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v4.6
 
  1/*
  2 *    Optimized string functions
  3 *
  4 *  S390 version
  5 *    Copyright IBM Corp. 2004
  6 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  7 */
  8
  9#define IN_ARCH_STRING_C 1
 10
 11#include <linux/types.h>
 12#include <linux/module.h>
 
 13
 14/*
 15 * Helper functions to find the end of a string
 16 */
 17static inline char *__strend(const char *s)
 18{
 19	register unsigned long r0 asm("0") = 0;
 20
 21	asm volatile ("0: srst  %0,%1\n"
 22		      "   jo    0b"
 23		      : "+d" (r0), "+a" (s) :  : "cc" );
 24	return (char *) r0;
 25}
 26
 27static inline char *__strnend(const char *s, size_t n)
 28{
 29	register unsigned long r0 asm("0") = 0;
 30	const char *p = s + n;
 31
 32	asm volatile ("0: srst  %0,%1\n"
 33		      "   jo    0b"
 34		      : "+d" (p), "+a" (s) : "d" (r0) : "cc" );
 35	return (char *) p;
 36}
 37
 38/**
 39 * strlen - Find the length of a string
 40 * @s: The string to be sized
 41 *
 42 * returns the length of @s
 43 */
 44size_t strlen(const char *s)
 45{
 46	return __strend(s) - s;
 47}
 48EXPORT_SYMBOL(strlen);
 49
 50/**
 51 * strnlen - Find the length of a length-limited string
 52 * @s: The string to be sized
 53 * @n: The maximum number of bytes to search
 54 *
 55 * returns the minimum of the length of @s and @n
 56 */
 57size_t strnlen(const char * s, size_t n)
 58{
 59	return __strnend(s, n) - s;
 60}
 61EXPORT_SYMBOL(strnlen);
 62
 63/**
 64 * strcpy - Copy a %NUL terminated string
 65 * @dest: Where to copy the string to
 66 * @src: Where to copy the string from
 67 *
 68 * returns a pointer to @dest
 69 */
 70char *strcpy(char *dest, const char *src)
 71{
 72	register int r0 asm("0") = 0;
 73	char *ret = dest;
 74
 75	asm volatile ("0: mvst  %0,%1\n"
 76		      "   jo    0b"
 77		      : "+&a" (dest), "+&a" (src) : "d" (r0)
 78		      : "cc", "memory" );
 79	return ret;
 80}
 81EXPORT_SYMBOL(strcpy);
 82
 83/**
 84 * strlcpy - Copy a %NUL terminated string into a sized buffer
 85 * @dest: Where to copy the string to
 86 * @src: Where to copy the string from
 87 * @size: size of destination buffer
 88 *
 89 * Compatible with *BSD: the result is always a valid
 90 * NUL-terminated string that fits in the buffer (unless,
 91 * of course, the buffer size is zero). It does not pad
 92 * out the result like strncpy() does.
 93 */
 94size_t strlcpy(char *dest, const char *src, size_t size)
 95{
 96	size_t ret = __strend(src) - src;
 97
 98	if (size) {
 99		size_t len = (ret >= size) ? size-1 : ret;
100		dest[len] = '\0';
101		memcpy(dest, src, len);
102	}
103	return ret;
104}
105EXPORT_SYMBOL(strlcpy);
106
107/**
108 * strncpy - Copy a length-limited, %NUL-terminated string
109 * @dest: Where to copy the string to
110 * @src: Where to copy the string from
111 * @n: The maximum number of bytes to copy
112 *
113 * The result is not %NUL-terminated if the source exceeds
114 * @n bytes.
115 */
116char *strncpy(char *dest, const char *src, size_t n)
117{
118	size_t len = __strnend(src, n) - src;
119	memset(dest + len, 0, n - len);
120	memcpy(dest, src, len);
121	return dest;
122}
123EXPORT_SYMBOL(strncpy);
124
125/**
126 * strcat - Append one %NUL-terminated string to another
127 * @dest: The string to be appended to
128 * @src: The string to append to it
129 *
130 * returns a pointer to @dest
131 */
132char *strcat(char *dest, const char *src)
133{
134	register int r0 asm("0") = 0;
135	unsigned long dummy;
136	char *ret = dest;
137
138	asm volatile ("0: srst  %0,%1\n"
139		      "   jo    0b\n"
140		      "1: mvst  %0,%2\n"
141		      "   jo    1b"
142		      : "=&a" (dummy), "+a" (dest), "+a" (src)
143		      : "d" (r0), "0" (0UL) : "cc", "memory" );
144	return ret;
145}
146EXPORT_SYMBOL(strcat);
147
148/**
149 * strlcat - Append a length-limited, %NUL-terminated string to another
150 * @dest: The string to be appended to
151 * @src: The string to append to it
152 * @n: The size of the destination buffer.
153 */
154size_t strlcat(char *dest, const char *src, size_t n)
