4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Borislav Petkov <[email protected]> commit f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 upstream CPUID Fn8000_0007_EDX[CPB] is wrongly 0 on models up to B1. But they do support CPB (AMD's Core Performance Boosting cpufreq CPU feature), so fix that. Signed-off-by: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sherry Hurwitz <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: David Woodhouse <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kernel/cpu/amd.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -749,6 +749,16 @@ static void init_amd_bd(struct cpuinfo_x } } +static void init_amd_zn(struct cpuinfo_x86 *c) +{ + /* + * 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) + set_cpu_cap(c, X86_FEATURE_CPB); +} + static void init_amd(struct cpuinfo_x86 *c) { u32 dummy; @@ -779,6 +789,7 @@ 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; } /* Enable workaround for FXSAVE leak */
