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, 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 int host1x_dma_configure(struct device *dev)
 355 {
 356         return of_dma_configure(dev, dev->of_node, true);
 357 }
 358
 359 static const struct dev_pm_ops host1x_device_pm_ops = {
 360         .suspend = pm_generic_suspend,
 361         .resume = pm_generic_resume,
 362         .freeze = pm_generic_freeze,
 363         .thaw = pm_generic_thaw,
 364         .poweroff = pm_generic_poweroff,
 365         .restore = pm_generic_restore,
 366 };
 367
 368 struct bus_type host1x_bus_type = {
 369         .name = "host1x",
 370         .match = host1x_device_match,
 371         .uevent = host1x_device_uevent,
 372         .dma_configure = host1x_dma_configure,
 373         .pm = &host1x_device_pm_ops,
 374 };
 375
 376 static void __host1x_device_del(struct host1x_device *device)
 377 {
 378         struct host1x_subdev *subdev, *sd;
 379         struct host1x_client *client, *cl;
 380
 381         mutex_lock(&device->subdevs_lock);
 382
 383         /* unregister subdevices */
 384         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 385                 /*
 386                  * host1x_subdev_unregister() will remove the client from
 387                  * any lists, so we'll need to manually add it back to the
 388                  * list of idle clients.
 389                  *
 390                  * XXX: Alternatively, perhaps don't remove the client from
 391                  * any lists in host1x_subdev_unregister() and instead do
 392                  * that explicitly from host1x_unregister_client()?
 393                  */
 394                 client = subdev->client;
 395
 396                 __host1x_subdev_unregister(device, subdev);
 397
 398                 /* add the client to the list of idle clients */
 399                 mutex_lock(&clients_lock);
 400                 list_add_tail(&client->list, &clients);
 401                 mutex_unlock(&clients_lock);
 402         }
 403
 404         /* remove subdevices */
 405         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 406                 host1x_subdev_del(subdev);
 407
 408         mutex_unlock(&device->subdevs_lock);
 409
 410         /* move clients to idle list */
 411         mutex_lock(&clients_lock);
 412         mutex_lock(&device->clients_lock);
 413
 414         list_for_each_entry_safe(client, cl, &device->clients, list)
 415                 list_move_tail(&client->list, &clients);
 416
 417         mutex_unlock(&device->clients_lock);
 418         mutex_unlock(&clients_lock);
 419
 420         /* finally remove the device */
 421         list_del_init(&device->list);
 422 }
 423
 424 static void host1x_device_release(struct device *dev)
 425 {
 426         struct host1x_device *device = to_host1x_device(dev);
 427
 428         __host1x_device_del(device);
 429         kfree(device);
 430 }
 431
 432 static int host1x_device_add(struct host1x *host1x,
 433                              struct host1x_driver *driver)
 434 {
 435         struct host1x_client *client, *tmp;
 436         struct host1x_subdev *subdev;
 437         struct host1x_device *device;
 438         int err;
 439
 440         device = kzalloc(sizeof(*device), GFP_KERNEL);
 441         if (!device)
 442                 return -ENOMEM;
 443
 444         device_initialize(&device->dev);
 445
 446         mutex_init(&device->subdevs_lock);
 447         INIT_LIST_HEAD(&device->subdevs);
 448         INIT_LIST_HEAD(&device->active);
 449         mutex_init(&device->clients_lock);
 450         INIT_LIST_HEAD(&device->clients);
 451         INIT_LIST_HEAD(&device->list);
 452         device->driver = driver;
 453
 454         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 455         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 456         dev_set_name(&device->dev, "%s", driver->driver.name);
 457         device->dev.release = host1x_device_release;
 458         device->dev.bus = &host1x_bus_type;
 459         device->dev.parent = host1x->dev;
 460
 461         of_dma_configure(&device->dev, host1x->dev->of_node, true);
 462
 463         device->dev.dma_parms = &device->dma_parms;
 464         dma_set_max_seg_size(&device->dev, UINT_MAX);
 465
 466         err = host1x_device_parse_dt(device, driver);
 467         if (err < 0) {
 468                 kfree(device);
 469                 return err;
 470         }
 471
 472         list_add_tail(&device->list, &host1x->devices);
 473
 474         mutex_lock(&clients_lock);
 475
 476         list_for_each_entry_safe(client, tmp, &clients, list) {
 477                 list_for_each_entry(subdev, &device->subdevs, list) {
 478                         if (subdev->np == client->dev->of_node) {
 479                                 host1x_subdev_register(device, subdev, client);
 480                                 break;
 481                         }
 482                 }
 483         }
 484
 485         mutex_unlock(&clients_lock);
 486
 487         return 0;
 488 }
 489
 490 /*
 491  * Removes a device by first unregistering any subdevices and then removing
 492  * itself from the list of devices.
