[linux-2.6-block.git] / arch / s390 / lib / string.c

/*
 *  arch/s390/lib/string.c
 *    Optimized string functions
 *
 *  S390 version
 *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
 */

#define IN_ARCH_STRING_C 1

#include <linux/types.h>
#include <linux/module.h>

/*
 * Helper functions to find the end of a string
 */
static inline char *__strend(const char *s)
{
	register unsigned long r0 asm("0") = 0;

	asm volatile ("0: srst  %0,%1\n"
		      "   jo    0b"
		      : "+d" (r0), "+a" (s) :  : "cc" );
	return (char *) r0;
}

static inline char *__strnend(const char *s, size_t n)
{
	register unsigned long r0 asm("0") = 0;
	const char *p = s + n;

	asm volatile ("0: srst  %0,%1\n"
		      "   jo    0b"
		      : "+d" (p), "+a" (s) : "d" (r0) : "cc" );
	return (char *) p;
}

/**
 * strlen - Find the length of a string
 * @s: The string to be sized
 *
 * returns the length of @s
 */
size_t strlen(const char *s)
{
#if __GNUC__ < 4
	return __strend(s) - s;
#else
	return __builtin_strlen(s);
#endif
}
EXPORT_SYMBOL(strlen);

/**
 * strnlen - Find the length of a length-limited string
 * @s: The string to be sized
 * @n: The maximum number of bytes to search
 *
 * returns the minimum of the length of @s and @n
 */
size_t strnlen(const char * s, size_t n)
{
	return __strnend(s, n) - s;
}
EXPORT_SYMBOL(strnlen);

/**
 * strcpy - Copy a %NUL terminated string
 * @dest: Where to copy the string to
 * @src: Where to copy the string from
 *
 * returns a pointer to @dest
 */
char *strcpy(char *dest, const char *src)
{
#if __GNUC__ < 4
	register int r0 asm("0") = 0;
	char *ret = dest;

	asm volatile ("0: mvst  %0,%1\n"
		      "   jo    0b"
		      : "+&a" (dest), "+&a" (src) : "d" (r0)
		      : "cc", "memory" );
	return ret;
#else
	return __builtin_strcpy(dest, src);
#endif
}
EXPORT_SYMBOL(strcpy);

/**
 * strlcpy - Copy a %NUL terminated string into a sized buffer
 * @dest: Where to copy the string to
 * @src: Where to copy the string from
 * @size: size of destination buffer
 *
 * Compatible with *BSD: the result is always a valid
 * NUL-terminated string that fits in the buffer (unless,
 * of course, the buffer size is zero). It does not pad
 * out the result like strncpy() does.
 */
size_t strlcpy(char *dest, const char *src, size_t size)
{
	size_t ret = __strend(src) - src;

	if (size) {
		size_t len = (ret >= size) ? size-1 : ret;
		dest[len] = '\0';
		__builtin_memcpy(dest, src, len);
	}
	return ret;
}
EXPORT_SYMBOL(strlcpy);

/**
 * strncpy - Copy a length-limited, %NUL-terminated string
 * @dest: Where to copy the string to
 * @src: Where to copy the string from
 * @n: The maximum number of bytes to copy
 *
 * The result is not %NUL-terminated if the source exceeds
 * @n bytes.
 */
char *strncpy(char *dest, const char *src, size_t n)
{
	size_t len = __strnend(src, n) - src;
	__builtin_memset(dest + len, 0, n - len);
	__builtin_memcpy(dest, src, len);
	return dest;
}
EXPORT_SYMBOL(strncpy);

/**
 * strcat - Append one %NUL-terminated string to another
 * @dest: The string to be appended to
 * @src: The string to append to it
 *
 * returns a pointer to @dest
 */
char *strcat(char *dest, const char *src)
{
	register int r0 asm("0") = 0;
	unsigned long dummy;
	char *ret = dest;

	asm volatile ("0: srst  %0,%1\n"
		      "   jo    0b\n"
		      "1: mvst  %0,%2\n"
		      "   jo    1b"
		      : "=&a" (dummy), "+a" (dest), "+a" (src)
		      : "d" (r0), "0" (0UL) : "cc", "memory" );
	return ret;
}
EXPORT_SYMBOL(strcat);

