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