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fd534e9b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
0a82a623 DW |
2 | /* |
3 | * Asynchronous RAID-6 recovery calculations ASYNC_TX API. | |
4 | * Copyright(c) 2009 Intel Corporation | |
5 | * | |
6 | * based on raid6recov.c: | |
7 | * Copyright 2002 H. Peter Anvin | |
0a82a623 DW |
8 | */ |
9 | #include <linux/kernel.h> | |
10 | #include <linux/interrupt.h> | |
4bb33cc8 | 11 | #include <linux/module.h> |
0a82a623 DW |
12 | #include <linux/dma-mapping.h> |
13 | #include <linux/raid/pq.h> | |
14 | #include <linux/async_tx.h> | |
3bbdd498 | 15 | #include <linux/dmaengine.h> |
0a82a623 DW |
16 | |
17 | static struct dma_async_tx_descriptor * | |
18 | async_sum_product(struct page *dest, struct page **srcs, unsigned char *coef, | |
19 | size_t len, struct async_submit_ctl *submit) | |
20 | { | |
21 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ, | |
22 | &dest, 1, srcs, 2, len); | |
23 | struct dma_device *dma = chan ? chan->device : NULL; | |
3bbdd498 | 24 | struct dmaengine_unmap_data *unmap = NULL; |
0a82a623 DW |
25 | const u8 *amul, *bmul; |
26 | u8 ax, bx; | |
27 | u8 *a, *b, *c; | |
28 | ||
3bbdd498 | 29 | if (dma) |
b02bab6b | 30 | unmap = dmaengine_get_unmap_data(dma->dev, 3, GFP_NOWAIT); |
3bbdd498 DW |
31 | |
32 | if (unmap) { | |
0a82a623 | 33 | struct device *dev = dma->dev; |
3bbdd498 | 34 | dma_addr_t pq[2]; |
0a82a623 | 35 | struct dma_async_tx_descriptor *tx; |
0776ae7b | 36 | enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P; |
0a82a623 | 37 | |
0403e382 DW |
38 | if (submit->flags & ASYNC_TX_FENCE) |
39 | dma_flags |= DMA_PREP_FENCE; | |
3bbdd498 DW |
40 | unmap->addr[0] = dma_map_page(dev, srcs[0], 0, len, DMA_TO_DEVICE); |
41 | unmap->addr[1] = dma_map_page(dev, srcs[1], 0, len, DMA_TO_DEVICE); | |
42 | unmap->to_cnt = 2; | |
43 | ||
44 | unmap->addr[2] = dma_map_page(dev, dest, 0, len, DMA_BIDIRECTIONAL); | |
45 | unmap->bidi_cnt = 1; | |
46 | /* engine only looks at Q, but expects it to follow P */ | |
47 | pq[1] = unmap->addr[2]; | |
48 | ||
49 | unmap->len = len; | |
50 | tx = dma->device_prep_dma_pq(chan, pq, unmap->addr, 2, coef, | |
0a82a623 DW |
51 | len, dma_flags); |
52 | if (tx) { | |
3bbdd498 | 53 | dma_set_unmap(tx, unmap); |
0a82a623 | 54 | async_tx_submit(chan, tx, submit); |
3bbdd498 | 55 | dmaengine_unmap_put(unmap); |
0a82a623 DW |
56 | return tx; |
57 | } | |
1f6672d4 DW |
58 | |
59 | /* could not get a descriptor, unmap and fall through to | |
60 | * the synchronous path | |
61 | */ | |
3bbdd498 | 62 | dmaengine_unmap_put(unmap); |
0a82a623 DW |
63 | } |
64 | ||
65 | /* run the operation synchronously */ | |
66 | async_tx_quiesce(&submit->depend_tx); | |
67 | amul = raid6_gfmul[coef[0]]; | |
68 | bmul = raid6_gfmul[coef[1]]; | |
69 | a = page_address(srcs[0]); | |
70 | b = page_address(srcs[1]); | |
71 | c = page_address(dest); | |
72 | ||
73 | while (len--) { | |
74 | ax = amul[*a++]; | |
75 | bx = bmul[*b++]; | |
76 | *c++ = ax ^ bx; | |
77 | } | |
78 | ||
79 | return NULL; | |
80 | } | |
81 | ||
82 | static struct dma_async_tx_descriptor * | |
83 | async_mult(struct page *dest, struct page *src, u8 coef, size_t len, | |
84 | struct async_submit_ctl *submit) | |
85 | { | |
86 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ, | |
