Blackfin arch: Update adeos blackfin arch patch to 1.9-00

Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

10 files changed, 241 insertions, 303 deletions

diff --git a/arch/blackfin/include/asm/ipipe.h b/arch/blackfin/include/asm/ipipe.h
index 76f53d8..343b563 100644
--- a/arch/blackfin/include/asm/ipipe.h
+++ b/arch/blackfin/include/asm/ipipe.h
@@ -35,9 +35,9 @@
 #include <asm/atomic.h>
 #include <asm/traps.h>
 
-#define IPIPE_ARCH_STRING     "1.8-00"
+#define IPIPE_ARCH_STRING     "1.9-00"
 #define IPIPE_MAJOR_NUMBER    1
-#define IPIPE_MINOR_NUMBER    8
+#define IPIPE_MINOR_NUMBER    9
 #define IPIPE_PATCH_NUMBER    0
 
 #ifdef CONFIG_SMP
@@ -83,9 +83,9 @@ struct ipipe_sysinfo {
 				"%2 = CYCLES2\n"		\
 				"CC = %2 == %0\n"		\
 				"if ! CC jump 1b\n"		\
-				: "=r" (((unsigned long *)&t)[1]),	\
-				  "=r" (((unsigned long *)&t)[0]),	\
-				  "=r" (__cy2)				\
+				: "=d,a" (((unsigned long *)&t)[1]),	\
+				  "=d,a" (((unsigned long *)&t)[0]),	\
+				  "=d,a" (__cy2)				\
 				: /*no input*/ : "CC");			\
 	t;								\
 	})
@@ -118,35 +118,40 @@ void __ipipe_disable_irqdesc(struct ipipe_domain *ipd,
 
 #define __ipipe_disable_irq(irq)	(irq_desc[irq].chip->mask(irq))
 
-#define __ipipe_lock_root()					\
-	set_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags)
+static inline int __ipipe_check_tickdev(const char *devname)
+{
+	return 1;
+}
 
-#define __ipipe_unlock_root()					\
-	clear_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags)
+static inline void __ipipe_lock_root(void)
+{
+	set_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status));
+}
+
+static inline void __ipipe_unlock_root(void)
+{
+	clear_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status));
+}
 
 void __ipipe_enable_pipeline(void);
 
 #define __ipipe_hook_critical_ipi(ipd) do { } while (0)
 
-#define __ipipe_sync_pipeline(syncmask)					\
-	do {								\
-		struct ipipe_domain *ipd = ipipe_current_domain;	\
-		if (likely(ipd != ipipe_root_domain || !test_bit(IPIPE_ROOTLOCK_FLAG, &ipd->flags))) \
-			__ipipe_sync_stage(syncmask);			\
-	} while (0)
+#define __ipipe_sync_pipeline  ___ipipe_sync_pipeline
+void ___ipipe_sync_pipeline(unsigned long syncmask);
 
 void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs);
 
 int __ipipe_get_irq_priority(unsigned irq);
 
-int __ipipe_get_irqthread_priority(unsigned irq);
-
 void __ipipe_stall_root_raw(void);
 
 void __ipipe_unstall_root_raw(void);
 
 void __ipipe_serial_debug(const char *fmt, ...);
 
+asmlinkage void __ipipe_call_irqtail(unsigned long addr);
+
 DECLARE_PER_CPU(struct pt_regs, __ipipe_tick_regs);
 
 extern unsigned long __ipipe_core_clock;
@@ -162,42 +167,25 @@ static inline unsigned long __ipipe_ffnz(unsigned long ul)
 
 #define __ipipe_run_irqtail()  /* Must be a macro */			\
 	do {								\
-		asmlinkage void __ipipe_call_irqtail(void);		\
 		unsigned long __pending;				\
-		CSYNC();					\
+		CSYNC();						\
 		__pending = bfin_read_IPEND();				\
 		if (__pending & 0x8000) {				\
 			__pending &= ~0x8010;				\
 			if (__pending && (__pending & (__pending - 1)) == 0) \
-				__ipipe_call_irqtail();			\
+				__ipipe_call_irqtail(__ipipe_irq_tail_hook); \
 		}							\
 	} while (0)
 
 #define __ipipe_run_isr(ipd, irq)					\
 	do {								\
 		if (ipd == ipipe_root_domain) {				\
-			/*						\
-			 * Note: the I-pipe implements a threaded interrupt model on \
-			 * this arch for Linux external IRQs. The interrupt handler we \
-			 * call here only wakes up the associated IRQ thread. \
-			 */						\
-			if (ipipe_virtual_irq_p(irq)) {			\
-				/* No irqtail here; virtual interrupts have no effect \
-				   on IPEND so there is no need for processing \
-				   deferral. */				\
-				local_irq_enable_nohead(ipd);		\
+			local_irq_enable_hw();				\
+			if (ipipe_virtual_irq_p(irq))			\
 				ipd->irqs[irq].handler(irq, ipd->irqs[irq].cookie); \
-				local_irq_disable_nohead(ipd);		\
-			} else						\
-				/*					\
-				 * No need to run the irqtail here either; \
-				 * we can't be preempted by hw IRQs, so	\
-				 * non-Linux IRQs cannot stack over the short \
-				 * thread wakeup code. Which in turn means \
-				 * that no irqtail condition could be pending \
-				 * for domains above Linux in the pipeline. \
-				 */					\
+			else						\
 				ipd->irqs[irq].handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs)); \
+			local_irq_disable_hw();				\
 		} else {						\
 			__clear_bit(IPIPE_SYNC_FLAG, &ipipe_cpudom_var(ipd, status)); \
 			local_irq_enable_nohead(ipd);			\
@@ -217,42 +205,24 @@ void ipipe_init_irq_threads(void);
 
 int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc);
 
