Loading...
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// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- linux-c -*- ------------------------------------------------------- *
3 *
4 * Copyright 2002 H. Peter Anvin - All Rights Reserved
5 *
6 * ----------------------------------------------------------------------- */
7
8/*
9 * raid6/algos.c
10 *
11 * Algorithm list and algorithm selection for RAID-6
12 */
13
14#include <linux/raid/pq.h>
15#ifndef __KERNEL__
16#include <sys/mman.h>
17#include <stdio.h>
18#else
19#include <linux/module.h>
20#include <linux/gfp.h>
21/* In .bss so it's zeroed */
22const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
23EXPORT_SYMBOL(raid6_empty_zero_page);
24#endif
25
26struct raid6_calls raid6_call;
27EXPORT_SYMBOL_GPL(raid6_call);
28
29const struct raid6_calls * const raid6_algos[] = {
30#if defined(__i386__) && !defined(__arch_um__)
31#ifdef CONFIG_AS_AVX512
32 &raid6_avx512x2,
33 &raid6_avx512x1,
34#endif
35 &raid6_avx2x2,
36 &raid6_avx2x1,
37 &raid6_sse2x2,
38 &raid6_sse2x1,
39 &raid6_sse1x2,
40 &raid6_sse1x1,
41 &raid6_mmxx2,
42 &raid6_mmxx1,
43#endif
44#if defined(__x86_64__) && !defined(__arch_um__)
45#ifdef CONFIG_AS_AVX512
46 &raid6_avx512x4,
47 &raid6_avx512x2,
48 &raid6_avx512x1,
49#endif
50 &raid6_avx2x4,
51 &raid6_avx2x2,
52 &raid6_avx2x1,
53 &raid6_sse2x4,
54 &raid6_sse2x2,
55 &raid6_sse2x1,
56#endif
57#ifdef CONFIG_ALTIVEC
58 &raid6_vpermxor8,
59 &raid6_vpermxor4,
60 &raid6_vpermxor2,
61 &raid6_vpermxor1,
62 &raid6_altivec8,
63 &raid6_altivec4,
64 &raid6_altivec2,
65 &raid6_altivec1,
66#endif
67#if defined(CONFIG_S390)
68 &raid6_s390vx8,
69#endif
70#ifdef CONFIG_KERNEL_MODE_NEON
71 &raid6_neonx8,
72 &raid6_neonx4,
73 &raid6_neonx2,
74 &raid6_neonx1,
75#endif
76#ifdef CONFIG_LOONGARCH
77#ifdef CONFIG_CPU_HAS_LASX
78 &raid6_lasx,
79#endif
80#ifdef CONFIG_CPU_HAS_LSX
81 &raid6_lsx,
82#endif
83#endif
84 &raid6_intx8,
85 &raid6_intx4,
86 &raid6_intx2,
87 &raid6_intx1,
88 NULL
89};
90
91void (*raid6_2data_recov)(int, size_t, int, int, void **);
92EXPORT_SYMBOL_GPL(raid6_2data_recov);
93
94void (*raid6_datap_recov)(int, size_t, int, void **);
95EXPORT_SYMBOL_GPL(raid6_datap_recov);
96
97const struct raid6_recov_calls *const raid6_recov_algos[] = {
98#ifdef CONFIG_X86
99#ifdef CONFIG_AS_AVX512
100 &raid6_recov_avx512,
101#endif
102 &raid6_recov_avx2,
103 &raid6_recov_ssse3,
104#endif
105#ifdef CONFIG_S390
106 &raid6_recov_s390xc,
107#endif
108#if defined(CONFIG_KERNEL_MODE_NEON)
109 &raid6_recov_neon,
110#endif
111#ifdef CONFIG_LOONGARCH
112#ifdef CONFIG_CPU_HAS_LASX
113 &raid6_recov_lasx,
114#endif
115#ifdef CONFIG_CPU_HAS_LSX
116 &raid6_recov_lsx,
117#endif
118#endif
119 &raid6_recov_intx1,
120 NULL
121};
122
123#ifdef __KERNEL__
124#define RAID6_TIME_JIFFIES_LG2 4
125#else
126/* Need more time to be stable in userspace */
127#define RAID6_TIME_JIFFIES_LG2 9
128#define time_before(x, y) ((x) < (y))
129#endif
130
131#define RAID6_TEST_DISKS 8
132#define RAID6_TEST_DISKS_ORDER 3
133
134static inline const struct raid6_recov_calls *raid6_choose_recov(void)
135{
136 const struct raid6_recov_calls *const *algo;
137 const struct raid6_recov_calls *best;
138
139 for (best = NULL, algo = raid6_recov_algos; *algo; algo++)
140 if (!best || (*algo)->priority > best->priority)
141 if (!(*algo)->valid || (*algo)->valid())
142 best = *algo;
143
144 if (best) {
145 raid6_2data_recov = best->data2;
146 raid6_datap_recov = best->datap;
147
148 pr_info("raid6: using %s recovery algorithm\n", best->name);
149 } else
150 pr_err("raid6: Yikes! No recovery algorithm found!\n");
151
152 return best;
153}
154
