aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/string_32.h
blob: 487843ed245a54bd91dadaca58413b650b0976cb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
#ifndef ASM_X86__STRING_32_H
#define ASM_X86__STRING_32_H

#ifdef __KERNEL__

/* Let gcc decide whether to inline or use the out of line functions */

#define __HAVE_ARCH_STRCPY
extern char *strcpy(char *dest, const char *src);

#define __HAVE_ARCH_STRNCPY
extern char *strncpy(char *dest, const char *src, size_t count);

#define __HAVE_ARCH_STRCAT
extern char *strcat(char *dest, const char *src);

#define __HAVE_ARCH_STRNCAT
extern char *strncat(char *dest, const char *src, size_t count);

#define __HAVE_ARCH_STRCMP
extern int strcmp(const char *cs, const char *ct);

#define __HAVE_ARCH_STRNCMP
extern int strncmp(const char *cs, const char *ct, size_t count);

#define __HAVE_ARCH_STRCHR
extern char *strchr(const char *s, int c);

#define __HAVE_ARCH_STRLEN
extern size_t strlen(const char *s);

static __always_inline void *__memcpy(void *to, const void *from, size_t n)
{
	int d0, d1, d2;
	asm volatile("rep ; movsl\n\t"
		     "movl %4,%%ecx\n\t"
		     "andl $3,%%ecx\n\t"
		     "jz 1f\n\t"
		     "rep ; movsb\n\t"
		     "1:"
		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
		     : "0" (n / 4), "g" (n), "1" ((long)to), "2" ((long)from)
		     : "memory");
	return to;
}

/*
 * This looks ugly, but the compiler can optimize it totally,
 * as the count is constant.
 */
static __always_inline void *__constant_memcpy(void *to, const void *from,
					       size_t n)
{
	long esi, edi;
	if (!n)
		return to;

	switch (n) {
	case 1:
		*(char *)to = *(char *)from;
		return to;
	case 2:
		*(short *)to = *(short *)from;
		return to;
	case 4:
		*(int *)to = *(int *)from;
		return to;

	case 3:
		*(short *)to = *(short *)from;
		*((char *)to + 2) = *((char *)from + 2);
		return to;
	case 5:
		*(int *)to = *(int *)from;
		*((char *)to + 4) = *((char *)from + 4);
		return to;
	case 6:
		*(int *)to = *(int *)from;
		*((short *)to + 2) = *((short *)from + 2);
		return to;
	case 8:
		*(int *)to = *(int *)from;
		*((int *)to + 1) = *((int *)from + 1);
		return to;
	}

	esi = (long)from;
	edi = (long)to;
	if (n >= 5 * 4) {
		/* large block: use rep prefix */
		int ecx;
		asm volatile("rep ; movsl"
			     : "=&c" (ecx), "=&D" (edi), "=&S" (esi)
			     : "0" (n / 4), "1" (edi), "2" (esi)
			     : "memory"
		);
	} else {
		/* small block: don't clobber ecx + smaller code */
		if (n >= 4 * 4)
			asm volatile("movsl"
				     : "=&D"(edi), "=&S"(esi)
				     : "0"(edi), "1"(esi)
				     : "memory");
		if (n >= 3 * 4)
			asm volatile("movsl"
				     : "=&D"(edi), "=&S"(esi)
				     : "0"(edi), "1"(esi)
				     : "memory");
		if (n >= 2 * 4)
			asm volatile("movsl"
				     : "=&D"(edi), "=&S"(esi)
				     : "0"(edi), "1"(esi)
				     : "memory");
		if (n >= 1 * 4)
			asm volatile("movsl"
				     : "=&D"(edi), "=&S"(esi)
				     : "0"(edi), "1"(esi)
				     : "memory");
	}
	switch (n % 4) {
		/* tail */
	case 0:
		return to;
	case 1:
		asm volatile("movsb"
			     : "=&D"(edi), "=&S"(esi)
			     : "0"(edi), "1"(esi)
			     : "memory");
		return to;
	case 2:
		asm volatile("movsw"
			     : "=&D"(edi), "=&S"(esi)
			     : "0"(edi), "1"(esi)
			     : "memory");
		return to;
	default:
		asm volatile("movsw\n\tmovsb"
			     : "=&D"(edi), "=&S"(esi)
			     : "0"(edi), "1"(esi)
			     : "memory");
		return to;
	}
}

#define __HAVE_ARCH_MEMCPY

#ifdef CONFIG_X86_USE_3DNOW

#include <asm/mmx.h>

/*
 *	This CPU favours 3DNow strongly (eg AMD Athlon)
 */

static inline void *__constant_memcpy3d(void *to, const void *from, size_t len)
{
	if (len < 512)
		return __constant_memcpy(to, from, len);
	return _mmx_memcpy(to, from, len);
}

static inline void *__memcpy3d(void *to, const void *from, size_t len)
{
	if (len < 512)
		return __memcpy(to, from, len);
	return _mmx_memcpy(to, from, len);
}

