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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
/*
* Copyright 2002, 2003 Andi Kleen, SuSE Labs.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details. No warranty for anything given at all.
*/
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/errno.h>
/*
* Checksum copy with exception handling.
* On exceptions src_err_ptr or dst_err_ptr is set to -EFAULT and the
* destination is zeroed.
*
* Input
* rdi source
* rsi destination
* edx len (32bit)
* ecx sum (32bit)
* r8 src_err_ptr (int)
* r9 dst_err_ptr (int)
*
* Output
* eax 64bit sum. undefined in case of exception.
*
* Wrappers need to take care of valid exception sum and zeroing.
* They also should align source or destination to 8 bytes.
*/
.macro source
10:
.section __ex_table, "a"
.align 8
.quad 10b, .Lbad_source
.previous
.endm
.macro dest
20:
.section __ex_table, "a"
.align 8
.quad 20b, .Lbad_dest
.previous
.endm
.macro ignore L=.Lignore
30:
.section __ex_table, "a"
.align 8
.quad 30b, \L
.previous
.endm
ENTRY(csum_partial_copy_generic)
CFI_STARTPROC
cmpl $3*64, %edx
jle .Lignore
.Lignore:
subq $7*8, %rsp
CFI_ADJUST_CFA_OFFSET 7*8
movq %rbx, 2*8(%rsp)
CFI_REL_OFFSET rbx, 2*8
movq %r12, 3*8(%rsp)
CFI_REL_OFFSET r12, 3*8
movq %r14, 4*8(%rsp)
CFI_REL_OFFSET r14, 4*8
movq %r13, 5*8(%rsp)
CFI_REL_OFFSET r13, 5*8
movq %rbp, 6*8(%rsp)
CFI_REL_OFFSET rbp, 6*8
movq %r8, (%rsp)
movq %r9, 1*8(%rsp)
movl %ecx, %eax
movl %edx, %ecx
xorl %r9d, %r9d
movq %rcx, %r12
shrq $6, %r12
jz .Lhandle_tail /* < 64 */
clc
/* main loop. clear in 64 byte blocks */
/* r9: zero, r8: temp2, rbx: temp1, rax: sum, rcx: saved length */
/* r11: temp3, rdx: temp4, r12 loopcnt */
/* r10: temp5, rbp: temp6, r14 temp7, r13 temp8 */
.p2align 4
.Lloop:
source
movq (%rdi), %rbx
source
movq 8(%rdi), %r8
source
movq 16(%rdi), %r11
source
movq 24(%rdi), %rdx
source
movq 32(%rdi), %r10
source
movq 40(%rdi), %rbp
source
movq 48(%rdi), %r14
source
movq 56(%rdi), %r13
ignore 2f
prefetcht0 5*64(%rdi)
2:
adcq %rbx, %rax
adcq %r8, %rax
adcq %r11, %rax
adcq %rdx, %rax
adcq %r10, %rax
adcq %rbp, %rax
adcq %r14, %rax
adcq %r13, %rax
decl %r12d
dest
movq %rbx, (%rsi)
dest
movq %r8, 8(%rsi)
dest
movq %r11, 16(%rsi)
dest
movq %rdx, 24(%rsi)
dest
movq %r10, 32(%rsi)
dest
movq %rbp, 40(%rsi)
dest
movq %r14, 48(%rsi)
dest
movq %r13, 56(%rsi)
3:
leaq 64(%rdi), %rdi
leaq 64(%rsi), %rsi
jnz .Lloop
adcq %r9, %rax
/* do last up to 56 bytes */
.Lhandle_tail:
/* ecx: count */
movl %ecx, %r10d
andl $63, %ecx
shrl $3, %ecx
jz .Lfold
clc
.p2align 4
.Lloop_8:
source
movq (%rdi), %rbx
adcq %rbx, %rax
decl %ecx
dest
movq %rbx, (%rsi)
leaq 8(%rsi), %rsi /* preserve carry */
leaq 8(%rdi), %rdi
jnz .Lloop_8
adcq %r9, %rax /* add in carry */
.Lfold:
/* reduce checksum to 32bits */
movl %eax, %ebx
shrq $32, %rax
addl %ebx, %eax
adcl %r9d, %eax
/* do last up to 6 bytes */
.Lhandle_7:
movl %r10d, %ecx
andl $7, %ecx
shrl $1, %ecx
jz .Lhandle_1
movl $2, %edx
xorl %ebx, %ebx
clc
.p2align 4
.Lloop_1:
source
movw (%rdi), %bx
adcl %ebx, %eax
decl %ecx
dest
movw %bx, (%rsi)
leaq 2(%rdi), %rdi
leaq 2(%rsi), %rsi
jnz .Lloop_1
adcl %r9d, %eax /* add in carry */
/* handle last odd byte */
.Lhandle_1:
testl $1, %r10d
jz .Lende
xorl %ebx, %ebx
source
movb (%rdi), %bl
dest
movb %bl, (%rsi)
addl %ebx, %eax
adcl %r9d, %eax /* carry */
CFI_REMEMBER_STATE
.Lende:
movq 2*8(%rsp), %rbx
CFI_RESTORE rbx
movq 3*8(%rsp), %r12
CFI_RESTORE r12
movq 4*8(%rsp), %r14
CFI_RESTORE r14
movq 5*8(%rsp), %r13
CFI_RESTORE r13
movq 6*8(%rsp), %rbp
CFI_RESTORE rbp
addq $7*8, %rsp
CFI_ADJUST_CFA_OFFSET -7*8
ret
CFI_RESTORE_STATE
/* Exception handlers. Very simple, zeroing is done in the wrappers */
.Lbad_source:
movq (%rsp), %rax
testq %rax, %rax
jz .Lende
movl $-EFAULT, (%rax)
jmp .Lende
.Lbad_dest:
movq 8(%rsp), %rax
testq %rax, %rax
jz .Lende
movl $-EFAULT, (%rax)
jmp .Lende
CFI_ENDPROC
ENDPROC(csum_partial_copy_generic)
|