-#define IS_SYSIRQ(irq)		((irq) > IRQ_CORETMR && (irq) <= SYS_IRQS)
-#define IS_GPIOIRQ(irq)		((irq) >= GPIO_IRQ_BASE && (irq) < NR_IRQS)
-
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+#define IRQ_SYSTMR		IRQ_CORETMR
+#define IRQ_PRIOTMR		IRQ_CORETMR
+#else
 #define IRQ_SYSTMR		IRQ_TIMER0
 #define IRQ_PRIOTMR		CONFIG_IRQ_TIMER0
+#endif
 
-#if defined(CONFIG_BF531) || defined(CONFIG_BF532) || defined(CONFIG_BF533)
-#define PRIO_GPIODEMUX(irq)	CONFIG_PFA
-#elif defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537)
-#define PRIO_GPIODEMUX(irq)	CONFIG_IRQ_PROG_INTA
-#elif defined(CONFIG_BF52x)
-#define PRIO_GPIODEMUX(irq)	((irq) == IRQ_PORTF_INTA ? CONFIG_IRQ_PORTF_INTA : \
-				 (irq) == IRQ_PORTG_INTA ? CONFIG_IRQ_PORTG_INTA : \
-				 (irq) == IRQ_PORTH_INTA ? CONFIG_IRQ_PORTH_INTA : \
-				 -1)
-#elif defined(CONFIG_BF561)
-#define PRIO_GPIODEMUX(irq)	((irq) == IRQ_PROG0_INTA ? CONFIG_IRQ_PROG0_INTA : \
-				 (irq) == IRQ_PROG1_INTA ? CONFIG_IRQ_PROG1_INTA : \
-				 (irq) == IRQ_PROG2_INTA ? CONFIG_IRQ_PROG2_INTA : \
-				 -1)
+#ifdef CONFIG_BF561
 #define bfin_write_TIMER_DISABLE(val)	bfin_write_TMRS8_DISABLE(val)
 #define bfin_write_TIMER_ENABLE(val)	bfin_write_TMRS8_ENABLE(val)
 #define bfin_write_TIMER_STATUS(val)	bfin_write_TMRS8_STATUS(val)
 #define bfin_read_TIMER_STATUS()	bfin_read_TMRS8_STATUS()
 #elif defined(CONFIG_BF54x)
-#define PRIO_GPIODEMUX(irq)	((irq) == IRQ_PINT0 ? CONFIG_IRQ_PINT0 : \
-				 (irq) == IRQ_PINT1 ? CONFIG_IRQ_PINT1 : \
-				 (irq) == IRQ_PINT2 ? CONFIG_IRQ_PINT2 : \
-				 (irq) == IRQ_PINT3 ? CONFIG_IRQ_PINT3 : \
-				 -1)
 #define bfin_write_TIMER_DISABLE(val)	bfin_write_TIMER_DISABLE0(val)
 #define bfin_write_TIMER_ENABLE(val)	bfin_write_TIMER_ENABLE0(val)
 #define bfin_write_TIMER_STATUS(val)	bfin_write_TIMER_STATUS0(val)
 #define bfin_read_TIMER_STATUS(val)	bfin_read_TIMER_STATUS0(val)
-#else
-# error "no PRIO_GPIODEMUX() for this part"
 #endif
 
 #define __ipipe_root_tick_p(regs)	((regs->ipend & 0x10) != 0)
@@ -275,4 +245,6 @@ int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc);
 
 #endif /* !CONFIG_IPIPE */
 
+#define ipipe_update_tick_evtdev(evtdev)	do { } while (0)
+
 #endif	/* !__ASM_BLACKFIN_IPIPE_H */
diff --git a/arch/blackfin/include/asm/ipipe_base.h b/arch/blackfin/include/asm/ipipe_base.h
index cb1025a..3e8acbd 100644
--- a/arch/blackfin/include/asm/ipipe_base.h
+++ b/arch/blackfin/include/asm/ipipe_base.h
@@ -1,5 +1,5 @@
 /*   -*- linux-c -*-
- *   include/asm-blackfin/_baseipipe.h
+ *   include/asm-blackfin/ipipe_base.h
  *
  *   Copyright (C) 2007 Philippe Gerum.
  *
@@ -27,8 +27,9 @@
 #define IPIPE_NR_XIRQS		NR_IRQS
 #define IPIPE_IRQ_ISHIFT	5	/* 2^5 for 32bits arch. */
 
-/* Blackfin-specific, global domain flags */
-#define IPIPE_ROOTLOCK_FLAG	1	/* Lock pipeline for root */
+/* Blackfin-specific, per-cpu pipeline status */
+#define IPIPE_SYNCDEFER_FLAG	15
+#define IPIPE_SYNCDEFER_MASK	(1L << IPIPE_SYNCDEFER_MASK)
 
