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
23 static char test_channel[20];
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
27 static char test_device[20];
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);
38 MODULE_PARM_DESC(max_channels,
39 "Maximum number of channels to use (default: all)");
40
41 /*
42 * Initialization patterns. All bytes in the source buffer has bit 7
43 * set, all bytes in the destination buffer has bit 7 cleared.
44 *
45 * Bit 6 is set for all bytes which are to be copied by the DMA
46 * engine. Bit 5 is set for all bytes which are to be overwritten by
47 * the DMA engine.
48 *
49 * The remaining bits are the inverse of a counter which increments by
50 * one for each byte address.
51 */
52 #define PATTERN_SRC 0x80
53 #define PATTERN_DST 0x00
54 #define PATTERN_COPY 0x40
55 #define PATTERN_OVERWRITE 0x20
56 #define PATTERN_COUNT_MASK 0x1f
57
58 struct dmatest_thread {
59 struct list_head node;
60 struct task_struct *task;
61 struct dma_chan *chan;
62 u8 *srcbuf;
63 u8 *dstbuf;
64 };
65
66 struct dmatest_chan {
67 struct list_head node;
68 struct dma_chan *chan;
69 struct list_head threads;
70 };
71
72 /*
73 * These are protected by dma_list_mutex since they're only used by
74 * the DMA filter function callback
75 */
76 static LIST_HEAD(dmatest_channels);
77 static unsigned int nr_channels;
78
dmatest_match_channel(struct dma_chan * chan)79 static bool dmatest_match_channel(struct dma_chan *chan)
80 {
81 if (test_channel[0] == '\0')
82 return true;
83 return strcmp(dma_chan_name(chan), test_channel) == 0;
84 }
85
dmatest_match_device(struct dma_device * device)86 static bool dmatest_match_device(struct dma_device *device)
87 {
88 if (test_device[0] == '\0')
89 return true;
90 return strcmp(dev_name(device->dev), test_device) == 0;
91 }
92
dmatest_random(void)93 static unsigned long dmatest_random(void)
94 {
95 unsigned long buf;
96
97 get_random_bytes(&buf, sizeof(buf));
98 return buf;
99 }
100
dmatest_init_srcbuf(u8 * buf,unsigned int start,unsigned int len)101 static void dmatest_init_srcbuf(u8 *buf, unsigned int start, unsigned int len)
102 {
103 unsigned int i;
104
105 for (i = 0; i < start; i++)
106 buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
107 for ( ; i < start + len; i++)
108 buf[i] = PATTERN_SRC | PATTERN_COPY
109 | (~i & PATTERN_COUNT_MASK);;
110 for ( ; i < test_buf_size; i++)
111 buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
112 }
113
dmatest_init_dstbuf(u8 * buf,unsigned int start,unsigned int len)114 static void dmatest_init_dstbuf(u8 *buf, unsigned int start, unsigned int len)
115 {
116 unsigned int i;
117
118 for (i = 0; i < start; i++)
119 buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
120 for ( ; i < start + len; i++)
121 buf[i] = PATTERN_DST | PATTERN_OVERWRITE
122 | (~i & PATTERN_COUNT_MASK);
123 for ( ; i < test_buf_size; i++)
124 buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
125 }
126
dmatest_mismatch(u8 actual,u8 pattern,unsigned int index,unsigned int counter,bool is_srcbuf)127 static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
128 unsigned int counter, bool is_srcbuf)
129 {
130 u8 diff = actual ^ pattern;
131 u8 expected = pattern | (~counter & PATTERN_COUNT_MASK);
132 const char *thread_name = current->comm;
133
134 if (is_srcbuf)
135 pr_warning("%s: srcbuf[0x%x] overwritten!"
136 " Expected %02x, got %02x\n",
137 thread_name, index, expected, actual);
138 else if ((pattern & PATTERN_COPY)
139 && (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
140 pr_warning("%s: dstbuf[0x%x] not copied!"
141 " Expected %02x, got %02x\n",
142 thread_name, index, expected, actual);
143 else if (diff & PATTERN_SRC)
144 pr_warning("%s: dstbuf[0x%x] was copied!"
145 " Expected %02x, got %02x\n",
146 thread_name, index, expected, actual);
147 else
148 pr_warning("%s: dstbuf[0x%x] mismatch!"
