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Commit | Line | Data |
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4a776f0a HS |
1 | /* |
2 | * DMA Engine test module | |
3 | * | |
4 | * Copyright (C) 2007 Atmel Corporation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | #include <linux/delay.h> | |
11 | #include <linux/dmaengine.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/kthread.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/moduleparam.h> | |
16 | #include <linux/random.h> | |
17 | #include <linux/wait.h> | |
18 | ||
19 | static unsigned int test_buf_size = 16384; | |
20 | module_param(test_buf_size, uint, S_IRUGO); | |
21 | MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer"); | |
22 | ||
06190d84 | 23 | static char test_channel[20]; |
4a776f0a HS |
24 | module_param_string(channel, test_channel, sizeof(test_channel), S_IRUGO); |
25 | MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)"); | |
26 | ||
06190d84 | 27 | static char test_device[20]; |
4a776f0a HS |
28 | module_param_string(device, test_device, sizeof(test_device), S_IRUGO); |
29 | MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)"); | |
30 | ||
31 | static unsigned int threads_per_chan = 1; | |
32 | module_param(threads_per_chan, uint, S_IRUGO); | |
33 | MODULE_PARM_DESC(threads_per_chan, | |
34 | "Number of threads to start per channel (default: 1)"); | |
35 | ||
36 | static unsigned int max_channels; | |
37 | module_param(max_channels, uint, S_IRUGO); | |
33df8ca0 | 38 | MODULE_PARM_DESC(max_channels, |
4a776f0a HS |
39 | "Maximum number of channels to use (default: all)"); |
40 | ||
b54d5cb9 DW |
41 | static unsigned int xor_sources = 3; |
42 | module_param(xor_sources, uint, S_IRUGO); | |
43 | MODULE_PARM_DESC(xor_sources, | |
44 | "Number of xor source buffers (default: 3)"); | |
45 | ||
4a776f0a HS |
46 | /* |
47 | * Initialization patterns. All bytes in the source buffer has bit 7 | |
48 | * set, all bytes in the destination buffer has bit 7 cleared. | |
49 | * | |
50 | * Bit 6 is set for all bytes which are to be copied by the DMA | |
51 | * engine. Bit 5 is set for all bytes which are to be overwritten by | |
52 | * the DMA engine. | |
53 | * | |
54 | * The remaining bits are the inverse of a counter which increments by | |
55 | * one for each byte address. | |
56 | */ | |
57 | #define PATTERN_SRC 0x80 | |
58 | #define PATTERN_DST 0x00 | |
59 | #define PATTERN_COPY 0x40 | |
60 | #define PATTERN_OVERWRITE 0x20 | |
61 | #define PATTERN_COUNT_MASK 0x1f | |
62 | ||
63 | struct dmatest_thread { | |
64 | struct list_head node; | |
65 | struct task_struct *task; | |
66 | struct dma_chan *chan; | |
b54d5cb9 DW |
67 | u8 **srcs; |
68 | u8 **dsts; | |
69 | enum dma_transaction_type type; | |
4a776f0a HS |
70 | }; |
71 | ||
72 | struct dmatest_chan { | |
73 | struct list_head node; | |
74 | struct dma_chan *chan; | |
75 | struct list_head threads; | |
76 | }; | |
77 | ||
78 | /* | |
79 | * These are protected by dma_list_mutex since they're only used by | |
33df8ca0 | 80 | * the DMA filter function callback |
4a776f0a HS |
81 | */ |
82 | static LIST_HEAD(dmatest_channels); | |
83 | static unsigned int nr_channels; | |
84 | ||
85 | static bool dmatest_match_channel(struct dma_chan *chan) | |
86 | { | |
87 | if (test_channel[0] == '\0') | |
88 | return true; | |
