xref: /openbmc/linux/drivers/dma/dmatest.c (revision afc98d90)
1 /*
2  * DMA Engine test module
3  *
4  * Copyright (C) 2007 Atmel Corporation
5  * Copyright (C) 2013 Intel Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/delay.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/dmaengine.h>
16 #include <linux/freezer.h>
17 #include <linux/init.h>
18 #include <linux/kthread.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/random.h>
22 #include <linux/slab.h>
23 #include <linux/wait.h>
24 
25 static unsigned int test_buf_size = 16384;
26 module_param(test_buf_size, uint, S_IRUGO | S_IWUSR);
27 MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer");
28 
29 static char test_channel[20];
30 module_param_string(channel, test_channel, sizeof(test_channel),
31 		S_IRUGO | S_IWUSR);
32 MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
33 
34 static char test_device[32];
35 module_param_string(device, test_device, sizeof(test_device),
36 		S_IRUGO | S_IWUSR);
37 MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)");
38 
39 static unsigned int threads_per_chan = 1;
40 module_param(threads_per_chan, uint, S_IRUGO | S_IWUSR);
41 MODULE_PARM_DESC(threads_per_chan,
42 		"Number of threads to start per channel (default: 1)");
43 
44 static unsigned int max_channels;
45 module_param(max_channels, uint, S_IRUGO | S_IWUSR);
46 MODULE_PARM_DESC(max_channels,
47 		"Maximum number of channels to use (default: all)");
48 
49 static unsigned int iterations;
50 module_param(iterations, uint, S_IRUGO | S_IWUSR);
51 MODULE_PARM_DESC(iterations,
52 		"Iterations before stopping test (default: infinite)");
53 
54 static unsigned int xor_sources = 3;
55 module_param(xor_sources, uint, S_IRUGO | S_IWUSR);
56 MODULE_PARM_DESC(xor_sources,
57 		"Number of xor source buffers (default: 3)");
58 
59 static unsigned int pq_sources = 3;
60 module_param(pq_sources, uint, S_IRUGO | S_IWUSR);
61 MODULE_PARM_DESC(pq_sources,
62 		"Number of p+q source buffers (default: 3)");
63 
64 static int timeout = 3000;
65 module_param(timeout, uint, S_IRUGO | S_IWUSR);
66 MODULE_PARM_DESC(timeout, "Transfer Timeout in msec (default: 3000), "
67 		 "Pass -1 for infinite timeout");
68 
69 static bool noverify;
70 module_param(noverify, bool, S_IRUGO | S_IWUSR);
71 MODULE_PARM_DESC(noverify, "Disable random data setup and verification");
72 
73 static bool verbose;
74 module_param(verbose, bool, S_IRUGO | S_IWUSR);
75 MODULE_PARM_DESC(verbose, "Enable \"success\" result messages (default: off)");
76 
77 /**
78  * struct dmatest_params - test parameters.
79  * @buf_size:		size of the memcpy test buffer
80  * @channel:		bus ID of the channel to test
81  * @device:		bus ID of the DMA Engine to test
82  * @threads_per_chan:	number of threads to start per channel
83  * @max_channels:	maximum number of channels to use
84  * @iterations:		iterations before stopping test
85  * @xor_sources:	number of xor source buffers
86  * @pq_sources:		number of p+q source buffers
87  * @timeout:		transfer timeout in msec, -1 for infinite timeout
88  */
89 struct dmatest_params {
90 	unsigned int	buf_size;
91 	char		channel[20];
92 	char		device[32];
93 	unsigned int	threads_per_chan;
94 	unsigned int	max_channels;
95 	unsigned int	iterations;
96 	unsigned int	xor_sources;
97 	unsigned int	pq_sources;
98 	int		timeout;
99 	bool		noverify;
100 };
101 
102 /**
103  * struct dmatest_info - test information.