 493  *
 494  * This function must be called with the host1x->devices_lock held.
 495  */
 496 static void host1x_device_del(struct host1x *host1x,
 497                               struct host1x_device *device)
 498 {
 499         if (device->registered) {
 500                 device->registered = false;
 501                 device_del(&device->dev);
 502         }
 503
 504         put_device(&device->dev);
 505 }
 506
 507 static void host1x_attach_driver(struct host1x *host1x,
 508                                  struct host1x_driver *driver)
 509 {
 510         struct host1x_device *device;
 511         int err;
 512
 513         mutex_lock(&host1x->devices_lock);
 514
 515         list_for_each_entry(device, &host1x->devices, list) {
 516                 if (device->driver == driver) {
 517                         mutex_unlock(&host1x->devices_lock);
 518                         return;
 519                 }
 520         }
 521
 522         err = host1x_device_add(host1x, driver);
 523         if (err < 0)
 524                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 525
 526         mutex_unlock(&host1x->devices_lock);
 527 }
 528
 529 static void host1x_detach_driver(struct host1x *host1x,
 530                                  struct host1x_driver *driver)
 531 {
 532         struct host1x_device *device, *tmp;
 533
 534         mutex_lock(&host1x->devices_lock);
 535
 536         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 537                 if (device->driver == driver)
 538                         host1x_device_del(host1x, device);
 539
 540         mutex_unlock(&host1x->devices_lock);
 541 }
 542
 543 static int host1x_devices_show(struct seq_file *s, void *data)
 544 {
 545         struct host1x *host1x = s->private;
 546         struct host1x_device *device;
 547
 548         mutex_lock(&host1x->devices_lock);
 549
 550         list_for_each_entry(device, &host1x->devices, list) {
 551                 struct host1x_subdev *subdev;
 552
 553                 seq_printf(s, "%s\n", dev_name(&device->dev));
 554
 555                 mutex_lock(&device->subdevs_lock);
 556
 557                 list_for_each_entry(subdev, &device->active, list)
 558                         seq_printf(s, "  %pOFf: %s\n", subdev->np,
 559                                    dev_name(subdev->client->dev));
 560
 561                 list_for_each_entry(subdev, &device->subdevs, list)
 562                         seq_printf(s, "  %pOFf:\n", subdev->np);
 563
 564                 mutex_unlock(&device->subdevs_lock);
 565         }
 566
 567         mutex_unlock(&host1x->devices_lock);
 568
 569         return 0;
 570 }
 571 DEFINE_SHOW_ATTRIBUTE(host1x_devices);
 572
 573 /**
 574  * host1x_register() - register a host1x controller
 575  * @host1x: host1x controller
 576  *
 577  * The host1x controller driver uses this to register a host1x controller with
 578  * the infrastructure. Note that all Tegra SoC generations have only ever come
 579  * with a single host1x instance, so this function is somewhat academic.
