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1da177e4 LT |
1 | /* -*- linux-c -*- ------------------------------------------------------- * |
2 | * | |
3 | * Copyright 2002 H. Peter Anvin - All Rights Reserved | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation, Inc., 53 Temple Place Ste 330, | |
93ed05e2 | 8 | * Boston MA 02111-1307, USA; either version 2 of the License, or |
1da177e4 LT |
9 | * (at your option) any later version; incorporated herein by reference. |
10 | * | |
11 | * ----------------------------------------------------------------------- */ | |
12 | ||
13 | /* | |
a8e026c7 | 14 | * raid6/algos.c |
1da177e4 LT |
15 | * |
16 | * Algorithm list and algorithm selection for RAID-6 | |
17 | */ | |
18 | ||
f701d589 | 19 | #include <linux/raid/pq.h> |
1da177e4 LT |
20 | #ifndef __KERNEL__ |
21 | #include <sys/mman.h> | |
d7e70ba4 | 22 | #include <stdio.h> |
f701d589 | 23 | #else |
f674ef7b | 24 | #include <linux/module.h> |
d5302fe4 | 25 | #include <linux/gfp.h> |
f701d589 DW |
26 | #if !RAID6_USE_EMPTY_ZERO_PAGE |
27 | /* In .bss so it's zeroed */ | |
28 | const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); | |
29 | EXPORT_SYMBOL(raid6_empty_zero_page); | |
30 | #endif | |
1da177e4 LT |
31 | #endif |
32 | ||
33 | struct raid6_calls raid6_call; | |
f701d589 | 34 | EXPORT_SYMBOL_GPL(raid6_call); |
1da177e4 | 35 | |
1da177e4 | 36 | const struct raid6_calls * const raid6_algos[] = { |
1da177e4 LT |
37 | #if defined(__ia64__) |
38 | &raid6_intx16, | |
39 | &raid6_intx32, | |
40 | #endif | |
ca5cd877 | 41 | #if defined(__i386__) && !defined(__arch_um__) |
1da177e4 LT |
42 | &raid6_mmxx1, |
43 | &raid6_mmxx2, | |
44 | &raid6_sse1x1, | |
45 | &raid6_sse1x2, | |
46 | &raid6_sse2x1, | |
47 | &raid6_sse2x2, | |
2c935842 YL |
48 | #ifdef CONFIG_AS_AVX2 |
49 | &raid6_avx2x1, | |
50 | &raid6_avx2x2, | |
51 | #endif | |
e0a491c1 GK |
52 | #ifdef CONFIG_AS_AVX512 |
53 | &raid6_avx512x1, | |
54 | &raid6_avx512x2, | |
55 | #endif | |
1da177e4 | 56 | #endif |
ca5cd877 | 57 | #if defined(__x86_64__) && !defined(__arch_um__) |
1da177e4 LT |
58 | &raid6_sse2x1, |
59 | &raid6_sse2x2, | |
60 | &raid6_sse2x4, | |
2c935842 YL |
61 | #ifdef CONFIG_AS_AVX2 |
62 | &raid6_avx2x1, | |
63 | &raid6_avx2x2, | |
64 | &raid6_avx2x4, | |
65 | #endif | |
e0a491c1 GK |
66 | #ifdef CONFIG_AS_AVX512 |
67 | &raid6_avx512x1, | |
68 | &raid6_avx512x2, | |
69 | &raid6_avx512x4, | |
70 | #endif | |
1da177e4 LT |
71 | #endif |
72 | #ifdef CONFIG_ALTIVEC | |
73 | &raid6_altivec1, | |
74 | &raid6_altivec2, | |
75 | &raid6_altivec4, | |
76 | &raid6_altivec8, | |
ae77cbc1 KS |
77 | #endif |
78 | #if defined(CONFIG_TILEGX) | |
79 | &raid6_tilegx8, | |
474fd6e8 MS |
80 | #endif |
81 | #if defined(CONFIG_S390) | |
82 | &raid6_s390vx8, | |
1da177e4 | 83 | #endif |
96e67703 JK |
84 | &raid6_intx1, |
85 | &raid6_intx2, | |
86 | &raid6_intx4, | |
87 | &raid6_intx8, | |
7d11965d AB |
88 | #ifdef CONFIG_KERNEL_MODE_NEON |
89 | &raid6_neonx1, | |
90 | &raid6_neonx2, | |
91 | &raid6_neonx4, | |
92 | &raid6_neonx8, | |
93 | #endif | |
1da177e4 LT |
94 | NULL |
95 | }; | |
96 | ||
048a8b8c JK |
