1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * DMA traffic test driver
4  *
5  * Copyright (C) 2020, Intel Corporation
6  * Authors: Isaac Hazan <isaac.hazan@intel.com>
7  *	    Mika Westerberg <mika.westerberg@linux.intel.com>
8  */
9 
10 #include <linux/completion.h>
11 #include <linux/debugfs.h>
12 #include <linux/module.h>
13 #include <linux/sizes.h>
14 #include <linux/thunderbolt.h>
15 
16 #define DMA_TEST_TX_RING_SIZE		64
17 #define DMA_TEST_RX_RING_SIZE		256
18 #define DMA_TEST_FRAME_SIZE		SZ_4K
19 #define DMA_TEST_DATA_PATTERN		0x0123456789abcdefLL
20 #define DMA_TEST_MAX_PACKETS		1000
21 
22 enum dma_test_frame_pdf {
23 	DMA_TEST_PDF_FRAME_START = 1,
24 	DMA_TEST_PDF_FRAME_END,
25 };
26 
27 struct dma_test_frame {
28 	struct dma_test *dma_test;
29 	void *data;
30 	struct ring_frame frame;
31 };
32 
33 enum dma_test_test_error {
34 	DMA_TEST_NO_ERROR,
35 	DMA_TEST_INTERRUPTED,
36 	DMA_TEST_BUFFER_ERROR,
37 	DMA_TEST_DMA_ERROR,
38 	DMA_TEST_CONFIG_ERROR,
39 	DMA_TEST_SPEED_ERROR,
40 	DMA_TEST_WIDTH_ERROR,
41 	DMA_TEST_BONDING_ERROR,
42 	DMA_TEST_PACKET_ERROR,
43 };
44 
45 static const char * const dma_test_error_names[] = {
46 	[DMA_TEST_NO_ERROR] = "no errors",
47 	[DMA_TEST_INTERRUPTED] = "interrupted by signal",
48 	[DMA_TEST_BUFFER_ERROR] = "no memory for packet buffers",
49 	[DMA_TEST_DMA_ERROR] = "DMA ring setup failed",
50 	[DMA_TEST_CONFIG_ERROR] = "configuration is not valid",
51 	[DMA_TEST_SPEED_ERROR] = "unexpected link speed",
52 	[DMA_TEST_WIDTH_ERROR] = "unexpected link width",
53 	[DMA_TEST_BONDING_ERROR] = "lane bonding configuration error",
54 	[DMA_TEST_PACKET_ERROR] = "packet check failed",
55 };
56 
57 enum dma_test_result {
58 	DMA_TEST_NOT_RUN,
59 	DMA_TEST_SUCCESS,
60 	DMA_TEST_FAIL,
61 };
62 
63 static const char * const dma_test_result_names[] = {
64 	[DMA_TEST_NOT_RUN] = "not run",
65 	[DMA_TEST_SUCCESS] = "success",
66 	[DMA_TEST_FAIL] = "failed",
67 };
68 
69 /**
70  * struct dma_test - DMA test device driver private data
71  * @svc: XDomain service the driver is bound to
72  * @xd: XDomain the service belongs to
73  * @rx_ring: Software ring holding RX frames
74  * @rx_hopid: HopID used for receiving frames
75  * @tx_ring: Software ring holding TX frames
76  * @tx_hopid: HopID used for sending fames
77  * @packets_to_send: Number of packets to send
78  * @packets_to_receive: Number of packets to receive
79  * @packets_sent: Actual number of packets sent
80  * @packets_received: Actual number of packets received
81  * @link_speed: Expected link speed (Gb/s), %0 to use whatever is negotiated
82  * @link_width: Expected link width (Gb/s), %0 to use whatever is negotiated
83  * @crc_errors: Number of CRC errors during the test run
84  * @buffer_overflow_errors: Number of buffer overflow errors during the test
85  *			    run
86  * @result: Result of the last run
87  * @error_code: Error code of the last run
88  * @complete: Used to wait for the Rx to complete
89  * @lock: Lock serializing access to this structure
90  * @debugfs_dir: dentry of this dma_test
91  */
92 struct dma_test {
93 	const struct tb_service *svc;
94 	struct tb_xdomain *xd;
95 	struct tb_ring *rx_ring;
96 	int rx_hopid;
97 	struct tb_ring *tx_ring;
98 	int tx_hopid;
99 	unsigned int packets_to_send;
