Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  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 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);