xref: /openbmc/linux/arch/arm/mm/copypage-fa.c (revision a2818ee4)
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 fa_copy_user_page(void *kto, const void *kfrom)
21 {
22 	int tmp;
23 
24 	asm volatile ("\
25 1:	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
26 	stmia	%0, {r3, r4, ip, lr}		@ 4\n\
27 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
28 	add	%0, %0, #16			@ 1\n\
29 	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
30 	stmia	%0, {r3, r4, ip, lr}		@ 4\n\
31 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
32 	add	%0, %0, #16			@ 1\n\
33 	subs	%2, %2, #1			@ 1\n\
34 	bne	1b				@ 1\n\
35 	mcr	p15, 0, %2, c7, c10, 4		@ 1   drain WB"
36 	: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
37 	: "2" (PAGE_SIZE / 32)
38 	: "r3", "r4", "ip", "lr");
39 }
40 
41 void fa_copy_user_highpage(struct page *to, struct page *from,
42 	unsigned long vaddr, struct vm_area_struct *vma)
43 {
44 	void *kto, *kfrom;
45 
46 	kto = kmap_atomic(to);
47 	kfrom = kmap_atomic(from);
48 	fa_copy_user_page(kto, kfrom);
49 	kunmap_atomic(kfrom);
50 	kunmap_atomic(kto);
51 }
52 
53 /*
54  * Faraday optimised clear_user_page
55  *
56  * Same story as above.
57  */
58 void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
59 {
60 	void *ptr, *kaddr = kmap_atomic(page);
61 	asm volatile("\
62 	mov	r1, %2				@ 1\n\
63 	mov	r2, #0				@ 1\n\
64 	mov	r3, #0				@ 1\n\
65 	mov	ip, #0				@ 1\n\
66 	mov	lr, #0				@ 1\n\
67 1:	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
68 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
69 	add	%0, %0, #16			@ 1\n\
70 	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
71 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
72 	add	%0, %0, #16			@ 1\n\
73 	subs	r1, r1, #1			@ 1\n\
74 	bne	1b				@ 1\n\
75 	mcr	p15, 0, r1, c7, c10, 4		@ 1   drain WB"
76 	: "=r" (ptr)
77 	: "0" (kaddr), "I" (PAGE_SIZE / 32)
78 	: "r1", "r2", "r3", "ip", "lr");
79 	kunmap_atomic(kaddr);
80 }
81 
82 struct cpu_user_fns fa_user_fns __initdata = {
83 	.cpu_clear_user_highpage = fa_clear_user_highpage,
84 	.cpu_copy_user_highpage	= fa_copy_user_highpage,
85 };
86