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0a82a623 DW |
1 | /* |
2 | * Asynchronous RAID-6 recovery calculations ASYNC_TX API. | |
3 | * Copyright(c) 2009 Intel Corporation | |
4 | * | |
5 | * based on raid6recov.c: | |
6 | * Copyright 2002 H. Peter Anvin | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2 of the License, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
16 | * more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License along with | |
19 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
20 | * Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | |
21 | * | |
22 | */ | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/interrupt.h> | |
4bb33cc8 | 25 | #include <linux/module.h> |
0a82a623 DW |
26 | #include <linux/dma-mapping.h> |
27 | #include <linux/raid/pq.h> | |
28 | #include <linux/async_tx.h> | |
29 | ||
30 | static struct dma_async_tx_descriptor * | |
31 | async_sum_product(struct page *dest, struct page **srcs, unsigned char *coef, | |
32 | size_t len, struct async_submit_ctl *submit) | |
33 | { | |
34 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ, | |
35 | &dest, 1, srcs, 2, len); | |
36 | struct dma_device *dma = chan ? chan->device : NULL; | |
37 | const u8 *amul, *bmul; | |
38 | u8 ax, bx; | |
39 | u8 *a, *b, *c; | |
40 | ||
41 | if (dma) { | |
42 | dma_addr_t dma_dest[2]; | |
43 | dma_addr_t dma_src[2]; | |
44 | struct device *dev = dma->dev; | |
45 | struct dma_async_tx_descriptor *tx; | |
46 | enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P; | |
47 | ||
0403e382 DW |
48 | if (submit->flags & ASYNC_TX_FENCE) |
49 | dma_flags |= DMA_PREP_FENCE; | |
0a82a623 DW |
50 | dma_dest[1] = dma_map_page(dev, dest, 0, len, DMA_BIDIRECTIONAL); |
51 | dma_src[0] = dma_map_page(dev, srcs[0], 0, len, DMA_TO_DEVICE); | |
52 | dma_src[1] = dma_map_page(dev, srcs[1], 0, len, DMA_TO_DEVICE); | |
53 | tx = dma->device_prep_dma_pq(chan, dma_dest, dma_src, 2, coef, | |
54 | len, dma_flags); | |
55 | if (tx) { | |
56 | async_tx_submit(chan, tx, submit); | |
57 | return tx; | |
58 | } | |
1f6672d4 DW |
59 | |
60 | /* could not get a descriptor, unmap and fall through to | |
61 | * the synchronous path | |
62 | */ | |
63 | dma_unmap_page(dev, dma_dest[1], len, DMA_BIDIRECTIONAL); | |
64 | dma_unmap_page(dev, dma_src[0], len, DMA_TO_DEVICE); | |
65 | dma_unmap_page(dev, dma_src[1], len, DMA_TO_DEVICE); | |
0a82a623 DW |
66 | } |
67 | ||
68 | /* run the operation synchronously */ | |
69 | async_tx_quiesce(&submit->depend_tx); | |
70 | amul = raid6_gfmul[coef[0]]; | |
71 | bmul = raid6_gfmul[coef[1]]; | |
72 | a = page_address(srcs[0]); | |
73 | b = page_address(srcs[1]); | |
74 | c = page_address(dest); | |
75 | ||
76 | while (len--) { | |
77 | ax = amul[*a++]; | |
78 | bx = bmul[*b++]; | |
79 | *c++ = ax ^ bx; | |
80 | } | |
81 | ||
82 | return NULL; | |
83 | } | |
84 | ||
85 | static struct dma_async_tx_descriptor * | |
86 | async_mult(struct page *dest, struct page *src, u8 coef, size_t len, | |
87 | struct async_submit_ctl *submit) | |
88 | { | |
89 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ, | |
90 | &dest, 1, &src, 1, len); | |
91 | struct dma_device *dma = chan ? chan->device : NULL; | |
92 | const u8 *qmul; /* Q multiplier table */ | |
93 | u8 *d, *s; | |
94 | ||
95 | if (dma) { | |
96 | dma_addr_t dma_dest[2]; | |
97 | dma_addr_t dma_src[1]; | |
98 | struct device *dev = dma->dev; | |
99 | struct dma_async_tx_descriptor *tx; | |
100 | enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P; | |
101 | ||
0403e382 DW |
102 | if (submit->flags & ASYNC_TX_FENCE) |
103 | dma_flags |= DMA_PREP_FENCE; | |
0a82a623 DW |
104 | dma_dest[1] = dma_map_page(dev, dest, 0, len, DMA_BIDIRECTIONAL); |
105 | dma_src[0] = dma_map_page(dev, src, 0, len, DMA_TO_DEVICE); | |
106 | tx = dma->device_prep_dma_pq(chan, dma_dest, dma_src, 1, &coef, | |
