summaryrefslogtreecommitdiff
path: root/arch/s390/lib/string.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/s390/lib/string.c')
-rw-r--r--arch/s390/lib/string.c381
1 files changed, 381 insertions, 0 deletions
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
new file mode 100644
index 000000000000..8240cc77e06e
--- /dev/null
+++ b/arch/s390/lib/string.c
@@ -0,0 +1,381 @@
+/*
+ * 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);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-29 08:19:14 +0000