104  * @params:		test parameters
105  * @lock:		access protection to the fields of this structure
106  */
107 static struct dmatest_info {
108 	/* Test parameters */
109 	struct dmatest_params	params;
110 
111 	/* Internal state */
112 	struct list_head	channels;
113 	unsigned int		nr_channels;
114 	struct mutex		lock;
115 	bool			did_init;
116 } test_info = {
117 	.channels = LIST_HEAD_INIT(test_info.channels),
118 	.lock = __MUTEX_INITIALIZER(test_info.lock),
119 };
120 
121 static int dmatest_run_set(const char *val, const struct kernel_param *kp);
122 static int dmatest_run_get(char *val, const struct kernel_param *kp);
123 static struct kernel_param_ops run_ops = {
124 	.set = dmatest_run_set,
125 	.get = dmatest_run_get,
126 };
127 static bool dmatest_run;
128 module_param_cb(run, &run_ops, &dmatest_run, S_IRUGO | S_IWUSR);
129 MODULE_PARM_DESC(run, "Run the test (default: false)");
130 
131 /* Maximum amount of mismatched bytes in buffer to print */
132 #define MAX_ERROR_COUNT		32
133 
134 /*
135  * Initialization patterns. All bytes in the source buffer has bit 7
136  * set, all bytes in the destination buffer has bit 7 cleared.
137  *
138  * Bit 6 is set for all bytes which are to be copied by the DMA
139  * engine. Bit 5 is set for all bytes which are to be overwritten by
140  * the DMA engine.
141  *
142  * The remaining bits are the inverse of a counter which increments by
143  * one for each byte address.
144  */
145 #define PATTERN_SRC		0x80
146 #define PATTERN_DST		0x00
147 #define PATTERN_COPY		0x40
148 #define PATTERN_OVERWRITE	0x20
149 #define PATTERN_COUNT_MASK	0x1f
150 
151 struct dmatest_thread {
152 	struct list_head	node;
153 	struct dmatest_info	*info;
154 	struct task_struct	*task;
155 	struct dma_chan		*chan;
156 	u8			**srcs;
157 	u8			**dsts;
158 	enum dma_transaction_type type;
159 	bool			done;
160 };
161 
162 struct dmatest_chan {
163 	struct list_head	node;
164 	struct dma_chan		*chan;
165 	struct list_head	threads;
166 };
167 
168 static DECLARE_WAIT_QUEUE_HEAD(thread_wait);
169 static bool wait;
170 
171 static bool is_threaded_test_run(struct dmatest_info *info)
172 {
173 	struct dmatest_chan *dtc;
174 
175 	list_for_each_entry(dtc, &info->channels, node) {
176 		struct dmatest_thread *thread;
177 
178 		list_for_each_entry(thread, &dtc->threads, node) {
179 			if (!thread->done)
180 				return true;
181 		}
182 	}
183 
184 	return false;
185 }
186 
187 static int dmatest_wait_get(char *val, const struct kernel_param *kp)
188 {
189 	struct dmatest_info *info = &test_info;
190 	struct dmatest_params *params = &info->params;
191 
192 	if (params->iterations)
193 		wait_event(thread_wait, !is_threaded_test_run(info));
194 	wait = true;
195 	return param_get_bool(val, kp);
196 }
197 
198 static struct kernel_param_ops wait_ops = {
199 	.get = dmatest_wait_get,
200 	.set = param_set_bool,
201 };
202 module_param_cb(wait, &wait_ops, &wait, S_IRUGO);
203 MODULE_PARM_DESC(wait, "Wait for tests to complete (default: false)");
204 
205 static bool dmatest_match_channel(struct dmatest_params *params,
206 		struct dma_chan *chan)
207 {
208 	if (params->channel[0] == '\0')
209 		return true;
210 	return strcmp(dma_chan_name(chan), params->channel) == 0;
211 }
212 
213 static bool dmatest_match_device(struct dmatest_params *params,
214 		struct dma_device *device)
215 {
216 	if (params->device[0] == '\0')
217 		return true;
218 	return strcmp(dev_name(device->dev), params->device) == 0;
219 }
220 
221 static unsigned long dmatest_random(void)
222 {
223 	unsigned long buf;
224 
225 	prandom_bytes(&buf, sizeof(buf));
226 	return buf;
227 }
228 
229 static void dmatest_init_srcs(u8 **bufs, unsigned int start, unsigned int len,
230 		unsigned int buf_size)
231 {
232 	unsigned int i;
233 	u8 *buf;
234 
235 	for (; (buf = *bufs); bufs++) {
236 		for (i = 0; i < start; i++)
237 			buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
238 		for ( ; i < start + len; i++)
239 			buf[i] = PATTERN_SRC | PATTERN_COPY
240 				| (~i & PATTERN_COUNT_MASK);
241 		for ( ; i < buf_size; i++)
242 			buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
243 		buf++;
244 	}
245 }
246 
247 static void dmatest_init_dsts(u8 **bufs, unsigned int start, unsigned int len,
248 		unsigned int buf_size)
249 {
250 	unsigned int i;
251 	u8 *buf;
252 
253 	for (; (buf = *bufs); bufs++) {
