kernel/drivers/gpu/host1x/bus.c

   1 /*
   2  * Copyright (C) 2012 Avionic Design GmbH
   3  * Copyright (C) 2012-2013, NVIDIA Corporation
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/host1x.h>
  19 #include <linux/of.h>
  20 #include <linux/slab.h>
  21
  22 #include "bus.h"
  23 #include "dev.h"
  24
  25 static DEFINE_MUTEX(clients_lock);
  26 static LIST_HEAD(clients);
  27
  28 static DEFINE_MUTEX(drivers_lock);
  29 static LIST_HEAD(drivers);
  30
  31 static DEFINE_MUTEX(devices_lock);
  32 static LIST_HEAD(devices);
  33
  34 struct host1x_subdev {
  35         struct host1x_client *client;
  36         struct device_node *np;
  37         struct list_head list;
  38 };
  39
  40 /**
  41  * host1x_subdev_add() - add a new subdevice with an associated device node
  42  */
  43 static int host1x_subdev_add(struct host1x_device *device,
  44                              struct device_node *np)
  45 {
  46         struct host1x_subdev *subdev;
  47
  48         subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
  49         if (!subdev)
  50                 return -ENOMEM;
  51
  52         INIT_LIST_HEAD(&subdev->list);
  53         subdev->np = of_node_get(np);
  54
  55         mutex_lock(&device->subdevs_lock);
  56         list_add_tail(&subdev->list, &device->subdevs);
  57         mutex_unlock(&device->subdevs_lock);
  58
  59         return 0;
  60 }
  61
  62 /**
  63  * host1x_subdev_del() - remove subdevice
  64  */
  65 static void host1x_subdev_del(struct host1x_subdev *subdev)
  66 {
  67         list_del(&subdev->list);
  68         of_node_put(subdev->np);
  69         kfree(subdev);
  70 }
  71
  72 /**
  73  * host1x_device_parse_dt() - scan device tree and add matching subdevices
  74  */
  75 static int host1x_device_parse_dt(struct host1x_device *device,
  76                                   struct host1x_driver *driver)
  77 {
  78         struct device_node *np;
  79         int err;
  80
  81         for_each_child_of_node(device->dev.parent->of_node, np) {
  82                 if (of_match_node(driver->subdevs, np) &&
  83                     of_device_is_available(np)) {
  84                         err = host1x_subdev_add(device, np);
  85                         if (err < 0)
  86                                 return err;
  87                 }
  88         }
  89
  90         return 0;
  91 }
  92
  93 static void host1x_subdev_register(struct host1x_device *device,
  94                                    struct host1x_subdev *subdev,
  95                                    struct host1x_client *client)
  96 {
  97         int err;
  98
  99         /*
 100          * Move the subdevice to the list of active (registered) subdevices
 101          * and associate it with a client. At the same time, associate the
 102          * client with its parent device.
 103          */
 104         mutex_lock(&device->subdevs_lock);
 105         mutex_lock(&device->clients_lock);
 106         list_move_tail(&client->list, &device->clients);
 107         list_move_tail(&subdev->list, &device->active);
 108         client->parent = &device->dev;
 109         subdev->client = client;
 110         mutex_unlock(&device->clients_lock);
 111         mutex_unlock(&device->subdevs_lock);
 112
 113         if (list_empty(&device->subdevs)) {
 114                 err = device_add(&device->dev);
 115                 if (err < 0)
 116                         dev_err(&device->dev, "failed to add: %d\n", err);
 117                 else
 118                         device->registered = true;
 119         }
 120 }
 121
 122 static void __host1x_subdev_unregister(struct host1x_device *device,
 123                                        struct host1x_subdev *subdev)
 124 {
 125         struct host1x_client *client = subdev->client;
 126
 127         /*
 128          * If all subdevices have been activated, we're about to remove the
 129          * first active subdevice, so unload the driver first.
