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>
10#include <asm/asm-offsets.h>
11#include <asm/regdef.h>
12
13#define EX(insn,reg,addr,handler)			\
149:	insn	reg, addr;				\
15	.section __ex_table,"a";			\
16	PTR	9b, handler;				\
17	.previous
18
19/*
20 * Return the size of a string including the ending NUL character up to a
21 * maximum of a1 or 0 in case of error.
22 *
23 * Note: for performance reasons we deliberately accept that a user may
24 *	 make strlen_user and strnlen_user access the first few KSEG0
25 *	 bytes.	 There's nothing secret there.	On 64-bit accessing beyond
26 *	 the maximum is a tad hairier ...
27 */
28	.macro __BUILD_STRNLEN_ASM func
29LEAF(__strnlen_\func\()_asm)
30	LONG_L		v0, TI_ADDR_LIMIT($28)	# pointer ok?
31	and		v0, a0
32	bnez		v0, .Lfault\@
33
34FEXPORT(__strnlen_\func\()_nocheck_asm)
35	move		v0, a0
36	PTR_ADDU	a1, a0			# stop pointer
371:
38#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
39	.set		noat
40	li		AT, 1
41#endif
42	beq		v0, a1, 1f		# limit reached?
43.ifeqs "\func", "kernel"
44	EX(lb, t0, (v0), .Lfault\@)
45.else
46	EX(lbe, t0, (v0), .Lfault\@)
47.endif
48	.set		noreorder
49	bnez		t0, 1b
501:
51#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
52	 PTR_ADDIU	v0, 1
53#else
54	 PTR_ADDU	v0, AT
55	.set		at
56#endif
57	.set		reorder
58	PTR_SUBU	v0, a0
59	jr		ra
60	END(__strnlen_\func\()_asm)
61
62.Lfault\@:
63	move		v0, zero
64	jr		ra
65	.endm
66
67#ifndef CONFIG_EVA
68	/* Set aliases */
69	.global __strnlen_user_asm
70	.global __strnlen_user_nocheck_asm
71	.set __strnlen_user_asm, __strnlen_kernel_asm
72	.set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm
73#endif
74
75__BUILD_STRNLEN_ASM kernel
76
77#ifdef CONFIG_EVA
78
79	.set push
80	.set eva
81__BUILD_STRNLEN_ASM user
82	.set pop
83#endif
84