100 	unsigned int packets_to_receive;
101 	unsigned int packets_sent;
102 	unsigned int packets_received;
103 	unsigned int link_speed;
104 	unsigned int link_width;
105 	unsigned int crc_errors;
106 	unsigned int buffer_overflow_errors;
107 	enum dma_test_result result;
108 	enum dma_test_test_error error_code;
109 	struct completion complete;
110 	struct mutex lock;
111 	struct dentry *debugfs_dir;
112 };
113 
114 /* DMA test property directory UUID: 3188cd10-6523-4a5a-a682-fdca07a248d8 */
115 static const uuid_t dma_test_dir_uuid =
116 	UUID_INIT(0x3188cd10, 0x6523, 0x4a5a,
117 		  0xa6, 0x82, 0xfd, 0xca, 0x07, 0xa2, 0x48, 0xd8);
118 
119 static struct tb_property_dir *dma_test_dir;
120 static void *dma_test_pattern;
121 
122 static void dma_test_free_rings(struct dma_test *dt)
123 {
124 	if (dt->rx_ring) {
125 		tb_xdomain_release_in_hopid(dt->xd, dt->rx_hopid);
126 		tb_ring_free(dt->rx_ring);
127 		dt->rx_ring = NULL;
128 	}
129 	if (dt->tx_ring) {
130 		tb_xdomain_release_out_hopid(dt->xd, dt->tx_hopid);
131 		tb_ring_free(dt->tx_ring);
132 		dt->tx_ring = NULL;
133 	}
134 }
135 
136 static int dma_test_start_rings(struct dma_test *dt)
137 {
138 	unsigned int flags = RING_FLAG_FRAME;
139 	struct tb_xdomain *xd = dt->xd;
140 	int ret, e2e_tx_hop = 0;
141 	struct tb_ring *ring;
142 
143 	/*
144 	 * If we are both sender and receiver (traffic goes over a
145 	 * special loopback dongle) enable E2E flow control. This avoids
146 	 * losing packets.
147 	 */
148 	if (dt->packets_to_send && dt->packets_to_receive)
149 		flags |= RING_FLAG_E2E;
150 
151 	if (dt->packets_to_send) {
152 		ring = tb_ring_alloc_tx(xd->tb->nhi, -1, DMA_TEST_TX_RING_SIZE,
153 					flags);
154 		if (!ring)
155 			return -ENOMEM;
156 
157 		dt->tx_ring = ring;
158 		e2e_tx_hop = ring->hop;
159 
160 		ret = tb_xdomain_alloc_out_hopid(xd, -1);
161 		if (ret < 0) {
162 			dma_test_free_rings(dt);
163 			return ret;
164 		}
165 
166 		dt->tx_hopid = ret;
167 	}
168 
169 	if (dt->packets_to_receive) {
170 		u16 sof_mask, eof_mask;
171 
172 		sof_mask = BIT(DMA_TEST_PDF_FRAME_START);
173 		eof_mask = BIT(DMA_TEST_PDF_FRAME_END);
174 
175 		ring = tb_ring_alloc_rx(xd->tb->nhi, -1, DMA_TEST_RX_RING_SIZE,
176 					flags, e2e_tx_hop, sof_mask, eof_mask,
177 					NULL, NULL);
178 		if (!ring) {
179 			dma_test_free_rings(dt);
180 			return -ENOMEM;
181 		}
182 
183 		dt->rx_ring = ring;
184 
185 		ret = tb_xdomain_alloc_in_hopid(xd, -1);
186 		if (ret < 0) {
187 			dma_test_free_rings(dt);
188 			return ret;
189 		}
190 
191 		dt->rx_hopid = ret;
192 	}
193 
194 	ret = tb_xdomain_enable_paths(dt->xd, dt->tx_hopid,
195 				      dt->tx_ring ? dt->tx_ring->hop : 0,
196 				      dt->rx_hopid,
197 				      dt->rx_ring ? dt->rx_ring->hop : 0);
198 	if (ret) {
199 		dma_test_free_rings(dt);
200 		return ret;
201 	}
202 
203 	if (dt->tx_ring)
204 		tb_ring_start(dt->tx_ring);
205 	if (dt->rx_ring)
206 		tb_ring_start(dt->rx_ring);
207 
208 	return 0;
209 }
210 
211 static void dma_test_stop_rings(struct dma_test *dt)
212 {
213 	int ret;
214 
215 	if (dt->rx_ring)
216 		tb_ring_stop(dt->rx_ring);
217 	if (dt->tx_ring)
218 		tb_ring_stop(dt->tx_ring);
219 
220 	ret = tb_xdomain_disable_paths(dt->xd, dt->tx_hopid,
221 				       dt->tx_ring ? dt->tx_ring->hop : 0,
222 				       dt->rx_hopid,
