xref: /OK3568_Linux_fs/kernel/arch/openrisc/lib/string.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0-or-later */
2*4882a593Smuzhiyun/*
3*4882a593Smuzhiyun * OpenRISC string.S
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Linux architectural port borrowing liberally from similar works of
6*4882a593Smuzhiyun * others.  All original copyrights apply as per the original source
7*4882a593Smuzhiyun * declaration.
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun * Modifications for the OpenRISC architecture:
10*4882a593Smuzhiyun * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11*4882a593Smuzhiyun * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12*4882a593Smuzhiyun */
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun#include <linux/linkage.h>
15*4882a593Smuzhiyun#include <asm/errno.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun	/*
18*4882a593Smuzhiyun	 * this can be optimized by doing gcc inline assemlby with
19*4882a593Smuzhiyun	 * proper constraints (no need to save args registers...)
20*4882a593Smuzhiyun	 *
21*4882a593Smuzhiyun	 */
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun/*
25*4882a593Smuzhiyun *
26*4882a593Smuzhiyun * int __copy_tofrom_user(void *to, const void *from, unsigned long size);
27*4882a593Smuzhiyun *
28*4882a593Smuzhiyun * NOTE: it returns number of bytes NOT copied !!!
29*4882a593Smuzhiyun *
30*4882a593Smuzhiyun */
31*4882a593Smuzhiyun	.global	__copy_tofrom_user
32*4882a593Smuzhiyun__copy_tofrom_user:
33*4882a593Smuzhiyun	l.addi  r1,r1,-12
34*4882a593Smuzhiyun	l.sw    0(r1),r6
35*4882a593Smuzhiyun	l.sw    4(r1),r4
36*4882a593Smuzhiyun	l.sw    8(r1),r3
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun	l.addi  r11,r5,0
39*4882a593Smuzhiyun2:  	l.sfeq  r11,r0
40*4882a593Smuzhiyun	l.bf    1f
41*4882a593Smuzhiyun	l.addi  r11,r11,-1
42*4882a593Smuzhiyun8:    	l.lbz   r6,0(r4)
43*4882a593Smuzhiyun9:    	l.sb    0(r3),r6
44*4882a593Smuzhiyun	l.addi  r3,r3,1
45*4882a593Smuzhiyun	l.j     2b
46*4882a593Smuzhiyun	l.addi  r4,r4,1
47*4882a593Smuzhiyun1:
48*4882a593Smuzhiyun	l.addi  r11,r11,1               // r11 holds the return value
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun	l.lwz   r6,0(r1)
51*4882a593Smuzhiyun	l.lwz   r4,4(r1)
52*4882a593Smuzhiyun	l.lwz   r3,8(r1)
53*4882a593Smuzhiyun	l.jr    r9
54*4882a593Smuzhiyun	l.addi  r1,r1,12
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun	.section .fixup, "ax"
57*4882a593Smuzhiyun99:
58*4882a593Smuzhiyun		l.j     1b
59*4882a593Smuzhiyun		l.nop
60*4882a593Smuzhiyun	.previous
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun	.section __ex_table, "a"
63*4882a593Smuzhiyun		.long 8b, 99b		// read fault
64*4882a593Smuzhiyun		.long 9b, 99b		// write fault
65*4882a593Smuzhiyun	.previous
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun/*
68*4882a593Smuzhiyun * unsigned long clear_user(void *addr, unsigned long size) ;
69*4882a593Smuzhiyun *
70*4882a593Smuzhiyun * NOTE: it returns number of bytes NOT cleared !!!
71*4882a593Smuzhiyun */
72*4882a593Smuzhiyun	.global	__clear_user
73*4882a593Smuzhiyun__clear_user:
74*4882a593Smuzhiyun	l.addi  r1,r1,-8
75*4882a593Smuzhiyun	l.sw    0(r1),r4
76*4882a593Smuzhiyun	l.sw    4(r1),r3
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun2:	l.sfeq	r4,r0
79*4882a593Smuzhiyun	l.bf	1f
80*4882a593Smuzhiyun	l.addi	r4,r4,-1
81*4882a593Smuzhiyun9:	l.sb	0(r3),r0
82*4882a593Smuzhiyun	l.j	2b
83*4882a593Smuzhiyun	l.addi  r3,r3,1
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun1:
86*4882a593Smuzhiyun	l.addi  r11,r4,1
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun	l.lwz	r4,0(r1)
89*4882a593Smuzhiyun	l.lwz	r3,4(r1)
90*4882a593Smuzhiyun	l.jr	r9
91*4882a593Smuzhiyun	l.addi	r1,r1,8
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun	.section .fixup, "ax"
94*4882a593Smuzhiyun99:
95*4882a593Smuzhiyun		l.j     1b
96*4882a593Smuzhiyun		l.nop
97*4882a593Smuzhiyun	.previous
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun	.section __ex_table, "a"
100*4882a593Smuzhiyun		.long 9b, 99b		// write fault
101*4882a593Smuzhiyun	.previous
102