 130          */
 131         if (list_empty(&device->subdevs)) {
 132                 if (device->registered) {
 133                         device->registered = false;
 134                         device_del(&device->dev);
 135                 }
 136         }
 137
 138         /*
 139          * Move the subdevice back to the list of idle subdevices and remove
 140          * it from list of clients.
 141          */
 142         mutex_lock(&device->clients_lock);
 143         subdev->client = NULL;
 144         client->parent = NULL;
 145         list_move_tail(&subdev->list, &device->subdevs);
 146         /*
 147          * XXX: Perhaps don't do this here, but rather explicitly remove it
 148          * when the device is about to be deleted.
 149          *
 150          * This is somewhat complicated by the fact that this function is
 151          * used to remove the subdevice when a client is unregistered but
 152          * also when the composite device is about to be removed.
 153          */
 154         list_del_init(&client->list);
 155         mutex_unlock(&device->clients_lock);
 156 }
 157
 158 static void host1x_subdev_unregister(struct host1x_device *device,
 159                                      struct host1x_subdev *subdev)
 160 {
 161         mutex_lock(&device->subdevs_lock);
 162         __host1x_subdev_unregister(device, subdev);
 163         mutex_unlock(&device->subdevs_lock);
 164 }
 165
 166 int host1x_device_init(struct host1x_device *device)
 167 {
 168         struct host1x_client *client;
 169         int err;
 170
 171         mutex_lock(&device->clients_lock);
 172
 173         list_for_each_entry(client, &device->clients, list) {
 174                 if (client->ops && client->ops->init) {
 175                         err = client->ops->init(client);
 176                         if (err < 0) {
 177                                 dev_err(&device->dev,
 178                                         "failed to initialize %s: %d\n",
 179                                         dev_name(client->dev), err);
 180                                 mutex_unlock(&device->clients_lock);
 181                                 return err;
 182                         }
 183                 }
 184         }
 185
 186         mutex_unlock(&device->clients_lock);
 187
 188         return 0;
 189 }
 190 EXPORT_SYMBOL(host1x_device_init);
 191
 192 int host1x_device_exit(struct host1x_device *device)
 193 {
 194         struct host1x_client *client;
 195         int err;
 196
 197         mutex_lock(&device->clients_lock);
 198
 199         list_for_each_entry_reverse(client, &device->clients, list) {
 200                 if (client->ops && client->ops->exit) {
 201                         err = client->ops->exit(client);
 202                         if (err < 0) {
 203                                 dev_err(&device->dev,
 204                                         "failed to cleanup %s: %d\n",
 205                                         dev_name(client->dev), err);
 206                                 mutex_unlock(&device->clients_lock);
 207                                 return err;
 208                         }
 209                 }
 210         }
 211
 212         mutex_unlock(&device->clients_lock);
 213
 214         return 0;
 215 }
 216 EXPORT_SYMBOL(host1x_device_exit);
 217
 218 static int host1x_add_client(struct host1x *host1x,
 219                              struct host1x_client *client)
 220 {
 221         struct host1x_device *device;
 222         struct host1x_subdev *subdev;
 223
 224         mutex_lock(&host1x->devices_lock);
 225
 226         list_for_each_entry(device, &host1x->devices, list) {
 227                 list_for_each_entry(subdev, &device->subdevs, list) {
 228                         if (subdev->np == client->dev->of_node) {
