From ff24d867b9dea6b4e9c40bf5a0bddf1c6d60fbb8 Mon Sep 17 00:00:00 2001
From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Tue, 20 Nov 2018 11:00:18 +0800
Subject: [PATCH] x86/CPU/AMD: Set the CPB bit unconditionally on F17h

commit 0237199186e7a4aa5310741f0a6498a20c820fd7 upstream.

Some F17h models do not have CPB set in CPUID even though the CPU
supports it. Set the feature bit unconditionally on all F17h.

 [ bp: Rewrite commit message and patch. ]

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20181120030018.5185-1-jiaxun.yang@flygoat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kernel/cpu/amd.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 4c2648b96c9a..be6d0543e626 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -765,11 +765,9 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
 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.
-	 */
-	if (c->x86_model <= 1 && c->x86_stepping <= 1)
+
+	/* Fix erratum 1076: CPB feature bit not being set in CPUID. */
+	if (!cpu_has(c, X86_FEATURE_CPB))
 		set_cpu_cap(c, X86_FEATURE_CPB);
 }