Kernel bump from 4.1.3-rt to 4.1.7-rt.
[kvmfornfv.git] / kernel / kernel / irq / manage.c
index 1b5c50a..79c55c2 100644 (file)
@@ -772,6 +772,12 @@ static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
        return IRQ_NONE;
 }
 
+static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
+{
+       WARN(1, "Secondary action handler called for irq %d\n", irq);
+       return IRQ_NONE;
+}
+
 static int irq_wait_for_interrupt(struct irqaction *action)
 {
        set_current_state(TASK_INTERRUPTIBLE);
@@ -798,7 +804,8 @@ static int irq_wait_for_interrupt(struct irqaction *action)
 static void irq_finalize_oneshot(struct irq_desc *desc,
                                 struct irqaction *action)
 {
-       if (!(desc->istate & IRQS_ONESHOT))
+       if (!(desc->istate & IRQS_ONESHOT) ||
+           action->handler == irq_forced_secondary_handler)
                return;
 again:
        chip_bus_lock(desc);
@@ -960,6 +967,18 @@ static void irq_thread_dtor(struct callback_head *unused)
        irq_finalize_oneshot(desc, action);
 }
 
+static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
+{
+       struct irqaction *secondary = action->secondary;
+
+       if (WARN_ON_ONCE(!secondary))
+               return;
+
+       raw_spin_lock_irq(&desc->lock);
+       __irq_wake_thread(desc, secondary);
+       raw_spin_unlock_irq(&desc->lock);
+}
+
 /*
  * Interrupt handler thread
  */
@@ -990,6 +1009,8 @@ static int irq_thread(void *data)
                action_ret = handler_fn(desc, action);
                if (action_ret == IRQ_HANDLED)
                        atomic_inc(&desc->threads_handled);
+               if (action_ret == IRQ_WAKE_THREAD)
+                       irq_wake_secondary(desc, action);
 
 #ifdef CONFIG_PREEMPT_RT_FULL
                migrate_disable();
@@ -1040,20 +1061,36 @@ void irq_wake_thread(unsigned int irq, void *dev_id)
 }
 EXPORT_SYMBOL_GPL(irq_wake_thread);
 
-static void irq_setup_forced_threading(struct irqaction *new)
+static int irq_setup_forced_threading(struct irqaction *new)
 {
        if (!force_irqthreads)
-               return;
+               return 0;
        if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
-               return;
+               return 0;
 
        new->flags |= IRQF_ONESHOT;
 
-       if (!new->thread_fn) {
-               set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
-               new->thread_fn = new->handler;
-               new->handler = irq_default_primary_handler;
+       /*
+        * Handle the case where we have a real primary handler and a
+        * thread handler. We force thread them as well by creating a
+        * secondary action.
+        */
+       if (new->handler != irq_default_primary_handler && new->thread_fn) {
+               /* Allocate the secondary action */
+               new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
+               if (!new->secondary)
+                       return -ENOMEM;
+               new->secondary->handler = irq_forced_secondary_handler;
+               new->secondary->thread_fn = new->thread_fn;
+               new->secondary->dev_id = new->dev_id;
+               new->secondary->irq = new->irq;
+               new->secondary->name = new->name;
        }
+       /* Deal with the primary handler */
+       set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
+       new->thread_fn = new->handler;
+       new->handler = irq_default_primary_handler;
+       return 0;
 }
 
 static int irq_request_resources(struct irq_desc *desc)
@@ -1073,6 +1110,48 @@ static void irq_release_resources(struct irq_desc *desc)
                c->irq_release_resources(d);
 }
 
