From 61031952f4c89dba1065f7a5b9419badb112554c Mon Sep 17 00:00:00 2001 From: Ross Zwisler Date: Thu, 25 Jun 2015 03:08:39 -0400 Subject: arch, x86: pmem api for ensuring durability of persistent memory updates Based on an original patch by Ross Zwisler [1]. Writes to persistent memory have the potential to be posted to cpu cache, cpu write buffers, and platform write buffers (memory controller) before being committed to persistent media. Provide apis, memcpy_to_pmem(), wmb_pmem(), and memremap_pmem(), to write data to pmem and assert that it is durable in PMEM (a persistent linear address range). A '__pmem' attribute is added so sparse can track proper usage of pointers to pmem. This continues the status quo of pmem being x86 only for 4.2, but reworks to ioremap, and wider implementation of memremap() will enable other archs in 4.3. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-May/000932.html Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Signed-off-by: Ross Zwisler [djbw: various reworks] Signed-off-by: Dan Williams --- arch/x86/include/asm/io.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/include/asm/io.h') diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 34a5b93704d3..c60c3f3b0183 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -247,6 +247,12 @@ static inline void flush_write_buffers(void) #endif } +static inline void __pmem *arch_memremap_pmem(resource_size_t offset, + unsigned long size) +{ + return (void __force __pmem *) ioremap_cache(offset, size); +} + #endif /* __KERNEL__ */ extern void native_io_delay(void); -- cgit v1.2.3