155static inline const struct raid6_calls *raid6_choose_gen(
156 void *(*const dptrs)[RAID6_TEST_DISKS], const int disks)
157{
158 unsigned long perf, bestgenperf, j0, j1;
159 int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */
160 const struct raid6_calls *const *algo;
161 const struct raid6_calls *best;
162
163 for (bestgenperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) {
164 if (!best || (*algo)->priority >= best->priority) {
165 if ((*algo)->valid && !(*algo)->valid())
166 continue;
167
168 if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
169 best = *algo;
170 break;
171 }
172
173 perf = 0;
174
175 preempt_disable();
176 j0 = jiffies;
177 while ((j1 = jiffies) == j0)
178 cpu_relax();
179 while (time_before(jiffies,
180 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
181 (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs);
182 perf++;
183 }
184 preempt_enable();
185
186 if (perf > bestgenperf) {
187 bestgenperf = perf;
188 best = *algo;
189 }
190 pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name,
191 (perf * HZ * (disks-2)) >>
192 (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2));
193 }
194 }
195
196 if (!best) {
197 pr_err("raid6: Yikes! No algorithm found!\n");
198 goto out;
199 }
200
201 raid6_call = *best;
202
203 if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
204 pr_info("raid6: skipped pq benchmark and selected %s\n",
205 best->name);
206 goto out;
207 }
208
209 pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
210 best->name,
211 (bestgenperf * HZ * (disks - 2)) >>
212 (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2));
213
214 if (best->xor_syndrome) {
215 perf = 0;
216
217 preempt_disable();
218 j0 = jiffies;
219 while ((j1 = jiffies) == j0)
220 cpu_relax();
221 while (time_before(jiffies,
222 j1 + (1 << RAID6_TIME_JIFFIES_LG2))) {
223 best->xor_syndrome(disks, start, stop,
224 PAGE_SIZE, *dptrs);
225 perf++;
226 }
227 preempt_enable();
228
229 pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
230 (perf * HZ * (disks - 2)) >>
231 (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1));
232 }
233
234out:
235 return best;
236}
237
238
239/* Try to pick the best algorithm */
240/* This code uses the gfmul table as convenient data set to abuse */
241
242int __init raid6_select_algo(void)
243{
244 const int disks = RAID6_TEST_DISKS;
245
246 const struct raid6_calls *gen_best;
247 const struct raid6_recov_calls *rec_best;
248 char *disk_ptr, *p;
249 void *dptrs[RAID6_TEST_DISKS];
250 int i, cycle;
251
252 /* prepare the buffer and fill it circularly with gfmul table */
253 disk_ptr = (char *)__get_free_pages(GFP_KERNEL, RAID6_TEST_DISKS_ORDER);
254 if (!disk_ptr) {
255 pr_err("raid6: Yikes! No memory available.\n");
256 return -ENOMEM;
257 }
258
259 p = disk_ptr;
260 for (i = 0; i < disks; i++)
261 dptrs[i] = p + PAGE_SIZE * i;
262
263 cycle = ((disks - 2) * PAGE_SIZE) / 65536;
264 for (i = 0; i < cycle; i++) {
265 memcpy(p, raid6_gfmul, 65536);
266 p += 65536;
267 }
268
269 if ((disks - 2) * PAGE_SIZE % 65536)
270 memcpy(p, raid6_gfmul, (disks - 2) * PAGE_SIZE % 65536);
271
272 /* select raid gen_syndrome function */
273 gen_best = raid6_choose_gen(&dptrs, disks);
274
275 /* select raid recover functions */
276 rec_best = raid6_choose_recov();
277
278 free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER);
279
280 return gen_best && rec_best ? 0 : -EINVAL;
281}
282
283static void raid6_exit(void)
284{
285 do { } while (0);
286}
287
288subsys_initcall(raid6_select_algo);
289module_exit(raid6_exit);
290MODULE_LICENSE("GPL");
291MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");