drivers/misc/mei/bus.c

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This source file includes following definitions.
__mei_cl_send
__mei_cl_recv
mei_cldev_send
mei_cldev_recv_nonblock
mei_cldev_recv
mei_cl_bus_rx_work
mei_cl_bus_notif_work
mei_cl_bus_notify_event
mei_cl_bus_rx_event
mei_cldev_register_rx_cb
mei_cldev_register_notif_cb
mei_cldev_get_drvdata
mei_cldev_set_drvdata
mei_cldev_uuid
mei_cldev_ver
mei_cldev_enabled
mei_cl_bus_module_get
mei_cl_bus_module_put
mei_cldev_enable
mei_cldev_unregister_callbacks
mei_cldev_disable
mei_cl_device_find
mei_cl_device_match
mei_cl_device_probe
mei_cl_device_remove
name_show
uuid_show
version_show
modalias_show
mei_cl_device_uevent
mei_dev_bus_get
mei_dev_bus_put
mei_cl_bus_dev_release
mei_cl_bus_set_name
mei_cl_bus_dev_alloc
mei_cl_bus_dev_setup
mei_cl_bus_dev_add
mei_cl_bus_dev_stop
mei_cl_bus_dev_destroy
mei_cl_bus_remove_device
mei_cl_bus_remove_devices
mei_cl_bus_dev_init
mei_cl_bus_rescan
mei_cl_bus_rescan_work
__mei_cldev_driver_register
mei_cldev_driver_unregister
mei_cl_bus_init
mei_cl_bus_exit
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
   4  * Intel Management Engine Interface (Intel MEI) Linux driver
   5  */
   6 
   7 #include <linux/module.h>
   8 #include <linux/device.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched/signal.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <linux/slab.h>
  14 #include <linux/mutex.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/mei_cl_bus.h>
  17 
  18 #include "mei_dev.h"
  19 #include "client.h"
  20 
  21 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
  22 
  23 /**
  24  * __mei_cl_send - internal client send (write)
  25  *
  26  * @cl: host client
  27  * @buf: buffer to send
  28  * @length: buffer length
  29  * @mode: sending mode
  30  *
  31  * Return: written size bytes or < 0 on error
  32  */
  33 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
  34                       unsigned int mode)
  35 {
  36         struct mei_device *bus;
  37         struct mei_cl_cb *cb;
  38         ssize_t rets;
  39 
  40         if (WARN_ON(!cl || !cl->dev))
  41                 return -ENODEV;
  42 
  43         bus = cl->dev;
  44 
  45         mutex_lock(&bus->device_lock);
  46         if (bus->dev_state != MEI_DEV_ENABLED) {
  47                 rets = -ENODEV;
  48                 goto out;
  49         }
  50 
  51         if (!mei_cl_is_connected(cl)) {
  52                 rets = -ENODEV;
  53                 goto out;
  54         }
  55 
  56         /* Check if we have an ME client device */
  57         if (!mei_me_cl_is_active(cl->me_cl)) {
  58                 rets = -ENOTTY;
  59                 goto out;
  60         }
  61 
  62         if (length > mei_cl_mtu(cl)) {
  63                 rets = -EFBIG;
  64                 goto out;
  65         }
  66 
  67         while (cl->tx_cb_queued >= bus->tx_queue_limit) {
  68                 mutex_unlock(&bus->device_lock);
  69                 rets = wait_event_interruptible(cl->tx_wait,
  70                                 cl->writing_state == MEI_WRITE_COMPLETE ||
  71                                 (!mei_cl_is_connected(cl)));
  72                 mutex_lock(&bus->device_lock);
  73                 if (rets) {
  74                         if (signal_pending(current))
  75                                 rets = -EINTR;
  76                         goto out;
  77                 }
  78                 if (!mei_cl_is_connected(cl)) {
  79                         rets = -ENODEV;
  80                         goto out;
  81                 }
  82         }
  83 
  84         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
  85         if (!cb) {
  86                 rets = -ENOMEM;
  87                 goto out;
  88         }
  89 
  90         cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
  91         cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
  92         memcpy(cb->buf.data, buf, length);
  93 
  94         rets = mei_cl_write(cl, cb);
  95 
  96 out:
  97         mutex_unlock(&bus->device_lock);
  98 
  99         return rets;
 100 }
 101 
 102 /**
 103  * __mei_cl_recv - internal client receive (read)
 104  *
 105  * @cl: host client
 106  * @buf: buffer to receive