254 		for (i = 0; i < start; i++)
255 			buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
256 		for ( ; i < start + len; i++)
257 			buf[i] = PATTERN_DST | PATTERN_OVERWRITE
258 				| (~i & PATTERN_COUNT_MASK);
259 		for ( ; i < buf_size; i++)
260 			buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
261 	}
262 }
263 
264 static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
265 		unsigned int counter, bool is_srcbuf)
266 {
267 	u8		diff = actual ^ pattern;
268 	u8		expected = pattern | (~counter & PATTERN_COUNT_MASK);
269 	const char	*thread_name = current->comm;
270 
271 	if (is_srcbuf)
272 		pr_warn("%s: srcbuf[0x%x] overwritten! Expected %02x, got %02x\n",
273 			thread_name, index, expected, actual);
274 	else if ((pattern & PATTERN_COPY)
275 			&& (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
276 		pr_warn("%s: dstbuf[0x%x] not copied! Expected %02x, got %02x\n",
277 			thread_name, index, expected, actual);
278 	else if (diff & PATTERN_SRC)
279 		pr_warn("%s: dstbuf[0x%x] was copied! Expected %02x, got %02x\n",
280 			thread_name, index, expected, actual);
281 	else
282 		pr_warn("%s: dstbuf[0x%x] mismatch! Expected %02x, got %02x\n",
283 			thread_name, index, expected, actual);
284 }
285 
286 static unsigned int dmatest_verify(u8 **bufs, unsigned int start,
287 		unsigned int end, unsigned int counter, u8 pattern,
288 		bool is_srcbuf)
289 {
290 	unsigned int i;
291 	unsigned int error_count = 0;
292 	u8 actual;
293 	u8 expected;
294 	u8 *buf;
295 	unsigned int counter_orig = counter;
296 
297 	for (; (buf = *bufs); bufs++) {
298 		counter = counter_orig;
299 		for (i = start; i < end; i++) {
300 			actual = buf[i];
301 			expected = pattern | (~counter & PATTERN_COUNT_MASK);
302 			if (actual != expected) {
303 				if (error_count < MAX_ERROR_COUNT)
304 					dmatest_mismatch(actual, pattern, i,
305 							 counter, is_srcbuf);
306 				error_count++;
307 			}
308 			counter++;
309 		}
310 	}
311 
312 	if (error_count > MAX_ERROR_COUNT)
313 		pr_warn("%s: %u errors suppressed\n",
314 			current->comm, error_count - MAX_ERROR_COUNT);
315 
316 	return error_count;
317 }
318 
319 /* poor man's completion - we want to use wait_event_freezable() on it */
320 struct dmatest_done {
321 	bool			done;
322 	wait_queue_head_t	*wait;
323 };
324 
325 static void dmatest_callback(void *arg)
326 {
327 	struct dmatest_done *done = arg;
328 
329 	done->done = true;
330 	wake_up_all(done->wait);
331 }
332 
333 static unsigned int min_odd(unsigned int x, unsigned int y)
334 {
335 	unsigned int val = min(x, y);
336 
337 	return val % 2 ? val : val - 1;
338 }
339 
340 static void result(const char *err, unsigned int n, unsigned int src_off,
341 		   unsigned int dst_off, unsigned int len, unsigned long data)
342 {
343 	pr_info("%s: result #%u: '%s' with src_off=0x%x dst_off=0x%x len=0x%x (%lu)",
344 		current->comm, n, err, src_off, dst_off, len, data);
345 }
346 
347 static void dbg_result(const char *err, unsigned int n, unsigned int src_off,
348 		       unsigned int dst_off, unsigned int len,
349 		       unsigned long data)
350 {
351 	pr_debug("%s: result #%u: '%s' with src_off=0x%x dst_off=0x%x len=0x%x (%lu)",
352 		   current->comm, n, err, src_off, dst_off, len, data);
353 }
354 
355 #define verbose_result(err, n, src_off, dst_off, len, data) ({ \
356 	if (verbose) \
357 		result(err, n, src_off, dst_off, len, data); \
358 	else \
359 		dbg_result(err, n, src_off, dst_off, len, data); \
360 })
361 
362 static unsigned long long dmatest_persec(s64 runtime, unsigned int val)
363 {
364 	unsigned long long per_sec = 1000000;
365 
366 	if (runtime <= 0)
367 		return 0;
368 
369 	/* drop precision until runtime is 32-bits */
370 	while (runtime > UINT_MAX) {
371 		runtime >>= 1;
372 		per_sec <<= 1;
373 	}
374 
375 	per_sec *= val;
376 	do_div(per_sec, runtime);
377 	return per_sec;
378 }
379 
380 static unsigned long long dmatest_KBs(s64 runtime, unsigned long long len)
381 {
382 	return dmatest_persec(runtime, len >> 10);
383 }
384 
385 /*
386  * This function repeatedly tests DMA transfers of various lengths and
387  * offsets for a given operation type until it is told to exit by
388  * kthread_stop(). There may be multiple threads running this function
389  * in parallel for a single channel, and there may be multiple channels
390  * being tested in parallel.
