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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/lib/memset.S
*
* Copyright (C) 1995-2000 Russell King
*
* ASM optimised string functions
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/unwind.h>
.text
.align 5
ENTRY(mmioset)
ENTRY(memset)
UNWIND( .fnstart )
and r1, r1, #255 @ cast to unsigned char
ands r3, r0, #3 @ 1 unaligned?
mov ip, r0 @ preserve r0 as return value
bne 6f @ 1
/*
* we know that the pointer in ip is aligned to a word boundary.
*/
1: orr r1, r1, r1, lsl #8
orr r1, r1, r1, lsl #16
mov r3, r1
7: cmp r2, #16
blt 4f
#if ! CALGN(1)+0
/*
* We need 2 extra registers for this loop - use r8 and the LR
*/
stmfd sp!, {r8, lr}
UNWIND( .fnend )
UNWIND( .fnstart )
UNWIND( .save {r8, lr} )
mov r8, r1
mov lr, r3
2: subs r2, r2, #64
stmiage ip!, {r1, r3, r8, lr} @ 64 bytes at a time.
stmiage ip!, {r1, r3, r8, lr}
stmiage ip!, {r1, r3, r8, lr}
stmiage ip!, {r1, r3, r8, lr}
bgt 2b
ldmfdeq sp!, {r8, pc} @ Now <64 bytes to go.
/*
* No need to correct the count; we're only testing bits from now on
*/
tst r2, #32
stmiane ip!, {r1, r3, r8, lr}
stmiane ip!, {r1, r3, r8, lr}
tst r2, #16
stmiane ip!, {r1, r3, r8, lr}
ldmfd sp!, {r8, lr}
UNWIND( .fnend )
#else
/*
* This version aligns the destination pointer in order to write
* whole cache lines at once.
*/
stmfd sp!, {r4-r8, lr}
UNWIND( .fnend )
UNWIND( .fnstart )
UNWIND( .save {r4-r8, lr} )
mov r4, r1
mov r5, r3
mov r6, r1
mov r7, r3
mov r8, r1
mov lr, r3
cmp r2, #96
tstgt ip, #31
ble 3f
and r8, ip, #31
rsb r8, r8, #32
sub r2, r2, r8
movs r8, r8, lsl #(32 - 4)
stmiacs ip!, {r4, r5, r6, r7}
stmiami ip!, {r4, r5}
tst r8, #(1 << 30)
mov r8, r1
strne r1, [ip], #4
3: subs r2, r2, #64
stmiage ip!, {r1, r3-r8, lr}
stmiage ip!, {r1, r3-r8, lr}
bgt 3b
ldmfdeq sp!, {r4-r8, pc}
tst r2, #32
stmiane ip!, {r1, r3-r8, lr}
tst r2, #16
stmiane ip!, {r4-r7}
ldmfd sp!, {r4-r8, lr}
UNWIND( .fnend )
#endif
UNWIND( .fnstart )
4: tst r2, #8
stmiane ip!, {r1, r3}
tst r2, #4
strne r1, [ip], #4
/*
* When we get here, we've got less than 4 bytes to set. We
* may have an unaligned pointer as well.
*/
5: tst r2, #2
strbne r1, [ip], #1
strbne r1, [ip], #1
tst r2, #1
strbne r1, [ip], #1
ret lr
6: subs r2, r2, #4 @ 1 do we have enough
blt 5b @ 1 bytes to align with?
cmp r3, #2 @ 1
strblt r1, [ip], #1 @ 1
strble r1, [ip], #1 @ 1
strb r1, [ip], #1 @ 1
add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
b 1b
UNWIND( .fnend )
ENDPROC(memset)
ENDPROC(mmioset)
ENTRY(__memset32)
UNWIND( .fnstart )
mov r3, r1 @ copy r1 to r3 and fall into memset64
UNWIND( .fnend )
ENDPROC(__memset32)
ENTRY(__memset64)
UNWIND( .fnstart )
mov ip, r0 @ preserve r0 as return value
b 7b @ jump into the middle of memset
UNWIND( .fnend )
ENDPROC(__memset64)
|