223 				       dt->rx_ring ? dt->rx_ring->hop : 0);
224 	if (ret)
225 		dev_warn(&dt->svc->dev, "failed to disable DMA paths\n");
226 
227 	dma_test_free_rings(dt);
228 }
229 
230 static void dma_test_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
231 				 bool canceled)
232 {
233 	struct dma_test_frame *tf = container_of(frame, typeof(*tf), frame);
234 	struct dma_test *dt = tf->dma_test;
235 	struct device *dma_dev = tb_ring_dma_device(dt->rx_ring);
236 
237 	dma_unmap_single(dma_dev, tf->frame.buffer_phy, DMA_TEST_FRAME_SIZE,
238 			 DMA_FROM_DEVICE);
239 	kfree(tf->data);
240 
241 	if (canceled) {
242 		kfree(tf);
243 		return;
244 	}
245 
246 	dt->packets_received++;
247 	dev_dbg(&dt->svc->dev, "packet %u/%u received\n", dt->packets_received,
248 		dt->packets_to_receive);
249 
250 	if (tf->frame.flags & RING_DESC_CRC_ERROR)
251 		dt->crc_errors++;
252 	if (tf->frame.flags & RING_DESC_BUFFER_OVERRUN)
253 		dt->buffer_overflow_errors++;
254 
255 	kfree(tf);
256 
257 	if (dt->packets_received == dt->packets_to_receive)
258 		complete(&dt->complete);
259 }
260 
261 static int dma_test_submit_rx(struct dma_test *dt, size_t npackets)
262 {
263 	struct device *dma_dev = tb_ring_dma_device(dt->rx_ring);
264 	int i;
265 
266 	for (i = 0; i < npackets; i++) {
267 		struct dma_test_frame *tf;
268 		dma_addr_t dma_addr;
269 
270 		tf = kzalloc(sizeof(*tf), GFP_KERNEL);
271 		if (!tf)
272 			return -ENOMEM;
273 
274 		tf->data = kzalloc(DMA_TEST_FRAME_SIZE, GFP_KERNEL);
275 		if (!tf->data) {
276 			kfree(tf);
277 			return -ENOMEM;
278 		}
279 
280 		dma_addr = dma_map_single(dma_dev, tf->data, DMA_TEST_FRAME_SIZE,
281 					  DMA_FROM_DEVICE);
282 		if (dma_mapping_error(dma_dev, dma_addr)) {
283 			kfree(tf->data);
284 			kfree(tf);
285 			return -ENOMEM;
286 		}
287 
288 		tf->frame.buffer_phy = dma_addr;
289 		tf->frame.callback = dma_test_rx_callback;
290 		tf->dma_test = dt;
291 		INIT_LIST_HEAD(&tf->frame.list);
292 
293 		tb_ring_rx(dt->rx_ring, &tf->frame);
294 	}
295 
296 	return 0;
297 }
298 
299 static void dma_test_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
300 				 bool canceled)
301 {
302 	struct dma_test_frame *tf = container_of(frame, typeof(*tf), frame);
303 	struct dma_test *dt = tf->dma_test;
304 	struct device *dma_dev = tb_ring_dma_device(dt->tx_ring);
305 
306 	dma_unmap_single(dma_dev, tf->frame.buffer_phy, DMA_TEST_FRAME_SIZE,
307 			 DMA_TO_DEVICE);
308 	kfree(tf->data);
309 	kfree(tf);
310 }
311 
312 static int dma_test_submit_tx(struct dma_test *dt, size_t npackets)
313 {
314 	struct device *dma_dev = tb_ring_dma_device(dt->tx_ring);
315 	int i;
316 
317 	for (i = 0; i < npackets; i++) {
318 		struct dma_test_frame *tf;
319 		dma_addr_t dma_addr;
320 
321 		tf = kzalloc(sizeof(*tf), GFP_KERNEL);
322 		if (!tf)
323 			return -ENOMEM;
324 
325 		tf->frame.size = 0; /* means 4096 */
326 		tf->dma_test = dt;
327 
328 		tf->data = kmemdup(dma_test_pattern, DMA_TEST_FRAME_SIZE, GFP_KERNEL);
329 		if (!tf->data) {
330 			kfree(tf);
331 			return -ENOMEM;
332 		}
333 
334 		dma_addr = dma_map_single(dma_dev, tf->data, DMA_TEST_FRAME_SIZE,
335 					  DMA_TO_DEVICE);
336 		if (dma_mapping_error(dma_dev, dma_addr)) {
337 			kfree(tf->data);
338 			kfree(tf);
339 			return -ENOMEM;
340 		}
341 