155{
156	size_t dsize = __strend(dest) - dest;
157	size_t len = __strend(src) - src;
158	size_t res = dsize + len;
159
160	if (dsize < n) {
161		dest += dsize;
162		n -= dsize;
163		if (len >= n)
164			len = n - 1;
165		dest[len] = '\0';
166		memcpy(dest, src, len);
167	}
168	return res;
169}
170EXPORT_SYMBOL(strlcat);
171
172/**
173 * strncat - Append a length-limited, %NUL-terminated string to another
174 * @dest: The string to be appended to
175 * @src: The string to append to it
176 * @n: The maximum numbers of bytes to copy
177 *
178 * returns a pointer to @dest
179 *
180 * Note that in contrast to strncpy, strncat ensures the result is
181 * terminated.
182 */
183char *strncat(char *dest, const char *src, size_t n)
184{
185	size_t len = __strnend(src, n) - src;
186	char *p = __strend(dest);
187
188	p[len] = '\0';
189	memcpy(p, src, len);
190	return dest;
191}
192EXPORT_SYMBOL(strncat);
193
194/**
195 * strcmp - Compare two strings
196 * @cs: One string
197 * @ct: Another string
198 *
199 * returns   0 if @cs and @ct are equal,
200 *         < 0 if @cs is less than @ct
201 *         > 0 if @cs is greater than @ct
202 */
203int strcmp(const char *cs, const char *ct)
204{
205	register int r0 asm("0") = 0;
206	int ret = 0;
207
208	asm volatile ("0: clst %2,%3\n"
209		      "   jo   0b\n"
210		      "   je   1f\n"
211		      "   ic   %0,0(%2)\n"
212		      "   ic   %1,0(%3)\n"
213		      "   sr   %0,%1\n"
214		      "1:"
215		      : "+d" (ret), "+d" (r0), "+a" (cs), "+a" (ct)
216		      : : "cc" );
217	return ret;
218}
219EXPORT_SYMBOL(strcmp);
220
221/**
222 * strrchr - Find the last occurrence of a character in a string
223 * @s: The string to be searched
224 * @c: The character to search for
225 */
226char * strrchr(const char * s, int c)
227{
228       size_t len = __strend(s) - s;
229
230       if (len)
231	       do {
232		       if (s[len] == (char) c)
233			       return (char *) s + len;
234	       } while (--len > 0);
235       return NULL;
236}
237EXPORT_SYMBOL(strrchr);
238
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
239/**
240 * strstr - Find the first substring in a %NUL terminated string
241 * @s1: The string to be searched
242 * @s2: The string to search for
243 */
244char * strstr(const char * s1,const char * s2)
245{
246	int l1, l2;
247
248	l2 = __strend(s2) - s2;
249	if (!l2)
250		return (char *) s1;
251	l1 = __strend(s1) - s1;
252	while (l1-- >= l2) {
253		register unsigned long r2 asm("2") = (unsigned long) s1;
254		register unsigned long r3 asm("3") = (unsigned long) l2;
255		register unsigned long r4 asm("4") = (unsigned long) s2;
256		register unsigned long r5 asm("5") = (unsigned long) l2;
257		int cc;
258
259		asm volatile ("0: clcle %1,%3,0\n"
260			      "   jo    0b\n"
261			      "   ipm   %0\n"
262			      "   srl   %0,28"
263			      : "=&d" (cc), "+a" (r2), "+a" (r3),
264			        "+a" (r4), "+a" (r5) : : "cc" );
265		if (!cc)
266			return (char *) s1;
267		s1++;
268	}
269	return NULL;
270}
271EXPORT_SYMBOL(strstr);
272
273/**
274 * memchr - Find a character in an area of memory.
275 * @s: The memory area
276 * @c: The byte to search for
277 * @n: The size of the area.
278 *
279 * returns the address of the first occurrence of @c, or %NULL
280 * if @c is not found
281 */
282void *memchr(const void *s, int c, size_t n)
283{
284	register int r0 asm("0") = (char) c;
285	const void *ret = s + n;
286
287	asm volatile ("0: srst  %0,%1\n"
288		      "   jo    0b\n"
289		      "   jl	1f\n"
290		      "   la    %0,0\n"
291		      "1:"
292		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
293	return (void *) ret;
294}
295EXPORT_SYMBOL(memchr);
296
297/**
298 * memcmp - Compare two areas of memory
299 * @cs: One area of memory
300 * @ct: Another area of memory
301 * @count: The size of the area.
302 */
303int memcmp(const void *cs, const void *ct, size_t n)
304{
305	register unsigned long r2 asm("2") = (unsigned long) cs;
306	register unsigned long r3 asm("3") = (unsigned long) n;
