Merge branch 'x86/cpu' into perf/core, to pick up revert

perf/core has an earlier version of the x86/cpu tree merged, to avoid
conflicts, and due to this we want to pick up this ABI impacting
revert as well:

  049331f277fe: ("x86/fsgsbase: Revert FSGSBASE support")

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index f17c1a714779..8d6d92ebeb54 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -66,6 +66,32 @@ void check_mpx_erratum(struct cpuinfo_x86 *c)
         }
 }
 
+/*
+ * Processors which have self-snooping capability can handle conflicting
+ * memory type across CPUs by snooping its own cache. However, there exists
+ * CPU models in which having conflicting memory types still leads to
+ * unpredictable behavior, machine check errors, or hangs. Clear this
+ * feature to prevent its use on machines with known erratas.
+ */
+static void check_memory_type_self_snoop_errata(struct cpuinfo_x86 *c)
+{
+        switch (c->x86_model) {
+        case INTEL_FAM6_CORE_YONAH:
+        case INTEL_FAM6_CORE2_MEROM:
+        case INTEL_FAM6_CORE2_MEROM_L:
+        case INTEL_FAM6_CORE2_PENRYN:
+        case INTEL_FAM6_CORE2_DUNNINGTON:
+        case INTEL_FAM6_NEHALEM:
+        case INTEL_FAM6_NEHALEM_G:
+        case INTEL_FAM6_NEHALEM_EP:
+        case INTEL_FAM6_NEHALEM_EX:
+        case INTEL_FAM6_WESTMERE:
+        case INTEL_FAM6_WESTMERE_EP:
+        case INTEL_FAM6_SANDYBRIDGE:
+                setup_clear_cpu_cap(X86_FEATURE_SELFSNOOP);
+        }
+}
+
 static bool ring3mwait_disabled __read_mostly;
 
 static int __init ring3mwait_disable(char *__unused)
@@ -304,6 +330,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
         }
 
         check_mpx_erratum(c);
+        check_memory_type_self_snoop_errata(c);
 
         /*
          * Get the number of SMT siblings early from the extended topology