From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Subject: x86: implement memset16, memset32 & memset64 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. Link: http://lkml.kernel.org/r/20170720184539.31609-4-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxxxx> Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx> Cc: David Miller <davem@xxxxxxxxxxxxx> Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx> Cc: Matt Turner <mattst88@xxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Richard Henderson <rth@xxxxxxxxxxx> Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/string_32.h | 24 +++++++++++++++++++ arch/x86/include/asm/string_64.h | 36 +++++++++++++++++++++++++++++ 2 files changed, 60 insertions(+) diff -puN arch/x86/include/asm/string_32.h~x86-implement-memset16-memset32-memset64 arch/x86/include/asm/string_32.h --- a/arch/x86/include/asm/string_32.h~x86-implement-memset16-memset32-memset64 +++ a/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 -puN arch/x86/include/asm/string_64.h~x86-implement-memset16-memset32-memset64 arch/x86/include/asm/string_64.h --- a/arch/x86/include/asm/string_64.h~x86-implement-memset16-memset32-memset64 +++ a/arch/x86/include/asm/string_64.h @@ -58,6 +58,42 @@ extern void *__memcpy(void *to, const vo 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); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
