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1/*
2 * xor offload engine api
3 *
4 * Copyright © 2006, Intel Corporation.
5 *
6 * Dan Williams <dan.j.williams@intel.com>
7 *
8 * with architecture considerations by:
9 * Neil Brown <neilb@suse.de>
10 * Jeff Garzik <jeff@garzik.org>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms and conditions of the GNU General Public License,
14 * version 2, as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
19 * more details.
20 *
21 * You should have received a copy of the GNU General Public License along with
22 * this program; if not, write to the Free Software Foundation, Inc.,
23 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 */
26#include <linux/kernel.h>
27#include <linux/interrupt.h>
28#include <linux/module.h>
29#include <linux/mm.h>
30#include <linux/dma-mapping.h>
31#include <linux/raid/xor.h>
32#include <linux/async_tx.h>
33
34/* do_async_xor - dma map the pages and perform the xor with an engine */
35static __async_inline struct dma_async_tx_descriptor *
36do_async_xor(struct dma_chan *chan, struct dmaengine_unmap_data *unmap,
37 struct async_submit_ctl *submit)
38{
39 struct dma_device *dma = chan->device;
40 struct dma_async_tx_descriptor *tx = NULL;
41 dma_async_tx_callback cb_fn_orig = submit->cb_fn;
42 void *cb_param_orig = submit->cb_param;
43 enum async_tx_flags flags_orig = submit->flags;
44 enum dma_ctrl_flags dma_flags = 0;
45 int src_cnt = unmap->to_cnt;
46 int xor_src_cnt;
47 dma_addr_t dma_dest = unmap->addr[unmap->to_cnt];
48 dma_addr_t *src_list = unmap->addr;
49
50 while (src_cnt) {
51 dma_addr_t tmp;
52
53 submit->flags = flags_orig;
54 xor_src_cnt = min(src_cnt, (int)dma->max_xor);
55 /* if we are submitting additional xors, leave the chain open
56 * and clear the callback parameters
57 */
58 if (src_cnt > xor_src_cnt) {
59 submit->flags &= ~ASYNC_TX_ACK;
60 submit->flags |= ASYNC_TX_FENCE;
61 submit->cb_fn = NULL;
62 submit->cb_param = NULL;
63 } else {
64 submit->cb_fn = cb_fn_orig;
65 submit->cb_param = cb_param_orig;
66 }
67 if (submit->cb_fn)
68 dma_flags |= DMA_PREP_INTERRUPT;
69 if (submit->flags & ASYNC_TX_FENCE)
70 dma_flags |= DMA_PREP_FENCE;
71
72 /* Drivers force forward progress in case they can not provide a
73 * descriptor
74 */
75 tmp = src_list[0];
76 if (src_list > unmap->addr)
77 src_list[0] = dma_dest;
78 tx = dma->device_prep_dma_xor(chan, dma_dest, src_list,
79 xor_src_cnt, unmap->len,
80 dma_flags);
81
82 if (unlikely(!tx))
83 async_tx_quiesce(&submit->depend_tx);
84
85 /* spin wait for the preceding transactions to complete */
86 while (unlikely(!tx)) {
87 dma_async_issue_pending(chan);
88 tx = dma->device_prep_dma_xor(chan, dma_dest,
89 src_list,
90 xor_src_cnt, unmap->len,
91 dma_flags);
92 }
93 src_list[0] = tmp;
94
95 dma_set_unmap(tx, unmap);
96 async_tx_submit(chan, tx, submit);
97 submit->depend_tx = tx;
98
99 if (src_cnt > xor_src_cnt) {
100 /* drop completed sources */
101 src_cnt -= xor_src_cnt;
102 /* use the intermediate result a source */
103 src_cnt++;
104 src_list += xor_src_cnt - 1;
105 } else
106 break;
107 }
108
109 return tx;
110}
111
112static void
113do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
114 int src_cnt, size_t len, struct async_submit_ctl *submit)
115{
116 int i;
117 int xor_src_cnt = 0;
118 int src_off = 0;
119 void *dest_buf;
120 void **srcs;
121
122 if (submit->scribble)
123 srcs = submit->scribble;
124 else
125 srcs = (void **) src_list;
126
127 /* convert to buffer pointers */
128 for (i = 0; i < src_cnt; i++)
129 if (src_list[i])
130 srcs[xor_src_cnt++] = page_address(src_list[i]) + offset;
131 src_cnt = xor_src_cnt;
132 /* set destination address */
133 dest_buf = page_address(dest) + offset;
134
135 if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
136 memset(dest_buf, 0, len);
137
138 while (src_cnt > 0) {
139 /* process up to 'MAX_XOR_BLOCKS' sources */
140 xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
141 xor_blocks(xor_src_cnt, len, dest_buf, &srcs[src_off]);
142
143 /* drop completed sources */
144 src_cnt -= xor_src_cnt;
145 src_off += xor_src_cnt;
146 }
147
148 async_tx_sync_epilog(submit);
149}
150
151/**
152 * async_xor - attempt to xor a set of blocks with a dma engine.