107 | len, dma_flags); | |
108 | if (tx) { | |
109 | async_tx_submit(chan, tx, submit); | |
110 | return tx; | |
111 | } | |
1f6672d4 DW |
112 | |
113 | /* could not get a descriptor, unmap and fall through to | |
114 | * the synchronous path | |
115 | */ | |
116 | dma_unmap_page(dev, dma_dest[1], len, DMA_BIDIRECTIONAL); | |
117 | dma_unmap_page(dev, dma_src[0], len, DMA_TO_DEVICE); | |
0a82a623 DW |
118 | } |
119 | ||
120 | /* no channel available, or failed to allocate a descriptor, so | |
121 | * perform the operation synchronously | |
122 | */ | |
123 | async_tx_quiesce(&submit->depend_tx); | |
124 | qmul = raid6_gfmul[coef]; | |
125 | d = page_address(dest); | |
126 | s = page_address(src); | |
127 | ||
128 | while (len--) | |
129 | *d++ = qmul[*s++]; | |
130 | ||
131 | return NULL; | |
132 | } | |
133 | ||
134 | static struct dma_async_tx_descriptor * | |
da17bf43 DW |
135 | __2data_recov_4(int disks, size_t bytes, int faila, int failb, |
136 | struct page **blocks, struct async_submit_ctl *submit) | |
0a82a623 DW |
137 | { |
138 | struct dma_async_tx_descriptor *tx = NULL; | |
139 | struct page *p, *q, *a, *b; | |
140 | struct page *srcs[2]; | |
141 | unsigned char coef[2]; | |
142 | enum async_tx_flags flags = submit->flags; | |
143 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
144 | void *cb_param = submit->cb_param; | |
145 | void *scribble = submit->scribble; | |
146 | ||
da17bf43 DW |
147 | p = blocks[disks-2]; |
148 | q = blocks[disks-1]; | |
0a82a623 DW |
149 | |
150 | a = blocks[faila]; | |
151 | b = blocks[failb]; | |
152 | ||
153 | /* in the 4 disk case P + Pxy == P and Q + Qxy == Q */ | |
154 | /* Dx = A*(P+Pxy) + B*(Q+Qxy) */ | |
155 | srcs[0] = p; | |
156 | srcs[1] = q; | |
157 | coef[0] = raid6_gfexi[failb-faila]; | |
158 | coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]; | |
0403e382 | 159 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
160 | tx = async_sum_product(b, srcs, coef, bytes, submit); |
161 | ||
162 | /* Dy = P+Pxy+Dx */ | |
163 | srcs[0] = p; | |
164 | srcs[1] = b; | |
165 | init_async_submit(submit, flags | ASYNC_TX_XOR_ZERO_DST, tx, cb_fn, | |
166 | cb_param, scribble); | |
167 | tx = async_xor(a, srcs, 0, 2, bytes, submit); | |
168 | ||
169 | return tx; | |
170 | ||
171 | } | |
172 | ||
173 | static struct dma_async_tx_descriptor * | |
da17bf43 DW |
174 | __2data_recov_5(int disks, size_t bytes, int faila, int failb, |
175 | struct page **blocks, struct async_submit_ctl *submit) | |
0a82a623 DW |
176 | { |
177 | struct dma_async_tx_descriptor *tx = NULL; | |
178 | struct page *p, *q, *g, *dp, *dq; | |
179 | struct page *srcs[2]; | |
180 | unsigned char coef[2]; | |
181 | enum async_tx_flags flags = submit->flags; | |
182 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
183 | void *cb_param = submit->cb_param; | |
184 | void *scribble = submit->scribble; | |
da17bf43 | 185 | int good_srcs, good, i; |
0a82a623 | 186 | |
da17bf43 DW |
187 | good_srcs = 0; |
188 | good = -1; | |
189 | for (i = 0; i < disks-2; i++) { | |
190 | if (blocks[i] == NULL) | |
191 | continue; | |
0a82a623 DW |
192 | if (i == faila || i == failb) |
193 | continue; | |
da17bf43 DW |
194 | good = i; |
195 | good_srcs++; | |
0a82a623 | 196 | } |
da17bf43 | 197 | BUG_ON(good_srcs > 1); |
0a82a623 | 198 | |
da17bf43 DW |
199 | p = blocks[disks-2]; |
200 | q = blocks[disks-1]; | |
0a82a623 DW |
201 | g = blocks[good]; |
202 | ||
203 | /* Compute syndrome with zero for the missing data pages | |
204 | * Use the dead data pages as temporary storage for delta p and | |
205 | * delta q | |
206 | */ | |
207 | dp = blocks[faila]; | |
208 | dq = blocks[failb]; | |
209 | ||
0403e382 | 210 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 | 211 | tx = async_memcpy(dp, g, 0, 0, bytes, submit); |
