diff options
Diffstat (limited to 'crypto/async_tx/async_pq.c')
-rw-r--r-- | crypto/async_tx/async_pq.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c new file mode 100644 index 000000000000..b88db6d1dc65 --- /dev/null +++ b/crypto/async_tx/async_pq.c | |||
@@ -0,0 +1,395 @@ | |||
1 | /* | ||
2 | * Copyright(c) 2007 Yuri Tikhonov <yur@emcraft.com> | ||
3 | * Copyright(c) 2009 Intel Corporation | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify it | ||
6 | * under the terms of the GNU General Public License as published by the Free | ||
7 | * Software Foundation; either version 2 of the License, or (at your option) | ||
8 | * any later version. | ||
9 | * | ||
10 | * This program is distributed in the hope that it will be useful, but WITHOUT | ||
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
13 | * more details. | ||
14 | * | ||
15 | * You should have received a copy of the GNU General Public License along with | ||
16 | * this program; if not, write to the Free Software Foundation, Inc., 59 | ||
17 | * Temple Place - Suite 330, Boston, MA 02111-1307, USA. | ||
18 | * | ||
19 | * The full GNU General Public License is included in this distribution in the | ||
20 | * file called COPYING. | ||
21 | */ | ||
22 | #include <linux/kernel.h> | ||
23 | #include <linux/interrupt.h> | ||
24 | #include <linux/dma-mapping.h> | ||
25 | #include <linux/raid/pq.h> | ||
26 | #include <linux/async_tx.h> | ||
27 | |||
28 | /** | ||
29 | * scribble - space to hold throwaway P buffer for synchronous gen_syndrome | ||
30 | */ | ||
31 | static struct page *scribble; | ||
32 | |||
33 | static bool is_raid6_zero_block(struct page *p) | ||
34 | { | ||
35 | return p == (void *) raid6_empty_zero_page; | ||
36 | } | ||
37 | |||
38 | /* the struct page *blocks[] parameter passed to async_gen_syndrome() | ||
39 | * and async_syndrome_val() contains the 'P' destination address at | ||
40 | * blocks[disks-2] and the 'Q' destination address at blocks[disks-1] | ||
41 | * | ||
42 | * note: these are macros as they are used as lvalues | ||
43 | */ | ||
44 | #define P(b, d) (b[d-2]) | ||
45 | #define Q(b, d) (b[d-1]) | ||
46 | |||
47 | /** | ||
48 | * do_async_gen_syndrome - asynchronously calculate P and/or Q | ||
49 | */ | ||
50 | static __async_inline struct dma_async_tx_descriptor * | ||
51 | do_async_gen_syndrome(struct dma_chan *chan, struct page **blocks, | ||
52 | const unsigned char *scfs, unsigned int offset, int disks, | ||
53 | size_t len, dma_addr_t *dma_src, | ||
54 | struct async_submit_ctl *submit) | ||
55 | { | ||
56 | struct dma_async_tx_descriptor *tx = NULL; | ||
57 | struct dma_device *dma = chan->device; | ||
58 | enum dma_ctrl_flags dma_flags = 0; | ||
59 | enum async_tx_flags flags_orig = submit->flags; | ||
60 | dma_async_tx_callback cb_fn_orig = submit->cb_fn; | ||
61 | dma_async_tx_callback cb_param_orig = submit->cb_param; | ||
62 | int src_cnt = disks - 2; | ||
63 | unsigned char coefs[src_cnt]; | ||
64 | unsigned short pq_src_cnt; | ||
65 | dma_addr_t dma_dest[2]; | ||
66 | int src_off = 0; | ||
67 | int idx; | ||
68 | int i; | ||
