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authorH. Peter Anvin <hpa@linux.intel.com>2013-04-19 16:36:03 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2013-04-19 16:36:03 -0700
commit74c3e3fcf350b2e7e3eaf9550528ee3f74e44b37 (patch)
tree60413af0bbe1fff8afdc35f36719e8150d78b7af
parent7eff7ded02d1b15ba8321664839b353fa6c0c1e4 (diff)
downloadlinux-74c3e3fcf350b2e7e3eaf9550528ee3f74e44b37.tar.gz
x86, microcode: Verify the family before dispatching microcode patching
For each CPU vendor that implements CPU microcode patching, there will be a minimum family for which this is implemented. Verify this minimum level of support. This can be done in the dispatch function or early in the application functions. Doing the latter turned out to be somewhat awkward because of the ineviable split between the BSP and the AP paths, and rather than pushing deep into the application functions, do this in the dispatch function. Reported-by: "Bryan O'Donoghue" <bryan.odonoghue.lkml@nexus-software.ie> Suggested-by: Borislav Petkov <bp@alien8.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1366392183-4149-1-git-send-email-bryan.odonoghue.lkml@nexus-software.ie
-rw-r--r--arch/x86/kernel/microcode_core_early.c38
1 files changed, 31 insertions, 7 deletions
diff --git a/arch/x86/kernel/microcode_core_early.c b/arch/x86/kernel/microcode_core_early.c
index 577db8417d1..833d51d6ee0 100644
--- a/arch/x86/kernel/microcode_core_early.c
+++ b/arch/x86/kernel/microcode_core_early.c
@@ -45,9 +45,6 @@ static int __cpuinit x86_vendor(void)
u32 eax = 0x00000000;
u32 ebx, ecx = 0, edx;
- if (!have_cpuid_p())
- return X86_VENDOR_UNKNOWN;
-
native_cpuid(&eax, &ebx, &ecx, &edx);
if (CPUID_IS(CPUID_INTEL1, CPUID_INTEL2, CPUID_INTEL3, ebx, ecx, edx))
@@ -59,18 +56,45 @@ static int __cpuinit x86_vendor(void)
return X86_VENDOR_UNKNOWN;
}
+static int __cpuinit x86_family(void)
+{
+ u32 eax = 0x00000001;
+ u32 ebx, ecx = 0, edx;
+ int x86;
+
+ native_cpuid(&eax, &ebx, &ecx, &edx);
+
+ x86 = (eax >> 8) & 0xf;
+ if (x86 == 15)
+ x86 += (eax >> 20) & 0xff;
+
+ return x86;
+}
+
void __init load_ucode_bsp(void)
{
- int vendor = x86_vendor();
+ int vendor, x86;
+
+ if (!have_cpuid_p())
+ return;
- if (vendor == X86_VENDOR_INTEL)
+ vendor = x86_vendor();
+ x86 = x86_family();
+
+ if (vendor == X86_VENDOR_INTEL && x86 >= 6)
load_ucode_intel_bsp();
}
void __cpuinit load_ucode_ap(void)
{
- int vendor = x86_vendor();
+ int vendor, x86;
+
+ if (!have_cpuid_p())
+ return;
+
+ vendor = x86_vendor();
+ x86 = x86_family();
- if (vendor == X86_VENDOR_INTEL)
+ if (vendor == X86_VENDOR_INTEL && x86 >= 6)
load_ucode_intel_ap();
}