153 * @dest: destination page
154 * @src_list: array of source pages
155 * @offset: common src/dst offset to start transaction
156 * @src_cnt: number of source pages
157 * @len: length in bytes
158 * @submit: submission / completion modifiers
159 *
160 * honored flags: ASYNC_TX_ACK, ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DST
161 *
162 * xor_blocks always uses the dest as a source so the
163 * ASYNC_TX_XOR_ZERO_DST flag must be set to not include dest data in
164 * the calculation. The assumption with dma eninges is that they only
165 * use the destination buffer as a source when it is explicity specified
166 * in the source list.
167 *
168 * src_list note: if the dest is also a source it must be at index zero.
169 * The contents of this array will be overwritten if a scribble region
170 * is not specified.
171 */
172struct dma_async_tx_descriptor *
173async_xor(struct page *dest, struct page **src_list, unsigned int offset,
174 int src_cnt, size_t len, struct async_submit_ctl *submit)
175{
176 struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR,
177 &dest, 1, src_list,
178 src_cnt, len);
179 struct dma_device *device = chan ? chan->device : NULL;
180 struct dmaengine_unmap_data *unmap = NULL;
181
182 BUG_ON(src_cnt <= 1);
183
184 if (device)
185 unmap = dmaengine_get_unmap_data(device->dev, src_cnt+1, GFP_NOWAIT);
186
187 if (unmap && is_dma_xor_aligned(device, offset, 0, len)) {
188 struct dma_async_tx_descriptor *tx;
189 int i, j;
190
191 /* run the xor asynchronously */
192 pr_debug("%s (async): len: %zu\n", __func__, len);
193
194 unmap->len = len;
195 for (i = 0, j = 0; i < src_cnt; i++) {
196 if (!src_list[i])
197 continue;
198 unmap->to_cnt++;
199 unmap->addr[j++] = dma_map_page(device->dev, src_list[i],
200 offset, len, DMA_TO_DEVICE);
201 }
202
203 /* map it bidirectional as it may be re-used as a source */
204 unmap->addr[j] = dma_map_page(device->dev, dest, offset, len,
205 DMA_BIDIRECTIONAL);
206 unmap->bidi_cnt = 1;
207
208 tx = do_async_xor(chan, unmap, submit);
209 dmaengine_unmap_put(unmap);
210 return tx;
211 } else {
212 dmaengine_unmap_put(unmap);
213 /* run the xor synchronously */
214 pr_debug("%s (sync): len: %zu\n", __func__, len);
215 WARN_ONCE(chan, "%s: no space for dma address conversion\n",
216 __func__);
217
218 /* in the sync case the dest is an implied source
219 * (assumes the dest is the first source)
220 */
221 if (submit->flags & ASYNC_TX_XOR_DROP_DST) {
222 src_cnt--;
223 src_list++;
224 }
225
226 /* wait for any prerequisite operations */
227 async_tx_quiesce(&submit->depend_tx);
228
229 do_sync_xor(dest, src_list, offset, src_cnt, len, submit);
230
231 return NULL;
232 }
233}
234EXPORT_SYMBOL_GPL(async_xor);
235
236static int page_is_zero(struct page *p, unsigned int offset, size_t len)
237{
238 return !memchr_inv(page_address(p) + offset, 0, len);
239}
240
241static inline struct dma_chan *
242xor_val_chan(struct async_submit_ctl *submit, struct page *dest,
243 struct page **src_list, int src_cnt, size_t len)
244{
245 #ifdef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
246 return NULL;
247 #endif
248 return async_tx_find_channel(submit, DMA_XOR_VAL, &dest, 1, src_list,
249 src_cnt, len);
250}
251
252/**
253 * async_xor_val - attempt a xor parity check with a dma engine.
