arch/x86/include/asm/string_32.h

   1 #ifndef _ASM_X86_STRING_32_H
   2 #define _ASM_X86_STRING_32_H
   3
   4 #ifdef __KERNEL__
   5
   6 /* Let gcc decide whether to inline or use the out of line functions */
   7
   8 #define __HAVE_ARCH_STRCPY
   9 extern char *strcpy(char *dest, const char *src);
  10
  11 #define __HAVE_ARCH_STRNCPY
  12 extern char *strncpy(char *dest, const char *src, size_t count);
  13
  14 #define __HAVE_ARCH_STRCAT
  15 extern char *strcat(char *dest, const char *src);
  16
  17 #define __HAVE_ARCH_STRNCAT
  18 extern char *strncat(char *dest, const char *src, size_t count);
  19
  20 #define __HAVE_ARCH_STRCMP
  21 extern int strcmp(const char *cs, const char *ct);
  22
  23 #define __HAVE_ARCH_STRNCMP
  24 extern int strncmp(const char *cs, const char *ct, size_t count);
  25
  26 #define __HAVE_ARCH_STRCHR
  27 extern char *strchr(const char *s, int c);
  28
  29 #define __HAVE_ARCH_STRLEN
  30 extern size_t strlen(const char *s);
  31
  32 static __always_inline void *__memcpy(void *to, const void *from, size_t n)
  33 {
  34         int d0, d1, d2;
  35         asm volatile("rep ; movsl\n\t"
  36                      "movl %4,%%ecx\n\t"
  37                      "andl $3,%%ecx\n\t"
  38                      "jz 1f\n\t"
  39                      "rep ; movsb\n\t"
  40                      "1:"
  41                      : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  42                      : "0" (n / 4), "g" (n), "1" ((long)to), "2" ((long)from)
  43                      : "memory");
  44         return to;
  45 }
  46
  47 /*
  48  * This looks ugly, but the compiler can optimize it totally,
  49  * as the count is constant.
  50  */
  51 static __always_inline void *__constant_memcpy(void *to, const void *from,
  52                                                size_t n)
  53 {
  54         long esi, edi;
  55         if (!n)
  56                 return to;
  57
  58         switch (n) {
  59         case 1:
  60                 *(char *)to = *(char *)from;
  61                 return to;
  62         case 2:
  63                 *(short *)to = *(short *)from;
  64                 return to;
  65         case 4:
  66                 *(int *)to = *(int *)from;
  67                 return to;
  68         case 3:
  69                 *(short *)to = *(short *)from;
  70                 *((char *)to + 2) = *((char *)from + 2);
  71                 return to;
  72         case 5:
  73                 *(int *)to = *(int *)from;
  74                 *((char *)to + 4) = *((char *)from + 4);
  75                 return to;
  76         case 6:
  77                 *(int *)to = *(int *)from;
  78                 *((short *)to + 2) = *((short *)from + 2);
  79                 return to;
  80         case 8:
  81                 *(int *)to = *(int *)from;
  82                 *((int *)to + 1) = *((int *)from + 1);
  83                 return to;
  84         }
  85
  86         esi = (long)from;
  87         edi = (long)to;
  88         if (n >= 5 * 4) {
  89                 /* large block: use rep prefix */
  90                 int ecx;
  91                 asm volatile("rep ; movsl"
  92                              : "=&c" (ecx), "=&D" (edi), "=&S" (esi)
  93                              : "0" (n / 4), "1" (edi), "2" (esi)
  94                              : "memory"
  95                 );
  96         } else {
  97                 /* small block: don't clobber ecx + smaller code */
  98                 if (n >= 4 * 4)
  99                         asm volatile("movsl"
 100                                      : "=&D"(edi), "=&S"(esi)
 101                                      : "0"(edi), "1"(esi)
 102                                      : "memory");
 103                 if (n >= 3 * 4)
 104                         asm volatile("movsl"
 105                                      : "=&D"(edi), "=&S"(esi)
 106                                      : "0"(edi), "1"(esi)
 107                                      : "memory");
 108                 if (n >= 2 * 4)
 109                         asm volatile("movsl"
