From 38792720c7f6d7dc04d33992c21b9d66442619d7 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@gmail.com>
Date: Tue, 24 Jun 2008 22:52:06 +0200
Subject: [PATCH] --- yaml --- r: 99899 b: refs/heads/master c:
 4de0043617f949fdac538fd59335e2150cd1b863 h: refs/heads/master i:   99897:
 4d817c75b6bbf4696c2b217e6b42860c9d978545   99895:
 95325c55b7c11f149c44a2fda5cca552802774a8 v: v3

---
 [refs]                      |  2 +-
 trunk/arch/x86/kernel/nmi.c | 13 ++++---------
 trunk/include/asm-x86/nmi.h | 13 +++++++++++++
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/[refs] b/[refs]
index 2d824d3d4dab..772e7870e7f8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c376d45432d935e6f1e0ff2d6be3734bcd3ba455
+refs/heads/master: 4de0043617f949fdac538fd59335e2150cd1b863
diff --git a/trunk/arch/x86/kernel/nmi.c b/trunk/arch/x86/kernel/nmi.c
index 32acda25e3cb..8dfe9db87a9e 100644
--- a/trunk/arch/x86/kernel/nmi.c
+++ b/trunk/arch/x86/kernel/nmi.c
@@ -119,10 +119,7 @@ int __init check_nmi_watchdog(void)
 	unsigned int *prev_nmi_count;
 	int cpu;
 
-	if (nmi_watchdog == NMI_NONE)
-		return 0;
-
-	if (!atomic_read(&nmi_active))
+	if (!nmi_watchdog_active() || !atomic_read(&nmi_active))
 		return 0;
 
 	prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
@@ -317,8 +314,7 @@ void setup_apic_nmi_watchdog(void *unused)
 void stop_apic_nmi_watchdog(void *unused)
 {
 	/* only support LOCAL and IO APICs for now */
-	if (nmi_watchdog != NMI_LOCAL_APIC &&
-	    nmi_watchdog != NMI_IO_APIC)
+	if (!nmi_watchdog_active())
 		return;
 	if (__get_cpu_var(wd_enabled) == 0)
 		return;
@@ -348,8 +344,7 @@ static DEFINE_PER_CPU(int, nmi_touch);
 
 void touch_nmi_watchdog(void)
 {
-	if (nmi_watchdog == NMI_LOCAL_APIC ||
-		nmi_watchdog == NMI_IO_APIC) {
+	if (nmi_watchdog_active()) {
 		unsigned cpu;
 
 		/*
@@ -474,7 +469,7 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
 	if (!!old_state == !!nmi_watchdog_enabled)
 		return 0;
 
-	if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_NONE) {
+	if (atomic_read(&nmi_active) < 0 || !nmi_watchdog_active()) {
 		printk(KERN_WARNING
 			"NMI watchdog is permanently disabled\n");
 		return -EIO;
diff --git a/trunk/include/asm-x86/nmi.h b/trunk/include/asm-x86/nmi.h
index 1348e542360f..21f8d0202a82 100644
--- a/trunk/include/asm-x86/nmi.h
+++ b/trunk/include/asm-x86/nmi.h
@@ -56,6 +56,19 @@ static inline void localise_nmi_watchdog(void)
 	if (nmi_watchdog == NMI_IO_APIC)
 		nmi_watchdog = NMI_LOCAL_APIC;
 }
+
+/* check if nmi_watchdog is active (ie was specified at boot) */
+static inline int nmi_watchdog_active(void)
+{
+	/*
+	 * actually it should be:
+	 * 	return (nmi_watchdog == NMI_LOCAL_APIC ||
+	 * 		nmi_watchdog == NMI_IO_APIC)
+	 * but since they are power of two we could use a
+	 * cheaper way --cvg
+	 */
+	return nmi_watchdog & 0x3;
+}
 #endif
 
 void lapic_watchdog_stop(void);