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