41d5e59c | 89 | return strcmp(dma_chan_name(chan), test_channel) == 0; |
4a776f0a HS |
90 | } |
91 | ||
92 | static bool dmatest_match_device(struct dma_device *device) | |
93 | { | |
94 | if (test_device[0] == '\0') | |
95 | return true; | |
06190d84 | 96 | return strcmp(dev_name(device->dev), test_device) == 0; |
4a776f0a HS |
97 | } |
98 | ||
99 | static unsigned long dmatest_random(void) | |
100 | { | |
101 | unsigned long buf; | |
102 | ||
103 | get_random_bytes(&buf, sizeof(buf)); | |
104 | return buf; | |
105 | } | |
106 | ||
b54d5cb9 | 107 | static void dmatest_init_srcs(u8 **bufs, unsigned int start, unsigned int len) |
4a776f0a HS |
108 | { |
109 | unsigned int i; | |
b54d5cb9 DW |
110 | u8 *buf; |
111 | ||
112 | for (; (buf = *bufs); bufs++) { | |
113 | for (i = 0; i < start; i++) | |
114 | buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK); | |
115 | for ( ; i < start + len; i++) | |
116 | buf[i] = PATTERN_SRC | PATTERN_COPY | |
117 | | (~i & PATTERN_COUNT_MASK);; | |
118 | for ( ; i < test_buf_size; i++) | |
119 | buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK); | |
120 | buf++; | |
121 | } | |
4a776f0a HS |
122 | } |
123 | ||
b54d5cb9 | 124 | static void dmatest_init_dsts(u8 **bufs, unsigned int start, unsigned int len) |
4a776f0a HS |
125 | { |
126 | unsigned int i; | |
b54d5cb9 DW |
127 | u8 *buf; |
128 | ||
129 | for (; (buf = *bufs); bufs++) { | |
130 | for (i = 0; i < start; i++) | |
131 | buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK); | |
132 | for ( ; i < start + len; i++) | |
133 | buf[i] = PATTERN_DST | PATTERN_OVERWRITE | |
134 | | (~i & PATTERN_COUNT_MASK); | |
135 | for ( ; i < test_buf_size; i++) | |
136 | buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK); | |
137 | } | |
4a776f0a HS |
138 | } |
139 | ||
140 | static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index, | |
141 | unsigned int counter, bool is_srcbuf) | |
142 | { | |
143 | u8 diff = actual ^ pattern; | |
144 | u8 expected = pattern | (~counter & PATTERN_COUNT_MASK); | |
145 | const char *thread_name = current->comm; | |
146 | ||
147 | if (is_srcbuf) | |
148 | pr_warning("%s: srcbuf[0x%x] overwritten!" | |
149 | " Expected %02x, got %02x\n", | |
150 | thread_name, index, expected, actual); | |
151 | else if ((pattern & PATTERN_COPY) | |
152 | && (diff & (PATTERN_COPY | PATTERN_OVERWRITE))) | |
153 | pr_warning("%s: dstbuf[0x%x] not copied!" | |
154 | " Expected %02x, got %02x\n", | |
155 | thread_name, index, expected, actual); | |
156 | else if (diff & PATTERN_SRC) | |
157 | pr_warning("%s: dstbuf[0x%x] was copied!" | |
158 | " Expected %02x, got %02x\n", | |
159 | thread_name, index, expected, actual); | |
160 | else | |
161 | pr_warning("%s: dstbuf[0x%x] mismatch!" | |
162 | " Expected %02x, got %02x\n", | |
163 | thread_name, index, expected, actual); | |
164 | } | |
165 | ||
b54d5cb9 | 166 | static unsigned int dmatest_verify(u8 **bufs, unsigned int start, |
4a776f0a HS |
167 | unsigned int end, unsigned int counter, u8 pattern, |
168 | bool is_srcbuf) | |
169 | { | |
170 | unsigned int i; | |
171 | unsigned int error_count = 0; | |
172 | u8 actual; | |
b54d5cb9 DW |
173 | u8 expected; |
174 | u8 *buf; | |
175 | unsigned int counter_orig = counter; | |
176 | ||
177 | for (; (buf = *bufs); bufs++) { | |
178 | counter = counter_orig; | |
179 | for (i = start; i < end; i++) { | |
180 | actual = buf[i]; | |
