From fd1d961dd681d58308456049a817cbf4c0662018 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 2 Jun 2016 11:06:13 -0700 Subject: x86/insn: remove pcommit The pcommit instruction is being deprecated in favor of either ADR (asynchronous DRAM refresh: flush-on-power-fail) at the platform level, or posted-write-queue flush addresses as defined by the ACPI 6.x NFIT (NVDIMM Firmware Interface Table). Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Borislav Petkov Cc: Andy Lutomirski Cc: Xiao Guangrong Cc: Adrian Hunter Cc: Ross Zwisler Acked-by: Ingo Molnar Signed-off-by: Dan Williams --- arch/x86/include/asm/cpufeatures.h | 1 - arch/x86/include/asm/special_insns.h | 46 ------------------------------------ 2 files changed, 47 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 4a413485f9eb..700d97df7d28 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -225,7 +225,6 @@ #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_CLWB ( 9*32+24) /* CLWB instruction */ #define X86_FEATURE_AVX512PF ( 9*32+26) /* AVX-512 Prefetch */ diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index d96d04377765..587d7914ea4b 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -253,52 +253,6 @@ static inline void clwb(volatile void *__p) : [pax] "a" (p)); } -/** - * pcommit_sfence() - persistent commit and fence - * - * The PCOMMIT instruction ensures that data that has been flushed from the - * processor's cache hierarchy with CLWB, CLFLUSHOPT or CLFLUSH is accepted to - * memory and is durable on the DIMM. The primary use case for this is - * persistent memory. - * - * This function shows how to properly use CLWB/CLFLUSHOPT/CLFLUSH and PCOMMIT - * with appropriate fencing. - * - * Example: - * void flush_and_commit_buffer(void *vaddr, unsigned int size) - * { - * unsigned long clflush_mask = boot_cpu_data.x86_clflush_size - 1; - * void *vend = vaddr + size; - * void *p; - * - * for (p = (void *)((unsigned long)vaddr & ~clflush_mask); - * p < vend; p += boot_cpu_data.x86_clflush_size) - * clwb(p); - * - * // SFENCE to order CLWB/CLFLUSHOPT/CLFLUSH cache flushes - * // MFENCE via mb() also works - * wmb(); - * - * // PCOMMIT and the required SFENCE for ordering - * pcommit_sfence(); - * } - * - * After this function completes the data pointed to by 'vaddr' has been - * accepted to memory and will be durable if the 'vaddr' points to persistent - * memory. - * - * PCOMMIT must always be ordered by an MFENCE or SFENCE, so to help simplify - * things we include both the PCOMMIT and the required SFENCE in the - * alternatives generated by pcommit_sfence(). - */ -static inline void pcommit_sfence(void) -{ - alternative(ASM_NOP7, - ".byte 0x66, 0x0f, 0xae, 0xf8\n\t" /* pcommit */ - "sfence", - X86_FEATURE_PCOMMIT); -} - #define nop() asm volatile ("nop") -- cgit v1.2.3