tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * linux/arch/arm/lib/copypage-v4.S
3 *
4 * Copyright (C) 1995-1999 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 * ASM optimised string functions
11 *
12 * This is for CPUs with a writethrough cache and 'flush ID cache' is
13 * the only supported cache operation.
14 */
15#include <linux/linkage.h>
16#include <linux/init.h>
17#include <asm/asm-offsets.h>
18
19 .text
20 .align 5
21/*
22 * ARMv4 optimised copy_user_page
23 *
24 * Since we have writethrough caches, we don't have to worry about
25 * dirty data in the cache. However, we do have to ensure that
26 * subsequent reads are up to date.
27 */
28ENTRY(v4wt_copy_user_page)
29 stmfd sp!, {r4, lr} @ 2
30 mov r2, #PAGE_SZ/64 @ 1
31 ldmia r1!, {r3, r4, ip, lr} @ 4
321: stmia r0!, {r3, r4, ip, lr} @ 4
33 ldmia r1!, {r3, r4, ip, lr} @ 4+1
34 stmia r0!, {r3, r4, ip, lr} @ 4
35 ldmia r1!, {r3, r4, ip, lr} @ 4
36 stmia r0!, {r3, r4, ip, lr} @ 4
37 ldmia r1!, {r3, r4, ip, lr} @ 4
38 subs r2, r2, #1 @ 1
39 stmia r0!, {r3, r4, ip, lr} @ 4
40 ldmneia r1!, {r3, r4, ip, lr} @ 4
41 bne 1b @ 1
42 mcr p15, 0, r2, c7, c7, 0 @ flush ID cache
43 ldmfd sp!, {r4, pc} @ 3
44
45 .align 5
46/*
47 * ARMv4 optimised clear_user_page
48 *
49 * Same story as above.
50 */
51ENTRY(v4wt_clear_user_page)
52 str lr, [sp, #-4]!
53 mov r1, #PAGE_SZ/64 @ 1
54 mov r2, #0 @ 1
55 mov r3, #0 @ 1
56 mov ip, #0 @ 1
57 mov lr, #0 @ 1
581: stmia r0!, {r2, r3, ip, lr} @ 4
59 stmia r0!, {r2, r3, ip, lr} @ 4
60 stmia r0!, {r2, r3, ip, lr} @ 4
61 stmia r0!, {r2, r3, ip, lr} @ 4
62 subs r1, r1, #1 @ 1
63 bne 1b @ 1
64 mcr p15, 0, r2, c7, c7, 0 @ flush ID cache
65 ldr pc, [sp], #4
66
67 __INITDATA
68
69 .type v4wt_user_fns, #object
70ENTRY(v4wt_user_fns)
71 .long v4wt_clear_user_page
72 .long v4wt_copy_user_page
73 .size v4wt_user_fns, . - v4wt_user_fns