 110                                      : "=&D"(edi), "=&S"(esi)
 111                                      : "0"(edi), "1"(esi)
 112                                      : "memory");
 113                 if (n >= 1 * 4)
 114                         asm volatile("movsl"
 115                                      : "=&D"(edi), "=&S"(esi)
 116                                      : "0"(edi), "1"(esi)
 117                                      : "memory");
 118         }
 119         switch (n % 4) {
 120                 /* tail */
 121         case 0:
 122                 return to;
 123         case 1:
 124                 asm volatile("movsb"
 125                              : "=&D"(edi), "=&S"(esi)
 126                              : "0"(edi), "1"(esi)
 127                              : "memory");
 128                 return to;
 129         case 2:
 130                 asm volatile("movsw"
 131                              : "=&D"(edi), "=&S"(esi)
 132                              : "0"(edi), "1"(esi)
 133                              : "memory");
 134                 return to;
 135         default:
 136                 asm volatile("movsw\n\tmovsb"
 137                              : "=&D"(edi), "=&S"(esi)
 138                              : "0"(edi), "1"(esi)
 139                              : "memory");
 140                 return to;
 141         }
 142 }
 143
 144 #define __HAVE_ARCH_MEMCPY
 145 extern void *memcpy(void *, const void *, size_t);
 146
 147 #ifndef CONFIG_FORTIFY_SOURCE
 148 #ifdef CONFIG_X86_USE_3DNOW
 149
 150 #include <asm/mmx.h>
 151
 152 /*
 153  *      This CPU favours 3DNow strongly (eg AMD Athlon)
 154  */
 155
 156 static inline void *__constant_memcpy3d(void *to, const void *from, size_t len)
 157 {
 158         if (len < 512)
 159                 return __constant_memcpy(to, from, len);
 160         return _mmx_memcpy(to, from, len);
 161 }
 162
 163 static inline void *__memcpy3d(void *to, const void *from, size_t len)
 164 {
 165         if (len < 512)
 166                 return __memcpy(to, from, len);
 167         return _mmx_memcpy(to, from, len);
 168 }
 169
 170 #define memcpy(t, f, n)                         \
 171         (__builtin_constant_p((n))              \
 172          ? __constant_memcpy3d((t), (f), (n))   \
 173          : __memcpy3d((t), (f), (n)))
 174
 175 #else
 176
 177 /*
 178  *      No 3D Now!
 179  */
 180
 181 #ifndef CONFIG_KMEMCHECK
 182
 183 #if (__GNUC__ >= 4)
 184 #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
 185 #else
 186 #define memcpy(t, f, n)                         \
 187         (__builtin_constant_p((n))              \
 188          ? __constant_memcpy((t), (f), (n))     \
 189          : __memcpy((t), (f), (n)))
 190 #endif
 191 #else
 192 /*
 193  * kmemcheck becomes very happy if we use the REP instructions unconditionally,
 194  * because it means that we know both memory operands in advance.
 195  */
 196 #define memcpy(t, f, n) __memcpy((t), (f), (n))
 197 #endif
 198
 199 #endif
 200 #endif /* !CONFIG_FORTIFY_SOURCE */
 201
 202 #define __HAVE_ARCH_MEMMOVE
 203 void *memmove(void *dest, const void *src, size_t n);
 204
 205 extern int memcmp(const void *, const void *, size_t);
 206 #ifndef CONFIG_FORTIFY_SOURCE
 207 #define memcmp __builtin_memcmp
 208 #endif
 209
 210 #define __HAVE_ARCH_MEMCHR
 211 extern void *memchr(const void *cs, int c, size_t count);
 212
 213 static inline void *__memset_generic(void *s, char c, size_t count)
 214 {
 215         int d0, d1;
 216         asm volatile("rep\n\t"
 217                      "stosb"
 218                      : "=&c" (d0), "=&D" (d1)
 219                      : "a" (c), "1" (s), "0" (count)
 220                      : "memory");
 221         return s;
 222 }
 223
 224 /* we might want to write optimized versions of these later */
 225 #define __constant_count_memset(s, c, count) __memset_generic((s), (c), (count))
 226
 227 /*
 228  * memset(x, 0, y) is a reasonably common thing to do, so we want to fill
 229  * things 32 bits at a time even when we don't know the size of the
 230  * area at compile-time..
