[GIT pull] x86 fix for 4.14

From: Thomas Gleixner
Date: Sun Sep 17 2017 - 05:30:23 EST


Linus,

please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

A single fix addressing the missing CP8 feature bit in CPUID for a range of
AMD ZEN models/mask revisions.

Thanks,

tglx

------------------>
Borislav Petkov (1):
x86/cpu/AMD: Fix erratum 1076 (CPB bit)


arch/x86/kernel/cpu/amd.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9862e2cd6d93..d58184b7cd44 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -763,6 +763,16 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
}
}

+static void init_amd_zn(struct cpuinfo_x86 *c)
+{
+ /*
+ * Fix erratum 1076: CPB feature bit not being set in CPUID. It affects
+ * all up to and including B1.
+ */
+ if (c->x86_model <= 1 && c->x86_mask <= 1)
+ set_cpu_cap(c, X86_FEATURE_CPB);
+}
+
static void init_amd(struct cpuinfo_x86 *c)
{
early_init_amd(c);
@@ -791,6 +801,7 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x10: init_amd_gh(c); break;
case 0x12: init_amd_ln(c); break;
case 0x15: init_amd_bd(c); break;
+ case 0x17: init_amd_zn(c); break;
}

/* Enable workaround for FXSAVE leak */