97 | void (*raid6_2data_recov)(int, size_t, int, int, void **); |
98 | EXPORT_SYMBOL_GPL(raid6_2data_recov); | |
99 | ||
100 | void (*raid6_datap_recov)(int, size_t, int, void **); | |
101 | EXPORT_SYMBOL_GPL(raid6_datap_recov); | |
102 | ||
103 | const struct raid6_recov_calls *const raid6_recov_algos[] = { | |
13c520b2 GK |
104 | #ifdef CONFIG_AS_AVX512 |
105 | &raid6_recov_avx512, | |
106 | #endif | |
7056741f JK |
107 | #ifdef CONFIG_AS_AVX2 |
108 | &raid6_recov_avx2, | |
109 | #endif | |
75aaf4c3 | 110 | #ifdef CONFIG_AS_SSSE3 |
048a8b8c | 111 | &raid6_recov_ssse3, |
f5b55fa1 MS |
112 | #endif |
113 | #ifdef CONFIG_S390 | |
114 | &raid6_recov_s390xc, | |
048a8b8c JK |
115 | #endif |
116 | &raid6_recov_intx1, | |
117 | NULL | |
118 | }; | |
119 | ||
1da177e4 LT |
120 | #ifdef __KERNEL__ |
121 | #define RAID6_TIME_JIFFIES_LG2 4 | |
122 | #else | |
123 | /* Need more time to be stable in userspace */ | |
124 | #define RAID6_TIME_JIFFIES_LG2 9 | |
f701d589 | 125 | #define time_before(x, y) ((x) < (y)) |
1da177e4 LT |
126 | #endif |
127 | ||
96e67703 | 128 | static inline const struct raid6_recov_calls *raid6_choose_recov(void) |
048a8b8c JK |
129 | { |
130 | const struct raid6_recov_calls *const *algo; | |
131 | const struct raid6_recov_calls *best; | |
132 | ||
133 | for (best = NULL, algo = raid6_recov_algos; *algo; algo++) | |
134 | if (!best || (*algo)->priority > best->priority) | |
135 | if (!(*algo)->valid || (*algo)->valid()) | |
136 | best = *algo; | |
137 | ||
138 | if (best) { | |
139 | raid6_2data_recov = best->data2; | |
140 | raid6_datap_recov = best->datap; | |
141 | ||
b395f75e | 142 | pr_info("raid6: using %s recovery algorithm\n", best->name); |
048a8b8c | 143 | } else |
b395f75e | 144 | pr_err("raid6: Yikes! No recovery algorithm found!\n"); |
048a8b8c | 145 | |
96e67703 JK |
146 | return best; |
147 | } | |
1da177e4 | 148 | |
96e67703 JK |
149 | static inline const struct raid6_calls *raid6_choose_gen( |
150 | void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks) | |
1da177e4 | 151 | { |
fe5cbc6e MS |
152 | unsigned long perf, bestgenperf, bestxorperf, j0, j1; |
153 | int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */ | |
96e67703 JK |
154 | const struct raid6_calls *const *algo; |
155 | const struct raid6_calls *best; | |
1da177e4 | 156 | |
fe5cbc6e | 157 | for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) { |
96e67703 | 158 | if (!best || (*algo)->prefer >= best->prefer) { |
b79f99b5 CIK |
159 | /* 2 ^ (RAID6_TIME_JIFFIES_LG2 - 0.5) */ |
160 | const unsigned long raid6_time_jiffies = | |
161 | ((1 << RAID6_TIME_JIFFIES_LG2) * 181) >> 8; | |
162 | ||
96e67703 JK |
163 | if ((*algo)->valid && !(*algo)->valid()) |
164 | continue; | |
1da177e4 | 165 | |
1da177e4 LT |
166 | perf = 0; |
167 | ||
168 | preempt_disable(); | |
169 | j0 = jiffies; | |
96e67703 | 170 | while ((j1 = jiffies) == j0) |
1da177e4 | 171 | cpu_relax(); |
62b0559a | 172 | while (time_before(jiffies, |
b79f99b5 | 173 | j1 + raid6_time_jiffies)) { |
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, |
b79f99b5 CIK |
184 | (((perf*HZ) >> |
185 | (20-16+RAID6_TIME_JIFFIES_LG2)) * 1448) >> 10); | |
