arch/x86/include/asm/string_64.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_STRING_64_H
   3 #define _ASM_X86_STRING_64_H
   4
   5 #ifdef __KERNEL__
   6 #include <linux/jump_label.h>
   7
   8 /* Written 2002 by Andi Kleen */
   9
  10 /* Only used for special circumstances. Stolen from i386/string.h */
  11 static __always_inline void *__inline_memcpy(void *to, const void *from, size_t n)
  12 {
  13         unsigned long d0, d1, d2;
  14         asm volatile("rep ; movsl\n\t"
  15                      "testb $2,%b4\n\t"
  16                      "je 1f\n\t"
  17                      "movsw\n"
  18                      "1:\ttestb $1,%b4\n\t"
  19                      "je 2f\n\t"
  20                      "movsb\n"
  21                      "2:"
  22                      : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  23                      : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
  24                      : "memory");
  25         return to;
  26 }
  27
  28 /* Even with __builtin_ the compiler may decide to use the out of line
  29    function. */
  30
  31 #define __HAVE_ARCH_MEMCPY 1
  32 extern void *memcpy(void *to, const void *from, size_t len);
  33 extern void *__memcpy(void *to, const void *from, size_t len);
  34
  35 #define __HAVE_ARCH_MEMSET
  36 void *memset(void *s, int c, size_t n);
  37 void *__memset(void *s, int c, size_t n);
  38
  39 #define __HAVE_ARCH_MEMSET16
  40 static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
  41 {
  42         long d0, d1;
  43         asm volatile("rep\n\t"
  44                      "stosw"
  45                      : "=&c" (d0), "=&D" (d1)
  46                      : "a" (v), "1" (s), "0" (n)
  47                      : "memory");
  48         return s;
  49 }
  50
  51 #define __HAVE_ARCH_MEMSET32
  52 static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
  53 {
  54         long d0, d1;
  55         asm volatile("rep\n\t"
  56                      "stosl"
  57                      : "=&c" (d0), "=&D" (d1)
  58                      : "a" (v), "1" (s), "0" (n)
  59                      : "memory");
  60         return s;
  61 }
  62
  63 #define __HAVE_ARCH_MEMSET64
  64 static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
  65 {
  66         long d0, d1;
  67         asm volatile("rep\n\t"
  68                      "stosq"
  69                      : "=&c" (d0), "=&D" (d1)
  70                      : "a" (v), "1" (s), "0" (n)
  71                      : "memory");
  72         return s;
  73 }
  74
  75 #define __HAVE_ARCH_MEMMOVE
  76 void *memmove(void *dest, const void *src, size_t count);
  77 void *__memmove(void *dest, const void *src, size_t count);
  78
  79 int memcmp(const void *cs, const void *ct, size_t count);
  80 size_t strlen(const char *s);
  81 char *strcpy(char *dest, const char *src);
  82 char *strcat(char *dest, const char *src);
  83 int strcmp(const char *cs, const char *ct);
  84
  85 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
  86
  87 /*
  88  * For files that not instrumented (e.g. mm/slub.c) we
  89  * should use not instrumented version of mem* functions.
  90  */
  91
  92 #undef memcpy
  93 #define memcpy(dst, src, len) __memcpy(dst, src, len)
  94 #define memmove(dst, src, len) __memmove(dst, src, len)
  95 #define memset(s, c, n) __memset(s, c, n)
  96
  97 #ifndef __NO_FORTIFY
  98 #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
  99 #endif
 100
 101 #endif
 102
 103 #define __HAVE_ARCH_MEMCPY_MCSAFE 1
 104 __must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
 105                 size_t cnt);
 106 DECLARE_STATIC_KEY_FALSE(mcsafe_key);
 107
 108 /**
 109  * memcpy_mcsafe - copy memory with indication if a machine check happened
 110  *
 111  * @dst:        destination address
 112  * @src:        source address
 113  * @cnt:        number of bytes to copy
 114  *
 115  * Low level memory copy function that catches machine checks
 116  * We only call into the "safe" function on systems that can
 117  * actually do machine check recovery. Everyone else can just
 118  * use memcpy().
 119  *
 120  * Return 0 for success, or number of bytes not copied if there was an
 121  * exception.
 122  */
 123 static __always_inline __must_check unsigned long
 124 memcpy_mcsafe(void *dst, const void *src, size_t cnt)
 125 {
 126 #ifdef CONFIG_X86_MCE
 127         if (static_branch_unlikely(&mcsafe_key))
 128                 return __memcpy_mcsafe(dst, src, cnt);
 129         else
 130 #endif
 131                 memcpy(dst, src, cnt);
 132         return 0;
 133 }
 134
 135 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 136 #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
 137 void memcpy_flushcache(void *dst, const void *src, size_t cnt);
 138 #endif
 139
 140 #endif /* __KERNEL__ */
 141
 142 #endif /* _ASM_X86_STRING_64_H */