254 * @dest: destination page used if the xor is performed synchronously
255 * @src_list: array of source pages
256 * @offset: offset in pages to start transaction
257 * @src_cnt: number of source pages
258 * @len: length in bytes
259 * @result: 0 if sum == 0 else non-zero
260 * @submit: submission / completion modifiers
261 *
262 * honored flags: ASYNC_TX_ACK
263 *
264 * src_list note: if the dest is also a source it must be at index zero.
265 * The contents of this array will be overwritten if a scribble region
266 * is not specified.
267 */
268struct dma_async_tx_descriptor *
269async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
270 int src_cnt, size_t len, enum sum_check_flags *result,
271 struct async_submit_ctl *submit)
272{
273 struct dma_chan *chan = xor_val_chan(submit, dest, src_list, src_cnt, len);
274 struct dma_device *device = chan ? chan->device : NULL;
275 struct dma_async_tx_descriptor *tx = NULL;
276 struct dmaengine_unmap_data *unmap = NULL;
277
278 BUG_ON(src_cnt <= 1);
279
280 if (device)
281 unmap = dmaengine_get_unmap_data(device->dev, src_cnt, GFP_NOWAIT);
282
283 if (unmap && src_cnt <= device->max_xor &&
284 is_dma_xor_aligned(device, offset, 0, len)) {
285 unsigned long dma_prep_flags = 0;
286 int i;
287
288 pr_debug("%s: (async) len: %zu\n", __func__, len);
289
290 if (submit->cb_fn)
291 dma_prep_flags |= DMA_PREP_INTERRUPT;
292 if (submit->flags & ASYNC_TX_FENCE)
293 dma_prep_flags |= DMA_PREP_FENCE;
294
295 for (i = 0; i < src_cnt; i++) {
296 unmap->addr[i] = dma_map_page(device->dev, src_list[i],
297 offset, len, DMA_TO_DEVICE);
298 unmap->to_cnt++;
299 }
300 unmap->len = len;
301
302 tx = device->device_prep_dma_xor_val(chan, unmap->addr, src_cnt,
303 len, result,
304 dma_prep_flags);
305 if (unlikely(!tx)) {
306 async_tx_quiesce(&submit->depend_tx);
307
308 while (!tx) {
309 dma_async_issue_pending(chan);
310 tx = device->device_prep_dma_xor_val(chan,
311 unmap->addr, src_cnt, len, result,
312 dma_prep_flags);
313 }
314 }
315 dma_set_unmap(tx, unmap);
316 async_tx_submit(chan, tx, submit);
317 } else {
318 enum async_tx_flags flags_orig = submit->flags;
319
320 pr_debug("%s: (sync) len: %zu\n", __func__, len);
321 WARN_ONCE(device && src_cnt <= device->max_xor,
322 "%s: no space for dma address conversion\n",
323 __func__);
324
325 submit->flags |= ASYNC_TX_XOR_DROP_DST;
326 submit->flags &= ~ASYNC_TX_ACK;
327
328 tx = async_xor(dest, src_list, offset, src_cnt, len, submit);
329
330 async_tx_quiesce(&tx);
331
332 *result = !page_is_zero(dest, offset, len) << SUM_CHECK_P;
333
334 async_tx_sync_epilog(submit);
335 submit->flags = flags_orig;
336 }
337 dmaengine_unmap_put(unmap);
338
339 return tx;
340}
341EXPORT_SYMBOL_GPL(async_xor_val);
342
343MODULE_AUTHOR("Intel Corporation");
344MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
345MODULE_LICENSE("GPL");
1/*
2 * xor offload engine api
3 *
4 * Copyright © 2006, Intel Corporation.
