x86/CPU/AMD: Set the CPB bit unconditionally on F17h

FlyGoat · suryasaimadhu · commit 0237199186e7 · 2019-01-18T16:44:03.000+01:00
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
diff --git 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_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);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -819,11 +819,9 @@ static void init_amd_bd(struct cpuinfo_x86 *c)`
`819`	`819`	`static void init_amd_zn(struct cpuinfo_x86 *c)`
`820`	`820`	`{`
`821`	`821`	`set_cpu_cap(c, X86_FEATURE_ZEN);`
`822`		`- /*`
`823`		`- * Fix erratum 1076: CPB feature bit not being set in CPUID. It affects`
`824`		`- * all up to and including B1.`
`825`		`- */`
`826`		`- if (c->x86_model <= 1 && c->x86_stepping <= 1)`
	`822`	`+`
	`823`	`+ /* Fix erratum 1076: CPB feature bit not being set in CPUID. */`
	`824`	`+ if (!cpu_has(c, X86_FEATURE_CPB))`
`827`	`825`	`set_cpu_cap(c, X86_FEATURE_CPB);`
`828`	`826`	`}`
`829`	`827`