[POWERPC] 4xx: UIC add mask_ack callback

This adds uic_mask_ack_irq() callback to PowerPC 4xx uic code
to avoid kernel crash. It is used for edge-triggered interrupts
by handle_uic_irq().

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/arch/powerpc/sysdev/uic.c b/arch/powerpc/sysdev/uic.c
index 5149716c734d..847a5496b869 100644
--- a/arch/powerpc/sysdev/uic.c
+++ b/arch/powerpc/sysdev/uic.c
@@ -97,6 +97,22 @@ static void uic_ack_irq(unsigned int virq)
         spin_unlock_irqrestore(&uic->lock, flags);
 }
 
+static void uic_mask_ack_irq(unsigned int virq)
+{
+        struct uic *uic = get_irq_chip_data(virq);
+        unsigned int src = uic_irq_to_hw(virq);
+        unsigned long flags;
+        u32 er, sr;
+
+        sr = 1 << (31-src);
+        spin_lock_irqsave(&uic->lock, flags);
+        er = mfdcr(uic->dcrbase + UIC_ER);
+        er &= ~sr;
+        mtdcr(uic->dcrbase + UIC_ER, er);
+        mtdcr(uic->dcrbase + UIC_SR, sr);
+        spin_unlock_irqrestore(&uic->lock, flags);
+}
+
 static int uic_set_irq_type(unsigned int virq, unsigned int flow_type)
 {
         struct uic *uic = get_irq_chip_data(virq);
@@ -152,7 +168,7 @@ static struct irq_chip uic_irq_chip = {
         .typename       = " UIC  ",
         .unmask         = uic_unmask_irq,
         .mask           = uic_mask_irq,
-/*      .mask_ack       = uic_mask_irq_and_ack, */
+        .mask_ack       = uic_mask_ack_irq,
         .ack            = uic_ack_irq,
         .set_type       = uic_set_irq_type,
 };