69 | |||
70 | /* DMAs use destinations as sources, so use BIDIRECTIONAL mapping */ | ||
71 | if (P(blocks, disks)) | ||
72 | dma_dest[0] = dma_map_page(dma->dev, P(blocks, disks), offset, | ||
73 | len, DMA_BIDIRECTIONAL); | ||
74 | else | ||
75 | dma_flags |= DMA_PREP_PQ_DISABLE_P; | ||
76 | if (Q(blocks, disks)) | ||
77 | dma_dest[1] = dma_map_page(dma->dev, Q(blocks, disks), offset, | ||
78 | len, DMA_BIDIRECTIONAL); | ||
79 | else | ||
80 | dma_flags |= DMA_PREP_PQ_DISABLE_Q; | ||
81 | |||
82 | /* convert source addresses being careful to collapse 'empty' | ||
83 | * sources and update the coefficients accordingly | ||
84 | */ | ||
85 | for (i = 0, idx = 0; i < src_cnt; i++) { | ||
86 | if (is_raid6_zero_block(blocks[i])) | ||
87 | continue; | ||
88 | dma_src[idx] = dma_map_page(dma->dev, blocks[i], offset, len, | ||
89 | DMA_TO_DEVICE); | ||
90 | coefs[idx] = scfs[i]; | ||
91 | idx++; | ||
92 | } | ||
93 | src_cnt = idx; | ||
94 | |||
95 | while (src_cnt > 0) { | ||
96 | submit->flags = flags_orig; | ||
97 | pq_src_cnt = min(src_cnt, dma_maxpq(dma, dma_flags)); | ||
98 | /* if we are submitting additional pqs, leave the chain open, | ||
99 | * clear the callback parameters, and leave the destination | ||
100 | * buffers mapped | ||
101 | */ | ||
102 | if (src_cnt > pq_src_cnt) { | ||
103 | submit->flags &= ~ASYNC_TX_ACK; | ||
104 | submit->flags |= ASYNC_TX_FENCE; | ||
105 | dma_flags |= DMA_COMPL_SKIP_DEST_UNMAP; | ||
106 | submit->cb_fn = NULL; | ||
107 | submit->cb_param = NULL; | ||
108 | } else { | ||
109 | dma_flags &= ~DMA_COMPL_SKIP_DEST_UNMAP; | ||
110 | submit->cb_fn = cb_fn_orig; | ||
111 | submit->cb_param = cb_param_orig; | ||
112 | if (cb_fn_orig) | ||
113 | dma_flags |= DMA_PREP_INTERRUPT; | ||
114 | } | ||
115 | if (submit->flags & ASYNC_TX_FENCE) | ||
116 | dma_flags |= DMA_PREP_FENCE; | ||
117 | |||
118 | /* Since we have clobbered the src_list we are committed | ||
119 | * to doing this asynchronously. Drivers force forward | ||
120 | * progress in case they can not provide a descriptor | ||
121 | */ | ||
122 | for (;;) { | ||
123 | tx = dma->device_prep_dma_pq(chan, dma_dest, | ||
124 | &dma_src[src_off], | ||
125 | pq_src_cnt, | ||
126 | &coefs[src_off], len, | ||
127 | dma_flags); | ||
128 | if (likely(tx)) | ||
129 | break; | ||
130 | async_tx_quiesce(&submit->depend_tx); | ||
131 | dma_async_issue_pending(chan); | ||
132 | } | ||
133 | |||
134 | async_tx_submit(chan, tx, submit); | ||
135 | submit->depend_tx = tx; | ||
136 | |||
137 | /* drop completed sources */ | ||
138 | src_cnt -= pq_src_cnt; | ||
139 | src_off += pq_src_cnt; | ||
140 | |||
141 | dma_flags |= DMA_PREP_CONTINUE; | ||
142 | } | ||
143 | |||
144 | return tx; | ||
145 | } | ||
146 | |||
147 | /** | ||
148 | * do_sync_gen_syndrome - synchronously calculate a raid6 syndrome | ||
149 | */ | ||
150 | static void | ||
151 | do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks, | ||
152 | size_t len, struct async_submit_ctl *submit) | ||
153 | { | ||
154 | void **srcs; | ||
155 | int i; | ||
156 | |||
157 | if (submit->scribble) | ||
158 | srcs = submit->scribble; | ||