181 | expected = pattern | (~counter & PATTERN_COUNT_MASK); | |
182 | if (actual != expected) { | |
183 | if (error_count < 32) | |
184 | dmatest_mismatch(actual, pattern, i, | |
185 | counter, is_srcbuf); | |
186 | error_count++; | |
187 | } | |
188 | counter++; | |
4a776f0a | 189 | } |
4a776f0a HS |
190 | } |
191 | ||
192 | if (error_count > 32) | |
193 | pr_warning("%s: %u errors suppressed\n", | |
194 | current->comm, error_count - 32); | |
195 | ||
196 | return error_count; | |
197 | } | |
198 | ||
199 | /* | |
200 | * This function repeatedly tests DMA transfers of various lengths and | |
b54d5cb9 DW |
201 | * offsets for a given operation type until it is told to exit by |
202 | * kthread_stop(). There may be multiple threads running this function | |
203 | * in parallel for a single channel, and there may be multiple channels | |
204 | * being tested in parallel. | |
4a776f0a HS |
205 | * |
206 | * Before each test, the source and destination buffer is initialized | |
207 | * with a known pattern. This pattern is different depending on | |
208 | * whether it's in an area which is supposed to be copied or | |
209 | * overwritten, and different in the source and destination buffers. | |
210 | * So if the DMA engine doesn't copy exactly what we tell it to copy, | |
211 | * we'll notice. | |
212 | */ | |
213 | static int dmatest_func(void *data) | |
214 | { | |
215 | struct dmatest_thread *thread = data; | |
216 | struct dma_chan *chan; | |
217 | const char *thread_name; | |
218 | unsigned int src_off, dst_off, len; | |
219 | unsigned int error_count; | |
220 | unsigned int failed_tests = 0; | |
221 | unsigned int total_tests = 0; | |
222 | dma_cookie_t cookie; | |
223 | enum dma_status status; | |
b54d5cb9 | 224 | enum dma_ctrl_flags flags; |
4a776f0a | 225 | int ret; |
b54d5cb9 DW |
226 | int src_cnt; |
227 | int dst_cnt; | |
228 | int i; | |
4a776f0a HS |
229 | |
230 | thread_name = current->comm; | |
231 | ||
232 | ret = -ENOMEM; | |
4a776f0a HS |
233 | |
234 | smp_rmb(); | |
235 | chan = thread->chan; | |
b54d5cb9 DW |
236 | if (thread->type == DMA_MEMCPY) |
237 | src_cnt = dst_cnt = 1; | |
238 | else if (thread->type == DMA_XOR) { | |
239 | src_cnt = xor_sources | 1; /* force odd to ensure dst = src */ | |
240 | dst_cnt = 1; | |
241 | } else | |
242 | goto err_srcs; | |
243 | ||
244 | thread->srcs = kcalloc(src_cnt+1, sizeof(u8 *), GFP_KERNEL); | |
245 | if (!thread->srcs) | |
246 | goto err_srcs; | |
247 | for (i = 0; i < src_cnt; i++) { | |
248 | thread->srcs[i] = kmalloc(test_buf_size, GFP_KERNEL); | |
249 | if (!thread->srcs[i]) | |
250 | goto err_srcbuf; | |
251 | } | |
252 | thread->srcs[i] = NULL; | |
253 | ||
254 | thread->dsts = kcalloc(dst_cnt+1, sizeof(u8 *), GFP_KERNEL); | |
255 | if (!thread->dsts) | |
256 | goto err_dsts; | |
257 | for (i = 0; i < dst_cnt; i++) { | |
258 | thread->dsts[i] = kmalloc(test_buf_size, GFP_KERNEL); | |
259 | if (!thread->dsts[i]) | |
260 | goto err_dstbuf; | |
261 | } | |
262 | thread->dsts[i] = NULL; | |
263 | ||
264 | flags = DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP; | |
4a776f0a HS |
265 | |
266 | while (!kthread_should_stop()) { | |
d86be86e | 267 | struct dma_device *dev = chan->device; |
b54d5cb9 DW |
268 | struct dma_async_tx_descriptor *tx = NULL; |
269 | dma_addr_t dma_srcs[src_cnt]; | |
270 | dma_addr_t dma_dsts[dst_cnt]; | |
d86be86e | 271 | |