87 | &dest, 1, &src, 1, len); | |
88 | struct dma_device *dma = chan ? chan->device : NULL; | |
3bbdd498 | 89 | struct dmaengine_unmap_data *unmap = NULL; |
0a82a623 DW |
90 | const u8 *qmul; /* Q multiplier table */ |
91 | u8 *d, *s; | |
92 | ||
3bbdd498 | 93 | if (dma) |
b02bab6b | 94 | unmap = dmaengine_get_unmap_data(dma->dev, 3, GFP_NOWAIT); |
3bbdd498 DW |
95 | |
96 | if (unmap) { | |
0a82a623 | 97 | dma_addr_t dma_dest[2]; |
0a82a623 DW |
98 | struct device *dev = dma->dev; |
99 | struct dma_async_tx_descriptor *tx; | |
0776ae7b | 100 | enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P; |
0a82a623 | 101 | |
0403e382 DW |
102 | if (submit->flags & ASYNC_TX_FENCE) |
103 | dma_flags |= DMA_PREP_FENCE; | |
3bbdd498 DW |
104 | unmap->addr[0] = dma_map_page(dev, src, 0, len, DMA_TO_DEVICE); |
105 | unmap->to_cnt++; | |
106 | unmap->addr[1] = dma_map_page(dev, dest, 0, len, DMA_BIDIRECTIONAL); | |
107 | dma_dest[1] = unmap->addr[1]; | |
108 | unmap->bidi_cnt++; | |
109 | unmap->len = len; | |
110 | ||
111 | /* this looks funny, but the engine looks for Q at | |
112 | * dma_dest[1] and ignores dma_dest[0] as a dest | |
113 | * due to DMA_PREP_PQ_DISABLE_P | |
114 | */ | |
115 | tx = dma->device_prep_dma_pq(chan, dma_dest, unmap->addr, | |
116 | 1, &coef, len, dma_flags); | |
117 | ||
0a82a623 | 118 | if (tx) { |
3bbdd498 DW |
119 | dma_set_unmap(tx, unmap); |
120 | dmaengine_unmap_put(unmap); | |
0a82a623 DW |
121 | async_tx_submit(chan, tx, submit); |
122 | return tx; | |
123 | } | |
1f6672d4 DW |
124 | |
125 | /* could not get a descriptor, unmap and fall through to | |
126 | * the synchronous path | |
127 | */ | |
3bbdd498 | 128 | dmaengine_unmap_put(unmap); |
0a82a623 DW |
129 | } |
130 | ||
131 | /* no channel available, or failed to allocate a descriptor, so | |
132 | * perform the operation synchronously | |
133 | */ | |
134 | async_tx_quiesce(&submit->depend_tx); | |
135 | qmul = raid6_gfmul[coef]; | |
136 | d = page_address(dest); | |
137 | s = page_address(src); | |
138 | ||
139 | while (len--) | |
140 | *d++ = qmul[*s++]; | |
141 | ||
142 | return NULL; | |
143 | } | |
144 | ||
145 | static struct dma_async_tx_descriptor * | |
da17bf43 DW |
146 | __2data_recov_4(int disks, size_t bytes, int faila, int failb, |
147 | struct page **blocks, struct async_submit_ctl *submit) | |
0a82a623 DW |
148 | { |
149 | struct dma_async_tx_descriptor *tx = NULL; | |
150 | struct page *p, *q, *a, *b; | |
151 | struct page *srcs[2]; | |
152 | unsigned char coef[2]; | |
153 | enum async_tx_flags flags = submit->flags; | |
154 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
155 | void *cb_param = submit->cb_param; | |
156 | void *scribble = submit->scribble; | |
157 | ||
da17bf43 DW |
158 | p = blocks[disks-2]; |
159 | q = blocks[disks-1]; | |
0a82a623 DW |
160 | |
161 | a = blocks[faila]; | |
162 | b = blocks[failb]; | |
163 | ||
164 | /* in the 4 disk case P + Pxy == P and Q + Qxy == Q */ | |
165 | /* Dx = A*(P+Pxy) + B*(Q+Qxy) */ | |
166 | srcs[0] = p; | |
167 | srcs[1] = q; | |
168 | coef[0] = raid6_gfexi[failb-faila]; | |
169 | coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]; | |
0403e382 | 170 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
171 | tx = async_sum_product(b, srcs, coef, bytes, submit); |
172 | ||
173 | /* Dy = P+Pxy+Dx */ | |