 107  * @length: buffer length
 108  * @mode: io mode
 109  * @timeout: recv timeout, 0 for infinite timeout
 110  *
 111  * Return: read size in bytes of < 0 on error
 112  */
 113 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
 114                       unsigned int mode, unsigned long timeout)
 115 {
 116         struct mei_device *bus;
 117         struct mei_cl_cb *cb;
 118         size_t r_length;
 119         ssize_t rets;
 120         bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
 121 
 122         if (WARN_ON(!cl || !cl->dev))
 123                 return -ENODEV;
 124 
 125         bus = cl->dev;
 126 
 127         mutex_lock(&bus->device_lock);
 128         if (bus->dev_state != MEI_DEV_ENABLED) {
 129                 rets = -ENODEV;
 130                 goto out;
 131         }
 132 
 133         cb = mei_cl_read_cb(cl, NULL);
 134         if (cb)
 135                 goto copy;
 136 
 137         rets = mei_cl_read_start(cl, length, NULL);
 138         if (rets && rets != -EBUSY)
 139                 goto out;
 140 
 141         if (nonblock) {
 142                 rets = -EAGAIN;
 143                 goto out;
 144         }
 145 
 146         /* wait on event only if there is no other waiter */
 147         /* synchronized under device mutex */
 148         if (!waitqueue_active(&cl->rx_wait)) {
 149 
 150                 mutex_unlock(&bus->device_lock);
 151 
 152                 if (timeout) {
 153                         rets = wait_event_interruptible_timeout
 154                                         (cl->rx_wait,
 155                                         (!list_empty(&cl->rd_completed)) ||
 156                                         (!mei_cl_is_connected(cl)),
 157                                         msecs_to_jiffies(timeout));
 158                         if (rets == 0)
 159                                 return -ETIME;
 160                         if (rets < 0) {
 161                                 if (signal_pending(current))
 162                                         return -EINTR;
 163                                 return -ERESTARTSYS;
 164                         }
 165                 } else {
 166                         if (wait_event_interruptible
 167                                         (cl->rx_wait,
 168                                         (!list_empty(&cl->rd_completed)) ||
 169                                         (!mei_cl_is_connected(cl)))) {
 170                                 if (signal_pending(current))
 171                                         return -EINTR;
 172                                 return -ERESTARTSYS;
 173                         }
 174                 }
 175 
 176                 mutex_lock(&bus->device_lock);
 177 
 178                 if (!mei_cl_is_connected(cl)) {
 179                         rets = -ENODEV;
 180                         goto out;
 181                 }
 182         }
 183 
 184         cb = mei_cl_read_cb(cl, NULL);
 185         if (!cb) {
 186                 rets = 0;
 187                 goto out;
 188         }
 189 
 190 copy:
 191         if (cb->status) {
 192                 rets = cb->status;
 193                 goto free;
 194         }
 195 
 196         r_length = min_t(size_t, length, cb->buf_idx);
 197         memcpy(buf, cb->buf.data, r_length);
 198         rets = r_length;
 199 
 200 free:
 201         mei_io_cb_free(cb);
 202 out:
 203         mutex_unlock(&bus->device_lock);
 204 
 205         return rets;
 206 }
 207 
 208 /**
 209  * mei_cldev_send - me device send  (write)
 210  *
 211  * @cldev: me client device
 212  * @buf: buffer to send
 213  * @length: buffer length
 214  *
 215  * Return: written size in bytes or < 0 on error
 216  */
 217 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
 218 {
 219         struct mei_cl *cl = cldev->cl;
 220 
 221         return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
 222 }
 223 EXPORT_SYMBOL_GPL(mei_cldev_send);
 224 
 225 /**
 226  * mei_cldev_recv_nonblock - non block client receive (read)
 227  *
 228  * @cldev: me client device
 229  * @buf: buffer to receive
 230  * @length: buffer length
 231  *
 232  * Return: read size in bytes of < 0 on error
 233  *         -EAGAIN if function will block.