307	register unsigned long r4 asm("4") = (unsigned long) ct;
308	register unsigned long r5 asm("5") = (unsigned long) n;
309	int ret;
310
311	asm volatile ("0: clcle %1,%3,0\n"
312		      "   jo    0b\n"
313		      "   ipm   %0\n"
314		      "   srl   %0,28"
315		      : "=&d" (ret), "+a" (r2), "+a" (r3), "+a" (r4), "+a" (r5)
316		      : : "cc" );
317	if (ret)
318		ret = *(char *) r2 - *(char *) r4;
319	return ret;
320}
321EXPORT_SYMBOL(memcmp);
322
323/**
324 * memscan - Find a character in an area of memory.
325 * @s: The memory area
326 * @c: The byte to search for
327 * @n: The size of the area.
328 *
329 * returns the address of the first occurrence of @c, or 1 byte past
330 * the area if @c is not found
331 */
332void *memscan(void *s, int c, size_t n)
333{
334	register int r0 asm("0") = (char) c;
335	const void *ret = s + n;
336
337	asm volatile ("0: srst  %0,%1\n"
338		      "   jo    0b\n"
339		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
340	return (void *) ret;
341}
342EXPORT_SYMBOL(memscan);
v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *    Optimized string functions
  4 *
  5 *  S390 version
  6 *    Copyright IBM Corp. 2004
  7 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  8 */
  9
 10#define IN_ARCH_STRING_C 1
 11
 12#include <linux/types.h>
 13#include <linux/string.h>
 14#include <linux/export.h>
 15
 16/*
 17 * Helper functions to find the end of a string
 18 */
 19static inline char *__strend(const char *s)
 20{
 21	register unsigned long r0 asm("0") = 0;
 22
 23	asm volatile ("0: srst  %0,%1\n"
 24		      "   jo    0b"
 25		      : "+d" (r0), "+a" (s) :  : "cc", "memory");
 26	return (char *) r0;
 27}
 28
 29static inline char *__strnend(const char *s, size_t n)
 30{
 31	register unsigned long r0 asm("0") = 0;
 32	const char *p = s + n;
 33
 34	asm volatile ("0: srst  %0,%1\n"
 35		      "   jo    0b"
 36		      : "+d" (p), "+a" (s) : "d" (r0) : "cc", "memory");
 37	return (char *) p;
 38}
 39
 40/**
 41 * strlen - Find the length of a string
 42 * @s: The string to be sized
 43 *
 44 * returns the length of @s
 45 */
 46size_t strlen(const char *s)
 47{
 48	return __strend(s) - s;
 49}
 50EXPORT_SYMBOL(strlen);
 51
 52/**
 53 * strnlen - Find the length of a length-limited string
 54 * @s: The string to be sized
 55 * @n: The maximum number of bytes to search
 56 *
 57 * returns the minimum of the length of @s and @n
 58 */
 59size_t strnlen(const char *s, size_t n)
 60{
 61	return __strnend(s, n) - s;
 62}
 63EXPORT_SYMBOL(strnlen);
 64
 65/**
 66 * strcpy - Copy a %NUL terminated string
 67 * @dest: Where to copy the string to
 68 * @src: Where to copy the string from
 69 *
 70 * returns a pointer to @dest
 71 */
 72char *strcpy(char *dest, const char *src)
 73{
 74	register int r0 asm("0") = 0;
 75	char *ret = dest;
 76
 77	asm volatile ("0: mvst  %0,%1\n"
 78		      "   jo    0b"
 79		      : "+&a" (dest), "+&a" (src) : "d" (r0)
 80		      : "cc", "memory" );
 81	return ret;
 82}
 83EXPORT_SYMBOL(strcpy);
 84
 85/**
 86 * strlcpy - Copy a %NUL terminated string into a sized buffer
 87 * @dest: Where to copy the string to
 88 * @src: Where to copy the string from
 89 * @size: size of destination buffer
 90 *
 91 * Compatible with *BSD: the result is always a valid
 92 * NUL-terminated string that fits in the buffer (unless,
 93 * of course, the buffer size is zero). It does not pad
 94 * out the result like strncpy() does.
 95 */
 96size_t strlcpy(char *dest, const char *src, size_t size)
 97{
 98	size_t ret = __strend(src) - src;
 99
100	if (size) {
101		size_t len = (ret >= size) ? size-1 : ret;
102		dest[len] = '\0';
103		memcpy(dest, src, len);
104	}
105	return ret;
106}
107EXPORT_SYMBOL(strlcpy);
108
109/**
110 * strncpy - Copy a length-limited, %NUL-terminated string
111 * @dest: Where to copy the string to
112 * @src: Where to copy the string from
113 * @n: The maximum number of bytes to copy
114 *
115 * The result is not %NUL-terminated if the source exceeds
116 * @n bytes.
117 */
118char *strncpy(char *dest, const char *src, size_t n)
