1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 Avionic Design GmbH
4 * Copyright (C) 2012-2013, NVIDIA Corporation
5 */
6
7#include <linux/debugfs.h>
8#include <linux/dma-mapping.h>
9#include <linux/host1x.h>
10#include <linux/of.h>
11#include <linux/seq_file.h>
12#include <linux/slab.h>
13#include <linux/of_device.h>
14
15#include "bus.h"
16#include "dev.h"
17
18static DEFINE_MUTEX(clients_lock);
19static LIST_HEAD(clients);
20
21static DEFINE_MUTEX(drivers_lock);
22static LIST_HEAD(drivers);
23
24static DEFINE_MUTEX(devices_lock);
25static LIST_HEAD(devices);
26
27struct host1x_subdev {
28	struct host1x_client *client;
29	struct device_node *np;
30	struct list_head list;
31};
32
33/**
34 * host1x_subdev_add() - add a new subdevice with an associated device node
35 * @device: host1x device to add the subdevice to
36 * @driver: host1x driver containing the subdevices
37 * @np: device node
38 */
39static int host1x_subdev_add(struct host1x_device *device,
40			     struct host1x_driver *driver,
41			     struct device_node *np)
42{
43	struct host1x_subdev *subdev;
44	struct device_node *child;
45	int err;
46
47	subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
48	if (!subdev)
49		return -ENOMEM;
50
51	INIT_LIST_HEAD(&subdev->list);
52	subdev->np = of_node_get(np);
53
54	mutex_lock(&device->subdevs_lock);
55	list_add_tail(&subdev->list, &device->subdevs);
56	mutex_unlock(&device->subdevs_lock);
57
58	/* recursively add children */
59	for_each_child_of_node(np, child) {
60		if (of_match_node(driver->subdevs, child) &&
61		    of_device_is_available(child)) {
62			err = host1x_subdev_add(device, driver, child);
63			if (err < 0) {
64				/* XXX cleanup? */
65				of_node_put(child);
66				return err;
67			}
68		}
69	}
70
71	return 0;
72}
73
74/**
75 * host1x_subdev_del() - remove subdevice
76 * @subdev: subdevice to remove
77 */
78static void host1x_subdev_del(struct host1x_subdev *subdev)
79{
80	list_del(&subdev->list);
81	of_node_put(subdev->np);
82	kfree(subdev);
83}
84
85/**
86 * host1x_device_parse_dt() - scan device tree and add matching subdevices
87 * @device: host1x logical device
88 * @driver: host1x driver
89 */
90static int host1x_device_parse_dt(struct host1x_device *device,
91				  struct host1x_driver *driver)
92{
93	struct device_node *np;
94	int err;
95
96	for_each_child_of_node(device->dev.parent->of_node, np) {
97		if (of_match_node(driver->subdevs, np) &&
98		    of_device_is_available(np)) {
99			err = host1x_subdev_add(device, driver, np);
100			if (err < 0) {
101				of_node_put(np);
102				return err;
103			}
104		}
105	}
106
107	return 0;
108}
109
110static void host1x_subdev_register(struct host1x_device *device,
111				   struct host1x_subdev *subdev,
112				   struct host1x_client *client)
113{
114	int err;
115
116	/*
117	 * Move the subdevice to the list of active (registered) subdevices
118	 * and associate it with a client. At the same time, associate the
119	 * client with its parent device.
120	 */
121	mutex_lock(&device->subdevs_lock);
122	mutex_lock(&device->clients_lock);
123	list_move_tail(&client->list, &device->clients);
124	list_move_tail(&subdev->list, &device->active);
125	client->host = &device->dev;
126	subdev->client = client;
127	mutex_unlock(&device->clients_lock);
128	mutex_unlock(&device->subdevs_lock);
129
130	if (list_empty(&device->subdevs)) {
131		err = device_add(&device->dev);
132		if (err < 0)
133			dev_err(&device->dev, "failed to add: %d\n", err);
134		else
135			device->registered = true;
136	}
137}
138
139static void __host1x_subdev_unregister(struct host1x_device *device,
140				       struct host1x_subdev *subdev)
141{
142	struct host1x_client *client = subdev->client;
143
144	/*
145	 * If all subdevices have been activated, we're about to remove the
146	 * first active subdevice, so unload the driver first.
