Commit | Line | Data |
---|---|---|
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, | |
48 | #endif | |
ca5cd877 | 49 | #if defined(__x86_64__) && !defined(__arch_um__) |
1da177e4 LT |
50 | &raid6_sse2x1, |
51 | &raid6_sse2x2, | |
52 | &raid6_sse2x4, | |
53 | #endif | |
54 | #ifdef CONFIG_ALTIVEC | |
55 | &raid6_altivec1, | |
56 | &raid6_altivec2, | |
57 | &raid6_altivec4, | |
58 | &raid6_altivec8, | |
59 | #endif | |
96e67703 JK |
60 | &raid6_intx1, |
61 | &raid6_intx2, | |
62 | &raid6_intx4, | |
63 | &raid6_intx8, | |
1da177e4 LT |
64 | NULL |
65 | }; | |
66 | ||
048a8b8c JK |
67 | void (*raid6_2data_recov)(int, size_t, int, int, void **); |
68 | EXPORT_SYMBOL_GPL(raid6_2data_recov); | |
69 | ||
70 | void (*raid6_datap_recov)(int, size_t, int, void **); | |
71 | EXPORT_SYMBOL_GPL(raid6_datap_recov); | |
72 | ||
73 | const struct raid6_recov_calls *const raid6_recov_algos[] = { | |
74 | #if (defined(__i386__) || defined(__x86_64__)) && !defined(__arch_um__) | |
75 | &raid6_recov_ssse3, | |
76 | #endif | |
77 | &raid6_recov_intx1, | |
78 | NULL | |
79 | }; | |
80 | ||
1da177e4 LT |
81 | #ifdef __KERNEL__ |
82 | #define RAID6_TIME_JIFFIES_LG2 4 | |
83 | #else | |
84 | /* Need more time to be stable in userspace */ | |
85 | #define RAID6_TIME_JIFFIES_LG2 9 | |
f701d589 | 86 | #define time_before(x, y) ((x) < (y)) |
1da177e4 LT |
87 | #endif |
88 | ||
96e67703 | 89 | static inline const struct raid6_recov_calls *raid6_choose_recov(void) |
048a8b8c JK |
90 | { |
91 | const struct raid6_recov_calls *const *algo; | |
92 | const struct raid6_recov_calls *best; | |
93 | ||
94 | for (best = NULL, algo = raid6_recov_algos; *algo; algo++) | |
95 | if (!best || (*algo)->priority > best->priority) | |
96 | if (!(*algo)->valid || (*algo)->valid()) | |
97 | best = *algo; | |
98 | ||
99 | if (best) { | |
100 | raid6_2data_recov = best->data2; | |
101 | raid6_datap_recov = best->datap; | |
102 | ||
103 | printk("raid6: using %s recovery algorithm\n", best->name); | |
104 | } else | |
105 | printk("raid6: Yikes! No recovery algorithm found!\n"); | |
048a8b8c | 106 | |
96e67703 JK |
107 | return best; |
108 | } | |
1da177e4 | 109 | |
96e67703 JK |
110 | static inline const struct raid6_calls *raid6_choose_gen( |
111 | void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks) | |
1da177e4 | 112 | { |
96e67703 JK |
113 | unsigned long perf, bestperf, j0, j1; |
114 | const struct raid6_calls *const *algo; | |
115 | const struct raid6_calls *best; | |
1da177e4 | 116 | |
96e67703 JK |
117 | for (bestperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) { |
118 | if (!best || (*algo)->prefer >= best->prefer) { | |
119 | if ((*algo)->valid && !(*algo)->valid()) | |
120 | continue; | |
1da177e4 | 121 | |
1da177e4 LT |
122 | perf = 0; |
123 | ||
124 | preempt_disable(); | |
125 | j0 = jiffies; | |
96e67703 | 126 | while ((j1 = jiffies) == j0) |
1da177e4 | 127 | cpu_relax(); |
62b0559a JL |
128 | while (time_before(jiffies, |
129 | j1 + (1<<RAID6_TIME_JIFFIES_LG2))) { | |
96e67703 | 130 | (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs); |
1da177e4 LT |
131 | perf++; |
132 | } | |
133 | preempt_enable(); | |
134 | ||
96e67703 | 135 | if (perf > bestperf) { |
1da177e4 | 136 | bestperf = perf; |
96e67703 | 137 | best = *algo; |
1da177e4 LT |
138 | } |
139 | printk("raid6: %-8s %5ld MB/s\n", (*algo)->name, | |
140 | (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); | |
141 | } | |
142 | } | |
143 | ||
a5d6839b | 144 | if (best) { |
1da177e4 LT |
145 | printk("raid6: using algorithm %s (%ld MB/s)\n", |
146 | best->name, | |
147 | (bestperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); | |
a5d6839b AB |
148 | raid6_call = *best; |
149 | } else | |
1da177e4 LT |
150 | printk("raid6: Yikes! No algorithm found!\n"); |
151 | ||
96e67703 JK |
152 | return best; |
153 | } | |
154 | ||
155 | ||
156 | /* Try to pick the best algorithm */ | |
157 | /* This code uses the gfmul table as convenient data set to abuse */ | |
158 | ||
159 | int __init raid6_select_algo(void) | |
160 | { | |
161 | const int disks = (65536/PAGE_SIZE)+2; | |
162 | ||
163 | const struct raid6_calls *gen_best; | |
164 | const struct raid6_recov_calls *rec_best; | |
165 | char *syndromes; | |
166 | void *dptrs[(65536/PAGE_SIZE)+2]; | |
167 | int i; | |
168 | ||
169 | for (i = 0; i < disks-2; i++) | |
170 | dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i; | |
171 | ||
172 | /* Normal code - use a 2-page allocation to avoid D$ conflict */ | |
173 | syndromes = (void *) __get_free_pages(GFP_KERNEL, 1); | |
174 | ||
175 | if (!syndromes) { | |
176 | printk("raid6: Yikes! No memory available.\n"); | |
177 | return -ENOMEM; | |
178 | } | |
179 | ||
180 | dptrs[disks-2] = syndromes; | |
181 | dptrs[disks-1] = syndromes + PAGE_SIZE; | |
182 | ||
183 | /* select raid gen_syndrome function */ | |
184 | gen_best = raid6_choose_gen(&dptrs, disks); | |
1da177e4 | 185 | |
048a8b8c | 186 | /* select raid recover functions */ |
96e67703 JK |
187 | rec_best = raid6_choose_recov(); |
188 | ||
189 | free_pages((unsigned long)syndromes, 1); | |
048a8b8c | 190 | |
96e67703 | 191 | return gen_best && rec_best ? 0 : -EINVAL; |
1da177e4 | 192 | } |
f701d589 DW |
193 | |
194 | static void raid6_exit(void) | |
195 | { | |
196 | do { } while (0); | |
197 | } | |
198 | ||
199 | subsys_initcall(raid6_select_algo); | |
200 | module_exit(raid6_exit); | |
201 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 202 | MODULE_DESCRIPTION("RAID6 Q-syndrome calculations"); |