Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
[linux-2.6] / drivers / dma / dmatest.c
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
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
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
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
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
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
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
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  */
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
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
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
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
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
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");