159 | else | ||
160 | srcs = (void **) blocks; | ||
161 | |||
162 | for (i = 0; i < disks; i++) { | ||
163 | if (is_raid6_zero_block(blocks[i])) { | ||
164 | BUG_ON(i > disks - 3); /* P or Q can't be zero */ | ||
165 | srcs[i] = blocks[i]; | ||
166 | } else | ||
167 | srcs[i] = page_address(blocks[i]) + offset; | ||
168 | } | ||
169 | raid6_call.gen_syndrome(disks, len, srcs); | ||
170 | async_tx_sync_epilog(submit); | ||
171 | } | ||
172 | |||
173 | /** | ||
174 | * async_gen_syndrome - asynchronously calculate a raid6 syndrome | ||
175 | * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1 | ||
176 | * @offset: common offset into each block (src and dest) to start transaction | ||
177 | * @disks: number of blocks (including missing P or Q, see below) | ||
178 | * @len: length of operation in bytes | ||
179 | * @submit: submission/completion modifiers | ||
180 | * | ||
181 | * General note: This routine assumes a field of GF(2^8) with a | ||
182 | * primitive polynomial of 0x11d and a generator of {02}. | ||
183 | * | ||
184 | * 'disks' note: callers can optionally omit either P or Q (but not | ||
185 | * both) from the calculation by setting blocks[disks-2] or | ||
186 | * blocks[disks-1] to NULL. When P or Q is omitted 'len' must be <= | ||
187 | * PAGE_SIZE as a temporary buffer of this size is used in the | ||
188 | * synchronous path. 'disks' always accounts for both destination | ||
189 | * buffers. | ||
190 | * | ||
191 | * 'blocks' note: if submit->scribble is NULL then the contents of | ||
192 | * 'blocks' may be overridden | ||
193 | */ | ||
194 | struct dma_async_tx_descriptor * | ||
195 | async_gen_syndrome(struct page **blocks, unsigned int offset, int disks, | ||
196 | size_t len, struct async_submit_ctl *submit) | ||
197 | { | ||
198 | int src_cnt = disks - 2; | ||
199 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ, | ||
200 | &P(blocks, disks), 2, | ||
201 | blocks, src_cnt, len); | ||
202 | struct dma_device *device = chan ? chan->device : NULL; | ||
203 | dma_addr_t *dma_src = NULL; | ||
204 | |||
205 | BUG_ON(disks > 255 || !(P(blocks, disks) || Q(blocks, disks))); | ||
206 | |||
207 | if (submit->scribble) | ||
208 | dma_src = submit->scribble; | ||
209 | else if (sizeof(dma_addr_t) <= sizeof(struct page *)) | ||
210 | dma_src = (dma_addr_t *) blocks; | ||
211 | |||
212 | if (dma_src && device && | ||
213 | (src_cnt <= dma_maxpq(device, 0) || | ||
214 | dma_maxpq(device, DMA_PREP_CONTINUE) > 0) && | ||
215 | is_dma_pq_aligned(device, offset, 0, len)) { | ||
216 | /* run the p+q asynchronously */ | ||
217 | pr_debug("%s: (async) disks: %d len: %zu\n", | ||
218 | __func__, disks, len); | ||
219 | return do_async_gen_syndrome(chan, blocks, raid6_gfexp, offset, | ||
220 | disks, len, dma_src, submit); | ||
221 | } | ||
222 | |||
223 | /* run the pq synchronously */ | ||
224 | pr_debug("%s: (sync) disks: %d len: %zu\n", __func__, disks, len); | ||
225 | |||
226 | /* wait for any prerequisite operations */ | ||
227 | async_tx_quiesce(&submit->depend_tx); | ||
228 | |||
229 | if (!P(blocks, disks)) { | ||
