From: George Beshers <gbeshers@redhat.com>
Date: Thu, 31 Jul 2008 15:33:45 -0400
Subject: [IA64] Clean up CPE handler registration
Message-id: 20080731192750.4411.77503.sendpatchset@dhcp-100-2-194.bos.redhat.com
O-Subject: [RHEL5.3 PATCH 13/19] [IA64] Clean up CPE handler registration
Bugzilla: 455308
RH-Acked-by: Prarit Bhargava <prarit@redhat.com>

[IA64] Clean up CPE handler registration

BZ#455308

Upstream: http://git.kernel.org/?p=linux/kernel/git/aegl/linux-2.6.git;a=commitdiff;h=a1287476e86568374ed6aadbb4123d9eff6f7b09

[IA64] Clean up CPE handler registration

Use local_vector_to_irq() instead of looping through all NR_IRQS.
This avoids registering the CPE handler on multiple irqs.  Only
register if the irq is valid.  If no valid irq is found, print an
error message and set up polling.

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index 7f09dd5..b90c505 100644
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -2007,22 +2007,26 @@ ia64_mca_late_init(void)
 
 		if (cpe_vector >= 0) {
 			/* If platform supports CPEI, enable the irq. */
-			cpe_poll_enabled = 0;
-			for (irq = 0; irq < NR_IRQS; ++irq)
-				if (irq_to_vector(irq) == cpe_vector) {
-					desc = irq_desc + irq;
-					desc->status |= IRQ_PER_CPU;
-					setup_irq(irq, &mca_cpe_irqaction);
-					ia64_cpe_irq = irq;
-				}
-			ia64_mca_register_cpev(cpe_vector);
-			IA64_MCA_DEBUG("%s: CPEI/P setup and enabled.\n", __FUNCTION__);
-		} else {
-			/* If platform doesn't support CPEI, get the timer going. */
-			if (cpe_poll_enabled) {
-				ia64_mca_cpe_poll(0UL);
-				IA64_MCA_DEBUG("%s: CPEP setup and enabled.\n", __FUNCTION__);
+			irq = local_vector_to_irq(cpe_vector);
+			if (irq > 0) {
+				cpe_poll_enabled = 0;
+				desc = irq_desc + irq;
+				desc->status |= IRQ_PER_CPU;
+				setup_irq(irq, &mca_cpe_irqaction);
+				ia64_cpe_irq = irq;
+				ia64_mca_register_cpev(cpe_vector);
+				IA64_MCA_DEBUG("%s: CPEI/P setup and enabled.\n",
+					__FUNCTION__);
+				return 0;
 			}
+			printk(KERN_ERR "%s: Failed to find irq for CPE "
+					"interrupt handler, vector %d\n",
+					__FUNCTION__, cpe_vector);
+		}
+		/* If platform doesn't support CPEI, get the timer going. */
+		if (cpe_poll_enabled) {
+			ia64_mca_cpe_poll(0UL);
+			IA64_MCA_DEBUG("%s: CPEP setup and enabled.\n", __FUNCTION__);
 		}
 	}
 #endif