[PATCH 1/2] x86, cpu: After uncapping CPUID, re-run CPU feature detection

Colin King colin.king at canonical.com
Wed Oct 6 14:46:04 UTC 2010


From: H. Peter Anvin <hpa at linux.intel.com>

BugLink: http://bugs.launchpad.net/bugs/615153

After uncapping the CPUID level, we need to also re-run the CPU
feature detection code.

This resolves kernel bugzilla 16322.

Reported-by: boris64 <bugzilla.kernel.org at boris64.net>
Cc: <stable at kernel.org> v2.6.29..2.6.35
LKML-Reference: <tip- at git.kernel.org>
Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 arch/x86/kernel/cpu/common.c |    2 +-
 arch/x86/kernel/cpu/cpu.h    |    1 +
 arch/x86/kernel/cpu/intel.c  |    1 +
 3 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4ff2597..8962fc7 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -537,7 +537,7 @@ void __cpuinit cpu_detect(struct cpuinfo_x86 *c)
 	}
 }
 
-static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
+void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
 {
 	u32 tfms, xlvl;
 	u32 ebx;
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index 3624e8a..f668bb1 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -33,5 +33,6 @@ extern const struct cpu_dev *const __x86_cpu_dev_start[],
 			    *const __x86_cpu_dev_end[];
 
 extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
+extern void get_cpu_cap(struct cpuinfo_x86 *c);
 
 #endif
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 85f69cd..b438944 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -39,6 +39,7 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
 			misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID;
 			wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable);
 			c->cpuid_level = cpuid_eax(0);
+			get_cpu_cap(c);
 		}
 	}
 
-- 
1.7.0.4





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