/**
 * strlcat - Append a length-limited, %NUL-terminated string to another
 * @dest: The string to be appended to
 * @src: The string to append to it
 * @n: The size of the destination buffer.
 */
size_t strlcat(char *dest, const char *src, size_t n)
{
	size_t dsize = __strend(dest) - dest;
	size_t len = __strend(src) - src;
	size_t res = dsize + len;

	if (dsize < n) {
		dest += dsize;
		n -= dsize;
		if (len >= n)
			len = n - 1;
		dest[len] = '\0';
		__builtin_memcpy(dest, src, len);
	}
	return res;
}
EXPORT_SYMBOL(strlcat);

/**
 * strncat - Append a length-limited, %NUL-terminated string to another
 * @dest: The string to be appended to
 * @src: The string to append to it
 * @n: The maximum numbers of bytes to copy
 *
 * returns a pointer to @dest
 *
 * Note that in contrast to strncpy, strncat ensures the result is
 * terminated.
 */
char *strncat(char *dest, const char *src, size_t n)
{
	size_t len = __strnend(src, n) - src;
	char *p = __strend(dest);

	p[len] = '\0';
	__builtin_memcpy(p, src, len);
	return dest;
}
EXPORT_SYMBOL(strncat);

/**
 * strcmp - Compare two strings
 * @cs: One string
 * @ct: Another string
 *
 * returns   0 if @cs and @ct are equal,
 *         < 0 if @cs is less than @ct
 *         > 0 if @cs is greater than @ct
 */
int strcmp(const char *cs, const char *ct)
{
	register int r0 asm("0") = 0;
	int ret = 0;

	asm volatile ("0: clst %2,%3\n"
		      "   jo   0b\n"
		      "   je   1f\n"
		      "   ic   %0,0(%2)\n"
		      "   ic   %1,0(%3)\n"
		      "   sr   %0,%1\n"
		      "1:"
		      : "+d" (ret), "+d" (r0), "+a" (cs), "+a" (ct)
		      : : "cc" );
	return ret;
}
EXPORT_SYMBOL(strcmp);

/**
 * strrchr - Find the last occurrence of a character in a string
 * @s: The string to be searched
 * @c: The character to search for
 */
char * strrchr(const char * s, int c)
{
       size_t len = __strend(s) - s;

       if (len)
	       do {
		       if (s[len] == (char) c)
			       return (char *) s + len;
	       } while (--len > 0);
       return NULL;
}
EXPORT_SYMBOL(strrchr);

/**
 * strstr - Find the first substring in a %NUL terminated string
 * @s1: The string to be searched
 * @s2: The string to search for
 */
char * strstr(const char * s1,const char * s2)
{
	int l1, l2;

	l2 = __strend(s2) - s2;
	if (!l2)
		return (char *) s1;
	l1 = __strend(s1) - s1;
	while (l1-- >= l2) {
		register unsigned long r2 asm("2") = (unsigned long) s1;
		register unsigned long r3 asm("3") = (unsigned long) l2;
		register unsigned long r4 asm("4") = (unsigned long) s2;
		register unsigned long r5 asm("5") = (unsigned long) l2;
		int cc;

		asm volatile ("0: clcle %1,%3,0\n"
			      "   jo    0b\n"
			      "   ipm   %0\n"
			      "   srl   %0,28"
			      : "=&d" (cc), "+a" (r2), "+a" (r3),
			        "+a" (r4), "+a" (r5) : : "cc" );
		if (!cc)
			return (char *) s1;
		s1++;
	}
	return NULL;
}
EXPORT_SYMBOL(strstr);

