drivers/misc/mei/bus.c

   1 /*
   2  * Intel Management Engine Interface (Intel MEI) Linux driver
   3  * Copyright (c) 2012-2013, Intel 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  */
  15
  16 #include <linux/module.h>
  17 #include <linux/device.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched/signal.h>
  20 #include <linux/init.h>
  21 #include <linux/errno.h>
  22 #include <linux/slab.h>
  23 #include <linux/mutex.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/mei_cl_bus.h>
  26
  27 #include "mei_dev.h"
  28 #include "client.h"
  29
  30 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
  31 #define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
  32
  33 /**
  34  * __mei_cl_send - internal client send (write)
  35  *
  36  * @cl: host client
  37  * @buf: buffer to send
  38  * @length: buffer length
  39  * @mode: sending mode
  40  *
  41  * Return: written size bytes or < 0 on error
  42  */
  43 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
  44                       unsigned int mode)
  45 {
  46         struct mei_device *bus;
  47         struct mei_cl_cb *cb;
  48         ssize_t rets;
  49
  50         if (WARN_ON(!cl || !cl->dev))
  51                 return -ENODEV;
  52
  53         bus = cl->dev;
  54
  55         mutex_lock(&bus->device_lock);
  56         if (bus->dev_state != MEI_DEV_ENABLED) {
  57                 rets = -ENODEV;
  58                 goto out;
  59         }
  60
  61         if (!mei_cl_is_connected(cl)) {
  62                 rets = -ENODEV;
  63                 goto out;
  64         }
  65
  66         /* Check if we have an ME client device */
  67         if (!mei_me_cl_is_active(cl->me_cl)) {
  68                 rets = -ENOTTY;
  69                 goto out;
  70         }
  71
  72         if (length > mei_cl_mtu(cl)) {
  73                 rets = -EFBIG;
  74                 goto out;
  75         }
  76
  77         while (cl->tx_cb_queued >= bus->tx_queue_limit) {
  78                 mutex_unlock(&bus->device_lock);
  79                 rets = wait_event_interruptible(cl->tx_wait,
  80                                 cl->writing_state == MEI_WRITE_COMPLETE ||
  81                                 (!mei_cl_is_connected(cl)));
  82                 mutex_lock(&bus->device_lock);
  83                 if (rets) {
  84                         if (signal_pending(current))
  85                                 rets = -EINTR;
  86                         goto out;
  87                 }
  88                 if (!mei_cl_is_connected(cl)) {
  89                         rets = -ENODEV;
  90                         goto out;
  91                 }
  92         }
  93
  94         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
  95         if (!cb) {
  96                 rets = -ENOMEM;
  97                 goto out;
  98         }
  99
 100         cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
 101         cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
 102         memcpy(cb->buf.data, buf, length);
 103
 104         rets = mei_cl_write(cl, cb);
 105
 106 out:
 107         mutex_unlock(&bus->device_lock);
 108
 109         return rets;
 110 }
 111
 112 /**
 113  * __mei_cl_recv - internal client receive (read)
 114  *
 115  * @cl: host client
 116  * @buf: buffer to receive
 117  * @length: buffer length
 118  * @mode: io mode
 119  * @timeout: recv timeout, 0 for infinite timeout
 120  *
 121  * Return: read size in bytes of < 0 on error
 122  */
 123 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
 124                       unsigned int mode, unsigned long timeout)
 125 {
 126         struct mei_device *bus;
 127         struct mei_cl_cb *cb;
 128         size_t r_length;
 129         ssize_t rets;
