Commit | Line | Data |
---|---|---|
14cf11af PM |
1 | /* |
2 | * This file contains assembly-language implementations | |
3 | * of IP-style 1's complement checksum routines. | |
4 | * | |
5 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au). | |
13 | */ | |
14 | ||
15 | #include <linux/sys.h> | |
16 | #include <asm/processor.h> | |
17 | #include <asm/errno.h> | |
18 | #include <asm/ppc_asm.h> | |
19 | ||
20 | .text | |
21 | ||
22 | /* | |
23 | * ip_fast_csum(buf, len) -- Optimized for IP header | |
24 | * len is in words and is always >= 5. | |
25 | */ | |
26 | _GLOBAL(ip_fast_csum) | |
27 | lwz r0,0(r3) | |
28 | lwzu r5,4(r3) | |
29 | addic. r4,r4,-2 | |
30 | addc r0,r0,r5 | |
31 | mtctr r4 | |
32 | blelr- | |
33 | 1: lwzu r4,4(r3) | |
34 | adde r0,r0,r4 | |
35 | bdnz 1b | |
36 | addze r0,r0 /* add in final carry */ | |
37 | rlwinm r3,r0,16,0,31 /* fold two halves together */ | |
38 | add r3,r0,r3 | |
39 | not r3,r3 | |
40 | srwi r3,r3,16 | |
41 | blr | |
42 | ||
43 | /* | |
44 | * Compute checksum of TCP or UDP pseudo-header: | |
45 | * csum_tcpudp_magic(saddr, daddr, len, proto, sum) | |
46 | */ | |
47 | _GLOBAL(csum_tcpudp_magic) | |
48 | rlwimi r5,r6,16,0,15 /* put proto in upper half of len */ | |
49 | addc r0,r3,r4 /* add 4 32-bit words together */ | |
50 | adde r0,r0,r5 | |
51 | adde r0,r0,r7 | |
52 | addze r0,r0 /* add in final carry */ | |
53 | rlwinm r3,r0,16,0,31 /* fold two halves together */ | |
54 | add r3,r0,r3 | |
55 | not r3,r3 | |
56 | srwi r3,r3,16 | |
57 | blr | |
58 | ||
59 | /* | |
60 | * computes the checksum of a memory block at buff, length len, | |
61 | * and adds in "sum" (32-bit) | |
62 | * | |
63 | * csum_partial(buff, len, sum) | |
64 | */ | |
65 | _GLOBAL(csum_partial) | |
66 | addic r0,r5,0 | |
67 | subi r3,r3,4 | |
68 | srwi. r6,r4,2 | |
69 | beq 3f /* if we're doing < 4 bytes */ | |
70 | andi. r5,r3,2 /* Align buffer to longword boundary */ | |
71 | beq+ 1f | |
72 | lhz r5,4(r3) /* do 2 bytes to get aligned */ | |
73 | addi r3,r3,2 | |
74 | subi r4,r4,2 | |
75 | addc r0,r0,r5 | |
76 | srwi. r6,r4,2 /* # words to do */ | |
77 | beq 3f | |
78 | 1: mtctr r6 | |
79 | 2: lwzu r5,4(r3) /* the bdnz has zero overhead, so it should */ | |
80 | adde r0,r0,r5 /* be unnecessary to unroll this loop */ | |
81 | bdnz 2b | |
82 | andi. r4,r4,3 | |
83 | 3: cmpwi 0,r4,2 | |
84 | blt+ 4f | |
85 | lhz r5,4(r3) | |
86 | addi r3,r3,2 | |
87 | subi r4,r4,2 | |
88 | adde r0,r0,r5 | |
89 | 4: cmpwi 0,r4,1 | |
90 | bne+ 5f | |
91 | lbz r5,4(r3) | |
92 | slwi r5,r5,8 /* Upper byte of word */ | |
93 | adde r0,r0,r5 | |
94 | 5: addze r3,r0 /* add in final carry */ | |
95 | blr | |
96 | ||
97 | /* | |
98 | * Computes the checksum of a memory block at src, length len, | |
99 | * and adds in "sum" (32-bit), while copying the block to dst. | |
100 | * If an access exception occurs on src or dst, it stores -EFAULT | |
101 | * to *src_err or *dst_err respectively, and (for an error on | |
102 | * src) zeroes the rest of dst. | |
103 | * | |
104 | * csum_partial_copy_generic(src, dst, len, sum, src_err, dst_err) | |
105 | */ | |
106 | _GLOBAL(csum_partial_copy_generic) | |
107 | addic r0,r6,0 | |
108 | subi r3,r3,4 | |
