gpu/host1x/bus.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2012 Avionic Design GmbH
0004  * Copyright (C) 2012-2013, NVIDIA Corporation
0005  */
0006
0007 #include <linux/debugfs.h>
0008 #include <linux/dma-mapping.h>
0009 #include <linux/host1x.h>
0010 #include <linux/of.h>
0011 #include <linux/seq_file.h>
0012 #include <linux/slab.h>
0013 #include <linux/of_device.h>
0014
0015 #include "bus.h"
0016 #include "dev.h"
0017
0018 static DEFINE_MUTEX(clients_lock);
0019 static LIST_HEAD(clients);
0020
0021 static DEFINE_MUTEX(drivers_lock);
0022 static LIST_HEAD(drivers);
0023
0024 static DEFINE_MUTEX(devices_lock);
0025 static LIST_HEAD(devices);
0026
0027 struct host1x_subdev {
0028     struct host1x_client *client;
0029     struct device_node *np;
0030     struct list_head list;
0031 };
0032
0033 /**
0034  * host1x_subdev_add() - add a new subdevice with an associated device node
0035  * @device: host1x device to add the subdevice to
0036  * @driver: host1x driver containing the subdevices
0037  * @np: device node
0038  */
0039 static int host1x_subdev_add(struct host1x_device *device,
0040                  struct host1x_driver *driver,
0041                  struct device_node *np)
0042 {
0043     struct host1x_subdev *subdev;
0044     struct device_node *child;
0045     int err;
0046
0047     subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
0048     if (!subdev)
0049         return -ENOMEM;
0050
0051     INIT_LIST_HEAD(&subdev->list);
0052     subdev->np = of_node_get(np);
0053
0054     mutex_lock(&device->subdevs_lock);
0055     list_add_tail(&subdev->list, &device->subdevs);
0056     mutex_unlock(&device->subdevs_lock);
0057
0058     /* recursively add children */
0059     for_each_child_of_node(np, child) {
0060         if (of_match_node(driver->subdevs, child) &&
0061             of_device_is_available(child)) {
0062             err = host1x_subdev_add(device, driver, child);
0063             if (err < 0) {
0064                 /* XXX cleanup? */
0065                 of_node_put(child);
0066                 return err;
0067             }
0068         }
0069     }
0070
0071     return 0;
0072 }
0073
0074 /**
0075  * host1x_subdev_del() - remove subdevice
0076  * @subdev: subdevice to remove
0077  */
0078 static void host1x_subdev_del(struct host1x_subdev *subdev)
0079 {
0080     list_del(&subdev->list);
0081     of_node_put(subdev->np);
0082     kfree(subdev);
0083 }
0084
0085 /**
0086  * host1x_device_parse_dt() - scan device tree and add matching subdevices
0087  * @device: host1x logical device
0088  * @driver: host1x driver
0089  */
0090 static int host1x_device_parse_dt(struct host1x_device *device,
0091                   struct host1x_driver *driver)
0092 {
0093     struct device_node *np;
0094     int err;
0095
0096     for_each_child_of_node(device->dev.parent->of_node, np) {
0097         if (of_match_node(driver->subdevs, np) &&
0098             of_device_is_available(np)) {
0099             err = host1x_subdev_add(device, driver, np);
0100             if (err < 0) {
0101                 of_node_put(np);
0102                 return err;
0103             }
0104         }
0105     }
0106
0107     return 0;
0108 }
0109
0110 static void host1x_subdev_register(struct host1x_device *device,
0111                    struct host1x_subdev *subdev,
0112                    struct host1x_client *client)
0113 {
0114     int err;
0115
0116     /*
0117      * Move the subdevice to the list of active (registered) subdevices
0118      * and associate it with a client. At the same time, associate the
0119      * client with its parent device.
