Merge branches 's390', 'arm/renesas', 'arm/msm', 'arm/shmobile', 'arm/smmu', 'x86...

[cascardo/linux.git] / arch / powerpc / platforms / powernv / opal-irqchip.c

diff --git a/arch/powerpc/platforms/powernv/opal-irqchip.c b/arch/powerpc/platforms/powernv/opal-irqchip.c
index 6ccfb6c..e505223 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal-irqchip.c
+++ b/arch/powerpc/platforms/powernv/opal-irqchip.c
@@ -43,11 +43,34 @@ static unsigned int opal_irq_count;
 static unsigned int *opal_irqs;
 
 static void opal_handle_irq_work(struct irq_work *work);
-static __be64 last_outstanding_events;
+static u64 last_outstanding_events;
 static struct irq_work opal_event_irq_work = {
        .func = opal_handle_irq_work,
 };
 
+void opal_handle_events(uint64_t events)
+{
+       int virq, hwirq = 0;
+       u64 mask = opal_event_irqchip.mask;
+
+       if (!in_irq() && (events & mask)) {
+               last_outstanding_events = events;
+               irq_work_queue(&opal_event_irq_work);
+               return;
+       }
+
+       while (events & mask) {
+               hwirq = fls64(events) - 1;
+               if (BIT_ULL(hwirq) & mask) {
+                       virq = irq_find_mapping(opal_event_irqchip.domain,
+                                               hwirq);
+                       if (virq)
+                               generic_handle_irq(virq);
+               }
+               events &= ~BIT_ULL(hwirq);
+       }
+}
+
 static void opal_event_mask(struct irq_data *d)
 {
        clear_bit(d->hwirq, &opal_event_irqchip.mask);
@@ -55,9 +78,21 @@ static void opal_event_mask(struct irq_data *d)
 
 static void opal_event_unmask(struct irq_data *d)
 {
+       __be64 events;
+
        set_bit(d->hwirq, &opal_event_irqchip.mask);
 
-       opal_poll_events(&last_outstanding_events);
+       opal_poll_events(&events);
+       last_outstanding_events = be64_to_cpu(events);
+
+       /*
+        * We can't just handle the events now with opal_handle_events().
+        * If we did we would deadlock when opal_event_unmask() is called from
+        * handle_level_irq() with the irq descriptor lock held, because
+        * calling opal_handle_events() would call generic_handle_irq() and
+        * then handle_level_irq() which would try to take the descriptor lock
+        * again. Instead queue the events for later.
+        */
        if (last_outstanding_events & opal_event_irqchip.mask)
                /* Need to retrigger the interrupt */
                irq_work_queue(&opal_event_irq_work);
@@ -96,29 +131,6 @@ static int opal_event_map(struct irq_domain *d, unsigned int irq,
        return 0;
 }
 
-void opal_handle_events(uint64_t events)
-{
-       int virq, hwirq = 0;
-       u64 mask = opal_event_irqchip.mask;
-
-       if (!in_irq() && (events & mask)) {
-               last_outstanding_events = events;
-               irq_work_queue(&opal_event_irq_work);
-               return;
-       }
-
-       while (events & mask) {
-               hwirq = fls64(events) - 1;
-               if (BIT_ULL(hwirq) & mask) {
-                       virq = irq_find_mapping(opal_event_irqchip.domain,
-                                               hwirq);
-                       if (virq)
-                               generic_handle_irq(virq);
-               }
-               events &= ~BIT_ULL(hwirq);
-       }
-}
-
 static irqreturn_t opal_interrupt(int irq, void *data)
 {
        __be64 events;
@@ -131,7 +143,7 @@ static irqreturn_t opal_interrupt(int irq, void *data)
 
 static void opal_handle_irq_work(struct irq_work *work)
 {
-       opal_handle_events(be64_to_cpu(last_outstanding_events));
+       opal_handle_events(last_outstanding_events);
 }
 
 static int opal_event_match(struct irq_domain *h, struct device_node *node,