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-rw-r--r--arch/s390/lib/string.c485
1 files changed, 485 insertions, 0 deletions
diff --git a/arch/s390/lib/string.c b/arch/s390/lib/string.c
new file mode 100644
index 000000000..32e0e6b1e
--- /dev/null
+++ b/arch/s390/lib/string.c
@@ -0,0 +1,485 @@
+// 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
+#ifndef __NO_FORTIFY
+# define __NO_FORTIFY
+#endif
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <asm/facility.h>
+#include <asm/asm.h>
+
+#define SYMBOL_FUNCTION_ALIAS(alias, name) \
+asm(".globl " __stringify(alias) "\n\t" \
+ ".set " __stringify(alias) "," __stringify(name))
+
+#ifdef __HAVE_ARCH_MEMMOVE
+noinstr void *__memmove(void *dest, const void *src, size_t n)
+{
+ const char *s = src;
+ char *d = dest;
+
+ if (!n)
+ return dest;
+ if ((d <= s || d >= s + n)) {
+ /* Forward copy */
+ while (n >= 256) {
+ asm volatile(
+ " mvc 0(256,%[d]),0(%[s])\n"
+ :
+ : [d] "a" (d), [s] "a" (s)
+ : "memory");
+ d += 256;
+ s += 256;
+ n -= 256;
+ }
+ if (n) {
+ asm volatile(
+ " exrl %[n],0f\n"
+ " j 1f\n"
+ "0: mvc 0(1,%[d]),0(%[s])\n"
+ "1:"
+ :
+ : [d] "a" (d), [s] "a" (s), [n] "a" (n - 1)
+ : "memory");
+ }
+ return dest;
+ }
+ /* Backward copy */
+ if (test_facility(61)) {
+ /* Use mvcrl instruction if available */
+ while (n >= 256) {
+ asm volatile(
+ " lghi %%r0,255\n"
+ " .insn sse,0xe50a00000000,%[d],%[s]\n"
+ : [d] "=Q" (*(d + n - 256))
+ : [s] "Q" (*(s + n - 256))
+ : "0", "memory");
+ n -= 256;
+ }
+ if (n) {
+ asm volatile(
+ " lgr %%r0,%[n]\n"
+ " .insn sse,0xe50a00000000,%[d],%[s]\n"
+ : [d] "=Q" (*d)
+ : [s] "Q" (*s), [n] "d" (n - 1)
+ : "0", "memory");
+ }
+ } else {
+ while (n--)
+ d[n] = s[n];
+ }
+ return dest;
+}
+SYMBOL_FUNCTION_ALIAS(memmove, __memmove);
+EXPORT_SYMBOL(__memmove);
+EXPORT_SYMBOL(memmove);
+#endif
+
+#ifdef __HAVE_ARCH_MEMSET
+noinstr void *__memset(void *s, int c, size_t n)
+{
+ char *xs = s;
+
+ if (!n)
+ return s;
+ if (!c) {
+ /* Clear memory */
+ while (n >= 256) {
+ asm volatile(
+ " xc 0(256,%[xs]),0(%[xs])"
+ :
+ : [xs] "a" (xs)
+ : "cc", "memory");
+ xs += 256;
+ n -= 256;
+ }
+ if (!n)
+ return s;
+ asm volatile(
+ " exrl %[n],0f\n"
+ " j 1f\n"
+ "0: xc 0(1,%[xs]),0(%[xs])\n"
+ "1:"
+ :
+ : [xs] "a" (xs), [n] "a" (n - 1)
+ : "cc", "memory");
+ } else {
+ /* Fill memory */
+ while (n >= 256) {
+ *xs = c;
+ asm volatile(
+ " mvc 1(255,%[xs]),0(%[xs])"
+ :
+ : [xs] "a" (xs)
+ : "memory");
+ xs += 256;
+ n -= 256;
+ }
+ if (!n)
+ return s;
+ *xs = c;
+ if (n == 1)
+ return s;
+ asm volatile(
+ " exrl %[n],0f\n"
+ " j 1f\n"
+ "0: mvc 1(1,%[xs]),0(%[xs])\n"
+ "1:"
+ :
+ : [xs] "a" (xs), [n] "a" (n - 2)
+ : "memory");
+ }
+ return s;
+}
+SYMBOL_FUNCTION_ALIAS(memset, __memset);
+EXPORT_SYMBOL(__memset);
+EXPORT_SYMBOL(memset);
+#endif
+
+#ifdef __HAVE_ARCH_MEMCPY
+noinstr void *__memcpy(void *dest, const void *src, size_t n)
+{
+ void *d = dest;
+
+ if (!n)
+ return d;
+ while (n >= 256) {
+ asm volatile(
+ " mvc 0(256,%[dest]),0(%[src])"
+ :
+ : [dest] "a" (dest), [src] "a" (src)
+ : "memory");
+ dest += 256;
+ src += 256;
+ n -= 256;
+ }
+ if (!n)
+ return d;
+ asm volatile(
+ " exrl %[n],1f\n"
+ " j 2f\n"
+ "1: mvc 0(1,%[dest]),0(%[src])\n"
+ "2:"
+ :
+ : [dest] "a" (dest), [src] "a" (src), [n] "a" (n - 1)
+ : "memory");
+ return d;
+}
+SYMBOL_FUNCTION_ALIAS(memcpy, __memcpy);
+EXPORT_SYMBOL(__memcpy);
