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 #define memcpy(t, f, n) __builtin_memcpy(t, f, n)
183
184 #endif
185 #endif /* !CONFIG_FORTIFY_SOURCE */
186
187 #define __HAVE_ARCH_MEMMOVE
188 void *memmove(void *dest, const void *src, size_t n);
189
190 extern int memcmp(const void *, const void *, size_t);
191 #ifndef CONFIG_FORTIFY_SOURCE
192 #define memcmp __builtin_memcmp
193 #endif
194
195 #define __HAVE_ARCH_MEMCHR
196 extern void *memchr(const void *cs, int c, size_t count);
197
__memset_generic(void * s,char c,size_t count)198 static inline void *__memset_generic(void *s, char c, size_t count)
199 {
200 int d0, d1;
201 asm volatile("rep\n\t"
202 "stosb"
203 : "=&c" (d0), "=&D" (d1)
204 : "a" (c), "1" (s), "0" (count)
205 : "memory");
206 return s;
207 }
208
209 /* we might want to write optimized versions of these later */
210 #define __constant_count_memset(s, c, count) __memset_generic((s), (c), (count))
211
212 /*
213 * memset(x, 0, y) is a reasonably common thing to do, so we want to fill
214 * things 32 bits at a time even when we don't know the size of the
215 * area at compile-time..
216 */
217 static __always_inline
__constant_c_memset(void * s,unsigned long c,size_t count)218 void *__constant_c_memset(void *s, unsigned long c, size_t count)
219 {
220 int d0, d1;
221 asm volatile("rep ; stosl\n\t"
222 "testb $2,%b3\n\t"
223 "je 1f\n\t"
224 "stosw\n"
225 "1:\ttestb $1,%b3\n\t"
226 "je 2f\n\t"
227 "stosb\n"
228 "2:"
229 : "=&c" (d0), "=&D" (d1)
230 : "a" (c), "q" (count), "0" (count/4), "1" ((long)s)
231 : "memory");
232 return s;
233 }
234
235 /* Added by Gertjan van Wingerde to make minix and sysv module work */
236 #define __HAVE_ARCH_STRNLEN
237 extern size_t strnlen(const char *s, size_t count);
238 /* end of additional stuff */
239
240 #define __HAVE_ARCH_STRSTR
241 extern char *strstr(const char *cs, const char *ct);
242
243 /*
244 * This looks horribly ugly, but the compiler can optimize it totally,
245 * as we by now know that both pattern and count is constant..
246 */
247 static __always_inline
__constant_c_and_count_memset(void * s,unsigned long pattern,size_t count)248 void *__constant_c_and_count_memset(void *s, unsigned long pattern,
249 size_t count)
250 {
251 switch (count) {
252 case 0:
253 return s;
254 case 1:
255 *(unsigned char *)s = pattern & 0xff;
256 return s;
257 case 2:
258 *(unsigned short *)s = pattern & 0xffff;
259 return s;
260 case 3:
261 *(unsigned short *)s = pattern & 0xffff;
262 *((unsigned char *)s + 2) = pattern & 0xff;
263 return s;
264 case 4:
265 *(unsigned long *)s = pattern;
266 return s;
267 }
268
269 #define COMMON(x) \
270 asm volatile("rep ; stosl" \
271 x \
272 : "=&c" (d0), "=&D" (d1) \
273 : "a" (eax), "0" (count/4), "1" ((long)s) \
274 : "memory")
275
276 {
277 int d0, d1;
278 unsigned long eax = pattern;
279
280 switch (count % 4) {
281 case 0:
282 COMMON("");
283 return s;
284 case 1:
285 COMMON("\n\tstosb");
286 return s;
287 case 2:
288 COMMON("\n\tstosw");
289 return s;
290 default:
291 COMMON("\n\tstosw\n\tstosb");
292 return s;
293 }
294 }
295
296 #undef COMMON
297 }
298
299 #define __constant_c_x_memset(s, c, count) \
300 (__builtin_constant_p(count) \
301 ? __constant_c_and_count_memset((s), (c), (count)) \
302 : __constant_c_memset((s), (c), (count)))
303
304 #define __memset(s, c, count) \
305 (__builtin_constant_p(count) \
306 ? __constant_count_memset((s), (c), (count)) \
307 : __memset_generic((s), (c), (count)))
308
309 #define __HAVE_ARCH_MEMSET
310 extern void *memset(void *, int, size_t);
311 #ifndef CONFIG_FORTIFY_SOURCE
312 #define memset(s, c, count) __builtin_memset(s, c, count)
313 #endif /* !CONFIG_FORTIFY_SOURCE */
314
315 #define __HAVE_ARCH_MEMSET16
memset16(uint16_t * s,uint16_t v,size_t n)316 static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
317 {
318 int d0, d1;
319 asm volatile("rep\n\t"
320 "stosw"
321 : "=&c" (d0), "=&D" (d1)
322 : "a" (v), "1" (s), "0" (n)
323 : "memory");
324 return s;
325 }
326
327 #define __HAVE_ARCH_MEMSET32
memset32(uint32_t * s,uint32_t v,size_t n)328 static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
329 {
330 int d0, d1;
331 asm volatile("rep\n\t"
332 "stosl"
333 : "=&c" (d0), "=&D" (d1)
334 : "a" (v), "1" (s), "0" (n)
335 : "memory");
336 return s;
337 }
338
339 /*
340 * find the first occurrence of byte 'c', or 1 past the area if none
341 */
342 #define __HAVE_ARCH_MEMSCAN
343 extern void *memscan(void *addr, int c, size_t size);
344
345 #endif /* __KERNEL__ */
346
347 #endif /* _ASM_X86_STRING_32_H */
348