4a776f0a HS |
272 | total_tests++; |
273 | ||
274 | len = dmatest_random() % test_buf_size + 1; | |
275 | src_off = dmatest_random() % (test_buf_size - len + 1); | |
276 | dst_off = dmatest_random() % (test_buf_size - len + 1); | |
277 | ||
b54d5cb9 DW |
278 | dmatest_init_srcs(thread->srcs, src_off, len); |
279 | dmatest_init_dsts(thread->dsts, dst_off, len); | |
4a776f0a | 280 | |
b54d5cb9 DW |
281 | for (i = 0; i < src_cnt; i++) { |
282 | u8 *buf = thread->srcs[i] + src_off; | |
283 | ||
284 | dma_srcs[i] = dma_map_single(dev->dev, buf, len, | |
285 | DMA_TO_DEVICE); | |
286 | } | |
d86be86e | 287 | /* map with DMA_BIDIRECTIONAL to force writeback/invalidate */ |
b54d5cb9 DW |
288 | for (i = 0; i < dst_cnt; i++) { |
289 | dma_dsts[i] = dma_map_single(dev->dev, thread->dsts[i], | |
290 | test_buf_size, | |
291 | DMA_BIDIRECTIONAL); | |
292 | } | |
293 | ||
294 | if (thread->type == DMA_MEMCPY) | |
295 | tx = dev->device_prep_dma_memcpy(chan, | |
296 | dma_dsts[0] + dst_off, | |
297 | dma_srcs[0], len, | |
298 | flags); | |
299 | else if (thread->type == DMA_XOR) | |
300 | tx = dev->device_prep_dma_xor(chan, | |
301 | dma_dsts[0] + dst_off, | |
302 | dma_srcs, xor_sources, | |
303 | len, flags); | |
d86be86e | 304 | |
d86be86e | 305 | if (!tx) { |
b54d5cb9 DW |
306 | for (i = 0; i < src_cnt; i++) |
307 | dma_unmap_single(dev->dev, dma_srcs[i], len, | |
308 | DMA_TO_DEVICE); | |
309 | for (i = 0; i < dst_cnt; i++) | |
310 | dma_unmap_single(dev->dev, dma_dsts[i], | |
311 | test_buf_size, | |
312 | DMA_BIDIRECTIONAL); | |
d86be86e AN |
313 | pr_warning("%s: #%u: prep error with src_off=0x%x " |
314 | "dst_off=0x%x len=0x%x\n", | |
315 | thread_name, total_tests - 1, | |
316 | src_off, dst_off, len); | |
317 | msleep(100); | |
318 | failed_tests++; | |
319 | continue; | |
320 | } | |
321 | tx->callback = NULL; | |
322 | cookie = tx->tx_submit(tx); | |
323 | ||
4a776f0a HS |
324 | if (dma_submit_error(cookie)) { |
325 | pr_warning("%s: #%u: submit error %d with src_off=0x%x " | |
326 | "dst_off=0x%x len=0x%x\n", | |
327 | thread_name, total_tests - 1, cookie, | |
328 | src_off, dst_off, len); | |
329 | msleep(100); | |
330 | failed_tests++; | |
331 | continue; | |
332 | } | |
b54d5cb9 | 333 | dma_async_issue_pending(chan); |
4a776f0a HS |
334 | |
335 | do { | |
336 | msleep(1); | |
b54d5cb9 | 337 | status = dma_async_is_tx_complete( |
4a776f0a HS |
338 | chan, cookie, NULL, NULL); |
339 | } while (status == DMA_IN_PROGRESS); | |
340 | ||
341 | if (status == DMA_ERROR) { | |
342 | pr_warning("%s: #%u: error during copy\n", | |
343 | thread_name, total_tests - 1); | |
344 | failed_tests++; | |
345 | continue; | |
346 | } | |
d86be86e | 347 | /* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */ |
b54d5cb9 DW |
348 | for (i = 0; i < dst_cnt; i++) |
349 | dma_unmap_single(dev->dev, dma_dsts[i], test_buf_size, | |
350 | DMA_BIDIRECTIONAL); | |
4a776f0a HS |
351 | |
352 | error_count = 0; | |
353 | ||
354 | pr_debug("%s: verifying source buffer...\n", thread_name); | |
b54d5cb9 | 355 | error_count += dmatest_verify(thread->srcs, 0, src_off, |
4a776f0a | 356 | 0, PATTERN_SRC, true); |
b54d5cb9 | 357 | error_count += dmatest_verify(thread->srcs, src_off, |
4a776f0a HS |
358 | src_off + len, src_off, |
359 | PATTERN_SRC | PATTERN_COPY, true); | |
b54d5cb9 | 360 | error_count += dmatest_verify(thread->srcs, src_off + len, |
