[PATCH 1/6] x86: Add support for the pcommit instruction

Ross Zwisler
2014-11-11T18:45:50Z

Add support for the new pcommit instruction. This instruction was
announced in the document "Intel Architecture Instruction Set Extensions
Programming Reference" with reference number 319433-022.

https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: H Peter Anvin <h.peter.anvin@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: x86@kernel.org
---
arch/x86/include/asm/cpufeature.h | 1 +
arch/x86/include/asm/special_insns.h | 6 ++++++
2 files changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 0bb1335..b3e6b89 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -225,6 +225,7 @@
#define X86_FEATURE_RDSEED ( 9*32+18) /* The RDSEED instruction */
#define X86_FEATURE_ADX ( 9*32+19) /* The ADCX and ADOX instructions */
#define X86_FEATURE_SMAP ( 9*32+20) /* Supervisor Mode Access Prevention */
+#define X86_FEATURE_PCOMMIT ( 9*32+22) /* PCOMMIT instruction */
#define X86_FEATURE_CLFLUSHOPT ( 9*32+23) /* CLFLUSHOPT instruction */
#define X86_FEATURE_AVX512PF ( 9*32+26) /* AVX-512 Prefetch */
#define X86_FEATURE_AVX512ER ( 9*32+27) /* AVX-512 Exponential and Reciprocal */
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index e820c08..1709a2e 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -199,6 +199,12 @@ static inline void clflushopt(volatile void *__p)
"+m" (*(volatile char __force *)__p));
}

+static inline void pcommit(void)
+{
+ alternative(ASM_NOP4, ".byte 0x66, 0x0f, 0xae, 0xf8",
+ X86_FEATURE_PCOMMIT);
+}
+
#define nop() asm volatile ("nop")

--
1.9.3