 234  */
 235 ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
 236                                 size_t length)
 237 {
 238         struct mei_cl *cl = cldev->cl;
 239 
 240         return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
 241 }
 242 EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
 243 
 244 /**
 245  * mei_cldev_recv - client receive (read)
 246  *
 247  * @cldev: me client device
 248  * @buf: buffer to receive
 249  * @length: buffer length
 250  *
 251  * Return: read size in bytes of < 0 on error
 252  */
 253 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 254 {
 255         struct mei_cl *cl = cldev->cl;
 256 
 257         return __mei_cl_recv(cl, buf, length, 0, 0);
 258 }
 259 EXPORT_SYMBOL_GPL(mei_cldev_recv);
 260 
 261 /**
 262  * mei_cl_bus_rx_work - dispatch rx event for a bus device
 263  *
 264  * @work: work
 265  */
 266 static void mei_cl_bus_rx_work(struct work_struct *work)
 267 {
 268         struct mei_cl_device *cldev;
 269         struct mei_device *bus;
 270 
 271         cldev = container_of(work, struct mei_cl_device, rx_work);
 272 
 273         bus = cldev->bus;
 274 
 275         if (cldev->rx_cb)
 276                 cldev->rx_cb(cldev);
 277 
 278         mutex_lock(&bus->device_lock);
 279         mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 280         mutex_unlock(&bus->device_lock);
 281 }
 282 
 283 /**
 284  * mei_cl_bus_notif_work - dispatch FW notif event for a bus device
 285  *
 286  * @work: work
 287  */
 288 static void mei_cl_bus_notif_work(struct work_struct *work)
 289 {
 290         struct mei_cl_device *cldev;
 291 
 292         cldev = container_of(work, struct mei_cl_device, notif_work);
 293 
 294         if (cldev->notif_cb)
 295                 cldev->notif_cb(cldev);
 296 }
 297 
 298 /**
 299  * mei_cl_bus_notify_event - schedule notify cb on bus client
 300  *
 301  * @cl: host client
 302  *
 303  * Return: true if event was scheduled
 304  *         false if the client is not waiting for event
 305  */
 306 bool mei_cl_bus_notify_event(struct mei_cl *cl)
 307 {
 308         struct mei_cl_device *cldev = cl->cldev;
 309 
 310         if (!cldev || !cldev->notif_cb)
 311                 return false;
 312 
 313         if (!cl->notify_ev)
 314                 return false;
 315 
 316         schedule_work(&cldev->notif_work);
 317 
 318         cl->notify_ev = false;
 319 
 320         return true;
 321 }
 322 
 323 /**
 324  * mei_cl_bus_rx_event - schedule rx event
 325  *
 326  * @cl: host client
 327  *
 328  * Return: true if event was scheduled
 329  *         false if the client is not waiting for event
 330  */
 331 bool mei_cl_bus_rx_event(struct mei_cl *cl)
 332 {
 333         struct mei_cl_device *cldev = cl->cldev;
 334 
 335         if (!cldev || !cldev->rx_cb)
 336                 return false;
 337 
 338         schedule_work(&cldev->rx_work);
 339 
 340         return true;
 341 }
 342 
 343 /**
 344  * mei_cldev_register_rx_cb - register Rx event callback
 345  *
 346  * @cldev: me client devices
 347  * @rx_cb: callback function
 348  *
 349  * Return: 0 on success
 350  *         -EALREADY if an callback is already registered
 351  *         <0 on other errors
 352  */
 353 int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
 354 {
 355         struct mei_device *bus = cldev->bus;
 356         int ret;
 357 
 358         if (!rx_cb)
 359                 return -EINVAL;
 360         if (cldev->rx_cb)
 361                 return -EALREADY;
 362 
 363         cldev->rx_cb = rx_cb;
 364         INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
 365 
 366         mutex_lock(&bus->device_lock);
 367         ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 368         mutex_unlock(&bus->device_lock);
 369         if (ret && ret != -EBUSY)
 370                 return ret;
 371 
 372         return 0;
 373 }
 374 EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
 375 
 376 /**
 377  * mei_cldev_register_notif_cb - register FW notification event callback
 378  *
 379  * @cldev: me client devices
 380  * @notif_cb: callback function
 381  *
 382  * Return: 0 on success
 383  *         -EALREADY if an callback is already registered
 384  *         <0 on other errors
 385  */
 386 int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
 387                                 mei_cldev_cb_t notif_cb)
 388 {
 389         struct mei_device *bus = cldev->bus;