0403e382 | 212 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
213 | tx = async_mult(dq, g, raid6_gfexp[good], bytes, submit); |
214 | ||
215 | /* compute P + Pxy */ | |
216 | srcs[0] = dp; | |
217 | srcs[1] = p; | |
0403e382 DW |
218 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
219 | NULL, NULL, scribble); | |
0a82a623 DW |
220 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); |
221 | ||
222 | /* compute Q + Qxy */ | |
223 | srcs[0] = dq; | |
224 | srcs[1] = q; | |
0403e382 DW |
225 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
226 | NULL, NULL, scribble); | |
0a82a623 DW |
227 | tx = async_xor(dq, srcs, 0, 2, bytes, submit); |
228 | ||
229 | /* Dx = A*(P+Pxy) + B*(Q+Qxy) */ | |
230 | srcs[0] = dp; | |
231 | srcs[1] = dq; | |
232 | coef[0] = raid6_gfexi[failb-faila]; | |
233 | coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]; | |
0403e382 | 234 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
235 | tx = async_sum_product(dq, srcs, coef, bytes, submit); |
236 | ||
237 | /* Dy = P+Pxy+Dx */ | |
238 | srcs[0] = dp; | |
239 | srcs[1] = dq; | |
240 | init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn, | |
241 | cb_param, scribble); | |
242 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); | |
243 | ||
244 | return tx; | |
245 | } | |
246 | ||
247 | static struct dma_async_tx_descriptor * | |
248 | __2data_recov_n(int disks, size_t bytes, int faila, int failb, | |
249 | struct page **blocks, struct async_submit_ctl *submit) | |
250 | { | |
251 | struct dma_async_tx_descriptor *tx = NULL; | |
252 | struct page *p, *q, *dp, *dq; | |
253 | struct page *srcs[2]; | |
254 | unsigned char coef[2]; | |
255 | enum async_tx_flags flags = submit->flags; | |
256 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
257 | void *cb_param = submit->cb_param; | |
258 | void *scribble = submit->scribble; | |
259 | ||
260 | p = blocks[disks-2]; | |
261 | q = blocks[disks-1]; | |
262 | ||
263 | /* Compute syndrome with zero for the missing data pages | |
264 | * Use the dead data pages as temporary storage for | |
265 | * delta p and delta q | |
266 | */ | |
267 | dp = blocks[faila]; | |
5dd33c9a | 268 | blocks[faila] = NULL; |
0a82a623 DW |
269 | blocks[disks-2] = dp; |
270 | dq = blocks[failb]; | |
5dd33c9a | 271 | blocks[failb] = NULL; |
0a82a623 DW |
272 | blocks[disks-1] = dq; |
273 | ||
0403e382 | 274 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
275 | tx = async_gen_syndrome(blocks, 0, disks, bytes, submit); |
276 | ||
277 | /* Restore pointer table */ | |
278 | blocks[faila] = dp; | |
279 | blocks[failb] = dq; | |
280 | blocks[disks-2] = p; | |
281 | blocks[disks-1] = q; | |
282 | ||
283 | /* compute P + Pxy */ | |
284 | srcs[0] = dp; | |
285 | srcs[1] = p; | |
0403e382 DW |
286 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
287 | NULL, NULL, scribble); | |
0a82a623 DW |
288 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); |
289 | ||
290 | /* compute Q + Qxy */ | |
291 | srcs[0] = dq; | |
292 | srcs[1] = q; | |
0403e382 DW |
293 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
294 | NULL, NULL, scribble); | |
0a82a623 DW |
295 | tx = async_xor(dq, srcs, 0, 2, bytes, submit); |
296 | ||
297 | /* Dx = A*(P+Pxy) + B*(Q+Qxy) */ | |
298 | srcs[0] = dp; | |
299 | srcs[1] = dq; | |
300 | coef[0] = raid6_gfexi[failb-faila]; | |
301 | coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]; | |
0403e382 | 302 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
303 | tx = async_sum_product(dq, srcs, coef, bytes, submit); |
304 | ||
305 | /* Dy = P+Pxy+Dx */ | |
306 | srcs[0] = dp; | |
307 | srcs[1] = dq; | |
308 | init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn, | |
309 | cb_param, scribble); | |
310 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); | |
311 | ||
312 | return tx; | |
313 | } | |