147	 */
148	if (list_empty(&device->subdevs)) {
149		if (device->registered) {
150			device->registered = false;
151			device_del(&device->dev);
152		}
153	}
154
155	/*
156	 * Move the subdevice back to the list of idle subdevices and remove
157	 * it from list of clients.
158	 */
159	mutex_lock(&device->clients_lock);
160	subdev->client = NULL;
161	client->host = NULL;
162	list_move_tail(&subdev->list, &device->subdevs);
163	/*
164	 * XXX: Perhaps don't do this here, but rather explicitly remove it
165	 * when the device is about to be deleted.
166	 *
167	 * This is somewhat complicated by the fact that this function is
168	 * used to remove the subdevice when a client is unregistered but
169	 * also when the composite device is about to be removed.
170	 */
171	list_del_init(&client->list);
172	mutex_unlock(&device->clients_lock);
173}
174
175static void host1x_subdev_unregister(struct host1x_device *device,
176				     struct host1x_subdev *subdev)
177{
178	mutex_lock(&device->subdevs_lock);
179	__host1x_subdev_unregister(device, subdev);
180	mutex_unlock(&device->subdevs_lock);
181}
182
183/**
184 * host1x_device_init() - initialize a host1x logical device
185 * @device: host1x logical device
186 *
187 * The driver for the host1x logical device can call this during execution of
188 * its &host1x_driver.probe implementation to initialize each of its clients.
189 * The client drivers access the subsystem specific driver data using the
190 * &host1x_client.parent field and driver data associated with it (usually by
191 * calling dev_get_drvdata()).
192 */
193int host1x_device_init(struct host1x_device *device)
194{
195	struct host1x_client *client;
196	int err;
197
198	mutex_lock(&device->clients_lock);
199
200	list_for_each_entry(client, &device->clients, list) {
201		if (client->ops && client->ops->early_init) {
202			err = client->ops->early_init(client);
203			if (err < 0) {
204				dev_err(&device->dev, "failed to early initialize %s: %d\n",
205					dev_name(client->dev), err);
206				goto teardown_late;
207			}
208		}
209	}
210
211	list_for_each_entry(client, &device->clients, list) {
212		if (client->ops && client->ops->init) {
213			err = client->ops->init(client);
214			if (err < 0) {
215				dev_err(&device->dev,
216					"failed to initialize %s: %d\n",
217					dev_name(client->dev), err);
218				goto teardown;
219			}
220		}
221	}
222
223	mutex_unlock(&device->clients_lock);
224
225	return 0;
226
227teardown:
228	list_for_each_entry_continue_reverse(client, &device->clients, list)
229		if (client->ops->exit)
230			client->ops->exit(client);
231
232	/* reset client to end of list for late teardown */
233	client = list_entry(&device->clients, struct host1x_client, list);
234
235teardown_late:
236	list_for_each_entry_continue_reverse(client, &device->clients, list)
237		if (client->ops->late_exit)
238			client->ops->late_exit(client);
239
240	mutex_unlock(&device->clients_lock);
241	return err;
242}
243EXPORT_SYMBOL(host1x_device_init);
244
245/**
246 * host1x_device_exit() - uninitialize host1x logical device
247 * @device: host1x logical device
248 *
249 * When the driver for a host1x logical device is unloaded, it can call this
250 * function to tear down each of its clients. Typically this is done after a
251 * subsystem-specific data structure is removed and the functionality can no
252 * longer be used.
