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authorAndi Kleen <ak@linux.intel.com>2011-10-12 17:46:33 -0700
committerIngo Molnar <mingo@elte.hu>2011-10-14 13:16:35 +0200
commit506ed6b53e00ba303ad778122f08e1fca7cf5efb (patch)
tree264fa332aa060c396caa89d41cbb6f7c5e7f4d3f /arch/x86/kernel/microcode_intel.c
parent70989449daccf545214b4840b112558e25c2b3fc (diff)
x86, intel: Output microcode revision in /proc/cpuinfo
I got a request to make it easier to determine the microcode update level on Intel CPUs. This patch adds a new "microcode" field to /proc/cpuinfo. The microcode level is also outputed on fatal machine checks together with the other CPUID model information. I removed the respective code from the microcode update driver, it just reads the field from cpu_data. Also when the microcode is updated it fills in the new values too. I had to add a memory barrier to native_cpuid to prevent it being optimized away when the result is not used. This turns out to clean up further code which already got this information manually. This is done in followon patches. Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/1318466795-7393-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/microcode_intel.c')
-rw-r--r--arch/x86/kernel/microcode_intel.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c
index 1a1b606d3e92..3ca42d0e43a2 100644
--- a/arch/x86/kernel/microcode_intel.c
+++ b/arch/x86/kernel/microcode_intel.c
@@ -161,12 +161,7 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
csig->pf = 1 << ((val[1] >> 18) & 7);
}
- wrmsr(MSR_IA32_UCODE_REV, 0, 0);
- /* see notes above for revision 1.07. Apparent chip bug */
- sync_core();
- /* get the current revision from MSR 0x8B */
- rdmsr(MSR_IA32_UCODE_REV, val[0], csig->rev);
-
+ csig->rev = c->microcode;
pr_info("CPU%d sig=0x%x, pf=0x%x, revision=0x%x\n",
cpu_num, csig->sig, csig->pf, csig->rev);
@@ -299,9 +294,9 @@ static int apply_microcode(int cpu)
struct microcode_intel *mc_intel;
struct ucode_cpu_info *uci;
unsigned int val[2];
- int cpu_num;
+ int cpu_num = raw_smp_processor_id();
+ struct cpuinfo_x86 *c = &cpu_data(cpu_num);
- cpu_num = raw_smp_processor_id();
uci = ucode_cpu_info + cpu;
mc_intel = uci->mc;
@@ -317,7 +312,7 @@ static int apply_microcode(int cpu)
(unsigned long) mc_intel->bits >> 16 >> 16);
wrmsr(MSR_IA32_UCODE_REV, 0, 0);
- /* see notes above for revision 1.07. Apparent chip bug */
+ /* As documented in the SDM: Do a CPUID 1 here */
sync_core();
/* get the current revision from MSR 0x8B */
@@ -335,6 +330,7 @@ static int apply_microcode(int cpu)
(mc_intel->hdr.date >> 16) & 0xff);
uci->cpu_sig.rev = val[1];
+ c->microcode = val[1];
return 0;
}