[PATCH v2 0/4] Enabling Ring 3 MONITOR/MWAIT feature for Knights Landing

From: Grzegorz Andrejczuk
Date: Wed Oct 12 2016 - 08:16:45 EST


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:
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

Grzegorz Andrejczuk (4):
Add R3MWAIT register and bit to msr-info.h
Add enabling of the R3 MWAIT during boot for KNL
Add hwcap2 for x86
Add R3MWAIT to CPU features

arch/x86/include/asm/cpufeatures.h | 2 ++
arch/x86/include/asm/elf.h | 7 +++++++
arch/x86/include/asm/msr-index.h | 5 +++++
arch/x86/include/uapi/asm/hwcap.h | 7 +++++++
arch/x86/kernel/cpu/common.c | 6 ++++++
arch/x86/kernel/cpu/intel.c | 27 +++++++++++++++++++++++++++
arch/x86/kernel/cpu/scattered.c | 5 +++++
7 files changed, 59 insertions(+)
create mode 100644 arch/x86/include/uapi/asm/hwcap.h

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2.5.1