5 *
6 * Dan Williams <dan.j.williams@intel.com>
7 *
8 * with architecture considerations by:
9 * Neil Brown <neilb@suse.de>
10 * Jeff Garzik <jeff@garzik.org>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms and conditions of the GNU General Public License,
14 * version 2, as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
19 * more details.
20 *
21 * You should have received a copy of the GNU General Public License along with
22 * this program; if not, write to the Free Software Foundation, Inc.,
23 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 */
26#include <linux/kernel.h>
27#include <linux/interrupt.h>
28#include <linux/mm.h>
29#include <linux/dma-mapping.h>
30#include <linux/raid/xor.h>
31#include <linux/async_tx.h>
32
33/* do_async_xor - dma map the pages and perform the xor with an engine */
34static __async_inline struct dma_async_tx_descriptor *
35do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
36 unsigned int offset, int src_cnt, size_t len, dma_addr_t *dma_src,
37 struct async_submit_ctl *submit)
38{
39 struct dma_device *dma = chan->device;
40 struct dma_async_tx_descriptor *tx = NULL;
41 int src_off = 0;
42 int i;
43 dma_async_tx_callback cb_fn_orig = submit->cb_fn;
44 void *cb_param_orig = submit->cb_param;
45 enum async_tx_flags flags_orig = submit->flags;
46 enum dma_ctrl_flags dma_flags;
47 int xor_src_cnt = 0;
48 dma_addr_t dma_dest;
49
50 /* map the dest bidrectional in case it is re-used as a source */
51 dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);
52 for (i = 0; i < src_cnt; i++) {
53 /* only map the dest once */
54 if (!src_list[i])
55 continue;
56 if (unlikely(src_list[i] == dest)) {
57 dma_src[xor_src_cnt++] = dma_dest;
58 continue;
59 }
60 dma_src[xor_src_cnt++] = dma_map_page(dma->dev, src_list[i], offset,
61 len, DMA_TO_DEVICE);
62 }
63 src_cnt = xor_src_cnt;
64
65 while (src_cnt) {
66 submit->flags = flags_orig;
67 dma_flags = 0;
68 xor_src_cnt = min(src_cnt, (int)dma->max_xor);
69 /* if we are submitting additional xors, leave the chain open,
70 * clear the callback parameters, and leave the destination
71 * buffer mapped
72 */
73 if (src_cnt > xor_src_cnt) {
74 submit->flags &= ~ASYNC_TX_ACK;
75 submit->flags |= ASYNC_TX_FENCE;
76 dma_flags = DMA_COMPL_SKIP_DEST_UNMAP;
77 submit->cb_fn = NULL;
78 submit->cb_param = NULL;
79 } else {
80 submit->cb_fn = cb_fn_orig;
81 submit->cb_param = cb_param_orig;
82 }
83 if (submit->cb_fn)
84 dma_flags |= DMA_PREP_INTERRUPT;
85 if (submit->flags & ASYNC_TX_FENCE)
86 dma_flags |= DMA_PREP_FENCE;
87 /* Since we have clobbered the src_list we are committed
88 * to doing this asynchronously. Drivers force forward progress
89 * in case they can not provide a descriptor
90 */
91 tx = dma->device_prep_dma_xor(chan, dma_dest, &dma_src[src_off],
92 xor_src_cnt, len, dma_flags);
93
94 if (unlikely(!tx))
95 async_tx_quiesce(&submit->depend_tx);
96
97 /* spin wait for the preceding transactions to complete */
98 while (unlikely(!tx)) {
99 dma_async_issue_pending(chan);
100 tx = dma->device_prep_dma_xor(chan, dma_dest,
101 &dma_src[src_off],
102 xor_src_cnt, len,
103 dma_flags);
104 }
105
106 async_tx_submit(chan, tx, submit);
107 submit->depend_tx = tx;
108
109 if (src_cnt > xor_src_cnt) {
110 /* drop completed sources */
111 src_cnt -= xor_src_cnt;
112 src_off += xor_src_cnt;
113
114 /* use the intermediate result a source */
115 dma_src[--src_off] = dma_dest;
116 src_cnt++;
117 } else
118 break;
119 }
120
121 return tx;
122}
123
124static void
125do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
126 int src_cnt, size_t len, struct async_submit_ctl *submit)
127{
128 int i;
129 int xor_src_cnt = 0;
130 int src_off = 0;
131 void *dest_buf;
132 void **srcs;
133