230 | P(blocks, disks) = scribble; | ||
231 | BUG_ON(len + offset > PAGE_SIZE); | ||
232 | } | ||
233 | if (!Q(blocks, disks)) { | ||
234 | Q(blocks, disks) = scribble; | ||
235 | BUG_ON(len + offset > PAGE_SIZE); | ||
236 | } | ||
237 | do_sync_gen_syndrome(blocks, offset, disks, len, submit); | ||
238 | |||
239 | return NULL; | ||
240 | } | ||
241 | EXPORT_SYMBOL_GPL(async_gen_syndrome); | ||
242 | |||
243 | /** | ||
244 | * async_syndrome_val - asynchronously validate a raid6 syndrome | ||
245 | * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1 | ||
246 | * @offset: common offset into each block (src and dest) to start transaction | ||
247 | * @disks: number of blocks (including missing P or Q, see below) | ||
248 | * @len: length of operation in bytes | ||
249 | * @pqres: on val failure SUM_CHECK_P_RESULT and/or SUM_CHECK_Q_RESULT are set | ||
250 | * @spare: temporary result buffer for the synchronous case | ||
251 | * @submit: submission / completion modifiers | ||
252 | * | ||
253 | * The same notes from async_gen_syndrome apply to the 'blocks', | ||
254 | * and 'disks' parameters of this routine. The synchronous path | ||
255 | * requires a temporary result buffer and submit->scribble to be | ||
256 | * specified. | ||
257 | */ | ||
258 | struct dma_async_tx_descriptor * | ||
259 | async_syndrome_val(struct page **blocks, unsigned int offset, int disks, | ||
260 | size_t len, enum sum_check_flags *pqres, struct page *spare, | ||
261 | struct async_submit_ctl *submit) | ||
262 | { | ||
263 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ_VAL, | ||
264 | NULL, 0, blocks, disks, | ||
265 | len); | ||
266 | struct dma_device *device = chan ? chan->device : NULL; | ||
267 | struct dma_async_tx_descriptor *tx; | ||
268 | enum dma_ctrl_flags dma_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0; | ||
269 | dma_addr_t *dma_src = NULL; | ||
270 | |||
271 | BUG_ON(disks < 4); | ||
272 | |||
273 | if (submit->scribble) | ||
274 | dma_src = submit->scribble; | ||
275 | else if (sizeof(dma_addr_t) <= sizeof(struct page *)) | ||
276 | dma_src = (dma_addr_t *) blocks; | ||
277 | |||
278 | if (dma_src && device && disks <= dma_maxpq(device, 0) && | ||
279 | is_dma_pq_aligned(device, offset, 0, len)) { | ||
280 | struct device *dev = device->dev; | ||
281 | dma_addr_t *pq = &dma_src[disks-2]; | ||
282 | int i; | ||
283 | |||
284 | pr_debug("%s: (async) disks: %d len: %zu\n", | ||
285 | __func__, disks, len); | ||
286 | if (!P(blocks, disks)) | ||
287 | dma_flags |= DMA_PREP_PQ_DISABLE_P; | ||
288 | if (!Q(blocks, disks)) | ||
289 | dma_flags |= DMA_PREP_PQ_DISABLE_Q; | ||
290 | if (submit->flags & ASYNC_TX_FENCE) | ||
291 | dma_flags |= DMA_PREP_FENCE; | ||
292 | for (i = 0; i < disks; i++) | ||
293 | if (likely(blocks[i])) { | ||
294 | BUG_ON(is_raid6_zero_block(blocks[i])); | ||
295 | dma_src[i] = dma_map_page(dev, blocks[i], | ||
296 | offset, len, | ||
297 | DMA_TO_DEVICE); | ||
298 | } | ||
299 | |||
300 | for (;;) { | ||
301 | tx = device->device_prep_dma_pq_val(chan, pq, dma_src, | ||
302 | disks - 2, | ||
303 | raid6_gfexp, | ||
304 | len, pqres, | ||
