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Diffstat (limited to 'arch/s390/lib/string.c')
| -rw-r--r-- | arch/s390/lib/string.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c new file mode 100644 index 000000000..b647d5ff0 --- /dev/null +++ b/arch/s390/lib/string.c @@ -0,0 +1,342 @@ +/* + * Optimized string functions + * + * S390 version + * Copyright IBM Corp. 2004 + * 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'; + 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; + memset(dest + len, 0, n - len); + 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'; + 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'; + 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); |