 130         bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
 131
 132         if (WARN_ON(!cl || !cl->dev))
 133                 return -ENODEV;
 134
 135         bus = cl->dev;
 136
 137         mutex_lock(&bus->device_lock);
 138         if (bus->dev_state != MEI_DEV_ENABLED) {
 139                 rets = -ENODEV;
 140                 goto out;
 141         }
 142
 143         cb = mei_cl_read_cb(cl, NULL);
 144         if (cb)
 145                 goto copy;
 146
 147         rets = mei_cl_read_start(cl, length, NULL);
 148         if (rets && rets != -EBUSY)
 149                 goto out;
 150
 151         if (nonblock) {
 152                 rets = -EAGAIN;
 153                 goto out;
 154         }
 155
 156         /* wait on event only if there is no other waiter */
 157         /* synchronized under device mutex */
 158         if (!waitqueue_active(&cl->rx_wait)) {
 159
 160                 mutex_unlock(&bus->device_lock);
 161
 162                 if (timeout) {
 163                         rets = wait_event_interruptible_timeout
 164                                         (cl->rx_wait,
 165                                         (!list_empty(&cl->rd_completed)) ||
 166                                         (!mei_cl_is_connected(cl)),
 167                                         msecs_to_jiffies(timeout));
 168                         if (rets == 0)
 169                                 return -ETIME;
 170                         if (rets < 0) {
 171                                 if (signal_pending(current))
 172                                         return -EINTR;
 173                                 return -ERESTARTSYS;
 174                         }
 175                 } else {
 176                         if (wait_event_interruptible
 177                                         (cl->rx_wait,
 178                                         (!list_empty(&cl->rd_completed)) ||
 179                                         (!mei_cl_is_connected(cl)))) {
 180                                 if (signal_pending(current))
 181                                         return -EINTR;
 182                                 return -ERESTARTSYS;
 183                         }
 184                 }
 185
 186                 mutex_lock(&bus->device_lock);
 187
 188                 if (!mei_cl_is_connected(cl)) {
 189                         rets = -ENODEV;
 190                         goto out;
 191                 }
 192         }
 193
 194         cb = mei_cl_read_cb(cl, NULL);
 195         if (!cb) {
 196                 rets = 0;
 197                 goto out;
 198         }
 199
 200 copy:
 201         if (cb->status) {
 202                 rets = cb->status;
 203                 goto free;
 204         }
 205
 206         r_length = min_t(size_t, length, cb->buf_idx);
 207         memcpy(buf, cb->buf.data, r_length);
 208         rets = r_length;
 209
 210 free:
 211         mei_io_cb_free(cb);
 212 out:
 213         mutex_unlock(&bus->device_lock);
 214
 215         return rets;
 216 }
 217
 218 /**
 219  * mei_cldev_send - me device send  (write)
 220  *
 221  * @cldev: me client device
 222  * @buf: buffer to send
 223  * @length: buffer length
 224  *
 225  * Return: written size in bytes or < 0 on error
 226  */
 227 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
 228 {
 229         struct mei_cl *cl = cldev->cl;
 230
 231         return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
 232 }
 233 EXPORT_SYMBOL_GPL(mei_cldev_send);
 234
 235 /**
 236  * mei_cldev_recv_nonblock - non block client receive (read)
 237  *
 238  * @cldev: me client device
 239  * @buf: buffer to receive
 240  * @length: buffer length
 241  *
 242  * Return: read size in bytes of < 0 on error
 243  *         -EAGAIN if function will block.