0120      */
0121     mutex_lock(&device->subdevs_lock);
0122     mutex_lock(&device->clients_lock);
0123     list_move_tail(&client->list, &device->clients);
0124     list_move_tail(&subdev->list, &device->active);
0125     client->host = &device->dev;
0126     subdev->client = client;
0127     mutex_unlock(&device->clients_lock);
0128     mutex_unlock(&device->subdevs_lock);
0129
0130     if (list_empty(&device->subdevs)) {
0131         err = device_add(&device->dev);
0132         if (err < 0)
0133             dev_err(&device->dev, "failed to add: %d\n", err);
0134         else
0135             device->registered = true;
0136     }
0137 }
0138
0139 static void __host1x_subdev_unregister(struct host1x_device *device,
0140                        struct host1x_subdev *subdev)
0141 {
0142     struct host1x_client *client = subdev->client;
0143
0144     /*
0145      * If all subdevices have been activated, we're about to remove the
0146      * first active subdevice, so unload the driver first.
0147      */
0148     if (list_empty(&device->subdevs)) {
0149         if (device->registered) {
0150             device->registered = false;
0151             device_del(&device->dev);
0152         }
0153     }
0154
0155     /*
0156      * Move the subdevice back to the list of idle subdevices and remove
0157      * it from list of clients.
0158      */
0159     mutex_lock(&device->clients_lock);
0160     subdev->client = NULL;
0161     client->host = NULL;
0162     list_move_tail(&subdev->list, &device->subdevs);
0163     /*
0164      * XXX: Perhaps don't do this here, but rather explicitly remove it
0165      * when the device is about to be deleted.
0166      *
0167      * This is somewhat complicated by the fact that this function is
0168      * used to remove the subdevice when a client is unregistered but
0169      * also when the composite device is about to be removed.
0170      */
0171     list_del_init(&client->list);
0172     mutex_unlock(&device->clients_lock);
0173 }
0174
0175 static void host1x_subdev_unregister(struct host1x_device *device,
0176                      struct host1x_subdev *subdev)
0177 {
0178     mutex_lock(&device->subdevs_lock);
0179     __host1x_subdev_unregister(device, subdev);
0180     mutex_unlock(&device->subdevs_lock);
0181 }
0182
0183 /**
0184  * host1x_device_init() - initialize a host1x logical device
0185  * @device: host1x logical device
0186  *
0187  * The driver for the host1x logical device can call this during execution of
0188  * its &host1x_driver.probe implementation to initialize each of its clients.
0189  * The client drivers access the subsystem specific driver data using the
0190  * &host1x_client.parent field and driver data associated with it (usually by
0191  * calling dev_get_drvdata()).
0192  */
0193 int host1x_device_init(struct host1x_device *device)
0194 {
0195     struct host1x_client *client;
0196     int err;
0197
0198     mutex_lock(&device->clients_lock);
0199
0200     list_for_each_entry(client, &device->clients, list) {
0201         if (client->ops && client->ops->early_init) {
0202             err = client->ops->early_init(client);
0203             if (err < 0) {
0204                 dev_err(&device->dev, "failed to early initialize %s: %d\n",
0205                     dev_name(client->dev), err);
0206                 goto teardown_late;
0207             }
0208         }
0209     }
0210
0211     list_for_each_entry(client, &device->clients, list) {
0212         if (client->ops && client->ops->init) {
0213             err = client->ops->init(client);
0214             if (err < 0) {
0215                 dev_err(&device->dev,
0216                     "failed to initialize %s: %d\n",
0217                     dev_name(client->dev), err);
0218                 goto teardown;
0219             }
0220         }
0221     }
0222
0223     mutex_unlock(&device->clients_lock);
0224
0225     return 0;
0226
0227 teardown:
0228     list_for_each_entry_continue_reverse(client, &device->clients, list)
0229         if (client->ops->exit)
0230             client->ops->exit(client);
0231
0232     /* reset client to end of list for late teardown */
0233     client = list_entry(&device->clients, struct host1x_client, list);
0234
0235 teardown_late:
0236     list_for_each_entry_continue_reverse(client, &device->clients, list)
0237         if (client->ops->late_exit)
0238             client->ops->late_exit(client);
0239
0240     mutex_unlock(&device->clients_lock);
0241     return err;
0242 }
0243 EXPORT_SYMBOL(host1x_device_init);
0244
0245 /**
0246  * host1x_device_exit() - uninitialize host1x logical device
0247  * @device: host1x logical device
0248  *
0249  * When the driver for a host1x logical device is unloaded, it can call this
0250  * function to tear down each of its clients. Typically this is done after a
0251  * subsystem-specific data structure is removed and the functionality can no
0252  * longer be used.