4a776f0a HS |
361 | test_buf_size, src_off + len, |
362 | PATTERN_SRC, true); | |
363 | ||
364 | pr_debug("%s: verifying dest buffer...\n", | |
365 | thread->task->comm); | |
b54d5cb9 | 366 | error_count += dmatest_verify(thread->dsts, 0, dst_off, |
4a776f0a | 367 | 0, PATTERN_DST, false); |
b54d5cb9 | 368 | error_count += dmatest_verify(thread->dsts, dst_off, |
4a776f0a HS |
369 | dst_off + len, src_off, |
370 | PATTERN_SRC | PATTERN_COPY, false); | |
b54d5cb9 | 371 | error_count += dmatest_verify(thread->dsts, dst_off + len, |
4a776f0a HS |
372 | test_buf_size, dst_off + len, |
373 | PATTERN_DST, false); | |
374 | ||
375 | if (error_count) { | |
376 | pr_warning("%s: #%u: %u errors with " | |
377 | "src_off=0x%x dst_off=0x%x len=0x%x\n", | |
378 | thread_name, total_tests - 1, error_count, | |
379 | src_off, dst_off, len); | |
380 | failed_tests++; | |
381 | } else { | |
382 | pr_debug("%s: #%u: No errors with " | |
383 | "src_off=0x%x dst_off=0x%x len=0x%x\n", | |
384 | thread_name, total_tests - 1, | |
385 | src_off, dst_off, len); | |
386 | } | |
387 | } | |
388 | ||
389 | ret = 0; | |
b54d5cb9 DW |
390 | for (i = 0; thread->dsts[i]; i++) |
391 | kfree(thread->dsts[i]); | |
4a776f0a | 392 | err_dstbuf: |
b54d5cb9 DW |
393 | kfree(thread->dsts); |
394 | err_dsts: | |
395 | for (i = 0; thread->srcs[i]; i++) | |
396 | kfree(thread->srcs[i]); | |
4a776f0a | 397 | err_srcbuf: |
b54d5cb9 DW |
398 | kfree(thread->srcs); |
399 | err_srcs: | |
4a776f0a HS |
400 | pr_notice("%s: terminating after %u tests, %u failures (status %d)\n", |
401 | thread_name, total_tests, failed_tests, ret); | |
402 | return ret; | |
403 | } | |
404 | ||
405 | static void dmatest_cleanup_channel(struct dmatest_chan *dtc) | |
406 | { | |
407 | struct dmatest_thread *thread; | |
408 | struct dmatest_thread *_thread; | |
409 | int ret; | |
410 | ||
411 | list_for_each_entry_safe(thread, _thread, &dtc->threads, node) { | |
412 | ret = kthread_stop(thread->task); | |
413 | pr_debug("dmatest: thread %s exited with status %d\n", | |
414 | thread->task->comm, ret); | |
415 | list_del(&thread->node); | |
416 | kfree(thread); | |
417 | } | |
418 | kfree(dtc); | |
419 | } | |
420 | ||
b54d5cb9 | 421 | static int dmatest_add_threads(struct dmatest_chan *dtc, enum dma_transaction_type type) |
4a776f0a | 422 | { |
b54d5cb9 DW |
423 | struct dmatest_thread *thread; |
424 | struct dma_chan *chan = dtc->chan; | |
425 | char *op; | |
426 | unsigned int i; | |
4a776f0a | 427 | |
b54d5cb9 DW |
428 | if (type == DMA_MEMCPY) |
429 | op = "copy"; | |
430 | else if (type == DMA_XOR) | |
431 | op = "xor"; | |
432 | else | |
433 | return -EINVAL; | |
4a776f0a HS |
434 | |
435 | for (i = 0; i < threads_per_chan; i++) { | |
436 | thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL); | |
437 | if (!thread) { | |
b54d5cb9 DW |
438 | pr_warning("dmatest: No memory for %s-%s%u\n", |
439 | dma_chan_name(chan), op, i); | |
440 | ||
4a776f0a HS |
441 | break; |
442 | } | |
443 | thread->chan = dtc->chan; | |
b54d5cb9 | 444 | thread->type = type; |
4a776f0a | 445 | smp_wmb(); |
b54d5cb9 DW |
446 | thread->task = kthread_run(dmatest_func, thread, "%s-%s%u", |
447 | dma_chan_name(chan), op, i); | |
4a776f0a | 448 | if (IS_ERR(thread->task)) { |
b54d5cb9 DW |
449 | pr_warning("dmatest: Failed to run thread %s-%s%u\n", |
450 | dma_chan_name(chan), op, i); | |
4a776f0a HS |