 244  */
 245 ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
 246                                 size_t length)
 247 {
 248         struct mei_cl *cl = cldev->cl;
 249
 250         return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
 251 }
 252 EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
 253
 254 /**
 255  * mei_cldev_recv - client receive (read)
 256  *
 257  * @cldev: me client device
 258  * @buf: buffer to receive
 259  * @length: buffer length
 260  *
 261  * Return: read size in bytes of < 0 on error
 262  */
 263 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 264 {
 265         struct mei_cl *cl = cldev->cl;
 266
 267         return __mei_cl_recv(cl, buf, length, 0, 0);
 268 }
 269 EXPORT_SYMBOL_GPL(mei_cldev_recv);
 270
 271 /**
 272  * mei_cl_bus_rx_work - dispatch rx event for a bus device
 273  *
 274  * @work: work
 275  */
 276 static void mei_cl_bus_rx_work(struct work_struct *work)
 277 {
 278         struct mei_cl_device *cldev;
 279         struct mei_device *bus;
 280
 281         cldev = container_of(work, struct mei_cl_device, rx_work);
 282
 283         bus = cldev->bus;
 284
 285         if (cldev->rx_cb)
 286                 cldev->rx_cb(cldev);
 287
 288         mutex_lock(&bus->device_lock);
 289         mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 290         mutex_unlock(&bus->device_lock);
 291 }
 292
 293 /**
 294  * mei_cl_bus_notif_work - dispatch FW notif event for a bus device
 295  *
 296  * @work: work
 297  */
 298 static void mei_cl_bus_notif_work(struct work_struct *work)
 299 {
 300         struct mei_cl_device *cldev;
 301
 302         cldev = container_of(work, struct mei_cl_device, notif_work);
 303
 304         if (cldev->notif_cb)
 305                 cldev->notif_cb(cldev);
 306 }
 307
 308 /**
 309  * mei_cl_bus_notify_event - schedule notify cb on bus client
 310  *
 311  * @cl: host client
 312  *
 313  * Return: true if event was scheduled
 314  *         false if the client is not waiting for event
 315  */
 316 bool mei_cl_bus_notify_event(struct mei_cl *cl)
 317 {
 318         struct mei_cl_device *cldev = cl->cldev;
 319
 320         if (!cldev || !cldev->notif_cb)
 321                 return false;
 322
 323         if (!cl->notify_ev)
 324                 return false;
 325
 326         schedule_work(&cldev->notif_work);
 327
 328         cl->notify_ev = false;
 329
 330         return true;
 331 }
 332
 333 /**
 334  * mei_cl_bus_rx_event - schedule rx event
 335  *
 336  * @cl: host client
 337  *
 338  * Return: true if event was scheduled
 339  *         false if the client is not waiting for event
 340  */
 341 bool mei_cl_bus_rx_event(struct mei_cl *cl)
 342 {
 343         struct mei_cl_device *cldev = cl->cldev;
 344
 345         if (!cldev || !cldev->rx_cb)
 346                 return false;
 347
 348         schedule_work(&cldev->rx_work);
 349
 350         return true;
 351 }
 352
 353 /**
 354  * mei_cldev_register_rx_cb - register Rx event callback
 355  *
 356  * @cldev: me client devices
 357  * @rx_cb: callback function
 358  *
 359  * Return: 0 on success
 360  *         -EALREADY if an callback is already registered
 361  *         <0 on other errors
 362  */
 363 int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
 364 {
 365         struct mei_device *bus = cldev->bus;
 366         int ret;
 367
 368         if (!rx_cb)
 369                 return -EINVAL;
 370         if (cldev->rx_cb)
 371                 return -EALREADY;
 372
 373         cldev->rx_cb = rx_cb;
 374         INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
 375
 376         mutex_lock(&bus->device_lock);
 377         ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 378         mutex_unlock(&bus->device_lock);
 379         if (ret && ret != -EBUSY)
 380                 return ret;
 381
 382         return 0;
 383 }
 384 EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
 385
 386 /**
 387  * mei_cldev_register_notif_cb - register FW notification event callback
 388  *
 389  * @cldev: me client devices
 390  * @notif_cb: callback function
 391  *
 392  * Return: 0 on success
 393  *         -EALREADY if an callback is already registered
 394  *         <0 on other errors
 395  */
 396 int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
 397                                 mei_cldev_cb_t notif_cb)
 398 {
 399         struct mei_device *bus = cldev->bus;
 400         int ret;
 401
 402         if (!notif_cb)
 403                 return -EINVAL;
 404
 405         if (cldev->notif_cb)
 406                 return -EALREADY;
 407
 408         cldev->notif_cb = notif_cb;
