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dd165a65 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* -*- linux-c -*- ------------------------------------------------------- * |
3 | * | |
4 | * Copyright 2002 H. Peter Anvin - All Rights Reserved | |
5 | * | |
1da177e4 LT |
6 | * ----------------------------------------------------------------------- */ |
7 | ||
8 | /* | |
a8e026c7 | 9 | * raid6/algos.c |
1da177e4 LT |
10 | * |
11 | * Algorithm list and algorithm selection for RAID-6 | |
12 | */ | |
13 | ||
f701d589 | 14 | #include <linux/raid/pq.h> |
1da177e4 LT |
15 | #ifndef __KERNEL__ |
16 | #include <sys/mman.h> | |
d7e70ba4 | 17 | #include <stdio.h> |
f701d589 | 18 | #else |
f674ef7b | 19 | #include <linux/module.h> |
d5302fe4 | 20 | #include <linux/gfp.h> |
f701d589 DW |
21 | #if !RAID6_USE_EMPTY_ZERO_PAGE |
22 | /* In .bss so it's zeroed */ | |
23 | const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); | |
24 | EXPORT_SYMBOL(raid6_empty_zero_page); | |
25 | #endif | |
1da177e4 LT |
26 | #endif |
27 | ||
28 | struct raid6_calls raid6_call; | |
f701d589 | 29 | EXPORT_SYMBOL_GPL(raid6_call); |
1da177e4 | 30 | |
1da177e4 | 31 | const struct raid6_calls * const raid6_algos[] = { |
ca5cd877 | 32 | #if defined(__i386__) && !defined(__arch_um__) |
e0a491c1 | 33 | #ifdef CONFIG_AS_AVX512 |
e0a491c1 | 34 | &raid6_avx512x2, |
0437de4f | 35 | &raid6_avx512x1, |
e0a491c1 | 36 | #endif |
2c935842 | 37 | #ifdef CONFIG_AS_AVX2 |
2c935842 | 38 | &raid6_avx2x2, |
0437de4f | 39 | &raid6_avx2x1, |
2c935842 | 40 | #endif |
0437de4f DV |
41 | &raid6_sse2x2, |
42 | &raid6_sse2x1, | |
43 | &raid6_sse1x2, | |
44 | &raid6_sse1x1, | |
45 | &raid6_mmxx2, | |
46 | &raid6_mmxx1, | |
47 | #endif | |
48 | #if defined(__x86_64__) && !defined(__arch_um__) | |
e0a491c1 | 49 | #ifdef CONFIG_AS_AVX512 |
e0a491c1 | 50 | &raid6_avx512x4, |
0437de4f DV |
51 | &raid6_avx512x2, |
52 | &raid6_avx512x1, | |
53 | #endif | |
54 | #ifdef CONFIG_AS_AVX2 | |
55 | &raid6_avx2x4, | |
56 | &raid6_avx2x2, | |
57 | &raid6_avx2x1, | |
e0a491c1 | 58 | #endif |
0437de4f DV |
59 | &raid6_sse2x4, |
60 | &raid6_sse2x2, | |
61 | &raid6_sse2x1, | |
1da177e4 LT |
62 | #endif |
63 | #ifdef CONFIG_ALTIVEC | |
751ba79c | 64 | &raid6_vpermxor8, |
0437de4f DV |
65 | &raid6_vpermxor4, |
66 | &raid6_vpermxor2, | |
67 | &raid6_vpermxor1, | |
68 | &raid6_altivec8, | |
69 | &raid6_altivec4, | |
70 | &raid6_altivec2, | |
71 | &raid6_altivec1, | |
ae77cbc1 | 72 | #endif |
474fd6e8 MS |
73 | #if defined(CONFIG_S390) |
74 | &raid6_s390vx8, | |
1da177e4 | 75 | #endif |
7d11965d | 76 | #ifdef CONFIG_KERNEL_MODE_NEON |
7d11965d | 77 | &raid6_neonx8, |
0437de4f DV |
78 | &raid6_neonx4, |
79 | &raid6_neonx2, | |
80 | &raid6_neonx1, | |
81 | #endif | |
82 | #if defined(__ia64__) | |
83 | &raid6_intx32, | |
84 | &raid6_intx16, | |
7d11965d | 85 | #endif |
0437de4f DV |
86 | &raid6_intx8, |
87 | &raid6_intx4, | |
88 | &raid6_intx2, | |
89 | &raid6_intx1, | |
1da177e4 LT |
90 | NULL |
91 | }; | |
92 | ||
048a8b8c JK |
93 | void (*raid6_2data_recov)(int, size_t, int, int, void **); |
94 | EXPORT_SYMBOL_GPL(raid6_2data_recov); | |
95 | ||
96 | void (*raid6_datap_recov)(int, size_t, int, void **); | |