0253  */
0254 int host1x_device_exit(struct host1x_device *device)
0255 {
0256     struct host1x_client *client;
0257     int err;
0258
0259     mutex_lock(&device->clients_lock);
0260
0261     list_for_each_entry_reverse(client, &device->clients, list) {
0262         if (client->ops && client->ops->exit) {
0263             err = client->ops->exit(client);
0264             if (err < 0) {
0265                 dev_err(&device->dev,
0266                     "failed to cleanup %s: %d\n",
0267                     dev_name(client->dev), err);
0268                 mutex_unlock(&device->clients_lock);
0269                 return err;
0270             }
0271         }
0272     }
0273
0274     list_for_each_entry_reverse(client, &device->clients, list) {
0275         if (client->ops && client->ops->late_exit) {
0276             err = client->ops->late_exit(client);
0277             if (err < 0) {
0278                 dev_err(&device->dev, "failed to late cleanup %s: %d\n",
0279                     dev_name(client->dev), err);
0280                 mutex_unlock(&device->clients_lock);
0281                 return err;
0282             }
0283         }
0284     }
0285
0286     mutex_unlock(&device->clients_lock);
0287
0288     return 0;
0289 }
0290 EXPORT_SYMBOL(host1x_device_exit);
0291
0292 static int host1x_add_client(struct host1x *host1x,
0293                  struct host1x_client *client)
0294 {
0295     struct host1x_device *device;
0296     struct host1x_subdev *subdev;
0297
0298     mutex_lock(&host1x->devices_lock);
0299
0300     list_for_each_entry(device, &host1x->devices, list) {
0301         list_for_each_entry(subdev, &device->subdevs, list) {
0302             if (subdev->np == client->dev->of_node) {
0303                 host1x_subdev_register(device, subdev, client);
0304                 mutex_unlock(&host1x->devices_lock);
0305                 return 0;
0306             }
0307         }
0308     }
0309
0310     mutex_unlock(&host1x->devices_lock);
0311     return -ENODEV;
0312 }
0313
0314 static int host1x_del_client(struct host1x *host1x,
0315                  struct host1x_client *client)
0316 {
0317     struct host1x_device *device, *dt;
0318     struct host1x_subdev *subdev;
0319
0320     mutex_lock(&host1x->devices_lock);
0321
0322     list_for_each_entry_safe(device, dt, &host1x->devices, list) {
0323         list_for_each_entry(subdev, &device->active, list) {
0324             if (subdev->client == client) {
0325                 host1x_subdev_unregister(device, subdev);
0326                 mutex_unlock(&host1x->devices_lock);
0327                 return 0;
0328             }
0329         }
0330     }
0331
0332     mutex_unlock(&host1x->devices_lock);
0333     return -ENODEV;
0334 }
0335
0336 static int host1x_device_match(struct device *dev, struct device_driver *drv)
0337 {
0338     return strcmp(dev_name(dev), drv->name) == 0;
0339 }
0340
0341 static int host1x_device_uevent(struct device *dev,
0342                 struct kobj_uevent_env *env)
0343 {
0344     struct device_node *np = dev->parent->of_node;
0345     unsigned int count = 0;
0346     struct property *p;
0347     const char *compat;
0348
0349     /*
0350      * This duplicates most of of_device_uevent(), but the latter cannot
0351      * be called from modules and operates on dev->of_node, which is not
0352      * available in this case.
0353      *
0354      * Note that this is really only needed for backwards compatibility
0355      * with libdrm, which parses this information from sysfs and will
0356      * fail if it can't find the OF_FULLNAME, specifically.
