1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* checksum.S: Sparc V9 optimized checksum cod
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 Checksu
13 * David Mosberger-Tang for optimized ref
14 * BSD4.4 portable checksum routine
15 */
16
17 #include <linux/export.h>
18 .text
19
20 csum_partial_fix_alignment:
21 /* We checked for zero length already,
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_pos
31 cmp %o1, 2
32 blu,pn %icc, csum_partial_end
33 nop
34 lduh [%o0 + 0x00], %o5
35 add %o0, 2, %o0
36 sub %o1, 2, %o1
37 ba,pt %xcc, csum_partial_pos
38 add %o5, %o4, %o4
39
40 .align 32
41 .globl csum_partial
42 .type csum_partial,#function
43 EXPORT_SYMBOL(csum_partial)
44 csum_partial: /* %o0=buff, %o1=len,
45 prefetch [%o0 + 0x000], #n_read
46 clr %o4
47 prefetch [%o0 + 0x040], #n_read
48 brz,pn %o1, csum_partial_fini
49 andcc %o0, 0x3, %g0
50
51 /* We "remember" whether the lowest bi
52 * was set in %g7. Because if it is,
53 * upper and lower 8 bit fields of the
54 */
55 bne,pn %icc, csum_partial_fix
56 andcc %o0, 0x1, %g7
57
58 csum_partial_post_align:
59 prefetch [%o0 + 0x080], #n_read
60 andncc %o1, 0x3f, %o3
61
62 prefetch [%o0 + 0x0c0], #n_read
63 sub %o1, %o3, %o1
64 brz,pn %o3, 2f
65 prefetch [%o0 + 0x100], #n_read
66
67 /* So that we don't need to use the no
68 * add-with-carry instructions we accu
69 * values into a 64-bit register. At
70 * loop we fold it down to 32-bits and
71 */
72 prefetch [%o0 + 0x140], #n_read
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_read
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 calc
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-s
167 srl %o4, 8, %o5
168 and %o4, 0xff, %g1
169 sll %g1, 8, %g1
170 or %o5, %g1, %o4
171
172 1: addcc %o2, %o4, %o2
173 addc %g0, %o2, %o2
174
175 csum_partial_finish:
176 retl
177 srl %o2, 0, %o0
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