 409         INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
 410
 411         mutex_lock(&bus->device_lock);
 412         ret = mei_cl_notify_request(cldev->cl, NULL, 1);
 413         mutex_unlock(&bus->device_lock);
 414         if (ret)
 415                 return ret;
 416
 417         return 0;
 418 }
 419 EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
 420
 421 /**
 422  * mei_cldev_get_drvdata - driver data getter
 423  *
 424  * @cldev: mei client device
 425  *
 426  * Return: driver private data
 427  */
 428 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
 429 {
 430         return dev_get_drvdata(&cldev->dev);
 431 }
 432 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
 433
 434 /**
 435  * mei_cldev_set_drvdata - driver data setter
 436  *
 437  * @cldev: mei client device
 438  * @data: data to store
 439  */
 440 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
 441 {
 442         dev_set_drvdata(&cldev->dev, data);
 443 }
 444 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
 445
 446 /**
 447  * mei_cldev_uuid - return uuid of the underlying me client
 448  *
 449  * @cldev: mei client device
 450  *
 451  * Return: me client uuid
 452  */
 453 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
 454 {
 455         return mei_me_cl_uuid(cldev->me_cl);
 456 }
 457 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
 458
 459 /**
 460  * mei_cldev_ver - return protocol version of the underlying me client
 461  *
 462  * @cldev: mei client device
 463  *
 464  * Return: me client protocol version
 465  */
 466 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
 467 {
 468         return mei_me_cl_ver(cldev->me_cl);
 469 }
 470 EXPORT_SYMBOL_GPL(mei_cldev_ver);
 471
 472 /**
 473  * mei_cldev_enabled - check whether the device is enabled
 474  *
 475  * @cldev: mei client device
 476  *
 477  * Return: true if me client is initialized and connected
 478  */
 479 bool mei_cldev_enabled(struct mei_cl_device *cldev)
 480 {
 481         return mei_cl_is_connected(cldev->cl);
 482 }
 483 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
 484
 485 /**
 486  * mei_cl_bus_module_get - acquire module of the underlying
 487  *    hw driver.
 488  *
 489  * @cldev: mei client device
 490  *
 491  * Return: true on success; false if the module was removed.
 492  */
 493 static bool mei_cl_bus_module_get(struct mei_cl_device *cldev)
 494 {
 495         return try_module_get(cldev->bus->dev->driver->owner);
 496 }
 497
 498 /**
 499  * mei_cl_bus_module_put -  release the underlying hw module.
 500  *
 501  * @cldev: mei client device
 502  */
 503 static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
 504 {
 505         module_put(cldev->bus->dev->driver->owner);
 506 }
 507
 508 /**
 509  * mei_cldev_enable - enable me client device
 510  *     create connection with me client
 511  *
 512  * @cldev: me client device
 513  *
 514  * Return: 0 on success and < 0 on error
 515  */
 516 int mei_cldev_enable(struct mei_cl_device *cldev)
 517 {
 518         struct mei_device *bus = cldev->bus;
 519         struct mei_cl *cl;
 520         int ret;
 521
 522         cl = cldev->cl;
 523
 524         if (cl->state == MEI_FILE_UNINITIALIZED) {
 525                 mutex_lock(&bus->device_lock);
 526                 ret = mei_cl_link(cl);
 527                 mutex_unlock(&bus->device_lock);
 528                 if (ret)
 529                         return ret;
 530                 /* update pointers */
 531                 cl->cldev = cldev;
 532         }
 533
 534         mutex_lock(&bus->device_lock);
 535         if (mei_cl_is_connected(cl)) {
 536                 ret = 0;
 537                 goto out;
 538         }
 539
 540         if (!mei_me_cl_is_active(cldev->me_cl)) {
 541                 dev_err(&cldev->dev, "me client is not active\n");
 542                 ret = -ENOTTY;
 543                 goto out;
 544         }
 545
 546         if (!mei_cl_bus_module_get(cldev)) {
 547                 dev_err(&cldev->dev, "get hw module failed");
 548                 ret = -ENODEV;
 549                 goto out;
 550         }
 551
 552         ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 553         if (ret < 0) {
 554                 dev_err(&cldev->dev, "cannot connect\n");
 555                 mei_cl_bus_module_put(cldev);
 556         }
 557
 558 out:
 559         mutex_unlock(&bus->device_lock);
 560
 561         return ret;
 562 }
 563 EXPORT_SYMBOL_GPL(mei_cldev_enable);
 564
 565 /**
 566  * mei_cldev_unregister_callbacks - internal wrapper for unregistering
 567  *  callbacks.