0357      */
0358     add_uevent_var(env, "OF_NAME=%pOFn", np);
0359     add_uevent_var(env, "OF_FULLNAME=%pOF", np);
0360
0361     of_property_for_each_string(np, "compatible", p, compat) {
0362         add_uevent_var(env, "OF_COMPATIBLE_%u=%s", count, compat);
0363         count++;
0364     }
0365
0366     add_uevent_var(env, "OF_COMPATIBLE_N=%u", count);
0367
0368     return 0;
0369 }
0370
0371 static int host1x_dma_configure(struct device *dev)
0372 {
0373     return of_dma_configure(dev, dev->of_node, true);
0374 }
0375
0376 static const struct dev_pm_ops host1x_device_pm_ops = {
0377     .suspend = pm_generic_suspend,
0378     .resume = pm_generic_resume,
0379     .freeze = pm_generic_freeze,
0380     .thaw = pm_generic_thaw,
0381     .poweroff = pm_generic_poweroff,
0382     .restore = pm_generic_restore,
0383 };
0384
0385 struct bus_type host1x_bus_type = {
0386     .name = "host1x",
0387     .match = host1x_device_match,
0388     .uevent = host1x_device_uevent,
0389     .dma_configure = host1x_dma_configure,
0390     .pm = &host1x_device_pm_ops,
0391 };
0392
0393 static void __host1x_device_del(struct host1x_device *device)
0394 {
0395     struct host1x_subdev *subdev, *sd;
0396     struct host1x_client *client, *cl;
0397
0398     mutex_lock(&device->subdevs_lock);
0399
0400     /* unregister subdevices */
0401     list_for_each_entry_safe(subdev, sd, &device->active, list) {
0402         /*
0403          * host1x_subdev_unregister() will remove the client from
0404          * any lists, so we'll need to manually add it back to the
0405          * list of idle clients.
0406          *
0407          * XXX: Alternatively, perhaps don't remove the client from
0408          * any lists in host1x_subdev_unregister() and instead do
0409          * that explicitly from host1x_unregister_client()?
0410          */
0411         client = subdev->client;
0412
0413         __host1x_subdev_unregister(device, subdev);
0414
0415         /* add the client to the list of idle clients */
0416         mutex_lock(&clients_lock);
0417         list_add_tail(&client->list, &clients);
0418         mutex_unlock(&clients_lock);
0419     }
0420
0421     /* remove subdevices */
0422     list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
0423         host1x_subdev_del(subdev);
0424
0425     mutex_unlock(&device->subdevs_lock);
0426
0427     /* move clients to idle list */
0428     mutex_lock(&clients_lock);
0429     mutex_lock(&device->clients_lock);
0430
0431     list_for_each_entry_safe(client, cl, &device->clients, list)
0432         list_move_tail(&client->list, &clients);
0433
0434     mutex_unlock(&device->clients_lock);
0435     mutex_unlock(&clients_lock);
0436
0437     /* finally remove the device */
0438     list_del_init(&device->list);
0439 }
0440
0441 static void host1x_device_release(struct device *dev)
0442 {
0443     struct host1x_device *device = to_host1x_device(dev);
0444
0445     __host1x_device_del(device);
0446     kfree(device);
0447 }
0448
0449 static int host1x_device_add(struct host1x *host1x,
0450                  struct host1x_driver *driver)
0451 {
0452     struct host1x_client *client, *tmp;
0453     struct host1x_subdev *subdev;
0454     struct host1x_device *device;
0455     int err;
0456
0457     device = kzalloc(sizeof(*device), GFP_KERNEL);
0458     if (!device)
0459         return -ENOMEM;
0460
0461     device_initialize(&device->dev);
0462
0463     mutex_init(&device->subdevs_lock);
0464     INIT_LIST_HEAD(&device->subdevs);
0465     INIT_LIST_HEAD(&device->active);
0466     mutex_init(&device->clients_lock);
0467     INIT_LIST_HEAD(&device->clients);
0468     INIT_LIST_HEAD(&device->list);
0469     device->driver = driver;
0470
0471     device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
0472     device->dev.dma_mask = &device->dev.coherent_dma_mask;
0473     dev_set_name(&device->dev, "%s", driver->driver.name);
0474     device->dev.release = host1x_device_release;
0475     device->dev.bus = &host1x_bus_type;
0476     device->dev.parent = host1x->dev;
0477
0478     of_dma_configure(&device->dev, host1x->dev->of_node, true);
0479
0480     device->dev.dma_parms = &device->dma_parms;
0481     dma_set_max_seg_size(&device->dev, UINT_MAX);
0482
0483     err = host1x_device_parse_dt(device, driver);
0484     if (err < 0) {
0485         kfree(device);
0486         return err;
0487     }
0488
0489     list_add_tail(&device->list, &host1x->devices);
0490
0491     mutex_lock(&clients_lock);
0492
0493     list_for_each_entry_safe(client, tmp, &clients, list) {
0494         list_for_each_entry(subdev, &device->subdevs, list) {
0495             if (subdev->np == client->dev->of_node) {
0496                 host1x_subdev_register(device, subdev, client);
0497                 break;
0498             }
0499         }
0500     }
0501
0502     mutex_unlock(&clients_lock);
0503
0504     return 0;
0505 }
0506
0507 /*
0508  * Removes a device by first unregistering any subdevices and then removing
0509  * itself from the list of devices.
