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
|
/*
* This module contains the PowerPC interrupt fielders
* set of code at specific locations, based on function
*/
#include <linux/sys.h>
#include "../kernel/ppc_asm.tmpl"
_TEXT()
/*
* Compute IP checksums
* _ip_fast_csum(buf, len) -- Optimized for IP header
* _ip_compute_csum(buf, len)
*/
_GLOBAL(_ip_fast_csum)
li r0,0
addic r0,r0,0 /* Clear initial carry */
lwz r4,0(r3)
lwz r5,4(r3)
adde r0,r0,r4
lwz r4,8(r3)
adde r0,r0,r5
lwz r5,12(r3)
adde r0,r0,r4
lwz r4,16(r3)
adde r0,r0,r5
adde r0,r0,r4
mr r3,r0
andi. r3,r3,0xFFFF
srwi r0,r0,16
adde r3,r3,r0
andis. r0,r3,1
beq 10f
addi r3,r3,1
10: not r3,r3
andi. r3,r3,0xFFFF
blr
_GLOBAL(_ip_compute_csum)
li r0,0
addic r0,r0,0
finish_ip_csum:
subi r3,r3,4
andi. r5,r3,2 /* Align buffer to longword boundary */
beq 10f
lhz r5,4(r3)
adde r0,r0,r5
addi r3,r3,2
subi r4,r4,2
10: cmpi 0,r4,16 /* unrolled loop - 16 bytes at a time */
blt 20f
lwz r5,4(r3)
lwz r6,8(r3)
adde r0,r0,r5
lwz r5,12(r3)
adde r0,r0,r6
lwzu r6,16(r3)
adde r0,r0,r5
adde r0,r0,r6
subi r4,r4,16
b 10b
20: cmpi 0,r4,4
blt 30f
lwzu r5,4(r3)
adde r0,r0,r5
subi r4,r4,4
b 20b
30: cmpi 0,r4,2
blt 40f
lhz r5,4(r3)
addi r3,r3,2
adde r0,r0,r5
subi r4,r4,2
40: cmpi 0,r4,1
bne 50f
lbz r5,4(r3)
slwi r5,r5,8 /* Upper byte of word */
adde r0,r0,r5
50: mr r3,r0
andi. r3,r3,0xFFFF
srwi r0,r0,16
adde r3,r3,r0
andis. r0,r3,1
beq 60f
addi r3,r3,1
60: not r3,r3
andi. r3,r3,0xFFFF
blr
_GLOBAL(_udp_check)
addc r0,r5,r6 /* Add in header fields */
adde r0,r0,r7
b finish_ip_csum
_GLOBAL(_tcp_check)
addc r0,r5,r6 /* Add in header fields */
adde r0,r0,r7
b finish_ip_csum
_GLOBAL(_csum_partial)
li r0,0
addc r0,r5,r0
b finish_ip_csum
/*
* Compute 16 bit sum:
* _csum_tcpudp_magic(int saddr, int daddr, int sum, int proto)
*/
_GLOBAL(_csum_tcpudp_magic)
addc r0,r3,r4
adde r0,r0,r5
adde r0,r0,r6
mr r3,r0
andi. r3,r3,0xFFFF
srwi r0,r0,16
adde r3,r3,r0
andis. r0,r3,1 /* Carry out of 16 bits? */
beq 10f
addi r3,r3,1
10: not r3,r3
andi. r3,r3,0xFFFF
blr
|