 390         int ret;
 391 
 392         if (!notif_cb)
 393                 return -EINVAL;
 394 
 395         if (cldev->notif_cb)
 396                 return -EALREADY;
 397 
 398         cldev->notif_cb = notif_cb;
 399         INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
 400 
 401         mutex_lock(&bus->device_lock);
 402         ret = mei_cl_notify_request(cldev->cl, NULL, 1);
 403         mutex_unlock(&bus->device_lock);
 404         if (ret)
 405                 return ret;
 406 
 407         return 0;
 408 }
 409 EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
 410 
 411 /**
 412  * mei_cldev_get_drvdata - driver data getter
 413  *
 414  * @cldev: mei client device
 415  *
 416  * Return: driver private data
 417  */
 418 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
 419 {
 420         return dev_get_drvdata(&cldev->dev);
 421 }
 422 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
 423 
 424 /**
 425  * mei_cldev_set_drvdata - driver data setter
 426  *
 427  * @cldev: mei client device
 428  * @data: data to store
 429  */
 430 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
 431 {
 432         dev_set_drvdata(&cldev->dev, data);
 433 }
 434 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
 435 
 436 /**
 437  * mei_cldev_uuid - return uuid of the underlying me client
 438  *
 439  * @cldev: mei client device
 440  *
 441  * Return: me client uuid
 442  */
 443 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
 444 {
 445         return mei_me_cl_uuid(cldev->me_cl);
 446 }
 447 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
 448 
 449 /**
 450  * mei_cldev_ver - return protocol version of the underlying me client
 451  *
 452  * @cldev: mei client device
 453  *
 454  * Return: me client protocol version
 455  */
 456 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
 457 {
 458         return mei_me_cl_ver(cldev->me_cl);
 459 }
 460 EXPORT_SYMBOL_GPL(mei_cldev_ver);
 461 
 462 /**
 463  * mei_cldev_enabled - check whether the device is enabled
 464  *
 465  * @cldev: mei client device
 466  *
 467  * Return: true if me client is initialized and connected
 468  */
 469 bool mei_cldev_enabled(struct mei_cl_device *cldev)
 470 {
 471         return mei_cl_is_connected(cldev->cl);
 472 }
 473 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
 474 
 475 /**
 476  * mei_cl_bus_module_get - acquire module of the underlying
 477  *    hw driver.
 478  *
 479  * @cldev: mei client device
 480  *
 481  * Return: true on success; false if the module was removed.
 482  */
 483 static bool mei_cl_bus_module_get(struct mei_cl_device *cldev)
 484 {
 485         return try_module_get(cldev->bus->dev->driver->owner);
 486 }
 487 
 488 /**
 489  * mei_cl_bus_module_put -  release the underlying hw module.
 490  *
 491  * @cldev: mei client device
 492  */
 493 static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
 494 {
 495         module_put(cldev->bus->dev->driver->owner);
 496 }
 497 
 498 /**
 499  * mei_cldev_enable - enable me client device
 500  *     create connection with me client
 501  *
 502  * @cldev: me client device
 503  *
 504  * Return: 0 on success and < 0 on error
 505  */
 506 int mei_cldev_enable(struct mei_cl_device *cldev)
 507 {
 508         struct mei_device *bus = cldev->bus;
 509         struct mei_cl *cl;
 510         int ret;
 511 
 512         cl = cldev->cl;
 513 
 514         mutex_lock(&bus->device_lock);
 515         if (cl->state == MEI_FILE_UNINITIALIZED) {
 516                 ret = mei_cl_link(cl);
 517                 if (ret)
 518                         goto out;
 519                 /* update pointers */
 520                 cl->cldev = cldev;
 521         }
 522 
 523         if (mei_cl_is_connected(cl)) {
 524                 ret = 0;
 525                 goto out;
 526         }
 527 
 528         if (!mei_me_cl_is_active(cldev->me_cl)) {
 529                 dev_err(&cldev->dev, "me client is not active\n");
 530                 ret = -ENOTTY;
 531                 goto out;
 532         }
 533 
 534         ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 535         if (ret < 0)
 536                 dev_err(&cldev->dev, "cannot connect\n");
 537 
 538 out:
 539         mutex_unlock(&bus->device_lock);
 540 
 541         return ret;
 542 }
 543 EXPORT_SYMBOL_GPL(mei_cldev_enable);
 544 
 545 /**
 546  * mei_cldev_unregister_callbacks - internal wrapper for unregistering
 547  *  callbacks.
