2 * linux/arch/arm/mm/copypage-v4wt.S
4 * Copyright (C) 1995-1999 Russell King
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.
10 * This is for CPUs with a writethrough cache and 'flush ID cache' is
11 * the only supported cache operation.
13 #include <linux/init.h>
14 #include <linux/highmem.h>
17 * ARMv4 optimised copy_user_highpage
19 * Since we have writethrough caches, we don't have to worry about
20 * dirty data in the cache. However, we do have to ensure that
21 * subsequent reads are up to date.
23 static void v4wt_copy_user_page(void *kto, const void *kfrom)
28 ldmia %1!, {r3, r4, ip, lr} @ 4\n\
29 1: stmia %0!, {r3, r4, ip, lr} @ 4\n\
30 ldmia %1!, {r3, r4, ip, lr} @ 4+1\n\
31 stmia %0!, {r3, r4, ip, lr} @ 4\n\
32 ldmia %1!, {r3, r4, ip, lr} @ 4\n\
33 stmia %0!, {r3, r4, ip, lr} @ 4\n\
34 ldmia %1!, {r3, r4, ip, lr} @ 4\n\
35 subs %2, %2, #1 @ 1\n\
36 stmia %0!, {r3, r4, ip, lr} @ 4\n\
37 ldmneia %1!, {r3, r4, ip, lr} @ 4\n\
39 mcr p15, 0, %2, c7, c7, 0 @ flush ID cache"
40 : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
41 : "2" (PAGE_SIZE / 64)
42 : "r3", "r4", "ip", "lr");
45 void v4wt_copy_user_highpage(struct page *to, struct page *from,
46 unsigned long vaddr, struct vm_area_struct *vma)
50 kto = kmap_atomic(to);
51 kfrom = kmap_atomic(from);
52 v4wt_copy_user_page(kto, kfrom);
58 * ARMv4 optimised clear_user_page
60 * Same story as above.
62 void v4wt_clear_user_highpage(struct page *page, unsigned long vaddr)
64 void *ptr, *kaddr = kmap_atomic(page);
71 1: stmia %0!, {r2, r3, ip, lr} @ 4\n\
72 stmia %0!, {r2, r3, ip, lr} @ 4\n\
73 stmia %0!, {r2, r3, ip, lr} @ 4\n\
74 stmia %0!, {r2, r3, ip, lr} @ 4\n\
75 subs r1, r1, #1 @ 1\n\
77 mcr p15, 0, r2, c7, c7, 0 @ flush ID cache"
79 : "0" (kaddr), "I" (PAGE_SIZE / 64)
80 : "r1", "r2", "r3", "ip", "lr");
84 struct cpu_user_fns v4wt_user_fns __initdata = {
85 .cpu_clear_user_highpage = v4wt_clear_user_highpage,
86 .cpu_copy_user_highpage = v4wt_copy_user_highpage,