/**
 * memchr - Find a character in an area of memory.
 * @s: The memory area
 * @c: The byte to search for
 * @n: The size of the area.
 *
 * returns the address of the first occurrence of @c, or %NULL
 * if @c is not found
 */
void *memchr(const void *s, int c, size_t n)
{
	register int r0 asm("0") = (char) c;
	const void *ret = s + n;

	asm volatile ("0: srst  %0,%1\n"
		      "   jo    0b\n"
		      "   jl	1f\n"
		      "   la    %0,0\n"
		      "1:"
		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
	return (void *) ret;
}
EXPORT_SYMBOL(memchr);

/**
 * memcmp - Compare two areas of memory
 * @cs: One area of memory
 * @ct: Another area of memory
 * @count: The size of the area.
 */
int memcmp(const void *cs, const void *ct, size_t n)
{
	register unsigned long r2 asm("2") = (unsigned long) cs;
	register unsigned long r3 asm("3") = (unsigned long) n;
	register unsigned long r4 asm("4") = (unsigned long) ct;
	register unsigned long r5 asm("5") = (unsigned long) n;
	int ret;

	asm volatile ("0: clcle %1,%3,0\n"
		      "   jo    0b\n"
		      "   ipm   %0\n"
		      "   srl   %0,28"
		      : "=&d" (ret), "+a" (r2), "+a" (r3), "+a" (r4), "+a" (r5)
		      : : "cc" );
	if (ret)
		ret = *(char *) r2 - *(char *) r4;
	return ret;
}
EXPORT_SYMBOL(memcmp);

/**
 * memscan - Find a character in an area of memory.
 * @s: The memory area
 * @c: The byte to search for
 * @n: The size of the area.
 *
 * returns the address of the first occurrence of @c, or 1 byte past
 * the area if @c is not found
 */
void *memscan(void *s, int c, size_t n)
{
	register int r0 asm("0") = (char) c;
	const void *ret = s + n;

	asm volatile ("0: srst  %0,%1\n"
		      "   jo    0b\n"
		      : "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
	return (void *) ret;
}
EXPORT_SYMBOL(memscan);

/**
 * memcpy - Copy one area of memory to another
 * @dest: Where to copy to
 * @src: Where to copy from
 * @n: The size of the area.
 *
 * returns a pointer to @dest
 */
void *memcpy(void *dest, const void *src, size_t n)
{
	return __builtin_memcpy(dest, src, n);
}
EXPORT_SYMBOL(memcpy);

/**
 * memset - Fill a region of memory with the given value
 * @s: Pointer to the start of the area.
 * @c: The byte to fill the area with
 * @n: The size of the area.
 *
 * returns a pointer to @s
 */
void *memset(void *s, int c, size_t n)
{
	char *xs;

	if (c == 0)
		return __builtin_memset(s, 0, n);