314 | ||
315 | /** | |
316 | * async_raid6_2data_recov - asynchronously calculate two missing data blocks | |
317 | * @disks: number of disks in the RAID-6 array | |
318 | * @bytes: block size | |
319 | * @faila: first failed drive index | |
320 | * @failb: second failed drive index | |
321 | * @blocks: array of source pointers where the last two entries are p and q | |
322 | * @submit: submission/completion modifiers | |
323 | */ | |
324 | struct dma_async_tx_descriptor * | |
325 | async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb, | |
326 | struct page **blocks, struct async_submit_ctl *submit) | |
327 | { | |
5157b4aa | 328 | void *scribble = submit->scribble; |
da17bf43 DW |
329 | int non_zero_srcs, i; |
330 | ||
0a82a623 DW |
331 | BUG_ON(faila == failb); |
332 | if (failb < faila) | |
333 | swap(faila, failb); | |
334 | ||
335 | pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes); | |
336 | ||
5157b4aa DW |
337 | /* if a dma resource is not available or a scribble buffer is not |
338 | * available punt to the synchronous path. In the 'dma not | |
339 | * available' case be sure to use the scribble buffer to | |
340 | * preserve the content of 'blocks' as the caller intended. | |
0a82a623 | 341 | */ |
5157b4aa DW |
342 | if (!async_dma_find_channel(DMA_PQ) || !scribble) { |
343 | void **ptrs = scribble ? scribble : (void **) blocks; | |
0a82a623 DW |
344 | |
345 | async_tx_quiesce(&submit->depend_tx); | |
346 | for (i = 0; i < disks; i++) | |
5dd33c9a | 347 | if (blocks[i] == NULL) |
da17bf43 | 348 | ptrs[i] = (void *) raid6_empty_zero_page; |
5dd33c9a N |
349 | else |
350 | ptrs[i] = page_address(blocks[i]); | |
0a82a623 DW |
351 | |
352 | raid6_2data_recov(disks, bytes, faila, failb, ptrs); | |
353 | ||
354 | async_tx_sync_epilog(submit); | |
355 | ||
356 | return NULL; | |
357 | } | |
358 | ||
da17bf43 DW |
359 | non_zero_srcs = 0; |
360 | for (i = 0; i < disks-2 && non_zero_srcs < 4; i++) | |
361 | if (blocks[i]) | |
362 | non_zero_srcs++; | |
363 | switch (non_zero_srcs) { | |
364 | case 0: | |
365 | case 1: | |
366 | /* There must be at least 2 sources - the failed devices. */ | |
367 | BUG(); | |
368 | ||
369 | case 2: | |
0a82a623 DW |
370 | /* dma devices do not uniformly understand a zero source pq |
371 | * operation (in contrast to the synchronous case), so | |
da17bf43 DW |
372 | * explicitly handle the special case of a 4 disk array with |
373 | * both data disks missing. | |
0a82a623 | 374 | */ |
da17bf43 DW |
375 | return __2data_recov_4(disks, bytes, faila, failb, blocks, submit); |
376 | case 3: | |
0a82a623 DW |
377 | /* dma devices do not uniformly understand a single |
378 | * source pq operation (in contrast to the synchronous | |
da17bf43 DW |
379 | * case), so explicitly handle the special case of a 5 disk |
380 | * array with 2 of 3 data disks missing. | |
0a82a623 | 381 | */ |
da17bf43 | 382 | return __2data_recov_5(disks, bytes, faila, failb, blocks, submit); |
0a82a623 DW |
383 | default: |
384 | return __2data_recov_n(disks, bytes, faila, failb, blocks, submit); | |
385 | } | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(async_raid6_2data_recov); | |
388 | ||
389 | /** | |
390 | * async_raid6_datap_recov - asynchronously calculate a data and the 'p' block | |
391 | * @disks: number of disks in the RAID-6 array | |
392 | * @bytes: block size | |
393 | * @faila: failed drive index | |
394 | * @blocks: array of source pointers where the last two entries are p and q | |
395 | * @submit: submission/completion modifiers | |
396 | */ | |
397 | struct dma_async_tx_descriptor * | |
398 | async_raid6_datap_recov(int disks, size_t bytes, int faila, | |
399 | struct page **blocks, struct async_submit_ctl *submit) | |
400 | { | |
401 | struct dma_async_tx_descriptor *tx = NULL; | |
402 | struct page *p, *q, *dq; | |
