1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_STRING_32_H
3 #define _ASM_X86_STRING_32_H
4
5 #ifdef __KERNEL__
6
7 /* Let gcc decide whether to inline or use the out of line functions */
8
9 #define __HAVE_ARCH_STRCPY
10 extern char *strcpy(char *dest, const char *src);
11
12 #define __HAVE_ARCH_STRNCPY
13 extern char *strncpy(char *dest, const char *src, size_t count);
14
15 #define __HAVE_ARCH_STRCAT
16 extern char *strcat(char *dest, const char *src);
17
18 #define __HAVE_ARCH_STRNCAT
19 extern char *strncat(char *dest, const char *src, size_t count);
20
21 #define __HAVE_ARCH_STRCMP
22 extern int strcmp(const char *cs, const char *ct);
23
24 #define __HAVE_ARCH_STRNCMP
25 extern int strncmp(const char *cs, const char *ct, size_t count);
26
27 #define __HAVE_ARCH_STRCHR
28 extern char *strchr(const char *s, int c);
29
30 #define __HAVE_ARCH_STRLEN
31 extern size_t strlen(const char *s);
32
__memcpy(void * to,const void * from,size_t n)33 static __always_inline void *__memcpy(void *to, const void *from, size_t n)
34 {
35 int d0, d1, d2;
36 asm volatile("rep ; movsl\n\t"
37 "movl %4,%%ecx\n\t"
38 "andl $3,%%ecx\n\t"
39 "jz 1f\n\t"
40 "rep ; movsb\n\t"
41 "1:"
42 : "=&c" (d0), "=&D" (d1), "=&S" (d2)
43 : "0" (n / 4), "g" (n), "1" ((long)to), "2" ((long)from)
44 : "memory");
45 return to;
46 }
47
48 /*
49 * This looks ugly, but the compiler can optimize it totally,
50 * as the count is constant.
51 */
__constant_memcpy(void * to,const void * from,size_t n)52 static __always_inline void *__constant_memcpy(void *to, const void *from,
53 size_t n)
54 {
55 long esi, edi;
56 if (!n)
57 return to;
58
59 switch (n) {
60 case 1:
61 *(char *)to = *(char *)from;
62 return to;
63 case 2:
64 *(short *)to = *(short *)from;
65 return to;
66 case 4:
67 *(int *)to = *(int *)from;
68 return to;
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 extern void *memcpy(void *, const void *, size_t);
147
148 #ifndef CONFIG_FORTIFY_SOURCE
149 #ifdef CONFIG_X86_USE_3DNOW
150
151 #include <asm/mmx.h>
152
153 /*
154 * This CPU favours 3DNow strongly (eg AMD Athlon)
155 */
156
__constant_memcpy3d(void * to,const void * from,size_t len)157 static inline void *__constant_memcpy3d(void *to, const void *from, size_t len)
158 {
159 if (len < 512)
160 return __constant_memcpy(to, from, len);
161 return _mmx_memcpy(to, from, len);
162 }
163
__memcpy3d(void * to,const void * from,size_t len)164 static inline void *__memcpy3d(void *to, const void *from, size_t len)
165 {
166 if (len < 512)
167 return __memcpy(to, from, len);
168 return _mmx_memcpy(to, from, len);
169 }
170
171 #define memcpy(t, f, n) \
172 (__builtin_constant_p((n)) \
173 ? __constant_memcpy3d((t), (f), (n)) \
174 : __memcpy3d((t), (f), (n)))
175
176 #else
177
178 /*
179 * No 3D Now!
180 */
181
182 #if (__GNUC__ >= 4)
183 #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
184 #else
185 #define memcpy(t, f, n) \
186 (__builtin_constant_p((n)) \
187 ? __constant_memcpy((t), (f), (n)) \
188 : __memcpy((t), (f), (n)))
189 #endif
190
191 #endif
192 #endif /* !CONFIG_FORTIFY_SOURCE */
193
194 #define __HAVE_ARCH_MEMMOVE
195 void *memmove(void *dest, const void *src, size_t n);
196
197 extern int memcmp(const void *, const void *, size_t);
198 #ifndef CONFIG_FORTIFY_SOURCE
199 #define memcmp __builtin_memcmp
200 #endif
201
202 #define __HAVE_ARCH_MEMCHR
203 extern void *memchr(const void *cs, int c, size_t count);
204
__memset_generic(void * s,char c,size_t count)205 static inline void *__memset_generic(void *s, char c, size_t count)
206 {
207 int d0, d1;
208 asm volatile("rep\n\t"
209 "stosb"
210 : "=&c" (d0), "=&D" (d1)
211 : "a" (c), "1" (s), "0" (count)
212 : "memory");
213 return s;
214 }
215
216 /* we might want to write optimized versions of these later */
217 #define __constant_count_memset(s, c, count) __memset_generic((s), (c), (count))
218
219 /*
220 * memset(x, 0, y) is a reasonably common thing to do, so we want to fill
221 * things 32 bits at a time even when we don't know the size of the
222 * area at compile-time..