391  *
392  * Before each test, the source and destination buffer is initialized
393  * with a known pattern. This pattern is different depending on
394  * whether it's in an area which is supposed to be copied or
395  * overwritten, and different in the source and destination buffers.
396  * So if the DMA engine doesn't copy exactly what we tell it to copy,
397  * we'll notice.
398  */
399 static int dmatest_func(void *data)
400 {
401 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(done_wait);
402 	struct dmatest_thread	*thread = data;
403 	struct dmatest_done	done = { .wait = &done_wait };
404 	struct dmatest_info	*info;
405 	struct dmatest_params	*params;
406 	struct dma_chan		*chan;
407 	struct dma_device	*dev;
408 	unsigned int		src_off, dst_off, len;
409 	unsigned int		error_count;
410 	unsigned int		failed_tests = 0;
411 	unsigned int		total_tests = 0;
412 	dma_cookie_t		cookie;
413 	enum dma_status		status;
414 	enum dma_ctrl_flags 	flags;
415 	u8			*pq_coefs = NULL;
416 	int			ret;
417 	int			src_cnt;
418 	int			dst_cnt;
419 	int			i;
420 	ktime_t			ktime;
421 	s64			runtime = 0;
422 	unsigned long long	total_len = 0;
423 
424 	set_freezable();
425 
426 	ret = -ENOMEM;
427 
428 	smp_rmb();
429 	info = thread->info;
430 	params = &info->params;
431 	chan = thread->chan;
432 	dev = chan->device;
433 	if (thread->type == DMA_MEMCPY)
434 		src_cnt = dst_cnt = 1;
435 	else if (thread->type == DMA_XOR) {
436 		/* force odd to ensure dst = src */
437 		src_cnt = min_odd(params->xor_sources | 1, dev->max_xor);
438 		dst_cnt = 1;
439 	} else if (thread->type == DMA_PQ) {
440 		/* force odd to ensure dst = src */
441 		src_cnt = min_odd(params->pq_sources | 1, dma_maxpq(dev, 0));
442 		dst_cnt = 2;
443 
444 		pq_coefs = kmalloc(params->pq_sources+1, GFP_KERNEL);
445 		if (!pq_coefs)
446 			goto err_thread_type;
447 
448 		for (i = 0; i < src_cnt; i++)
449 			pq_coefs[i] = 1;
450 	} else
451 		goto err_thread_type;
452 
453 	thread->srcs = kcalloc(src_cnt+1, sizeof(u8 *), GFP_KERNEL);
454 	if (!thread->srcs)
455 		goto err_srcs;
456 	for (i = 0; i < src_cnt; i++) {
457 		thread->srcs[i] = kmalloc(params->buf_size, GFP_KERNEL);
458 		if (!thread->srcs[i])
459 			goto err_srcbuf;
460 	}
461 	thread->srcs[i] = NULL;
462 
463 	thread->dsts = kcalloc(dst_cnt+1, sizeof(u8 *), GFP_KERNEL);
464 	if (!thread->dsts)
465 		goto err_dsts;
466 	for (i = 0; i < dst_cnt; i++) {
467 		thread->dsts[i] = kmalloc(params->buf_size, GFP_KERNEL);
468 		if (!thread->dsts[i])
469 			goto err_dstbuf;
470 	}
471 	thread->dsts[i] = NULL;
472 
473 	set_user_nice(current, 10);
474 
475 	/*
476 	 * src and dst buffers are freed by ourselves below
477 	 */
478 	flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
479 
480 	ktime = ktime_get();
481 	while (!kthread_should_stop()
482 	       && !(params->iterations && total_tests >= params->iterations)) {
483 		struct dma_async_tx_descriptor *tx = NULL;
484 		struct dmaengine_unmap_data *um;
485 		dma_addr_t srcs[src_cnt];
486 		dma_addr_t *dsts;
487 		u8 align = 0;
488 
489 		total_tests++;
490 
491 		/* honor alignment restrictions */
492 		if (thread->type == DMA_MEMCPY)
493 			align = dev->copy_align;
494 		else if (thread->type == DMA_XOR)
495 			align = dev->xor_align;
496 		else if (thread->type == DMA_PQ)
497 			align = dev->pq_align;
498 
499 		if (1 << align > params->buf_size) {
500 			pr_err("%u-byte buffer too small for %d-byte alignment\n",
501 			       params->buf_size, 1 << align);
502 			break;
503 		}
504 
505 		if (params->noverify) {