 568  *
 569  * @cldev: client device
 570  */
 571 static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
 572 {
 573         if (cldev->rx_cb) {
 574                 cancel_work_sync(&cldev->rx_work);
 575                 cldev->rx_cb = NULL;
 576         }
 577
 578         if (cldev->notif_cb) {
 579                 cancel_work_sync(&cldev->notif_work);
 580                 cldev->notif_cb = NULL;
 581         }
 582 }
 583
 584 /**
 585  * mei_cldev_disable - disable me client device
 586  *     disconnect form the me client
 587  *
 588  * @cldev: me client device
 589  *
 590  * Return: 0 on success and < 0 on error
 591  */
 592 int mei_cldev_disable(struct mei_cl_device *cldev)
 593 {
 594         struct mei_device *bus;
 595         struct mei_cl *cl;
 596         int err;
 597
 598         if (!cldev)
 599                 return -ENODEV;
 600
 601         cl = cldev->cl;
 602
 603         bus = cldev->bus;
 604
 605         mei_cldev_unregister_callbacks(cldev);
 606
 607         mutex_lock(&bus->device_lock);
 608
 609         if (!mei_cl_is_connected(cl)) {
 610                 dev_dbg(bus->dev, "Already disconnected\n");
 611                 err = 0;
 612                 goto out;
 613         }
 614
 615         err = mei_cl_disconnect(cl);
 616         if (err < 0)
 617                 dev_err(bus->dev, "Could not disconnect from the ME client\n");
 618
 619         mei_cl_bus_module_put(cldev);
 620 out:
 621         /* Flush queues and remove any pending read */
 622         mei_cl_flush_queues(cl, NULL);
 623         mei_cl_unlink(cl);
 624
 625         mutex_unlock(&bus->device_lock);
 626         return err;
 627 }
 628 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 629
 630 /**
 631  * mei_cl_device_find - find matching entry in the driver id table
 632  *
 633  * @cldev: me client device
 634  * @cldrv: me client driver
 635  *
 636  * Return: id on success; NULL if no id is matching
 637  */
 638 static const
 639 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 640                                             struct mei_cl_driver *cldrv)
 641 {
 642         const struct mei_cl_device_id *id;
 643         const uuid_le *uuid;
 644         u8 version;
 645         bool match;
 646
 647         uuid = mei_me_cl_uuid(cldev->me_cl);
 648         version = mei_me_cl_ver(cldev->me_cl);
 649
 650         id = cldrv->id_table;
 651         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 652                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 653                         match = true;
 654
 655                         if (cldev->name[0])
 656                                 if (strncmp(cldev->name, id->name,
 657                                             sizeof(id->name)))
 658                                         match = false;
 659
 660                         if (id->version != MEI_CL_VERSION_ANY)
 661                                 if (id->version != version)
 662                                         match = false;
 663                         if (match)
 664                                 return id;
 665                 }
 666
 667                 id++;
 668         }
 669
 670         return NULL;
 671 }
 672
 673 /**
 674  * mei_cl_device_match  - device match function
 675  *
 676  * @dev: device
 677  * @drv: driver
 678  *
 679  * Return:  1 if matching device was found 0 otherwise
 680  */
 681 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 682 {
 683         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 684         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 685         const struct mei_cl_device_id *found_id;
 686
 687         if (!cldev)
 688                 return 0;
 689
 690         if (!cldev->do_match)
 691                 return 0;
 692
 693         if (!cldrv || !cldrv->id_table)
 694                 return 0;
 695
 696         found_id = mei_cl_device_find(cldev, cldrv);
 697         if (found_id)
 698                 return 1;
 699
 700         return 0;
 701 }
 702
 703 /**
 704  * mei_cl_device_probe - bus probe function
 705  *
 706  * @dev: device
 707  *
 708  * Return:  0 on success; < 0 otherwise
 709  */
 710 static int mei_cl_device_probe(struct device *dev)
 711 {
 712         struct mei_cl_device *cldev;
 713         struct mei_cl_driver *cldrv;
 714         const struct mei_cl_device_id *id;
 715         int ret;