174 | srcs[0] = p; | |
175 | srcs[1] = b; | |
176 | init_async_submit(submit, flags | ASYNC_TX_XOR_ZERO_DST, tx, cb_fn, | |
177 | cb_param, scribble); | |
178 | tx = async_xor(a, srcs, 0, 2, bytes, submit); | |
179 | ||
180 | return tx; | |
181 | ||
182 | } | |
183 | ||
184 | static struct dma_async_tx_descriptor * | |
da17bf43 DW |
185 | __2data_recov_5(int disks, size_t bytes, int faila, int failb, |
186 | struct page **blocks, struct async_submit_ctl *submit) | |
0a82a623 DW |
187 | { |
188 | struct dma_async_tx_descriptor *tx = NULL; | |
189 | struct page *p, *q, *g, *dp, *dq; | |
190 | struct page *srcs[2]; | |
191 | unsigned char coef[2]; | |
192 | enum async_tx_flags flags = submit->flags; | |
193 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
194 | void *cb_param = submit->cb_param; | |
195 | void *scribble = submit->scribble; | |
da17bf43 | 196 | int good_srcs, good, i; |
0a82a623 | 197 | |
da17bf43 DW |
198 | good_srcs = 0; |
199 | good = -1; | |
200 | for (i = 0; i < disks-2; i++) { | |
201 | if (blocks[i] == NULL) | |
202 | continue; | |
0a82a623 DW |
203 | if (i == faila || i == failb) |
204 | continue; | |
da17bf43 DW |
205 | good = i; |
206 | good_srcs++; | |
0a82a623 | 207 | } |
da17bf43 | 208 | BUG_ON(good_srcs > 1); |
0a82a623 | 209 | |
da17bf43 DW |
210 | p = blocks[disks-2]; |
211 | q = blocks[disks-1]; | |
0a82a623 DW |
212 | g = blocks[good]; |
213 | ||
214 | /* Compute syndrome with zero for the missing data pages | |
215 | * Use the dead data pages as temporary storage for delta p and | |
216 | * delta q | |
217 | */ | |
218 | dp = blocks[faila]; | |
219 | dq = blocks[failb]; | |
220 | ||
0403e382 | 221 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 | 222 | tx = async_memcpy(dp, g, 0, 0, bytes, submit); |
0403e382 | 223 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
224 | tx = async_mult(dq, g, raid6_gfexp[good], bytes, submit); |
225 | ||
226 | /* compute P + Pxy */ | |
227 | srcs[0] = dp; | |
228 | srcs[1] = p; | |
0403e382 DW |
229 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
230 | NULL, NULL, scribble); | |
0a82a623 DW |
231 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); |
232 | ||
233 | /* compute Q + Qxy */ | |
234 | srcs[0] = dq; | |
235 | srcs[1] = q; | |
0403e382 DW |
236 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
237 | NULL, NULL, scribble); | |
0a82a623 DW |
238 | tx = async_xor(dq, srcs, 0, 2, bytes, submit); |
239 | ||
240 | /* Dx = A*(P+Pxy) + B*(Q+Qxy) */ | |
241 | srcs[0] = dp; | |
242 | srcs[1] = dq; | |
243 | coef[0] = raid6_gfexi[failb-faila]; | |
244 | coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]; | |
0403e382 | 245 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
246 | tx = async_sum_product(dq, srcs, coef, bytes, submit); |
247 | ||
248 | /* Dy = P+Pxy+Dx */ | |
249 | srcs[0] = dp; | |
250 | srcs[1] = dq; | |
251 | init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn, | |
252 | cb_param, scribble); | |
253 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); | |
254 | ||
255 | return tx; | |
256 | } | |
257 | ||
258 | static struct dma_async_tx_descriptor * | |
259 | __2data_recov_n(int disks, size_t bytes, int faila, int failb, | |
260 | struct page **blocks, struct async_submit_ctl *submit) | |
261 | { | |
262 | struct dma_async_tx_descriptor *tx = NULL; | |
