summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/cpu/intel.c
diff options
context:
space:
mode:
authorPeter Zijlstra <peterz@infradead.org>2016-07-18 11:41:10 -0700
committerIngo Molnar <mingo@kernel.org>2016-07-20 09:48:40 +0200
commit08e237fa56a1d95c1372033bc29c4a2517b3c0fa (patch)
tree516f04cfcd11fafd8d801c7ce0ed60ca660d26d0 /arch/x86/kernel/cpu/intel.c
parent4fffe71dd913cca5532da594e2f48a0db6b494dc (diff)
x86/cpu: Add workaround for MONITOR instruction erratum on Goldmont based CPUs
Monitored cached line may not wake up from mwait on certain Goldmont based CPUs. This patch will avoid calling current_set_polling_and_test() and thereby not set the TIF_ flag. The result is that we'll always send IPIs for wakeups. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1468867270-18493-1-git-send-email-jacob.jun.pan@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index c1a89bc026ac..abf601235b29 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -13,6 +13,7 @@
#include <asm/msr.h>
#include <asm/bugs.h>
#include <asm/cpu.h>
+#include <asm/intel-family.h>
#ifdef CONFIG_X86_64
#include <linux/topology.h>
@@ -508,6 +509,10 @@ static void init_intel(struct cpuinfo_x86 *c)
(c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);
+ if (c->x86 == 6 && boot_cpu_has(X86_FEATURE_MWAIT) &&
+ ((c->x86_model == INTEL_FAM6_ATOM_GOLDMONT)))
+ set_cpu_bug(c, X86_BUG_MONITOR);
+
#ifdef CONFIG_X86_64
if (c->x86 == 15)
c->x86_cache_alignment = c->x86_clflush_size * 2;