3 files changed, 59 insertions, 136 deletions

diff --git a/arch/blackfin/kernel/ipipe.c b/arch/blackfin/kernel/ipipe.c
index 339be5a3ae6a..a5de8d45424c 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 75724eee6494..7fd126564846 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 172b4c588467..1bbacfbd4c5d 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);