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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-20 14:37:08 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-20 14:37:08 -0800 |
| commit | 8a9365a4725a4d6265a416dd63bff937e300308e (patch) | |
| tree | af92e88d6e8d976080674d411850695f48d0f261 /arch/x86/kernel/cpu/intel.c | |
| parent | 2891e8e66787a6a5dadad017d1c8a8f23d8658af (diff) | |
| parent | 3bba73b1b7a88d88c3ea16b7914c13d475e4a87b (diff) | |
Merge branch 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpufeature updates from Ingo Molnar:
"The main changes in this cycle were related to enable ring-3
MONITOR/MWAIT instructions support on supported CPUs, by Grzegorz
Andrejczuk and Piotr Luc"
* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpufeature: Move RING3MWAIT feature to avoid conflicts
x86/cpufeature: Enable RING3MWAIT for Knights Mill
x86/cpufeature: Enable RING3MWAIT for Knights Landing
x86/cpufeature: Add RING3MWAIT to CPU features
x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT
x86/msr: Add MSR_MISC_FEATURE_ENABLES and RING3MWAIT bit
x86/cpufeature: Add AVX512_VPOPCNTDQ feature
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 026c728d6ba7..017ecd3bb553 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -15,6 +15,8 @@ #include <asm/cpu.h> #include <asm/intel-family.h> #include <asm/microcode_intel.h> +#include <asm/hwcap2.h> +#include <asm/elf.h> #ifdef CONFIG_X86_64 #include <linux/topology.h> @@ -62,6 +64,46 @@ void check_mpx_erratum(struct cpuinfo_x86 *c) } } +static bool ring3mwait_disabled __read_mostly; + +static int __init ring3mwait_disable(char *__unused) +{ + ring3mwait_disabled = true; + return 0; +} +__setup("ring3mwait=disable", ring3mwait_disable); + +static void probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c) +{ + /* + * Ring 3 MONITOR/MWAIT feature cannot be detected without + * cpu model and family comparison. + */ + if (c->x86 != 6) + return; + switch (c->x86_model) { + case INTEL_FAM6_XEON_PHI_KNL: + case INTEL_FAM6_XEON_PHI_KNM: + break; + default: + return; + } + + if (ring3mwait_disabled) { + msr_clear_bit(MSR_MISC_FEATURE_ENABLES, + MSR_MISC_FEATURE_ENABLES_RING3MWAIT_BIT); + return; + } + + msr_set_bit(MSR_MISC_FEATURE_ENABLES, + MSR_MISC_FEATURE_ENABLES_RING3MWAIT_BIT); + + set_cpu_cap(c, X86_FEATURE_RING3MWAIT); + + if (c == &boot_cpu_data) + ELF_HWCAP2 |= HWCAP2_RING3MWAIT; +} + static void early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable; @@ -562,6 +604,8 @@ static void init_intel(struct cpuinfo_x86 *c) detect_vmx_virtcap(c); init_intel_energy_perf(c); + + probe_xeon_phi_r3mwait(c); } #ifdef CONFIG_X86_32 |