1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Returns 0 if exception before NUL or reaching the supplied limit (N),
4  * a value greater than N if the string is longer than the limit, else
5  * strlen.
6  *
7  * Inputs:
8  *	in0:	address of buffer
9  *	in1:	string length limit N
10  * Outputs:
11  *	r8:	0 in case of fault, strlen(buffer)+1 otherwise
12  *
13  * Copyright (C) 1999, 2001 David Mosberger-Tang <davidm@hpl.hp.com>
14  */
15 
16 #include <asm/asmmacro.h>
17 #include <asm/export.h>
18 
19 GLOBAL_ENTRY(__strnlen_user)
20 	.prologue
21 	alloc r2=ar.pfs,2,0,0,0
22 	.save ar.lc, r16
23 	mov r16=ar.lc			// preserve ar.lc
24 
25 	.body
26 
27 	add r3=-1,in1
28 	;;
29 	mov ar.lc=r3
30 	mov r9=0
31 	;;
32 	// XXX braindead strlen loop---this needs to be optimized
33 .Loop1:
34 	EXCLR(.Lexit, ld1 r8=[in0],1)
35 	add r9=1,r9
36 	;;
37 	cmp.eq p6,p0=r8,r0
38 (p6)	br.cond.dpnt .Lexit
39 	br.cloop.dptk.few .Loop1
40 
41 	add r9=1,in1			// NUL not found---return N+1
42 	;;
43 .Lexit:
44 	mov r8=r9
45 	mov ar.lc=r16			// restore ar.lc
46 	br.ret.sptk.many rp
47 END(__strnlen_user)
48 EXPORT_SYMBOL(__strnlen_user)
49