These patches enable Intel Xeon Phi x200 feature to use MONITOR/MWAIT instruction in ring 3 (userspace) Patches set MSR 0x140 for all logical CPUs. Then expose it as CPU feature and introduces elf HWCAP capability for x86. Reference (the solution is temporary MSR definition will be in next SDM document): https://software.intel.com/en-us/blogs/2016/10/06/intel-xeon-phi-product-family-x200-knl-user-mode-ring-3-monitor-and-mwait
v2: Check MSR before wrmsrl Shortened names Used Word 3 for feature init_scattered_cpuid_features() Fixed commit messages v3: Included Daves and Thomas comments v4: Wrapped the enabling code by CONFIG_X86_64 Add documentation for phir3mwait=disable cmdline switch Move probe_ function call from early_intel_init to intel_init Fixed commit messages Grzegorz Andrejczuk (4): x86/phi: Add R3MWAIT register and bit to msr-info.h x86/phi: Add enabling of the R3MWAIT during boot x86: Use HWCAP2 to expoose Xeon Phi ring 3 MWAIT x86/phi: Add R3MWAIT to CPU features Documentation/kernel-parameters.txt | 5 +++++ arch/x86/include/asm/cpufeatures.h | 2 ++ arch/x86/include/asm/elf.h | 9 +++++++++ arch/x86/include/asm/msr-index.h | 5 +++++ arch/x86/include/uapi/asm/hwcap2.h | 7 +++++++ arch/x86/kernel/cpu/common.c | 3 +++ arch/x86/kernel/cpu/intel.c | 40 +++++++++++++++++++++++++++++++++++++ 7 files changed, 71 insertions(+) create mode 100644 arch/x86/include/uapi/asm/hwcap2.h -- 2.5.1
