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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,
8 * Boston MA 02111-1307, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13/*
14 * raid6/algos.c
15 *
16 * Algorithm list and algorithm selection for RAID-6
17 */
18
19#include <linux/raid/pq.h>
20#ifndef __KERNEL__
21#include <sys/mman.h>
22#include <stdio.h>
23#else
24#include <linux/module.h>
25#include <linux/gfp.h>
26#if !RAID6_USE_EMPTY_ZERO_PAGE
27/* In .bss so it's zeroed */
28const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
29EXPORT_SYMBOL(raid6_empty_zero_page);
30#endif
31#endif
32
33struct raid6_calls raid6_call;
34EXPORT_SYMBOL_GPL(raid6_call);
35
36const struct raid6_calls * const raid6_algos[] = {
37#if defined(__ia64__)
38 &raid6_intx16,
39 &raid6_intx32,
40#endif
41#if defined(__i386__) && !defined(__arch_um__)
42 &raid6_mmxx1,
43 &raid6_mmxx2,
44 &raid6_sse1x1,
45 &raid6_sse1x2,
46 &raid6_sse2x1,
47 &raid6_sse2x2,
48#ifdef CONFIG_AS_AVX2
49 &raid6_avx2x1,
50 &raid6_avx2x2,
51#endif
52#ifdef CONFIG_AS_AVX512
53 &raid6_avx512x1,
54 &raid6_avx512x2,
55#endif
56#endif
57#if defined(__x86_64__) && !defined(__arch_um__)
58 &raid6_sse2x1,
59 &raid6_sse2x2,
60 &raid6_sse2x4,
61#ifdef CONFIG_AS_AVX2
62 &raid6_avx2x1,
63 &raid6_avx2x2,
64 &raid6_avx2x4,
65#endif
66#ifdef CONFIG_AS_AVX512
67 &raid6_avx512x1,
68 &raid6_avx512x2,
69 &raid6_avx512x4,
70#endif
71#endif
72#ifdef CONFIG_ALTIVEC
73 &raid6_altivec1,
74 &raid6_altivec2,
75 &raid6_altivec4,
76 &raid6_altivec8,
77 &raid6_vpermxor1,
78 &raid6_vpermxor2,
79 &raid6_vpermxor4,
80 &raid6_vpermxor8,
81#endif
82#if defined(CONFIG_S390)
83 &raid6_s390vx8,
84#endif
85 &raid6_intx1,
86 &raid6_intx2,
87 &raid6_intx4,
88 &raid6_intx8,
89#ifdef CONFIG_KERNEL_MODE_NEON
90 &raid6_neonx1,
91 &raid6_neonx2,
92 &raid6_neonx4,
93 &raid6_neonx8,
94#endif
95 NULL
96};
97
98void (*raid6_2data_recov)(int, size_t, int, int, void **);
99EXPORT_SYMBOL_GPL(raid6_2data_recov);
100
101void (*raid6_datap_recov)(int, size_t, int, void **);
102EXPORT_SYMBOL_GPL(raid6_datap_recov);
103
104const struct raid6_recov_calls *const raid6_recov_algos[] = {
105#ifdef CONFIG_AS_AVX512
106 &raid6_recov_avx512,
107#endif
108#ifdef CONFIG_AS_AVX2
109 &raid6_recov_avx2,
110#endif
111#ifdef CONFIG_AS_SSSE3
112 &raid6_recov_ssse3,
113#endif
114#ifdef CONFIG_S390
115 &raid6_recov_s390xc,
116#endif
117#if defined(CONFIG_KERNEL_MODE_NEON)
118 &raid6_recov_neon,
119#endif
120 &raid6_recov_intx1,
121 NULL
122};
123
124#ifdef __KERNEL__
125#define RAID6_TIME_JIFFIES_LG2 4
126#else
127/* Need more time to be stable in userspace */
128#define RAID6_TIME_JIFFIES_LG2 9
129#define time_before(x, y) ((x) < (y))
130#endif
131
132static inline const struct raid6_recov_calls *raid6_choose_recov(void)
133{
134 const struct raid6_recov_calls *const *algo;
135 const struct raid6_recov_calls *best;
136
137 for (best = NULL, algo = raid6_recov_algos; *algo; algo++)
138 if (!best || (*algo)->priority > best->priority)
139 if (!(*algo)->valid || (*algo)->valid())
140 best = *algo;
141
142 if (best) {
143 raid6_2data_recov = best->data2;
144 raid6_datap_recov = best->datap;
145
146 pr_info("raid6: using %s recovery algorithm\n", best->name);
147 } else
148 pr_err("raid6: Yikes! No recovery algorithm found!\n");
149
150 return best;
151}
152
153static inline const struct raid6_calls *raid6_choose_gen(
154 void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks)
155{
156 unsigned long perf, bestgenperf, bestxorperf, j0, j1;
157 int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */
158 const struct raid6_calls *const *algo;
159 const struct raid6_calls *best;
160
161 for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) {
162 if (!best || (*algo)->prefer >= best->prefer) {
163 if ((*algo)->valid && !(*algo)->valid())
164 continue;
165
166 perf = 0;
167
168 preempt_disable();
169 j0 = jiffies;
170 while ((j1 = jiffies) == j0)
171 cpu_relax();
172 while (time_before(jiffies,
173 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
174 (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs);
175 perf++;
176 }
177 preempt_enable();
178
179 if (perf > bestgenperf) {
180 bestgenperf = perf;
181 best = *algo;
182 }
183 pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name,
184 (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
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));
208 }
209 }
210
211 if (best) {
