+#endif /* CONFIG_IPIPE */
 		ptep_set_wrprotect(src_mm, addr, src_pte);
 		pte = pte_wrprotect(pte);
 	}
@@ -487,6 +535,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 
 out_set_pte:
 	set_pte_at(dst_mm, addr, dst_pte, pte);
+	return 0;
 }
 
 static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
@@ -524,7 +573,9 @@ again:
 			progress++;
 			continue;
 		}
-		copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss);
+		if (copy_one_pte(dst_mm, src_mm, dst_pte,
+				 src_pte, vma, addr, rss))
+			return -ENOMEM;
 		progress += 8;
 	} while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
 
@@ -1170,7 +1221,7 @@ static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd,
 		if (err)
 			break;
 	} while (pud++, addr = next, addr != end);
-	return err;
+	return 0;
 }
 
 int zeromap_page_range(struct vm_area_struct *vma,
@@ -1441,34 +1492,6 @@ 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);
-		return;
-
-	}
-	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
@@ -2692,3 +2715,117 @@ int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, in
 
 	return buf - old_buf;
 }
+
+#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_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 (ipipe_pin_pte_range(mm, pmd, vma, addr, end))
+			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 (ipipe_pin_pmd_range(mm, pud, vma, addr, end))
+			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))
+			continue;
+
+		addr = vma->vm_start;
+		end = vma->vm_end;
+		
+		pgd = pgd_offset(mm, addr);
+		do {
+			next = pgd_addr_end(addr, end);
+			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);
+
+void __ipipe_pin_range_globally(unsigned long start, unsigned long end)
+{
+	struct task_struct *p;
+
+	read_lock(&tasklist_lock);
+
+	for_each_process(p)
+		if (p->mm)
+			__ipipe_pin_range_mapping(p->mm, start, end);
+
+	read_unlock(&tasklist_lock);
+}
+
+#endif
diff --git a/mm/mlock.c b/mm/mlock.c
index 3446b7e..c67382d 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -162,10 +162,10 @@ asmlinkage long sys_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 a/mm/vmalloc.c b/mm/vmalloc.c
index 86897ee..c6076ff 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -156,6 +156,7 @@ int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
 		if (err)
 			break;
 	} while (pgd++, addr = next, addr != end);
+	__ipipe_pin_range_globally((unsigned long) area->addr, end);
 	flush_cache_vmap((unsigned long) area->addr, end);
 	return err;
 }