253 */
254int host1x_device_exit(struct host1x_device *device)
255{
256	struct host1x_client *client;
257	int err;
258
259	mutex_lock(&device->clients_lock);
260
261	list_for_each_entry_reverse(client, &device->clients, list) {
262		if (client->ops && client->ops->exit) {
263			err = client->ops->exit(client);
264			if (err < 0) {
265				dev_err(&device->dev,
266					"failed to cleanup %s: %d\n",
267					dev_name(client->dev), err);
268				mutex_unlock(&device->clients_lock);
269				return err;
270			}
271		}
272	}
273
274	list_for_each_entry_reverse(client, &device->clients, list) {
275		if (client->ops && client->ops->late_exit) {
276			err = client->ops->late_exit(client);
277			if (err < 0) {
278				dev_err(&device->dev, "failed to late cleanup %s: %d\n",
279					dev_name(client->dev), err);
280				mutex_unlock(&device->clients_lock);
281				return err;
282			}
283		}
284	}
285
286	mutex_unlock(&device->clients_lock);
287
288	return 0;
289}
290EXPORT_SYMBOL(host1x_device_exit);
291
292static int host1x_add_client(struct host1x *host1x,
293			     struct host1x_client *client)
294{
295	struct host1x_device *device;
296	struct host1x_subdev *subdev;
297
298	mutex_lock(&host1x->devices_lock);
299
300	list_for_each_entry(device, &host1x->devices, list) {
301		list_for_each_entry(subdev, &device->subdevs, list) {
302			if (subdev->np == client->dev->of_node) {
303				host1x_subdev_register(device, subdev, client);
304				mutex_unlock(&host1x->devices_lock);
305				return 0;
306			}
307		}
308	}
309
310	mutex_unlock(&host1x->devices_lock);
311	return -ENODEV;
312}
313
314static int host1x_del_client(struct host1x *host1x,
315			     struct host1x_client *client)
316{
317	struct host1x_device *device, *dt;
318	struct host1x_subdev *subdev;
319
320	mutex_lock(&host1x->devices_lock);
321
322	list_for_each_entry_safe(device, dt, &host1x->devices, list) {
323		list_for_each_entry(subdev, &device->active, list) {
324			if (subdev->client == client) {
325				host1x_subdev_unregister(device, subdev);
326				mutex_unlock(&host1x->devices_lock);
327				return 0;
328			}
329		}
330	}
331
332	mutex_unlock(&host1x->devices_lock);
333	return -ENODEV;
334}
335
336static int host1x_device_match(struct device *dev, struct device_driver *drv)
337{
338	return strcmp(dev_name(dev), drv->name) == 0;
339}
340
341/*
342 * Note that this is really only needed for backwards compatibility
343 * with libdrm, which parses this information from sysfs and will
344 * fail if it can't find the OF_FULLNAME, specifically.
345 */
346static int host1x_device_uevent(const struct device *dev,
347				struct kobj_uevent_env *env)
348{
349	of_device_uevent(dev->parent, env);
350
351	return 0;
352}
353
354static const struct dev_pm_ops host1x_device_pm_ops = {
355	.suspend = pm_generic_suspend,
356	.resume = pm_generic_resume,
357	.freeze = pm_generic_freeze,
358	.thaw = pm_generic_thaw,
359	.poweroff = pm_generic_poweroff,
360	.restore = pm_generic_restore,
361};
362
363const struct bus_type host1x_bus_type = {
364	.name = "host1x",
365	.match = host1x_device_match,
366	.uevent = host1x_device_uevent,
367	.pm = &host1x_device_pm_ops,
368};
369
370static void __host1x_device_del(struct host1x_device *device)
371{
372	struct host1x_subdev *subdev, *sd;
373	struct host1x_client *client, *cl;
374
375	mutex_lock(&device->subdevs_lock);
376
377	/* unregister subdevices */
378	list_for_each_entry_safe(subdev, sd, &device->active, list) {
379		/*
380		 * host1x_subdev_unregister() will remove the client from
381		 * any lists, so we'll need to manually add it back to the
382		 * list of idle clients.
383		 *
384		 * XXX: Alternatively, perhaps don't remove the client from
385		 * any lists in host1x_subdev_unregister() and instead do
386		 * that explicitly from host1x_unregister_client()?
