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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/export.h>
#include <asm/alternative-asm.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/asm-extable.h>
#include <asm/cpu.h>
#include <asm/regdef.h>
.irp to, 0, 1, 2, 3, 4, 5, 6, 7
.L_fixup_handle_\to\():
sub.d a0, a2, a0
addi.d a0, a0, (\to) * (-8)
jr ra
.endr
.irp to, 0, 2, 4
.L_fixup_handle_s\to\():
addi.d a0, a1, -\to
jr ra
.endr
SYM_FUNC_START(__clear_user)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __clear_user_generic", \
"b __clear_user_fast", CPU_FEATURE_UAL
SYM_FUNC_END(__clear_user)
EXPORT_SYMBOL(__clear_user)
/*
* unsigned long __clear_user_generic(void *addr, size_t size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user_generic)
beqz a1, 2f
1: st.b zero, a0, 0
addi.d a0, a0, 1
addi.d a1, a1, -1
bgtz a1, 1b
2: move a0, a1
jr ra
_asm_extable 1b, .L_fixup_handle_s0
SYM_FUNC_END(__clear_user_generic)
/*
* unsigned long __clear_user_fast(void *addr, unsigned long size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user_fast)
sltui t0, a1, 9
bnez t0, .Lsmall
add.d a2, a0, a1
0: st.d zero, a0, 0
/* align up address */
addi.d a0, a0, 8
bstrins.d a0, zero, 2, 0
addi.d a3, a2, -64
bgeu a0, a3, .Llt64
/* set 64 bytes at a time */
.Lloop64:
1: st.d zero, a0, 0
2: st.d zero, a0, 8
3: st.d zero, a0, 16
4: st.d zero, a0, 24
5: st.d zero, a0, 32
6: st.d zero, a0, 40
7: st.d zero, a0, 48
8: st.d zero, a0, 56
addi.d a0, a0, 64
bltu a0, a3, .Lloop64
/* set the remaining bytes */
.Llt64:
addi.d a3, a2, -32
bgeu a0, a3, .Llt32
9: st.d zero, a0, 0
10: st.d zero, a0, 8
11: st.d zero, a0, 16
12: st.d zero, a0, 24
addi.d a0, a0, 32
.Llt32:
addi.d a3, a2, -16
bgeu a0, a3, .Llt16
13: st.d zero, a0, 0
14: st.d zero, a0, 8
addi.d a0, a0, 16
.Llt16:
addi.d a3, a2, -8
bgeu a0, a3, .Llt8
15: st.d zero, a0, 0
addi.d a0, a0, 8
.Llt8:
16: st.d zero, a2, -8
/* return */
move a0, zero
jr ra
.align 4
.Lsmall:
pcaddi t0, 4
slli.d a2, a1, 4
add.d t0, t0, a2
jr t0
.align 4
move a0, zero
jr ra
.align 4
17: st.b zero, a0, 0
move a0, zero
jr ra
.align 4
18: st.h zero, a0, 0
move a0, zero
jr ra
.align 4
19: st.h zero, a0, 0
20: st.b zero, a0, 2
move a0, zero
jr ra
.align 4
21: st.w zero, a0, 0
move a0, zero
jr ra
.align 4
22: st.w zero, a0, 0
23: st.b zero, a0, 4
move a0, zero
jr ra
.align 4
24: st.w zero, a0, 0
25: st.h zero, a0, 4
move a0, zero
jr ra
.align 4
26: st.w zero, a0, 0
27: st.w zero, a0, 3
move a0, zero
jr ra
.align 4
28: st.d zero, a0, 0
move a0, zero
jr ra
/* fixup and ex_table */
_asm_extable 0b, .L_fixup_handle_0
_asm_extable 1b, .L_fixup_handle_0
_asm_extable 2b, .L_fixup_handle_1
_asm_extable 3b, .L_fixup_handle_2
_asm_extable 4b, .L_fixup_handle_3
_asm_extable 5b, .L_fixup_handle_4
_asm_extable 6b, .L_fixup_handle_5
_asm_extable 7b, .L_fixup_handle_6
_asm_extable 8b, .L_fixup_handle_7
_asm_extable 9b, .L_fixup_handle_0
_asm_extable 10b, .L_fixup_handle_1
_asm_extable 11b, .L_fixup_handle_2
_asm_extable 12b, .L_fixup_handle_3
_asm_extable 13b, .L_fixup_handle_0
_asm_extable 14b, .L_fixup_handle_1
_asm_extable 15b, .L_fixup_handle_0
_asm_extable 16b, .L_fixup_handle_0
_asm_extable 17b, .L_fixup_handle_s0
_asm_extable 18b, .L_fixup_handle_s0
_asm_extable 19b, .L_fixup_handle_s0
_asm_extable 20b, .L_fixup_handle_s2
_asm_extable 21b, .L_fixup_handle_s0
_asm_extable 22b, .L_fixup_handle_s0
_asm_extable 23b, .L_fixup_handle_s4
_asm_extable 24b, .L_fixup_handle_s0
_asm_extable 25b, .L_fixup_handle_s4
_asm_extable 26b, .L_fixup_handle_s0
_asm_extable 27b, .L_fixup_handle_s4
_asm_extable 28b, .L_fixup_handle_s0
SYM_FUNC_END(__clear_user_fast)
|
