[mirror_ubuntu-artful-kernel.git] / arch / mips / lib / strnlen_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.
 */
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/export.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 NUL character up to a
 * maximum of a1 or 0 in case of error.
 *
 * Note: for performance reasons we deliberately accept that a user may
 *	 make strlen_user and strnlen_user access the first few KSEG0
 *	 bytes.	 There's nothing secret there.	On 64-bit accessing beyond
 *	 the maximum is a tad hairier ...
 */
	.macro __BUILD_STRNLEN_ASM func
LEAF(__strnlen_\func\()_asm)
	LONG_L		v0, TI_ADDR_LIMIT($28)	# pointer ok?
	and		v0, a0
	bnez		v0, .Lfault\@

FEXPORT(__strnlen_\func\()_nocheck_asm)
	move		v0, a0
	PTR_ADDU	a1, a0			# stop pointer
1:
#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
	.set		noat
	li		AT, 1
#endif
	beq		v0, a1, 1f		# limit reached?
.ifeqs "\func", "kernel"
	EX(lb, t0, (v0), .Lfault\@)
.else
	EX(lbe, t0, (v0), .Lfault\@)
.endif
	.set		noreorder
	bnez		t0, 1b
1:
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
	 PTR_ADDIU	v0, 1
#else
	 PTR_ADDU	v0, AT
	.set		at
#endif
	.set		reorder
	PTR_SUBU	v0, a0
	jr		ra
	END(__strnlen_\func\()_asm)

.Lfault\@:
	move		v0, zero
	jr		ra
	.endm

#ifndef CONFIG_EVA
	/* Set aliases */
	.global __strnlen_user_asm
	.global __strnlen_user_nocheck_asm
	.set __strnlen_user_asm, __strnlen_kernel_asm
	.set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm
EXPORT_SYMBOL(__strnlen_user_asm)
EXPORT_SYMBOL(__strnlen_user_nocheck_asm)
#endif

__BUILD_STRNLEN_ASM kernel
EXPORT_SYMBOL(__strnlen_kernel_asm)
EXPORT_SYMBOL(__strnlen_kernel_nocheck_asm)

#ifdef CONFIG_EVA

	.set push
	.set eva
__BUILD_STRNLEN_ASM user
	.set pop
EXPORT_SYMBOL(__strnlen_user_asm)
EXPORT_SYMBOL(__strnlen_user_nocheck_asm)
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
	7	* Copyright (c) 1999 Silicon Graphics, Inc.
	8	*/
	9	#include <asm/asm.h>
048eb582	10	#include <asm/asm-offsets.h>
d6cb6715	11	#include <asm/export.h>
1da177e4 LT	12	#include <asm/regdef.h>
	13
	14	#define EX(insn,reg,addr,handler) \
	15	9: insn reg, addr; \
	16	.section __ex_table,"a"; \
	17	PTR 9b, handler; \
	18	.previous
	19
	20	/*
25985edc	21	* Return the size of a string including the ending NUL character up to a
1da177e4 LT	22	* maximum of a1 or 0 in case of error.
	23	*
	24	* Note: for performance reasons we deliberately accept that a user may
70342287 RB	25	* make strlen_user and strnlen_user access the first few KSEG0
	26	* bytes. There's nothing secret there. On 64-bit accessing beyond
	27	* the maximum is a tad hairier ...
1da177e4	28	*/
c48be43e MC	29	.macro __BUILD_STRNLEN_ASM func
c48be43e MC	30	LEAF(__strnlen_\func\()_asm)
1da177e4 LT	31	LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
1da177e4 LT	32	and v0, a0
c48be43e	33	bnez v0, .Lfault\@
1da177e4	34
c48be43e	35	FEXPORT(__strnlen_\func\()_nocheck_asm)
1da177e4 LT	36	move v0, a0
1da177e4 LT	37	PTR_ADDU a1, a0 # stop pointer
c4fca4fd MR	38	1:
	39	#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
	40	.set noat
	41	li AT, 1
	42	#endif
	43	beq v0, a1, 1f # limit reached?
4968db4b	44	.ifeqs "\func", "kernel"
c48be43e	45	EX(lb, t0, (v0), .Lfault\@)
4968db4b MC	46	.else
	47	EX(lbe, t0, (v0), .Lfault\@)
	48	.endif
00977610	49	.set noreorder
1da177e4	50	bnez t0, 1b
c4fca4fd MR	51	1:
	52	#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
	53	PTR_ADDIU v0, 1
	54	#else
	55	PTR_ADDU v0, AT
	56	.set at
	57	#endif
00977610 RB	58	.set reorder
00977610 RB	59	PTR_SUBU v0, a0
1da177e4	60	jr ra
c48be43e	61	END(__strnlen_\func\()_asm)
1da177e4	62
c48be43e	63	.Lfault\@:
c5ec1983	64	move v0, zero
1da177e4	65	jr ra
c48be43e MC	66	.endm
c48be43e MC	67
4968db4b MC	68	#ifndef CONFIG_EVA
	69	/* Set aliases */
	70	.global __strnlen_user_asm
	71	.global __strnlen_user_nocheck_asm
	72	.set __strnlen_user_asm, __strnlen_kernel_asm
	73	.set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm
b668970e AB	74	EXPORT_SYMBOL(__strnlen_user_asm)
b668970e AB	75	EXPORT_SYMBOL(__strnlen_user_nocheck_asm)
4968db4b MC	76	#endif
	77
	78	__BUILD_STRNLEN_ASM kernel
b668970e AB	79	EXPORT_SYMBOL(__strnlen_kernel_asm)
b668970e AB	80	EXPORT_SYMBOL(__strnlen_kernel_nocheck_asm)
4968db4b MC	81
	82	#ifdef CONFIG_EVA
	83
	84	.set push
	85	.set eva
c48be43e	86	__BUILD_STRNLEN_ASM user
4968db4b	87	.set pop
b668970e AB	88	EXPORT_SYMBOL(__strnlen_user_asm)
b668970e AB	89	EXPORT_SYMBOL(__strnlen_user_nocheck_asm)
4968db4b	90	#endif