119{
120	size_t len = __strnend(src, n) - src;
121	memset(dest + len, 0, n - len);
122	memcpy(dest, src, len);
123	return dest;
124}
125EXPORT_SYMBOL(strncpy);
126
127/**
128 * strcat - Append one %NUL-terminated string to another
129 * @dest: The string to be appended to
130 * @src: The string to append to it
131 *
132 * returns a pointer to @dest
133 */
134char *strcat(char *dest, const char *src)
135{
136	register int r0 asm("0") = 0;
137	unsigned long dummy;
138	char *ret = dest;
139
140	asm volatile ("0: srst  %0,%1\n"
141		      "   jo    0b\n"
142		      "1: mvst  %0,%2\n"
143		      "   jo    1b"
144		      : "=&a" (dummy), "+a" (dest), "+a" (src)
145		      : "d" (r0), "0" (0UL) : "cc", "memory" );
146	return ret;
147}
148EXPORT_SYMBOL(strcat);
149
150/**
151 * strlcat - Append a length-limited, %NUL-terminated string to another
152 * @dest: The string to be appended to
153 * @src: The string to append to it
154 * @n: The size of the destination buffer.
155 */
156size_t strlcat(char *dest, const char *src, size_t n)
157{
158	size_t dsize = __strend(dest) - dest;
159	size_t len = __strend(src) - src;
160	size_t res = dsize + len;
161
162	if (dsize < n) {
163		dest += dsize;
164		n -= dsize;
165		if (len >= n)
166			len = n - 1;
167		dest[len] = '\0';
168		memcpy(dest, src, len);
169	}
170	return res;
171}
172EXPORT_SYMBOL(strlcat);
173
174/**
175 * strncat - Append a length-limited, %NUL-terminated string to another
176 * @dest: The string to be appended to
177 * @src: The string to append to it
178 * @n: The maximum numbers of bytes to copy
179 *
180 * returns a pointer to @dest
181 *
182 * Note that in contrast to strncpy, strncat ensures the result is
183 * terminated.
184 */
185char *strncat(char *dest, const char *src, size_t n)
186{
187	size_t len = __strnend(src, n) - src;
188	char *p = __strend(dest);
189
190	p[len] = '\0';
191	memcpy(p, src, len);
192	return dest;
193}
194EXPORT_SYMBOL(strncat);
195
196/**
197 * strcmp - Compare two strings
198 * @s1: One string
199 * @s2: Another string
200 *
201 * returns   0 if @s1 and @s2 are equal,
202 *	   < 0 if @s1 is less than @s2
203 *	   > 0 if @s1 is greater than @s2
204 */
205int strcmp(const char *s1, const char *s2)
206{
207	register int r0 asm("0") = 0;
208	int ret = 0;
209
210	asm volatile ("0: clst %2,%3\n"
211		      "   jo   0b\n"
212		      "   je   1f\n"
213		      "   ic   %0,0(%2)\n"
214		      "   ic   %1,0(%3)\n"
215		      "   sr   %0,%1\n"
216		      "1:"
217		      : "+d" (ret), "+d" (r0), "+a" (s1), "+a" (s2)
218		      : : "cc", "memory");
219	return ret;
220}
221EXPORT_SYMBOL(strcmp);
222
223/**
224 * strrchr - Find the last occurrence of a character in a string
225 * @s: The string to be searched
226 * @c: The character to search for
227 */
228char *strrchr(const char *s, int c)
229{
230       size_t len = __strend(s) - s;
231
232       if (len)
233	       do {
234		       if (s[len] == (char) c)
235			       return (char *) s + len;
236	       } while (--len > 0);
237       return NULL;
238}
239EXPORT_SYMBOL(strrchr);
240
241static inline int clcle(const char *s1, unsigned long l1,
242			const char *s2, unsigned long l2)
243{
244	register unsigned long r2 asm("2") = (unsigned long) s1;
245	register unsigned long r3 asm("3") = (unsigned long) l1;
246	register unsigned long r4 asm("4") = (unsigned long) s2;
247	register unsigned long r5 asm("5") = (unsigned long) l2;
248	int cc;
249
250	asm volatile ("0: clcle %1,%3,0\n"
251		      "   jo    0b\n"
252		      "   ipm   %0\n"
253		      "   srl   %0,28"
254		      : "=&d" (cc), "+a" (r2), "+a" (r3),
255			"+a" (r4), "+a" (r5) : : "cc", "memory");
256	return cc;
257}
258
259/**
260 * strstr - Find the first substring in a %NUL terminated string
261 * @s1: The string to be searched
262 * @s2: The string to search for
263 */
264char *strstr(const char *s1, const char *s2)
265{
266	int l1, l2;
267
268	l2 = __strend(s2) - s2;
269	if (!l2)
270		return (char *) s1;
271	l1 = __strend(s1) - s1;
272	while (l1-- >= l2) {
 
