Some Zhaoxin CPUs declare support SSE4.2 instruction sets but having a CRC32C instruction implementation that not working as intended. Set low performance CRC32C flag on these CPUs for later use. Signed-off-by: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx> --- arch/x86/kernel/cpu/centaur.c | 7 +++++++ arch/x86/kernel/cpu/zhaoxin.c | 6 ++++++ 2 files changed, 13 insertions(+) diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c index 345f7d9..13e6fbe 100644 --- a/arch/x86/kernel/cpu/centaur.c +++ b/arch/x86/kernel/cpu/centaur.c @@ -109,6 +109,13 @@ static void early_init_centaur(struct cpuinfo_x86 *c) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); } + + /* + * These CPUs declare support SSE4.2 instruction sets but + * having low performance CRC32C instruction implementation. + */ + if (c->x86 == 0x6 || (c->x86 == 0x7 && c->x86_model <= 0x3b)) + set_cpu_cap(c, X86_FEATURE_CRC32C); } static void init_centaur(struct cpuinfo_x86 *c) diff --git a/arch/x86/kernel/cpu/zhaoxin.c b/arch/x86/kernel/cpu/zhaoxin.c index 05fa4ef..837ec65 100644 --- a/arch/x86/kernel/cpu/zhaoxin.c +++ b/arch/x86/kernel/cpu/zhaoxin.c @@ -79,6 +79,12 @@ static void early_init_zhaoxin(struct cpuinfo_x86 *c) c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff); } + /* + * These CPUs declare support SSE4.2 instruction sets but + * having low performance CRC32C instruction implementation. + */ + if (c->x86 == 0x6 || (c->x86 == 0x7 && c->x86_model <= 0x3b)) + set_cpu_cap(c, X86_FEATURE_CRC32C); } static void init_zhaoxin(struct cpuinfo_x86 *c) -- 2.7.4
