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// 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_MEMMOVEnoinstr 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_MEMSETnoinstr 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_MEMCPYnoinstr 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_MEMSET16DEFINE_MEMSET(16, 2, uint16_t);#endif #ifdef __HAVE_ARCH_MEMSET32DEFINE_MEMSET(32, 4, uint32_t);#endif #ifdef __HAVE_ARCH_MEMSET64DEFINE_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_STRLENsize_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_STRNLENsize_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_STRCATchar *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_STRNCATchar *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_STRCMPint 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_STRSTRchar *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_MEMCHRvoid *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_MEMCMPint 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_MEMSCANvoid *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