[PATCH 8/8] x86/mce: Update bootlog description to reflect behavior on AMD

From: Borislav Petkov
Date: Tue Jun 13 2017 - 12:30:31 EST


From: Yazen Ghannam <yazen.ghannam@xxxxxxx>

The bootlog option is only disabled by default on AMD Fam10h and older
systems.

Update bootlog description to say this. Change the family value to hex
to avoid confusion.

Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1497037244-48540-1-git-send-email-Yazen.Ghannam@xxxxxxx
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
Documentation/x86/x86_64/boot-options.txt | 3 ++-
arch/x86/kernel/cpu/mcheck/mce.c | 5 +++--
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index 61b611e9eeaf..b297c48389b9 100644
--- a/Documentation/x86/x86_64/boot-options.txt
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -36,7 +36,8 @@ Machine check
to broadcast MCEs.
mce=bootlog
Enable logging of machine checks left over from booting.
- Disabled by default on AMD because some BIOS leave bogus ones.
+ Disabled by default on AMD Fam10h and older 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. On Intel systems it is enabled by default.
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 3c54c2b9efc2..b58b77808ce4 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1550,7 +1550,7 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
*/
clear_bit(10, (unsigned long *)&mce_banks[4].ctl);
}
- if (c->x86 < 17 && cfg->bootlog < 0) {
+ if (c->x86 < 0x11 && cfg->bootlog < 0) {
/*
* Lots of broken BIOS around that don't clear them
* by default and leave crap in there. Don't log:
@@ -1832,7 +1832,8 @@ void mce_disable_bank(int bank)
* mce=TOLERANCELEVEL[,monarchtimeout] (number, see above)
* monarchtimeout is how long to wait for other CPUs on machine
* check, or 0 to not wait
- * mce=bootlog Log MCEs from before booting. Disabled by default on AMD.
+ * mce=bootlog Log MCEs from before booting. Disabled by default on AMD Fam10h
+ and older.
* mce=nobootlog Don't log MCEs from before booting.
* mce=bios_cmci_threshold Don't program the CMCI threshold
* mce=recovery force enable memcpy_mcsafe()
--
2.13.0