  /* Blackfin traps -- i.e. exception vector numbers */
 #define IPIPE_NR_FAULTS		52 /* We leave a gap after VEC_ILL_RES. */
@@ -48,11 +49,6 @@
 
 #ifndef __ASSEMBLY__
 
-#include <linux/bitops.h>
-
-extern int test_bit(int nr, const void *addr);
-
-
 extern unsigned long __ipipe_root_status; /* Alias to ipipe_root_cpudom_var(status) */
 
 static inline void __ipipe_stall_root(void)
diff --git a/arch/blackfin/include/asm/irq.h b/arch/blackfin/include/asm/irq.h
index 3d97790..7645e85 100644
--- a/arch/blackfin/include/asm/irq.h
+++ b/arch/blackfin/include/asm/irq.h
@@ -61,20 +61,38 @@ void __ipipe_restore_root(unsigned long flags);
 #define raw_irqs_disabled_flags(flags)	(!irqs_enabled_from_flags_hw(flags))
 #define local_test_iflag_hw(x)		irqs_enabled_from_flags_hw(x)
 
-#define local_save_flags(x)						\
-	do {								\
-		(x) = __ipipe_test_root() ? \
+#define local_save_flags(x)					 \
+	do {							 \
+		(x) = __ipipe_test_root() ?			 \
 			__all_masked_irq_flags : bfin_irq_flags; \
+		barrier();					 \
 	} while (0)
 
-#define local_irq_save(x)				\
-	do {						\
-		(x) = __ipipe_test_and_stall_root();	\
+#define local_irq_save(x)					 \
+	do {						 	 \
+		(x) = __ipipe_test_and_stall_root() ?		 \
+			__all_masked_irq_flags : bfin_irq_flags; \
+		barrier();					 \
+	} while (0)
+
+static inline void local_irq_restore(unsigned long x)
+{
+	barrier();
+	__ipipe_restore_root(x == __all_masked_irq_flags);
+}
+
+#define local_irq_disable()			\
+	do {					\
+		__ipipe_stall_root();		\
+		barrier();			\
 	} while (0)
 
-#define local_irq_restore(x)	__ipipe_restore_root(x)
-#define local_irq_disable()	__ipipe_stall_root()
-#define local_irq_enable()	__ipipe_unstall_root()
+static inline void local_irq_enable(void)
+{
+	barrier();
+	__ipipe_unstall_root();
+}
+
 #define irqs_disabled()		__ipipe_test_root()
 
 #define local_save_flags_hw(x) \
diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index e721ce5..2920087 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -122,6 +122,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_MEMDIE              4
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
 #define TIF_FREEZE              6       /* is freezing for suspend */
+#define TIF_IRQ_SYNC            7       /* sync pipeline stage */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
@@ -130,6 +131,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_FREEZE             (1<<TIF_FREEZE)
+#define _TIF_IRQ_SYNC           (1<<TIF_IRQ_SYNC)
 
 #define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
 
diff --git a/arch/blackfin/kernel/ipipe.c b/arch/blackfin/kernel/ipipe.c
index 339be5a..a5de8d4 100644
--- a/arch/blackfin/kernel/ipipe.c
+++ b/arch/blackfin/kernel/ipipe.c
@@ -35,14 +35,8 @@
 #include <asm/atomic.h>
 #include <asm/io.h>
 
-static int create_irq_threads;
-
 DEFINE_PER_CPU(struct pt_regs, __ipipe_tick_regs);
 
-static DEFINE_PER_CPU(unsigned long, pending_irqthread_mask);
-
-static DEFINE_PER_CPU(int [IVG13 + 1], pending_irq_count);
-
 asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs);
 
 static void __ipipe_no_irqtail(void);
@@ -93,6 +87,7 @@ void __ipipe_enable_pipeline(void)
  */
 void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 {
+	struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr();
 	struct ipipe_domain *this_domain, *next_domain;
 	struct list_head *head, *pos;
 	int m_ack, s = -1;
@@ -104,7 +99,6 @@ void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 	 * interrupt.
 	 */
 	m_ack = (regs == NULL || irq == IRQ_SYSTMR || irq == IRQ_CORETMR);
-
 	this_domain = ipipe_current_domain;
 
 	if (unlikely(test_bit(IPIPE_STICKY_FLAG, &this_domain->irqs[irq].control)))
@@ -114,49 +108,28 @@ void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 		next_domain = list_entry(head, struct ipipe_domain, p_link);
 		if (likely(test_bit(IPIPE_WIRED_FLAG, &next_domain->irqs[irq].control))) {
 			if (!m_ack && next_domain->irqs[irq].acknowledge != NULL)
-				next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
-			if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
-				s = __test_and_set_bit(IPIPE_STALL_FLAG,
-						       &ipipe_root_cpudom_var(status));
+				next_domain->irqs[irq].acknowledge(irq, irq_to_desc(irq));
+			if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status))
+				s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status);
 			__ipipe_dispatch_wired(next_domain, irq);
-				goto finalize;
-			return;
+			goto out;
 		}
 	}
 