 716
 717         cldev = to_mei_cl_device(dev);
 718         cldrv = to_mei_cl_driver(dev->driver);
 719
 720         if (!cldev)
 721                 return 0;
 722
 723         if (!cldrv || !cldrv->probe)
 724                 return -ENODEV;
 725
 726         id = mei_cl_device_find(cldev, cldrv);
 727         if (!id)
 728                 return -ENODEV;
 729
 730         ret = cldrv->probe(cldev, id);
 731         if (ret)
 732                 return ret;
 733
 734         __module_get(THIS_MODULE);
 735         return 0;
 736 }
 737
 738 /**
 739  * mei_cl_device_remove - remove device from the bus
 740  *
 741  * @dev: device
 742  *
 743  * Return:  0 on success; < 0 otherwise
 744  */
 745 static int mei_cl_device_remove(struct device *dev)
 746 {
 747         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 748         struct mei_cl_driver *cldrv;
 749         int ret = 0;
 750
 751         if (!cldev || !dev->driver)
 752                 return 0;
 753
 754         cldrv = to_mei_cl_driver(dev->driver);
 755         if (cldrv->remove)
 756                 ret = cldrv->remove(cldev);
 757
 758         mei_cldev_unregister_callbacks(cldev);
 759
 760         module_put(THIS_MODULE);
 761         dev->driver = NULL;
 762         return ret;
 763
 764 }
 765
 766 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 767                              char *buf)
 768 {
 769         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 770
 771         return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
 772 }
 773 static DEVICE_ATTR_RO(name);
 774
 775 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 776                              char *buf)
 777 {
 778         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 779         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 780
 781         return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
 782 }
 783 static DEVICE_ATTR_RO(uuid);
 784
 785 static ssize_t version_show(struct device *dev, struct device_attribute *a,
 786                              char *buf)
 787 {
 788         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 789         u8 version = mei_me_cl_ver(cldev->me_cl);
 790
 791         return scnprintf(buf, PAGE_SIZE, "%02X", version);
 792 }
 793 static DEVICE_ATTR_RO(version);
 794
 795 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 796                              char *buf)
 797 {
 798         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 799         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 800         u8 version = mei_me_cl_ver(cldev->me_cl);
 801
 802         return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
 803                          cldev->name, uuid, version);
 804 }
 805 static DEVICE_ATTR_RO(modalias);
 806
 807 static struct attribute *mei_cldev_attrs[] = {
 808         &dev_attr_name.attr,
 809         &dev_attr_uuid.attr,
 810         &dev_attr_version.attr,
 811         &dev_attr_modalias.attr,
 812         NULL,
 813 };
 814 ATTRIBUTE_GROUPS(mei_cldev);
 815
 816 /**
 817  * mei_cl_device_uevent - me client bus uevent handler
 818  *
 819  * @dev: device
 820  * @env: uevent kobject
 821  *
 822  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 823  */
 824 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 825 {
 826         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 827         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 828         u8 version = mei_me_cl_ver(cldev->me_cl);
 829
 830         if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
 831                 return -ENOMEM;
 832
 833         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 834                 return -ENOMEM;
 835
 836         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 837                 return -ENOMEM;
 838
 839         if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
 840                            cldev->name, uuid, version))
 841                 return -ENOMEM;
 842
 843         return 0;
 844 }
 845
 846 static struct bus_type mei_cl_bus_type = {
 847         .name           = "mei",
 848         .dev_groups     = mei_cldev_groups,
 849         .match          = mei_cl_device_match,
 850         .probe          = mei_cl_device_probe,
 851         .remove         = mei_cl_device_remove,
 852         .uevent         = mei_cl_device_uevent,