387		 */
388		client = subdev->client;
389
390		__host1x_subdev_unregister(device, subdev);
391
392		/* add the client to the list of idle clients */
393		mutex_lock(&clients_lock);
394		list_add_tail(&client->list, &clients);
395		mutex_unlock(&clients_lock);
396	}
397
398	/* remove subdevices */
399	list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
400		host1x_subdev_del(subdev);
401
402	mutex_unlock(&device->subdevs_lock);
403
404	/* move clients to idle list */
405	mutex_lock(&clients_lock);
406	mutex_lock(&device->clients_lock);
407
408	list_for_each_entry_safe(client, cl, &device->clients, list)
409		list_move_tail(&client->list, &clients);
410
411	mutex_unlock(&device->clients_lock);
412	mutex_unlock(&clients_lock);
413
414	/* finally remove the device */
415	list_del_init(&device->list);
416}
417
418static void host1x_device_release(struct device *dev)
419{
420	struct host1x_device *device = to_host1x_device(dev);
421
422	__host1x_device_del(device);
423	kfree(device);
424}
425
426static int host1x_device_add(struct host1x *host1x,
427			     struct host1x_driver *driver)
428{
429	struct host1x_client *client, *tmp;
430	struct host1x_subdev *subdev;
431	struct host1x_device *device;
432	int err;
433
434	device = kzalloc(sizeof(*device), GFP_KERNEL);
435	if (!device)
436		return -ENOMEM;
437
438	device_initialize(&device->dev);
439
440	mutex_init(&device->subdevs_lock);
441	INIT_LIST_HEAD(&device->subdevs);
442	INIT_LIST_HEAD(&device->active);
443	mutex_init(&device->clients_lock);
444	INIT_LIST_HEAD(&device->clients);
445	INIT_LIST_HEAD(&device->list);
446	device->driver = driver;
447
448	device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
449	device->dev.dma_mask = &device->dev.coherent_dma_mask;
450	dev_set_name(&device->dev, "%s", driver->driver.name);
451	device->dev.release = host1x_device_release;
452	device->dev.bus = &host1x_bus_type;
453	device->dev.parent = host1x->dev;
454
455	device->dev.dma_parms = &device->dma_parms;
456	dma_set_max_seg_size(&device->dev, UINT_MAX);
457
458	err = host1x_device_parse_dt(device, driver);
459	if (err < 0) {
460		kfree(device);
461		return err;
462	}
463
464	list_add_tail(&device->list, &host1x->devices);
465
466	mutex_lock(&clients_lock);
467
468	list_for_each_entry_safe(client, tmp, &clients, list) {
469		list_for_each_entry(subdev, &device->subdevs, list) {
470			if (subdev->np == client->dev->of_node) {
471				host1x_subdev_register(device, subdev, client);
472				break;
473			}
474		}
475	}
476
477	mutex_unlock(&clients_lock);
478
479	return 0;
480}
481
482/*
483 * Removes a device by first unregistering any subdevices and then removing
484 * itself from the list of devices.
485 *
486 * This function must be called with the host1x->devices_lock held.
487 */
488static void host1x_device_del(struct host1x *host1x,
489			      struct host1x_device *device)
490{
491	if (device->registered) {
492		device->registered = false;
493		device_del(&device->dev);
494	}
495
496	put_device(&device->dev);
497}
498
499static void host1x_attach_driver(struct host1x *host1x,
500				 struct host1x_driver *driver)
501{
502	struct host1x_device *device;
503	int err;
504
505	mutex_lock(&host1x->devices_lock);
506
507	list_for_each_entry(device, &host1x->devices, list) {
508		if (device->driver == driver) {
509			mutex_unlock(&host1x->devices_lock);
510			return;
511		}
512	}
513
514	err = host1x_device_add(host1x, driver);
515	if (err < 0)
516		dev_err(host1x->dev, "failed to allocate device: %d\n", err);
517
518	mutex_unlock(&host1x->devices_lock);
519}
520
521static void host1x_detach_driver(struct host1x *host1x,
522				 struct host1x_driver *driver)
523{
524	struct host1x_device *device, *tmp;
525
526	mutex_lock(&host1x->devices_lock);
527
528	list_for_each_entry_safe(device, tmp, &host1x->devices, list)
529		if (device->driver == driver)
530			host1x_device_del(host1x, device);
531
532	mutex_unlock(&host1x->devices_lock);
533}
534
535static int host1x_devices_show(struct seq_file *s, void *data)
536{
537	struct host1x *host1x = s->private;
538	struct host1x_device *device;
539
540	mutex_lock(&host1x->devices_lock);
541
542	list_for_each_entry(device, &host1x->devices, list) {
543		struct host1x_subdev *subdev;
544
545		seq_printf(s, "%s\n", dev_name(&device->dev));
546
547		mutex_lock(&device->subdevs_lock);
548
549		list_for_each_entry(subdev, &device->active, list)
550			seq_printf(s, "  %pOFf: %s\n", subdev->np,
551				   dev_name(subdev->client->dev));
552
553		list_for_each_entry(subdev, &device->subdevs, list)
554			seq_printf(s, "  %pOFf:\n", subdev->np);
555
556		mutex_unlock(&device->subdevs_lock);
557	}
558
559	mutex_unlock(&host1x->devices_lock);
560
561	return 0;
562}
563DEFINE_SHOW_ATTRIBUTE(host1x_devices);
564
565/**
566 * host1x_register() - register a host1x controller
567 * @host1x: host1x controller
568 *
569 * The host1x controller driver uses this to register a host1x controller with
570 * the infrastructure. Note that all Tegra SoC generations have only ever come
571 * with a single host1x instance, so this function is somewhat academic.