 	/* Ack the interrupt. */
 
 	pos = head;
-
 	while (pos != &__ipipe_pipeline) {
 		next_domain = list_entry(pos, struct ipipe_domain, p_link);
-		/*
-		 * For each domain handling the incoming IRQ, mark it
-		 * as pending in its log.
-		 */
 		if (test_bit(IPIPE_HANDLE_FLAG, &next_domain->irqs[irq].control)) {
-			/*
-			 * Domains that handle this IRQ are polled for
-			 * acknowledging it by decreasing priority
-			 * order. The interrupt must be made pending
-			 * _first_ in the domain's status flags before
-			 * the PIC is unlocked.
-			 */
 			__ipipe_set_irq_pending(next_domain, irq);
-
 			if (!m_ack && next_domain->irqs[irq].acknowledge != NULL) {
-				next_domain->irqs[irq].acknowledge(irq, irq_desc + irq);
+				next_domain->irqs[irq].acknowledge(irq, irq_to_desc(irq));
 				m_ack = 1;
 			}
 		}
-
-		/*
-		 * If the domain does not want the IRQ to be passed
-		 * down the interrupt pipe, exit the loop now.
-		 */
 		if (!test_bit(IPIPE_PASS_FLAG, &next_domain->irqs[irq].control))
 			break;
-
 		pos = next_domain->p_link.next;
 	}
 
@@ -166,18 +139,24 @@ void __ipipe_handle_irq(unsigned irq, struct pt_regs *regs)
 	 * immediately to the current domain if the interrupt has been
 	 * marked as 'sticky'. This search does not go beyond the
 	 * current domain in the pipeline. We also enforce the
-	 * additional root stage lock (blackfin-specific). */
+	 * additional root stage lock (blackfin-specific).
+	 */
+	if (test_bit(IPIPE_SYNCDEFER_FLAG, &p->status))
+		s = __test_and_set_bit(IPIPE_STALL_FLAG, &p->status);
 
-	if (test_bit(IPIPE_ROOTLOCK_FLAG, &ipipe_root_domain->flags))
-		s = __test_and_set_bit(IPIPE_STALL_FLAG,
-				       &ipipe_root_cpudom_var(status));
-finalize:
+	/*
+	 * If the interrupt preempted the head domain, then do not
+	 * even try to walk the pipeline, unless an interrupt is
+	 * pending for it.
+	 */
+	if (test_bit(IPIPE_AHEAD_FLAG, &this_domain->flags) &&
+	    ipipe_head_cpudom_var(irqpend_himask) == 0)
+		goto out;
 
 	__ipipe_walk_pipeline(head);
-
+out:
 	if (!s)
-		__clear_bit(IPIPE_STALL_FLAG,
-			    &ipipe_root_cpudom_var(status));
+		__clear_bit(IPIPE_STALL_FLAG, &p->status);
 }
 
 int __ipipe_check_root(void)
@@ -187,7 +166,7 @@ int __ipipe_check_root(void)
 
 void __ipipe_enable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
 {
-	struct irq_desc *desc = irq_desc + irq;
+	struct irq_desc *desc = irq_to_desc(irq);
 	int prio = desc->ic_prio;
 
 	desc->depth = 0;
@@ -199,7 +178,7 @@ EXPORT_SYMBOL(__ipipe_enable_irqdesc);
 
 void __ipipe_disable_irqdesc(struct ipipe_domain *ipd, unsigned irq)
 {
-	struct irq_desc *desc = irq_desc + irq;
+	struct irq_desc *desc = irq_to_desc(irq);
 	int prio = desc->ic_prio;
 
 	if (ipd != &ipipe_root &&
@@ -236,15 +215,18 @@ int __ipipe_syscall_root(struct pt_regs *regs)
 {
 	unsigned long flags;
 
-	/* We need to run the IRQ tail hook whenever we don't
+	/*
+	 * We need to run the IRQ tail hook whenever we don't
 	 * propagate a syscall to higher domains, because we know that
 	 * important operations might be pending there (e.g. Xenomai
-	 * deferred rescheduling). */
+	 * deferred rescheduling).
+	 */
 
-	if (!__ipipe_syscall_watched_p(current, regs->orig_p0)) {
+	if (regs->orig_p0 < NR_syscalls) {
 		void (*hook)(void) = (void (*)(void))__ipipe_irq_tail_hook;
 		hook();
-		return 0;
+		if ((current->flags & PF_EVNOTIFY) == 0)
+			return 0;
 	}
 
 	/*
@@ -312,112 +294,46 @@ int ipipe_trigger_irq(unsigned irq)
 {
 	unsigned long flags;
 
+#ifdef CONFIG_IPIPE_DEBUG
 	if (irq >= IPIPE_NR_IRQS ||
 	    (ipipe_virtual_irq_p(irq)
 	     && !test_bit(irq - IPIPE_VIRQ_BASE, &__ipipe_virtual_irq_map)))
 		return -EINVAL;
+#endif
 
 	local_irq_save_hw(flags);
-
 	__ipipe_handle_irq(irq, NULL);
-
 	local_irq_restore_hw(flags);
 