134 if (submit->scribble)
135 srcs = submit->scribble;
136 else
137 srcs = (void **) src_list;
138
139 /* convert to buffer pointers */
140 for (i = 0; i < src_cnt; i++)
141 if (src_list[i])
142 srcs[xor_src_cnt++] = page_address(src_list[i]) + offset;
143 src_cnt = xor_src_cnt;
144 /* set destination address */
145 dest_buf = page_address(dest) + offset;
146
147 if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
148 memset(dest_buf, 0, len);
149
150 while (src_cnt > 0) {
151 /* process up to 'MAX_XOR_BLOCKS' sources */
152 xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
153 xor_blocks(xor_src_cnt, len, dest_buf, &srcs[src_off]);
154
155 /* drop completed sources */
156 src_cnt -= xor_src_cnt;
157 src_off += xor_src_cnt;
158 }
159
160 async_tx_sync_epilog(submit);
161}
162
163/**
164 * async_xor - attempt to xor a set of blocks with a dma engine.
165 * @dest: destination page
166 * @src_list: array of source pages
167 * @offset: common src/dst offset to start transaction
168 * @src_cnt: number of source pages
169 * @len: length in bytes
170 * @submit: submission / completion modifiers
171 *
172 * honored flags: ASYNC_TX_ACK, ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DST
173 *
174 * xor_blocks always uses the dest as a source so the
175 * ASYNC_TX_XOR_ZERO_DST flag must be set to not include dest data in
176 * the calculation. The assumption with dma eninges is that they only
177 * use the destination buffer as a source when it is explicity specified
178 * in the source list.
179 *
180 * src_list note: if the dest is also a source it must be at index zero.
181 * The contents of this array will be overwritten if a scribble region
182 * is not specified.
183 */
184struct dma_async_tx_descriptor *
185async_xor(struct page *dest, struct page **src_list, unsigned int offset,
186 int src_cnt, size_t len, struct async_submit_ctl *submit)
187{
188 struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR,
189 &dest, 1, src_list,
190 src_cnt, len);
191 dma_addr_t *dma_src = NULL;
192
193 BUG_ON(src_cnt <= 1);
194
195 if (submit->scribble)
196 dma_src = submit->scribble;
197 else if (sizeof(dma_addr_t) <= sizeof(struct page *))
198 dma_src = (dma_addr_t *) src_list;
199
200 if (dma_src && chan && is_dma_xor_aligned(chan->device, offset, 0, len)) {
201 /* run the xor asynchronously */
202 pr_debug("%s (async): len: %zu\n", __func__, len);
203
204 return do_async_xor(chan, dest, src_list, offset, src_cnt, len,
205 dma_src, submit);
206 } else {
207 /* run the xor synchronously */
208 pr_debug("%s (sync): len: %zu\n", __func__, len);
209 WARN_ONCE(chan, "%s: no space for dma address conversion\n",
210 __func__);
211
212 /* in the sync case the dest is an implied source
213 * (assumes the dest is the first source)
214 */
215 if (submit->flags & ASYNC_TX_XOR_DROP_DST) {
216 src_cnt--;
217 src_list++;
218 }
219
220 /* wait for any prerequisite operations */
221 async_tx_quiesce(&submit->depend_tx);
222
223 do_sync_xor(dest, src_list, offset, src_cnt, len, submit);
224
225 return NULL;
226 }
227}
228EXPORT_SYMBOL_GPL(async_xor);
229
230static int page_is_zero(struct page *p, unsigned int offset, size_t len)
231{
232 char *a = page_address(p) + offset;
233 return ((*(u32 *) a) == 0 &&
234 memcmp(a, a + 4, len - 4) == 0);
235}
236
237static inline struct dma_chan *
238xor_val_chan(struct async_submit_ctl *submit, struct page *dest,
239 struct page **src_list, int src_cnt, size_t len)
240{
241 #ifdef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
242 return NULL;
243 #endif
244 return async_tx_find_channel(submit, DMA_XOR_VAL, &dest, 1, src_list,
245 src_cnt, len);
246}
247
248/**
249 * async_xor_val - attempt a xor parity check with a dma engine.