212 pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
213 best->name,
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));
218 raid6_call = *best;
219 } else
220 pr_err("raid6: Yikes! No algorithm found!\n");
221
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
229int __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) {
246 pr_err("raid6: Yikes! No memory available.\n");
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);
255
256 /* select raid recover functions */
257 rec_best = raid6_choose_recov();
258
259 free_pages((unsigned long)syndromes, 1);
260
261 return gen_best && rec_best ? 0 : -EINVAL;
262}
263
264static void raid6_exit(void)
265{
266 do { } while (0);
267}
268
269subsys_initcall(raid6_select_algo);
270module_exit(raid6_exit);
271MODULE_LICENSE("GPL");
272MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");
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,
8 * Boston MA 02111-1307, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13/*
14 * raid6/algos.c
15 *
16 * Algorithm list and algorithm selection for RAID-6
17 */
18
19#include <linux/raid/pq.h>
20#ifndef __KERNEL__
21#include <sys/mman.h>
22#include <stdio.h>
23#else
24#include <linux/gfp.h>
25#if !RAID6_USE_EMPTY_ZERO_PAGE
26/* In .bss so it's zeroed */
27const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
28EXPORT_SYMBOL(raid6_empty_zero_page);
29#endif
30#endif
31
32struct raid6_calls raid6_call;
33EXPORT_SYMBOL_GPL(raid6_call);
34
35const struct raid6_calls * const raid6_algos[] = {
36 &raid6_intx1,
37 &raid6_intx2,
38 &raid6_intx4,
39 &raid6_intx8,
40#if defined(__ia64__)
41 &raid6_intx16,
42 &raid6_intx32,
43#endif
44#if defined(__i386__) && !defined(__arch_um__)
45 &raid6_mmxx1,
46 &raid6_mmxx2,
47 &raid6_sse1x1,
48 &raid6_sse1x2,
49 &raid6_sse2x1,
50 &raid6_sse2x2,
51#endif
52#if defined(__x86_64__) && !defined(__arch_um__)
53 &raid6_sse2x1,
54 &raid6_sse2x2,
55 &raid6_sse2x4,
56#endif
57#ifdef CONFIG_ALTIVEC
58 &raid6_altivec1,
59 &raid6_altivec2,
60 &raid6_altivec4,
61 &raid6_altivec8,
62#endif
63 NULL
64};
65
66#ifdef __KERNEL__
67#define RAID6_TIME_JIFFIES_LG2 4
68#else
69/* Need more time to be stable in userspace */
70#define RAID6_TIME_JIFFIES_LG2 9
71#define time_before(x, y) ((x) < (y))
72#endif
73
74/* Try to pick the best algorithm */
75/* This code uses the gfmul table as convenient data set to abuse */
76
77int __init raid6_select_algo(void)
78{
79 const struct raid6_calls * const * algo;
80 const struct raid6_calls * best;
81 char *syndromes;
82 void *dptrs[(65536/PAGE_SIZE)+2];
83 int i, disks;
84 unsigned long perf, bestperf;
85 int bestprefer;
86 unsigned long j0, j1;
87
88 disks = (65536/PAGE_SIZE)+2;
89 for ( i = 0 ; i < disks-2 ; i++ ) {
90 dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i;
91 }
92
93 /* Normal code - use a 2-page allocation to avoid D$ conflict */
94 syndromes = (void *) __get_free_pages(GFP_KERNEL, 1);
95
96 if ( !syndromes ) {
97 printk("raid6: Yikes! No memory available.\n");
98 return -ENOMEM;
99 }
100
101 dptrs[disks-2] = syndromes;
102 dptrs[disks-1] = syndromes + PAGE_SIZE;
103
104 bestperf = 0; bestprefer = 0; best = NULL;
105
106 for ( algo = raid6_algos ; *algo ; algo++ ) {
107 if ( !(*algo)->valid || (*algo)->valid() ) {
108 perf = 0;
109
110 preempt_disable();
111 j0 = jiffies;
112 while ( (j1 = jiffies) == j0 )
113 cpu_relax();
114 while (time_before(jiffies,
115 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
116 (*algo)->gen_syndrome(disks, PAGE_SIZE, dptrs);
117 perf++;
118 }
119 preempt_enable();
120
121 if ( (*algo)->prefer > bestprefer ||
122 ((*algo)->prefer == bestprefer &&
123 perf > bestperf) ) {
124 best = *algo;
125 bestprefer = best->prefer;
126 bestperf = perf;
127 }
128 printk("raid6: %-8s %5ld MB/s\n", (*algo)->name,
129 (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
130 }
131 }
132
133 if (best) {
134 printk("raid6: using algorithm %s (%ld MB/s)\n",
135 best->name,
136 (bestperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
137 raid6_call = *best;
138 } else
139 printk("raid6: Yikes! No algorithm found!\n");
140
141 free_pages((unsigned long)syndromes, 1);
142
143 return best ? 0 : -EINVAL;
144}
145
146static void raid6_exit(void)
147{
148 do { } while (0);
149}
150
151subsys_initcall(raid6_select_algo);
152module_exit(raid6_exit);
153MODULE_LICENSE("GPL");
154MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");