xref: /openbmc/linux/arch/arm/mm/copypage-fa.c (revision 2a598d0b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/arch/arm/lib/copypage-fa.S
4  *
5  *  Copyright (C) 2005 Faraday Corp.
6  *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
7  *
8  * Based on copypage-v4wb.S:
9  *  Copyright (C) 1995-1999 Russell King
10  */
11 #include <linux/init.h>
12 #include <linux/highmem.h>
13 
14 /*
15  * Faraday optimised copy_user_page
16  */
17 static void fa_copy_user_page(void *kto, const void *kfrom)
18 {
19 	int tmp;
20 
21 	asm volatile ("\
22 1:	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
23 	stmia	%0, {r3, r4, ip, lr}		@ 4\n\
24 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
25 	add	%0, %0, #16			@ 1\n\
26 	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
27 	stmia	%0, {r3, r4, ip, lr}		@ 4\n\
28 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
29 	add	%0, %0, #16			@ 1\n\
30 	subs	%2, %2, #1			@ 1\n\
31 	bne	1b				@ 1\n\
32 	mcr	p15, 0, %2, c7, c10, 4		@ 1   drain WB"
33 	: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
34 	: "2" (PAGE_SIZE / 32)
35 	: "r3", "r4", "ip", "lr");
36 }
37 
38 void fa_copy_user_highpage(struct page *to, struct page *from,
39 	unsigned long vaddr, struct vm_area_struct *vma)
40 {
41 	void *kto, *kfrom;
42 
43 	kto = kmap_atomic(to);
44 	kfrom = kmap_atomic(from);
45 	fa_copy_user_page(kto, kfrom);
46 	kunmap_atomic(kfrom);
47 	kunmap_atomic(kto);
48 }
49 
50 /*
51  * Faraday optimised clear_user_page
52  *
53  * Same story as above.
54  */
55 void fa_clear_user_highpage(struct page *page, unsigned long vaddr)
56 {
57 	void *ptr, *kaddr = kmap_atomic(page);
58 	asm volatile("\
59 	mov	r1, %2				@ 1\n\
60 	mov	r2, #0				@ 1\n\
61 	mov	r3, #0				@ 1\n\
62 	mov	ip, #0				@ 1\n\
63 	mov	lr, #0				@ 1\n\
64 1:	stmia	%0, {r2, r3, ip, lr}		@ 4\n\
65 	mcr	p15, 0, %0, c7, c14, 1		@ 1   clean and invalidate D line\n\
66 	add	%0, %0, #16			@ 1\n\
67 	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 	subs	r1, r1, #1			@ 1\n\
71 	bne	1b				@ 1\n\
72 	mcr	p15, 0, r1, c7, c10, 4		@ 1   drain WB"
73 	: "=r" (ptr)
74 	: "0" (kaddr), "I" (PAGE_SIZE / 32)
75 	: "r1", "r2", "r3", "ip", "lr");
76 	kunmap_atomic(kaddr);
77 }
78 
79 struct cpu_user_fns fa_user_fns __initdata = {
80 	.cpu_clear_user_highpage = fa_clear_user_highpage,
81 	.cpu_copy_user_highpage	= fa_copy_user_highpage,
82 };
83