 	return 1;
 }
 
-/* Move Linux IRQ to threads. */
-
-static int do_irqd(void *__desc)
+asmlinkage void __ipipe_sync_root(void)
 {
-	struct irq_desc *desc = __desc;
-	unsigned irq = desc - irq_desc;
-	int thrprio = desc->thr_prio;
-	int thrmask = 1 << thrprio;
-	int cpu = smp_processor_id();
-	cpumask_t cpumask;
-
-	sigfillset(&current->blocked);
-	current->flags |= PF_NOFREEZE;
-	cpumask = cpumask_of_cpu(cpu);
-	set_cpus_allowed(current, cpumask);
-	ipipe_setscheduler_root(current, SCHED_FIFO, 50 + thrprio);
-
-	while (!kthread_should_stop()) {
-		local_irq_disable();
-		if (!(desc->status & IRQ_SCHEDULED)) {
-			set_current_state(TASK_INTERRUPTIBLE);
-resched:
-			local_irq_enable();
-			schedule();
-			local_irq_disable();
-		}
-		__set_current_state(TASK_RUNNING);
-		/*
-		 * If higher priority interrupt servers are ready to
-		 * run, reschedule immediately. We need this for the
-		 * GPIO demux IRQ handler to unmask the interrupt line
-		 * _last_, after all GPIO IRQs have run.
-		 */
-		if (per_cpu(pending_irqthread_mask, cpu) & ~(thrmask|(thrmask-1)))
-			goto resched;
-		if (--per_cpu(pending_irq_count[thrprio], cpu) == 0)
-			per_cpu(pending_irqthread_mask, cpu) &= ~thrmask;
-		desc->status &= ~IRQ_SCHEDULED;
-		desc->thr_handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs));
-		local_irq_enable();
-	}
-	__set_current_state(TASK_RUNNING);
-	return 0;
-}
+	unsigned long flags;
 
-static void kick_irqd(unsigned irq, void *cookie)
-{
-	struct irq_desc *desc = irq_desc + irq;
-	int thrprio = desc->thr_prio;
-	int thrmask = 1 << thrprio;
-	int cpu = smp_processor_id();
-
-	if (!(desc->status & IRQ_SCHEDULED)) {
-		desc->status |= IRQ_SCHEDULED;
-		per_cpu(pending_irqthread_mask, cpu) |= thrmask;
-		++per_cpu(pending_irq_count[thrprio], cpu);
-		wake_up_process(desc->thread);
-	}
-}
+	BUG_ON(irqs_disabled());
 
-int ipipe_start_irq_thread(unsigned irq, struct irq_desc *desc)
-{
-	if (desc->thread || !create_irq_threads)
-		return 0;
-
-	desc->thread = kthread_create(do_irqd, desc, "IRQ %d", irq);
-	if (desc->thread == NULL) {
-		printk(KERN_ERR "irqd: could not create IRQ thread %d!\n", irq);
-		return -ENOMEM;
-	}
+	local_irq_save_hw(flags);
 
-	wake_up_process(desc->thread);
+	clear_thread_flag(TIF_IRQ_SYNC);
 
-	desc->thr_handler = ipipe_root_domain->irqs[irq].handler;
-	ipipe_root_domain->irqs[irq].handler = &kick_irqd;
+	if (ipipe_root_cpudom_var(irqpend_himask) != 0)
+		__ipipe_sync_pipeline(IPIPE_IRQMASK_ANY);
 
-	return 0;
+	local_irq_restore_hw(flags);
 }
 
-void __init ipipe_init_irq_threads(void)
+void ___ipipe_sync_pipeline(unsigned long syncmask)
 {
-	unsigned irq;
-	struct irq_desc *desc;
-
-	create_irq_threads = 1;
+	struct ipipe_domain *ipd = ipipe_current_domain;
 
-	for (irq = 0; irq < NR_IRQS; irq++) {
-		desc = irq_desc + irq;
-		if (desc->action != NULL ||
-			(desc->status & IRQ_NOREQUEST) != 0)
-			ipipe_start_irq_thread(irq, desc);
+	if (ipd == ipipe_root_domain) {
+		if (test_bit(IPIPE_SYNCDEFER_FLAG, &ipipe_root_cpudom_var(status)))
+			return;
 	}
+
+	__ipipe_sync_stage(syncmask);
 }
 
 EXPORT_SYMBOL(show_stack);
diff --git a/arch/blackfin/kernel/irqchip.c b/arch/blackfin/kernel/irqchip.c
index 75724ee..7fd1265 100644
--- a/arch/blackfin/kernel/irqchip.c
+++ b/arch/blackfin/kernel/irqchip.c
@@ -144,11 +144,15 @@ asmlinkage void asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
 #endif
 	generic_handle_irq(irq);
 
-#ifndef CONFIG_IPIPE	/* Useless and bugous over the I-pipe: IRQs are threaded. */
-	/* If we're the only interrupt running (ignoring IRQ15 which is for
-	   syscalls), lower our priority to IRQ14 so that softirqs run at
-	   that level.  If there's another, lower-level interrupt, irq_exit
-	   will defer softirqs to that.  */
+#ifndef CONFIG_IPIPE
+	/*
+	 * If we're the only interrupt running (ignoring IRQ15 which
+	 * is for syscalls), lower our priority to IRQ14 so that
+	 * softirqs run at that level.  If there's another,
+	 * lower-level interrupt, irq_exit will defer softirqs to
+	 * that. If the interrupt pipeline is enabled, we are already
+	 * running at IRQ14 priority, so we don't need this code.
+	 */
 	CSYNC();
 	pending = bfin_read_IPEND() & ~0x8000;
 	other_ints = pending & (pending - 1);
diff --git a/arch/blackfin/kernel/time.c b/arch/blackfin/kernel/time.c
index 172b4c5..1bbacfb 100644
--- a/arch/blackfin/kernel/time.c
+++ b/arch/blackfin/kernel/time.c
@@ -134,7 +134,10 @@ irqreturn_t timer_interrupt(int irq, void *dummy)
 
