This source file includes following definitions.
- raid6_choose_recov
- raid6_choose_gen
- raid6_select_algo
- raid6_exit
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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
23 const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
24 EXPORT_SYMBOL(raid6_empty_zero_page);
25 #endif
26 #endif
27
28 struct raid6_calls raid6_call;
29 EXPORT_SYMBOL_GPL(raid6_call);
30
31 const 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 #ifdef CONFIG_AS_AVX2
38 &raid6_avx2x2,
39 &raid6_avx2x1,
40 #endif
41 &raid6_sse2x2,
42 &raid6_sse2x1,
43 &raid6_sse1x2,
44 &raid6_sse1x1,
45 &raid6_mmxx2,
46 &raid6_mmxx1,
47 #endif
48 #if defined(__x86_64__) && !defined(__arch_um__)
49 #ifdef CONFIG_AS_AVX512
50 &raid6_avx512x4,
51 &raid6_avx512x2,
52 &raid6_avx512x1,
53 #endif
54 #ifdef CONFIG_AS_AVX2
55 &raid6_avx2x4,
56 &raid6_avx2x2,
57 &raid6_avx2x1,
58 #endif
59 &raid6_sse2x4,
60 &raid6_sse2x2,
61 &raid6_sse2x1,
62 #endif
63 #ifdef CONFIG_ALTIVEC
64 &raid6_vpermxor8,
65 &raid6_vpermxor4,
66 &raid6_vpermxor2,
67 &raid6_vpermxor1,
68 &raid6_altivec8,
69 &raid6_altivec4,
70 &raid6_altivec2,
71 &raid6_altivec1,
72 #endif
73 #if defined(CONFIG_S390)
74 &raid6_s390vx8,
75 #endif
76 #ifdef CONFIG_KERNEL_MODE_NEON
77 &raid6_neonx8,
78 &raid6_neonx4,
79 &raid6_neonx2,
80 &raid6_neonx1,
81 #endif
82 #if defined(__ia64__)
83 &raid6_intx32,
84 &raid6_intx16,
85 #endif
86 &raid6_intx8,
87 &raid6_intx4,
88 &raid6_intx2,
89 &raid6_intx1,
90 NULL
91 };
92
93 void (*raid6_2data_recov)(int, size_t, int, int, void **);
94 EXPORT_SYMBOL_GPL(raid6_2data_recov);
95
96 void (*raid6_datap_recov)(int, size_t, int, void **);
97 EXPORT_SYMBOL_GPL(raid6_datap_recov);
98
99 const struct raid6_recov_calls *const raid6_recov_algos[] = {
100 #ifdef CONFIG_AS_AVX512
101 &raid6_recov_avx512,
102 #endif
103 #ifdef CONFIG_AS_AVX2
104 &raid6_recov_avx2,
105 #endif
106 #ifdef CONFIG_AS_SSSE3
107 &raid6_recov_ssse3,
108 #endif
109 #ifdef CONFIG_S390
110 &raid6_recov_s390xc,
111 #endif
112 #if defined(CONFIG_KERNEL_MODE_NEON)
113 &raid6_recov_neon,
114 #endif
115 &raid6_recov_intx1,
116 NULL
117 };
118
119 #ifdef __KERNEL__
120 #define RAID6_TIME_JIFFIES_LG2 4
121 #else
122
123 #define RAID6_TIME_JIFFIES_LG2 9
124 #define time_before(x, y) ((x) < (y))
125 #endif
126
127 static inline const struct raid6_recov_calls *raid6_choose_recov(void)
128 {
129 const struct raid6_recov_calls *const *algo;
130 const struct raid6_recov_calls *best;
131
132 for (best = NULL, algo = raid6_recov_algos; *algo; algo++)
133 if (!best || (*algo)->priority > best->priority)
134 if (!(*algo)->valid || (*algo)->valid())
135 best = *algo;
136
137 if (best) {
138 raid6_2data_recov = best->data2;
139 raid6_datap_recov = best->datap;
140
141 pr_info("raid6: using %s recovery algorithm\n", best->name);
142 } else
143 pr_err("raid6: Yikes! No recovery algorithm found!\n");
144
145 return best;
146 }
147
148 static inline const struct raid6_calls *raid6_choose_gen(
149 void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks)
150 {
151 unsigned long perf, bestgenperf, bestxorperf, j0, j1;
152 int start = (disks>>1)-1, stop = disks-3;
153 const struct raid6_calls *const *algo;
154 const struct raid6_calls *best;
155
156 for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) {
157 if (!best || (*algo)->prefer >= best->prefer) {
158 if ((*algo)->valid && !(*algo)->valid())
159 continue;
160
161 if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
162 best = *algo;
163 break;
164 }
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
227
228
229 int __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
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
254 gen_best = raid6_choose_gen(&dptrs, disks);
255
256
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
264 static void raid6_exit(void)
265 {
266 do { } while (0);
267 }
268
269 subsys_initcall(raid6_select_algo);
270 module_exit(raid6_exit);
271 MODULE_LICENSE("GPL");
272 MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");