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-rw-r--r--arch/s390/lib/string.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
new file mode 100644
index 000000000..db4e539d8
--- /dev/null
+++ b/arch/s390/lib/string.c
@@ -0,0 +1,371 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/string.h>
+#include <linux/export.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", "memory");
+ 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", "memory");
+ return (char *) p;
+}
+
+/**
+ * strlen - Find the length of a string
+ * @s: The string to be sized
+ *
+ * returns the length of @s
+ */
+#ifdef __HAVE_ARCH_STRLEN
+size_t strlen(const char *s)
+{
+ return __strend(s) - s;
+}
+EXPORT_SYMBOL(strlen);
+#endif
+
+/**
+ * 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
+ */
+#ifdef __HAVE_ARCH_STRNLEN
+size_t strnlen(const char *s, size_t n)
+{
+ return __strnend(s, n) - s;
+}
+EXPORT_SYMBOL(strnlen);
+#endif
+
+/**
+ * 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
+ */
+#ifdef __HAVE_ARCH_STRCPY
+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);
+#endif
+
+/**
+ * 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.
+ */
+#ifdef __HAVE_ARCH_STRLCPY
+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);
+#endif
+
+/**
+ * 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.
+ */
+#ifdef __HAVE_ARCH_STRNCPY
+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);
+#endif
+
+/**
+ * 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
+ */
+#ifdef __HAVE_ARCH_STRCAT
+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);
+#endif
+
+/**
+ * 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.
+ */
+#ifdef __HAVE_ARCH_STRLCAT
+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);
+#endif
+
+/**
+ * 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.
+ */
+#ifdef __HAVE_ARCH_STRNCAT
+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);
+#endif
+
+/**
+ * strcmp - Compare two strings
+ * @s1: One string
+ * @s2: Another string
+ *
+ * returns 0 if @s1 and @s2 are equal,
+ * < 0 if @s1 is less than @s2
+ * > 0 if @s1 is greater than @s2
+ */
+#ifdef __HAVE_ARCH_STRCMP
+int strcmp(const char *s1, const char *s2)
+{
+ 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" (s1), "+a" (s2)
+ : : "cc", "memory");
+ return ret;
+}
+EXPORT_SYMBOL(strcmp);
+#endif
+
+/**
+ * strrchr - Find the last occurrence of a character in a string
+ * @s: The string to be searched
+ * @c: The character to search for
+ */
+#ifdef __HAVE_ARCH_STRRCHR
+char *strrchr(const char *s, int c)
+{
+ ssize_t len = __strend(s) - s;
+
+ do {
+ if (s[len] == (char)c)
+ return (char *)s + len;
+ } while (--len >= 0);
+ return NULL;
+}
+EXPORT_SYMBOL(strrchr);
+#endif
+
+static inline int clcle(const char *s1, unsigned long l1,
+ const char *s2, unsigned long l2)
+{
+ register unsigned long r2 asm("2") = (unsigned long) s1;
+ register unsigned long r3 asm("3") = (unsigned long) l1;
+ 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", "memory");
+ return cc;
+}
+
+/**
+ * strstr - Find the first substring in a %NUL terminated string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ */
+#ifdef __HAVE_ARCH_STRSTR
+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) {
+ int cc;
+
+ cc = clcle(s1, l2, s2, l2);
+ if (!cc)
+ return (char *) s1;
+ s1++;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(strstr);
+#endif
+
+/**
+ * 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
+ */
+#ifdef __HAVE_ARCH_MEMCHR
+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", "memory");
+ return (void *) ret;
+}
+EXPORT_SYMBOL(memchr);
+#endif
+
+/**
+ * memcmp - Compare two areas of memory
+ * @s1: One area of memory
+ * @s2: Another area of memory
+ * @n: The size of the area.
+ */
+#ifdef __HAVE_ARCH_MEMCMP
+int memcmp(const void *s1, const void *s2, size_t n)
+{
+ int ret;
+
+ ret = clcle(s1, n, s2, n);
+ if (ret)
+ ret = ret == 1 ? -1 : 1;
+ return ret;
+}
+EXPORT_SYMBOL(memcmp);
+#endif
+
+/**
+ * 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
+ */
+#ifdef __HAVE_ARCH_MEMSCAN
+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", "memory");
+ return (void *) ret;
+}
+EXPORT_SYMBOL(memscan);
+#endif
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