 231  */
 232 static __always_inline
 233 void *__constant_c_memset(void *s, unsigned long c, size_t count)
 234 {
 235         int d0, d1;
 236         asm volatile("rep ; stosl\n\t"
 237                      "testb $2,%b3\n\t"
 238                      "je 1f\n\t"
 239                      "stosw\n"
 240                      "1:\ttestb $1,%b3\n\t"
 241                      "je 2f\n\t"
 242                      "stosb\n"
 243                      "2:"
 244                      : "=&c" (d0), "=&D" (d1)
 245                      : "a" (c), "q" (count), "0" (count/4), "1" ((long)s)
 246                      : "memory");
 247         return s;
 248 }
 249
 250 /* Added by Gertjan van Wingerde to make minix and sysv module work */
 251 #define __HAVE_ARCH_STRNLEN
 252 extern size_t strnlen(const char *s, size_t count);
 253 /* end of additional stuff */
 254
 255 #define __HAVE_ARCH_STRSTR
 256 extern char *strstr(const char *cs, const char *ct);
 257
 258 /*
 259  * This looks horribly ugly, but the compiler can optimize it totally,
 260  * as we by now know that both pattern and count is constant..
 261  */
 262 static __always_inline
 263 void *__constant_c_and_count_memset(void *s, unsigned long pattern,
 264                                     size_t count)
 265 {
 266         switch (count) {
 267         case 0:
 268                 return s;
 269         case 1:
 270                 *(unsigned char *)s = pattern & 0xff;
 271                 return s;
 272         case 2:
 273                 *(unsigned short *)s = pattern & 0xffff;
 274                 return s;
 275         case 3:
 276                 *(unsigned short *)s = pattern & 0xffff;
 277                 *((unsigned char *)s + 2) = pattern & 0xff;
 278                 return s;
 279         case 4:
 280                 *(unsigned long *)s = pattern;
 281                 return s;
 282         }
 283
 284 #define COMMON(x)                                                       \
 285         asm volatile("rep ; stosl"                                      \
 286                      x                                                  \
 287                      : "=&c" (d0), "=&D" (d1)                           \
 288                      : "a" (eax), "0" (count/4), "1" ((long)s)  \
 289                      : "memory")
 290
 291         {
 292                 int d0, d1;
 293 #if __GNUC__ == 4 && __GNUC_MINOR__ == 0
 294                 /* Workaround for broken gcc 4.0 */
 295                 register unsigned long eax asm("%eax") = pattern;
 296 #else
 297                 unsigned long eax = pattern;
 298 #endif
 299
 300                 switch (count % 4) {
 301                 case 0:
 302                         COMMON("");
 303                         return s;
 304                 case 1:
 305                         COMMON("\n\tstosb");
 306                         return s;
 307                 case 2:
 308                         COMMON("\n\tstosw");
 309                         return s;
 310                 default:
 311                         COMMON("\n\tstosw\n\tstosb");
 312                         return s;
 313                 }
 314         }
 315
 316 #undef COMMON
 317 }
 318
 319 #define __constant_c_x_memset(s, c, count)                      \
 320         (__builtin_constant_p(count)                            \
 321          ? __constant_c_and_count_memset((s), (c), (count))     \
 322          : __constant_c_memset((s), (c), (count)))
 323
 324 #define __memset(s, c, count)                           \
 325         (__builtin_constant_p(count)                    \
 326          ? __constant_count_memset((s), (c), (count))   \
 327          : __memset_generic((s), (c), (count)))
 328
 329 #define __HAVE_ARCH_MEMSET
 330 extern void *memset(void *, int, size_t);
 331 #ifndef CONFIG_FORTIFY_SOURCE
 332 #if (__GNUC__ >= 4)
 333 #define memset(s, c, count) __builtin_memset(s, c, count)
 334 #else
 335 #define memset(s, c, count)                                             \
 336         (__builtin_constant_p(c)                                        \
 337          ? __constant_c_x_memset((s), (0x01010101UL * (unsigned char)(c)), \
 338                                  (count))                               \
 339          : __memset((s), (c), (count)))
 340 #endif
 341 #endif /* !CONFIG_FORTIFY_SOURCE */
 342
 343 /*
 344  * find the first occurrence of byte 'c', or 1 past the area if none
 345  */
 346 #define __HAVE_ARCH_MEMSCAN
 347 extern void *memscan(void *addr, int c, size_t size);
 348
 349 #endif /* __KERNEL__ */
 350
 351 #endif /* _ASM_X86_STRING_32_H */