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| author |   Kyung Min Park <kyung.min.park@intel.com> | 2020-04-24 12:37:56 -0700 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2020-05-07 16:06:20 +0200 |
| commit | cec5f268cd02d25d2d74807843d8ae0292fe0fb7 (patch) | |
| tree | 917947f6e242b5f1c21e136cf3916dd09c3473ce /arch/x86/Kconfig.assembler | |
| parent | x86/delay: Refactor delay_mwaitx() for TPAUSE support (diff) | |
| download | linux-dev-cec5f268cd02d25d2d74807843d8ae0292fe0fb7.tar.xz linux-dev-cec5f268cd02d25d2d74807843d8ae0292fe0fb7.zip | |
x86/delay: Introduce TPAUSE delay
TPAUSE instructs the processor to enter an implementation-dependent
optimized state. The instruction execution wakes up when the time-stamp
counter reaches or exceeds the implicit EDX:EAX 64-bit input value.
The instruction execution also wakes up due to the expiration of
the operating system time-limit or by an external interrupt
or exceptions such as a debug exception or a machine check exception.
TPAUSE offers a choice of two lower power states:
1. Light-weight power/performance optimized state C0.1
2. Improved power/performance optimized state C0.2
This way, it can save power with low wake-up latency in comparison to
spinloop based delay. The selection between the two is governed by the
input register.
TPAUSE is available on processors with X86_FEATURE_WAITPKG.
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1587757076-30337-4-git-send-email-kyung.min.park@intel.com
Diffstat (limited to 'arch/x86/Kconfig.assembler')
| -rw-r--r-- | arch/x86/Kconfig.assembler | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/Kconfig.assembler b/arch/x86/Kconfig.assembler index 13de0db38d4e..26b8c08e2fc4 100644 --- a/arch/x86/Kconfig.assembler +++ b/arch/x86/Kconfig.assembler @@ -15,3 +15,7 @@ config AS_SHA256_NI def_bool $(as-instr,sha256msg1 %xmm0$(comma)%xmm1) help Supported by binutils >= 2.24 and LLVM integrated assembler +config AS_TPAUSE + def_bool $(as-instr,tpause %ecx) + help + Supported by binutils >= 2.31.1 and LLVM integrated assembler >= V7 |