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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* checksum.S: Sparc V9 optimized checksum code. |
3 | * | |
4 | * Copyright(C) 1995 Linus Torvalds | |
5 | * Copyright(C) 1995 Miguel de Icaza | |
6 | * Copyright(C) 1996, 2000 David S. Miller | |
7 | * Copyright(C) 1997 Jakub Jelinek | |
8 | * | |
9 | * derived from: | |
10 | * Linux/Alpha checksum c-code | |
11 | * Linux/ix86 inline checksum assembly | |
12 | * RFC1071 Computing the Internet Checksum (esp. Jacobsons m68k code) | |
13 | * David Mosberger-Tang for optimized reference c-code | |
14 | * BSD4.4 portable checksum routine | |
15 | */ | |
16 | ||
d3867f04 | 17 | #include <asm/export.h> |
1da177e4 LT |
18 | .text |
19 | ||
20 | csum_partial_fix_alignment: | |
21 | /* We checked for zero length already, so there must be | |
22 | * at least one byte. | |
23 | */ | |
24 | be,pt %icc, 1f | |
25 | nop | |
26 | ldub [%o0 + 0x00], %o4 | |
27 | add %o0, 1, %o0 | |
28 | sub %o1, 1, %o1 | |
29 | 1: andcc %o0, 0x2, %g0 | |
30 | be,pn %icc, csum_partial_post_align | |
31 | cmp %o1, 2 | |
32 | blu,pn %icc, csum_partial_end_cruft | |
33 | nop | |
34 | lduh [%o0 + 0x00], %o5 | |
35 | add %o0, 2, %o0 | |
36 | sub %o1, 2, %o1 | |
37 | ba,pt %xcc, csum_partial_post_align | |
38 | add %o5, %o4, %o4 | |
39 | ||
40 | .align 32 | |
41 | .globl csum_partial | |
f5a651f1 | 42 | .type csum_partial,#function |
d3867f04 | 43 | EXPORT_SYMBOL(csum_partial) |
1da177e4 LT |
44 | csum_partial: /* %o0=buff, %o1=len, %o2=sum */ |
45 | prefetch [%o0 + 0x000], #n_reads | |
46 | clr %o4 | |
47 | prefetch [%o0 + 0x040], #n_reads | |
48 | brz,pn %o1, csum_partial_finish | |
49 | andcc %o0, 0x3, %g0 | |
50 | ||
51 | /* We "remember" whether the lowest bit in the address | |
52 | * was set in %g7. Because if it is, we have to swap | |
53 | * upper and lower 8 bit fields of the sum we calculate. | |
54 | */ | |
55 | bne,pn %icc, csum_partial_fix_alignment | |
56 | andcc %o0, 0x1, %g7 | |
57 | ||
58 | csum_partial_post_align: | |
59 | prefetch [%o0 + 0x080], #n_reads | |
60 | andncc %o1, 0x3f, %o3 | |
61 | ||
62 | prefetch [%o0 + 0x0c0], #n_reads | |
63 | sub %o1, %o3, %o1 | |
64 | brz,pn %o3, 2f | |
65 | prefetch [%o0 + 0x100], #n_reads | |
66 | ||
67 | /* So that we don't need to use the non-pairing | |
68 | * add-with-carry instructions we accumulate 32-bit | |
69 | * values into a 64-bit register. At the end of the | |
70 | * loop we fold it down to 32-bits and so on. | |
71 | */ | |
72 | prefetch [%o0 + 0x140], #n_reads | |
73 | 1: lduw [%o0 + 0x00], %o5 | |
74 | lduw [%o0 + 0x04], %g1 | |
75 | lduw [%o0 + 0x08], %g2 | |
76 | add %o4, %o5, %o4 | |
77 | lduw [%o0 + 0x0c], %g3 | |
78 | add %o4, %g1, %o4 | |
