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authorJoe Korty <joe.korty@ccur.com>2009-03-19 13:27:44 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2009-03-23 15:00:04 -0700
commit55ec5cadc315fee6950e5a04d54694da3baf2f69 (patch)
tree356f7c6a418e59f4321760ec394e8fb8a2d35d27 /arch
parent32145abccae99820e3850acd458eb2a1934fb0e5 (diff)
Fix misreporting of #cores as #hyperthreads for Q9550
Fix misreporting of #cores for the Intel Quad Core Q9550. For the Q9550, in x86_64 mode, /proc/cpuinfo mistakenly reports the #cores present as the #hyperthreads present. i386 mode was not examined but is assumed to have the same problem. A backport of the following three 2.6.29-rc1 patches fixes the problem: 066941bd4eeb159307a5d7d795100d0887c00442: [PATCH] x86: unmask CPUID levels on Intel CPUs 99fb4d349db7e7dacb2099c5cc320a9e2d31c1ef: [PATCH] x86: unmask CPUID levels on Intel CPUs, fix bdf21a49bab28f0d9613e8d8724ef9c9168b61b9: [PATCH] x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h> From the first patch: "If the CPUID limit bit in MSR_IA32_MISC_ENABLE is set, clear it to make all CPUID information available. This is required for some features to work, in particular XSAVE." Originally-Developed-by: H. Peter Anvin <hpa@linux.intel.com> Backported-by: Joe Korty <joe.korty@ccur.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Joe Korty <joe.korty@ccur.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/intel.c13
-rw-r--r--arch/x86/kernel/cpu/intel_64.c13
2 files changed, 26 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index b75f2569b8f..31027aa5cbf 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -32,6 +32,19 @@ struct movsl_mask movsl_mask __read_mostly;
static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
+ /* Unmask CPUID levels if masked: */
+ if (c->x86 == 6 && c->x86_model >= 15) {
+ u64 misc_enable;
+
+ rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+
+ if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
+ misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
+ wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+ c->cpuid_level = cpuid_eax(0);
+ }
+ }
+
/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
if (c->x86 == 15 && c->x86_cache_alignment == 64)
c->x86_cache_alignment = 128;
diff --git a/arch/x86/kernel/cpu/intel_64.c b/arch/x86/kernel/cpu/intel_64.c
index 1019c58d39f..7ccd551afc7 100644
--- a/arch/x86/kernel/cpu/intel_64.c
+++ b/arch/x86/kernel/cpu/intel_64.c
@@ -9,6 +9,19 @@
static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
{
+ /* Unmask CPUID levels if masked: */
+ if (c->x86 == 6 && c->x86_model >= 15) {
+ u64 misc_enable;
+
+ rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+
+ if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) {
+ misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
+ wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
+ c->cpuid_level = cpuid_eax(0);
+ }
+ }
+
if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
(c->x86 == 0x6 && c->x86_model >= 0x0e))
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);