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d73e60b7 RK |
1 | /* |
2 | * linux/arch/arm/mm/copypage-v4wb.c | |
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 | #include <linux/init.h> | |
063b0a42 | 11 | #include <linux/highmem.h> |
d73e60b7 RK |
12 | |
13 | /* | |
063b0a42 | 14 | * ARMv4 optimised copy_user_highpage |
d73e60b7 RK |
15 | * |
16 | * We flush the destination cache lines just before we write the data into the | |
17 | * corresponding address. Since the Dcache is read-allocate, this removes the | |
18 | * Dcache aliasing issue. The writes will be forwarded to the write buffer, | |
19 | * and merged as appropriate. | |
20 | * | |
21 | * Note: We rely on all ARMv4 processors implementing the "invalidate D line" | |
22 | * instruction. If your processor does not supply this, you have to write your | |
063b0a42 | 23 | * own copy_user_highpage that does the right thing. |
d73e60b7 | 24 | */ |
446c92b2 | 25 | static void __naked |
063b0a42 | 26 | v4wb_copy_user_page(void *kto, const void *kfrom) |
d73e60b7 RK |
27 | { |
28 | asm("\ | |
29 | stmfd sp!, {r4, lr} @ 2\n\ | |
30 | mov r2, %0 @ 1\n\ | |
31 | ldmia r1!, {r3, r4, ip, lr} @ 4\n\ | |
32 | 1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\ | |
33 | stmia r0!, {r3, r4, ip, lr} @ 4\n\ | |
34 | ldmia r1!, {r3, r4, ip, lr} @ 4+1\n\ | |
35 | stmia r0!, {r3, r4, ip, lr} @ 4\n\ | |
36 | ldmia r1!, {r3, r4, ip, lr} @ 4\n\ | |
37 | mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line\n\ | |
38 | stmia r0!, {r3, r4, ip, lr} @ 4\n\ | |
39 | ldmia r1!, {r3, r4, ip, lr} @ 4\n\ | |
40 | subs r2, r2, #1 @ 1\n\ | |
41 | stmia r0!, {r3, r4, ip, lr} @ 4\n\ | |
42 | ldmneia r1!, {r3, r4, ip, lr} @ 4\n\ | |
43 | bne 1b @ 1\n\ | |
44 | mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB\n\ | |
45 | ldmfd sp!, {r4, pc} @ 3" | |
46 | : | |
47 | : "I" (PAGE_SIZE / 64)); | |
48 | } | |
49 | ||
063b0a42 RK |
50 | void v4wb_copy_user_highpage(struct page *to, struct page *from, |
51 | unsigned long vaddr) | |
52 | { | |
53 | void *kto, *kfrom; | |
54 | ||
55 | kto = kmap_atomic(to, KM_USER0); | |
56 | kfrom = kmap_atomic(from, KM_USER1); | |
57 | v4wb_copy_user_page(kto, kfrom); | |
58 | kunmap_atomic(kfrom, KM_USER1); | |
59 | kunmap_atomic(kto, KM_USER0); | |
60 | } | |
61 | ||
d73e60b7 RK |
62 | /* |
63 | * ARMv4 optimised clear_user_page | |
64 | * | |
65 | * Same story as above. | |
66 | */ | |
303c6443 | 67 | void v4wb_clear_user_highpage(struct page *page, unsigned long vaddr) |
d73e60b7 | 68 | { |
43ae286b NP |
69 | void *ptr, *kaddr = kmap_atomic(page, KM_USER0); |
70 | asm volatile("\ | |
71 | mov r1, %2 @ 1\n\ | |
d73e60b7 RK |
72 | mov r2, #0 @ 1\n\ |
73 | mov r3, #0 @ 1\n\ | |
74 | mov ip, #0 @ 1\n\ | |
75 | mov lr, #0 @ 1\n\ | |
303c6443 RK |
76 | 1: mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\ |
77 | stmia %0!, {r2, r3, ip, lr} @ 4\n\ | |
78 | stmia %0!, {r2, r3, ip, lr} @ 4\n\ | |
79 | mcr p15, 0, %0, c7, c6, 1 @ 1 invalidate D line\n\ | |
80 | stmia %0!, {r2, r3, ip, lr} @ 4\n\ | |
81 | stmia %0!, {r2, r3, ip, lr} @ 4\n\ | |
d73e60b7 RK |
82 | subs r1, r1, #1 @ 1\n\ |
83 | bne 1b @ 1\n\ | |
303c6443 | 84 | mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB" |
43ae286b NP |
85 | : "=r" (ptr) |
86 | : "0" (kaddr), "I" (PAGE_SIZE / 64) | |
303c6443 RK |
87 | : "r1", "r2", "r3", "ip", "lr"); |
88 | kunmap_atomic(kaddr, KM_USER0); | |
d73e60b7 RK |
89 | } |
90 | ||
91 | struct cpu_user_fns v4wb_user_fns __initdata = { | |
303c6443 | 92 | .cpu_clear_user_highpage = v4wb_clear_user_highpage, |
063b0a42 | 93 | .cpu_copy_user_highpage = v4wb_copy_user_highpage, |
d73e60b7 | 94 | }; |