From d4d25deca49ec2527a634557bf5a6cf449f85deb Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
Date: Mon, 26 Nov 2007 20:42:19 +0100
Subject: [PATCH] x86: fix NMI watchdog & 'stopped time' problem
More than 3 years ago Niclas Gustafsson reported a 'stopped time'
problem:
> Watching the /proc/interrupts with 10s apart after the "stop".
>
> [root@s151 root]# more /proc/interrupts
> CPU0
> 0: 66413955 local-APIC-edge timer
[...]
> LOC: 67355837
> ERR: 0
> MIS: 0
> [root@s151 root]# more /proc/interrupts
> CPU0
> 0: 66413955 local-APIC-edge timer
[...]
> LOC: 67379568
> ERR: 0
> MIS: 0
This may be because buggy SMM firmware messes with the 8259A (configured
for a transparent mode -- yes that rare "local-APIC-edge" mode is tricky
;-) ) insanely.
this should resolve:
http://bugzilla.kernel.org/show_bug.cgi?id=2544
http://bugzilla.kernel.org/show_bug.cgi?id=6296
Patch-dusted-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/io_apic_32.c | 12 ++++++++++--
arch/x86/kernel/nmi_32.c | 9 +++++++--
2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index f35c6eb33da9b..fc4bbc1d13310 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -2166,6 +2166,10 @@ static inline void __init check_timer(void)
{
int apic1, pin1, apic2, pin2;
int vector;
+ unsigned int ver;
+
+ ver = apic_read(APIC_LVR);
+ ver = GET_APIC_VERSION(ver);
/*
* get/set the timer IRQ vector:
@@ -2179,11 +2183,15 @@ static inline void __init check_timer(void)
* mode for the 8259A whenever interrupts are routed
* through I/O APICs. Also IRQ0 has to be enabled in
* the 8259A which implies the virtual wire has to be
- * disabled in the local APIC.
+ * disabled in the local APIC. Finally timer interrupts
+ * need to be acknowledged manually in the 8259A for
+ * timer_interrupt() and for the i82489DX when using
+ * the NMI watchdog.
*/
apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
init_8259A(1);
- timer_ack = 1;
+ timer_ack = !cpu_has_tsc;
+ timer_ack |= (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver));
if (timer_over_8254 > 0)
enable_8259A_irq(0);
diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
index 600fd404e4401..f5cc47c60b137 100644
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi_32.c
@@ -25,6 +25,7 @@
#include <asm/smp.h>
#include <asm/nmi.h>
+#include <asm/timer.h>
#include "mach_traps.h"
@@ -83,7 +84,7 @@ static int __init check_nmi_watchdog(void)
prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
if (!prev_nmi_count)
- return -1;
+ goto error;
printk(KERN_INFO "Testing NMI watchdog ... ");
@@ -117,7 +118,7 @@ static int __init check_nmi_watchdog(void)
if (!atomic_read(&nmi_active)) {
kfree(prev_nmi_count);
atomic_set(&nmi_active, -1);
- return -1;
+ goto error;
}
printk("OK.\n");
@@ -128,6 +129,10 @@ static int __init check_nmi_watchdog(void)
kfree(prev_nmi_count);
return 0;
+error:
+ timer_ack = !cpu_has_tsc;
+
+ return -1;
}
/* This needs to happen later in boot so counters are working */
late_initcall(check_nmi_watchdog);
--
GitLab