149 " Expected %02x, got %02x\n",
150 thread_name, index, expected, actual);
151 }
152
dmatest_verify(u8 * buf,unsigned int start,unsigned int end,unsigned int counter,u8 pattern,bool is_srcbuf)153 static unsigned int dmatest_verify(u8 *buf, unsigned int start,
154 unsigned int end, unsigned int counter, u8 pattern,
155 bool is_srcbuf)
156 {
157 unsigned int i;
158 unsigned int error_count = 0;
159 u8 actual;
160
161 for (i = start; i < end; i++) {
162 actual = buf[i];
163 if (actual != (pattern | (~counter & PATTERN_COUNT_MASK))) {
164 if (error_count < 32)
165 dmatest_mismatch(actual, pattern, i, counter,
166 is_srcbuf);
167 error_count++;
168 }
169 counter++;
170 }
171
172 if (error_count > 32)
173 pr_warning("%s: %u errors suppressed\n",
174 current->comm, error_count - 32);
175
176 return error_count;
177 }
178
179 /*
180 * This function repeatedly tests DMA transfers of various lengths and
181 * offsets until it is told to exit by kthread_stop(). There may be
182 * multiple threads running this function in parallel for a single
183 * channel, and there may be multiple channels being tested in
184 * parallel.
185 *
186 * Before each test, the source and destination buffer is initialized
187 * with a known pattern. This pattern is different depending on
188 * whether it's in an area which is supposed to be copied or
189 * overwritten, and different in the source and destination buffers.
190 * So if the DMA engine doesn't copy exactly what we tell it to copy,
191 * we'll notice.
192 */
dmatest_func(void * data)193 static int dmatest_func(void *data)
194 {
195 struct dmatest_thread *thread = data;
196 struct dma_chan *chan;
197 const char *thread_name;
198 unsigned int src_off, dst_off, len;
199 unsigned int error_count;
200 unsigned int failed_tests = 0;
201 unsigned int total_tests = 0;
202 dma_cookie_t cookie;
203 enum dma_status status;
204 int ret;
205
206 thread_name = current->comm;
207
208 ret = -ENOMEM;
209 thread->srcbuf = kmalloc(test_buf_size, GFP_KERNEL);
210 if (!thread->srcbuf)
211 goto err_srcbuf;
212 thread->dstbuf = kmalloc(test_buf_size, GFP_KERNEL);
213 if (!thread->dstbuf)
214 goto err_dstbuf;
215
216 smp_rmb();
217 chan = thread->chan;
218
219 while (!kthread_should_stop()) {
220 struct dma_device *dev = chan->device;
221 struct dma_async_tx_descriptor *tx;
222 dma_addr_t dma_src, dma_dest;
223
224 total_tests++;
225
226 len = dmatest_random() % test_buf_size + 1;
227 src_off = dmatest_random() % (test_buf_size - len + 1);
228 dst_off = dmatest_random() % (test_buf_size - len + 1);
229
230 dmatest_init_srcbuf(thread->srcbuf, src_off, len);
231 dmatest_init_dstbuf(thread->dstbuf, dst_off, len);
232
233 dma_src = dma_map_single(dev->dev, thread->srcbuf + src_off,
234 len, DMA_TO_DEVICE);
235 /* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
236 dma_dest = dma_map_single(dev->dev, thread->dstbuf,
237 test_buf_size, DMA_BIDIRECTIONAL);
238
239 tx = dev->device_prep_dma_memcpy(chan, dma_dest + dst_off,
240 dma_src, len,
241 DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP);
242 if (!tx) {
243 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
244 dma_unmap_single(dev->dev, dma_dest,
245 test_buf_size, DMA_BIDIRECTIONAL);
246 pr_warning("%s: #%u: prep error with src_off=0x%x "
247 "dst_off=0x%x len=0x%x\n",
248 thread_name, total_tests - 1,
249 src_off, dst_off, len);
250 msleep(100);
251 failed_tests++;
252 continue;
253 }
254 tx->callback = NULL;
255 cookie = tx->tx_submit(tx);
256
257 if (dma_submit_error(cookie)) {
258 pr_warning("%s: #%u: submit error %d with src_off=0x%x "
259 "dst_off=0x%x len=0x%x\n",
260 thread_name, total_tests - 1, cookie,
261 src_off, dst_off, len);
262 msleep(100);
263 failed_tests++;
264 continue;
265 }
266 dma_async_memcpy_issue_pending(chan);
267
268 do {
269 msleep(1);
270 status = dma_async_memcpy_complete(
271 chan, cookie, NULL, NULL);
272 } while (status == DMA_IN_PROGRESS);
273
274 if (status == DMA_ERROR) {
275 pr_warning("%s: #%u: error during copy\n",
276 thread_name, total_tests - 1);
277 failed_tests++;
278 continue;
279 }
280 /* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
281 dma_unmap_single(dev->dev, dma_dest,
282 test_buf_size, DMA_BIDIRECTIONAL);
283
284 error_count = 0;
285
286 pr_debug("%s: verifying source buffer...\n", thread_name);
287 error_count += dmatest_verify(thread->srcbuf, 0, src_off,
288 0, PATTERN_SRC, true);
289 error_count += dmatest_verify(thread->srcbuf, src_off,