 	write_seqlock(&xtime_lock);
 #if defined(CONFIG_TICK_SOURCE_SYSTMR0) && !defined(CONFIG_IPIPE)
-/* FIXME: Here TIMIL0 is not set when IPIPE enabled, why? */
+	/*
+	 * TIMIL0 is latched in __ipipe_grab_irq() when the I-Pipe is
+	 * enabled.
+	 */
 	if (get_gptimer_status(0) & TIMER_STATUS_TIMIL0) {
 #endif
 		do_timer(1);
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index 88de053..21e65a3 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -600,6 +600,19 @@ ENTRY(_system_call)
 	p2 = [p2];
 
 	[p2+(TASK_THREAD+THREAD_KSP)] = sp;
+#ifdef CONFIG_IPIPE
+	r0 = sp;
+	SP += -12;
+	call ___ipipe_syscall_root;
+	SP += 12;
+	cc = r0 == 1;
+	if cc jump .Lsyscall_really_exit;
+	cc = r0 == -1;
+	if cc jump .Lresume_userspace;
+	r3 = [sp + PT_R3];
+	r4 = [sp + PT_R4];
+	p0 = [sp + PT_ORIG_P0];
+#endif /* CONFIG_IPIPE */
 
 	/* Check the System Call */
 	r7 = __NR_syscall;
@@ -654,6 +667,17 @@ ENTRY(_system_call)
 	r7 =  r7 & r4;
 
 .Lsyscall_resched:
+#ifdef CONFIG_IPIPE
+	cc = BITTST(r7, TIF_IRQ_SYNC);
+	if !cc jump .Lsyscall_no_irqsync;
+	[--sp] = reti;
+	r0 = [sp++];
+	SP += -12;
+	call ___ipipe_sync_root;
+	SP += 12;
+	jump .Lresume_userspace_1;
+.Lsyscall_no_irqsync:
+#endif
 	cc = BITTST(r7, TIF_NEED_RESCHED);
 	if !cc jump .Lsyscall_sigpending;
 
@@ -685,6 +709,10 @@ ENTRY(_system_call)
 .Lsyscall_really_exit:
 	r5 = [sp + PT_RESERVED];
 	rets = r5;
+#ifdef CONFIG_IPIPE
+	[--sp] = reti;
+	r5 = [sp++];
+#endif /* CONFIG_IPIPE */
 	rts;
 ENDPROC(_system_call)
 
@@ -771,6 +799,15 @@ _new_old_task:
 ENDPROC(_resume)
 
 ENTRY(_ret_from_exception)
+#ifdef CONFIG_IPIPE
+	[--sp] = rets;
+	SP += -12;
+	call ___ipipe_check_root
+	SP += 12
+	rets = [sp++];
+	cc = r0 == 0;
+	if cc jump 4f;                /* not on behalf of Linux, get out */
+#endif /* CONFIG_IPIPE */
 	p2.l = lo(IPEND);
 	p2.h = hi(IPEND);
 
@@ -827,6 +864,28 @@ ENTRY(_ret_from_exception)
 	rts;
 ENDPROC(_ret_from_exception)
 
+#ifdef CONFIG_IPIPE
+
+_sync_root_irqs:
+	[--sp] = reti;		/* Reenable interrupts */
+	r0 = [sp++];
+	jump.l ___ipipe_sync_root
+
+_resume_kernel_from_int:
+	r0.l = _sync_root_irqs
+	r0.h = _sync_root_irqs
+	[--sp] = rets;
+	[--sp] = ( r7:4, p5:3 );
+	SP += -12;
+	call ___ipipe_call_irqtail
+	SP += 12;
+	( r7:4, p5:3 ) = [sp++];
+	rets = [sp++];
+	rts
+#else
+#define _resume_kernel_from_int	 2f
+#endif
+
 ENTRY(_return_from_int)
 	/* If someone else already raised IRQ 15, do nothing.  */
 	csync;
@@ -848,7 +907,7 @@ ENTRY(_return_from_int)
 	r1 = r0 - r1;
 	r2 = r0 & r1;
 	cc = r2 == 0;
-	if !cc jump 2f;
+	if !cc jump _resume_kernel_from_int;
 
 	/* Lower the interrupt level to 15.  */
 	p0.l = lo(EVT15);
diff --git a/arch/blackfin/mach-common/interrupt.S b/arch/blackfin/mach-common/interrupt.S
index 43c4eb9..0069c2d 100644
--- a/arch/blackfin/mach-common/interrupt.S
+++ b/arch/blackfin/mach-common/interrupt.S
@@ -235,6 +235,7 @@ ENDPROC(_evt_system_call)
 