342 		tf->frame.buffer_phy = dma_addr;
343 		tf->frame.callback = dma_test_tx_callback;
344 		tf->frame.sof = DMA_TEST_PDF_FRAME_START;
345 		tf->frame.eof = DMA_TEST_PDF_FRAME_END;
346 		INIT_LIST_HEAD(&tf->frame.list);
347 
348 		dt->packets_sent++;
349 		dev_dbg(&dt->svc->dev, "packet %u/%u sent\n", dt->packets_sent,
350 			dt->packets_to_send);
351 
352 		tb_ring_tx(dt->tx_ring, &tf->frame);
353 	}
354 
355 	return 0;
356 }
357 
358 #define DMA_TEST_DEBUGFS_ATTR(__fops, __get, __validate, __set)	\
359 static int __fops ## _show(void *data, u64 *val)		\
360 {								\
361 	struct tb_service *svc = data;				\
362 	struct dma_test *dt = tb_service_get_drvdata(svc);	\
363 	int ret;						\
364 								\
365 	ret = mutex_lock_interruptible(&dt->lock);		\
366 	if (ret)						\
367 		return ret;					\
368 	__get(dt, val);						\
369 	mutex_unlock(&dt->lock);				\
370 	return 0;						\
371 }								\
372 static int __fops ## _store(void *data, u64 val)		\
373 {								\
374 	struct tb_service *svc = data;				\
375 	struct dma_test *dt = tb_service_get_drvdata(svc);	\
376 	int ret;						\
377 								\
378 	ret = __validate(val);					\
379 	if (ret)						\
380 		return ret;					\
381 	ret = mutex_lock_interruptible(&dt->lock);		\
382 	if (ret)						\
383 		return ret;					\
384 	__set(dt, val);						\
385 	mutex_unlock(&dt->lock);				\
386 	return 0;						\
387 }								\
388 DEFINE_DEBUGFS_ATTRIBUTE(__fops ## _fops, __fops ## _show,	\
389 			 __fops ## _store, "%llu\n")
390 
391 static void lanes_get(const struct dma_test *dt, u64 *val)
392 {
393 	*val = dt->link_width;
394 }
395 
396 static int lanes_validate(u64 val)
397 {
398 	return val > 2 ? -EINVAL : 0;
399 }
400 
401 static void lanes_set(struct dma_test *dt, u64 val)
402 {
403 	dt->link_width = val;
404 }
405 DMA_TEST_DEBUGFS_ATTR(lanes, lanes_get, lanes_validate, lanes_set);
406 
407 static void speed_get(const struct dma_test *dt, u64 *val)
408 {
409 	*val = dt->link_speed;
410 }
411 
412 static int speed_validate(u64 val)
413 {
414 	switch (val) {
415 	case 20:
416 	case 10:
417 	case 0:
418 		return 0;
419 	default:
420 		return -EINVAL;
421 	}
422 }
423 
424 static void speed_set(struct dma_test *dt, u64 val)
425 {
426 	dt->link_speed = val;
427 }
428 DMA_TEST_DEBUGFS_ATTR(speed, speed_get, speed_validate, speed_set);
429 
430 static void packets_to_receive_get(const struct dma_test *dt, u64 *val)
431 {
432 	*val = dt->packets_to_receive;
433 }
434 
435 static int packets_to_receive_validate(u64 val)
436 {
437 	return val > DMA_TEST_MAX_PACKETS ? -EINVAL : 0;
438 }
439 
440 static void packets_to_receive_set(struct dma_test *dt, u64 val)
441 {
442 	dt->packets_to_receive = val;
443 }
444 DMA_TEST_DEBUGFS_ATTR(packets_to_receive, packets_to_receive_get,
445 		      packets_to_receive_validate, packets_to_receive_set);
446 
447 static void packets_to_send_get(const struct dma_test *dt, u64 *val)
448 {
449 	*val = dt->packets_to_send;
450 }
451 
452 static int packets_to_send_validate(u64 val)
453 {
454 	return val > DMA_TEST_MAX_PACKETS ? -EINVAL : 0;
455 }
456 
457 static void packets_to_send_set(struct dma_test *dt, u64 val)
458 {
459 	dt->packets_to_send = val;
460 }
461 DMA_TEST_DEBUGFS_ATTR(packets_to_send, packets_to_send_get,
462 		      packets_to_send_validate, packets_to_send_set);
