1 /*
2  *  linux/arch/arm/mm/copypage-v3.c
3  *
4  *  Copyright (C) 1995-1999 Russell King
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 #include <linux/init.h>
11 #include <linux/highmem.h>
12 
13 /*
14  * ARMv3 optimised copy_user_highpage
15  *
16  * FIXME: do we need to handle cache stuff...
17  */
18 static void __naked
v3_copy_user_page(void * kto,const void * kfrom)19 v3_copy_user_page(void *kto, const void *kfrom)
20 {
21 	asm("\n\
22 	stmfd	sp!, {r4, lr}			@	2\n\
23 	mov	r2, %2				@	1\n\
24 	ldmia	%0!, {r3, r4, ip, lr}		@	4+1\n\
25 1:	stmia	%1!, {r3, r4, ip, lr}		@	4\n\
26 	ldmia	%0!, {r3, r4, ip, lr}		@	4+1\n\
27 	stmia	%1!, {r3, r4, ip, lr}		@	4\n\
28 	ldmia	%0!, {r3, r4, ip, lr}		@	4+1\n\
29 	stmia	%1!, {r3, r4, ip, lr}		@	4\n\
30 	ldmia	%0!, {r3, r4, ip, lr}		@	4\n\
31 	subs	r2, r2, #1			@	1\n\
32 	stmia	%1!, {r3, r4, ip, lr}		@	4\n\
33 	ldmneia	%0!, {r3, r4, ip, lr}		@	4\n\
34 	bne	1b				@	1\n\
35 	ldmfd	sp!, {r4, pc}			@	3"
36 	:
37 	: "r" (kfrom), "r" (kto), "I" (PAGE_SIZE / 64));
38 }
39 
v3_copy_user_highpage(struct page * to,struct page * from,unsigned long vaddr,struct vm_area_struct * vma)40 void v3_copy_user_highpage(struct page *to, struct page *from,
41 	unsigned long vaddr, struct vm_area_struct *vma)
42 {
43 	void *kto, *kfrom;
44 
45 	kto = kmap_atomic(to, KM_USER0);
46 	kfrom = kmap_atomic(from, KM_USER1);
47 	v3_copy_user_page(kto, kfrom);
48 	kunmap_atomic(kfrom, KM_USER1);
49 	kunmap_atomic(kto, KM_USER0);
50 }
51 
52 /*
53  * ARMv3 optimised clear_user_page
54  *
55  * FIXME: do we need to handle cache stuff...
56  */
v3_clear_user_highpage(struct page * page,unsigned long vaddr)57 void v3_clear_user_highpage(struct page *page, unsigned long vaddr)
58 {
59 	void *ptr, *kaddr = kmap_atomic(page, KM_USER0);
60 	asm volatile("\n\
61 	mov	r1, %2				@ 1\n\
62 	mov	r2, #0				@ 1\n\
63 	mov	r3, #0				@ 1\n\
64 	mov	ip, #0				@ 1\n\
65 	mov	lr, #0				@ 1\n\
66 1:	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
67 	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
68 	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
69 	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
70 	subs	r1, r1, #1			@ 1\n\
71 	bne	1b				@ 1"
72 	: "=r" (ptr)
73 	: "0" (kaddr), "I" (PAGE_SIZE / 64)
74 	: "r1", "r2", "r3", "ip", "lr");
75 	kunmap_atomic(kaddr, KM_USER0);
76 }
77 
78 struct cpu_user_fns v3_user_fns __initdata = {
79 	.cpu_clear_user_highpage = v3_clear_user_highpage,
80 	.cpu_copy_user_highpage	= v3_copy_user_highpage,
81 };
82