506 			len = params->buf_size;
507 			src_off = 0;
508 			dst_off = 0;
509 		} else {
510 			len = dmatest_random() % params->buf_size + 1;
511 			len = (len >> align) << align;
512 			if (!len)
513 				len = 1 << align;
514 			src_off = dmatest_random() % (params->buf_size - len + 1);
515 			dst_off = dmatest_random() % (params->buf_size - len + 1);
516 
517 			src_off = (src_off >> align) << align;
518 			dst_off = (dst_off >> align) << align;
519 
520 			dmatest_init_srcs(thread->srcs, src_off, len,
521 					  params->buf_size);
522 			dmatest_init_dsts(thread->dsts, dst_off, len,
523 					  params->buf_size);
524 		}
525 
526 		len = (len >> align) << align;
527 		if (!len)
528 			len = 1 << align;
529 		total_len += len;
530 
531 		um = dmaengine_get_unmap_data(dev->dev, src_cnt+dst_cnt,
532 					      GFP_KERNEL);
533 		if (!um) {
534 			failed_tests++;
535 			result("unmap data NULL", total_tests,
536 			       src_off, dst_off, len, ret);
537 			continue;
538 		}
539 
540 		um->len = params->buf_size;
541 		for (i = 0; i < src_cnt; i++) {
542 			void *buf = thread->srcs[i];
543 			struct page *pg = virt_to_page(buf);
544 			unsigned pg_off = (unsigned long) buf & ~PAGE_MASK;
545 
546 			um->addr[i] = dma_map_page(dev->dev, pg, pg_off,
547 						   um->len, DMA_TO_DEVICE);
548 			srcs[i] = um->addr[i] + src_off;
549 			ret = dma_mapping_error(dev->dev, um->addr[i]);
550 			if (ret) {
551 				dmaengine_unmap_put(um);
552 				result("src mapping error", total_tests,
553 				       src_off, dst_off, len, ret);
554 				failed_tests++;
555 				continue;
556 			}
557 			um->to_cnt++;
558 		}
559 		/* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
560 		dsts = &um->addr[src_cnt];
561 		for (i = 0; i < dst_cnt; i++) {
562 			void *buf = thread->dsts[i];
563 			struct page *pg = virt_to_page(buf);
564 			unsigned pg_off = (unsigned long) buf & ~PAGE_MASK;
565 
566 			dsts[i] = dma_map_page(dev->dev, pg, pg_off, um->len,
567 					       DMA_BIDIRECTIONAL);
568 			ret = dma_mapping_error(dev->dev, dsts[i]);
569 			if (ret) {
570 				dmaengine_unmap_put(um);
571 				result("dst mapping error", total_tests,
572 				       src_off, dst_off, len, ret);
573 				failed_tests++;
574 				continue;
575 			}
576 			um->bidi_cnt++;
577 		}
578 
579 		if (thread->type == DMA_MEMCPY)
580 			tx = dev->device_prep_dma_memcpy(chan,
581 							 dsts[0] + dst_off,
582 							 srcs[0], len, flags);
583 		else if (thread->type == DMA_XOR)
584 			tx = dev->device_prep_dma_xor(chan,
585 						      dsts[0] + dst_off,
586 						      srcs, src_cnt,
587 						      len, flags);
588 		else if (thread->type == DMA_PQ) {
589 			dma_addr_t dma_pq[dst_cnt];
590 
591 			for (i = 0; i < dst_cnt; i++)
592 				dma_pq[i] = dsts[i] + dst_off;
593 			tx = dev->device_prep_dma_pq(chan, dma_pq, srcs,
594 						     src_cnt, pq_coefs,
595 						     len, flags);
596 		}
597 
598 		if (!tx) {
599 			dmaengine_unmap_put(um);
600 			result("prep error", total_tests, src_off,
601 			       dst_off, len, ret);
602 			msleep(100);
603 			failed_tests++;
604 			continue;
605 		}
606 
607 		done.done = false;
608 		tx->callback = dmatest_callback;
609 		tx->callback_param = &done;
610 		cookie = tx->tx_submit(tx);
611 
612 		if (dma_submit_error(cookie)) {
613 			dmaengine_unmap_put(um);
614 			result("submit error", total_tests, src_off,
615 			       dst_off, len, ret);
616 			msleep(100);
617 			failed_tests++;
618 			continue;
619 		}
620 		dma_async_issue_pending(chan);
621 
