[PATCH 4.16 098/110] x86/cpufeatures: Add FEATURE_ZEN

From: Greg Kroah-Hartman
Date: Mon May 21 2018 - 16:36:08 EST


4.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

commit d1035d971829dcf80e8686ccde26f94b0a069472 upstream

Add a ZEN feature bit so family-dependent static_cpu_has() optimizations
can be built for ZEN.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/kernel/cpu/amd.c | 1 +
2 files changed, 2 insertions(+)

--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -218,6 +218,7 @@
#define X86_FEATURE_IBRS ( 7*32+25) /* Indirect Branch Restricted Speculation */
#define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */
#define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */

/* Virtualization flags: Linux defined, word 8 */
#define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -812,6 +812,7 @@ static void init_amd_bd(struct cpuinfo_x

static void init_amd_zn(struct cpuinfo_x86 *c)
{
+ set_cpu_cap(c, X86_FEATURE_ZEN);
/*
* Fix erratum 1076: CPB feature bit not being set in CPUID. It affects
* all up to and including B1.