	xs = (char *) s;
	if (n > 0)
		do {
			*xs++ = c;
		} while (--n > 0);
	return s;
}
EXPORT_SYMBOL(memset);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/s390/lib/string.c
	3	* Optimized string functions
	4	*
	5	* S390 version
	6	* Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
	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/module.h>
	14
	15	/*
	16	* Helper functions to find the end of a string
	17	*/
	18	static inline char __strend(const char s)
	19	{
	20	register unsigned long r0 asm("0") = 0;
	21
	22	asm volatile ("0: srst %0,%1\n"
	23	" jo 0b"
	24	: "+d" (r0), "+a" (s) : : "cc" );
	25	return (char *) r0;
	26	}
	27
	28	static inline char __strnend(const char s, size_t n)
	29	{
	30	register unsigned long r0 asm("0") = 0;
	31	const char *p = s + n;
	32
	33	asm volatile ("0: srst %0,%1\n"
	34	" jo 0b"
	35	: "+d" (p), "+a" (s) : "d" (r0) : "cc" );
	36	return (char *) p;
	37	}
	38
	39	/**
	40	* strlen - Find the length of a string
	41	* @s: The string to be sized
	42	*
	43	* returns the length of @s
	44	*/
	45	size_t strlen(const char *s)
	46	{
1edad85b	47	#if __GNUC__ < 4
1da177e4	48	return __strend(s) - s;
1edad85b HC	49	#else
	50	return __builtin_strlen(s);
	51	#endif
1da177e4 LT	52	}
	53	EXPORT_SYMBOL(strlen);
	54
	55	/**
	56	* strnlen - Find the length of a length-limited string
	57	* @s: The string to be sized
	58	* @n: The maximum number of bytes to search
	59	*
	60	* returns the minimum of the length of @s and @n
	61	*/
	62	size_t strnlen(const char * s, size_t n)
	63	{
	64	return __strnend(s, n) - s;
	65	}
	66	EXPORT_SYMBOL(strnlen);
	67
	68	/**
	69	* strcpy - Copy a %NUL terminated string
	70	* @dest: Where to copy the string to
	71	* @src: Where to copy the string from
	72	*
	73	* returns a pointer to @dest
	74	*/
	75	char strcpy(char dest, const char *src)
	76	{
1edad85b	77	#if __GNUC__ < 4
1da177e4 LT	78	register int r0 asm("0") = 0;
	79	char *ret = dest;
	80
	81	asm volatile ("0: mvst %0,%1\n"
	82	" jo 0b"
	83	: "+&a" (dest), "+&a" (src) : "d" (r0)
	84	: "cc", "memory" );
	85	return ret;
1edad85b HC	86	#else
	87	return __builtin_strcpy(dest, src);
	88	#endif
1da177e4 LT	89	}
	90	EXPORT_SYMBOL(strcpy);
	91
	92	/**
	93	* strlcpy - Copy a %NUL terminated string into a sized buffer
	94	* @dest: Where to copy the string to
	95	* @src: Where to copy the string from
	96	* @size: size of destination buffer
	97	*
	98	* Compatible with *BSD: the result is always a valid
	99	* NUL-terminated string that fits in the buffer (unless,
	100	* of course, the buffer size is zero). It does not pad
	101	* out the result like strncpy() does.
	102	*/
	103	size_t strlcpy(char dest, const char src, size_t size)
	104	{
	105	size_t ret = __strend(src) - src;
	106
	107	if (size) {
	108	size_t len = (ret >= size) ? size-1 : ret;
	109	dest[len] = '\0';
	110	__builtin_memcpy(dest, src, len);
	111	}
	112	return ret;
	113	}
	114	EXPORT_SYMBOL(strlcpy);
	115
	116	/**
	117	* strncpy - Copy a length-limited, %NUL-terminated string
	118	* @dest: Where to copy the string to
	119	* @src: Where to copy the string from
	120	* @n: The maximum number of bytes to copy
	121	*
	122	* The result is not %NUL-terminated if the source exceeds
	123	* @n bytes.
	124	*/
	125	char strncpy(char dest, const char *src, size_t n)
	126	{
	127	size_t len = __strnend(src, n) - src;