463 
464 static int dma_test_set_bonding(struct dma_test *dt)
465 {
466 	switch (dt->link_width) {
467 	case 2:
468 		return tb_xdomain_lane_bonding_enable(dt->xd);
469 	case 1:
470 		tb_xdomain_lane_bonding_disable(dt->xd);
471 		fallthrough;
472 	default:
473 		return 0;
474 	}
475 }
476 
477 static bool dma_test_validate_config(struct dma_test *dt)
478 {
479 	if (!dt->packets_to_send && !dt->packets_to_receive)
480 		return false;
481 	if (dt->packets_to_send && dt->packets_to_receive &&
482 	    dt->packets_to_send != dt->packets_to_receive)
483 		return false;
484 	return true;
485 }
486 
487 static void dma_test_check_errors(struct dma_test *dt, int ret)
488 {
489 	if (!dt->error_code) {
490 		if (dt->link_speed && dt->xd->link_speed != dt->link_speed) {
491 			dt->error_code = DMA_TEST_SPEED_ERROR;
492 		} else if (dt->link_width &&
493 			   dt->xd->link_width != dt->link_width) {
494 			dt->error_code = DMA_TEST_WIDTH_ERROR;
495 		} else if (dt->packets_to_send != dt->packets_sent ||
496 			 dt->packets_to_receive != dt->packets_received ||
497 			 dt->crc_errors || dt->buffer_overflow_errors) {
498 			dt->error_code = DMA_TEST_PACKET_ERROR;
499 		} else {
500 			return;
501 		}
502 	}
503 
504 	dt->result = DMA_TEST_FAIL;
505 }
506 
507 static int test_store(void *data, u64 val)
508 {
509 	struct tb_service *svc = data;
510 	struct dma_test *dt = tb_service_get_drvdata(svc);
511 	int ret;
512 
513 	if (val != 1)
514 		return -EINVAL;
515 
516 	ret = mutex_lock_interruptible(&dt->lock);
517 	if (ret)
518 		return ret;
519 
520 	dt->packets_sent = 0;
521 	dt->packets_received = 0;
522 	dt->crc_errors = 0;
523 	dt->buffer_overflow_errors = 0;
524 	dt->result = DMA_TEST_SUCCESS;
525 	dt->error_code = DMA_TEST_NO_ERROR;
526 
527 	dev_dbg(&svc->dev, "DMA test starting\n");
528 	if (dt->link_speed)
529 		dev_dbg(&svc->dev, "link_speed: %u Gb/s\n", dt->link_speed);
530 	if (dt->link_width)
531 		dev_dbg(&svc->dev, "link_width: %u\n", dt->link_width);
532 	dev_dbg(&svc->dev, "packets_to_send: %u\n", dt->packets_to_send);
533 	dev_dbg(&svc->dev, "packets_to_receive: %u\n", dt->packets_to_receive);
534 
535 	if (!dma_test_validate_config(dt)) {
536 		dev_err(&svc->dev, "invalid test configuration\n");
537 		dt->error_code = DMA_TEST_CONFIG_ERROR;
538 		goto out_unlock;
539 	}
540 
541 	ret = dma_test_set_bonding(dt);
542 	if (ret) {
543 		dev_err(&svc->dev, "failed to set lanes\n");
544 		dt->error_code = DMA_TEST_BONDING_ERROR;
545 		goto out_unlock;
546 	}
547 
548 	ret = dma_test_start_rings(dt);
549 	if (ret) {
550 		dev_err(&svc->dev, "failed to enable DMA rings\n");
551 		dt->error_code = DMA_TEST_DMA_ERROR;
552 		goto out_unlock;
553 	}
554 
555 	if (dt->packets_to_receive) {
556 		reinit_completion(&dt->complete);
557 		ret = dma_test_submit_rx(dt, dt->packets_to_receive);
558 		if (ret) {
559 			dev_err(&svc->dev, "failed to submit receive buffers\n");
560 			dt->error_code = DMA_TEST_BUFFER_ERROR;
561 			goto out_stop;
562 		}
563 	}
564 
565 	if (dt->packets_to_send) {
566 		ret = dma_test_submit_tx(dt, dt->packets_to_send);
567 		if (ret) {
568 			dev_err(&svc->dev, "failed to submit transmit buffers\n");
569 			dt->error_code = DMA_TEST_BUFFER_ERROR;
570 			goto out_stop;
571 		}
572 	}
573 