0510  *
0511  * This function must be called with the host1x->devices_lock held.
0512  */
0513 static void host1x_device_del(struct host1x *host1x,
0514                   struct host1x_device *device)
0515 {
0516     if (device->registered) {
0517         device->registered = false;
0518         device_del(&device->dev);
0519     }
0520
0521     put_device(&device->dev);
0522 }
0523
0524 static void host1x_attach_driver(struct host1x *host1x,
0525                  struct host1x_driver *driver)
0526 {
0527     struct host1x_device *device;
0528     int err;
0529
0530     mutex_lock(&host1x->devices_lock);
0531
0532     list_for_each_entry(device, &host1x->devices, list) {
0533         if (device->driver == driver) {
0534             mutex_unlock(&host1x->devices_lock);
0535             return;
0536         }
0537     }
0538
0539     err = host1x_device_add(host1x, driver);
0540     if (err < 0)
0541         dev_err(host1x->dev, "failed to allocate device: %d\n", err);
0542
0543     mutex_unlock(&host1x->devices_lock);
0544 }
0545
0546 static void host1x_detach_driver(struct host1x *host1x,
0547                  struct host1x_driver *driver)
0548 {
0549     struct host1x_device *device, *tmp;
0550
0551     mutex_lock(&host1x->devices_lock);
0552
0553     list_for_each_entry_safe(device, tmp, &host1x->devices, list)
0554         if (device->driver == driver)
0555             host1x_device_del(host1x, device);
0556
0557     mutex_unlock(&host1x->devices_lock);
0558 }
0559
0560 static int host1x_devices_show(struct seq_file *s, void *data)
0561 {
0562     struct host1x *host1x = s->private;
0563     struct host1x_device *device;
0564
0565     mutex_lock(&host1x->devices_lock);
0566
0567     list_for_each_entry(device, &host1x->devices, list) {
0568         struct host1x_subdev *subdev;
0569
0570         seq_printf(s, "%s\n", dev_name(&device->dev));
0571
0572         mutex_lock(&device->subdevs_lock);
0573
0574         list_for_each_entry(subdev, &device->active, list)
0575             seq_printf(s, "  %pOFf: %s\n", subdev->np,
0576                    dev_name(subdev->client->dev));
0577
0578         list_for_each_entry(subdev, &device->subdevs, list)
0579             seq_printf(s, "  %pOFf:\n", subdev->np);
0580
0581         mutex_unlock(&device->subdevs_lock);
0582     }
0583
0584     mutex_unlock(&host1x->devices_lock);
0585
0586     return 0;
0587 }
0588 DEFINE_SHOW_ATTRIBUTE(host1x_devices);
0589
0590 /**
0591  * host1x_register() - register a host1x controller
0592  * @host1x: host1x controller
0593  *
0594  * The host1x controller driver uses this to register a host1x controller with
0595  * the infrastructure. Note that all Tegra SoC generations have only ever come
0596  * with a single host1x instance, so this function is somewhat academic.