572 */
573int host1x_register(struct host1x *host1x)
574{
575	struct host1x_driver *driver;
576
577	mutex_lock(&devices_lock);
578	list_add_tail(&host1x->list, &devices);
579	mutex_unlock(&devices_lock);
580
581	mutex_lock(&drivers_lock);
582
583	list_for_each_entry(driver, &drivers, list)
584		host1x_attach_driver(host1x, driver);
585
586	mutex_unlock(&drivers_lock);
587
588	debugfs_create_file("devices", S_IRUGO, host1x->debugfs, host1x,
589			    &host1x_devices_fops);
590
591	return 0;
592}
593
594/**
595 * host1x_unregister() - unregister a host1x controller
596 * @host1x: host1x controller
597 *
598 * The host1x controller driver uses this to remove a host1x controller from
599 * the infrastructure.
600 */
601int host1x_unregister(struct host1x *host1x)
602{
603	struct host1x_driver *driver;
604
605	mutex_lock(&drivers_lock);
606
607	list_for_each_entry(driver, &drivers, list)
608		host1x_detach_driver(host1x, driver);
609
610	mutex_unlock(&drivers_lock);
611
612	mutex_lock(&devices_lock);
613	list_del_init(&host1x->list);
614	mutex_unlock(&devices_lock);
615
616	return 0;
617}
618
619static int host1x_device_probe(struct device *dev)
620{
621	struct host1x_driver *driver = to_host1x_driver(dev->driver);
622	struct host1x_device *device = to_host1x_device(dev);
623
624	if (driver->probe)
625		return driver->probe(device);
626
627	return 0;
628}
629
630static int host1x_device_remove(struct device *dev)
631{
632	struct host1x_driver *driver = to_host1x_driver(dev->driver);
633	struct host1x_device *device = to_host1x_device(dev);
634
635	if (driver->remove)
636		return driver->remove(device);
637
638	return 0;
639}
640
641static void host1x_device_shutdown(struct device *dev)
642{
643	struct host1x_driver *driver = to_host1x_driver(dev->driver);
644	struct host1x_device *device = to_host1x_device(dev);
645
646	if (driver->shutdown)
647		driver->shutdown(device);
648}
649
650/**
651 * host1x_driver_register_full() - register a host1x driver
652 * @driver: host1x driver
653 * @owner: owner module
654 *
655 * Drivers for host1x logical devices call this function to register a driver
656 * with the infrastructure. Note that since these drive logical devices, the
657 * registration of the driver actually triggers tho logical device creation.
658 * A logical device will be created for each host1x instance.