 229                                 host1x_subdev_register(device, subdev, client);
 230                                 mutex_unlock(&host1x->devices_lock);
 231                                 return 0;
 232                         }
 233                 }
 234         }
 235
 236         mutex_unlock(&host1x->devices_lock);
 237         return -ENODEV;
 238 }
 239
 240 static int host1x_del_client(struct host1x *host1x,
 241                              struct host1x_client *client)
 242 {
 243         struct host1x_device *device, *dt;
 244         struct host1x_subdev *subdev;
 245
 246         mutex_lock(&host1x->devices_lock);
 247
 248         list_for_each_entry_safe(device, dt, &host1x->devices, list) {
 249                 list_for_each_entry(subdev, &device->active, list) {
 250                         if (subdev->client == client) {
 251                                 host1x_subdev_unregister(device, subdev);
 252                                 mutex_unlock(&host1x->devices_lock);
 253                                 return 0;
 254                         }
 255                 }
 256         }
 257
 258         mutex_unlock(&host1x->devices_lock);
 259         return -ENODEV;
 260 }
 261
 262 static int host1x_device_match(struct device *dev, struct device_driver *drv)
 263 {
 264         return strcmp(dev_name(dev), drv->name) == 0;
 265 }
 266
 267 static int host1x_device_probe(struct device *dev)
 268 {
 269         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 270         struct host1x_device *device = to_host1x_device(dev);
 271
 272         if (driver->probe)
 273                 return driver->probe(device);
 274
 275         return 0;
 276 }
 277
 278 static int host1x_device_remove(struct device *dev)
 279 {
 280         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 281         struct host1x_device *device = to_host1x_device(dev);
 282
 283         if (driver->remove)
 284                 return driver->remove(device);
 285
 286         return 0;
 287 }
 288
 289 static void host1x_device_shutdown(struct device *dev)
 290 {
 291         struct host1x_driver *driver = to_host1x_driver(dev->driver);
 292         struct host1x_device *device = to_host1x_device(dev);
 293
 294         if (driver->shutdown)
 295                 driver->shutdown(device);
 296 }
 297
 298 static const struct dev_pm_ops host1x_device_pm_ops = {
 299         .suspend = pm_generic_suspend,
 300         .resume = pm_generic_resume,
 301         .freeze = pm_generic_freeze,
 302         .thaw = pm_generic_thaw,
 303         .poweroff = pm_generic_poweroff,
 304         .restore = pm_generic_restore,
 305 };
 306
 307 struct bus_type host1x_bus_type = {
 308         .name = "host1x",
 309         .match = host1x_device_match,
 310         .probe = host1x_device_probe,
 311         .remove = host1x_device_remove,
 312         .shutdown = host1x_device_shutdown,
 313         .pm = &host1x_device_pm_ops,
 314 };
 315
 316 static void __host1x_device_del(struct host1x_device *device)
 317 {
 318         struct host1x_subdev *subdev, *sd;
 319         struct host1x_client *client, *cl;
 320
 321         mutex_lock(&device->subdevs_lock);
 322
 323         /* unregister subdevices */
 324         list_for_each_entry_safe(subdev, sd, &device->active, list) {
 325                 /*
 326                  * host1x_subdev_unregister() will remove the client from
 327                  * any lists, so we'll need to manually add it back to the
 328                  * list of idle clients.
 329                  *
 330                  * XXX: Alternatively, perhaps don't remove the client from
 331                  * any lists in host1x_subdev_unregister() and instead do
 332                  * that explicitly from host1x_unregister_client()?
