1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * linux/arch/arm/mm/copypage-v4wb.c
4 *
5 * Copyright (C) 1995-1999 Russell King
6 */
7 #include <linux/init.h>
8 #include <linux/highmem.h>
9
10 /*
11 * ARMv4 optimised copy_user_highpage
12 *
13 * We flush the destination cache lines just b
14 * corresponding address. Since the Dcache is
15 * Dcache aliasing issue. The writes will be
16 * and merged as appropriate.
17 *
18 * Note: We rely on all ARMv4 processors imple
19 * instruction. If your processor does not su
20 * own copy_user_highpage that does the right
21 */
22 static void v4wb_copy_user_page(void *kto, con
23 {
24 int tmp;
25
26 asm volatile ("\
27 .syntax unified\n\
28 ldmia %1!, {r3, r4, ip, lr}
29 1: mcr p15, 0, %0, c7, c6, 1
30 stmia %0!, {r3, r4, ip, lr}
31 ldmia %1!, {r3, r4, ip, lr}
32 stmia %0!, {r3, r4, ip, lr}
33 ldmia %1!, {r3, r4, ip, lr}
34 mcr p15, 0, %0, c7, c6, 1
35 stmia %0!, {r3, r4, ip, lr}
36 ldmia %1!, {r3, r4, ip, lr}
37 subs %2, %2, #1
38 stmia %0!, {r3, r4, ip, lr}
39 ldmiane %1!, {r3, r4, ip, lr}
40 bne 1b
41 mcr p15, 0, %1, c7, c10, 4
42 : "+&r" (kto), "+&r" (kfrom), "=&r" (t
43 : "2" (PAGE_SIZE / 64)
44 : "r3", "r4", "ip", "lr");
45 }
46
47 void v4wb_copy_user_highpage(struct page *to,
48 unsigned long vaddr, struct vm_area_st
49 {
50 void *kto, *kfrom;
51
52 kto = kmap_atomic(to);
53 kfrom = kmap_atomic(from);
54 flush_cache_page(vma, vaddr, page_to_p
55 v4wb_copy_user_page(kto, kfrom);
56 kunmap_atomic(kfrom);
57 kunmap_atomic(kto);
58 }
59
60 /*
61 * ARMv4 optimised clear_user_page
62 *
63 * Same story as above.
64 */
65 void v4wb_clear_user_highpage(struct page *pag
66 {
67 void *ptr, *kaddr = kmap_atomic(page);
68 asm volatile("\
69 mov r1, %2
70 mov r2, #0
71 mov r3, #0
72 mov ip, #0
73 mov lr, #0
74 1: mcr p15, 0, %0, c7, c6, 1
75 stmia %0!, {r2, r3, ip, lr}
76 stmia %0!, {r2, r3, ip, lr}
77 mcr p15, 0, %0, c7, c6, 1
78 stmia %0!, {r2, r3, ip, lr}
79 stmia %0!, {r2, r3, ip, lr}
80 subs r1, r1, #1
81 bne 1b
82 mcr p15, 0, r1, c7, c10, 4
83 : "=r" (ptr)
84 : "" (kaddr), "I" (PAGE_SIZE / 64)
85 : "r1", "r2", "r3", "ip", "lr");
86 kunmap_atomic(kaddr);
87 }
88
89 struct cpu_user_fns v4wb_user_fns __initdata =
90 .cpu_clear_user_highpage = v4wb_clear_
91 .cpu_copy_user_highpage = v4wb_copy_us
92 };
93
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