0597  */
0598 int host1x_register(struct host1x *host1x)
0599 {
0600     struct host1x_driver *driver;
0601
0602     mutex_lock(&devices_lock);
0603     list_add_tail(&host1x->list, &devices);
0604     mutex_unlock(&devices_lock);
0605
0606     mutex_lock(&drivers_lock);
0607
0608     list_for_each_entry(driver, &drivers, list)
0609         host1x_attach_driver(host1x, driver);
0610
0611     mutex_unlock(&drivers_lock);
0612
0613     debugfs_create_file("devices", S_IRUGO, host1x->debugfs, host1x,
0614                 &host1x_devices_fops);
0615
0616     return 0;
0617 }
0618
0619 /**
0620  * host1x_unregister() - unregister a host1x controller
0621  * @host1x: host1x controller
0622  *
0623  * The host1x controller driver uses this to remove a host1x controller from
0624  * the infrastructure.
0625  */
0626 int host1x_unregister(struct host1x *host1x)
0627 {
0628     struct host1x_driver *driver;
0629
0630     mutex_lock(&drivers_lock);
0631
0632     list_for_each_entry(driver, &drivers, list)
0633         host1x_detach_driver(host1x, driver);
0634
0635     mutex_unlock(&drivers_lock);
0636
0637     mutex_lock(&devices_lock);
0638     list_del_init(&host1x->list);
0639     mutex_unlock(&devices_lock);
0640
0641     return 0;
0642 }
0643
0644 static int host1x_device_probe(struct device *dev)
0645 {
0646     struct host1x_driver *driver = to_host1x_driver(dev->driver);
0647     struct host1x_device *device = to_host1x_device(dev);
0648
0649     if (driver->probe)
0650         return driver->probe(device);
0651
0652     return 0;
0653 }
0654
0655 static int host1x_device_remove(struct device *dev)
0656 {
0657     struct host1x_driver *driver = to_host1x_driver(dev->driver);
0658     struct host1x_device *device = to_host1x_device(dev);
0659
0660     if (driver->remove)
0661         return driver->remove(device);
0662
0663     return 0;
0664 }
0665
0666 static void host1x_device_shutdown(struct device *dev)
0667 {
0668     struct host1x_driver *driver = to_host1x_driver(dev->driver);
0669     struct host1x_device *device = to_host1x_device(dev);
0670
0671     if (driver->shutdown)
0672         driver->shutdown(device);
0673 }
0674
0675 /**
0676  * host1x_driver_register_full() - register a host1x driver
0677  * @driver: host1x driver
0678  * @owner: owner module
0679  *
0680  * Drivers for host1x logical devices call this function to register a driver
0681  * with the infrastructure. Note that since these drive logical devices, the
0682  * registration of the driver actually triggers tho logical device creation.
0683  * A logical device will be created for each host1x instance.
0684  */
0685 int host1x_driver_register_full(struct host1x_driver *driver,
0686                 struct module *owner)
0687 {
0688     struct host1x *host1x;
0689
0690     INIT_LIST_HEAD(&driver->list);
0691
0692     mutex_lock(&drivers_lock);
0693     list_add_tail(&driver->list, &drivers);
0694     mutex_unlock(&drivers_lock);
0695
0696     mutex_lock(&devices_lock);
0697
0698     list_for_each_entry(host1x, &devices, list)
0699         host1x_attach_driver(host1x, driver);
0700
0701     mutex_unlock(&devices_lock);
0702
0703     driver->driver.bus = &host1x_bus_type;
0704     driver->driver.owner = owner;
0705     driver->driver.probe = host1x_device_probe;
0706     driver->driver.remove = host1x_device_remove;
0707     driver->driver.shutdown = host1x_device_shutdown;
0708
0709     return driver_register(&driver->driver);
0710 }
0711 EXPORT_SYMBOL(host1x_driver_register_full);
0712
0713 /**
0714  * host1x_driver_unregister() - unregister a host1x driver
0715  * @driver: host1x driver
0716  *
0717  * Unbinds the driver from each of the host1x logical devices that it is
0718  * bound to, effectively removing the subsystem devices that they represent.