574 	if (dt->packets_to_receive) {
575 		ret = wait_for_completion_interruptible(&dt->complete);
576 		if (ret) {
577 			dt->error_code = DMA_TEST_INTERRUPTED;
578 			goto out_stop;
579 		}
580 	}
581 
582 out_stop:
583 	dma_test_stop_rings(dt);
584 out_unlock:
585 	dma_test_check_errors(dt, ret);
586 	mutex_unlock(&dt->lock);
587 
588 	dev_dbg(&svc->dev, "DMA test %s\n", dma_test_result_names[dt->result]);
589 	return ret;
590 }
591 DEFINE_DEBUGFS_ATTRIBUTE(test_fops, NULL, test_store, "%llu\n");
592 
593 static int status_show(struct seq_file *s, void *not_used)
594 {
595 	struct tb_service *svc = s->private;
596 	struct dma_test *dt = tb_service_get_drvdata(svc);
597 	int ret;
598 
599 	ret = mutex_lock_interruptible(&dt->lock);
600 	if (ret)
601 		return ret;
602 
603 	seq_printf(s, "result: %s\n", dma_test_result_names[dt->result]);
604 	if (dt->result == DMA_TEST_NOT_RUN)
605 		goto out_unlock;
606 
607 	seq_printf(s, "packets received: %u\n", dt->packets_received);
608 	seq_printf(s, "packets sent: %u\n", dt->packets_sent);
609 	seq_printf(s, "CRC errors: %u\n", dt->crc_errors);
610 	seq_printf(s, "buffer overflow errors: %u\n",
611 		   dt->buffer_overflow_errors);
612 	seq_printf(s, "error: %s\n", dma_test_error_names[dt->error_code]);
613 
614 out_unlock:
615 	mutex_unlock(&dt->lock);
616 	return 0;
617 }
618 DEFINE_SHOW_ATTRIBUTE(status);
619 
620 static void dma_test_debugfs_init(struct tb_service *svc)
621 {
622 	struct dma_test *dt = tb_service_get_drvdata(svc);
623 
624 	dt->debugfs_dir = debugfs_create_dir("dma_test", svc->debugfs_dir);
625 
626 	debugfs_create_file("lanes", 0600, dt->debugfs_dir, svc, &lanes_fops);
627 	debugfs_create_file("speed", 0600, dt->debugfs_dir, svc, &speed_fops);
628 	debugfs_create_file("packets_to_receive", 0600, dt->debugfs_dir, svc,
629 			    &packets_to_receive_fops);
630 	debugfs_create_file("packets_to_send", 0600, dt->debugfs_dir, svc,
631 			    &packets_to_send_fops);
632 	debugfs_create_file("status", 0400, dt->debugfs_dir, svc, &status_fops);
633 	debugfs_create_file("test", 0200, dt->debugfs_dir, svc, &test_fops);
634 }
635 
636 static int dma_test_probe(struct tb_service *svc, const struct tb_service_id *id)
637 {
638 	struct tb_xdomain *xd = tb_service_parent(svc);
639 	struct dma_test *dt;
640 
641 	dt = devm_kzalloc(&svc->dev, sizeof(*dt), GFP_KERNEL);
642 	if (!dt)
643 		return -ENOMEM;
644 
645 	dt->svc = svc;
646 	dt->xd = xd;
647 	mutex_init(&dt->lock);
648 	init_completion(&dt->complete);
649 
650 	tb_service_set_drvdata(svc, dt);
651 	dma_test_debugfs_init(svc);
652 
653 	return 0;
654 }
655 
656 static void dma_test_remove(struct tb_service *svc)
657 {
658 	struct dma_test *dt = tb_service_get_drvdata(svc);
659 
660 	mutex_lock(&dt->lock);
661 	debugfs_remove_recursive(dt->debugfs_dir);
662 	mutex_unlock(&dt->lock);
663 }
664 
665 static int __maybe_unused dma_test_suspend(struct device *dev)
666 {
667 	/*
668 	 * No need to do anything special here. If userspace is writing
669 	 * to the test attribute when suspend started, it comes out from
670 	 * wait_for_completion_interruptible() with -ERESTARTSYS and the
671 	 * DMA test fails tearing down the rings. Once userspace is
672 	 * thawed the kernel restarts the write syscall effectively
673 	 * re-running the test.
