From: Matthew Wilcox <[email protected]> These are single instructions on x86. There's no 64-bit instruction for x86-32, but we don't yet have any user for memset64() on 32-bit architectures, so don't bother to implement it.
Signed-off-by: Matthew Wilcox <[email protected]> --- arch/x86/include/asm/string_32.h | 24 ++++++++++++++++++++++++ arch/x86/include/asm/string_64.h | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+) diff --git a/arch/x86/include/asm/string_32.h b/arch/x86/include/asm/string_32.h index e9ee84873de5..e371e7229042 100644 --- a/arch/x86/include/asm/string_32.h +++ b/arch/x86/include/asm/string_32.h @@ -340,6 +340,30 @@ extern void *memset(void *, int, size_t); #endif #endif /* !CONFIG_FORTIFY_SOURCE */ +#define __HAVE_ARCH_MEMSET16 +static inline void *memset16(uint16_t *s, uint16_t v, size_t n) +{ + int d0, d1; + asm volatile("rep\n\t" + "stosw" + : "=&c" (d0), "=&D" (d1) + : "a" (v), "1" (s), "0" (n) + : "memory"); + return s; +} + +#define __HAVE_ARCH_MEMSET32 +static inline void *memset32(uint32_t *s, uint32_t v, size_t n) +{ + int d0, d1; + asm volatile("rep\n\t" + "stosl" + : "=&c" (d0), "=&D" (d1) + : "a" (v), "1" (s), "0" (n) + : "memory"); + return s; +} + /* * find the first occurrence of byte 'c', or 1 past the area if none */ diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h index 2a8c822de1fc..f372a70a523f 100644 --- a/arch/x86/include/asm/string_64.h +++ b/arch/x86/include/asm/string_64.h @@ -58,6 +58,42 @@ extern void *__memcpy(void *to, const void *from, size_t len); void *memset(void *s, int c, size_t n); void *__memset(void *s, int c, size_t n); +#define __HAVE_ARCH_MEMSET16 +static inline void *memset16(uint16_t *s, uint16_t v, size_t n) +{ + long d0, d1; + asm volatile("rep\n\t" + "stosw" + : "=&c" (d0), "=&D" (d1) + : "a" (v), "1" (s), "0" (n) + : "memory"); + return s; +} + +#define __HAVE_ARCH_MEMSET32 +static inline void *memset32(uint32_t *s, uint32_t v, size_t n) +{ + long d0, d1; + asm volatile("rep\n\t" + "stosl" + : "=&c" (d0), "=&D" (d1) + : "a" (v), "1" (s), "0" (n) + : "memory"); + return s; +} + +#define __HAVE_ARCH_MEMSET64 +static inline void *memset64(uint64_t *s, uint64_t v, size_t n) +{ + long d0, d1; + asm volatile("rep\n\t" + "stosq" + : "=&c" (d0), "=&D" (d1) + : "a" (v), "1" (s), "0" (n) + : "memory"); + return s; +} + #define __HAVE_ARCH_MEMMOVE void *memmove(void *dest, const void *src, size_t count); void *__memmove(void *dest, const void *src, size_t count); -- 2.13.2