 580  */
 581 int host1x_register(struct host1x *host1x)
 582 {
 583         struct host1x_driver *driver;
 584
 585         mutex_lock(&devices_lock);
 586         list_add_tail(&host1x->list, &devices);
 587         mutex_unlock(&devices_lock);
 588
 589         mutex_lock(&drivers_lock);
 590
 591         list_for_each_entry(driver, &drivers, list)
 592                 host1x_attach_driver(host1x, driver);
 593
 594         mutex_unlock(&drivers_lock);
 595
 596         debugfs_create_file("devices", S_IRUGO, host1x->debugfs, host1x,
 597                             &host1x_devices_fops);
 598
 599         return 0;
 600 }
 601
 602 /**
 603  * host1x_unregister() - unregister a host1x controller
 604  * @host1x: host1x controller
 605  *
 606  * The host1x controller driver uses this to remove a host1x controller from
 607  * the infrastructure.
 608  */
 609 int host1x_unregister(struct host1x *host1x)
 610 {
 611         struct host1x_driver *driver;
 612
 613         mutex_lock(&drivers_lock);
 614
 615         list_for_each_entry(driver, &drivers, list)
 616                 host1x_detach_driver(host1x, driver);
 617
 618         mutex_unlock(&drivers_lock);
 619
 620         mutex_lock(&devices_lock);
 621         list_del_init(&host1x->list);
 622         mutex_unlock(&devices_lock);
 623
 624         return 0;
 625 }
 626
 627 static int host1x_device_probe(struct device *dev)
 628 {
 629         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 630         struct host1x_device *device = to_host1x_device(dev);
 631
 632         if (driver->probe)
 633                 return driver->probe(device);
 634
 635         return 0;
 636 }
 637
 638 static int host1x_device_remove(struct device *dev)
 639 {
 640         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 641         struct host1x_device *device = to_host1x_device(dev);
 642
 643         if (driver->remove)
 644                 return driver->remove(device);
 645
 646         return 0;
 647 }
 648
 649 static void host1x_device_shutdown(struct device *dev)
 650 {
 651         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 652         struct host1x_device *device = to_host1x_device(dev);
 653
 654         if (driver->shutdown)
 655                 driver->shutdown(device);
 656 }
 657
 658 /**
 659  * host1x_driver_register_full() - register a host1x driver
 660  * @driver: host1x driver
 661  * @owner: owner module
 662  *
 663  * Drivers for host1x logical devices call this function to register a driver
 664  * with the infrastructure. Note that since these drive logical devices, the
 665  * registration of the driver actually triggers tho logical device creation.
 666  * A logical device will be created for each host1x instance.
 667  */
 668 int host1x_driver_register_full(struct host1x_driver *driver,
 669                                 struct module *owner)
 670 {
 671         struct host1x *host1x;
 672
 673         INIT_LIST_HEAD(&driver->list);
 674
 675         mutex_lock(&drivers_lock);
 676         list_add_tail(&driver->list, &drivers);
 677         mutex_unlock(&drivers_lock);
 678
 679         mutex_lock(&devices_lock);
 680
 681         list_for_each_entry(host1x, &devices, list)
 682                 host1x_attach_driver(host1x, driver);
 683
 684         mutex_unlock(&devices_lock);
 685
 686         driver->driver.bus = &host1x_bus_type;
 687         driver->driver.owner = owner;
 688         driver->driver.probe = host1x_device_probe;
 689         driver->driver.remove = host1x_device_remove;
 690         driver->driver.shutdown = host1x_device_shutdown;
 691
 692         return driver_register(&driver->driver);
 693 }
 694 EXPORT_SYMBOL(host1x_driver_register_full);
 695
 696 /**
 697  * host1x_driver_unregister() - unregister a host1x driver
 698  * @driver: host1x driver
 699  *
 700  * Unbinds the driver from each of the host1x logical devices that it is
 701  * bound to, effectively removing the subsystem devices that they represent.