674 	 */
675 	return 0;
676 }
677 
678 static int __maybe_unused dma_test_resume(struct device *dev)
679 {
680 	return 0;
681 }
682 
683 static const struct dev_pm_ops dma_test_pm_ops = {
684 	SET_SYSTEM_SLEEP_PM_OPS(dma_test_suspend, dma_test_resume)
685 };
686 
687 static const struct tb_service_id dma_test_ids[] = {
688 	{ TB_SERVICE("dma_test", 1) },
689 	{ },
690 };
691 MODULE_DEVICE_TABLE(tbsvc, dma_test_ids);
692 
693 static struct tb_service_driver dma_test_driver = {
694 	.driver = {
695 		.owner = THIS_MODULE,
696 		.name = "thunderbolt_dma_test",
697 		.pm = &dma_test_pm_ops,
698 	},
699 	.probe = dma_test_probe,
700 	.remove = dma_test_remove,
701 	.id_table = dma_test_ids,
702 };
703 
704 static int __init dma_test_init(void)
705 {
706 	u64 data_value = DMA_TEST_DATA_PATTERN;
707 	int i, ret;
708 
709 	dma_test_pattern = kmalloc(DMA_TEST_FRAME_SIZE, GFP_KERNEL);
710 	if (!dma_test_pattern)
711 		return -ENOMEM;
712 
713 	for (i = 0; i <	DMA_TEST_FRAME_SIZE / sizeof(data_value); i++)
714 		((u32 *)dma_test_pattern)[i] = data_value++;
715 
716 	dma_test_dir = tb_property_create_dir(&dma_test_dir_uuid);
717 	if (!dma_test_dir) {
718 		ret = -ENOMEM;
719 		goto err_free_pattern;
720 	}
721 
722 	tb_property_add_immediate(dma_test_dir, "prtcid", 1);
723 	tb_property_add_immediate(dma_test_dir, "prtcvers", 1);
724 	tb_property_add_immediate(dma_test_dir, "prtcrevs", 0);
725 	tb_property_add_immediate(dma_test_dir, "prtcstns", 0);
726 
727 	ret = tb_register_property_dir("dma_test", dma_test_dir);
728 	if (ret)
729 		goto err_free_dir;
730 
731 	ret = tb_register_service_driver(&dma_test_driver);
732 	if (ret)
733 		goto err_unregister_dir;
734 
735 	return 0;
736 
737 err_unregister_dir:
738 	tb_unregister_property_dir("dma_test", dma_test_dir);
739 err_free_dir:
740 	tb_property_free_dir(dma_test_dir);
741 err_free_pattern:
742 	kfree(dma_test_pattern);
743 
744 	return ret;
745 }
746 module_init(dma_test_init);
747 
748 static void __exit dma_test_exit(void)
749 {
750 	tb_unregister_service_driver(&dma_test_driver);
751 	tb_unregister_property_dir("dma_test", dma_test_dir);
752 	tb_property_free_dir(dma_test_dir);
753 	kfree(dma_test_pattern);
754 }
755 module_exit(dma_test_exit);
756 
757 MODULE_AUTHOR("Isaac Hazan <isaac.hazan@intel.com>");
758 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
759 MODULE_DESCRIPTION("DMA traffic test driver");
760 MODULE_LICENSE("GPL v2");
761