 333                  */
 334                 client = subdev->client;
 335
 336                 __host1x_subdev_unregister(device, subdev);
 337
 338                 /* add the client to the list of idle clients */
 339                 mutex_lock(&clients_lock);
 340                 list_add_tail(&client->list, &clients);
 341                 mutex_unlock(&clients_lock);
 342         }
 343
 344         /* remove subdevices */
 345         list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
 346                 host1x_subdev_del(subdev);
 347
 348         mutex_unlock(&device->subdevs_lock);
 349
 350         /* move clients to idle list */
 351         mutex_lock(&clients_lock);
 352         mutex_lock(&device->clients_lock);
 353
 354         list_for_each_entry_safe(client, cl, &device->clients, list)
 355                 list_move_tail(&client->list, &clients);
 356
 357         mutex_unlock(&device->clients_lock);
 358         mutex_unlock(&clients_lock);
 359
 360         /* finally remove the device */
 361         list_del_init(&device->list);
 362 }
 363
 364 static void host1x_device_release(struct device *dev)
 365 {
 366         struct host1x_device *device = to_host1x_device(dev);
 367
 368         __host1x_device_del(device);
 369         kfree(device);
 370 }
 371
 372 static int host1x_device_add(struct host1x *host1x,
 373                              struct host1x_driver *driver)
 374 {
 375         struct host1x_client *client, *tmp;
 376         struct host1x_subdev *subdev;
 377         struct host1x_device *device;
 378         int err;
 379
 380         device = kzalloc(sizeof(*device), GFP_KERNEL);
 381         if (!device)
 382                 return -ENOMEM;
 383
 384         device_initialize(&device->dev);
 385
 386         mutex_init(&device->subdevs_lock);
 387         INIT_LIST_HEAD(&device->subdevs);
 388         INIT_LIST_HEAD(&device->active);
 389         mutex_init(&device->clients_lock);
 390         INIT_LIST_HEAD(&device->clients);
 391         INIT_LIST_HEAD(&device->list);
 392         device->driver = driver;
 393
 394         device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
 395         device->dev.dma_mask = &device->dev.coherent_dma_mask;
 396         dev_set_name(&device->dev, "%s", driver->driver.name);
 397         device->dev.release = host1x_device_release;
 398         device->dev.bus = &host1x_bus_type;
 399         device->dev.parent = host1x->dev;
 400
 401         err = host1x_device_parse_dt(device, driver);
 402         if (err < 0) {
 403                 kfree(device);
 404                 return err;
 405         }
 406
 407         list_add_tail(&device->list, &host1x->devices);
 408
 409         mutex_lock(&clients_lock);
 410
 411         list_for_each_entry_safe(client, tmp, &clients, list) {
 412                 list_for_each_entry(subdev, &device->subdevs, list) {
 413                         if (subdev->np == client->dev->of_node) {
 414                                 host1x_subdev_register(device, subdev, client);
 415                                 break;
 416                         }
 417                 }
 418         }
 419
 420         mutex_unlock(&clients_lock);
 421
 422         return 0;
 423 }
 424
 425 /*
 426  * Removes a device by first unregistering any subdevices and then removing
 427  * itself from the list of devices.
 428  *
 429  * This function must be called with the host1x->devices_lock held.
 430  */
 431 static void host1x_device_del(struct host1x *host1x,
 432                               struct host1x_device *device)
 433 {
 434         if (device->registered) {
 435                 device->registered = false;
 436                 device_del(&device->dev);
 437         }
 438
 439         put_device(&device->dev);
 440 }
 441
 442 static void host1x_attach_driver(struct host1x *host1x,
 443                                  struct host1x_driver *driver)
 444 {
 445         struct host1x_device *device;
 446         int err;
 447
 448         mutex_lock(&host1x->devices_lock);
 449
 450         list_for_each_entry(device, &host1x->devices, list) {
 451                 if (device->driver == driver) {
 452                         mutex_unlock(&host1x->devices_lock);
 453                         return;
 454                 }
 455         }
 456
 457         err = host1x_device_add(host1x, driver);