263 | struct page *p, *q, *dp, *dq; | |
264 | struct page *srcs[2]; | |
265 | unsigned char coef[2]; | |
266 | enum async_tx_flags flags = submit->flags; | |
267 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
268 | void *cb_param = submit->cb_param; | |
269 | void *scribble = submit->scribble; | |
270 | ||
271 | p = blocks[disks-2]; | |
272 | q = blocks[disks-1]; | |
273 | ||
274 | /* Compute syndrome with zero for the missing data pages | |
275 | * Use the dead data pages as temporary storage for | |
276 | * delta p and delta q | |
277 | */ | |
278 | dp = blocks[faila]; | |
5dd33c9a | 279 | blocks[faila] = NULL; |
0a82a623 DW |
280 | blocks[disks-2] = dp; |
281 | dq = blocks[failb]; | |
5dd33c9a | 282 | blocks[failb] = NULL; |
0a82a623 DW |
283 | blocks[disks-1] = dq; |
284 | ||
0403e382 | 285 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
286 | tx = async_gen_syndrome(blocks, 0, disks, bytes, submit); |
287 | ||
288 | /* Restore pointer table */ | |
289 | blocks[faila] = dp; | |
290 | blocks[failb] = dq; | |
291 | blocks[disks-2] = p; | |
292 | blocks[disks-1] = q; | |
293 | ||
294 | /* compute P + Pxy */ | |
295 | srcs[0] = dp; | |
296 | srcs[1] = p; | |
0403e382 DW |
297 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
298 | NULL, NULL, scribble); | |
0a82a623 DW |
299 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); |
300 | ||
301 | /* compute Q + Qxy */ | |
302 | srcs[0] = dq; | |
303 | srcs[1] = q; | |
0403e382 DW |
304 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
305 | NULL, NULL, scribble); | |
0a82a623 DW |
306 | tx = async_xor(dq, srcs, 0, 2, bytes, submit); |
307 | ||
308 | /* Dx = A*(P+Pxy) + B*(Q+Qxy) */ | |
309 | srcs[0] = dp; | |
310 | srcs[1] = dq; | |
311 | coef[0] = raid6_gfexi[failb-faila]; | |
312 | coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]; | |
0403e382 | 313 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
314 | tx = async_sum_product(dq, srcs, coef, bytes, submit); |
315 | ||
316 | /* Dy = P+Pxy+Dx */ | |
317 | srcs[0] = dp; | |
318 | srcs[1] = dq; | |
319 | init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn, | |
320 | cb_param, scribble); | |
321 | tx = async_xor(dp, srcs, 0, 2, bytes, submit); | |
322 | ||
323 | return tx; | |
324 | } | |
325 | ||
326 | /** | |
327 | * async_raid6_2data_recov - asynchronously calculate two missing data blocks | |
328 | * @disks: number of disks in the RAID-6 array | |
329 | * @bytes: block size | |
330 | * @faila: first failed drive index | |
331 | * @failb: second failed drive index | |
332 | * @blocks: array of source pointers where the last two entries are p and q | |
333 | * @submit: submission/completion modifiers | |
334 | */ | |
335 | struct dma_async_tx_descriptor * | |
336 | async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb, | |
337 | struct page **blocks, struct async_submit_ctl *submit) | |
338 | { | |
5157b4aa | 339 | void *scribble = submit->scribble; |
da17bf43 DW |
340 | int non_zero_srcs, i; |
341 | ||
0a82a623 DW |
342 | BUG_ON(faila == failb); |
343 | if (failb < faila) | |
344 | swap(faila, failb); | |
345 | ||
346 | pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes); | |
347 | ||
5157b4aa DW |
348 | /* if a dma resource is not available or a scribble buffer is not |
