在 2017/12/28 下午8:24, Ingo Molnar 写道: > > * Jia Zhang <[email protected]> wrote: > >> Instead of blacklisting all types of Broadwell processor when running >> a late loading, only BDW-EP (signature 0x406f1, aka family 6, model 79, >> stepping 1) with the microcode version less than 0x0b000021 needs to >> be blacklisted. >> >> The erratum is documented in the the public documentation #334165 (See >> the item BDF90 for details). >> >> Signed-off-by: Jia Zhang <[email protected]> >> --- >> arch/x86/kernel/cpu/microcode/intel.c | 12 ++++++++++-- >> 1 file changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kernel/cpu/microcode/intel.c >> b/arch/x86/kernel/cpu/microcode/intel.c >> index 8ccdca6..79cad85 100644 >> --- a/arch/x86/kernel/cpu/microcode/intel.c >> +++ b/arch/x86/kernel/cpu/microcode/intel.c >> @@ -910,8 +910,16 @@ static bool is_blacklisted(unsigned int cpu) >> { >> struct cpuinfo_x86 *c = &cpu_data(cpu); >> >> - if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X) { >> - pr_err_once("late loading on model 79 is disabled.\n"); >> + /* >> + * The Broadwell-EP processor with the microcode version less >> + * then 0x0b000021 may result in system hang when running a late >> + * loading. This behavior is documented in item BDF90, #334165 >> + * (Intel Xeon Processor E7-8800/4800 v4 Product Family). >> + */ >> + if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X && >> + c->x86_mask == 0x01 && c->microcode < 0x0b000021) { >> + pr_err_once("late loading on cpu (sig 0x406f1) is disabled " >> + "due to erratum causing system hang.\n"); > > Please never break user-readable messages mid-sentence! > > This should be something like: > > pr_err_once("Late loading of the CPU microcode (sig 0x406f1) is > disabled due to Intel erratum BDF90 causing system hangs.\n"); > > (note the spelling and readability improvements as well) > > Btw., what does 'sig 0x406f1' refer to?
It is so-called processor signature which can be used to identify a model of x86 processor uniquely. It's the return value of cpuid instruction with leaf 1(eax == 1). Jia > > Thanks, > > > Ingo >