659 */
660int host1x_driver_register_full(struct host1x_driver *driver,
661				struct module *owner)
662{
663	struct host1x *host1x;
664
665	INIT_LIST_HEAD(&driver->list);
666
667	mutex_lock(&drivers_lock);
668	list_add_tail(&driver->list, &drivers);
669	mutex_unlock(&drivers_lock);
670
671	mutex_lock(&devices_lock);
672
673	list_for_each_entry(host1x, &devices, list)
674		host1x_attach_driver(host1x, driver);
675
676	mutex_unlock(&devices_lock);
677
678	driver->driver.bus = &host1x_bus_type;
679	driver->driver.owner = owner;
680	driver->driver.probe = host1x_device_probe;
681	driver->driver.remove = host1x_device_remove;
682	driver->driver.shutdown = host1x_device_shutdown;
683
684	return driver_register(&driver->driver);
685}
686EXPORT_SYMBOL(host1x_driver_register_full);
687
688/**
689 * host1x_driver_unregister() - unregister a host1x driver
690 * @driver: host1x driver
691 *
692 * Unbinds the driver from each of the host1x logical devices that it is
693 * bound to, effectively removing the subsystem devices that they represent.
694 */
695void host1x_driver_unregister(struct host1x_driver *driver)
696{
697	struct host1x *host1x;
698
699	driver_unregister(&driver->driver);
700
701	mutex_lock(&devices_lock);
702
703	list_for_each_entry(host1x, &devices, list)
704		host1x_detach_driver(host1x, driver);
705
706	mutex_unlock(&devices_lock);
707
708	mutex_lock(&drivers_lock);
709	list_del_init(&driver->list);
710	mutex_unlock(&drivers_lock);
711}
712EXPORT_SYMBOL(host1x_driver_unregister);
713
714/**
715 * __host1x_client_init() - initialize a host1x client
716 * @client: host1x client
717 * @key: lock class key for the client-specific mutex
718 */
719void __host1x_client_init(struct host1x_client *client, struct lock_class_key *key)
720{
721	host1x_bo_cache_init(&client->cache);
722	INIT_LIST_HEAD(&client->list);
723	__mutex_init(&client->lock, "host1x client lock", key);
724	client->usecount = 0;
725}
726EXPORT_SYMBOL(__host1x_client_init);
727
728/**
729 * host1x_client_exit() - uninitialize a host1x client
730 * @client: host1x client
731 */
732void host1x_client_exit(struct host1x_client *client)
733{
734	mutex_destroy(&client->lock);
735}
736EXPORT_SYMBOL(host1x_client_exit);
737
738/**
739 * __host1x_client_register() - register a host1x client
740 * @client: host1x client
741 *
742 * Registers a host1x client with each host1x controller instance. Note that
743 * each client will only match their parent host1x controller and will only be
744 * associated with that instance. Once all clients have been registered with
745 * their parent host1x controller, the infrastructure will set up the logical
746 * device and call host1x_device_init(), which will in turn call each client's
747 * &host1x_client_ops.init implementation.
748 */
749int __host1x_client_register(struct host1x_client *client)
750{
751	struct host1x *host1x;
752	int err;
753
754	mutex_lock(&devices_lock);
755
756	list_for_each_entry(host1x, &devices, list) {
757		err = host1x_add_client(host1x, client);
758		if (!err) {
759			mutex_unlock(&devices_lock);
760			return 0;
761		}
762	}
763
764	mutex_unlock(&devices_lock);
765
766	mutex_lock(&clients_lock);
767	list_add_tail(&client->list, &clients);
768	mutex_unlock(&clients_lock);
769
770	return 0;
771}
772EXPORT_SYMBOL(__host1x_client_register);
773
774/**
775 * host1x_client_unregister() - unregister a host1x client
776 * @client: host1x client
777 *
778 * Removes a host1x client from its host1x controller instance. If a logical
779 * device has already been initialized, it will be torn down.
