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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 | |
1da177e4 | 52 | #endif |
ca5cd877 | 53 | #if defined(__x86_64__) && !defined(__arch_um__) |
1da177e4 LT |
54 | &raid6_sse2x1, |
55 | &raid6_sse2x2, | |
56 | &raid6_sse2x4, | |
2c935842 YL |
57 | #ifdef CONFIG_AS_AVX2 |
58 | &raid6_avx2x1, | |
59 | &raid6_avx2x2, | |
60 | &raid6_avx2x4, | |
61 | #endif | |
1da177e4 LT |
62 | #endif |
63 | #ifdef CONFIG_ALTIVEC | |
64 | &raid6_altivec1, | |
65 | &raid6_altivec2, | |
66 | &raid6_altivec4, | |
67 | &raid6_altivec8, | |
68 | #endif | |
96e67703 JK |
69 | &raid6_intx1, |
70 | &raid6_intx2, | |
71 | &raid6_intx4, | |
72 | &raid6_intx8, | |
1da177e4 LT |
73 | NULL |
74 | }; | |
75 | ||
048a8b8c JK |
76 | void (*raid6_2data_recov)(int, size_t, int, int, void **); |
77 | EXPORT_SYMBOL_GPL(raid6_2data_recov); | |
78 | ||
79 | void (*raid6_datap_recov)(int, size_t, int, void **); | |
80 | EXPORT_SYMBOL_GPL(raid6_datap_recov); | |
81 | ||
82 | const struct raid6_recov_calls *const raid6_recov_algos[] = { | |
83 | #if (defined(__i386__) || defined(__x86_64__)) && !defined(__arch_um__) | |
7056741f JK |
84 | #ifdef CONFIG_AS_AVX2 |
85 | &raid6_recov_avx2, | |
86 | #endif | |
048a8b8c JK |
87 | &raid6_recov_ssse3, |
88 | #endif | |
89 | &raid6_recov_intx1, | |
90 | NULL | |
91 | }; | |
92 | ||
1da177e4 LT |
93 | #ifdef __KERNEL__ |
94 | #define RAID6_TIME_JIFFIES_LG2 4 | |
95 | #else | |
96 | /* Need more time to be stable in userspace */ | |
97 | #define RAID6_TIME_JIFFIES_LG2 9 | |
f701d589 | 98 | #define time_before(x, y) ((x) < (y)) |
1da177e4 LT |
99 | #endif |
100 | ||
96e67703 | 101 | static inline const struct raid6_recov_calls *raid6_choose_recov(void) |
048a8b8c JK |
102 | { |
103 | const struct raid6_recov_calls *const *algo; | |
104 | const struct raid6_recov_calls *best; | |
105 | ||
106 | for (best = NULL, algo = raid6_recov_algos; *algo; algo++) | |
107 | if (!best || (*algo)->priority > best->priority) | |
108 | if (!(*algo)->valid || (*algo)->valid()) | |
109 | best = *algo; | |
110 | ||
111 | if (best) { | |
112 | raid6_2data_recov = best->data2; | |
113 | raid6_datap_recov = best->datap; | |
114 | ||
115 | printk("raid6: using %s recovery algorithm\n", best->name); | |
116 | } else | |
117 | printk("raid6: Yikes! No recovery algorithm found!\n"); | |
048a8b8c | 118 | |
96e67703 JK |
119 | return best; |
120 | } | |
1da177e4 | 121 | |
96e67703 JK |
122 | static inline const struct raid6_calls *raid6_choose_gen( |
123 | void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks) | |
1da177e4 | 124 | { |
96e67703 JK |
125 | unsigned long perf, bestperf, j0, j1; |
126 | const struct raid6_calls *const *algo; | |
127 | const struct raid6_calls *best; | |
1da177e4 | 128 | |
96e67703 JK |
129 | for (bestperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) { |
130 | if (!best || (*algo)->prefer >= best->prefer) { | |
131 | if ((*algo)->valid && !(*algo)->valid()) | |
132 | continue; | |
1da177e4 | 133 | |
1da177e4 LT |
134 | perf = 0; |
135 | ||
136 | preempt_disable(); | |
137 | j0 = jiffies; | |
96e67703 | 138 | while ((j1 = jiffies) == j0) |
1da177e4 | 139 | cpu_relax(); |
62b0559a JL |
140 | while (time_before(jiffies, |
141 | j1 + (1<<RAID6_TIME_JIFFIES_LG2))) { | |
96e67703 | 142 | (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs); |
1da177e4 LT |
143 | perf++; |
144 | } | |
145 | preempt_enable(); | |
146 | ||
96e67703 | 147 | if (perf > bestperf) { |
1da177e4 | 148 | bestperf = perf; |
96e67703 | 149 | best = *algo; |
1da177e4 LT |
150 | } |
151 | printk("raid6: %-8s %5ld MB/s\n", (*algo)->name, | |
152 | (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); | |
153 | } | |
154 | } | |
155 | ||
a5d6839b | 156 | if (best) { |
1da177e4 LT |
157 | printk("raid6: using algorithm %s (%ld MB/s)\n", |
158 | best->name, | |
159 | (bestperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); | |
a5d6839b AB |
160 | raid6_call = *best; |
161 | } else | |
1da177e4 LT |
162 | printk("raid6: Yikes! No algorithm found!\n"); |
163 | ||
96e67703 JK |
164 | return best; |
165 | } | |
166 | ||
167 | ||
168 | /* Try to pick the best algorithm */ | |
169 | /* This code uses the gfmul table as convenient data set to abuse */ | |
170 | ||
171 | int __init raid6_select_algo(void) | |
172 | { | |
173 | const int disks = (65536/PAGE_SIZE)+2; | |
174 | ||
175 | const struct raid6_calls *gen_best; | |
176 | const struct raid6_recov_calls *rec_best; | |
177 | char *syndromes; | |
178 | void *dptrs[(65536/PAGE_SIZE)+2]; | |
179 | int i; | |
180 | ||
181 | for (i = 0; i < disks-2; i++) | |
182 | dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i; | |
183 | ||
184 | /* Normal code - use a 2-page allocation to avoid D$ conflict */ | |
185 | syndromes = (void *) __get_free_pages(GFP_KERNEL, 1); | |
186 | ||
187 | if (!syndromes) { | |
188 | printk("raid6: Yikes! No memory available.\n"); | |
189 | return -ENOMEM; | |
190 | } | |
191 | ||
192 | dptrs[disks-2] = syndromes; | |
193 | dptrs[disks-1] = syndromes + PAGE_SIZE; | |
194 | ||
195 | /* select raid gen_syndrome function */ | |
196 | gen_best = raid6_choose_gen(&dptrs, disks); | |
1da177e4 | 197 | |
048a8b8c | 198 | /* select raid recover functions */ |
96e67703 JK |
199 | rec_best = raid6_choose_recov(); |
200 | ||
201 | free_pages((unsigned long)syndromes, 1); | |
048a8b8c | 202 | |
96e67703 | 203 | return gen_best && rec_best ? 0 : -EINVAL; |
1da177e4 | 204 | } |
f701d589 DW |
205 | |
206 | static void raid6_exit(void) | |
207 | { | |
208 | do { } while (0); | |
209 | } | |
210 | ||
211 | subsys_initcall(raid6_select_algo); | |
212 | module_exit(raid6_exit); | |
213 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 214 | MODULE_DESCRIPTION("RAID6 Q-syndrome calculations"); |