Messages in this thread Patch in this message | | | From | Borislav Petkov <> | Subject | [PATCH 3/3] x86/cpu: Add CLZERO detection | Date | Fri, 30 Oct 2015 13:11:39 +0100 |
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From: Wan Zongshun <Vincent.Wan@amd.com>
AMD Fam17h processors introduce support for the CLZERO instruction. It zeroes out the 64 byte cache line specified in RAX.
Add the bit here to allow /proc/cpuinfo to list the feature.
Boris: we're adding this as a separate ->x86_capability leaf because CPUID_80000008_EBX is going to contain more feature bits and it will fill out with time.
Signed-off-by: Wan Zongshun <Vincent.Wan@amd.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/1446059010-28010-3-git-send-email-Aravind.Gopalakrishnan@amd.com [Wrap code in patch form, fix comments. ] Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> --- arch/x86/include/asm/cpufeature.h | 5 ++++- arch/x86/kernel/cpu/common.c | 1 + 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 9727b3b48bd1..e4f8010f22e0 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -12,7 +12,7 @@ #include <asm/disabled-features.h> #endif -#define NCAPINTS 13 /* N 32-bit words worth of info */ +#define NCAPINTS 14 /* N 32-bit words worth of info */ #define NBUGINTS 1 /* N 32-bit bug flags */ /* @@ -255,6 +255,9 @@ /* Intel-defined CPU QoS Sub-leaf, CPUID level 0x0000000F:1 (edx), word 12 */ #define X86_FEATURE_CQM_OCCUP_LLC (12*32+ 0) /* LLC occupancy monitoring if 1 */ +/* AMD-defined CPU features, CPUID level 0x80000008 (ebx), word 13 */ +#define X86_FEATURE_CLZERO (13*32+0) /* CLZERO instruction */ + /* * BUG word(s) */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index de22ea7ff82f..4ddd780aeac9 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -670,6 +670,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c) c->x86_virt_bits = (eax >> 8) & 0xff; c->x86_phys_bits = eax & 0xff; + c->x86_capability[13] = cpuid_ebx(0x80000008); } #ifdef CONFIG_X86_32 else if (cpu_has(c, X86_FEATURE_PAE) || cpu_has(c, X86_FEATURE_PSE36)) -- 2.3.5
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