451 | kfree(thread); |
452 | break; | |
453 | } | |
454 | ||
455 | /* srcbuf and dstbuf are allocated by the thread itself */ | |
456 | ||
457 | list_add_tail(&thread->node, &dtc->threads); | |
458 | } | |
459 | ||
b54d5cb9 DW |
460 | return i; |
461 | } | |
462 | ||
463 | static int dmatest_add_channel(struct dma_chan *chan) | |
464 | { | |
465 | struct dmatest_chan *dtc; | |
466 | struct dma_device *dma_dev = chan->device; | |
467 | unsigned int thread_count = 0; | |
468 | unsigned int cnt; | |
469 | ||
470 | dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL); | |
471 | if (!dtc) { | |
472 | pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan)); | |
473 | return -ENOMEM; | |
474 | } | |
475 | ||
476 | dtc->chan = chan; | |
477 | INIT_LIST_HEAD(&dtc->threads); | |
478 | ||
479 | if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) { | |
480 | cnt = dmatest_add_threads(dtc, DMA_MEMCPY); | |
481 | thread_count += cnt > 0 ?: 0; | |
482 | } | |
483 | if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) { | |
484 | cnt = dmatest_add_threads(dtc, DMA_XOR); | |
485 | thread_count += cnt > 0 ?: 0; | |
486 | } | |
487 | ||
488 | pr_info("dmatest: Started %u threads using %s\n", | |
489 | thread_count, dma_chan_name(chan)); | |
4a776f0a HS |
490 | |
491 | list_add_tail(&dtc->node, &dmatest_channels); | |
492 | nr_channels++; | |
493 | ||
33df8ca0 | 494 | return 0; |
4a776f0a HS |
495 | } |
496 | ||
7dd60251 | 497 | static bool filter(struct dma_chan *chan, void *param) |
4a776f0a | 498 | { |
33df8ca0 | 499 | if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device)) |
7dd60251 | 500 | return false; |
33df8ca0 | 501 | else |
7dd60251 | 502 | return true; |
4a776f0a HS |
503 | } |
504 | ||
4a776f0a HS |
505 | static int __init dmatest_init(void) |
506 | { | |
33df8ca0 DW |
507 | dma_cap_mask_t mask; |
508 | struct dma_chan *chan; | |
509 | int err = 0; | |
510 | ||
511 | dma_cap_zero(mask); | |
512 | dma_cap_set(DMA_MEMCPY, mask); | |
513 | for (;;) { | |
514 | chan = dma_request_channel(mask, filter, NULL); | |
515 | if (chan) { | |
516 | err = dmatest_add_channel(chan); | |
517 | if (err == 0) | |
518 | continue; | |
519 | else { | |
520 | dma_release_channel(chan); | |
521 | break; /* add_channel failed, punt */ | |
522 | } | |
523 | } else | |
524 | break; /* no more channels available */ | |
525 | if (max_channels && nr_channels >= max_channels) | |
526 | break; /* we have all we need */ | |
527 | } | |
4a776f0a | 528 | |
33df8ca0 | 529 | return err; |
4a776f0a | 530 | } |
33df8ca0 DW |
531 | /* when compiled-in wait for drivers to load first */ |
532 | late_initcall(dmatest_init); | |
4a776f0a HS |
533 | |
534 | static void __exit dmatest_exit(void) | |
535 | { | |
33df8ca0 | 536 | struct dmatest_chan *dtc, *_dtc; |
7cbd4877 | 537 | struct dma_chan *chan; |
33df8ca0 DW |
538 | |
539 | list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) { | |
540 | list_del(&dtc->node); | |
7cbd4877 | 541 | chan = dtc->chan; |
33df8ca0 DW |
542 | dmatest_cleanup_channel(dtc); |
543 | pr_debug("dmatest: dropped channel %s\n", | |
7cbd4877 DW |
544 | dma_chan_name(chan)); |
545 | dma_release_channel(chan); | |
33df8ca0 | 546 | } |
4a776f0a HS |
547 | } |
548 | module_exit(dmatest_exit); | |
549 | ||
550 | MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>"); | |
551 | MODULE_LICENSE("GPL v2"); |