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
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
|
/*
* linux/arch/arm/lib/csumpartialcopygeneric.S
*
* Copyright (C) 1995-2001 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/*
* unsigned int
* csum_partial_copy_xxx(const char *src, char *dst, int len, int sum, )
* r0 = src, r1 = dst, r2 = len, r3 = sum
* Returns : r0 = checksum
*
* Note that 'tst' and 'teq' preserve the carry flag.
*/
src .req r0
dst .req r1
len .req r2
sum .req r3
.Lzero: mov r0, sum
load_regs
/*
* Align an unaligned destination pointer. We know that
* we have >= 8 bytes here, so we don't need to check
* the length. Note that the source pointer hasn't been
* aligned yet.
*/
.Ldst_unaligned:
tst dst, #1
beq .Ldst_16bit
load1b ip
sub len, len, #1
adcs sum, sum, ip, put_byte_1 @ update checksum
strb ip, [dst], #1
tst dst, #2
moveq pc, lr @ dst is now 32bit aligned
.Ldst_16bit: load2b r8, ip
sub len, len, #2
adcs sum, sum, r8, put_byte_0
strb r8, [dst], #1
adcs sum, sum, ip, put_byte_1
strb ip, [dst], #1
mov pc, lr @ dst is now 32bit aligned
/*
* Handle 0 to 7 bytes, with any alignment of source and
* destination pointers. Note that when we get here, C = 0
*/
.Lless8: teq len, #0 @ check for zero count
beq .Lzero
/* we must have at least one byte. */
tst dst, #1 @ dst 16-bit aligned
beq .Lless8_aligned
/* Align dst */
load1b ip
sub len, len, #1
adcs sum, sum, ip, put_byte_1 @ update checksum
strb ip, [dst], #1
tst len, #6
beq .Lless8_byteonly
1: load2b r8, ip
sub len, len, #2
adcs sum, sum, r8, put_byte_0
strb r8, [dst], #1
adcs sum, sum, ip, put_byte_1
strb ip, [dst], #1
.Lless8_aligned:
tst len, #6
bne 1b
.Lless8_byteonly:
tst len, #1
beq .Ldone
load1b r8
adcs sum, sum, r8, put_byte_0 @ update checksum
strb r8, [dst], #1
b .Ldone
FN_ENTRY
save_regs
cmp len, #8 @ Ensure that we have at least
blo .Lless8 @ 8 bytes to copy.
adds sum, sum, #0 @ C = 0
tst dst, #3 @ Test destination alignment
blne .Ldst_unaligned @ align destination, return here
/*
* Ok, the dst pointer is now 32bit aligned, and we know
* that we must have more than 4 bytes to copy. Note
* that C contains the carry from the dst alignment above.
*/
tst src, #3 @ Test source alignment
bne .Lsrc_not_aligned
/* Routine for src & dst aligned */
bics ip, len, #15
beq 2f
1: load4l r4, r5, r6, r7
stmia dst!, {r4, r5, r6, r7}
adcs sum, sum, r4
adcs sum, sum, r5
adcs sum, sum, r6
adcs sum, sum, r7
sub ip, ip, #16
teq ip, #0
bne 1b
2: ands ip, len, #12
beq 4f
tst ip, #8
beq 3f
load2l r4, r5
stmia dst!, {r4, r5}
adcs sum, sum, r4
adcs sum, sum, r5
tst ip, #4
beq 4f
3: load1l r4
str r4, [dst], #4
adcs sum, sum, r4
4: ands len, len, #3
beq .Ldone
load1l r4
tst len, #2
mov r5, r4, get_byte_0
beq .Lexit
adcs sum, sum, r4, lspush #16
strb r5, [dst], #1
mov r5, r4, get_byte_1
strb r5, [dst], #1
mov r5, r4, get_byte_2
.Lexit: tst len, #1
strneb r5, [dst], #1
andne r5, r5, #255
adcnes sum, sum, r5, put_byte_0
/*
* If the dst pointer was not 16-bit aligned, we
* need to rotate the checksum here to get around
* the inefficient byte manipulations in the
* architecture independent code.
