Commit d1992996 authored by Emanuel Czirai's avatar Emanuel Czirai Committed by Thomas Gleixner

x86/AMD: Apply erratum 665 on machines without a BIOS fix

AMD F12h machines have an erratum which can cause DIV/IDIV to behave
unpredictably. The workaround is to set MSRC001_1029[31] but sometimes
there is no BIOS update containing that workaround so let's do it
ourselves unconditionally. It is simple enough.

[ Borislav: Wrote commit message. ]
Signed-off-by: default avatarEmanuel Czirai <icanrealizeum@gmail.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Yaowu Xu <yaowu@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160902053550.18097-1-bp@alien8.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 3eab887a
......@@ -669,6 +669,17 @@ static void init_amd_gh(struct cpuinfo_x86 *c)
set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
}
#define MSR_AMD64_DE_CFG 0xC0011029
static void init_amd_ln(struct cpuinfo_x86 *c)
{
/*
* Apply erratum 665 fix unconditionally so machines without a BIOS
* fix work.
*/
msr_set_bit(MSR_AMD64_DE_CFG, 31);
}
static void init_amd_bd(struct cpuinfo_x86 *c)
{
u64 value;
......@@ -726,6 +737,7 @@ static void init_amd(struct cpuinfo_x86 *c)
case 6: init_amd_k7(c); break;
case 0xf: init_amd_k8(c); break;
case 0x10: init_amd_gh(c); break;
case 0x12: init_amd_ln(c); break;
case 0x15: init_amd_bd(c); break;
}
......
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