 
 
 
273		int cc;
274
275		cc = clcle(s1, l2, s2, l2);
 
 
 
 
 
276		if (!cc)
277			return (char *) s1;
278		s1++;
279	}
280	return NULL;
281}
282EXPORT_SYMBOL(strstr);
283
284/**
285 * memchr - Find a character in an area of memory.
286 * @s: The memory area
287 * @c: The byte to search for
288 * @n: The size of the area.
289 *
290 * returns the address of the first occurrence of @c, or %NULL
291 * if @c is not found
292 */
293void *memchr(const void *s, int c, size_t n)
294{
295	register int r0 asm("0") = (char) c;
296	const void *ret = s + n;
297
298	asm volatile ("0: srst  %0,%1\n"
299		      "   jo    0b\n"
300		      "   jl	1f\n"
301		      "   la    %0,0\n"
302		      "1:"
303		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
304	return (void *) ret;
305}
306EXPORT_SYMBOL(memchr);
307
308/**
309 * memcmp - Compare two areas of memory
310 * @s1: One area of memory
311 * @s2: Another area of memory
312 * @count: The size of the area.
313 */
314int memcmp(const void *s1, const void *s2, size_t n)
315{
 
 
 
 
316	int ret;
317
318	ret = clcle(s1, n, s2, n);
 
 
 
 
 
319	if (ret)
320		ret = ret == 1 ? -1 : 1;
321	return ret;
322}
323EXPORT_SYMBOL(memcmp);
324
325/**
326 * memscan - Find a character in an area of memory.
327 * @s: The memory area
328 * @c: The byte to search for
329 * @n: The size of the area.
330 *
331 * returns the address of the first occurrence of @c, or 1 byte past
332 * the area if @c is not found
333 */
334void *memscan(void *s, int c, size_t n)
335{
336	register int r0 asm("0") = (char) c;
337	const void *ret = s + n;
338
339	asm volatile ("0: srst  %0,%1\n"
340		      "   jo    0b\n"
341		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc", "memory");
342	return (void *) ret;
343}
344EXPORT_SYMBOL(memscan);