+static int
+setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
+{
+       struct task_struct *t;
+       struct sched_param param = {
+               .sched_priority = MAX_USER_RT_PRIO/2,
+       };
+
+       if (!secondary) {
+               t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
+                                  new->name);
+       } else {
+               t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
+                                  new->name);
+               param.sched_priority += 1;
+       }
+
+       if (IS_ERR(t))
+               return PTR_ERR(t);
+
+       sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
+
+       /*
+        * We keep the reference to the task struct even if
+        * the thread dies to avoid that the interrupt code
+        * references an already freed task_struct.
+        */
+       get_task_struct(t);
+       new->thread = t;
+       /*
+        * Tell the thread to set its affinity. This is
+        * important for shared interrupt handlers as we do
+        * not invoke setup_affinity() for the secondary
+        * handlers as everything is already set up. Even for
+        * interrupts marked with IRQF_NO_BALANCE this is
+        * correct as we want the thread to move to the cpu(s)
+        * on which the requesting code placed the interrupt.
+        */
+       set_bit(IRQTF_AFFINITY, &new->thread_flags);
+       return 0;
+}
+
 /*
  * Internal function to register an irqaction - typically used to
  * allocate special interrupts that are part of the architecture.
@@ -1093,6 +1172,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
        if (!try_module_get(desc->owner))
                return -ENODEV;
 
+       new->irq = irq;
+
        /*
         * Check whether the interrupt nests into another interrupt
         * thread.
@@ -1110,8 +1191,11 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 */
                new->handler = irq_nested_primary_handler;
        } else {
-               if (irq_settings_can_thread(desc))
-                       irq_setup_forced_threading(new);
+               if (irq_settings_can_thread(desc)) {
+                       ret = irq_setup_forced_threading(new);
+                       if (ret)
+                               goto out_mput;
+               }
        }
 
        /*
@@ -1120,37 +1204,14 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
         * thread.
         */
        if (new->thread_fn && !nested) {
-               struct task_struct *t;
-               static const struct sched_param param = {
-                       .sched_priority = MAX_USER_RT_PRIO/2,
-               };
-
-               t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
-                                  new->name);
-               if (IS_ERR(t)) {
-                       ret = PTR_ERR(t);
+               ret = setup_irq_thread(new, irq, false);
+               if (ret)
                        goto out_mput;
+               if (new->secondary) {
+                       ret = setup_irq_thread(new->secondary, irq, true);
+                       if (ret)
+                               goto out_thread;
                }
-
-               sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
-
-               /*
-                * We keep the reference to the task struct even if
-                * the thread dies to avoid that the interrupt code
-                * references an already freed task_struct.
-                */
-               get_task_struct(t);
-               new->thread = t;
-               /*
-                * Tell the thread to set its affinity. This is
-                * important for shared interrupt handlers as we do
-                * not invoke setup_affinity() for the secondary
-                * handlers as everything is already set up. Even for
-                * interrupts marked with IRQF_NO_BALANCE this is
-                * correct as we want the thread to move to the cpu(s)
-                * on which the requesting code placed the interrupt.
-                */
-               set_bit(IRQTF_AFFINITY, &new->thread_flags);
        }
 
        if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
@@ -1326,7 +1387,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                                   irq, nmsk, omsk);
        }
 
-       new->irq = irq;
        *old_ptr = new;
 
        irq_pm_install_action(desc, new);
@@ -1352,6 +1412,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
         */
        if (new->thread)
                wake_up_process(new->thread);
+       if (new->secondary)
+               wake_up_process(new->secondary->thread);
 
        register_irq_proc(irq, desc);
        new->dir = NULL;
@@ -1382,6 +1444,13 @@ out_thread:
                kthread_stop(t);
                put_task_struct(t);
        }
+       if (new->secondary && new->secondary->thread) {
+               struct task_struct *t = new->secondary->thread;
+
+               new->secondary->thread = NULL;
+               kthread_stop(t);
+               put_task_struct(t);
+       }
 out_mput:
        module_put(desc->owner);
        return ret;
@@ -1489,9 +1558,14 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
        if (action->thread) {
                kthread_stop(action->thread);
                put_task_struct(action->thread);
+               if (action->secondary && action->secondary->thread) {
+                       kthread_stop(action->secondary->thread);
+                       put_task_struct(action->secondary->thread);
+               }
        }
 
        module_put(desc->owner);
+       kfree(action->secondary);
        return action;
 }
 
@@ -1635,8 +1709,10 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler,
        retval = __setup_irq(irq, desc, action);
        chip_bus_sync_unlock(desc);
 
-       if (retval)
+       if (retval) {
+               kfree(action->secondary);
                kfree(action);
+       }
 
 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
        if (!retval && (irqflags & IRQF_SHARED)) {