Loading...
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#if !RAID6_USE_EMPTY_ZERO_PAGE
22/* In .bss so it's zeroed */
23const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
24EXPORT_SYMBOL(raid6_empty_zero_page);
25#endif
26#endif
27
28struct raid6_calls raid6_call;
29EXPORT_SYMBOL_GPL(raid6_call);
30
31const struct raid6_calls * const raid6_algos[] = {
32#if defined(__i386__) && !defined(__arch_um__)
33#ifdef CONFIG_AS_AVX512
34 &raid6_avx512x2,
35 &raid6_avx512x1,
36#endif
37 &raid6_avx2x2,
38 &raid6_avx2x1,
39 &raid6_sse2x2,
40 &raid6_sse2x1,
41 &raid6_sse1x2,
42 &raid6_sse1x1,
43 &raid6_mmxx2,
44 &raid6_mmxx1,
45#endif
46#if defined(__x86_64__) && !defined(__arch_um__)
47#ifdef CONFIG_AS_AVX512
48 &raid6_avx512x4,
49 &raid6_avx512x2,
50 &raid6_avx512x1,
51#endif
52 &raid6_avx2x4,
53 &raid6_avx2x2,
54 &raid6_avx2x1,
55 &raid6_sse2x4,
56 &raid6_sse2x2,
57 &raid6_sse2x1,
58#endif
59#ifdef CONFIG_ALTIVEC
60 &raid6_vpermxor8,
61 &raid6_vpermxor4,
62 &raid6_vpermxor2,
63 &raid6_vpermxor1,
64 &raid6_altivec8,
65 &raid6_altivec4,
66 &raid6_altivec2,
67 &raid6_altivec1,
68#endif
69#if defined(CONFIG_S390)
70 &raid6_s390vx8,
71#endif
72#ifdef CONFIG_KERNEL_MODE_NEON
73 &raid6_neonx8,
74 &raid6_neonx4,
75 &raid6_neonx2,
76 &raid6_neonx1,
77#endif
78#if defined(__ia64__)
79 &raid6_intx32,
80 &raid6_intx16,
81#endif
82 &raid6_intx8,
83 &raid6_intx4,
84 &raid6_intx2,
85 &raid6_intx1,
86 NULL
87};
88
89void (*raid6_2data_recov)(int, size_t, int, int, void **);
90EXPORT_SYMBOL_GPL(raid6_2data_recov);
91
92void (*raid6_datap_recov)(int, size_t, int, void **);
93EXPORT_SYMBOL_GPL(raid6_datap_recov);
94
95const struct raid6_recov_calls *const raid6_recov_algos[] = {
96#ifdef CONFIG_X86
97#ifdef CONFIG_AS_AVX512
98 &raid6_recov_avx512,
99#endif
100 &raid6_recov_avx2,
101 &raid6_recov_ssse3,
102#endif
103#ifdef CONFIG_S390
104 &raid6_recov_s390xc,
105#endif
106#if defined(CONFIG_KERNEL_MODE_NEON)
107 &raid6_recov_neon,
108#endif
109 &raid6_recov_intx1,
110 NULL
111};
112
113#ifdef __KERNEL__
114#define RAID6_TIME_JIFFIES_LG2 4
115#else
116/* Need more time to be stable in userspace */
117#define RAID6_TIME_JIFFIES_LG2 9
118#define time_before(x, y) ((x) < (y))
119#endif
120
121#define RAID6_TEST_DISKS 8
122#define RAID6_TEST_DISKS_ORDER 3
123
124static inline const struct raid6_recov_calls *raid6_choose_recov(void)
125{
126 const struct raid6_recov_calls *const *algo;
127 const struct raid6_recov_calls *best;
128
129 for (best = NULL, algo = raid6_recov_algos; *algo; algo++)
130 if (!best || (*algo)->priority > best->priority)
131 if (!(*algo)->valid || (*algo)->valid())
132 best = *algo;
133
134 if (best) {
135 raid6_2data_recov = best->data2;
136 raid6_datap_recov = best->datap;
137
138 pr_info("raid6: using %s recovery algorithm\n", best->name);
139 } else
140 pr_err("raid6: Yikes! No recovery algorithm found!\n");
141
142 return best;
143}
144
145static inline const struct raid6_calls *raid6_choose_gen(
146 void *(*const dptrs)[RAID6_TEST_DISKS], const int disks)
147{
148 unsigned long perf, bestgenperf, bestxorperf, j0, j1;
149 int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */
150 const struct raid6_calls *const *algo;
151 const struct raid6_calls *best;
152
153 for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) {
154 if (!best || (*algo)->prefer >= best->prefer) {
155 if ((*algo)->valid && !(*algo)->valid())