#define memcpy(t, f, n)				\
	(__builtin_constant_p((n))		\
	 ? __constant_memcpy3d((t), (f), (n))	\
	 : __memcpy3d((t), (f), (n)))

#else

/*
 *	No 3D Now!
 */

#define memcpy(t, f, n)				\
	(__builtin_constant_p((n))		\
	 ? __constant_memcpy((t), (f), (n))	\
	 : __memcpy((t), (f), (n)))

#endif

#define __HAVE_ARCH_MEMMOVE
void *memmove(void *dest, const void *src, size_t n);

#define memcmp __builtin_memcmp

#define __HAVE_ARCH_MEMCHR
extern void *memchr(const void *cs, int c, size_t count);

static inline void *__memset_generic(void *s, char c, size_t count)
{
	int d0, d1;
	asm volatile("rep\n\t"
		     "stosb"
		     : "=&c" (d0), "=&D" (d1)
		     : "a" (c), "1" (s), "0" (count)
		     : "memory");
	return s;
}

/* we might want to write optimized versions of these later */
#define __constant_count_memset(s, c, count) __memset_generic((s), (c), (count))

/*
 * memset(x, 0, y) is a reasonably common thing to do, so we want to fill
 * things 32 bits at a time even when we don't know the size of the
 * area at compile-time..
 */
static __always_inline
void *__constant_c_memset(void *s, unsigned long c, size_t count)
{
	int d0, d1;
	asm volatile("rep ; stosl\n\t"
		     "testb $2,%b3\n\t"
		     "je 1f\n\t"
		     "stosw\n"
		     "1:\ttestb $1,%b3\n\t"
		     "je 2f\n\t"
		     "stosb\n"
		     "2:"
		     : "=&c" (d0), "=&D" (d1)
		     : "a" (c), "q" (count), "0" (count/4), "1" ((long)s)
		     : "memory");
	return s;
}

/* Added by Gertjan van Wingerde to make minix and sysv module work */
#define __HAVE_ARCH_STRNLEN
extern size_t strnlen(const char *s, size_t count);
/* end of additional stuff */

#define __HAVE_ARCH_STRSTR
extern char *strstr(const char *cs, const char *ct);

/*
 * This looks horribly ugly, but the compiler can optimize it totally,
 * as we by now know that both pattern and count is constant..
 */
static __always_inline
void *__constant_c_and_count_memset(void *s, unsigned long pattern,
				    size_t count)
{
	switch (count) {
	case 0:
		return s;
	case 1:
		*(unsigned char *)s = pattern & 0xff;
		return s;
	case 2:
		*(unsigned short *)s = pattern & 0xffff;
		return s;
	case 3:
		*(unsigned short *)s = pattern & 0xffff;
		*((unsigned char *)s + 2) = pattern & 0xff;
		return s;
	case 4:
		*(unsigned long *)s = pattern;
		return s;
	}

#define COMMON(x)							\
	asm volatile("rep ; stosl"					\
		     x							\
		     : "=&c" (d0), "=&D" (d1)				\
		     : "a" (eax), "0" (count/4), "1" ((long)s)	\
		     : "memory")

	{
		int d0, d1;
#if __GNUC__ == 4 && __GNUC_MINOR__ == 0
		/* Workaround for broken gcc 4.0 */
		register unsigned long eax asm("%eax") = pattern;
#else
		unsigned long eax = pattern;
#endif

		switch (count % 4) {
		case 0:
			COMMON("");
			return s;
		case 1:
			COMMON("\n\tstosb");
			return s;
		case 2:
			COMMON("\n\tstosw");
			return s;
		default:
			COMMON("\n\tstosw\n\tstosb");
			return s;
		}
	}

#undef COMMON
}

#define __constant_c_x_memset(s, c, count)			\
	(__builtin_constant_p(count)				\
	 ? __constant_c_and_count_memset((s), (c), (count))	\
	 : __constant_c_memset((s), (c), (count)))

#define __memset(s, c, count)				\
	(__builtin_constant_p(count)			\
	 ? __constant_count_memset((s), (c), (count))	\
	 : __memset_generic((s), (c), (count)))

#define __HAVE_ARCH_MEMSET
#define memset(s, c, count)						\
	(__builtin_constant_p(c)					\
	 ? __constant_c_x_memset((s), (0x01010101UL * (unsigned char)(c)), \
				 (count))				\
	 : __memset((s), (c), (count)))

/*
 * find the first occurrence of byte 'c', or 1 past the area if none
 */
#define __HAVE_ARCH_MEMSCAN
extern void *memscan(void *addr, int c, size_t size);

#endif /* __KERNEL__ */

#endif /* ASM_X86__STRING_32_H */