1 /*
2 * linux/arch/arm/mm/copypage-xsc3.S
3 *
4 * Copyright (C) 2004 Intel Corp.
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 * Adapted for 3rd gen XScale core, no more mini-dcache
11 * Author: Matt Gilbert (matthew.m.gilbert@intel.com)
12 */
13 #include <linux/init.h>
14 #include <linux/highmem.h>
15
16 /*
17 * General note:
18 * We don't really want write-allocate cache behaviour for these functions
19 * since that will just eat through 8K of the cache.
20 */
21
22 /*
23 * XSC3 optimised copy_user_highpage
24 *
25 * The source page may have some clean entries in the cache already, but we
26 * can safely ignore them - break_cow() will flush them out of the cache
27 * if we eventually end up using our copied page.
28 *
29 */
xsc3_mc_copy_user_page(void * kto,const void * kfrom)30 static void xsc3_mc_copy_user_page(void *kto, const void *kfrom)
31 {
32 int tmp;
33
34 asm volatile ("\
35 pld [%1, #0] \n\
36 pld [%1, #32] \n\
37 1: pld [%1, #64] \n\
38 pld [%1, #96] \n\
39 \n\
40 2: ldrd r2, [%1], #8 \n\
41 ldrd r4, [%1], #8 \n\
42 mcr p15, 0, %0, c7, c6, 1 @ invalidate\n\
43 strd r2, [%0], #8 \n\
44 ldrd r2, [%1], #8 \n\
45 strd r4, [%0], #8 \n\
46 ldrd r4, [%1], #8 \n\
47 strd r2, [%0], #8 \n\
48 strd r4, [%0], #8 \n\
49 ldrd r2, [%1], #8 \n\
50 ldrd r4, [%1], #8 \n\
51 mcr p15, 0, %0, c7, c6, 1 @ invalidate\n\
52 strd r2, [%0], #8 \n\
53 ldrd r2, [%1], #8 \n\
54 subs %2, %2, #1 \n\
55 strd r4, [%0], #8 \n\
56 ldrd r4, [%1], #8 \n\
57 strd r2, [%0], #8 \n\
58 strd r4, [%0], #8 \n\
59 bgt 1b \n\
60 beq 2b "
61 : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
62 : "2" (PAGE_SIZE / 64 - 1)
63 : "r2", "r3", "r4", "r5");
64 }
65
xsc3_mc_copy_user_highpage(struct page * to,struct page * from,unsigned long vaddr,struct vm_area_struct * vma)66 void xsc3_mc_copy_user_highpage(struct page *to, struct page *from,
67 unsigned long vaddr, struct vm_area_struct *vma)
68 {
69 void *kto, *kfrom;
70
71 kto = kmap_atomic(to);
72 kfrom = kmap_atomic(from);
73 flush_cache_page(vma, vaddr, page_to_pfn(from));
74 xsc3_mc_copy_user_page(kto, kfrom);
75 kunmap_atomic(kfrom);
76 kunmap_atomic(kto);
77 }
78
79 /*
80 * XScale optimised clear_user_page
81 */
xsc3_mc_clear_user_highpage(struct page * page,unsigned long vaddr)82 void xsc3_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
83 {
84 void *ptr, *kaddr = kmap_atomic(page);
85 asm volatile ("\
86 mov r1, %2 \n\
87 mov r2, #0 \n\
88 mov r3, #0 \n\
89 1: mcr p15, 0, %0, c7, c6, 1 @ invalidate line\n\
90 strd r2, [%0], #8 \n\
91 strd r2, [%0], #8 \n\
92 strd r2, [%0], #8 \n\
93 strd r2, [%0], #8 \n\
94 subs r1, r1, #1 \n\
95 bne 1b"
96 : "=r" (ptr)
97 : "0" (kaddr), "I" (PAGE_SIZE / 32)
98 : "r1", "r2", "r3");
99 kunmap_atomic(kaddr);
100 }
101
102 struct cpu_user_fns xsc3_mc_user_fns __initdata = {
103 .cpu_clear_user_highpage = xsc3_mc_clear_user_highpage,
104 .cpu_copy_user_highpage = xsc3_mc_copy_user_highpage,
105 };
106