156 continue;
157
158 if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
159 best = *algo;
160 break;
161 }
162
163 perf = 0;
164
165 preempt_disable();
166 j0 = jiffies;
167 while ((j1 = jiffies) == j0)
168 cpu_relax();
169 while (time_before(jiffies,
170 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
171 (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs);
172 perf++;
173 }
174 preempt_enable();
175
176 if (perf > bestgenperf) {
177 bestgenperf = perf;
178 best = *algo;
179 }
180 pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name,
181 (perf * HZ * (disks-2)) >>
182 (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2));
183
184 if (!(*algo)->xor_syndrome)
185 continue;
186
187 perf = 0;
188
189 preempt_disable();
190 j0 = jiffies;
191 while ((j1 = jiffies) == j0)
192 cpu_relax();
193 while (time_before(jiffies,
194 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
195 (*algo)->xor_syndrome(disks, start, stop,
196 PAGE_SIZE, *dptrs);
197 perf++;
198 }
199 preempt_enable();
200
201 if (best == *algo)
202 bestxorperf = perf;
203
204 pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name,
205 (perf * HZ * (disks-2)) >>
206 (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1));
207 }
208 }
209
210 if (best) {
211 if (IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
212 pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
213 best->name,
214 (bestgenperf * HZ * (disks-2)) >>
215 (20 - PAGE_SHIFT+RAID6_TIME_JIFFIES_LG2));
216 if (best->xor_syndrome)
217 pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
218 (bestxorperf * HZ * (disks-2)) >>
219 (20 - PAGE_SHIFT + RAID6_TIME_JIFFIES_LG2 + 1));
220 } else
221 pr_info("raid6: skip pq benchmark and using algorithm %s\n",
222 best->name);
223 raid6_call = *best;
224 } else
225 pr_err("raid6: Yikes! No algorithm found!\n");
226
227 return best;
228}
229
230
231/* Try to pick the best algorithm */
232/* This code uses the gfmul table as convenient data set to abuse */
233
234int __init raid6_select_algo(void)
235{
236 const int disks = RAID6_TEST_DISKS;
237
238 const struct raid6_calls *gen_best;
239 const struct raid6_recov_calls *rec_best;
240 char *disk_ptr, *p;
241 void *dptrs[RAID6_TEST_DISKS];
242 int i, cycle;
243
244 /* prepare the buffer and fill it circularly with gfmul table */
245 disk_ptr = (char *)__get_free_pages(GFP_KERNEL, RAID6_TEST_DISKS_ORDER);
246 if (!disk_ptr) {
247 pr_err("raid6: Yikes! No memory available.\n");
248 return -ENOMEM;
249 }
250
251 p = disk_ptr;
252 for (i = 0; i < disks; i++)
253 dptrs[i] = p + PAGE_SIZE * i;
254
255 cycle = ((disks - 2) * PAGE_SIZE) / 65536;
256 for (i = 0; i < cycle; i++) {
257 memcpy(p, raid6_gfmul, 65536);
258 p += 65536;
259 }
260
261 if ((disks - 2) * PAGE_SIZE % 65536)
262 memcpy(p, raid6_gfmul, (disks - 2) * PAGE_SIZE % 65536);
263
264 /* select raid gen_syndrome function */
265 gen_best = raid6_choose_gen(&dptrs, disks);
266
267 /* select raid recover functions */
268 rec_best = raid6_choose_recov();
269
270 free_pages((unsigned long)disk_ptr, RAID6_TEST_DISKS_ORDER);
271
272 return gen_best && rec_best ? 0 : -EINVAL;
273}
274
275static void raid6_exit(void)
276{
277 do { } while (0);
278}
279
280subsys_initcall(raid6_select_algo);
281module_exit(raid6_exit);
282MODULE_LICENSE("GPL");
283MODULE_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");