xref: /openbmc/linux/arch/ia64/lib/strnlen_user.S (revision e58e871b)
1/*
2 * Returns 0 if exception before NUL or reaching the supplied limit (N),
3 * a value greater than N if the string is longer than the limit, else
4 * strlen.
5 *
6 * Inputs:
7 *	in0:	address of buffer
8 *	in1:	string length limit N
9 * Outputs:
10 *	r8:	0 in case of fault, strlen(buffer)+1 otherwise
11 *
12 * Copyright (C) 1999, 2001 David Mosberger-Tang <davidm@hpl.hp.com>
13 */
14
15#include <asm/asmmacro.h>
16#include <asm/export.h>
17
18GLOBAL_ENTRY(__strnlen_user)
19	.prologue
20	alloc r2=ar.pfs,2,0,0,0
21	.save ar.lc, r16
22	mov r16=ar.lc			// preserve ar.lc
23
24	.body
25
26	add r3=-1,in1
27	;;
28	mov ar.lc=r3
29	mov r9=0
30	;;
31	// XXX braindead strlen loop---this needs to be optimized
32.Loop1:
33	EXCLR(.Lexit, ld1 r8=[in0],1)
34	add r9=1,r9
35	;;
36	cmp.eq p6,p0=r8,r0
37(p6)	br.cond.dpnt .Lexit
38	br.cloop.dptk.few .Loop1
39
40	add r9=1,in1			// NUL not found---return N+1
41	;;
42.Lexit:
43	mov r8=r9
44	mov ar.lc=r16			// restore ar.lc
45	br.ret.sptk.many rp
46END(__strnlen_user)
47EXPORT_SYMBOL(__strnlen_user)
48