Instead of blacklisting all Broadwell processorsi for running a late
loading, only BDW-EP (signature 406f1) with the microcode version
less than 0x0b000021 needs to be blacklisted.
This is documented in the the public documentation #334165 (See the
item BDF90 for details).
Signed-off-by: Jia Zhang <qianyue...@alibaba-inc.com>
---
arch/x86/kernel/cpu/microcode/intel.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/intel.c
b/arch/x86/kernel/cpu/microcode/intel.c
index 8ccdca6..d2c1638 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -910,8 +910,15 @@ 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 reault 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 < 0x0b000021U) {
+ pr_err_once("late loading on model 79 (sig 64f1) is
disabled.\n");
return true;
}
--
1.8.3.1