223 */
224 static __always_inline
__constant_c_memset(void * s,unsigned long c,size_t count)225 void *__constant_c_memset(void *s, unsigned long c, size_t count)
226 {
227 int d0, d1;
228 asm volatile("rep ; stosl\n\t"
229 "testb $2,%b3\n\t"
230 "je 1f\n\t"
231 "stosw\n"
232 "1:\ttestb $1,%b3\n\t"
233 "je 2f\n\t"
234 "stosb\n"
235 "2:"
236 : "=&c" (d0), "=&D" (d1)
237 : "a" (c), "q" (count), "0" (count/4), "1" ((long)s)
238 : "memory");
239 return s;
240 }
241
242 /* Added by Gertjan van Wingerde to make minix and sysv module work */
243 #define __HAVE_ARCH_STRNLEN
244 extern size_t strnlen(const char *s, size_t count);
245 /* end of additional stuff */
246
247 #define __HAVE_ARCH_STRSTR
248 extern char *strstr(const char *cs, const char *ct);
249
250 /*
251 * This looks horribly ugly, but the compiler can optimize it totally,
252 * as we by now know that both pattern and count is constant..
253 */
254 static __always_inline
__constant_c_and_count_memset(void * s,unsigned long pattern,size_t count)255 void *__constant_c_and_count_memset(void *s, unsigned long pattern,
256 size_t count)
257 {
258 switch (count) {
259 case 0:
260 return s;
261 case 1:
262 *(unsigned char *)s = pattern & 0xff;
263 return s;
264 case 2:
265 *(unsigned short *)s = pattern & 0xffff;
266 return s;
267 case 3:
268 *(unsigned short *)s = pattern & 0xffff;
269 *((unsigned char *)s + 2) = pattern & 0xff;
270 return s;
271 case 4:
272 *(unsigned long *)s = pattern;
273 return s;
274 }
275
276 #define COMMON(x) \
277 asm volatile("rep ; stosl" \
278 x \
279 : "=&c" (d0), "=&D" (d1) \
280 : "a" (eax), "0" (count/4), "1" ((long)s) \
281 : "memory")
282
283 {
284 int d0, d1;
285 #if __GNUC__ == 4 && __GNUC_MINOR__ == 0
286 /* Workaround for broken gcc 4.0 */
287 register unsigned long eax asm("%eax") = pattern;
288 #else
289 unsigned long eax = pattern;
290 #endif
291
292 switch (count % 4) {
293 case 0:
294 COMMON("");
295 return s;
296 case 1:
297 COMMON("\n\tstosb");
298 return s;
299 case 2:
300 COMMON("\n\tstosw");
301 return s;
302 default:
303 COMMON("\n\tstosw\n\tstosb");
304 return s;
305 }
306 }
307
308 #undef COMMON
309 }
310
311 #define __constant_c_x_memset(s, c, count) \
312 (__builtin_constant_p(count) \
313 ? __constant_c_and_count_memset((s), (c), (count)) \
314 : __constant_c_memset((s), (c), (count)))
315
316 #define __memset(s, c, count) \
317 (__builtin_constant_p(count) \
318 ? __constant_count_memset((s), (c), (count)) \
319 : __memset_generic((s), (c), (count)))
320
321 #define __HAVE_ARCH_MEMSET
322 extern void *memset(void *, int, size_t);
323 #ifndef CONFIG_FORTIFY_SOURCE
324 #if (__GNUC__ >= 4)
325 #define memset(s, c, count) __builtin_memset(s, c, count)
326 #else
327 #define memset(s, c, count) \
328 (__builtin_constant_p(c) \
329 ? __constant_c_x_memset((s), (0x01010101UL * (unsigned char)(c)), \
330 (count)) \
331 : __memset((s), (c), (count)))
332 #endif
333 #endif /* !CONFIG_FORTIFY_SOURCE */
334
335 #define __HAVE_ARCH_MEMSET16
memset16(uint16_t * s,uint16_t v,size_t n)336 static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
337 {
338 int d0, d1;
339 asm volatile("rep\n\t"
340 "stosw"
341 : "=&c" (d0), "=&D" (d1)
342 : "a" (v), "1" (s), "0" (n)
343 : "memory");
344 return s;
345 }
346
347 #define __HAVE_ARCH_MEMSET32
memset32(uint32_t * s,uint32_t v,size_t n)348 static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
349 {
350 int d0, d1;
351 asm volatile("rep\n\t"
352 "stosl"
353 : "=&c" (d0), "=&D" (d1)
354 : "a" (v), "1" (s), "0" (n)
355 : "memory");
356 return s;
357 }
358
359 /*
360 * find the first occurrence of byte 'c', or 1 past the area if none
361 */
362 #define __HAVE_ARCH_MEMSCAN
363 extern void *memscan(void *addr, int c, size_t size);
364
365 #endif /* __KERNEL__ */
366
367 #endif /* _ASM_X86_STRING_32_H */
368