 853 };
 854
 855 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 856 {
 857         if (bus)
 858                 get_device(bus->dev);
 859
 860         return bus;
 861 }
 862
 863 static void mei_dev_bus_put(struct mei_device *bus)
 864 {
 865         if (bus)
 866                 put_device(bus->dev);
 867 }
 868
 869 static void mei_cl_bus_dev_release(struct device *dev)
 870 {
 871         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 872
 873         if (!cldev)
 874                 return;
 875
 876         mei_me_cl_put(cldev->me_cl);
 877         mei_dev_bus_put(cldev->bus);
 878         kfree(cldev->cl);
 879         kfree(cldev);
 880 }
 881
 882 static const struct device_type mei_cl_device_type = {
 883         .release        = mei_cl_bus_dev_release,
 884 };
 885
 886 /**
 887  * mei_cl_bus_set_name - set device name for me client device
 888  *
 889  * @cldev: me client device
 890  */
 891 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
 892 {
 893         dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
 894                      cldev->name,
 895                      mei_me_cl_uuid(cldev->me_cl),
 896                      mei_me_cl_ver(cldev->me_cl));
 897 }
 898
 899 /**
 900  * mei_cl_bus_dev_alloc - initialize and allocate mei client device
 901  *
 902  * @bus: mei device
 903  * @me_cl: me client
 904  *
 905  * Return: allocated device structur or NULL on allocation failure
 906  */
 907 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 908                                                   struct mei_me_client *me_cl)
 909 {
 910         struct mei_cl_device *cldev;
 911         struct mei_cl *cl;
 912
 913         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 914         if (!cldev)
 915                 return NULL;
 916
 917         cl = mei_cl_allocate(bus);
 918         if (!cl) {
 919                 kfree(cldev);
 920                 return NULL;
 921         }
 922
 923         device_initialize(&cldev->dev);
 924         cldev->dev.parent = bus->dev;
 925         cldev->dev.bus    = &mei_cl_bus_type;
 926         cldev->dev.type   = &mei_cl_device_type;
 927         cldev->bus        = mei_dev_bus_get(bus);
 928         cldev->me_cl      = mei_me_cl_get(me_cl);
 929         cldev->cl         = cl;
 930         mei_cl_bus_set_name(cldev);
 931         cldev->is_added   = 0;
 932         INIT_LIST_HEAD(&cldev->bus_list);
 933
 934         return cldev;
 935 }
 936
 937 /**
 938  * mei_cl_dev_setup - setup me client device
 939  *    run fix up routines and set the device name
 940  *
 941  * @bus: mei device
 942  * @cldev: me client device
 943  *
 944  * Return: true if the device is eligible for enumeration
 945  */
 946 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
 947                                  struct mei_cl_device *cldev)
 948 {
 949         cldev->do_match = 1;
 950         mei_cl_bus_dev_fixup(cldev);
 951
 952         /* the device name can change during fix up */
 953         if (cldev->do_match)
 954                 mei_cl_bus_set_name(cldev);
 955
 956         return cldev->do_match == 1;
 957 }
 958
 959 /**
 960  * mei_cl_bus_dev_add - add me client devices
 961  *
 962  * @cldev: me client device
 963  *
 964  * Return: 0 on success; < 0 on failre
 965  */
 966 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 967 {
 968         int ret;
 969
 970         dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
 971                 mei_me_cl_uuid(cldev->me_cl),
 972                 mei_me_cl_ver(cldev->me_cl));
 973         ret = device_add(&cldev->dev);
 974         if (!ret)
 975                 cldev->is_added = 1;
 976
 977         return ret;
 978 }
 979
 980 /**
 981  * mei_cl_bus_dev_stop - stop the driver
 982  *
 983  * @cldev: me client device
 984  */
 985 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
 986 {
 987         if (cldev->is_added)
 988                 device_release_driver(&cldev->dev);
 989 }
 990
 991 /**
 992  * mei_cl_bus_dev_destroy - destroy me client devices object
 993  *
 994  * @cldev: me client device
 995  *
 996  * Locking: called under "dev->cl_bus_lock" lock
 997  */
 998 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
 999 {
1000
1001         WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
1002
1003         if (!cldev->is_added)
1004                 return;
1005