305 | dma_flags); | ||
306 | if (likely(tx)) | ||
307 | break; | ||
308 | async_tx_quiesce(&submit->depend_tx); | ||
309 | dma_async_issue_pending(chan); | ||
310 | } | ||
311 | async_tx_submit(chan, tx, submit); | ||
312 | |||
313 | return tx; | ||
314 | } else { | ||
315 | struct page *p_src = P(blocks, disks); | ||
316 | struct page *q_src = Q(blocks, disks); | ||
317 | enum async_tx_flags flags_orig = submit->flags; | ||
318 | dma_async_tx_callback cb_fn_orig = submit->cb_fn; | ||
319 | void *scribble = submit->scribble; | ||
320 | void *cb_param_orig = submit->cb_param; | ||
321 | void *p, *q, *s; | ||
322 | |||
323 | pr_debug("%s: (sync) disks: %d len: %zu\n", | ||
324 | __func__, disks, len); | ||
325 | |||
326 | /* caller must provide a temporary result buffer and | ||
327 | * allow the input parameters to be preserved | ||
328 | */ | ||
329 | BUG_ON(!spare || !scribble); | ||
330 | |||
331 | /* wait for any prerequisite operations */ | ||
332 | async_tx_quiesce(&submit->depend_tx); | ||
333 | |||
334 | /* recompute p and/or q into the temporary buffer and then | ||
335 | * check to see the result matches the current value | ||
336 | */ | ||
337 | tx = NULL; | ||
338 | *pqres = 0; | ||
339 | if (p_src) { | ||
340 | init_async_submit(submit, ASYNC_TX_XOR_ZERO_DST, NULL, | ||
341 | NULL, NULL, scribble); | ||
342 | tx = async_xor(spare, blocks, offset, disks-2, len, submit); | ||
343 | async_tx_quiesce(&tx); | ||
344 | p = page_address(p_src) + offset; | ||
345 | s = page_address(spare) + offset; | ||
346 | *pqres |= !!memcmp(p, s, len) << SUM_CHECK_P; | ||
347 | } | ||
348 | |||
349 | if (q_src) { | ||
350 | P(blocks, disks) = NULL; | ||
351 | Q(blocks, disks) = spare; | ||
352 | init_async_submit(submit, 0, NULL, NULL, NULL, scribble); | ||
353 | tx = async_gen_syndrome(blocks, offset, disks, len, submit); | ||
354 | async_tx_quiesce(&tx); | ||
355 | q = page_address(q_src) + offset; | ||
356 | s = page_address(spare) + offset; | ||
357 | *pqres |= !!memcmp(q, s, len) << SUM_CHECK_Q; | ||
358 | } | ||
359 | |||
360 | /* restore P, Q and submit */ | ||
361 | P(blocks, disks) = p_src; | ||
362 | Q(blocks, disks) = q_src; | ||
363 | |||
364 | submit->cb_fn = cb_fn_orig; | ||
365 | submit->cb_param = cb_param_orig; | ||
366 | submit->flags = flags_orig; | ||
367 | async_tx_sync_epilog(submit); | ||
368 | |||
369 | return NULL; | ||
370 | } | ||
371 | } | ||
372 | EXPORT_SYMBOL_GPL(async_syndrome_val); | ||
373 | |||
374 | static int __init async_pq_init(void) | ||
375 | { | ||
376 | scribble = alloc_page(GFP_KERNEL); | ||
377 | |||
378 | if (scribble) | ||
379 | return 0; | ||
380 | |||
381 | pr_err("%s: failed to allocate required spare page\n", __func__); | ||
382 | |||
383 | return -ENOMEM; | ||
384 | } | ||
385 | |||
386 | static void __exit async_pq_exit(void) | ||
387 | { | ||
388 | put_page(scribble); | ||
389 | } | ||
390 | |||
391 | module_init(async_pq_init); | ||
392 | module_exit(async_pq_exit); | ||
393 | |||
394 | MODULE_DESCRIPTION("asynchronous raid6 syndrome generation/validation"); | ||
395 | MODULE_LICENSE("GPL"); | ||