0719  */
0720 void host1x_driver_unregister(struct host1x_driver *driver)
0721 {
0722     struct host1x *host1x;
0723
0724     driver_unregister(&driver->driver);
0725
0726     mutex_lock(&devices_lock);
0727
0728     list_for_each_entry(host1x, &devices, list)
0729         host1x_detach_driver(host1x, driver);
0730
0731     mutex_unlock(&devices_lock);
0732
0733     mutex_lock(&drivers_lock);
0734     list_del_init(&driver->list);
0735     mutex_unlock(&drivers_lock);
0736 }
0737 EXPORT_SYMBOL(host1x_driver_unregister);
0738
0739 /**
0740  * __host1x_client_init() - initialize a host1x client
0741  * @client: host1x client
0742  * @key: lock class key for the client-specific mutex
0743  */
0744 void __host1x_client_init(struct host1x_client *client, struct lock_class_key *key)
0745 {
0746     host1x_bo_cache_init(&client->cache);
0747     INIT_LIST_HEAD(&client->list);
0748     __mutex_init(&client->lock, "host1x client lock", key);
0749     client->usecount = 0;
0750 }
0751 EXPORT_SYMBOL(__host1x_client_init);
0752
0753 /**
0754  * host1x_client_exit() - uninitialize a host1x client
0755  * @client: host1x client
0756  */
0757 void host1x_client_exit(struct host1x_client *client)
0758 {
0759     mutex_destroy(&client->lock);
0760 }
0761 EXPORT_SYMBOL(host1x_client_exit);
0762
0763 /**
0764  * __host1x_client_register() - register a host1x client
0765  * @client: host1x client
0766  *
0767  * Registers a host1x client with each host1x controller instance. Note that
0768  * each client will only match their parent host1x controller and will only be
0769  * associated with that instance. Once all clients have been registered with
0770  * their parent host1x controller, the infrastructure will set up the logical
0771  * device and call host1x_device_init(), which will in turn call each client's
0772  * &host1x_client_ops.init implementation.
0773  */
0774 int __host1x_client_register(struct host1x_client *client)
0775 {
0776     struct host1x *host1x;
0777     int err;
0778
0779     mutex_lock(&devices_lock);
0780
0781     list_for_each_entry(host1x, &devices, list) {
0782         err = host1x_add_client(host1x, client);
0783         if (!err) {
0784             mutex_unlock(&devices_lock);
0785             return 0;
0786         }
0787     }
0788
0789     mutex_unlock(&devices_lock);
0790
0791     mutex_lock(&clients_lock);
0792     list_add_tail(&client->list, &clients);
0793     mutex_unlock(&clients_lock);
0794
0795     return 0;
0796 }
0797 EXPORT_SYMBOL(__host1x_client_register);
0798
0799 /**
0800  * host1x_client_unregister() - unregister a host1x client
0801  * @client: host1x client
0802  *
0803  * Removes a host1x client from its host1x controller instance. If a logical
0804  * device has already been initialized, it will be torn down.
0805  */
0806 int host1x_client_unregister(struct host1x_client *client)
0807 {
0808     struct host1x_client *c;
0809     struct host1x *host1x;
0810     int err;
0811
0812     mutex_lock(&devices_lock);
0813
0814     list_for_each_entry(host1x, &devices, list) {
0815         err = host1x_del_client(host1x, client);
0816         if (!err) {
0817             mutex_unlock(&devices_lock);
0818             return 0;
0819         }
0820     }
0821
0822     mutex_unlock(&devices_lock);
0823     mutex_lock(&clients_lock);
0824
0825     list_for_each_entry(c, &clients, list) {
0826         if (c == client) {
0827             list_del_init(&c->list);
0828             break;
0829         }
0830     }
0831
0832     mutex_unlock(&clients_lock);
0833
0834     host1x_bo_cache_destroy(&client->cache);
0835
0836     return 0;
0837 }
0838 EXPORT_SYMBOL(host1x_client_unregister);
0839
0840 int host1x_client_suspend(struct host1x_client *client)
0841 {
0842     int err = 0;
0843
0844     mutex_lock(&client->lock);
0845
0846     if (client->usecount == 1) {
