/* *  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){	return __strend(s) - s;}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){	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;}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 0;}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 0;}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);