*/
.Ldone: adc r0, sum, #0
ldr sum, [sp, #0] @ dst
tst sum, #1
movne r0, r0, ror #8
load_regs
.Lsrc_not_aligned:
adc sum, sum, #0 @ include C from dst alignment
and ip, src, #3
bic src, src, #3
load1l r5
cmp ip, #2
beq .Lsrc2_aligned
bhi .Lsrc3_aligned
mov r4, r5, lspull #8 @ C = 0
bics ip, len, #15
beq 2f
1: load4l r5, r6, r7, r8
orr r4, r4, r5, lspush #24
mov r5, r5, lspull #8
orr r5, r5, r6, lspush #24
mov r6, r6, lspull #8
orr r6, r6, r7, lspush #24
mov r7, r7, lspull #8
orr r7, r7, r8, lspush #24
stmia dst!, {r4, r5, r6, r7}
adcs sum, sum, r4
adcs sum, sum, r5
adcs sum, sum, r6
adcs sum, sum, r7
mov r4, r8, lspull #8
sub ip, ip, #16
teq ip, #0
bne 1b
2: ands ip, len, #12
beq 4f
tst ip, #8
beq 3f
load2l r5, r6
orr r4, r4, r5, lspush #24
mov r5, r5, lspull #8
orr r5, r5, r6, lspush #24
stmia dst!, {r4, r5}
adcs sum, sum, r4
adcs sum, sum, r5
mov r4, r6, lspull #8
tst ip, #4
beq 4f
3: load1l r5
orr r4, r4, r5, lspush #24
str r4, [dst], #4
adcs sum, sum, r4
mov r4, r5, lspull #8
4: ands len, len, #3
beq .Ldone
mov r5, r4, get_byte_0
tst len, #2
beq .Lexit
adcs sum, sum, r4, lspush #16
strb r5, [dst], #1
mov r5, r4, get_byte_1
strb r5, [dst], #1
mov r5, r4, get_byte_2
b .Lexit
.Lsrc2_aligned: mov r4, r5, lspull #16
adds sum, sum, #0
bics ip, len, #15
beq 2f
1: load4l r5, r6, r7, r8
orr r4, r4, r5, lspush #16
mov r5, r5, lspull #16
orr r5, r5, r6, lspush #16
mov r6, r6, lspull #16
orr r6, r6, r7, lspush #16
mov r7, r7, lspull #16
orr r7, r7, r8, lspush #16
stmia dst!, {r4, r5, r6, r7}
adcs sum, sum, r4
adcs sum, sum, r5
adcs sum, sum, r6
adcs sum, sum, r7
mov r4, r8, lspull #16
sub ip, ip, #16
teq ip, #0
bne 1b
2: ands ip, len, #12
beq 4f
tst ip, #8
beq 3f
load2l r5, r6
orr r4, r4, r5, lspush #16
mov r5, r5, lspull #16
orr r5, r5, r6, lspush #16
stmia dst!, {r4, r5}
adcs sum, sum, r4
adcs sum, sum, r5
mov r4, r6, lspull #16
tst ip, #4
beq 4f
3: load1l r5
orr r4, r4, r5, lspush #16
str r4, [dst], #4
adcs sum, sum, r4
mov r4, r5, lspull #16
4: ands len, len, #3
beq .Ldone
mov r5, r4, get_byte_0
tst len, #2
beq .Lexit
adcs sum, sum, r4
strb r5, [dst], #1
mov r5, r4, get_byte_1
strb r5, [dst], #1
tst len, #1
beq .Ldone
load1b r5
b .Lexit
.Lsrc3_aligned: mov r4, r5, lspull #24
adds sum, sum, #0
bics ip, len, #15
beq 2f
1: load4l r5, r6, r7, r8
orr r4, r4, r5, lspush #8
mov r5, r5, lspull #24
orr r5, r5, r6, lspush #8
mov r6, r6, lspull #24
orr r6, r6, r7, lspush #8
mov r7, r7, lspull #24
orr r7, r7, r8, lspush #8
stmia dst!, {r4, r5, r6, r7}
adcs sum, sum, r4
adcs sum, sum, r5
adcs sum, sum, r6
adcs sum, sum, r7
mov r4, r8, lspull #24
sub ip, ip, #16
teq ip, #0
bne 1b
2: ands ip, len, #12
beq 4f
tst ip, #8
beq 3f
load2l r5, r6
orr r4, r4, r5, lspush #8
mov r5, r5, lspull #24
orr r5, r5, r6, lspush #8
stmia dst!, {r4, r5}
adcs sum, sum, r4
adcs sum, sum, r5
mov r4, r6, lspull #24
tst ip, #4
beq 4f
3: load1l r5
orr r4, r4, r5, lspush #8
str r4, [dst], #4
adcs sum, sum, r4
mov r4, r5, lspull #24
4: ands len, len, #3
beq .Ldone
mov r5, r4, get_byte_0
tst len, #2
beq .Lexit
strb r5, [dst], #1
adcs sum, sum, r4
load1l r4
mov r5, r4, get_byte_0
strb r5, [dst], #1
adcs sum, sum, r4, lspush #24
mov r5, r4, get_byte_1
b .Lexit
FN_EXIT
|
