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x86, amd: Restrict usage of c1e_idle() 

Currently c1e_idle returns true for all CPUs greater than or equal to
family 0xf model 0x40. This covers too many CPUs.

Meanwhile a respective erratum for the underlying problem was filed
(#400). This patch adds the logic to check whether erratum #400
applies to a given CPU.
Especially for CPUs where SMI/HW triggered C1e is not supported,
c1e_idle() doesn't need to be used. We can check this by looking at
the respective OSVW bit for erratum #400.

Cc: <stable@kernel.org> # .32.x .33.x
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100319110922.GA19614@alberich.amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Andreas Herrmann 2010-03-19 12:09:22 +01:00 committed by H. Peter Anvin
parent ff30a0543e
commit 035a02c1e1
2 changed files with 26 additions and 8 deletions
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2
arch/x86/include/asm/msr-index.h
View File

@ -105,6 +105,8 @@
#define MSR_AMD64_PATCH_LEVEL 0x0000008b
#define MSR_AMD64_NB_CFG 0xc001001f
#define MSR_AMD64_PATCH_LOADER 0xc0010020
#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140
#define MSR_AMD64_OSVW_STATUS 0xc0010141
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
#define MSR_AMD64_IBSFETCHLINAD 0xc0011031
#define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032

32
arch/x86/kernel/process.c
View File

@ -526,21 +526,37 @@ static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
}
/*
* Check for AMD CPUs, which have potentially C1E support
* Check for AMD CPUs, where APIC timer interrupt does not wake up CPU from C1e.
* For more information see
* - Erratum #400 for NPT family 0xf and family 0x10 CPUs
* - Erratum #365 for family 0x11 (not affected because C1e not in use)
*/
static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c)
{
u64 val;
if (c->x86_vendor != X86_VENDOR_AMD)
return 0;
if (c->x86 < 0x0F)
return 0;
goto no_c1e_idle;
/* Family 0x0f models < rev F do not have C1E */
if (c->x86 == 0x0f && c->x86_model < 0x40)
return 0;
if (c->x86 == 0x0F && c->x86_model >= 0x40)
return 1;
return 1;
if (c->x86 == 0x10) {
/*
* check OSVW bit for CPUs that are not affected
* by erratum #400
*/
rdmsrl(MSR_AMD64_OSVW_ID_LENGTH, val);
if (val >= 2) {
rdmsrl(MSR_AMD64_OSVW_STATUS, val);
if (!(val & BIT(1)))
goto no_c1e_idle;
}
return 1;
}
no_c1e_idle:
return 0;
}
static cpumask_var_t c1e_mask;