1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
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
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#endif
53#if defined(__x86_64__) && !defined(__arch_um__)
54 &raid6_sse2x1,
55 &raid6_sse2x2,
56 &raid6_sse2x4,
57#ifdef CONFIG_AS_AVX2
58 &raid6_avx2x1,
59 &raid6_avx2x2,
60 &raid6_avx2x4,
61#endif
62#endif
63#ifdef CONFIG_ALTIVEC
64 &raid6_altivec1,
65 &raid6_altivec2,
66 &raid6_altivec4,
67 &raid6_altivec8,
68#endif
69#if defined(CONFIG_TILEGX)
70 &raid6_tilegx8,
71#endif
72 &raid6_intx1,
73 &raid6_intx2,
74 &raid6_intx4,
75 &raid6_intx8,
76#ifdef CONFIG_KERNEL_MODE_NEON
77 &raid6_neonx1,
78 &raid6_neonx2,
79 &raid6_neonx4,
80 &raid6_neonx8,
81#endif
82 NULL
83};
84
85void (*raid6_2data_recov)(int, size_t, int, int, void **);
86EXPORT_SYMBOL_GPL(raid6_2data_recov);
87
88void (*raid6_datap_recov)(int, size_t, int, void **);
89EXPORT_SYMBOL_GPL(raid6_datap_recov);
90
91const struct raid6_recov_calls *const raid6_recov_algos[] = {
92#ifdef CONFIG_AS_AVX2
93 &raid6_recov_avx2,
94#endif
95#ifdef CONFIG_AS_SSSE3
96 &raid6_recov_ssse3,
97#endif
98 &raid6_recov_intx1,
99 NULL
100};
101
102#ifdef __KERNEL__
103#define RAID6_TIME_JIFFIES_LG2 4
104#else
105
106#define RAID6_TIME_JIFFIES_LG2 9
107#define time_before(x, y) ((x) < (y))
108#endif
109
110static inline const struct raid6_recov_calls *raid6_choose_recov(void)
111{
112 const struct raid6_recov_calls *const *algo;
113 const struct raid6_recov_calls *best;
114
115 for (best = NULL, algo = raid6_recov_algos; *algo; algo++)
116 if (!best || (*algo)->priority > best->priority)
117 if (!(*algo)->valid || (*algo)->valid())
118 best = *algo;
119
120 if (best) {
121 raid6_2data_recov = best->data2;
122 raid6_datap_recov = best->datap;
123
124 pr_info("raid6: using %s recovery algorithm\n", best->name);
125 } else
126 pr_err("raid6: Yikes! No recovery algorithm found!\n");
127
128 return best;
129}
130
131static inline const struct raid6_calls *raid6_choose_gen(
132 void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks)
133{
134 unsigned long perf, bestgenperf, bestxorperf, j0, j1;
135 int start = (disks>>1)-1, stop = disks-3;
136 const struct raid6_calls *const *algo;
137 const struct raid6_calls *best;
138
139 for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) {
140 if (!best || (*algo)->prefer >= best->prefer) {
141 if ((*algo)->valid && !(*algo)->valid())
142 continue;
143
144 perf = 0;
145
146 preempt_disable();
147 j0 = jiffies;
148 while ((j1 = jiffies) == j0)
149 cpu_relax();
150 while (time_before(jiffies,
151 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
152 (*algo)->gen_syndrome(disks, PAGE_SIZE, *dptrs);
153 perf++;
154 }
155 preempt_enable();
156
157 if (perf > bestgenperf) {
158 bestgenperf = perf;
159 best = *algo;
160 }
161 pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name,
162 (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
163
164 if (!(*algo)->xor_syndrome)
165 continue;
166
167 perf = 0;
168
169 preempt_disable();
170 j0 = jiffies;
171 while ((j1 = jiffies) == j0)
172 cpu_relax();
173 while (time_before(jiffies,
174 j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
175 (*algo)->xor_syndrome(disks, start, stop,
176 PAGE_SIZE, *dptrs);
177 perf++;
178 }
179 preempt_enable();
180
181 if (best == *algo)
182 bestxorperf = perf;
183
184 pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name,
185 (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1));
186 }
187 }
188
189 if (best) {
190 pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
191 best->name,
192 (bestgenperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
193 if (best->xor_syndrome)
194 pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
195 (bestxorperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1));
196 raid6_call = *best;
197 } else
198 pr_err("raid6: Yikes! No algorithm found!\n");
199
200 return best;
201}
202
203
204
205
206
207int __init raid6_select_algo(void)
208{
209 const int disks = (65536/PAGE_SIZE)+2;
210
211 const struct raid6_calls *gen_best;
212 const struct raid6_recov_calls *rec_best;
213 char *syndromes;
214 void *dptrs[(65536/PAGE_SIZE)+2];
215 int i;
216
217 for (i = 0; i < disks-2; i++)
218 dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i;
219
220
221 syndromes = (void *) __get_free_pages(GFP_KERNEL, 1);
222
223 if (!syndromes) {
224 pr_err("raid6: Yikes! No memory available.\n");
225 return -ENOMEM;
226 }
227
228 dptrs[disks-2] = syndromes;
229 dptrs[disks-1] = syndromes + PAGE_SIZE;
230
231
232 gen_best = raid6_choose_gen(&dptrs, disks);
233
234
235 rec_best = raid6_choose_recov();
236
237 free_pages((unsigned long)syndromes, 1);
238
239 return gen_best && rec_best ? 0 : -EINVAL;
240}
241
242static void raid6_exit(void)
243{
244 do { } while (0);
245}
246
247subsys_initcall(raid6_select_algo);
248module_exit(raid6_exit);
249MODULE_LICENSE("GPL");
250MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");
251