+EXPORT_SYMBOL(memcpy);
+#endif
+
+#define DEFINE_MEMSET(_bits, _bytes, _type) \
+void *__memset##_bits(_type *s, _type v, size_t n) \
+{ \
+ _type *xs = s; \
+ \
+ if (!n) \
+ return s; \
+ while (n >= 256) { \
+ *xs = v; \
+ asm volatile( \
+ " mvc %[_b](256-%[_b],%[xs]),0(%[xs])\n" \
+ : \
+ : [xs] "a" (xs), [_b] "i" (_bytes) \
+ : "memory"); \
+ xs = (_type *)((char *)xs + 256); \
+ n -= 256; \
+ } \
+ if (!n) \
+ return s; \
+ *xs = v; \
+ if (n == _bytes) \
+ return s; \
+ n -= _bytes + 1; \
+ asm volatile( \
+ " exrl %[n],1f\n" \
+ " j 2f\n" \
+ "1: mvc %[_b](1,%[xs]),0(%[xs])\n" \
+ "2:" \
+ : \
+ : [n] "a" (n), [xs] "a" (xs), [_b] "i" (_bytes) \
+ : "memory"); \
+ return s; \
+} \
+EXPORT_SYMBOL(__memset##_bits)
+
+#ifdef __HAVE_ARCH_MEMSET16
+DEFINE_MEMSET(16, 2, uint16_t);
+#endif
+
+#ifdef __HAVE_ARCH_MEMSET32
+DEFINE_MEMSET(32, 4, uint32_t);
+#endif
+
+#ifdef __HAVE_ARCH_MEMSET64
+DEFINE_MEMSET(64, 8, uint64_t);
+#endif
+
+/*
+ * Helper functions to find the end of a string
+ */
+static inline char *__strend(const char *s)
+{
+ unsigned long e = 0;
+
+ asm volatile(
+ " lghi 0,0\n"
+ "0: srst %[e],%[s]\n"
+ " jo 0b"
+ : [e] "+&a" (e), [s] "+&a" (s)
+ :
+ : "cc", "memory", "0");
+ return (char *)e;
+}
+
+static inline char *__strnend(const char *s, size_t n)
+{
+ const char *p = s + n;
+
+ asm volatile(
+ " lghi 0,0\n"
+ "0: srst %[p],%[s]\n"
+ " jo 0b"
+ : [p] "+&d" (p), [s] "+&a" (s)
+ :
+ : "cc", "memory", "0");
+ 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
+
+/**
+ * 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)
+{
+ unsigned long dummy = 0;
+ char *ret = dest;
+
+ asm volatile(
+ " lghi 0,0\n"
+ "0: srst %[dummy],%[dest]\n"
+ " jo 0b\n"
+ "1: mvst %[dummy],%[src]\n"
+ " jo 1b"
+ : [dummy] "+&a" (dummy), [dest] "+&a" (dest), [src] "+&a" (src)
+ :
+ : "cc", "memory", "0");
+ return ret;
+}
+EXPORT_SYMBOL(strcat);
+#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
+ */
+#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)
+{
+ int ret = 0;
+
+ asm volatile(
+ " lghi 0,0\n"
+ "0: clst %[s1],%[s2]\n"
+ " jo 0b\n"
+ " je 1f\n"
+ " ic %[ret],0(%[s1])\n"
+ " ic 0,0(%[s2])\n"
+ " sr %[ret],0\n"
+ "1:"
+ : [ret] "+&d" (ret), [s1] "+&a" (s1), [s2] "+&a" (s2)
+ :
+ : "cc", "memory", "0");
+ return ret;
+}
+EXPORT_SYMBOL(strcmp);
+#endif
+
+static inline int clcle(const char *s1, unsigned long l1,
+ const char *s2, unsigned long l2)
+{
+ union register_pair r1 = { .even = (unsigned long)s1, .odd = l1, };
+ union register_pair r3 = { .even = (unsigned long)s2, .odd = l2, };
+ int cc;
+
+ asm volatile(
+ "0: clcle %[r1],%[r3],0\n"
+ " jo 0b\n"
+ CC_IPM(cc)
+ : CC_OUT(cc, cc), [r1] "+d" (r1.pair), [r3] "+d" (r3.pair)
+ :
+ : CC_CLOBBER_LIST("memory"));
+ return CC_TRANSFORM(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)
+{
+ const void *ret = s + n;
+
+ asm volatile(
+ " lgr 0,%[c]\n"
+ "0: srst %[ret],%[s]\n"
+ " jo 0b\n"
+ " jl 1f\n"
+ " la %[ret],0\n"
+ "1:"
+ : [ret] "+&a" (ret), [s] "+&a" (s)
+ : [c] "d" (c)
+ : "cc", "memory", "0");
+ 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)
+{
+ const void *ret = s + n;
+
+ asm volatile(
+ " lgr 0,%[c]\n"
+ "0: srst %[ret],%[s]\n"
+ " jo 0b"
+ : [ret] "+&a" (ret), [s] "+&a" (s)
+ : [c] "d" (c)
+ : "cc", "memory", "0");
+ return (void *)ret;
+}
+EXPORT_SYMBOL(memscan);
+#endif
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