arch/mips/lib/strlen_user.S

/*
 * 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) 1996, 1998, 1999, 2004 by Ralf Baechle
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Copyright (C) 2011 MIPS Technologies, Inc.
 */
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>

#define EX(insn,reg,addr,handler)                       \
9:	insn	reg, addr;				\
	.section __ex_table,"a";			\
	PTR	9b, handler;				\
	.previous

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 for error
 */
LEAF(__strlen_kernel_asm)
	LONG_L          v0, TI_ADDR_LIMIT($28)  # pointer ok?
	and             v0, a0
	bnez            v0, .Lfault

FEXPORT(__strlen_kernel_nocheck_asm)
	move            v0, a0
1:      EX(lbu, v1, (v0), .Lfault)
	PTR_ADDIU       v0, 1
	bnez            v1, 1b
	PTR_SUBU        v0, a0
	jr              ra
	END(__strlen_kernel_asm)

.Lfault:        move            v0, zero
	jr              ra

#ifdef CONFIG_EVA

LEAF(__strlen_user_asm)
	LONG_L          v0, TI_ADDR_LIMIT($28)  # pointer ok?
	and             v0, a0
	bnez            v0, .Lfault

FEXPORT(__strlen_user_nocheck_asm)
	move            v0, a0
	.set            eva
1:      EX(lbue, v1, (v0), .Lfault)
	PTR_ADDIU       v0, 1
	bnez            v1, 1b
	PTR_SUBU        v0, a0
	jr              ra
	END(__strlen_user_asm)

#endif