349 | * available punt to the synchronous path. In the 'dma not | |
350 | * available' case be sure to use the scribble buffer to | |
351 | * preserve the content of 'blocks' as the caller intended. | |
0a82a623 | 352 | */ |
5157b4aa DW |
353 | if (!async_dma_find_channel(DMA_PQ) || !scribble) { |
354 | void **ptrs = scribble ? scribble : (void **) blocks; | |
0a82a623 DW |
355 | |
356 | async_tx_quiesce(&submit->depend_tx); | |
357 | for (i = 0; i < disks; i++) | |
5dd33c9a | 358 | if (blocks[i] == NULL) |
da17bf43 | 359 | ptrs[i] = (void *) raid6_empty_zero_page; |
5dd33c9a N |
360 | else |
361 | ptrs[i] = page_address(blocks[i]); | |
0a82a623 DW |
362 | |
363 | raid6_2data_recov(disks, bytes, faila, failb, ptrs); | |
364 | ||
365 | async_tx_sync_epilog(submit); | |
366 | ||
367 | return NULL; | |
368 | } | |
369 | ||
da17bf43 DW |
370 | non_zero_srcs = 0; |
371 | for (i = 0; i < disks-2 && non_zero_srcs < 4; i++) | |
372 | if (blocks[i]) | |
373 | non_zero_srcs++; | |
374 | switch (non_zero_srcs) { | |
375 | case 0: | |
376 | case 1: | |
377 | /* There must be at least 2 sources - the failed devices. */ | |
378 | BUG(); | |
379 | ||
380 | case 2: | |
0a82a623 DW |
381 | /* dma devices do not uniformly understand a zero source pq |
382 | * operation (in contrast to the synchronous case), so | |
da17bf43 DW |
383 | * explicitly handle the special case of a 4 disk array with |
384 | * both data disks missing. | |
0a82a623 | 385 | */ |
da17bf43 DW |
386 | return __2data_recov_4(disks, bytes, faila, failb, blocks, submit); |
387 | case 3: | |
0a82a623 DW |
388 | /* dma devices do not uniformly understand a single |
389 | * source pq operation (in contrast to the synchronous | |
da17bf43 DW |
390 | * case), so explicitly handle the special case of a 5 disk |
391 | * array with 2 of 3 data disks missing. | |
0a82a623 | 392 | */ |
da17bf43 | 393 | return __2data_recov_5(disks, bytes, faila, failb, blocks, submit); |
0a82a623 DW |
394 | default: |
395 | return __2data_recov_n(disks, bytes, faila, failb, blocks, submit); | |
396 | } | |
397 | } | |
398 | EXPORT_SYMBOL_GPL(async_raid6_2data_recov); | |
399 | ||
400 | /** | |
401 | * async_raid6_datap_recov - asynchronously calculate a data and the 'p' block | |
402 | * @disks: number of disks in the RAID-6 array | |
403 | * @bytes: block size | |
404 | * @faila: failed drive index | |
405 | * @blocks: array of source pointers where the last two entries are p and q | |
406 | * @submit: submission/completion modifiers | |
407 | */ | |
408 | struct dma_async_tx_descriptor * | |
409 | async_raid6_datap_recov(int disks, size_t bytes, int faila, | |
410 | struct page **blocks, struct async_submit_ctl *submit) | |
411 | { | |
412 | struct dma_async_tx_descriptor *tx = NULL; | |
413 | struct page *p, *q, *dq; | |
414 | u8 coef; | |
415 | enum async_tx_flags flags = submit->flags; | |
416 | dma_async_tx_callback cb_fn = submit->cb_fn; | |
417 | void *cb_param = submit->cb_param; | |
418 | void *scribble = submit->scribble; | |
da17bf43 | 419 | int good_srcs, good, i; |
0a82a623 DW |
420 | struct page *srcs[2]; |
421 | ||
422 | pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes); | |
423 | ||
5157b4aa DW |
424 | /* if a dma resource is not available or a scribble buffer is not |
425 | * available punt to the synchronous path. In the 'dma not | |
