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
|
/*
* This file contains assembly-language implementations
* of IP-style 1's complement checksum routines.
*
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au).
*/
#include <linux/sys.h>
#include <asm/processor.h>
#include <asm/errno.h>
#include <asm/ppc_asm.h>
.text
/*
* ip_fast_csum(buf, len) -- Optimized for IP header
* len is in words and is always >= 5.
*/
_GLOBAL(ip_fast_csum)
lwz r0,0(r3)
lwzu r5,4(r3)
addic. r4,r4,-2
addc r0,r0,r5
mtctr r4
blelr-
1: lwzu r4,4(r3)
adde r0,r0,r4
bdnz 1b
addze r0,r0 /* add in final carry */
rlwinm r3,r0,16,0,31 /* fold two halves together */
add r3,r0,r3
not r3,r3
srwi r3,r3,16
blr
/*
* computes the checksum of a memory block at buff, length len,
* and adds in "sum" (32-bit)
*
* csum_partial(buff, len, sum)
*/
_GLOBAL(csum_partial)
addic r0,r5,0
subi r3,r3,4
srwi. r6,r4,2
beq 3f /* if we're doing < 4 bytes */
andi. r5,r3,2 /* Align buffer to longword boundary */
beq+ 1f
lhz r5,4(r3) /* do 2 bytes to get aligned */
addi r3,r3,2
subi r4,r4,2
addc r0,r0,r5
srwi. r6,r4,2 /* # words to do */
beq 3f
1: mtctr r6
2: lwzu r5,4(r3) /* the bdnz has zero overhead, so it should */
adde r0,r0,r5 /* be unnecessary to unroll this loop */
bdnz 2b
andi. r4,r4,3
3: cmpwi 0,r4,2
blt+ 4f
lhz r5,4(r3)
addi r3,r3,2
subi r4,r4,2
adde r0,r0,r5
4: cmpwi 0,r4,1
bne+ 5f
lbz r5,4(r3)
slwi r5,r5,8 /* Upper byte of word */
adde r0,r0,r5
5: addze r3,r0 /* add in final carry */
blr
/*
* Computes the checksum of a memory block at src, length len,
* and adds in "sum" (32-bit), while copying the block to dst.
* If an access exception occurs on src or dst, it stores -EFAULT
* to *src_err or *dst_err respectively, and (for an error on
* src) zeroes the rest of dst.
*
* csum_partial_copy_generic(src, dst, len, sum, src_err, dst_err)
*/
_GLOBAL(csum_partial_copy_generic)
addic r0,r6,0
subi r3,r3,4
subi r4,r4,4
srwi. r6,r5,2
beq 3f /* if we're doing < 4 bytes */
andi. r9,r4,2 /* Align dst to longword boundary */
beq+ 1f
81: lhz r6,4(r3) /* do 2 bytes to get aligned */
addi r3,r3,2
subi r5,r5,2
91: sth r6,4(r4)
addi r4,r4,2
addc r0,r0,r6
srwi. r6,r5,2 /* # words to do */
beq 3f
1: srwi. r6,r5,4 /* # groups of 4 words to do */
beq 10f
mtctr r6
71: lwz r6,4(r3)
72: lwz r9,8(r3)
73: lwz r10,12(r3)
74: lwzu r11,16(r3)
adde r0,r0,r6
75: stw r6,4(r4)
adde r0,r0,r9
76: stw r9,8(r4)
adde r0,r0,r10
77: stw r10,12(r4)
adde r0,r0,r11
78: stwu r11,16(r4)
bdnz 71b
10: rlwinm. r6,r5,30,30,31 /* # words left to do */
beq 13f
mtctr r6
82: lwzu r9,4(r3)
92: stwu r9,4(r4)
adde r0,r0,r9
bdnz 82b
13: andi. r5,r5,3
3: cmpwi 0,r5,2
blt+ 4f
83: lhz r6,4(r3)
addi r3,r3,2
subi r5,r5,2
93: sth r6,4(r4)
addi r4,r4,2
adde r0,r0,r6
4: cmpwi 0,r5,1
bne+ 5f
84: lbz r6,4(r3)
94: stb r6,4(r4)
slwi r6,r6,8 /* Upper byte of word */
adde r0,r0,r6
5: addze r3,r0 /* add in final carry */
blr
/* These shouldn't go in the fixup section, since that would
cause the ex_table addresses to get out of order. */
src_error_4:
mfctr r6 /* update # bytes remaining from ctr */
rlwimi r5,r6,4,0,27
b 79f
src_error_1:
li r6,0
subi r5,r5,2
95: sth r6,4(r4)
addi r4,r4,2
79: srwi. r6,r5,2
beq 3f
mtctr r6
src_error_2:
li r6,0
96: stwu r6,4(r4)
bdnz 96b
3: andi. r5,r5,3
beq src_error
src_error_3:
li r6,0
mtctr r5
addi r4,r4,3
97: stbu r6,1(r4)
bdnz 97b
src_error:
cmpwi 0,r7,0
beq 1f
li r6,-EFAULT
stw r6,0(r7)
1: addze r3,r0
blr
dst_error:
cmpwi 0,r8,0
beq 1f
li r6,-EFAULT
stw r6,0(r8)
1: addze r3,r0
blr
.section __ex_table,"a"
.long 81b,src_error_1
.long 91b,dst_error
.long 71b,src_error_4
.long 72b,src_error_4
.long 73b,src_error_4
.long 74b,src_error_4
.long 75b,dst_error
.long 76b,dst_error
.long 77b,dst_error
.long 78b,dst_error
.long 82b,src_error_2
.long 92b,dst_error
.long 83b,src_error_3
.long 93b,dst_error
.long 84b,src_error_3
.long 94b,dst_error
.long 95b,dst_error
.long 96b,dst_error
.long 97b,dst_error
|