fe5cbc6e MS |
186 | |
187 | if (!(*algo)->xor_syndrome) | |
188 | continue; | |
189 | ||
190 | perf = 0; | |
191 | ||
192 | preempt_disable(); | |
193 | j0 = jiffies; | |
194 | while ((j1 = jiffies) == j0) | |
195 | cpu_relax(); | |
196 | while (time_before(jiffies, | |
b79f99b5 | 197 | j1 + raid6_time_jiffies)) { |
fe5cbc6e MS |
198 | (*algo)->xor_syndrome(disks, start, stop, |
199 | PAGE_SIZE, *dptrs); | |
200 | perf++; | |
201 | } | |
202 | preempt_enable(); | |
203 | ||
204 | if (best == *algo) | |
205 | bestxorperf = perf; | |
206 | ||
207 | pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name, | |
b79f99b5 CIK |
208 | (((perf*HZ) >> |
209 | (20-16+RAID6_TIME_JIFFIES_LG2+1)) * 1448) >> 10); | |
1da177e4 LT |
210 | } |
211 | } | |
212 | ||
a5d6839b | 213 | if (best) { |
fe5cbc6e | 214 | pr_info("raid6: using algorithm %s gen() %ld MB/s\n", |
1da177e4 | 215 | best->name, |
b79f99b5 CIK |
216 | (((bestgenperf*HZ) >> |
217 | (20-16+RAID6_TIME_JIFFIES_LG2)) * 1448) >> 10); | |
fe5cbc6e MS |
218 | if (best->xor_syndrome) |
219 | pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n", | |
b79f99b5 CIK |
220 | (((bestxorperf*HZ) >> |
221 | (20-16+RAID6_TIME_JIFFIES_LG2+1)) * 1448) >> 10); | |
a5d6839b AB |
222 | raid6_call = *best; |
223 | } else | |
b395f75e | 224 | pr_err("raid6: Yikes! No algorithm found!\n"); |
1da177e4 | 225 | |
96e67703 JK |
226 | return best; |
227 | } | |
228 | ||
229 | ||
230 | /* Try to pick the best algorithm */ | |
231 | /* This code uses the gfmul table as convenient data set to abuse */ | |
232 | ||
233 | int __init raid6_select_algo(void) | |
234 | { | |
235 | const int disks = (65536/PAGE_SIZE)+2; | |
236 | ||
237 | const struct raid6_calls *gen_best; | |
238 | const struct raid6_recov_calls *rec_best; | |
239 | char *syndromes; | |
240 | void *dptrs[(65536/PAGE_SIZE)+2]; | |
241 | int i; | |
242 | ||
243 | for (i = 0; i < disks-2; i++) | |
244 | dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i; | |
245 | ||
246 | /* Normal code - use a 2-page allocation to avoid D$ conflict */ | |
247 | syndromes = (void *) __get_free_pages(GFP_KERNEL, 1); | |
248 | ||
249 | if (!syndromes) { | |
b395f75e | 250 | pr_err("raid6: Yikes! No memory available.\n"); |
96e67703 JK |
251 | return -ENOMEM; |
252 | } | |
253 | ||
254 | dptrs[disks-2] = syndromes; | |
255 | dptrs[disks-1] = syndromes + PAGE_SIZE; | |
256 | ||
257 | /* select raid gen_syndrome function */ | |
258 | gen_best = raid6_choose_gen(&dptrs, disks); | |
1da177e4 | 259 | |
048a8b8c | 260 | /* select raid recover functions */ |
96e67703 JK |
261 | rec_best = raid6_choose_recov(); |
262 | ||
263 | free_pages((unsigned long)syndromes, 1); | |
048a8b8c | 264 | |
96e67703 | 265 | return gen_best && rec_best ? 0 : -EINVAL; |
1da177e4 | 266 | } |
f701d589 DW |
267 | |
268 | static void raid6_exit(void) | |
269 | { | |
270 | do { } while (0); | |
271 | } | |
272 | ||
273 | subsys_initcall(raid6_select_algo); | |
274 | module_exit(raid6_exit); | |
275 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 276 | MODULE_DESCRIPTION("RAID6 Q-syndrome calculations"); |