[PATCH 5.0 29/46] x86/CPU/AMD: Set the CPB bit unconditionally on F17h

Greg Kroah-Hartman
2019-03-08T12:52:09Z

From: Jiaxun Yang <jiaxun.yang@flygoat.com>

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(-)

--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -819,11 +819,9 @@ 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.
- */
- 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);
}