 #ifdef CONFIG_IPIPE
 ENTRY(___ipipe_call_irqtail)
+	p0 = r0;
 	r0.l = 1f;
 	r0.h = 1f;
 	reti = r0;
@@ -242,9 +243,6 @@ ENTRY(___ipipe_call_irqtail)
 1:
 	[--sp] = rets;
 	[--sp] = ( r7:4, p5:3 );
-	p0.l = ___ipipe_irq_tail_hook;
-	p0.h = ___ipipe_irq_tail_hook;
-	p0 = [p0];
 	sp += -12;
 	call (p0);
 	sp += 12;
@@ -259,7 +257,7 @@ ENTRY(___ipipe_call_irqtail)
 	p0.h = hi(EVT14);
 	[p0] = r0;
 	csync;
-	r0 = 0x401f;
+	r0 = 0x401f (z);
 	sti r0;
 	raise 14;
 	[--sp] = reti;          /* IRQs on. */
@@ -277,11 +275,7 @@ ENTRY(___ipipe_call_irqtail)
 	p0.h = _bfin_irq_flags;
 	r0 = [p0];
 	sti r0;
-#if 0 /* FIXME: this actually raises scheduling latencies */
-	/* Reenable interrupts */
-	[--sp] = reti;
-	r0 = [sp++];
-#endif
 	rts;
 ENDPROC(___ipipe_call_irqtail)
+
 #endif /* CONFIG_IPIPE */
diff --git a/arch/blackfin/mach-common/ints-priority.c b/arch/blackfin/mach-common/ints-priority.c
index 2024945..a7d7b2d 100644
--- a/arch/blackfin/mach-common/ints-priority.c
+++ b/arch/blackfin/mach-common/ints-priority.c
@@ -161,11 +161,15 @@ static void bfin_core_unmask_irq(unsigned int irq)
 
 static void bfin_internal_mask_irq(unsigned int irq)
 {
+	unsigned long flags;
+
 #ifdef CONFIG_BF53x
+	local_irq_save_hw(flags);
 	bfin_write_SIC_IMASK(bfin_read_SIC_IMASK() &
 			     ~(1 << SIC_SYSIRQ(irq)));
 #else
 	unsigned mask_bank, mask_bit;
+	local_irq_save_hw(flags);
 	mask_bank = SIC_SYSIRQ(irq) / 32;
 	mask_bit = SIC_SYSIRQ(irq) % 32;
 	bfin_write_SIC_IMASK(mask_bank, bfin_read_SIC_IMASK(mask_bank) &
@@ -175,15 +179,20 @@ static void bfin_internal_mask_irq(unsigned int irq)
 			     ~(1 << mask_bit));
 #endif
 #endif
+	local_irq_restore_hw(flags);
 }
 
 static void bfin_internal_unmask_irq(unsigned int irq)
 {
+	unsigned long flags;
+
 #ifdef CONFIG_BF53x
+	local_irq_save_hw(flags);
 	bfin_write_SIC_IMASK(bfin_read_SIC_IMASK() |
 			     (1 << SIC_SYSIRQ(irq)));
 #else
 	unsigned mask_bank, mask_bit;
+	local_irq_save_hw(flags);
 	mask_bank = SIC_SYSIRQ(irq) / 32;
 	mask_bit = SIC_SYSIRQ(irq) % 32;
 	bfin_write_SIC_IMASK(mask_bank, bfin_read_SIC_IMASK(mask_bank) |
@@ -193,6 +202,7 @@ static void bfin_internal_unmask_irq(unsigned int irq)
 			     (1 << mask_bit));
 #endif
 #endif
+	local_irq_restore_hw(flags);
 }
 
 #ifdef CONFIG_PM
@@ -390,7 +400,7 @@ static void bfin_demux_error_irq(unsigned int int_err_irq,
 static inline void bfin_set_irq_handler(unsigned irq, irq_flow_handler_t handle)
 {
 #ifdef CONFIG_IPIPE
-	_set_irq_handler(irq, handle_edge_irq);
+	_set_irq_handler(irq, handle_level_irq);
 #else
 	struct irq_desc *desc = irq_desc + irq;
 	/* May not call generic set_irq_handler() due to spinlock
@@ -1055,13 +1065,18 @@ int __init init_arch_irq(void)
 #endif
 		default:
 #ifdef CONFIG_IPIPE
-	/*
-	 * We want internal interrupt sources to be masked, because
-	 * ISRs may trigger interrupts recursively (e.g. DMA), but
-	 * interrupts are _not_ masked at CPU level. So let's handle
-	 * them as level interrupts.
-	 */
-			set_irq_handler(irq, handle_level_irq);
+			/*
+			 * We want internal interrupt sources to be
+			 * masked, because ISRs may trigger interrupts
+			 * recursively (e.g. DMA), but interrupts are
+			 * _not_ masked at CPU level. So let's handle
+			 * most of them as level interrupts, except
+			 * the timer interrupt which is special.
+			 */
+			if (irq == IRQ_SYSTMR || irq == IRQ_CORETMR)
+				set_irq_handler(irq, handle_simple_irq);
+			else
+				set_irq_handler(irq, handle_level_irq);
 #else /* !CONFIG_IPIPE */
 			set_irq_handler(irq, handle_simple_irq);
 #endif /* !CONFIG_IPIPE */
@@ -1123,9 +1138,8 @@ int __init init_arch_irq(void)
 
 #ifdef CONFIG_IPIPE
 	for (irq = 0; irq < NR_IRQS; irq++) {
-		struct irq_desc *desc = irq_desc + irq;
+		struct irq_desc *desc = irq_to_desc(irq);
 		desc->ic_prio = __ipipe_get_irq_priority(irq);
-		desc->thr_prio = __ipipe_get_irqthread_priority(irq);
 	}
 #endif /* CONFIG_IPIPE */
 