 548  *
 549  * @cldev: client device
 550  */
 551 static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
 552 {
 553         if (cldev->rx_cb) {
 554                 cancel_work_sync(&cldev->rx_work);
 555                 cldev->rx_cb = NULL;
 556         }
 557 
 558         if (cldev->notif_cb) {
 559                 cancel_work_sync(&cldev->notif_work);
 560                 cldev->notif_cb = NULL;
 561         }
 562 }
 563 
 564 /**
 565  * mei_cldev_disable - disable me client device
 566  *     disconnect form the me client
 567  *
 568  * @cldev: me client device
 569  *
 570  * Return: 0 on success and < 0 on error
 571  */
 572 int mei_cldev_disable(struct mei_cl_device *cldev)
 573 {
 574         struct mei_device *bus;
 575         struct mei_cl *cl;
 576         int err;
 577 
 578         if (!cldev)
 579                 return -ENODEV;
 580 
 581         cl = cldev->cl;
 582 
 583         bus = cldev->bus;
 584 
 585         mei_cldev_unregister_callbacks(cldev);
 586 
 587         mutex_lock(&bus->device_lock);
 588 
 589         if (!mei_cl_is_connected(cl)) {
 590                 dev_dbg(bus->dev, "Already disconnected\n");
 591                 err = 0;
 592                 goto out;
 593         }
 594 
 595         err = mei_cl_disconnect(cl);
 596         if (err < 0)
 597                 dev_err(bus->dev, "Could not disconnect from the ME client\n");
 598 
 599 out:
 600         /* Flush queues and remove any pending read */
 601         mei_cl_flush_queues(cl, NULL);
 602         mei_cl_unlink(cl);
 603 
 604         mutex_unlock(&bus->device_lock);
 605         return err;
 606 }
 607 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 608 
 609 /**
 610  * mei_cl_device_find - find matching entry in the driver id table
 611  *
 612  * @cldev: me client device
 613  * @cldrv: me client driver
 614  *
 615  * Return: id on success; NULL if no id is matching
 616  */
 617 static const
 618 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 619                                             struct mei_cl_driver *cldrv)
 620 {
 621         const struct mei_cl_device_id *id;
 622         const uuid_le *uuid;
 623         u8 version;
 624         bool match;
 625 
 626         uuid = mei_me_cl_uuid(cldev->me_cl);
 627         version = mei_me_cl_ver(cldev->me_cl);
 628 
 629         id = cldrv->id_table;
 630         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 631                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 632                         match = true;
 633 
 634                         if (cldev->name[0])
 635                                 if (strncmp(cldev->name, id->name,
 636                                             sizeof(id->name)))
 637                                         match = false;
 638 
 639                         if (id->version != MEI_CL_VERSION_ANY)
 640                                 if (id->version != version)
 641                                         match = false;
 642                         if (match)
 643                                 return id;
 644                 }
 645 
 646                 id++;
 647         }
 648 
 649         return NULL;
 650 }
 651 
 652 /**
 653  * mei_cl_device_match  - device match function
 654  *
 655  * @dev: device
 656  * @drv: driver
 657  *
 658  * Return:  1 if matching device was found 0 otherwise
 659  */
 660 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 661 {
 662         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 663         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 664         const struct mei_cl_device_id *found_id;
 665 
 666         if (!cldev)
 667                 return 0;
 668 
 669         if (!cldev->do_match)
 670                 return 0;
 671 
 672         if (!cldrv || !cldrv->id_table)
 673                 return 0;
 674 
 675         found_id = mei_cl_device_find(cldev, cldrv);
 676         if (found_id)
 677                 return 1;
 678 
 679         return 0;
 680 }
 681 
 682 /**
 683  * mei_cl_device_probe - bus probe function
 684  *
 685  * @dev: device
 686  *
 687  * Return:  0 on success; < 0 otherwise
 688  */
 689 static int mei_cl_device_probe(struct device *dev)
 690 {
 691         struct mei_cl_device *cldev;
 692         struct mei_cl_driver *cldrv;
 693         const struct mei_cl_device_id *id;
 694         int ret;
 695 
 696         cldev = to_mei_cl_device(dev);
 697         cldrv = to_mei_cl_driver(dev->driver);
 698 
 699         if (!cldev)
