xref: /openbmc/linux/arch/arm/mm/copypage-fa.c (revision 4f3db074)
1 /*
2  *  linux/arch/arm/lib/copypage-fa.S
3  *
4  *  Copyright (C) 2005 Faraday Corp.
5  *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
6  *
7  * Based on copypage-v4wb.S:
8  *  Copyright (C) 1995-1999 Russell King
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 #include <linux/init.h>
15 #include <linux/highmem.h>
16 
17 /*
18  * Faraday optimised copy_user_page
19  */
20 static void __naked
21 fa_copy_user_page(void *kto, const void *kfrom)
22 {
23 	asm("\
24 	stmfd	sp!, {r4, lr}			@ 2\n\
25 	mov	r2, %0				@ 1\n\
26 1:	ldmia	r1!, {r3, r4, ip, lr}		@ 4\n\
27 	stmia	r0, {r3, r4, ip, lr}		@ 4\n\
28 	mcr	p15, 0, r0, c7, c14, 1		@ 1   clean and invalidate D line\n\
29 	add	r0, r0, #16			@ 1\n\
30 	ldmia	r1!, {r3, r4, ip, lr}		@ 4\n\
31 	stmia	r0, {r3, r4, ip, lr}		@ 4\n\
32 	mcr	p15, 0, r0, c7, c14, 1		@ 1   clean and invalidate D line\n\
33 	add	r0, r0, #16			@ 1\n\
34 	subs	r2, r2, #1			@ 1\n\
35 	bne	1b				@ 1\n\
36 	mcr	p15, 0, r2, c7, c10, 4		@ 1   drain WB\n\
37 	ldmfd	sp!, {r4, pc}			@ 3"
38 	:
39 	: "I" (PAGE_SIZE / 32));
40 }
41 
42 void fa_copy_user_highpage(struct page *to, struct page *from,
43 	unsigned long vaddr, struct vm_area_struct *vma)
44 {
45 	void *kto, *kfrom;
46 
47 	kto = kmap_atomic(to);
48 	kfrom = kmap_atomic(from);
49 	fa_copy_user_page(kto, kfrom);
50 	kunmap_atomic(kfrom);
51 	kunmap_atomic(kto);
52 }
53 
54 /*
55  * Faraday optimised clear_user_page
56  *
57  * Same story as above.
58  */
59 void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
60 {
61 	void *ptr, *kaddr = kmap_atomic(page);
62 	asm volatile("\
63 	mov	r1, %2				@ 1\n\
64 	mov	r2, #0				@ 1\n\
65 	mov	r3, #0				@ 1\n\
66 	mov	ip, #0				@ 1\n\
67 	mov	lr, #0				@ 1\n\
68 1:	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
69 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
70 	add	%0, %0, #16			@ 1\n\
71 	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
72 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
73 	add	%0, %0, #16			@ 1\n\
74 	subs	r1, r1, #1			@ 1\n\
75 	bne	1b				@ 1\n\
76 	mcr	p15, 0, r1, c7, c10, 4		@ 1   drain WB"
77 	: "=r" (ptr)
78 	: "0" (kaddr), "I" (PAGE_SIZE / 32)
79 	: "r1", "r2", "r3", "ip", "lr");
80 	kunmap_atomic(kaddr);
81 }
82 
83 struct cpu_user_fns fa_user_fns __initdata = {
84 	.cpu_clear_user_highpage = fa_clear_user_highpage,
85 	.cpu_copy_user_highpage	= fa_copy_user_highpage,
86 };
87