109 | subi r4,r4,4 | |
110 | srwi. r6,r5,2 | |
111 | beq 3f /* if we're doing < 4 bytes */ | |
112 | andi. r9,r4,2 /* Align dst to longword boundary */ | |
113 | beq+ 1f | |
114 | 81: lhz r6,4(r3) /* do 2 bytes to get aligned */ | |
115 | addi r3,r3,2 | |
116 | subi r5,r5,2 | |
117 | 91: sth r6,4(r4) | |
118 | addi r4,r4,2 | |
119 | addc r0,r0,r6 | |
120 | srwi. r6,r5,2 /* # words to do */ | |
121 | beq 3f | |
122 | 1: srwi. r6,r5,4 /* # groups of 4 words to do */ | |
123 | beq 10f | |
124 | mtctr r6 | |
125 | 71: lwz r6,4(r3) | |
126 | 72: lwz r9,8(r3) | |
127 | 73: lwz r10,12(r3) | |
128 | 74: lwzu r11,16(r3) | |
129 | adde r0,r0,r6 | |
130 | 75: stw r6,4(r4) | |
131 | adde r0,r0,r9 | |
132 | 76: stw r9,8(r4) | |
133 | adde r0,r0,r10 | |
134 | 77: stw r10,12(r4) | |
135 | adde r0,r0,r11 | |
136 | 78: stwu r11,16(r4) | |
137 | bdnz 71b | |
138 | 10: rlwinm. r6,r5,30,30,31 /* # words left to do */ | |
139 | beq 13f | |
140 | mtctr r6 | |
141 | 82: lwzu r9,4(r3) | |
142 | 92: stwu r9,4(r4) | |
143 | adde r0,r0,r9 | |
144 | bdnz 82b | |
145 | 13: andi. r5,r5,3 | |
146 | 3: cmpwi 0,r5,2 | |
147 | blt+ 4f | |
148 | 83: lhz r6,4(r3) | |
149 | addi r3,r3,2 | |
150 | subi r5,r5,2 | |
151 | 93: sth r6,4(r4) | |
152 | addi r4,r4,2 | |
153 | adde r0,r0,r6 | |
154 | 4: cmpwi 0,r5,1 | |
155 | bne+ 5f | |
156 | 84: lbz r6,4(r3) | |
157 | 94: stb r6,4(r4) | |
158 | slwi r6,r6,8 /* Upper byte of word */ | |
159 | adde r0,r0,r6 | |
160 | 5: addze r3,r0 /* add in final carry */ | |
161 | blr | |
162 | ||
163 | /* These shouldn't go in the fixup section, since that would | |
164 | cause the ex_table addresses to get out of order. */ | |
165 | ||
166 | src_error_4: | |
167 | mfctr r6 /* update # bytes remaining from ctr */ | |
168 | rlwimi r5,r6,4,0,27 | |
169 | b 79f | |
170 | src_error_1: | |
171 | li r6,0 | |
172 | subi r5,r5,2 | |
173 | 95: sth r6,4(r4) | |
174 | addi r4,r4,2 | |
175 | 79: srwi. r6,r5,2 | |
176 | beq 3f | |
177 | mtctr r6 | |
178 | src_error_2: | |
179 | li r6,0 | |
180 | 96: stwu r6,4(r4) | |
181 | bdnz 96b | |
182 | 3: andi. r5,r5,3 | |
183 | beq src_error | |
184 | src_error_3: | |
185 | li r6,0 | |
186 | mtctr r5 | |
187 | addi r4,r4,3 | |
188 | 97: stbu r6,1(r4) | |
189 | bdnz 97b | |
190 | src_error: | |
191 | cmpwi 0,r7,0 | |
192 | beq 1f | |
193 | li r6,-EFAULT | |
194 | stw r6,0(r7) | |
195 | 1: addze r3,r0 | |
196 | blr | |
197 | ||
198 | dst_error: | |
199 | cmpwi 0,r8,0 | |
200 | beq 1f | |
201 | li r6,-EFAULT | |
202 | stw r6,0(r8) | |
203 | 1: addze r3,r0 | |
204 | blr | |
205 | ||
206 | .section __ex_table,"a" | |
207 | .long 81b,src_error_1 | |
208 | .long 91b,dst_error | |
209 | .long 71b,src_error_4 | |
210 | .long 72b,src_error_4 | |
211 | .long 73b,src_error_4 | |
212 | .long 74b,src_error_4 | |
213 | .long 75b,dst_error | |
214 | .long 76b,dst_error | |
215 | .long 77b,dst_error | |
216 | .long 78b,dst_error | |
217 | .long 82b,src_error_2 | |
218 | .long 92b,dst_error | |
219 | .long 83b,src_error_3 | |
220 | .long 93b,dst_error | |
221 | .long 84b,src_error_3 | |
222 | .long 94b,dst_error | |
223 | .long 95b,dst_error | |
224 | .long 96b,dst_error | |
225 | .long 97b,dst_error |