 700                 return 0;
 701 
 702         if (!cldrv || !cldrv->probe)
 703                 return -ENODEV;
 704 
 705         id = mei_cl_device_find(cldev, cldrv);
 706         if (!id)
 707                 return -ENODEV;
 708 
 709         if (!mei_cl_bus_module_get(cldev)) {
 710                 dev_err(&cldev->dev, "get hw module failed");
 711                 return -ENODEV;
 712         }
 713 
 714         ret = cldrv->probe(cldev, id);
 715         if (ret) {
 716                 mei_cl_bus_module_put(cldev);
 717                 return ret;
 718         }
 719 
 720         __module_get(THIS_MODULE);
 721         return 0;
 722 }
 723 
 724 /**
 725  * mei_cl_device_remove - remove device from the bus
 726  *
 727  * @dev: device
 728  *
 729  * Return:  0 on success; < 0 otherwise
 730  */
 731 static int mei_cl_device_remove(struct device *dev)
 732 {
 733         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 734         struct mei_cl_driver *cldrv;
 735         int ret = 0;
 736 
 737         if (!cldev || !dev->driver)
 738                 return 0;
 739 
 740         cldrv = to_mei_cl_driver(dev->driver);
 741         if (cldrv->remove)
 742                 ret = cldrv->remove(cldev);
 743 
 744         mei_cldev_unregister_callbacks(cldev);
 745 
 746         mei_cl_bus_module_put(cldev);
 747         module_put(THIS_MODULE);
 748         dev->driver = NULL;
 749         return ret;
 750 
 751 }
 752 
 753 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 754                              char *buf)
 755 {
 756         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 757 
 758         return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
 759 }
 760 static DEVICE_ATTR_RO(name);
 761 
 762 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 763                              char *buf)
 764 {
 765         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 766         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 767 
 768         return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
 769 }
 770 static DEVICE_ATTR_RO(uuid);
 771 
 772 static ssize_t version_show(struct device *dev, struct device_attribute *a,
 773                              char *buf)
 774 {
 775         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 776         u8 version = mei_me_cl_ver(cldev->me_cl);
 777 
 778         return scnprintf(buf, PAGE_SIZE, "%02X", version);
 779 }
 780 static DEVICE_ATTR_RO(version);
 781 
 782 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 783                              char *buf)
 784 {
 785         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 786         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 787         u8 version = mei_me_cl_ver(cldev->me_cl);
 788 
 789         return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
 790                          cldev->name, uuid, version);
 791 }
 792 static DEVICE_ATTR_RO(modalias);
 793 
 794 static struct attribute *mei_cldev_attrs[] = {
 795         &dev_attr_name.attr,
 796         &dev_attr_uuid.attr,
 797         &dev_attr_version.attr,
 798         &dev_attr_modalias.attr,
 799         NULL,
 800 };
 801 ATTRIBUTE_GROUPS(mei_cldev);
 802 
 803 /**
 804  * mei_cl_device_uevent - me client bus uevent handler
 805  *
 806  * @dev: device
 807  * @env: uevent kobject
 808  *
 809  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 810  */
 811 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 812 {
 813         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 814         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 815         u8 version = mei_me_cl_ver(cldev->me_cl);
 816 
 817         if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
 818                 return -ENOMEM;
 819 
 820         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 821                 return -ENOMEM;
 822 
 823         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 824                 return -ENOMEM;
 825 
 826         if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
 827                            cldev->name, uuid, version))
 828                 return -ENOMEM;
 829 
 830         return 0;
 831 }
 832 
 833 static struct bus_type mei_cl_bus_type = {
 834         .name           = "mei",
 835         .dev_groups     = mei_cldev_groups,
 836         .match          = mei_cl_device_match,
 837         .probe          = mei_cl_device_probe,
 838         .remove         = mei_cl_device_remove,
