Merge branches 'x86/amd', 'x86/vt-d', 'arm/exynos', 'arm/mediatek' and 'arm/renesas...
[deliverable/linux.git] / arch / arm / lib / clear_user.S
1 /*
2 * linux/arch/arm/lib/clear_user.S
3 *
4 * Copyright (C) 1995, 1996,1997,1998 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/linkage.h>
11 #include <asm/assembler.h>
12 #include <asm/unwind.h>
13
14 .text
15
16 /* Prototype: unsigned long arm_clear_user(void *addr, size_t sz)
17 * Purpose : clear some user memory
18 * Params : addr - user memory address to clear
19 * : sz - number of bytes to clear
20 * Returns : number of bytes NOT cleared
21 */
22 ENTRY(__clear_user_std)
23 WEAK(arm_clear_user)
24 UNWIND(.fnstart)
25 UNWIND(.save {r1, lr})
26 stmfd sp!, {r1, lr}
27 mov r2, #0
28 cmp r1, #4
29 blt 2f
30 ands ip, r0, #3
31 beq 1f
32 cmp ip, #2
33 strusr r2, r0, 1
34 strusr r2, r0, 1, le
35 strusr r2, r0, 1, lt
36 rsb ip, ip, #4
37 sub r1, r1, ip @ 7 6 5 4 3 2 1
38 1: subs r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7
39 strusr r2, r0, 4, pl, rept=2
40 bpl 1b
41 adds r1, r1, #4 @ 3 2 1 0 -1 -2 -3
42 strusr r2, r0, 4, pl
43 2: tst r1, #2 @ 1x 1x 0x 0x 1x 1x 0x
44 strusr r2, r0, 1, ne, rept=2
45 tst r1, #1 @ x1 x0 x1 x0 x1 x0 x1
46 it ne @ explicit IT needed for the label
47 USER( strnebt r2, [r0])
48 mov r0, #0
49 ldmfd sp!, {r1, pc}
50 UNWIND(.fnend)
51 ENDPROC(arm_clear_user)
52 ENDPROC(__clear_user_std)
53
54 .pushsection .text.fixup,"ax"
55 .align 0
56 9001: ldmfd sp!, {r0, pc}
57 .popsection
58
This page took 0.032661 seconds and 5 git commands to generate.