780 */
781void host1x_client_unregister(struct host1x_client *client)
782{
783	struct host1x_client *c;
784	struct host1x *host1x;
785	int err;
786
787	mutex_lock(&devices_lock);
788
789	list_for_each_entry(host1x, &devices, list) {
790		err = host1x_del_client(host1x, client);
791		if (!err) {
792			mutex_unlock(&devices_lock);
793			return;
794		}
795	}
796
797	mutex_unlock(&devices_lock);
798	mutex_lock(&clients_lock);
799
800	list_for_each_entry(c, &clients, list) {
801		if (c == client) {
802			list_del_init(&c->list);
803			break;
804		}
805	}
806
807	mutex_unlock(&clients_lock);
808
809	host1x_bo_cache_destroy(&client->cache);
810}
811EXPORT_SYMBOL(host1x_client_unregister);
812
813int host1x_client_suspend(struct host1x_client *client)
814{
815	int err = 0;
816
817	mutex_lock(&client->lock);
818
819	if (client->usecount == 1) {
820		if (client->ops && client->ops->suspend) {
821			err = client->ops->suspend(client);
822			if (err < 0)
823				goto unlock;
824		}
825	}
826
827	client->usecount--;
828	dev_dbg(client->dev, "use count: %u\n", client->usecount);
829
830	if (client->parent) {
831		err = host1x_client_suspend(client->parent);
832		if (err < 0)
833			goto resume;
834	}
835
836	goto unlock;
837
838resume:
839	if (client->usecount == 0)
840		if (client->ops && client->ops->resume)
841			client->ops->resume(client);
842
843	client->usecount++;
844unlock:
845	mutex_unlock(&client->lock);
846	return err;
847}
848EXPORT_SYMBOL(host1x_client_suspend);
849
850int host1x_client_resume(struct host1x_client *client)
851{
852	int err = 0;
853
854	mutex_lock(&client->lock);
855
856	if (client->parent) {
857		err = host1x_client_resume(client->parent);
858		if (err < 0)
859			goto unlock;
860	}
861
862	if (client->usecount == 0) {
863		if (client->ops && client->ops->resume) {
864			err = client->ops->resume(client);
865			if (err < 0)
866				goto suspend;
867		}
868	}
869
870	client->usecount++;
871	dev_dbg(client->dev, "use count: %u\n", client->usecount);
872
873	goto unlock;
874
875suspend:
876	if (client->parent)
877		host1x_client_suspend(client->parent);
878unlock:
879	mutex_unlock(&client->lock);
880	return err;
881}
882EXPORT_SYMBOL(host1x_client_resume);
883
884struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
885					enum dma_data_direction dir,
886					struct host1x_bo_cache *cache)
887{
888	struct host1x_bo_mapping *mapping;
889
890	if (cache) {
891		mutex_lock(&cache->lock);
892
893		list_for_each_entry(mapping, &cache->mappings, entry) {
894			if (mapping->bo == bo && mapping->direction == dir) {
895				kref_get(&mapping->ref);
896				goto unlock;
897			}
898		}
899	}
900
901	mapping = bo->ops->pin(dev, bo, dir);
902	if (IS_ERR(mapping))
903		goto unlock;
904
905	spin_lock(&mapping->bo->lock);
906	list_add_tail(&mapping->list, &bo->mappings);
907	spin_unlock(&mapping->bo->lock);
908
909	if (cache) {
910		INIT_LIST_HEAD(&mapping->entry);
911		mapping->cache = cache;
912
913		list_add_tail(&mapping->entry, &cache->mappings);
914
915		/* bump reference count to track the copy in the cache */
916		kref_get(&mapping->ref);
917	}
918
919unlock:
920	if (cache)
921		mutex_unlock(&cache->lock);
922
923	return mapping;
924}
925EXPORT_SYMBOL(host1x_bo_pin);
926
927static void __host1x_bo_unpin(struct kref *ref)
928{
929	struct host1x_bo_mapping *mapping = to_host1x_bo_mapping(ref);
930
931	/*
932	 * When the last reference of the mapping goes away, make sure to remove the mapping from
933	 * the cache.
934	 */
935	if (mapping->cache)
936		list_del(&mapping->entry);
937
938	spin_lock(&mapping->bo->lock);
939	list_del(&mapping->list);
940	spin_unlock(&mapping->bo->lock);
941
942	mapping->bo->ops->unpin(mapping);
943}
944
945void host1x_bo_unpin(struct host1x_bo_mapping *mapping)
946{
947	struct host1x_bo_cache *cache = mapping->cache;
948
949	if (cache)
950		mutex_lock(&cache->lock);
951
952	kref_put(&mapping->ref, __host1x_bo_unpin);
953
954	if (cache)
955		mutex_unlock(&cache->lock);
956}
957EXPORT_SYMBOL(host1x_bo_unpin);
958