79 | lduw [%o0 + 0x10], %o5 | |
80 | add %o4, %g2, %o4 | |
81 | lduw [%o0 + 0x14], %g1 | |
82 | add %o4, %g3, %o4 | |
83 | lduw [%o0 + 0x18], %g2 | |
84 | add %o4, %o5, %o4 | |
85 | lduw [%o0 + 0x1c], %g3 | |
86 | add %o4, %g1, %o4 | |
87 | lduw [%o0 + 0x20], %o5 | |
88 | add %o4, %g2, %o4 | |
89 | lduw [%o0 + 0x24], %g1 | |
90 | add %o4, %g3, %o4 | |
91 | lduw [%o0 + 0x28], %g2 | |
92 | add %o4, %o5, %o4 | |
93 | lduw [%o0 + 0x2c], %g3 | |
94 | add %o4, %g1, %o4 | |
95 | lduw [%o0 + 0x30], %o5 | |
96 | add %o4, %g2, %o4 | |
97 | lduw [%o0 + 0x34], %g1 | |
98 | add %o4, %g3, %o4 | |
99 | lduw [%o0 + 0x38], %g2 | |
100 | add %o4, %o5, %o4 | |
101 | lduw [%o0 + 0x3c], %g3 | |
102 | add %o4, %g1, %o4 | |
103 | prefetch [%o0 + 0x180], #n_reads | |
104 | add %o4, %g2, %o4 | |
105 | subcc %o3, 0x40, %o3 | |
106 | add %o0, 0x40, %o0 | |
107 | bne,pt %icc, 1b | |
108 | add %o4, %g3, %o4 | |
109 | ||
110 | 2: and %o1, 0x3c, %o3 | |
111 | brz,pn %o3, 2f | |
112 | sub %o1, %o3, %o1 | |
113 | 1: lduw [%o0 + 0x00], %o5 | |
114 | subcc %o3, 0x4, %o3 | |
115 | add %o0, 0x4, %o0 | |
116 | bne,pt %icc, 1b | |
117 | add %o4, %o5, %o4 | |
118 | ||
119 | 2: | |
120 | /* fold 64-->32 */ | |
121 | srlx %o4, 32, %o5 | |
122 | srl %o4, 0, %o4 | |
123 | add %o4, %o5, %o4 | |
124 | srlx %o4, 32, %o5 | |
125 | srl %o4, 0, %o4 | |
126 | add %o4, %o5, %o4 | |
127 | ||
128 | /* fold 32-->16 */ | |
129 | sethi %hi(0xffff0000), %g1 | |
130 | srl %o4, 16, %o5 | |
131 | andn %o4, %g1, %g2 | |
132 | add %o5, %g2, %o4 | |
133 | srl %o4, 16, %o5 | |
134 | andn %o4, %g1, %g2 | |
135 | add %o5, %g2, %o4 | |
136 | ||
137 | csum_partial_end_cruft: | |
138 | /* %o4 has the 16-bit sum we have calculated so-far. */ | |
139 | cmp %o1, 2 | |
140 | blu,pt %icc, 1f | |
141 | nop | |
142 | lduh [%o0 + 0x00], %o5 | |
143 | sub %o1, 2, %o1 | |
144 | add %o0, 2, %o0 | |
145 | add %o4, %o5, %o4 | |
146 | 1: brz,pt %o1, 1f | |
147 | nop | |
148 | ldub [%o0 + 0x00], %o5 | |
149 | sub %o1, 1, %o1 | |
150 | add %o0, 1, %o0 | |
151 | sllx %o5, 8, %o5 | |
152 | add %o4, %o5, %o4 | |
153 | 1: | |
154 | /* fold 32-->16 */ | |
155 | sethi %hi(0xffff0000), %g1 | |
156 | srl %o4, 16, %o5 | |
157 | andn %o4, %g1, %g2 | |
158 | add %o5, %g2, %o4 | |
159 | srl %o4, 16, %o5 | |
160 | andn %o4, %g1, %g2 | |
161 | add %o5, %g2, %o4 | |
162 | ||
163 | 1: brz,pt %g7, 1f | |
164 | nop | |
165 | ||
166 | /* We started with an odd byte, byte-swap the result. */ | |
167 | srl %o4, 8, %o5 | |
168 | and %o4, 0xff, %g1 | |
169 | sll %g1, 8, %g1 | |
170 | or %o5, %g1, %o4 | |
171 | ||
ae5de0ff DM |
172 | 1: addcc %o2, %o4, %o2 |
173 | addc %g0, %o2, %o2 | |
1da177e4 LT |
174 | |
175 | csum_partial_finish: | |
176 | retl | |
ae5de0ff | 177 | srl %o2, 0, %o0 |