Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
88278ca2 | 2 | /* |
1da177e4 LT |
3 | * memscan.S: Optimized memscan for the Sparc. |
4 | * | |
5 | * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) | |
6 | */ | |
7 | ||
4cdb71b6 | 8 | #include <linux/export.h> |
d3867f04 | 9 | |
1da177e4 LT |
10 | /* In essence, this is just a fancy strlen. */ |
11 | ||
12 | #define LO_MAGIC 0x01010101 | |
13 | #define HI_MAGIC 0x80808080 | |
14 | ||
15 | .text | |
16 | .align 4 | |
17 | .globl __memscan_zero, __memscan_generic | |
18 | .globl memscan | |
d3867f04 AV |
19 | EXPORT_SYMBOL(__memscan_zero) |
20 | EXPORT_SYMBOL(__memscan_generic) | |
1da177e4 LT |
21 | __memscan_zero: |
22 | /* %o0 = addr, %o1 = size */ | |
23 | cmp %o1, 0 | |
24 | bne,a 1f | |
25 | andcc %o0, 3, %g0 | |
26 | ||
27 | retl | |
28 | nop | |
29 | ||
30 | 1: | |
31 | be mzero_scan_word | |
32 | sethi %hi(HI_MAGIC), %g2 | |
33 | ||
34 | ldsb [%o0], %g3 | |
35 | mzero_still_not_word_aligned: | |
36 | cmp %g3, 0 | |
37 | bne 1f | |
38 | add %o0, 1, %o0 | |
39 | ||
40 | retl | |
41 | sub %o0, 1, %o0 | |
42 | ||
43 | 1: | |
44 | subcc %o1, 1, %o1 | |
45 | bne,a 1f | |
46 | andcc %o0, 3, %g0 | |
47 | ||
48 | retl | |
49 | nop | |
50 | ||
51 | 1: | |
52 | bne,a mzero_still_not_word_aligned | |
53 | ldsb [%o0], %g3 | |
54 | ||
55 | sethi %hi(HI_MAGIC), %g2 | |
56 | mzero_scan_word: | |
57 | or %g2, %lo(HI_MAGIC), %o3 | |
58 | sethi %hi(LO_MAGIC), %g3 | |
59 | or %g3, %lo(LO_MAGIC), %o2 | |
60 | mzero_next_word: | |
61 | ld [%o0], %g2 | |
62 | mzero_next_word_preloaded: | |
63 | sub %g2, %o2, %g2 | |
64 | mzero_next_word_preloaded_next: | |
65 | andcc %g2, %o3, %g0 | |
66 | bne mzero_byte_zero | |
67 | add %o0, 4, %o0 | |
68 | ||
69 | mzero_check_out_of_fuel: | |
70 | subcc %o1, 4, %o1 | |
71 | bg,a 1f | |
72 | ld [%o0], %g2 | |
73 | ||
74 | retl | |
75 | nop | |
76 | ||
77 | 1: | |
78 | b mzero_next_word_preloaded_next | |
79 | sub %g2, %o2, %g2 | |
80 | ||
81 | /* Check every byte. */ | |
82 | mzero_byte_zero: | |
83 | ldsb [%o0 - 4], %g2 | |
84 | cmp %g2, 0 | |
85 | bne mzero_byte_one | |
86 | sub %o0, 4, %g3 | |
87 | ||
88 | retl | |
89 | mov %g3, %o0 | |
90 | ||
91 | mzero_byte_one: | |
92 | ldsb [%o0 - 3], %g2 | |
93 | cmp %g2, 0 | |
94 | bne,a mzero_byte_two_and_three | |
95 | ldsb [%o0 - 2], %g2 | |
96 | ||
97 | retl | |
98 | sub %o0, 3, %o0 | |
99 | ||
100 | mzero_byte_two_and_three: | |
101 | cmp %g2, 0 | |
102 | bne,a 1f | |
103 | ldsb [%o0 - 1], %g2 | |
104 | ||
105 | retl | |
106 | sub %o0, 2, %o0 | |
107 | ||
108 | 1: | |
109 | cmp %g2, 0 | |
110 | bne,a mzero_next_word_preloaded | |
111 | ld [%o0], %g2 | |
112 | ||
113 | retl | |
114 | sub %o0, 1, %o0 | |
115 | ||
116 | mzero_found_it: | |
117 | retl | |
118 | sub %o0, 2, %o0 | |
119 | ||
120 | memscan: | |
121 | __memscan_generic: | |
122 | /* %o0 = addr, %o1 = c, %o2 = size */ | |
123 | cmp %o2, 0 | |
124 | bne,a 0f | |
125 | ldub [%o0], %g2 | |
126 | ||
127 | b,a 2f | |
128 | 1: | |
129 | ldub [%o0], %g2 | |
130 | 0: | |
131 | cmp %g2, %o1 | |
132 | be 2f | |
133 | addcc %o2, -1, %o2 | |
134 | bne 1b | |
135 | add %o0, 1, %o0 | |
136 | 2: | |
137 | retl | |
138 | nop |