 458         if (err < 0)
 459                 dev_err(host1x->dev, "failed to allocate device: %d\n", err);
 460
 461         mutex_unlock(&host1x->devices_lock);
 462 }
 463
 464 static void host1x_detach_driver(struct host1x *host1x,
 465                                  struct host1x_driver *driver)
 466 {
 467         struct host1x_device *device, *tmp;
 468
 469         mutex_lock(&host1x->devices_lock);
 470
 471         list_for_each_entry_safe(device, tmp, &host1x->devices, list)
 472                 if (device->driver == driver)
 473                         host1x_device_del(host1x, device);
 474
 475         mutex_unlock(&host1x->devices_lock);
 476 }
 477
 478 int host1x_register(struct host1x *host1x)
 479 {
 480         struct host1x_driver *driver;
 481
 482         mutex_lock(&devices_lock);
 483         list_add_tail(&host1x->list, &devices);
 484         mutex_unlock(&devices_lock);
 485
 486         mutex_lock(&drivers_lock);
 487
 488         list_for_each_entry(driver, &drivers, list)
 489                 host1x_attach_driver(host1x, driver);
 490
 491         mutex_unlock(&drivers_lock);
 492
 493         return 0;
 494 }
 495
 496 int host1x_unregister(struct host1x *host1x)
 497 {
 498         struct host1x_driver *driver;
 499
 500         mutex_lock(&drivers_lock);
 501
 502         list_for_each_entry(driver, &drivers, list)
 503                 host1x_detach_driver(host1x, driver);
 504
 505         mutex_unlock(&drivers_lock);
 506
 507         mutex_lock(&devices_lock);
 508         list_del_init(&host1x->list);
 509         mutex_unlock(&devices_lock);
 510
 511         return 0;
 512 }
 513
 514 int host1x_driver_register_full(struct host1x_driver *driver,
 515                                 struct module *owner)
 516 {
 517         struct host1x *host1x;
 518
 519         INIT_LIST_HEAD(&driver->list);
 520
 521         mutex_lock(&drivers_lock);
 522         list_add_tail(&driver->list, &drivers);
 523         mutex_unlock(&drivers_lock);
 524
 525         mutex_lock(&devices_lock);
 526
 527         list_for_each_entry(host1x, &devices, list)
 528                 host1x_attach_driver(host1x, driver);
 529
 530         mutex_unlock(&devices_lock);
 531
 532         driver->driver.bus = &host1x_bus_type;
 533         driver->driver.owner = owner;
 534
 535         return driver_register(&driver->driver);
 536 }
 537 EXPORT_SYMBOL(host1x_driver_register_full);
 538
 539 void host1x_driver_unregister(struct host1x_driver *driver)
 540 {
 541         mutex_lock(&drivers_lock);
 542         list_del_init(&driver->list);
 543         mutex_unlock(&drivers_lock);
 544 }
 545 EXPORT_SYMBOL(host1x_driver_unregister);
 546
 547 int host1x_client_register(struct host1x_client *client)
 548 {
 549         struct host1x *host1x;
 550         int err;
 551
 552         mutex_lock(&devices_lock);
 553
 554         list_for_each_entry(host1x, &devices, list) {
 555                 err = host1x_add_client(host1x, client);
 556                 if (!err) {
 557                         mutex_unlock(&devices_lock);
 558                         return 0;
 559                 }
 560         }
 561
 562         mutex_unlock(&devices_lock);
 563
 564         mutex_lock(&clients_lock);
 565         list_add_tail(&client->list, &clients);
 566         mutex_unlock(&clients_lock);
 567
 568         return 0;
 569 }
 570 EXPORT_SYMBOL(host1x_client_register);
 571
 572 int host1x_client_unregister(struct host1x_client *client)
 573 {
 574         struct host1x_client *c;
 575         struct host1x *host1x;
 576         int err;
 577
 578         mutex_lock(&devices_lock);
 579
 580         list_for_each_entry(host1x, &devices, list) {
 581                 err = host1x_del_client(host1x, client);
 582                 if (!err) {
 583                         mutex_unlock(&devices_lock);
 584                         return 0;
 585                 }
 586         }
 587
 588         mutex_unlock(&devices_lock);
 589         mutex_lock(&clients_lock);
 590
 591         list_for_each_entry(c, &clients, list) {
 592                 if (c == client) {
 593                         list_del_init(&c->list);
 594                         break;
 595                 }
 596         }
 597
 598         mutex_unlock(&clients_lock);
 599
 600         return 0;
 601 }
 602 EXPORT_SYMBOL(host1x_client_unregister);