summaryrefslogtreecommitdiff
path: root/arch/x86/lib/copy_user_nocache_64.S
blob: b836a2bace15af28804c9b21cfa0bd21cd9b9fd3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
/*
 * Copyright 2008 Vitaly Mayatskikh <vmayatsk@redhat.com>
 * Copyright 2002 Andi Kleen, SuSE Labs.
 * Subject to the GNU Public License v2.
 *
 * Functions to copy from and to user space.
 */

#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/current.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/asm.h>
#include <asm/smap.h>

/*
 * copy_user_nocache - Uncached memory copy with exception handling
 * This will force destination/source out of cache for more performance.
 */
ENTRY(__copy_user_nocache)
	CFI_STARTPROC
	ASM_STAC
	cmpl $8,%edx
	jb 20f		/* less then 8 bytes, go to byte copy loop */
	ALIGN_DESTINATION
	movl %edx,%ecx
	andl $63,%edx
	shrl $6,%ecx
	jz 17f
1:	movq (%rsi),%r8
2:	movq 1*8(%rsi),%r9
3:	movq 2*8(%rsi),%r10
4:	movq 3*8(%rsi),%r11
5:	movnti %r8,(%rdi)
6:	movnti %r9,1*8(%rdi)
7:	movnti %r10,2*8(%rdi)
8:	movnti %r11,3*8(%rdi)
9:	movq 4*8(%rsi),%r8
10:	movq 5*8(%rsi),%r9
11:	movq 6*8(%rsi),%r10
12:	movq 7*8(%rsi),%r11
13:	movnti %r8,4*8(%rdi)
14:	movnti %r9,5*8(%rdi)
15:	movnti %r10,6*8(%rdi)
16:	movnti %r11,7*8(%rdi)
	leaq 64(%rsi),%rsi
	leaq 64(%rdi),%rdi
	decl %ecx
	jnz 1b
17:	movl %edx,%ecx
	andl $7,%edx
	shrl $3,%ecx
	jz 20f
18:	movq (%rsi),%r8
19:	movnti %r8,(%rdi)
	leaq 8(%rsi),%rsi
	leaq 8(%rdi),%rdi
	decl %ecx
	jnz 18b
20:	andl %edx,%edx
	jz 23f
	movl %edx,%ecx
21:	movb (%rsi),%al
22:	movb %al,(%rdi)
	incq %rsi
	incq %rdi
	decl %ecx
	jnz 21b
23:	xorl %eax,%eax
	ASM_CLAC
	sfence
	ret

	.section .fixup,"ax"
30:	shll $6,%ecx
	addl %ecx,%edx
	jmp 60f
40:	lea (%rdx,%rcx,8),%rdx
	jmp 60f
50:	movl %ecx,%edx
60:	sfence
	jmp copy_user_handle_tail
	.previous

	_ASM_EXTABLE(1b,30b)
	_ASM_EXTABLE(2b,30b)
	_ASM_EXTABLE(3b,30b)
	_ASM_EXTABLE(4b,30b)
	_ASM_EXTABLE(5b,30b)
	_ASM_EXTABLE(6b,30b)
	_ASM_EXTABLE(7b,30b)
	_ASM_EXTABLE(8b,30b)
	_ASM_EXTABLE(9b,30b)
	_ASM_EXTABLE(10b,30b)
	_ASM_EXTABLE(11b,30b)
	_ASM_EXTABLE(12b,30b)
	_ASM_EXTABLE(13b,30b)
	_ASM_EXTABLE(14b,30b)
	_ASM_EXTABLE(15b,30b)
	_ASM_EXTABLE(16b,30b)
	_ASM_EXTABLE(18b,40b)
	_ASM_EXTABLE(19b,40b)
	_ASM_EXTABLE(21b,50b)
	_ASM_EXTABLE(22b,50b)
	CFI_ENDPROC
ENDPROC(__copy_user_nocache)