	128	__builtin_memset(dest + len, 0, n - len);
	129	__builtin_memcpy(dest, src, len);
	130	return dest;
	131	}
	132	EXPORT_SYMBOL(strncpy);
	133
	134	/**
	135	* strcat - Append one %NUL-terminated string to another
	136	* @dest: The string to be appended to
	137	* @src: The string to append to it
	138	*
	139	* returns a pointer to @dest
	140	*/
	141	char strcat(char dest, const char *src)
	142	{
	143	register int r0 asm("0") = 0;
	144	unsigned long dummy;
	145	char *ret = dest;
	146
	147	asm volatile ("0: srst %0,%1\n"
	148	" jo 0b\n"
	149	"1: mvst %0,%2\n"
	150	" jo 1b"
	151	: "=&a" (dummy), "+a" (dest), "+a" (src)
	152	: "d" (r0), "0" (0UL) : "cc", "memory" );
153	return ret;
154	}
155	EXPORT_SYMBOL(strcat);
156
157	/**
158	* strlcat - Append a length-limited, %NUL-terminated string to another
159	* @dest: The string to be appended to
160	* @src: The string to append to it
161	* @n: The size of the destination buffer.
162	*/
163	size_t strlcat(char dest, const char src, size_t n)
164	{
165	size_t dsize = __strend(dest) - dest;
166	size_t len = __strend(src) - src;
167	size_t res = dsize + len;
168
169	if (dsize < n) {
170	dest += dsize;
171	n -= dsize;
172	if (len >= n)
173	len = n - 1;
174	dest[len] = '\0';
175	__builtin_memcpy(dest, src, len);
176	}
177	return res;
178	}
179	EXPORT_SYMBOL(strlcat);
180
181	/**
182	* strncat - Append a length-limited, %NUL-terminated string to another
183	* @dest: The string to be appended to
184	* @src: The string to append to it
185	* @n: The maximum numbers of bytes to copy
186	*
187	* returns a pointer to @dest
188	*
189	* Note that in contrast to strncpy, strncat ensures the result is
190	* terminated.
191	*/
192	char strncat(char dest, const char *src, size_t n)
193	{
194	size_t len = __strnend(src, n) - src;
195	char *p = __strend(dest);
196
197	p[len] = '\0';
198	__builtin_memcpy(p, src, len);
199	return dest;
200	}
201	EXPORT_SYMBOL(strncat);
202
203	/**
204	* strcmp - Compare two strings
205	* @cs: One string
206	* @ct: Another string
207	*
208	* returns 0 if @cs and @ct are equal,
209	* < 0 if @cs is less than @ct
210	* > 0 if @cs is greater than @ct
211	*/
212	int strcmp(const char cs, const char ct)
213	{
214	register int r0 asm("0") = 0;
215	int ret = 0;
216
217	asm volatile ("0: clst %2,%3\n"
218	" jo 0b\n"
219	" je 1f\n"
220	" ic %0,0(%2)\n"
221	" ic %1,0(%3)\n"
222	" sr %0,%1\n"
223	"1:"
224	: "+d" (ret), "+d" (r0), "+a" (cs), "+a" (ct)
225	: : "cc" );
226	return ret;
227	}
228	EXPORT_SYMBOL(strcmp);
229
230	/**
231	* strrchr - Find the last occurrence of a character in a string
232	* @s: The string to be searched
233	* @c: The character to search for
234	*/
235	char * strrchr(const char * s, int c)
236	{
237	size_t len = __strend(s) - s;
238
239	if (len)
240	do {
241	if (s[len] == (char) c)
242	return (char *) s + len;
243	} while (--len > 0);
d2c993d8	244	return NULL;
1da177e4 LT	245	}
	246	EXPORT_SYMBOL(strrchr);
	247
	248	/**
	249	* strstr - Find the first substring in a %NUL terminated string
	250	* @s1: The string to be searched
	251	* @s2: The string to search for
	252	*/
	253	char * strstr(const char * s1,const char * s2)
	254	{
	255	int l1, l2;
	256
	257	l2 = __strend(s2) - s2;
	258	if (!l2)
	259	return (char *) s1;
	260	l1 = __strend(s1) - s1;
	261	while (l1-- >= l2) {