1006         device_del(&cldev->dev);
1007
1008         list_del_init(&cldev->bus_list);
1009
1010         cldev->is_added = 0;
1011         put_device(&cldev->dev);
1012 }
1013
1014 /**
1015  * mei_cl_bus_remove_device - remove a devices form the bus
1016  *
1017  * @cldev: me client device
1018  */
1019 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
1020 {
1021         mei_cl_bus_dev_stop(cldev);
1022         mei_cl_bus_dev_destroy(cldev);
1023 }
1024
1025 /**
1026  * mei_cl_bus_remove_devices - remove all devices form the bus
1027  *
1028  * @bus: mei device
1029  */
1030 void mei_cl_bus_remove_devices(struct mei_device *bus)
1031 {
1032         struct mei_cl_device *cldev, *next;
1033
1034         mutex_lock(&bus->cl_bus_lock);
1035         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1036                 mei_cl_bus_remove_device(cldev);
1037         mutex_unlock(&bus->cl_bus_lock);
1038 }
1039
1040
1041 /**
1042  * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1043  *     based on me client
1044  *
1045  * @bus: mei device
1046  * @me_cl: me client
1047  *
1048  * Locking: called under "dev->cl_bus_lock" lock
1049  */
1050 static void mei_cl_bus_dev_init(struct mei_device *bus,
1051                                 struct mei_me_client *me_cl)
1052 {
1053         struct mei_cl_device *cldev;
1054
1055         WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1056
1057         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1058
1059         if (me_cl->bus_added)
1060                 return;
1061
1062         cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1063         if (!cldev)
1064                 return;
1065
1066         me_cl->bus_added = true;
1067         list_add_tail(&cldev->bus_list, &bus->device_list);
1068
1069 }
1070
1071 /**
1072  * mei_cl_bus_rescan - scan me clients list and add create
1073  *    devices for eligible clients
1074  *
1075  * @bus: mei device
1076  */
1077 static void mei_cl_bus_rescan(struct mei_device *bus)
1078 {
1079         struct mei_cl_device *cldev, *n;
1080         struct mei_me_client *me_cl;
1081
1082         mutex_lock(&bus->cl_bus_lock);
1083
1084         down_read(&bus->me_clients_rwsem);
1085         list_for_each_entry(me_cl, &bus->me_clients, list)
1086                 mei_cl_bus_dev_init(bus, me_cl);
1087         up_read(&bus->me_clients_rwsem);
1088
1089         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1090
1091                 if (!mei_me_cl_is_active(cldev->me_cl)) {
1092                         mei_cl_bus_remove_device(cldev);
1093                         continue;
1094                 }
1095
1096                 if (cldev->is_added)
1097                         continue;
1098
1099                 if (mei_cl_bus_dev_setup(bus, cldev))
1100                         mei_cl_bus_dev_add(cldev);
1101                 else {
1102                         list_del_init(&cldev->bus_list);
1103                         put_device(&cldev->dev);
1104                 }
1105         }
1106         mutex_unlock(&bus->cl_bus_lock);
1107
1108         dev_dbg(bus->dev, "rescan end");
1109 }
1110
1111 void mei_cl_bus_rescan_work(struct work_struct *work)
1112 {
1113         struct mei_device *bus =
1114                 container_of(work, struct mei_device, bus_rescan_work);
1115
1116         mei_cl_bus_rescan(bus);
1117 }
1118
1119 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1120                                 struct module *owner)
1121 {
1122         int err;
1123
1124         cldrv->driver.name = cldrv->name;
1125         cldrv->driver.owner = owner;
1126         cldrv->driver.bus = &mei_cl_bus_type;
1127
1128         err = driver_register(&cldrv->driver);
1129         if (err)
1130                 return err;
1131
1132         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1133
1134         return 0;
1135 }
1136 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1137
1138 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1139 {
1140         driver_unregister(&cldrv->driver);
1141
1142         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1143 }
1144 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1145
1146
1147 int __init mei_cl_bus_init(void)
1148 {
1149         return bus_register(&mei_cl_bus_type);
1150 }
1151
1152 void __exit mei_cl_bus_exit(void)
1153 {
1154         bus_unregister(&mei_cl_bus_type);
1155 }