622 		wait_event_freezable_timeout(done_wait, done.done,
623 					     msecs_to_jiffies(params->timeout));
624 
625 		status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
626 
627 		if (!done.done) {
628 			/*
629 			 * We're leaving the timed out dma operation with
630 			 * dangling pointer to done_wait.  To make this
631 			 * correct, we'll need to allocate wait_done for
632 			 * each test iteration and perform "who's gonna
633 			 * free it this time?" dancing.  For now, just
634 			 * leave it dangling.
635 			 */
636 			dmaengine_unmap_put(um);
637 			result("test timed out", total_tests, src_off, dst_off,
638 			       len, 0);
639 			failed_tests++;
640 			continue;
641 		} else if (status != DMA_COMPLETE) {
642 			dmaengine_unmap_put(um);
643 			result(status == DMA_ERROR ?
644 			       "completion error status" :
645 			       "completion busy status", total_tests, src_off,
646 			       dst_off, len, ret);
647 			failed_tests++;
648 			continue;
649 		}
650 
651 		dmaengine_unmap_put(um);
652 
653 		if (params->noverify) {
654 			verbose_result("test passed", total_tests, src_off,
655 				       dst_off, len, 0);
656 			continue;
657 		}
658 
659 		pr_debug("%s: verifying source buffer...\n", current->comm);
660 		error_count = dmatest_verify(thread->srcs, 0, src_off,
661 				0, PATTERN_SRC, true);
662 		error_count += dmatest_verify(thread->srcs, src_off,
663 				src_off + len, src_off,
664 				PATTERN_SRC | PATTERN_COPY, true);
665 		error_count += dmatest_verify(thread->srcs, src_off + len,
666 				params->buf_size, src_off + len,
667 				PATTERN_SRC, true);
668 
669 		pr_debug("%s: verifying dest buffer...\n", current->comm);
670 		error_count += dmatest_verify(thread->dsts, 0, dst_off,
671 				0, PATTERN_DST, false);
672 		error_count += dmatest_verify(thread->dsts, dst_off,
673 				dst_off + len, src_off,
674 				PATTERN_SRC | PATTERN_COPY, false);
675 		error_count += dmatest_verify(thread->dsts, dst_off + len,
676 				params->buf_size, dst_off + len,
677 				PATTERN_DST, false);
678 
679 		if (error_count) {
680 			result("data error", total_tests, src_off, dst_off,
681 			       len, error_count);
682 			failed_tests++;
683 		} else {
684 			verbose_result("test passed", total_tests, src_off,
685 				       dst_off, len, 0);
686 		}
687 	}
688 	runtime = ktime_us_delta(ktime_get(), ktime);
689 
690 	ret = 0;
691 	for (i = 0; thread->dsts[i]; i++)
692 		kfree(thread->dsts[i]);
693 err_dstbuf:
694 	kfree(thread->dsts);
695 err_dsts:
696 	for (i = 0; thread->srcs[i]; i++)
697 		kfree(thread->srcs[i]);
698 err_srcbuf:
699 	kfree(thread->srcs);
700 err_srcs:
701 	kfree(pq_coefs);
702 err_thread_type:
703 	pr_info("%s: summary %u tests, %u failures %llu iops %llu KB/s (%d)\n",
704 		current->comm, total_tests, failed_tests,
705 		dmatest_persec(runtime, total_tests),
706 		dmatest_KBs(runtime, total_len), ret);
707 
708 	/* terminate all transfers on specified channels */
709 	if (ret)
710 		dmaengine_terminate_all(chan);
711 
712 	thread->done = true;
713 	wake_up(&thread_wait);
714 
715 	return ret;
716 }
717 
718 static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
719 {
720 	struct dmatest_thread	*thread;
721 	struct dmatest_thread	*_thread;
722 	int			ret;
723 
724 	list_for_each_entry_safe(thread, _thread, &dtc->threads, node) {
725 		ret = kthread_stop(thread->task);
726 		pr_debug("thread %s exited with status %d\n",
727 			 thread->task->comm, ret);
728 		list_del(&thread->node);
729 		put_task_struct(thread->task);
730 		kfree(thread);
731 	}
