arch/x86/include/asm/string_64.h

   1 #ifndef _ASM_X86_STRING_64_H
   2 #define _ASM_X86_STRING_64_H
   3
   4 #ifdef __KERNEL__
   5
   6 /* Written 2002 by Andi Kleen */
   7
   8 /* Only used for special circumstances. Stolen from i386/string.h */
   9 static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
  10 {
  11         unsigned long d0, d1, d2;
  12         asm volatile("rep ; movsl\n\t"
  13                      "testb $2,%b4\n\t"
  14                      "je 1f\n\t"
  15                      "movsw\n"
  16                      "1:\ttestb $1,%b4\n\t"
  17                      "je 2f\n\t"
  18                      "movsb\n"
  19                      "2:"
  20                      : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  21                      : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
  22                      : "memory");
  23         return to;
  24 }
  25
  26 /* Even with __builtin_ the compiler may decide to use the out of line
  27    function. */
  28
  29 #define __HAVE_ARCH_MEMCPY 1
  30 #ifndef CONFIG_KMEMCHECK
  31 #if (__GNUC__ == 4 && __GNUC_MINOR__ >= 3) || __GNUC__ > 4
  32 extern void *memcpy(void *to, const void *from, size_t len);
  33 #else
  34 extern void *__memcpy(void *to, const void *from, size_t len);
  35 #define memcpy(dst, src, len)                                   \
  36 ({                                                              \
  37         size_t __len = (len);                                   \
  38         void *__ret;                                            \
  39         if (__builtin_constant_p(len) && __len >= 64)           \
  40                 __ret = __memcpy((dst), (src), __len);          \
  41         else                                                    \
  42                 __ret = __builtin_memcpy((dst), (src), __len);  \
  43         __ret;                                                  \
  44 })
  45 #endif
  46 #else
  47 /*
  48  * kmemcheck becomes very happy if we use the REP instructions unconditionally,
  49  * because it means that we know both memory operands in advance.
  50  */
  51 #define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
  52 #endif
  53
  54 #define __HAVE_ARCH_MEMSET
  55 void *memset(void *s, int c, size_t n);
  56
  57 #define __HAVE_ARCH_MEMMOVE
  58 void *memmove(void *dest, const void *src, size_t count);
  59
  60 int memcmp(const void *cs, const void *ct, size_t count);
  61 size_t strlen(const char *s);
  62 char *strcpy(char *dest, const char *src);
  63 char *strcat(char *dest, const char *src);
  64 int strcmp(const char *cs, const char *ct);
  65
  66 #endif /* __KERNEL__ */
  67
  68 #endif /* _ASM_X86_STRING_64_H */