 839         .uevent         = mei_cl_device_uevent,
 840 };
 841 
 842 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 843 {
 844         if (bus)
 845                 get_device(bus->dev);
 846 
 847         return bus;
 848 }
 849 
 850 static void mei_dev_bus_put(struct mei_device *bus)
 851 {
 852         if (bus)
 853                 put_device(bus->dev);
 854 }
 855 
 856 static void mei_cl_bus_dev_release(struct device *dev)
 857 {
 858         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 859 
 860         if (!cldev)
 861                 return;
 862 
 863         mei_me_cl_put(cldev->me_cl);
 864         mei_dev_bus_put(cldev->bus);
 865         mei_cl_unlink(cldev->cl);
 866         kfree(cldev->cl);
 867         kfree(cldev);
 868 }
 869 
 870 static const struct device_type mei_cl_device_type = {
 871         .release = mei_cl_bus_dev_release,
 872 };
 873 
 874 /**
 875  * mei_cl_bus_set_name - set device name for me client device
 876  *  <controller>-<client device>
 877  *  Example: 0000:00:16.0-55213584-9a29-4916-badf-0fb7ed682aeb
 878  *
 879  * @cldev: me client device
 880  */
 881 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
 882 {
 883         dev_set_name(&cldev->dev, "%s-%pUl",
 884                      dev_name(cldev->bus->dev),
 885                      mei_me_cl_uuid(cldev->me_cl));
 886 }
 887 
 888 /**
 889  * mei_cl_bus_dev_alloc - initialize and allocate mei client device
 890  *
 891  * @bus: mei device
 892  * @me_cl: me client
 893  *
 894  * Return: allocated device structur or NULL on allocation failure
 895  */
 896 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 897                                                   struct mei_me_client *me_cl)
 898 {
 899         struct mei_cl_device *cldev;
 900         struct mei_cl *cl;
 901 
 902         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 903         if (!cldev)
 904                 return NULL;
 905 
 906         cl = mei_cl_allocate(bus);
 907         if (!cl) {
 908                 kfree(cldev);
 909                 return NULL;
 910         }
 911 
 912         device_initialize(&cldev->dev);
 913         cldev->dev.parent = bus->dev;
 914         cldev->dev.bus    = &mei_cl_bus_type;
 915         cldev->dev.type   = &mei_cl_device_type;
 916         cldev->bus        = mei_dev_bus_get(bus);
 917         cldev->me_cl      = mei_me_cl_get(me_cl);
 918         cldev->cl         = cl;
 919         mei_cl_bus_set_name(cldev);
 920         cldev->is_added   = 0;
 921         INIT_LIST_HEAD(&cldev->bus_list);
 922 
 923         return cldev;
 924 }
 925 
 926 /**
 927  * mei_cl_dev_setup - setup me client device
 928  *    run fix up routines and set the device name
 929  *
 930  * @bus: mei device
 931  * @cldev: me client device
 932  *
 933  * Return: true if the device is eligible for enumeration
 934  */
 935 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
 936                                  struct mei_cl_device *cldev)
 937 {
 938         cldev->do_match = 1;
 939         mei_cl_bus_dev_fixup(cldev);
 940 
 941         /* the device name can change during fix up */
 942         if (cldev->do_match)
 943                 mei_cl_bus_set_name(cldev);
 944 
 945         return cldev->do_match == 1;
 946 }
 947 
 948 /**
 949  * mei_cl_bus_dev_add - add me client devices
 950  *
 951  * @cldev: me client device
 952  *
 953  * Return: 0 on success; < 0 on failre
 954  */
 955 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 956 {
 957         int ret;
 958 
 959         dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
 960                 mei_me_cl_uuid(cldev->me_cl),
 961                 mei_me_cl_ver(cldev->me_cl));
 962         ret = device_add(&cldev->dev);
 963         if (!ret)
 964                 cldev->is_added = 1;
 965 
 966         return ret;
 967 }
 968 
 969 /**
 970  * mei_cl_bus_dev_stop - stop the driver
 971  *
 972  * @cldev: me client device
 973  */
 974 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
 975 {
 976         if (cldev->is_added)
 977                 device_release_driver(&cldev->dev);
 978 }
 979 
 980 /**
 981  * mei_cl_bus_dev_destroy - destroy me client devices object
 982  *
 983  * @cldev: me client device
 984  *
 985  * Locking: called under "dev->cl_bus_lock" lock
 986  */
 987 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
 988 {
 989 
 990         WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
 991 
 992         if (!cldev->is_added)
 993                 return;