	262	register unsigned long r2 asm("2") = (unsigned long) s1;
	263	register unsigned long r3 asm("3") = (unsigned long) l2;
	264	register unsigned long r4 asm("4") = (unsigned long) s2;
	265	register unsigned long r5 asm("5") = (unsigned long) l2;
	266	int cc;
	267
	268	asm volatile ("0: clcle %1,%3,0\n"
	269	" jo 0b\n"
	270	" ipm %0\n"
	271	" srl %0,28"
	272	: "=&d" (cc), "+a" (r2), "+a" (r3),
	273	"+a" (r4), "+a" (r5) : : "cc" );
	274	if (!cc)
	275	return (char *) s1;
	276	s1++;
	277	}
d2c993d8	278	return NULL;
1da177e4 LT	279	}
	280	EXPORT_SYMBOL(strstr);
	281
	282	/**
	283	* memchr - Find a character in an area of memory.
	284	* @s: The memory area
	285	* @c: The byte to search for
	286	* @n: The size of the area.
	287	*
	288	* returns the address of the first occurrence of @c, or %NULL
	289	* if @c is not found
	290	*/
	291	void memchr(const void s, int c, size_t n)
	292	{
	293	register int r0 asm("0") = (char) c;
	294	const void *ret = s + n;
	295
	296	asm volatile ("0: srst %0,%1\n"
	297	" jo 0b\n"
	298	" jl 1f\n"
	299	" la %0,0\n"
	300	"1:"
	301	: "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
	302	return (void *) ret;
	303	}
	304	EXPORT_SYMBOL(memchr);
	305
	306	/**
	307	* memcmp - Compare two areas of memory
	308	* @cs: One area of memory
	309	* @ct: Another area of memory
	310	* @count: The size of the area.
	311	*/
	312	int memcmp(const void cs, const void ct, size_t n)
	313	{
	314	register unsigned long r2 asm("2") = (unsigned long) cs;
	315	register unsigned long r3 asm("3") = (unsigned long) n;
	316	register unsigned long r4 asm("4") = (unsigned long) ct;
	317	register unsigned long r5 asm("5") = (unsigned long) n;
	318	int ret;
	319
	320	asm volatile ("0: clcle %1,%3,0\n"
	321	" jo 0b\n"
	322	" ipm %0\n"
	323	" srl %0,28"
	324	: "=&d" (ret), "+a" (r2), "+a" (r3), "+a" (r4), "+a" (r5)
	325	: : "cc" );
	326	if (ret)
	327	ret = (char ) r2 - (char ) r4;
	328	return ret;
	329	}
	330	EXPORT_SYMBOL(memcmp);
	331
	332	/**
	333	* memscan - Find a character in an area of memory.
	334	* @s: The memory area
	335	* @c: The byte to search for
	336	* @n: The size of the area.
	337	*
	338	* returns the address of the first occurrence of @c, or 1 byte past
	339	* the area if @c is not found
	340	*/
	341	void memscan(void s, int c, size_t n)
	342	{
343	register int r0 asm("0") = (char) c;
344	const void *ret = s + n;
345
346	asm volatile ("0: srst %0,%1\n"
347	" jo 0b\n"
348	: "+a" (ret), "+&a" (s) : "d" (r0) : "cc" );
349	return (void *) ret;
350	}
351	EXPORT_SYMBOL(memscan);
352
353	/**
354	* memcpy - Copy one area of memory to another
355	* @dest: Where to copy to
356	* @src: Where to copy from
357	* @n: The size of the area.
358	*
359	* returns a pointer to @dest
360	*/
361	void memcpy(void dest, const void *src, size_t n)
362	{
363	return __builtin_memcpy(dest, src, n);
364	}
365	EXPORT_SYMBOL(memcpy);
366
367	/**
368	* memset - Fill a region of memory with the given value
369	* @s: Pointer to the start of the area.
370	* @c: The byte to fill the area with
371	* @n: The size of the area.
372	*
373	* returns a pointer to @s
374	*/
375	void memset(void s, int c, size_t n)
376	{
377	char *xs;
378
379	if (c == 0)
380	return __builtin_memset(s, 0, n);
381
382	xs = (char *) s;
383	if (n > 0)
384	do {
385	*xs++ = c;
386	} while (--n > 0);
387	return s;
388	}
389	EXPORT_SYMBOL(memset);