 702  */
 703 void host1x_driver_unregister(struct host1x_driver *driver)
 704 {
 705         struct host1x *host1x;
 706
 707         driver_unregister(&driver->driver);
 708
 709         mutex_lock(&devices_lock);
 710
 711         list_for_each_entry(host1x, &devices, list)
 712                 host1x_detach_driver(host1x, driver);
 713
 714         mutex_unlock(&devices_lock);
 715
 716         mutex_lock(&drivers_lock);
 717         list_del_init(&driver->list);
 718         mutex_unlock(&drivers_lock);
 719 }
 720 EXPORT_SYMBOL(host1x_driver_unregister);
 721
 722 /**
 723  * __host1x_client_init() - initialize a host1x client
 724  * @client: host1x client
 725  * @key: lock class key for the client-specific mutex
 726  */
 727 void __host1x_client_init(struct host1x_client *client, struct lock_class_key *key)
 728 {
 729         host1x_bo_cache_init(&client->cache);
 730         INIT_LIST_HEAD(&client->list);
 731         __mutex_init(&client->lock, "host1x client lock", key);
 732         client->usecount = 0;
 733 }
 734 EXPORT_SYMBOL(__host1x_client_init);
 735
 736 /**
 737  * host1x_client_exit() - uninitialize a host1x client
 738  * @client: host1x client
 739  */
 740 void host1x_client_exit(struct host1x_client *client)
 741 {
 742         mutex_destroy(&client->lock);
 743 }
 744 EXPORT_SYMBOL(host1x_client_exit);
 745
 746 /**
 747  * __host1x_client_register() - register a host1x client
 748  * @client: host1x client
 749  *
 750  * Registers a host1x client with each host1x controller instance. Note that
 751  * each client will only match their parent host1x controller and will only be
 752  * associated with that instance. Once all clients have been registered with
 753  * their parent host1x controller, the infrastructure will set up the logical
 754  * device and call host1x_device_init(), which will in turn call each client's
 755  * &host1x_client_ops.init implementation.
 756  */
 757 int __host1x_client_register(struct host1x_client *client)
 758 {
 759         struct host1x *host1x;
 760         int err;
 761
 762         mutex_lock(&devices_lock);
 763
 764         list_for_each_entry(host1x, &devices, list) {
 765                 err = host1x_add_client(host1x, client);
 766                 if (!err) {
 767                         mutex_unlock(&devices_lock);
 768                         return 0;
 769                 }
 770         }
 771
 772         mutex_unlock(&devices_lock);
 773
 774         mutex_lock(&clients_lock);
 775         list_add_tail(&client->list, &clients);
 776         mutex_unlock(&clients_lock);
 777
 778         return 0;
 779 }
 780 EXPORT_SYMBOL(__host1x_client_register);
 781
 782 /**
 783  * host1x_client_unregister() - unregister a host1x client
 784  * @client: host1x client
 785  *
 786  * Removes a host1x client from its host1x controller instance. If a logical
 787  * device has already been initialized, it will be torn down.
 788  */
 789 void host1x_client_unregister(struct host1x_client *client)
 790 {
 791         struct host1x_client *c;
 792         struct host1x *host1x;
 793         int err;
 794
 795         mutex_lock(&devices_lock);
 796
 797         list_for_each_entry(host1x, &devices, list) {
 798                 err = host1x_del_client(host1x, client);
 799                 if (!err) {
 800                         mutex_unlock(&devices_lock);
 801                         return;
 802                 }
 803         }
 804
 805         mutex_unlock(&devices_lock);
 806         mutex_lock(&clients_lock);
 807
 808         list_for_each_entry(c, &clients, list) {
 809                 if (c == client) {
 810                         list_del_init(&c->list);
 811                         break;
 812                 }
 813         }
 814
 815         mutex_unlock(&clients_lock);
 816
 817         host1x_bo_cache_destroy(&client->cache);
 818 }
 819 EXPORT_SYMBOL(host1x_client_unregister);
 820
 821 int host1x_client_suspend(struct host1x_client *client)
 822 {
 823         int err = 0;
 824
 825         mutex_lock(&client->lock);
 826
 827         if (client->usecount == 1) {
 828                 if (client->ops && client->ops->suspend) {
 829                         err = client->ops->suspend(client);
 830                         if (err < 0)
