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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * linux/arch/unicore32/lib/clear_user.S
4 *
5 * Code specific to PKUnity SoC and UniCore ISA
6 *
7 * Copyright (C) 2001-2010 GUAN Xue-tao
8 */
9#include <linux/linkage.h>
10#include <asm/assembler.h>
11
12 .text
13
14/* Prototype: int __clear_user(void *addr, size_t sz)
15 * Purpose : clear some user memory
16 * Params : addr - user memory address to clear
17 * : sz - number of bytes to clear
18 * Returns : number of bytes NOT cleared
19 */
20WEAK(__clear_user)
21 stm.w (lr), [sp-]
22 stm.w (r1), [sp-]
23 mov r2, #0
24 csub.a r1, #4
25 bsl 2f
26 and.a ip, r0, #3
27 beq 1f
28 csub.a ip, #2
29 strusr r2, r0, 1
30 strusr r2, r0, 1, el
31 strusr r2, r0, 1, sl
32 rsub ip, ip, #4
33 sub r1, r1, ip @ 7 6 5 4 3 2 1
341: sub.a r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7
35 strusr r2, r0, 4, ns, rept=2
36 bns 1b
37 add.a r1, r1, #4 @ 3 2 1 0 -1 -2 -3
38 strusr r2, r0, 4, ns
392: cand.a r1, #2 @ 1x 1x 0x 0x 1x 1x 0x
40 strusr r2, r0, 1, ne, rept=2
41 cand.a r1, #1 @ x1 x0 x1 x0 x1 x0 x1
42 beq 3f
43USER( stb.u r2, [r0])
443: mov r0, #0
45 ldm.w (r1), [sp]+
46 ldm.w (pc), [sp]+
47ENDPROC(__clear_user)
48
49 .pushsection .fixup,"ax"
50 .align 0
519001: ldm.w (r0), [sp]+
52 ldm.w (pc), [sp]+
53 .popsection
54