426 | * available' case be sure to use the scribble buffer to | |
427 | * preserve the content of 'blocks' as the caller intended. | |
0a82a623 | 428 | */ |
5157b4aa DW |
429 | if (!async_dma_find_channel(DMA_PQ) || !scribble) { |
430 | void **ptrs = scribble ? scribble : (void **) blocks; | |
0a82a623 DW |
431 | |
432 | async_tx_quiesce(&submit->depend_tx); | |
433 | for (i = 0; i < disks; i++) | |
5dd33c9a N |
434 | if (blocks[i] == NULL) |
435 | ptrs[i] = (void*)raid6_empty_zero_page; | |
436 | else | |
437 | ptrs[i] = page_address(blocks[i]); | |
0a82a623 DW |
438 | |
439 | raid6_datap_recov(disks, bytes, faila, ptrs); | |
440 | ||
441 | async_tx_sync_epilog(submit); | |
442 | ||
443 | return NULL; | |
444 | } | |
445 | ||
da17bf43 DW |
446 | good_srcs = 0; |
447 | good = -1; | |
448 | for (i = 0; i < disks-2; i++) { | |
449 | if (i == faila) | |
450 | continue; | |
451 | if (blocks[i]) { | |
452 | good = i; | |
453 | good_srcs++; | |
454 | if (good_srcs > 1) | |
455 | break; | |
456 | } | |
457 | } | |
458 | BUG_ON(good_srcs == 0); | |
459 | ||
0a82a623 DW |
460 | p = blocks[disks-2]; |
461 | q = blocks[disks-1]; | |
462 | ||
463 | /* Compute syndrome with zero for the missing data page | |
464 | * Use the dead data page as temporary storage for delta q | |
465 | */ | |
466 | dq = blocks[faila]; | |
5dd33c9a | 467 | blocks[faila] = NULL; |
0a82a623 DW |
468 | blocks[disks-1] = dq; |
469 | ||
da17bf43 DW |
470 | /* in the 4-disk case we only need to perform a single source |
471 | * multiplication with the one good data block. | |
0a82a623 | 472 | */ |
da17bf43 | 473 | if (good_srcs == 1) { |
0a82a623 DW |
474 | struct page *g = blocks[good]; |
475 | ||
0403e382 DW |
476 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, |
477 | scribble); | |
0a82a623 DW |
478 | tx = async_memcpy(p, g, 0, 0, bytes, submit); |
479 | ||
0403e382 DW |
480 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, |
481 | scribble); | |
0a82a623 DW |
482 | tx = async_mult(dq, g, raid6_gfexp[good], bytes, submit); |
483 | } else { | |
0403e382 DW |
484 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, |
485 | scribble); | |
0a82a623 DW |
486 | tx = async_gen_syndrome(blocks, 0, disks, bytes, submit); |
487 | } | |
488 | ||
489 | /* Restore pointer table */ | |
490 | blocks[faila] = dq; | |
491 | blocks[disks-1] = q; | |
492 | ||
493 | /* calculate g^{-faila} */ | |
494 | coef = raid6_gfinv[raid6_gfexp[faila]]; | |
495 | ||
496 | srcs[0] = dq; | |
497 | srcs[1] = q; | |
0403e382 DW |
498 | init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx, |
499 | NULL, NULL, scribble); | |
0a82a623 DW |
500 | tx = async_xor(dq, srcs, 0, 2, bytes, submit); |
501 | ||
0403e382 | 502 | init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble); |
0a82a623 DW |
503 | tx = async_mult(dq, dq, coef, bytes, submit); |
504 | ||
505 | srcs[0] = p; | |
506 | srcs[1] = dq; | |
507 | init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn, | |
508 | cb_param, scribble); | |
509 | tx = async_xor(p, srcs, 0, 2, bytes, submit); | |
510 | ||
511 | return tx; | |
512 | } | |
513 | EXPORT_SYMBOL_GPL(async_raid6_datap_recov); | |
514 | ||
515 | MODULE_AUTHOR("Dan Williams <dan.j.williams@intel.com>"); | |
516 | MODULE_DESCRIPTION("asynchronous RAID-6 recovery api"); | |
517 | MODULE_LICENSE("GPL"); |