diff options
Diffstat (limited to 'arch/x86/include/asm/special_insns.h')
| -rw-r--r-- | arch/x86/include/asm/special_insns.h | 46 |
1 files changed, 0 insertions, 46 deletions
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") |