732 
733 	/* terminate all transfers on specified channels */
734 	dmaengine_terminate_all(dtc->chan);
735 
736 	kfree(dtc);
737 }
738 
739 static int dmatest_add_threads(struct dmatest_info *info,
740 		struct dmatest_chan *dtc, enum dma_transaction_type type)
741 {
742 	struct dmatest_params *params = &info->params;
743 	struct dmatest_thread *thread;
744 	struct dma_chan *chan = dtc->chan;
745 	char *op;
746 	unsigned int i;
747 
748 	if (type == DMA_MEMCPY)
749 		op = "copy";
750 	else if (type == DMA_XOR)
751 		op = "xor";
752 	else if (type == DMA_PQ)
753 		op = "pq";
754 	else
755 		return -EINVAL;
756 
757 	for (i = 0; i < params->threads_per_chan; i++) {
758 		thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
759 		if (!thread) {
760 			pr_warn("No memory for %s-%s%u\n",
761 				dma_chan_name(chan), op, i);
762 			break;
763 		}
764 		thread->info = info;
765 		thread->chan = dtc->chan;
766 		thread->type = type;
767 		smp_wmb();
768 		thread->task = kthread_create(dmatest_func, thread, "%s-%s%u",
769 				dma_chan_name(chan), op, i);
770 		if (IS_ERR(thread->task)) {
771 			pr_warn("Failed to create thread %s-%s%u\n",
772 				dma_chan_name(chan), op, i);
773 			kfree(thread);
774 			break;
775 		}
776 
777 		/* srcbuf and dstbuf are allocated by the thread itself */
778 		get_task_struct(thread->task);
779 		list_add_tail(&thread->node, &dtc->threads);
780 		wake_up_process(thread->task);
781 	}
782 
783 	return i;
784 }
785 
786 static int dmatest_add_channel(struct dmatest_info *info,
787 		struct dma_chan *chan)
788 {
789 	struct dmatest_chan	*dtc;
790 	struct dma_device	*dma_dev = chan->device;
791 	unsigned int		thread_count = 0;
792 	int cnt;
793 
794 	dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
795 	if (!dtc) {
796 		pr_warn("No memory for %s\n", dma_chan_name(chan));
797 		return -ENOMEM;
798 	}
799 
800 	dtc->chan = chan;
801 	INIT_LIST_HEAD(&dtc->threads);
802 
803 	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
804 		cnt = dmatest_add_threads(info, dtc, DMA_MEMCPY);
805 		thread_count += cnt > 0 ? cnt : 0;
806 	}
807 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
808 		cnt = dmatest_add_threads(info, dtc, DMA_XOR);
809 		thread_count += cnt > 0 ? cnt : 0;
810 	}
811 	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
812 		cnt = dmatest_add_threads(info, dtc, DMA_PQ);
813 		thread_count += cnt > 0 ? cnt : 0;
814 	}
815 
816 	pr_info("Started %u threads using %s\n",
817 		thread_count, dma_chan_name(chan));
818 
819 	list_add_tail(&dtc->node, &info->channels);
820 	info->nr_channels++;
821 
822 	return 0;
823 }
824 
825 static bool filter(struct dma_chan *chan, void *param)
826 {
827 	struct dmatest_params *params = param;
828 
829 	if (!dmatest_match_channel(params, chan) ||
830 	    !dmatest_match_device(params, chan->device))
831 		return false;
832 	else
833 		return true;
834 }
835 
836 static void request_channels(struct dmatest_info *info,
837 			     enum dma_transaction_type type)
838 {
839 	dma_cap_mask_t mask;
840 
841 	dma_cap_zero(mask);
842 	dma_cap_set(type, mask);
843 	for (;;) {
844 		struct dmatest_params *params = &info->params;
845 		struct dma_chan *chan;
846 
847 		chan = dma_request_channel(mask, filter, params);
848 		if (chan) {
849 			if (dmatest_add_channel(info, chan)) {
850 				dma_release_channel(chan);
851 				break; /* add_channel failed, punt */
852 			}
853 		} else
854 			break; /* no more channels available */
855 		if (params->max_channels &&
856 		    info->nr_channels >= params->max_channels)
