From: Jan Beulich <jbeulich@novell.com>
Date: Fri, 1 Jul 2011 19:43:02 +0000 (+0100)
Subject: x86: adjust pirq_spin_lock_irq_desc()
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~10083
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22?a=commitdiff_plain;h=9e71918d4f039e5e4806493bd3310c8ceecedd08;p=xen.git

x86: adjust pirq_spin_lock_irq_desc()

Remove unnecessary/bogus assertions and add retry loop matching
domain_spin_lock_irq_desc().

Signed-off-by: Jan Beulich <jbeulich@novell.com>
---

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index f3cb34a7ee..b46fa9b8cb 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -968,30 +968,31 @@ struct irq_desc *domain_spin_lock_irq_desc(
 }
 
 /*
- * Same with struct pirq already looked up, and d->event_lock already
- * held (thus the PIRQ <-> IRQ mapping can't change under our feet).
+ * Same with struct pirq already looked up.
  */
 struct irq_desc *pirq_spin_lock_irq_desc(
     struct domain *d, const struct pirq *pirq, unsigned long *pflags)
 {
-    int irq = pirq->arch.irq;
     struct irq_desc *desc;
     unsigned long flags;
 
-    ASSERT(spin_is_locked(&d->event_lock));
+    for ( ; ; )
+    {
+        int irq = pirq->arch.irq;
 
-    if ( irq <= 0 )
-        return NULL;
+        if ( irq <= 0 )
+            return NULL;
 
-    desc = irq_to_desc(irq);
-    spin_lock_irqsave(&desc->lock, flags);
+        desc = irq_to_desc(irq);
+        spin_lock_irqsave(&desc->lock, flags);
+        if ( irq == pirq->arch.irq )
+            break;
+        spin_unlock_irqrestore(&desc->lock, flags);
+    }
 
     if ( pflags )
         *pflags = flags;
 
-    ASSERT(pirq == pirq_info(d, domain_irq_to_pirq(d, irq)));
-    ASSERT(irq == pirq->arch.irq);
-
     return desc;
 }