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 by Ralf Baechle
7 * Copyright (c) 1999 Silicon Graphics, Inc.
8 */
9#include <asm/asm.h>
10#include <asm/offset.h>
11#include <asm/regdef.h>
12#include <asm/sgidefs.h>
13
14#define EX(insn,reg,addr,handler)			\
159:	insn	reg, addr;				\
16	.section __ex_table,"a";			\
17	PTR	9b, handler;				\
18	.previous
19
20/*
21 * Return the size of a string (including the ending 0)
22 *
23 * Return 0 for error, len of string but at max a1 otherwise
24 *
25 * Note: for performance reasons we deliberately accept that a user may
26 *       make strlen_user and strnlen_user access the first few KSEG0
27 *       bytes.  There's nothing secret there ...
28 */
29LEAF(__strnlen_user_asm)
30	LONG_L		v0, THREAD_CURDS($28)	# pointer ok?
31	and		v0, a0
32	bnez		v0, fault
33
34FEXPORT(__strnlen_user_nocheck_asm)
35	move		v0, a0
36	PTR_ADDU	a1, a0			# stop pointer
37	.set		noreorder
381:	beq		v0, a1, 1f		# limit reached?
39	 PTR_ADDIU	v0, 1
40	.set		reorder
41	EX(lb, t0, -1(v0), fault)
42	bnez		t0, 1b
431:	PTR_SUBU	v0, a0
44	jr		ra
45	END(__strnlen_user_asm)
46
47fault:	move		v0, zero
48	jr		ra
49