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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-22 19:23:53 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-22 19:23:53 +0400 |
| commit | 358c323c17ac527b82c6333db6a485112c21ab0d (patch) | |
| tree | ef9569266eabfa0ffb435a8bf03088fe9e82c0b2 /arch/x86/kernel/cpu/addon_cpuid_features.c | |
| parent | a7b354e868bc2f887dfb0a418aa7d96df1afc399 (diff) | |
| parent | 9754a5b840a209bc1f192d59f63e81b698a55ac8 (diff) | |
| download | linux-358c323c17ac527b82c6333db6a485112c21ab0d.tar.xz | |
Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: work around MTRR mask setting, v2
x86: fix section mismatch warning - uv_cpu_init
x86: fix VMI for early params
x86: fix two modpost warnings in mm/init_64.c
x86: fix 1:1 mapping init on 64-bit (memory hotplug case)
x86: work around MTRR mask setting
x86: PAT Update validate_pat_support for intel CPUs
devmem, x86: PAT Change /dev/mem mmap with O_SYNC to use UC_MINUS
x86: PAT proper tracking of set_memory_uc and friends
x86: fix BUG: unable to handle kernel paging request (numaq_tsc_disable)
x86: export pv_lock_ops non-GPL
x86, mmiotrace: silence section mismatch warning - leave_uniprocessor
x86: use WARN() in arch/x86/kernel
x86: use WARN() in arch/x86/mm/ioremap.c
werror: fix pci calgary
x86: fix oprofile + hibernation badness
x86, SGI UV: hardcode the TLB flush interrupt system vector
x86: fix Xorg startup/shutdown slowdown with PAT
x86: fix "kernel won't boot on a Cyrix MediaGXm (Geode)"
x86 iommu: remove unneeded parenthesis
Diffstat (limited to 'arch/x86/kernel/cpu/addon_cpuid_features.c')
| -rw-r--r-- | arch/x86/kernel/cpu/addon_cpuid_features.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/addon_cpuid_features.c b/arch/x86/kernel/cpu/addon_cpuid_features.c index 84a8220a6072..a6ef672adbba 100644 --- a/arch/x86/kernel/cpu/addon_cpuid_features.c +++ b/arch/x86/kernel/cpu/addon_cpuid_features.c @@ -56,9 +56,22 @@ void __cpuinit validate_pat_support(struct cpuinfo_x86 *c) switch (c->x86_vendor) { case X86_VENDOR_INTEL: - if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15)) + /* + * There is a known erratum on Pentium III and Core Solo + * and Core Duo CPUs. + * " Page with PAT set to WC while associated MTRR is UC + * may consolidate to UC " + * Because of this erratum, it is better to stick with + * setting WC in MTRR rather than using PAT on these CPUs. + * + * Enable PAT WC only on P4, Core 2 or later CPUs. + */ + if (c->x86 > 0x6 || (c->x86 == 6 && c->x86_model >= 15)) return; - break; + + pat_disable("PAT WC disabled due to known CPU erratum."); + return; + case X86_VENDOR_AMD: case X86_VENDOR_CENTAUR: case X86_VENDOR_TRANSMETA: |