2 * DMA Engine test module
4 * Copyright (C) 2007 Atmel Corporation
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.
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>
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");
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)");
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)");
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)");
36 static unsigned int max_channels;
37 module_param(max_channels, uint, S_IRUGO);
38 MODULE_PARM_DESC(nr_channels,
39 "Maximum number of channels to use (default: all)");
42 * Initialization patterns. All bytes in the source buffer has bit 7
43 * set, all bytes in the destination buffer has bit 7 cleared.
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
49 * The remaining bits are the inverse of a counter which increments by
50 * one for each byte address.
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
58 struct dmatest_thread {
59 struct list_head node;
60 struct task_struct *task;
61 struct dma_chan *chan;
67 struct list_head node;
68 struct dma_chan *chan;
69 struct list_head threads;
73 * These are protected by dma_list_mutex since they're only used by
74 * the DMA client event callback
76 static LIST_HEAD(dmatest_channels);
77 static unsigned int nr_channels;
79 static bool dmatest_match_channel(struct dma_chan *chan)
81 if (test_channel[0] == '\0')
83 return strcmp(dev_name(&chan->dev), test_channel) == 0;
86 static bool dmatest_match_device(struct dma_device *device)
88 if (test_device[0] == '\0')
90 return strcmp(dev_name(device->dev), test_device) == 0;
93 static unsigned long dmatest_random(void)
97 get_random_bytes(&buf, sizeof(buf));
101 static void dmatest_init_srcbuf(u8 *buf, unsigned int start, unsigned int len)
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);
114 static void dmatest_init_dstbuf(u8 *buf, unsigned int start, unsigned int len)
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);
127 static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
128 unsigned int counter, bool is_srcbuf)
130 u8 diff = actual ^ pattern;
131 u8 expected = pattern | (~counter & PATTERN_COUNT_MASK);
132 const char *thread_name = current->comm;
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);
148 pr_warning("%s: dstbuf[0x%x] mismatch!"
149 " Expected %02x, got %02x\n",
150 thread_name, index, expected, actual);
153 static unsigned int dmatest_verify(u8 *buf, unsigned int start,
154 unsigned int end, unsigned int counter, u8 pattern,
158 unsigned int error_count = 0;
161 for (i = start; i < end; i++) {
163 if (actual != (pattern | (~counter & PATTERN_COUNT_MASK))) {
164 if (error_count < 32)
165 dmatest_mismatch(actual, pattern, i, counter,
172 if (error_count > 32)
173 pr_warning("%s: %u errors suppressed\n",
174 current->comm, error_count - 32);
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
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,
193 static int dmatest_func(void *data)
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;
203 enum dma_status status;
206 thread_name = current->comm;
209 thread->srcbuf = kmalloc(test_buf_size, GFP_KERNEL);
212 thread->dstbuf = kmalloc(test_buf_size, GFP_KERNEL);
219 while (!kthread_should_stop()) {
222 len = dmatest_random() % test_buf_size + 1;
223 src_off = dmatest_random() % (test_buf_size - len + 1);
224 dst_off = dmatest_random() % (test_buf_size - len + 1);
226 dmatest_init_srcbuf(thread->srcbuf, src_off, len);
227 dmatest_init_dstbuf(thread->dstbuf, dst_off, len);
229 cookie = dma_async_memcpy_buf_to_buf(chan,
230 thread->dstbuf + dst_off,
231 thread->srcbuf + src_off,
233 if (dma_submit_error(cookie)) {
234 pr_warning("%s: #%u: submit error %d with src_off=0x%x "
235 "dst_off=0x%x len=0x%x\n",
236 thread_name, total_tests - 1, cookie,
237 src_off, dst_off, len);
242 dma_async_memcpy_issue_pending(chan);
246 status = dma_async_memcpy_complete(
247 chan, cookie, NULL, NULL);
248 } while (status == DMA_IN_PROGRESS);
250 if (status == DMA_ERROR) {
251 pr_warning("%s: #%u: error during copy\n",
252 thread_name, total_tests - 1);
259 pr_debug("%s: verifying source buffer...\n", thread_name);
260 error_count += dmatest_verify(thread->srcbuf, 0, src_off,
