From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 10 May 2018 16:26:00 +0200
Subject: x86/cpufeatures: Add FEATURE_ZEN
Git-commit: d1035d971829dcf80e8686ccde26f94b0a069472
Patch-mainline: v4.17-rc7
References: bsc#1087082 CVE-2018-3639

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

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/cpufeatures.h |    1 +
 arch/x86/kernel/cpu/amd.c          |    6 ++++++
 2 files changed, 7 insertions(+)

--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -220,6 +220,7 @@
 #define X86_FEATURE_IBRS		( 7*32+26) /* Indirect Branch Restricted Speculation */
 #define X86_FEATURE_IBPB		( 7*32+27) /* Indirect Branch Prediction Barrier */
 #define X86_FEATURE_STIBP		( 7*32+28) /* Single Thread Indirect Branch Predictors */
+#define X86_FEATURE_ZEN			( 7*32+29) /* "" 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
@@ -809,6 +809,11 @@ static void init_amd_bd(struct cpuinfo_x
 	}
 }
 
+static void init_amd_zn(struct cpuinfo_x86 *c)
+{
+	set_cpu_cap(c, X86_FEATURE_ZEN);
+}
+
 static void init_amd(struct cpuinfo_x86 *c)
 {
 	early_init_amd(c);
@@ -837,6 +842,7 @@ static void init_amd(struct cpuinfo_x86
 	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;
 	}
 
 	/*