xref: /kernel/linux/linux-6.6/arch/xtensa/include/asm/string.h (revision 62306a36)

/*
 * include/asm-xtensa/string.h
 *
 * These trivial string functions are considered part of the public domain.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2005 Tensilica Inc.
 */

/* We should optimize these. See arch/xtensa/lib/strncpy_user.S */

#ifndef _XTENSA_STRING_H
#define _XTENSA_STRING_H

#define __HAVE_ARCH_STRCPY
static inline char *strcpy(char *__dest, const char *__src)
{
	register char *__xdest = __dest;
	unsigned long __dummy;

	__asm__ __volatile__("1:\n\t"
		"l8ui	%2, %1, 0\n\t"
		"s8i	%2, %0, 0\n\t"
		"addi	%1, %1, 1\n\t"
		"addi	%0, %0, 1\n\t"
		"bnez	%2, 1b\n\t"
		: "=r" (__dest), "=r" (__src), "=&r" (__dummy)
		: "0" (__dest), "1" (__src)
		: "memory");

	return __xdest;
}

#define __HAVE_ARCH_STRNCPY
static inline char *strncpy(char *__dest, const char *__src, size_t __n)
{
	register char *__xdest = __dest;
	unsigned long __dummy;

	if (__n == 0)
		return __xdest;

	__asm__ __volatile__(
		"1:\n\t"
		"l8ui	%2, %1, 0\n\t"
		"s8i	%2, %0, 0\n\t"
		"addi	%1, %1, 1\n\t"
		"addi	%0, %0, 1\n\t"
		"beqz	%2, 2f\n\t"
		"bne	%1, %5, 1b\n"
		"2:"
		: "=r" (__dest), "=r" (__src), "=&r" (__dummy)
		: "0" (__dest), "1" (__src), "r" ((uintptr_t)__src+__n)
		: "memory");

	return __xdest;
}

#define __HAVE_ARCH_STRCMP
static inline int strcmp(const char *__cs, const char *__ct)
{
	register int __res;
	unsigned long __dummy;

	__asm__ __volatile__(
		"1:\n\t"
		"l8ui	%3, %1, 0\n\t"
		"addi	%1, %1, 1\n\t"
		"l8ui	%2, %0, 0\n\t"
		"addi	%0, %0, 1\n\t"
		"beqz	%2, 2f\n\t"
		"beq	%2, %3, 1b\n"
		"2:\n\t"
		"sub	%2, %2, %3"
		: "=r" (__cs), "=r" (__ct), "=&r" (__res), "=&r" (__dummy)
		: "0" (__cs), "1" (__ct));

	return __res;
}

#define __HAVE_ARCH_STRNCMP
static inline int strncmp(const char *__cs, const char *__ct, size_t __n)
{
	register int __res;
	unsigned long __dummy;

	__asm__ __volatile__(
		"mov	%2, %3\n"
		"1:\n\t"
		"beq	%0, %6, 2f\n\t"
		"l8ui	%3, %1, 0\n\t"
		"addi	%1, %1, 1\n\t"
		"l8ui	%2, %0, 0\n\t"
		"addi	%0, %0, 1\n\t"
		"beqz	%2, 2f\n\t"
		"beqz	%3, 2f\n\t"
		"beq	%2, %3, 1b\n"
		"2:\n\t"
		"sub	%2, %2, %3"
		: "=r" (__cs), "=r" (__ct), "=&r" (__res), "=&r" (__dummy)
		: "0" (__cs), "1" (__ct), "r" ((uintptr_t)__cs+__n));

	return __res;
}

#define __HAVE_ARCH_MEMSET
extern void *memset(void *__s, int __c, size_t __count);
extern void *__memset(void *__s, int __c, size_t __count);

#define __HAVE_ARCH_MEMCPY
extern void *memcpy(void *__to, __const__ void *__from, size_t __n);
extern void *__memcpy(void *__to, __const__ void *__from, size_t __n);

#define __HAVE_ARCH_MEMMOVE
extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
extern void *__memmove(void *__dest, __const__ void *__src, size_t __n);

#if defined(CONFIG_KASAN) && !defined(__SANITIZE_ADDRESS__)

/*
 * For files that are not instrumented (e.g. mm/slub.c) we
 * should use not instrumented version of mem* functions.
 */

#define memcpy(dst, src, len) __memcpy(dst, src, len)
#define memmove(dst, src, len) __memmove(dst, src, len)
#define memset(s, c, n) __memset(s, c, n)

#ifndef __NO_FORTIFY
#define __NO_FORTIFY /* FORTIFY_SOURCE uses __builtin_memcpy, etc. */
#endif
#endif

#endif	/* _XTENSA_STRING_H */