@@ -1208,76 +1222,21 @@ int __ipipe_get_irq_priority(unsigned irq)
 	return IVG15;
 }
 
-int __ipipe_get_irqthread_priority(unsigned irq)
-{
-	int ient, prio;
-	int demux_irq;
-
-	/* The returned priority value is rescaled to [0..IVG13+1]
-	 * with 0 being the lowest effective priority level. */
-
-	if (irq <= IRQ_CORETMR)
-		return IVG13 - irq + 1;
-
-	/* GPIO IRQs are given the priority of the demux
-	 * interrupt. */
-	if (IS_GPIOIRQ(irq)) {
-#if defined(CONFIG_BF54x)
-		u32 bank = PINT_2_BANK(irq2pint_lut[irq - SYS_IRQS]);
-		demux_irq = (bank == 0 ? IRQ_PINT0 :
-				bank == 1 ? IRQ_PINT1 :
-				bank == 2 ? IRQ_PINT2 :
-				IRQ_PINT3);
-#elif defined(CONFIG_BF561)
-		demux_irq = (irq >= IRQ_PF32 ? IRQ_PROG2_INTA :
-				irq >= IRQ_PF16 ? IRQ_PROG1_INTA :
-				IRQ_PROG0_INTA);
-#elif defined(CONFIG_BF52x)
-		demux_irq = (irq >= IRQ_PH0 ? IRQ_PORTH_INTA :
-				irq >= IRQ_PG0 ? IRQ_PORTG_INTA :
-				IRQ_PORTF_INTA);
-#else
-		demux_irq = irq;
-#endif
-		return IVG13 - PRIO_GPIODEMUX(demux_irq) + 1;
-	}
-
-	/* The GPIO demux interrupt is given a lower priority
-	 * than the GPIO IRQs, so that its threaded handler
-	 * unmasks the interrupt line after the decoded IRQs
-	 * have been processed. */
-	prio = PRIO_GPIODEMUX(irq);
-	/* demux irq? */
-	if (prio != -1)
-		return IVG13 - prio;
-
-	for (ient = 0; ient < NR_PERI_INTS; ient++) {
-		struct ivgx *ivg = ivg_table + ient;
-		if (ivg->irqno == irq) {
-			for (prio = 0; prio <= IVG13-IVG7; prio++) {
-				if (ivg7_13[prio].ifirst <= ivg &&
-				    ivg7_13[prio].istop > ivg)
-					return IVG7 - prio;
-			}
-		}
-	}
-
-	return 0;
-}
-
 /* Hw interrupts are disabled on entry (check SAVE_CONTEXT). */
 #ifdef CONFIG_DO_IRQ_L1
 __attribute__((l1_text))
 #endif
 asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs)
 {
+	struct ipipe_percpu_domain_data *p = ipipe_root_cpudom_ptr();
+	struct ipipe_domain *this_domain = ipipe_current_domain;
 	struct ivgx *ivg_stop = ivg7_13[vec-IVG7].istop;
 	struct ivgx *ivg = ivg7_13[vec-IVG7].ifirst;
-	int irq;
+	int irq, s;
 
 	if (likely(vec == EVT_IVTMR_P)) {
 		irq = IRQ_CORETMR;
-		goto handle_irq;
+		goto core_tick;
 	}
 
 	SSYNC();
@@ -1319,24 +1278,39 @@ asmlinkage int __ipipe_grab_irq(int vec, struct pt_regs *regs)
 	irq = ivg->irqno;
 
 	if (irq == IRQ_SYSTMR) {
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+core_tick:
+#else
 		bfin_write_TIMER_STATUS(1); /* Latch TIMIL0 */
+#endif
 		/* This is basically what we need from the register frame. */
 		__raw_get_cpu_var(__ipipe_tick_regs).ipend = regs->ipend;
 		__raw_get_cpu_var(__ipipe_tick_regs).pc = regs->pc;
-		if (!ipipe_root_domain_p)
-			__raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10;
-		else
+		if (this_domain != ipipe_root_domain)
 			__raw_get_cpu_var(__ipipe_tick_regs).ipend &= ~0x10;
+		else
+			__raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10;
 	}
 
-handle_irq:
+#ifndef CONFIG_GENERIC_CLOCKEVENTS
+core_tick:
+#endif
+	if (this_domain == ipipe_root_domain) {
+		s = __test_and_set_bit(IPIPE_SYNCDEFER_FLAG, &p->status);
+		barrier();
+	}
 
 	ipipe_trace_irq_entry(irq);
 	__ipipe_handle_irq(irq, regs);
-       ipipe_trace_irq_exit(irq);
+	ipipe_trace_irq_exit(irq);
 
-       if (ipipe_root_domain_p)
-		return !test_bit(IPIPE_STALL_FLAG, &ipipe_root_cpudom_var(status));
+	if (this_domain == ipipe_root_domain) {
+		set_thread_flag(TIF_IRQ_SYNC);
+		if (!s) {
+			__clear_bit(IPIPE_SYNCDEFER_FLAG, &p->status);
+			return !test_bit(IPIPE_STALL_FLAG, &p->status);
+		}
+	}
 
        return 0;
 }