 994 
 995         device_del(&cldev->dev);
 996 
 997         list_del_init(&cldev->bus_list);
 998 
 999         cldev->is_added = 0;
1000         put_device(&cldev->dev);
1001 }
1002 
1003 /**
1004  * mei_cl_bus_remove_device - remove a devices form the bus
1005  *
1006  * @cldev: me client device
1007  */
1008 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
1009 {
1010         mei_cl_bus_dev_stop(cldev);
1011         mei_cl_bus_dev_destroy(cldev);
1012 }
1013 
1014 /**
1015  * mei_cl_bus_remove_devices - remove all devices form the bus
1016  *
1017  * @bus: mei device
1018  */
1019 void mei_cl_bus_remove_devices(struct mei_device *bus)
1020 {
1021         struct mei_cl_device *cldev, *next;
1022 
1023         mutex_lock(&bus->cl_bus_lock);
1024         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1025                 mei_cl_bus_remove_device(cldev);
1026         mutex_unlock(&bus->cl_bus_lock);
1027 }
1028 
1029 
1030 /**
1031  * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1032  *     based on me client
1033  *
1034  * @bus: mei device
1035  * @me_cl: me client
1036  *
1037  * Locking: called under "dev->cl_bus_lock" lock
1038  */
1039 static void mei_cl_bus_dev_init(struct mei_device *bus,
1040                                 struct mei_me_client *me_cl)
1041 {
1042         struct mei_cl_device *cldev;
1043 
1044         WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1045 
1046         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1047 
1048         if (me_cl->bus_added)
1049                 return;
1050 
1051         cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1052         if (!cldev)
1053                 return;
1054 
1055         me_cl->bus_added = true;
1056         list_add_tail(&cldev->bus_list, &bus->device_list);
1057 
1058 }
1059 
1060 /**
1061  * mei_cl_bus_rescan - scan me clients list and add create
1062  *    devices for eligible clients
1063  *
1064  * @bus: mei device
1065  */
1066 static void mei_cl_bus_rescan(struct mei_device *bus)
1067 {
1068         struct mei_cl_device *cldev, *n;
1069         struct mei_me_client *me_cl;
1070 
1071         mutex_lock(&bus->cl_bus_lock);
1072 
1073         down_read(&bus->me_clients_rwsem);
1074         list_for_each_entry(me_cl, &bus->me_clients, list)
1075                 mei_cl_bus_dev_init(bus, me_cl);
1076         up_read(&bus->me_clients_rwsem);
1077 
1078         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1079 
1080                 if (!mei_me_cl_is_active(cldev->me_cl)) {
1081                         mei_cl_bus_remove_device(cldev);
1082                         continue;
1083                 }
1084 
1085                 if (cldev->is_added)
1086                         continue;
1087 
1088                 if (mei_cl_bus_dev_setup(bus, cldev))
1089                         mei_cl_bus_dev_add(cldev);
1090                 else {
1091                         list_del_init(&cldev->bus_list);
1092                         put_device(&cldev->dev);
1093                 }
1094         }
1095         mutex_unlock(&bus->cl_bus_lock);
1096 
1097         dev_dbg(bus->dev, "rescan end");
1098 }
1099 
1100 void mei_cl_bus_rescan_work(struct work_struct *work)
1101 {
1102         struct mei_device *bus =
1103                 container_of(work, struct mei_device, bus_rescan_work);
1104 
1105         mei_cl_bus_rescan(bus);
1106 }
1107 
1108 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1109                                 struct module *owner)
1110 {
1111         int err;
1112 
1113         cldrv->driver.name = cldrv->name;
1114         cldrv->driver.owner = owner;
1115         cldrv->driver.bus = &mei_cl_bus_type;
1116 
1117         err = driver_register(&cldrv->driver);
1118         if (err)
1119                 return err;
1120 
1121         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1122 
1123         return 0;
1124 }
1125 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1126 
1127 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1128 {
1129         driver_unregister(&cldrv->driver);
1130 
1131         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1132 }
1133 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1134 
1135 
1136 int __init mei_cl_bus_init(void)
1137 {
1138         return bus_register(&mei_cl_bus_type);
1139 }
1140 
1141 void __exit mei_cl_bus_exit(void)
1142 {
1143         bus_unregister(&mei_cl_bus_type);
1144 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/misc/mei/bus.c

DEFINITIONS