97 | EXPORT_SYMBOL_GPL(raid6_datap_recov); | |
98 | ||
99 | const struct raid6_recov_calls *const raid6_recov_algos[] = { | |
13c520b2 GK |
100 | #ifdef CONFIG_AS_AVX512 |
101 | &raid6_recov_avx512, | |
102 | #endif | |
7056741f JK |
103 | #ifdef CONFIG_AS_AVX2 |
104 | &raid6_recov_avx2, | |
105 | #endif | |
75aaf4c3 | 106 | #ifdef CONFIG_AS_SSSE3 |
048a8b8c | 107 | &raid6_recov_ssse3, |
f5b55fa1 MS |
108 | #endif |
109 | #ifdef CONFIG_S390 | |
110 | &raid6_recov_s390xc, | |
6ec4e251 AB |
111 | #endif |
112 | #if defined(CONFIG_KERNEL_MODE_NEON) | |
113 | &raid6_recov_neon, | |
048a8b8c JK |
114 | #endif |
115 | &raid6_recov_intx1, | |
116 | NULL | |
117 | }; | |
118 | ||
1da177e4 LT |
119 | #ifdef __KERNEL__ |
120 | #define RAID6_TIME_JIFFIES_LG2 4 | |
121 | #else | |
122 | /* Need more time to be stable in userspace */ | |
123 | #define RAID6_TIME_JIFFIES_LG2 9 | |
f701d589 | 124 | #define time_before(x, y) ((x) < (y)) |
1da177e4 LT |
125 | #endif |
126 | ||
96e67703 | 127 | static inline const struct raid6_recov_calls *raid6_choose_recov(void) |
048a8b8c JK |
128 | { |
129 | const struct raid6_recov_calls *const *algo; | |
130 | const struct raid6_recov_calls *best; | |
131 | ||
132 | for (best = NULL, algo = raid6_recov_algos; *algo; algo++) | |
133 | if (!best || (*algo)->priority > best->priority) | |
134 | if (!(*algo)->valid || (*algo)->valid()) | |
135 | best = *algo; | |
136 | ||
137 | if (best) { | |
138 | raid6_2data_recov = best->data2; | |
139 | raid6_datap_recov = best->datap; | |
140 | ||
b395f75e | 141 | pr_info("raid6: using %s recovery algorithm\n", best->name); |
048a8b8c | 142 | } else |
b395f75e | 143 | pr_err("raid6: Yikes! No recovery algorithm found!\n"); |
048a8b8c | 144 | |
96e67703 JK |
145 | return best; |
146 | } | |
1da177e4 | 147 | |
96e67703 JK |
148 | static inline const struct raid6_calls *raid6_choose_gen( |
149 | void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks) | |
1da177e4 | 150 | { |
fe5cbc6e MS |
151 | unsigned long perf, bestgenperf, bestxorperf, j0, j1; |
152 | int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */ | |
96e67703 JK |
153 | const struct raid6_calls *const *algo; |
154 | const struct raid6_calls *best; | |
1da177e4 | 155 | |
fe5cbc6e | 156 | for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) { |
96e67703 JK |
157 | if (!best || (*algo)->prefer >= best->prefer) { |
158 | if ((*algo)->valid && !(*algo)->valid()) | |
159 | continue; | |
1da177e4 | 160 | |
be85f93a DV |
161 | if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) { |
162 | best = *algo; | |
163 | break; | |
164 | } | |
165 | ||
1da177e4 LT |
166 | perf = 0; |
167 | ||
168 | preempt_disable(); | |
169 | j0 = jiffies; | |
96e67703 | 170 | while ((j1 = jiffies) == j0) |
1da177e4 | 171 | cpu_relax(); |
62b0559a JL |
172 | while (time_before(jiffies, |
173 | j1 + (1<<RAID6_TIME_JIFFIES_LG2))) { | |
96e67703 | 174 | (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs); |
1da177e4 LT |
175 | perf++; |
176 | } | |
177 | preempt_enable(); | |
178 | ||
fe5cbc6e MS |
179 | if (perf > bestgenperf) { |
180 | bestgenperf = perf; | |
96e67703 | 181 | best = *algo; |