0847         if (client->ops && client->ops->suspend) {
0848             err = client->ops->suspend(client);
0849             if (err < 0)
0850                 goto unlock;
0851         }
0852     }
0853
0854     client->usecount--;
0855     dev_dbg(client->dev, "use count: %u\n", client->usecount);
0856
0857     if (client->parent) {
0858         err = host1x_client_suspend(client->parent);
0859         if (err < 0)
0860             goto resume;
0861     }
0862
0863     goto unlock;
0864
0865 resume:
0866     if (client->usecount == 0)
0867         if (client->ops && client->ops->resume)
0868             client->ops->resume(client);
0869
0870     client->usecount++;
0871 unlock:
0872     mutex_unlock(&client->lock);
0873     return err;
0874 }
0875 EXPORT_SYMBOL(host1x_client_suspend);
0876
0877 int host1x_client_resume(struct host1x_client *client)
0878 {
0879     int err = 0;
0880
0881     mutex_lock(&client->lock);
0882
0883     if (client->parent) {
0884         err = host1x_client_resume(client->parent);
0885         if (err < 0)
0886             goto unlock;
0887     }
0888
0889     if (client->usecount == 0) {
0890         if (client->ops && client->ops->resume) {
0891             err = client->ops->resume(client);
0892             if (err < 0)
0893                 goto suspend;
0894         }
0895     }
0896
0897     client->usecount++;
0898     dev_dbg(client->dev, "use count: %u\n", client->usecount);
0899
0900     goto unlock;
0901
0902 suspend:
0903     if (client->parent)
0904         host1x_client_suspend(client->parent);
0905 unlock:
0906     mutex_unlock(&client->lock);
0907     return err;
0908 }
0909 EXPORT_SYMBOL(host1x_client_resume);
0910
0911 struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
0912                     enum dma_data_direction dir,
0913                     struct host1x_bo_cache *cache)
0914 {
0915     struct host1x_bo_mapping *mapping;
0916
0917     if (cache) {
0918         mutex_lock(&cache->lock);
0919
0920         list_for_each_entry(mapping, &cache->mappings, entry) {
0921             if (mapping->bo == bo && mapping->direction == dir) {
0922                 kref_get(&mapping->ref);
0923                 goto unlock;
0924             }
0925         }
0926     }
0927
0928     mapping = bo->ops->pin(dev, bo, dir);
0929     if (IS_ERR(mapping))
0930         goto unlock;
0931
0932     spin_lock(&mapping->bo->lock);
0933     list_add_tail(&mapping->list, &bo->mappings);
0934     spin_unlock(&mapping->bo->lock);
0935
0936     if (cache) {
0937         INIT_LIST_HEAD(&mapping->entry);
0938         mapping->cache = cache;
0939
0940         list_add_tail(&mapping->entry, &cache->mappings);
0941
0942         /* bump reference count to track the copy in the cache */
0943         kref_get(&mapping->ref);
0944     }
0945
0946 unlock:
0947     if (cache)
0948         mutex_unlock(&cache->lock);
0949
0950     return mapping;
0951 }
0952 EXPORT_SYMBOL(host1x_bo_pin);
0953
0954 static void __host1x_bo_unpin(struct kref *ref)
0955 {
0956     struct host1x_bo_mapping *mapping = to_host1x_bo_mapping(ref);
0957
0958     /*
0959      * When the last reference of the mapping goes away, make sure to remove the mapping from
0960      * the cache.
0961      */
0962     if (mapping->cache)
0963         list_del(&mapping->entry);
0964
0965     spin_lock(&mapping->bo->lock);
0966     list_del(&mapping->list);
0967     spin_unlock(&mapping->bo->lock);
0968
0969     mapping->bo->ops->unpin(mapping);
0970 }
0971
0972 void host1x_bo_unpin(struct host1x_bo_mapping *mapping)
0973 {
0974     struct host1x_bo_cache *cache = mapping->cache;
0975
0976     if (cache)
0977         mutex_lock(&cache->lock);
0978
0979     kref_put(&mapping->ref, __host1x_bo_unpin);
0980
0981     if (cache)
0982         mutex_unlock(&cache->lock);
0983 }
0984 EXPORT_SYMBOL(host1x_bo_unpin);