root/arch/x86/include/asm/string_64.h

INCLUDED FROM

DEFINITIONS

1. memset16
2. memset32
3. memset64
4. memcpy_mcsafe
5. memcpy_flushcache

   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 /* Even with __builtin_ the compiler may decide to use the out of line
  11    function. */
  12 
  13 #define __HAVE_ARCH_MEMCPY 1
  14 extern void *memcpy(void *to, const void *from, size_t len);
  15 extern void *__memcpy(void *to, const void *from, size_t len);
  16 
  17 #define __HAVE_ARCH_MEMSET
  18 void *memset(void *s, int c, size_t n);
  19 void *__memset(void *s, int c, size_t n);
  20 
  21 #define __HAVE_ARCH_MEMSET16
  22 static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
  23 {
  24         long d0, d1;
  25         asm volatile("rep\n\t"
  26                      "stosw"
  27                      : "=&c" (d0), "=&D" (d1)
  28                      : "a" (v), "1" (s), "0" (n)
  29                      : "memory");
  30         return s;
  31 }
  32 
  33 #define __HAVE_ARCH_MEMSET32
  34 static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
  35 {
  36         long d0, d1;
  37         asm volatile("rep\n\t"
  38                      "stosl"
  39                      : "=&c" (d0), "=&D" (d1)
  40                      : "a" (v), "1" (s), "0" (n)
  41                      : "memory");
  42         return s;
  43 }
  44 
  45 #define __HAVE_ARCH_MEMSET64
  46 static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
  47 {
  48         long d0, d1;
  49         asm volatile("rep\n\t"
  50                      "stosq"
  51                      : "=&c" (d0), "=&D" (d1)
  52                      : "a" (v), "1" (s), "0" (n)
  53                      : "memory");
  54         return s;
  55 }
  56 
  57 #define __HAVE_ARCH_MEMMOVE
  58 void *memmove(void *dest, const void *src, size_t count);
  59 void *__memmove(void *dest, const void *src, size_t count);
  60 
  61 int memcmp(const void *cs, const void *ct, size_t count);
  62 size_t strlen(const char *s);
  63 char *strcpy(char *dest, const char *src);
  64 char *strcat(char *dest, const char *src);
  65 int strcmp(const char *cs, const char *ct);
  66 
  67 #if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)
  68 
  69 /*
  70  * For files that not instrumented (e.g. mm/slub.c) we
  71  * should use not instrumented version of mem* functions.
  72  */
  73 
  74 #undef memcpy
  75 #define memcpy(dst, src, len) __memcpy(dst, src, len)
  76 #define memmove(dst, src, len) __memmove(dst, src, len)
  77 #define memset(s, c, n) __memset(s, c, n)
  78 
  79 #ifndef __NO_FORTIFY
  80 #define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
  81 #endif
  82 
  83 #endif
  84 
  85 #define __HAVE_ARCH_MEMCPY_MCSAFE 1
  86 __must_check unsigned long __memcpy_mcsafe(void *dst, const void *src,
  87                 size_t cnt);
  88 DECLARE_STATIC_KEY_FALSE(mcsafe_key);
  89 
  90 /**
  91  * memcpy_mcsafe - copy memory with indication if a machine check happened
  92  *
  93  * @dst:        destination address
  94  * @src:        source address
  95  * @cnt:        number of bytes to copy
  96  *
  97  * Low level memory copy function that catches machine checks
  98  * We only call into the "safe" function on systems that can
  99  * actually do machine check recovery. Everyone else can just
 100  * use memcpy().
 101  *
 102  * Return 0 for success, or number of bytes not copied if there was an
 103  * exception.
 104  */
 105 static __always_inline __must_check unsigned long
 106 memcpy_mcsafe(void *dst, const void *src, size_t cnt)
 107 {
 108 #ifdef CONFIG_X86_MCE
 109         if (static_branch_unlikely(&mcsafe_key))
 110                 return __memcpy_mcsafe(dst, src, cnt);
 111         else
 112 #endif
 113                 memcpy(dst, src, cnt);
 114         return 0;
 115 }
 116 
 117 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 118 #define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
 119 void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
 120 static __always_inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
 121 {
 122         if (__builtin_constant_p(cnt)) {
 123                 switch (cnt) {
 124                         case 4:
 125                                 asm ("movntil %1, %0" : "=m"(*(u32 *)dst) : "r"(*(u32 *)src));
 126                                 return;
 127                         case 8:
 128                                 asm ("movntiq %1, %0" : "=m"(*(u64 *)dst) : "r"(*(u64 *)src));
 129                                 return;
 130                         case 16:
 131                                 asm ("movntiq %1, %0" : "=m"(*(u64 *)dst) : "r"(*(u64 *)src));
 132                                 asm ("movntiq %1, %0" : "=m"(*(u64 *)(dst + 8)) : "r"(*(u64 *)(src + 8)));
 133                                 return;
 134                 }
 135         }
 136         __memcpy_flushcache(dst, src, cnt);
 137 }
 138 #endif
 139 
 140 #endif /* __KERNEL__ */
 141 
 142 #endif /* _ASM_X86_STRING_64_H */