From 506ed6b53e00ba303ad778122f08e1fca7cf5efb Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 12 Oct 2011 17:46:33 -0700 Subject: 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 Acked-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1318466795-7393-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/x86/kernel/cpu/intel.c') diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index ed6086eedf1d..26627a3a7148 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -47,6 +47,15 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) { + unsigned lower_word; + + wrmsr(MSR_IA32_UCODE_REV, 0, 0); + /* Required by the SDM */ + sync_core(); + rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode); + } + /* * Atom erratum AAE44/AAF40/AAG38/AAH41: * -- cgit v1.2.3 From 30963c0ac721f70aea0352ed1cd0fc3cfbaef730 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 12 Oct 2011 17:46:34 -0700 Subject: x86, intel: Use c->microcode for Atom errata check Now that the cpu update level is available the Atom PSE errata check can use it directly without reading the MSR again. Signed-off-by: Andi Kleen Acked-by: H. Peter Anvin Link: http://lkml.kernel.org/r/1318466795-7393-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/intel.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'arch/x86/kernel/cpu/intel.c') diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 26627a3a7148..523131213f08 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -64,17 +64,10 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) * need the microcode to have already been loaded... so if it is * not, recommend a BIOS update and disable large pages. */ - if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2) { - u32 ucode, junk; - - wrmsr(MSR_IA32_UCODE_REV, 0, 0); - sync_core(); - rdmsr(MSR_IA32_UCODE_REV, junk, ucode); - - if (ucode < 0x20e) { - printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n"); - clear_cpu_cap(c, X86_FEATURE_PSE); - } + if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 && + c->microcode < 0x20e) { + printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n"); + clear_cpu_cap(c, X86_FEATURE_PSE); } #ifdef CONFIG_X86_64 -- cgit v1.2.3