blob: 92b63f20ec05fd71a13ea8d7c905d14451e105b1 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Sam Ravnborg048eb582005-09-09 22:32:31 +020010#include <asm/asm-offsets.h>
Paul Burtond6cb6712016-11-07 11:14:14 +000011#include <asm/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <asm/regdef.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/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -030021 * Return the size of a string including the ending NUL character up to a
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 * maximum of a1 or 0 in case of error.
23 *
24 * Note: for performance reasons we deliberately accept that a user may
Ralf Baechle70342282013-01-22 12:59:30 +010025 * 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 ...
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 */
Thomas Bogendoerfer04324f42021-04-01 14:56:37 +020029LEAF(__strnlen_user_asm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 move v0, a0
31 PTR_ADDU a1, a0 # stop pointer
Maciej W. Rozyckic4fca4f2015-05-28 17:46:49 +0100321:
33#ifdef CONFIG_CPU_DADDI_WORKAROUNDS
34 .set noat
35 li AT, 1
36#endif
37 beq v0, a1, 1f # limit reached?
Thomas Bogendoerfer04324f42021-04-01 14:56:37 +020038#ifdef CONFIG_EVA
39 .set push
40 .set eva
41 EX(lbe, t0, (v0), .Lfault)
42 .set pop
43#else
44 EX(lb, t0, (v0), .Lfault)
45#endif
Ralf Baechle00977612014-11-04 11:54:29 +010046 .set noreorder
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 bnez t0, 1b
Maciej W. Rozyckic4fca4f2015-05-28 17:46:49 +0100481:
49#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
50 PTR_ADDIU v0, 1
51#else
52 PTR_ADDU v0, AT
53 .set at
54#endif
Ralf Baechle00977612014-11-04 11:54:29 +010055 .set reorder
56 PTR_SUBU v0, a0
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 jr ra
Thomas Bogendoerfer04324f42021-04-01 14:56:37 +020058 END(__strnlen_user_asm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
Thomas Bogendoerfer04324f42021-04-01 14:56:37 +020060.Lfault:
Ralf Baechlec5ec1982008-01-29 10:14:59 +000061 move v0, zero
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 jr ra
Markos Chandrasc48be432014-01-02 16:19:49 +000063
Thomas Bogendoerfer04324f42021-04-01 14:56:37 +020064 EXPORT_SYMBOL(__strnlen_user_asm)