857 			break; /* we have all we need */
858 	}
859 }
860 
861 static void run_threaded_test(struct dmatest_info *info)
862 {
863 	struct dmatest_params *params = &info->params;
864 
865 	/* Copy test parameters */
866 	params->buf_size = test_buf_size;
867 	strlcpy(params->channel, strim(test_channel), sizeof(params->channel));
868 	strlcpy(params->device, strim(test_device), sizeof(params->device));
869 	params->threads_per_chan = threads_per_chan;
870 	params->max_channels = max_channels;
871 	params->iterations = iterations;
872 	params->xor_sources = xor_sources;
873 	params->pq_sources = pq_sources;
874 	params->timeout = timeout;
875 	params->noverify = noverify;
876 
877 	request_channels(info, DMA_MEMCPY);
878 	request_channels(info, DMA_XOR);
879 	request_channels(info, DMA_PQ);
880 }
881 
882 static void stop_threaded_test(struct dmatest_info *info)
883 {
884 	struct dmatest_chan *dtc, *_dtc;
885 	struct dma_chan *chan;
886 
887 	list_for_each_entry_safe(dtc, _dtc, &info->channels, node) {
888 		list_del(&dtc->node);
889 		chan = dtc->chan;
890 		dmatest_cleanup_channel(dtc);
891 		pr_debug("dropped channel %s\n", dma_chan_name(chan));
892 		dma_release_channel(chan);
893 	}
894 
895 	info->nr_channels = 0;
896 }
897 
898 static void restart_threaded_test(struct dmatest_info *info, bool run)
899 {
900 	/* we might be called early to set run=, defer running until all
901 	 * parameters have been evaluated
902 	 */
903 	if (!info->did_init)
904 		return;
905 
906 	/* Stop any running test first */
907 	stop_threaded_test(info);
908 
909 	/* Run test with new parameters */
910 	run_threaded_test(info);
911 }
912 
913 static int dmatest_run_get(char *val, const struct kernel_param *kp)
914 {
915 	struct dmatest_info *info = &test_info;
916 
917 	mutex_lock(&info->lock);
918 	if (is_threaded_test_run(info)) {
919 		dmatest_run = true;
920 	} else {
921 		stop_threaded_test(info);
922 		dmatest_run = false;
923 	}
924 	mutex_unlock(&info->lock);
925 
926 	return param_get_bool(val, kp);
927 }
928 
929 static int dmatest_run_set(const char *val, const struct kernel_param *kp)
930 {
931 	struct dmatest_info *info = &test_info;
932 	int ret;
933 
934 	mutex_lock(&info->lock);
935 	ret = param_set_bool(val, kp);
936 	if (ret) {
937 		mutex_unlock(&info->lock);
938 		return ret;
939 	}
940 
941 	if (is_threaded_test_run(info))
942 		ret = -EBUSY;
943 	else if (dmatest_run)
944 		restart_threaded_test(info, dmatest_run);
945 
946 	mutex_unlock(&info->lock);
947 
948 	return ret;
949 }
950 
951 static int __init dmatest_init(void)
952 {
953 	struct dmatest_info *info = &test_info;
954 	struct dmatest_params *params = &info->params;
955 
956 	if (dmatest_run) {
957 		mutex_lock(&info->lock);
958 		run_threaded_test(info);
959 		mutex_unlock(&info->lock);
960 	}
961 
962 	if (params->iterations && wait)
963 		wait_event(thread_wait, !is_threaded_test_run(info));
964 
965 	/* module parameters are stable, inittime tests are started,
966 	 * let userspace take over 'run' control
967 	 */
968 	info->did_init = true;
969 
970 	return 0;
971 }
972 /* when compiled-in wait for drivers to load first */
973 late_initcall(dmatest_init);
974 
975 static void __exit dmatest_exit(void)
976 {
977 	struct dmatest_info *info = &test_info;
978 
979 	mutex_lock(&info->lock);
980 	stop_threaded_test(info);
981 	mutex_unlock(&info->lock);
982 }
983 module_exit(dmatest_exit);
984 
985 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
986 MODULE_LICENSE("GPL v2");
987