 831                                 goto unlock;
 832                 }
 833         }
 834
 835         client->usecount--;
 836         dev_dbg(client->dev, "use count: %u\n", client->usecount);
 837
 838         if (client->parent) {
 839                 err = host1x_client_suspend(client->parent);
 840                 if (err < 0)
 841                         goto resume;
 842         }
 843
 844         goto unlock;
 845
 846 resume:
 847         if (client->usecount == 0)
 848                 if (client->ops && client->ops->resume)
 849                         client->ops->resume(client);
 850
 851         client->usecount++;
 852 unlock:
 853         mutex_unlock(&client->lock);
 854         return err;
 855 }
 856 EXPORT_SYMBOL(host1x_client_suspend);
 857
 858 int host1x_client_resume(struct host1x_client *client)
 859 {
 860         int err = 0;
 861
 862         mutex_lock(&client->lock);
 863
 864         if (client->parent) {
 865                 err = host1x_client_resume(client->parent);
 866                 if (err < 0)
 867                         goto unlock;
 868         }
 869
 870         if (client->usecount == 0) {
 871                 if (client->ops && client->ops->resume) {
 872                         err = client->ops->resume(client);
 873                         if (err < 0)
 874                                 goto suspend;
 875                 }
 876         }
 877
 878         client->usecount++;
 879         dev_dbg(client->dev, "use count: %u\n", client->usecount);
 880
 881         goto unlock;
 882
 883 suspend:
 884         if (client->parent)
 885                 host1x_client_suspend(client->parent);
 886 unlock:
 887         mutex_unlock(&client->lock);
 888         return err;
 889 }
 890 EXPORT_SYMBOL(host1x_client_resume);
 891
 892 struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
 893                                         enum dma_data_direction dir,
 894                                         struct host1x_bo_cache *cache)
 895 {
 896         struct host1x_bo_mapping *mapping;
 897
 898         if (cache) {
 899                 mutex_lock(&cache->lock);
 900
 901                 list_for_each_entry(mapping, &cache->mappings, entry) {
 902                         if (mapping->bo == bo && mapping->direction == dir) {
 903                                 kref_get(&mapping->ref);
 904                                 goto unlock;
 905                         }
 906                 }
 907         }
 908
 909         mapping = bo->ops->pin(dev, bo, dir);
 910         if (IS_ERR(mapping))
 911                 goto unlock;
 912
 913         spin_lock(&mapping->bo->lock);
 914         list_add_tail(&mapping->list, &bo->mappings);
 915         spin_unlock(&mapping->bo->lock);
 916
 917         if (cache) {
 918                 INIT_LIST_HEAD(&mapping->entry);
 919                 mapping->cache = cache;
 920
 921                 list_add_tail(&mapping->entry, &cache->mappings);
 922
 923                 /* bump reference count to track the copy in the cache */
 924                 kref_get(&mapping->ref);
 925         }
 926
 927 unlock:
 928         if (cache)
 929                 mutex_unlock(&cache->lock);
 930
 931         return mapping;
 932 }
 933 EXPORT_SYMBOL(host1x_bo_pin);
 934
 935 static void __host1x_bo_unpin(struct kref *ref)
 936 {
 937         struct host1x_bo_mapping *mapping = to_host1x_bo_mapping(ref);
 938
 939         /*
 940          * When the last reference of the mapping goes away, make sure to remove the mapping from
 941          * the cache.
 942          */
 943         if (mapping->cache)
 944                 list_del(&mapping->entry);
 945
 946         spin_lock(&mapping->bo->lock);
 947         list_del(&mapping->list);
 948         spin_unlock(&mapping->bo->lock);
 949
 950         mapping->bo->ops->unpin(mapping);
 951 }
 952
 953 void host1x_bo_unpin(struct host1x_bo_mapping *mapping)
 954 {
 955         struct host1x_bo_cache *cache = mapping->cache;
 956
 957         if (cache)
 958                 mutex_lock(&cache->lock);
 959
 960         kref_put(&mapping->ref, __host1x_bo_unpin);
 961
 962         if (cache)
 963                 mutex_unlock(&cache->lock);
 964 }
 965 EXPORT_SYMBOL(host1x_bo_unpin);