diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/cacheflush.h | 72 | ||||
| -rw-r--r-- | arch/x86/include/asm/io.h | 6 |
3 files changed, 79 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1a2cbf641667..62564ddf7f78 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -27,6 +27,7 @@ config X86 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS select ARCH_HAS_FAST_MULTIPLIER select ARCH_HAS_GCOV_PROFILE_ALL + select ARCH_HAS_PMEM_API select ARCH_MIGHT_HAVE_PC_PARPORT select ARCH_MIGHT_HAVE_PC_SERIO select HAVE_AOUT if X86_32 diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index 47c8e32f621a..ec23bb753a3e 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -4,6 +4,7 @@ /* Caches aren't brain-dead on the intel. */ #include <asm-generic/cacheflush.h> #include <asm/special_insns.h> +#include <asm/uaccess.h> /* * The set_memory_* API can be used to change various attributes of a virtual @@ -104,4 +105,75 @@ static inline int rodata_test(void) } #endif +#ifdef ARCH_HAS_NOCACHE_UACCESS + +/** + * arch_memcpy_to_pmem - copy data to persistent memory + * @dst: destination buffer for the copy + * @src: source buffer for the copy + * @n: length of the copy in bytes + * + * Copy data to persistent memory media via non-temporal stores so that + * a subsequent arch_wmb_pmem() can flush cpu and memory controller + * write buffers to guarantee durability. + */ +static inline void arch_memcpy_to_pmem(void __pmem *dst, const void *src, + size_t n) +{ + int unwritten; + + /* + * We are copying between two kernel buffers, if + * __copy_from_user_inatomic_nocache() returns an error (page + * fault) we would have already reported a general protection fault + * before the WARN+BUG. + */ + unwritten = __copy_from_user_inatomic_nocache((void __force *) dst, + (void __user *) src, n); + if (WARN(unwritten, "%s: fault copying %p <- %p unwritten: %d\n", + __func__, dst, src, unwritten)) + BUG(); +} + +/** + * arch_wmb_pmem - synchronize writes to persistent memory + * + * After a series of arch_memcpy_to_pmem() operations this drains data + * from cpu write buffers and any platform (memory controller) buffers + * to ensure that written data is durable on persistent memory media. + */ +static inline void arch_wmb_pmem(void) +{ + /* + * wmb() to 'sfence' all previous writes such that they are + * architecturally visible to 'pcommit'. Note, that we've + * already arranged for pmem writes to avoid the cache via + * arch_memcpy_to_pmem(). + */ + wmb(); + pcommit_sfence(); +} + +static inline bool __arch_has_wmb_pmem(void) +{ +#ifdef CONFIG_X86_64 + /* + * We require that wmb() be an 'sfence', that is only guaranteed on + * 64-bit builds + */ + return static_cpu_has(X86_FEATURE_PCOMMIT); +#else + return false; +#endif +} +#else /* ARCH_HAS_NOCACHE_UACCESS i.e. ARCH=um */ +extern void arch_memcpy_to_pmem(void __pmem *dst, const void *src, size_t n); +extern void arch_wmb_pmem(void); + +static inline bool __arch_has_wmb_pmem(void) +{ + return false; +} +#endif + #endif /* _ASM_X86_CACHEFLUSH_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); |