From e583538f077d5f70191670b47a046ba436ec3428 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sat, 5 Nov 2005 17:25:54 +0100 Subject: [PATCH] [PATCH] x86_64: Log machine checks from boot on Intel systems The logging for boot errors was turned off because it was broken on some AMD systems. But give Intel EM64T systems a chance because they are supposed to be correct there. The advantage is that there is a chance to actually log uncorrected machine checks after the reset. Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- Documentation/x86_64/boot-options.txt | 6 ++++-- arch/x86_64/kernel/mce.c | 14 +++++++++----- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index a83139692c..aaabb5883a 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -7,10 +7,12 @@ Machine check mce=off disable machine check mce=bootlog Enable logging of machine checks left over from booting. - Disabled by default because some BIOS leave bogus ones. + Disabled by default on AMD because some BIOS leave bogus ones. If your BIOS doesn't do that it's a good idea to enable though to make sure you log even machine check events that result - in a reboot. + in a reboot. On Intel systems it is enabled by default. + mce=nobootlog + Disable boot machine check logging. mce=tolerancelevel (number) 0: always panic, 1: panic if deadlock possible, 2: try to avoid panic, 3: never panic or exit (for testing) diff --git a/arch/x86_64/kernel/mce.c b/arch/x86_64/kernel/mce.c index cf8a76f0f4..183dc61054 100644 --- a/arch/x86_64/kernel/mce.c +++ b/arch/x86_64/kernel/mce.c @@ -37,7 +37,7 @@ static unsigned long bank[NR_BANKS] = { [0 ... NR_BANKS-1] = ~0UL }; static unsigned long console_logged; static int notify_user; static int rip_msr; -static int mce_bootlog; +static int mce_bootlog = 1; /* * Lockless MCE logging infrastructure. @@ -347,7 +347,11 @@ static void __cpuinit mce_cpu_quirks(struct cpuinfo_x86 *c) /* disable GART TBL walk error reporting, which trips off incorrectly with the IOMMU & 3ware & Cerberus. */ clear_bit(10, &bank[4]); + /* Lots of broken BIOS around that don't clear them + by default and leave crap in there. Don't log. */ + mce_bootlog = 0; } + } static void __cpuinit mce_cpu_features(struct cpuinfo_x86 *c) @@ -498,16 +502,16 @@ static int __init mcheck_disable(char *str) /* mce=off disables machine check. Note you can reenable it later using sysfs. mce=TOLERANCELEVEL (number, see above) - mce=bootlog Log MCEs from before booting. Disabled by default to work - around buggy BIOS that leave bogus MCEs. */ + mce=bootlog Log MCEs from before booting. Disabled by default on AMD. + mce=nobootlog Don't log MCEs from before booting. */ static int __init mcheck_enable(char *str) { if (*str == '=') str++; if (!strcmp(str, "off")) mce_dont_init = 1; - else if (!strcmp(str, "bootlog")) - mce_bootlog = 1; + else if (!strcmp(str, "bootlog") || !strcmp(str,"nobootlog")) + mce_bootlog = str[0] == 'b'; else if (isdigit(str[0])) get_option(&str, &tolerant); else -- 2.39.5