290 src_off + len, src_off,
291 PATTERN_SRC | PATTERN_COPY, true);
292 error_count += dmatest_verify(thread->srcbuf, src_off + len,
293 test_buf_size, src_off + len,
294 PATTERN_SRC, true);
295
296 pr_debug("%s: verifying dest buffer...\n",
297 thread->task->comm);
298 error_count += dmatest_verify(thread->dstbuf, 0, dst_off,
299 0, PATTERN_DST, false);
300 error_count += dmatest_verify(thread->dstbuf, dst_off,
301 dst_off + len, src_off,
302 PATTERN_SRC | PATTERN_COPY, false);
303 error_count += dmatest_verify(thread->dstbuf, dst_off + len,
304 test_buf_size, dst_off + len,
305 PATTERN_DST, false);
306
307 if (error_count) {
308 pr_warning("%s: #%u: %u errors with "
309 "src_off=0x%x dst_off=0x%x len=0x%x\n",
310 thread_name, total_tests - 1, error_count,
311 src_off, dst_off, len);
312 failed_tests++;
313 } else {
314 pr_debug("%s: #%u: No errors with "
315 "src_off=0x%x dst_off=0x%x len=0x%x\n",
316 thread_name, total_tests - 1,
317 src_off, dst_off, len);
318 }
319 }
320
321 ret = 0;
322 kfree(thread->dstbuf);
323 err_dstbuf:
324 kfree(thread->srcbuf);
325 err_srcbuf:
326 pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",
327 thread_name, total_tests, failed_tests, ret);
328 return ret;
329 }
330
dmatest_cleanup_channel(struct dmatest_chan * dtc)331 static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
332 {
333 struct dmatest_thread *thread;
334 struct dmatest_thread *_thread;
335 int ret;
336
337 list_for_each_entry_safe(thread, _thread, &dtc->threads, node) {
338 ret = kthread_stop(thread->task);
339 pr_debug("dmatest: thread %s exited with status %d\n",
340 thread->task->comm, ret);
341 list_del(&thread->node);
342 kfree(thread);
343 }
344 kfree(dtc);
345 }
346
dmatest_add_channel(struct dma_chan * chan)347 static int dmatest_add_channel(struct dma_chan *chan)
348 {
349 struct dmatest_chan *dtc;
350 struct dmatest_thread *thread;
351 unsigned int i;
352
353 dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
354 if (!dtc) {
355 pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));
356 return -ENOMEM;
357 }
358
359 dtc->chan = chan;
360 INIT_LIST_HEAD(&dtc->threads);
361
362 for (i = 0; i < threads_per_chan; i++) {
363 thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
364 if (!thread) {
365 pr_warning("dmatest: No memory for %s-test%u\n",
366 dma_chan_name(chan), i);
367 break;
368 }
369 thread->chan = dtc->chan;
370 smp_wmb();
371 thread->task = kthread_run(dmatest_func, thread, "%s-test%u",
372 dma_chan_name(chan), i);
373 if (IS_ERR(thread->task)) {
374 pr_warning("dmatest: Failed to run thread %s-test%u\n",
375 dma_chan_name(chan), i);
376 kfree(thread);
377 break;
378 }
379
380 /* srcbuf and dstbuf are allocated by the thread itself */
381
382 list_add_tail(&thread->node, &dtc->threads);
383 }
384
385 pr_info("dmatest: Started %u threads using %s\n", i, dma_chan_name(chan));
386
387 list_add_tail(&dtc->node, &dmatest_channels);
388 nr_channels++;
389
390 return 0;
391 }
392
filter(struct dma_chan * chan,void * param)393 static bool filter(struct dma_chan *chan, void *param)
394 {
395 if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device))
396 return false;
397 else
398 return true;
399 }
400
dmatest_init(void)401 static int __init dmatest_init(void)
402 {
403 dma_cap_mask_t mask;
404 struct dma_chan *chan;
405 int err = 0;
406
407 dma_cap_zero(mask);
408 dma_cap_set(DMA_MEMCPY, mask);
409 for (;;) {
410 chan = dma_request_channel(mask, filter, NULL);
411 if (chan) {
412 err = dmatest_add_channel(chan);
413 if (err == 0)
414 continue;
415 else {
416 dma_release_channel(chan);
417 break; /* add_channel failed, punt */
418 }
419 } else
420 break; /* no more channels available */
421 if (max_channels && nr_channels >= max_channels)
422 break; /* we have all we need */
423 }
424
425 return err;
426 }
427 /* when compiled-in wait for drivers to load first */
428 late_initcall(dmatest_init);
429
dmatest_exit(void)430 static void __exit dmatest_exit(void)
431 {
432 struct dmatest_chan *dtc, *_dtc;
433 struct dma_chan *chan;
434
435 list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
436 list_del(&dtc->node);
437 chan = dtc->chan;
438 dmatest_cleanup_channel(dtc);
439 pr_debug("dmatest: dropped channel %s\n",
440 dma_chan_name(chan));
441 dma_release_channel(chan);
442 }
443 }
444 module_exit(dmatest_exit);
445
446 MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
447 MODULE_LICENSE("GPL v2");
448