250 * @dest: destination page used if the xor is performed synchronously
251 * @src_list: array of source pages
252 * @offset: offset in pages to start transaction
253 * @src_cnt: number of source pages
254 * @len: length in bytes
255 * @result: 0 if sum == 0 else non-zero
256 * @submit: submission / completion modifiers
257 *
258 * honored flags: ASYNC_TX_ACK
259 *
260 * src_list note: if the dest is also a source it must be at index zero.
261 * The contents of this array will be overwritten if a scribble region
262 * is not specified.
263 */
264struct dma_async_tx_descriptor *
265async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
266 int src_cnt, size_t len, enum sum_check_flags *result,
267 struct async_submit_ctl *submit)
268{
269 struct dma_chan *chan = xor_val_chan(submit, dest, src_list, src_cnt, len);
270 struct dma_device *device = chan ? chan->device : NULL;
271 struct dma_async_tx_descriptor *tx = NULL;
272 dma_addr_t *dma_src = NULL;
273
274 BUG_ON(src_cnt <= 1);
275
276 if (submit->scribble)
277 dma_src = submit->scribble;
278 else if (sizeof(dma_addr_t) <= sizeof(struct page *))
279 dma_src = (dma_addr_t *) src_list;
280
281 if (dma_src && device && src_cnt <= device->max_xor &&
282 is_dma_xor_aligned(device, offset, 0, len)) {
283 unsigned long dma_prep_flags = 0;
284 int i;
285
286 pr_debug("%s: (async) len: %zu\n", __func__, len);
287
288 if (submit->cb_fn)
289 dma_prep_flags |= DMA_PREP_INTERRUPT;
290 if (submit->flags & ASYNC_TX_FENCE)
291 dma_prep_flags |= DMA_PREP_FENCE;
292 for (i = 0; i < src_cnt; i++)
293 dma_src[i] = dma_map_page(device->dev, src_list[i],
294 offset, len, DMA_TO_DEVICE);
295
296 tx = device->device_prep_dma_xor_val(chan, dma_src, src_cnt,
297 len, result,
298 dma_prep_flags);
299 if (unlikely(!tx)) {
300 async_tx_quiesce(&submit->depend_tx);
301
302 while (!tx) {
303 dma_async_issue_pending(chan);
304 tx = device->device_prep_dma_xor_val(chan,
305 dma_src, src_cnt, len, result,
306 dma_prep_flags);
307 }
308 }
309
310 async_tx_submit(chan, tx, submit);
311 } else {
312 enum async_tx_flags flags_orig = submit->flags;
313
314 pr_debug("%s: (sync) len: %zu\n", __func__, len);
315 WARN_ONCE(device && src_cnt <= device->max_xor,
316 "%s: no space for dma address conversion\n",
317 __func__);
318
319 submit->flags |= ASYNC_TX_XOR_DROP_DST;
320 submit->flags &= ~ASYNC_TX_ACK;
321
322 tx = async_xor(dest, src_list, offset, src_cnt, len, submit);
323
324 async_tx_quiesce(&tx);
325
326 *result = !page_is_zero(dest, offset, len) << SUM_CHECK_P;
327
328 async_tx_sync_epilog(submit);
329 submit->flags = flags_orig;
330 }
331
332 return tx;
333}
334EXPORT_SYMBOL_GPL(async_xor_val);
335
336MODULE_AUTHOR("Intel Corporation");
337MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
338MODULE_LICENSE("GPL");