drivers/gpu/host1x/bus.c

   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
  18 static DEFINE_MUTEX(clients_lock);
  19 static LIST_HEAD(clients);
  20
  21 static DEFINE_MUTEX(drivers_lock);
  22 static LIST_HEAD(drivers);
  23
  24 static DEFINE_MUTEX(devices_lock);
  25 static LIST_HEAD(devices);
  26
  27 struct 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  */
  39 static 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  */
  78 static 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  */
  90 static 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
 110 static 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
 139 static 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
 175 static 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  */
 193 int 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
 227 teardown:
 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
 235 teardown_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 }
 243 EXPORT_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  */
 254 int 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 }
 290 EXPORT_SYMBOL(host1x_device_exit);
 291
 292 static 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
 314 static 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
 336 static int host1x_device_match(struct device *dev, const 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  */
 346 static 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
 354 static 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
 363 const 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
 370 static 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
 418 static 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
 426 static 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  */
 488 static 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
 499 static 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
 521 static 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
 535 static 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 }
 563 DEFINE_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  */
 573 int 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  */
 601 int 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
 619 static 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
 630 static 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
 641 static 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  */
 660 int 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 }
 686 EXPORT_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  */
 695 void 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 }
 712 EXPORT_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  */
 719 void __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 }
 726 EXPORT_SYMBOL(__host1x_client_init);
 727
 728 /**
 729  * host1x_client_exit() - uninitialize a host1x client
 730  * @client: host1x client
 731  */
 732 void host1x_client_exit(struct host1x_client *client)
 733 {
 734         mutex_destroy(&client->lock);
 735 }
 736 EXPORT_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  */
 749 int __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 }
 772 EXPORT_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  */
 781 void 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 }
 811 EXPORT_SYMBOL(host1x_client_unregister);
 812
 813 int 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
 838 resume:
 839         if (client->usecount == 0)
 840                 if (client->ops && client->ops->resume)
 841                         client->ops->resume(client);
 842
 843         client->usecount++;
 844 unlock:
 845         mutex_unlock(&client->lock);
 846         return err;
 847 }
 848 EXPORT_SYMBOL(host1x_client_suspend);
 849
 850 int 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
 875 suspend:
 876         if (client->parent)
 877                 host1x_client_suspend(client->parent);
 878 unlock:
 879         mutex_unlock(&client->lock);
 880         return err;
 881 }
 882 EXPORT_SYMBOL(host1x_client_resume);
 883
 884 struct 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
 919 unlock:
 920         if (cache)
 921                 mutex_unlock(&cache->lock);
 922
 923         return mapping;
 924 }
 925 EXPORT_SYMBOL(host1x_bo_pin);
 926
 927 static 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
 945 void 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 }
 957 EXPORT_SYMBOL(host1x_bo_unpin);