1 files changed, 63 insertions, 12 deletions

diff --git a/arch/powerpc/sysdev/uic.c b/arch/powerpc/sysdev/uic.c
index 89059895a20d..5149716c734d 100644
--- a/arch/powerpc/sysdev/uic.c
+++ b/arch/powerpc/sysdev/uic.c
@@ -24,6 +24,7 @@
 #include <linux/spinlock.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
 #include <asm/irq.h>
 #include <asm/io.h>
 #include <asm/prom.h>
@@ -55,9 +56,6 @@ struct uic {
 
         /* For secondary UICs, the cascade interrupt's irqaction */
         struct irqaction cascade;
-
-        /* The device node of the interrupt controller */
-        struct device_node *of_node;
 };
 
 static void uic_unmask_irq(unsigned int virq)
@@ -142,7 +140,7 @@ static int uic_set_irq_type(unsigned int virq, unsigned int flow_type)
 
         desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
         desc->status |= flow_type & IRQ_TYPE_SENSE_MASK;
-        if (trigger)
+        if (!trigger)
                 desc->status |= IRQ_LEVEL;
 
         spin_unlock_irqrestore(&uic->lock, flags);
@@ -159,10 +157,62 @@ static struct irq_chip uic_irq_chip = {
         .set_type       = uic_set_irq_type,
 };
 
-static int uic_host_match(struct irq_host *h, struct device_node *node)
+/**
+ *      handle_uic_irq - irq flow handler for UIC
+ *      @irq:   the interrupt number
+ *      @desc:  the interrupt description structure for this irq
+ *
+ * This is modified version of the generic handle_level_irq() suitable
+ * for the UIC.  On the UIC, acking (i.e. clearing the SR bit) a level
+ * irq will have no effect if the interrupt is still asserted by the
+ * device, even if the interrupt is already masked.  Therefore, unlike
+ * the standard handle_level_irq(), we must ack the interrupt *after*
+ * invoking the ISR (which should have de-asserted the interrupt in
+ * the external source).  For edge interrupts we ack at the beginning
+ * instead of the end, to keep the window in which we can miss an
+ * interrupt as small as possible.
+ */
+void fastcall handle_uic_irq(unsigned int irq, struct irq_desc *desc)
 {
-        struct uic *uic = h->host_data;
-        return uic->of_node == node;
+        unsigned int cpu = smp_processor_id();
+        struct irqaction *action;
+        irqreturn_t action_ret;
+
+        spin_lock(&desc->lock);
+        if (desc->status & IRQ_LEVEL)
+                desc->chip->mask(irq);
+        else
+                desc->chip->mask_ack(irq);
+
+        if (unlikely(desc->status & IRQ_INPROGRESS))
+                goto out_unlock;
+        desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
+        kstat_cpu(cpu).irqs[irq]++;
+
+        /*
+         * If its disabled or no action available
+         * keep it masked and get out of here
+         */
+        action = desc->action;
+        if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
+                desc->status |= IRQ_PENDING;
+                goto out_unlock;
+        }
+
+        desc->status |= IRQ_INPROGRESS;
+        desc->status &= ~IRQ_PENDING;
+        spin_unlock(&desc->lock);
+
+        action_ret = handle_IRQ_event(irq, action);
+
+        spin_lock(&desc->lock);
+        desc->status &= ~IRQ_INPROGRESS;
+        if (desc->status & IRQ_LEVEL)
+                desc->chip->ack(irq);
+        if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+                desc->chip->unmask(irq);
+out_unlock:
+        spin_unlock(&desc->lock);
 }
 
 static int uic_host_map(struct irq_host *h, unsigned int virq,
@@ -173,7 +223,7 @@ static int uic_host_map(struct irq_host *h, unsigned int virq,
         set_irq_chip_data(virq, uic);
         /* Despite the name, handle_level_irq() works for both level
          * and edge irqs on UIC.  FIXME: check this is correct */
-        set_irq_chip_and_handler(virq, &uic_irq_chip, handle_level_irq);
+        set_irq_chip_and_handler(virq, &uic_irq_chip, handle_uic_irq);
 
         /* Set default irq type */
         set_irq_type(virq, IRQ_TYPE_NONE);
@@ -194,7 +244,6 @@ static int uic_host_xlate(struct irq_host *h, struct device_node *ct,
 }
 
 static struct irq_host_ops uic_host_ops = {
-        .match  = uic_host_match,
         .map    = uic_host_map,
         .xlate  = uic_host_xlate,
 };
@@ -207,6 +256,9 @@ irqreturn_t uic_cascade(int virq, void *data)
         int subvirq;
 
         msr = mfdcr(uic->dcrbase + UIC_MSR);
+        if (!msr) /* spurious interrupt */
+                return IRQ_HANDLED;
+
         src = 32 - ffs(msr);
 
         subvirq = irq_linear_revmap(uic->irqhost, src);
@@ -229,7 +281,6 @@ static struct uic * __init uic_init_one(struct device_node *node)
 
         memset(uic, 0, sizeof(*uic));
         spin_lock_init(&uic->lock);
-        uic->of_node = of_node_get(node);
         indexp = of_get_property(node, "cell-index", &len);
         if (!indexp || (len != sizeof(u32))) {
                 printk(KERN_ERR "uic: Device node %s has missing or invalid "
@@ -246,8 +297,8 @@ static struct uic * __init uic_init_one(struct device_node *node)
         }
         uic->dcrbase = *dcrreg;
 
-        uic->irqhost = irq_alloc_host(IRQ_HOST_MAP_LINEAR, NR_UIC_INTS,
-                                      &uic_host_ops, -1);
+        uic->irqhost = irq_alloc_host(of_node_get(node), IRQ_HOST_MAP_LINEAR,
+                                      NR_UIC_INTS, &uic_host_ops, -1);
         if (! uic->irqhost) {
                 of_node_put(node);
                 return NULL; /* FIXME: panic? */