403 | u8 coef; | |
404 | enum async_tx_flags flags = submit->flags; | |
405 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
406 | void *cb_param = submit->cb_param; | |
407 | void *scribble = submit->scribble; | |
da17bf43 | 408 | int good_srcs, good, i; |
0a82a623 DW |
409 | struct page *srcs[2]; |
410 | ||
411 | pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes); | |
412 | ||
5157b4aa DW |
413 | /* if a dma resource is not available or a scribble buffer is not |
414 | * available punt to the synchronous path. In the 'dma not | |
415 | * available' case be sure to use the scribble buffer to | |
416 | * preserve the content of 'blocks' as the caller intended. | |
0a82a623 | 417 | */ |
5157b4aa DW |
418 | if (!async_dma_find_channel(DMA_PQ) || !scribble) { |
419 | void **ptrs = scribble ? scribble : (void **) blocks; | |
0a82a623 DW |
420 | |
421 | async_tx_quiesce(&submit->depend_tx); | |
422 | for (i = 0; i < disks; i++) | |
5dd33c9a N |
423 | if (blocks[i] == NULL) |
424 | ptrs[i] = (void*)raid6_empty_zero_page; | |
425 | else | |
426 | ptrs[i] = page_address(blocks[i]); | |
0a82a623 DW |
427 | |
428 | raid6_datap_recov(disks, bytes, faila, ptrs); | |
429 | ||
430 | async_tx_sync_epilog(submit); | |
431 | ||
432 | return NULL; | |
433 | } | |
434 | ||
da17bf43 DW |
435 | good_srcs = 0; |
436 | good = -1; | |
437 | for (i = 0; i < disks-2; i++) { | |
438 | if (i == faila) | |
439 | continue; | |
440 | if (blocks[i]) { | |
441 | good = i; | |
442 | good_srcs++; | |
443 | if (good_srcs > 1) | |
444 | break; | |
445 | } | |
446 | } | |
447 | BUG_ON(good_srcs == 0); | |
448 | ||
0a82a623 DW |
449 | p = blocks[disks-2]; |
450 | q = blocks[disks-1]; | |
451 | ||
452 | /* Compute syndrome with zero for the missing data page | |
453 | * Use the dead data page as temporary storage for delta q | |
454 | */ | |
455 | dq = blocks[faila]; | |
5dd33c9a | 456 | blocks[faila] = NULL; |
0a82a623 DW |
457 | blocks[disks-1] = dq; |
458 | ||
da17bf43 DW |
459 | /* in the 4-disk case we only need to perform a single source |
460 | * multiplication with the one good data block. | |
0a82a623 | 461 | */ |
da17bf43 | 462 | if (good_srcs == 1) { |
0a82a623 DW |
463 | struct page *g = blocks[good]; |
464 | ||
0403e382 DW |
465 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, |
466 | scribble); | |
0a82a623 DW |
467 | tx = async_memcpy(p, g, 0, 0, bytes, submit); |
468 | ||
0403e382 DW |
469 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, |
470 | scribble); | |
0a82a623 DW |
471 | tx = async_mult(dq, g, raid6_gfexp[good], bytes, submit); |
472 | } else { | |
0403e382 DW |
473 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, |
474 | scribble); | |
0a82a623 DW |
475 | tx = async_gen_syndrome(blocks, 0, disks, bytes, submit); |
476 | } | |
477 | ||
478 | /* Restore pointer table */ | |
479 | blocks[faila] = dq; | |
480 | blocks[disks-1] = q; | |
481 | ||
482 | /* calculate g^{-faila} */ | |
483 | coef = raid6_gfinv[raid6_gfexp[faila]]; | |
484 | ||
485 | srcs[0] = dq; | |
486 | srcs[1] = q; | |
0403e382 DW |
487 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
488 | NULL, NULL, scribble); | |
0a82a623 DW |
489 | tx = async_xor(dq, srcs, 0, 2, bytes, submit); |
490 | ||
0403e382 | 491 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
492 | tx = async_mult(dq, dq, coef, bytes, submit); |
493 | ||
494 | srcs[0] = p; | |
495 | srcs[1] = dq; | |
496 | init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn, | |
497 | cb_param, scribble); | |
498 | tx = async_xor(p, srcs, 0, 2, bytes, submit); | |
499 | ||
500 | return tx; | |
501 | } | |
502 | EXPORT_SYMBOL_GPL(async_raid6_datap_recov); | |
503 | ||
504 | MODULE_AUTHOR("Dan Williams <dan.j.williams@intel.com>"); | |
505 | MODULE_DESCRIPTION("asynchronous RAID-6 recovery api"); | |
506 | MODULE_LICENSE("GPL"); |