261 0, PATTERN_SRC, true);
262 error_count += dmatest_verify(thread->srcbuf, src_off,
263 src_off + len, src_off,
264 PATTERN_SRC | PATTERN_COPY, true);
265 error_count += dmatest_verify(thread->srcbuf, src_off + len,
266 test_buf_size, src_off + len,
269 pr_debug("%s: verifying dest buffer...\n",
271 error_count += dmatest_verify(thread->dstbuf, 0, dst_off,
272 0, PATTERN_DST, false);
273 error_count += dmatest_verify(thread->dstbuf, dst_off,
274 dst_off + len, src_off,
275 PATTERN_SRC | PATTERN_COPY, false);
276 error_count += dmatest_verify(thread->dstbuf, dst_off + len,
277 test_buf_size, dst_off + len,
281 pr_warning("%s: #%u: %u errors with "
282 "src_off=0x%x dst_off=0x%x len=0x%x\n",
283 thread_name, total_tests - 1, error_count,
284 src_off, dst_off, len);
287 pr_debug("%s: #%u: No errors with "
288 "src_off=0x%x dst_off=0x%x len=0x%x\n",
289 thread_name, total_tests - 1,
290 src_off, dst_off, len);
295 kfree(thread->dstbuf);
297 kfree(thread->srcbuf);
299 pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",
300 thread_name, total_tests, failed_tests, ret);
304 static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
306 struct dmatest_thread *thread;
307 struct dmatest_thread *_thread;
310 list_for_each_entry_safe(thread, _thread, &dtc->threads, node) {
311 ret = kthread_stop(thread->task);
312 pr_debug("dmatest: thread %s exited with status %d\n",
313 thread->task->comm, ret);
314 list_del(&thread->node);
320 static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
322 struct dmatest_chan *dtc;
323 struct dmatest_thread *thread;
326 /* Have we already been told about this channel? */
327 list_for_each_entry(dtc, &dmatest_channels, node)
328 if (dtc->chan == chan)
331 dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
333 pr_warning("dmatest: No memory for %s\n", dev_name(&chan->dev));
338 INIT_LIST_HEAD(&dtc->threads);
340 for (i = 0; i < threads_per_chan; i++) {
341 thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
343 pr_warning("dmatest: No memory for %s-test%u\n",
344 dev_name(&chan->dev), i);
347 thread->chan = dtc->chan;
349 thread->task = kthread_run(dmatest_func, thread, "%s-test%u",
350 dev_name(&chan->dev), i);
351 if (IS_ERR(thread->task)) {
352 pr_warning("dmatest: Failed to run thread %s-test%u\n",
353 dev_name(&chan->dev), i);
358 /* srcbuf and dstbuf are allocated by the thread itself */
360 list_add_tail(&thread->node, &dtc->threads);
363 pr_info("dmatest: Started %u threads using %s\n", i, dev_name(&chan->dev));
365 list_add_tail(&dtc->node, &dmatest_channels);
371 static enum dma_state_client dmatest_remove_channel(struct dma_chan *chan)
373 struct dmatest_chan *dtc, *_dtc;
375 list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
376 if (dtc->chan == chan) {
377 list_del(&dtc->node);
378 dmatest_cleanup_channel(dtc);
379 pr_debug("dmatest: lost channel %s\n",
380 dev_name(&chan->dev));
389 * Start testing threads as new channels are assigned to us, and kill
390 * them when the channels go away.
392 * When we unregister the client, all channels are removed so this
393 * will also take care of cleaning things up when the module is
396 static enum dma_state_client
397 dmatest_event(struct dma_client *client, struct dma_chan *chan,
398 enum dma_state state)
400 enum dma_state_client ack = DMA_NAK;
403 case DMA_RESOURCE_AVAILABLE:
404 if (!dmatest_match_channel(chan)
405 || !dmatest_match_device(chan->device))
407 else if (max_channels && nr_channels >= max_channels)
410 ack = dmatest_add_channel(chan);
413 case DMA_RESOURCE_REMOVED:
414 ack = dmatest_remove_channel(chan);
418 pr_info("dmatest: Unhandled event %u (%s)\n",
419 state, dev_name(&chan->dev));
426 static struct dma_client dmatest_client = {
427 .event_callback = dmatest_event,
430 static int __init dmatest_init(void)
432 dma_cap_set(DMA_MEMCPY, dmatest_client.cap_mask);
433 dma_async_client_register(&dmatest_client);
434 dma_async_client_chan_request(&dmatest_client);
438 module_init(dmatest_init);
440 static void __exit dmatest_exit(void)
442 dma_async_client_unregister(&dmatest_client);
444 module_exit(dmatest_exit);
446 MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
447 MODULE_LICENSE("GPL v2");