1da177e4 | 182 | } |
fe5cbc6e | 183 | pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name, |
1da177e4 | 184 | (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); |
fe5cbc6e MS |
185 | |
186 | if (!(*algo)->xor_syndrome) | |
187 | continue; | |
188 | ||
189 | perf = 0; | |
190 | ||
191 | preempt_disable(); | |
192 | j0 = jiffies; | |
193 | while ((j1 = jiffies) == j0) | |
194 | cpu_relax(); | |
195 | while (time_before(jiffies, | |
196 | j1 + (1<<RAID6_TIME_JIFFIES_LG2))) { | |
197 | (*algo)->xor_syndrome(disks, start, stop, | |
198 | PAGE_SIZE, *dptrs); | |
199 | perf++; | |
200 | } | |
201 | preempt_enable(); | |
202 | ||
203 | if (best == *algo) | |
204 | bestxorperf = perf; | |
205 | ||
206 | pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name, | |
207 | (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1)); | |
1da177e4 LT |
208 | } |
209 | } | |
210 | ||
a5d6839b | 211 | if (best) { |
fe5cbc6e | 212 | pr_info("raid6: using algorithm %s gen() %ld MB/s\n", |
1da177e4 | 213 | best->name, |
fe5cbc6e MS |
214 | (bestgenperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); |
215 | if (best->xor_syndrome) | |
216 | pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n", | |
217 | (bestxorperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1)); | |
a5d6839b AB |
218 | raid6_call = *best; |
219 | } else | |
b395f75e | 220 | pr_err("raid6: Yikes! No algorithm found!\n"); |
1da177e4 | 221 | |
96e67703 JK |
222 | return best; |
223 | } | |
224 | ||
225 | ||
226 | /* Try to pick the best algorithm */ | |
227 | /* This code uses the gfmul table as convenient data set to abuse */ | |
228 | ||
229 | int __init raid6_select_algo(void) | |
230 | { | |
231 | const int disks = (65536/PAGE_SIZE)+2; | |
232 | ||
233 | const struct raid6_calls *gen_best; | |
234 | const struct raid6_recov_calls *rec_best; | |
235 | char *syndromes; | |
236 | void *dptrs[(65536/PAGE_SIZE)+2]; | |
237 | int i; | |
238 | ||
239 | for (i = 0; i < disks-2; i++) | |
240 | dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i; | |
241 | ||
242 | /* Normal code - use a 2-page allocation to avoid D$ conflict */ | |
243 | syndromes = (void *) __get_free_pages(GFP_KERNEL, 1); | |
244 | ||
245 | if (!syndromes) { | |
b395f75e | 246 | pr_err("raid6: Yikes! No memory available.\n"); |
96e67703 JK |
247 | return -ENOMEM; |
248 | } | |
249 | ||
250 | dptrs[disks-2] = syndromes; | |
251 | dptrs[disks-1] = syndromes + PAGE_SIZE; | |
252 | ||
253 | /* select raid gen_syndrome function */ | |
254 | gen_best = raid6_choose_gen(&dptrs, disks); | |
1da177e4 | 255 | |
048a8b8c | 256 | /* select raid recover functions */ |
96e67703 JK |
257 | rec_best = raid6_choose_recov(); |
258 | ||
259 | free_pages((unsigned long)syndromes, 1); | |
048a8b8c | 260 | |
96e67703 | 261 | return gen_best && rec_best ? 0 : -EINVAL; |
1da177e4 | 262 | } |
f701d589 DW |
263 | |
264 | static void raid6_exit(void) | |
265 | { | |
266 | do { } while (0); | |
267 | } | |
268 | ||
269 | subsys_initcall(raid6_select_algo); | |
270 | module_exit(raid6_exit); | |
271 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 272 | MODULE_DESCRIPTION("RAID6 Q-syndrome calculations"); |