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         mutex_lock(&bus->device_lock);
 525         if (cl->state == MEI_FILE_UNINITIALIZED) {
 526                 ret = mei_cl_link(cl);
 527                 if (ret)
 528                         goto out;
 529                 /* update pointers */
 530                 cl->cldev = cldev;
 531         }
 532
 533         if (mei_cl_is_connected(cl)) {
 534                 ret = 0;
 535                 goto out;
 536         }
 537
 538         if (!mei_me_cl_is_active(cldev->me_cl)) {
 539                 dev_err(&cldev->dev, "me client is not active\n");
 540                 ret = -ENOTTY;
 541                 goto out;
 542         }
 543
 544         if (!mei_cl_bus_module_get(cldev)) {
 545                 dev_err(&cldev->dev, "get hw module failed");
 546                 ret = -ENODEV;
 547                 goto out;
 548         }
 549
 550         ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 551         if (ret < 0) {
 552                 dev_err(&cldev->dev, "cannot connect\n");
 553                 mei_cl_bus_module_put(cldev);
 554         }
 555
 556 out:
 557         mutex_unlock(&bus->device_lock);
 558
 559         return ret;
 560 }
 561 EXPORT_SYMBOL_GPL(mei_cldev_enable);
 562
 563 /**
 564  * mei_cldev_unregister_callbacks - internal wrapper for unregistering
 565  *  callbacks.
 566  *
 567  * @cldev: client device
 568  */
 569 static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
 570 {
 571         if (cldev->rx_cb) {
 572                 cancel_work_sync(&cldev->rx_work);
 573                 cldev->rx_cb = NULL;
 574         }
 575
 576         if (cldev->notif_cb) {
 577                 cancel_work_sync(&cldev->notif_work);
 578                 cldev->notif_cb = NULL;
 579         }
 580 }
 581
 582 /**
 583  * mei_cldev_disable - disable me client device
 584  *     disconnect form the me client
 585  *
 586  * @cldev: me client device
 587  *
 588  * Return: 0 on success and < 0 on error
 589  */
 590 int mei_cldev_disable(struct mei_cl_device *cldev)
 591 {
 592         struct mei_device *bus;
 593         struct mei_cl *cl;
 594         int err;
 595
 596         if (!cldev)
 597                 return -ENODEV;
 598
 599         cl = cldev->cl;
 600
 601         bus = cldev->bus;
 602
 603         mei_cldev_unregister_callbacks(cldev);
 604
 605         mutex_lock(&bus->device_lock);
 606
 607         if (!mei_cl_is_connected(cl)) {
 608                 dev_dbg(bus->dev, "Already disconnected\n");
 609                 err = 0;
 610                 goto out;
 611         }
 612
 613         err = mei_cl_disconnect(cl);
 614         if (err < 0)
 615                 dev_err(bus->dev, "Could not disconnect from the ME client\n");
 616
 617         mei_cl_bus_module_put(cldev);
 618 out:
 619         /* Flush queues and remove any pending read */
 620         mei_cl_flush_queues(cl, NULL);
 621         mei_cl_unlink(cl);
 622
 623         mutex_unlock(&bus->device_lock);
 624         return err;
 625 }
 626 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 627
 628 /**
 629  * mei_cl_device_find - find matching entry in the driver id table
 630  *
 631  * @cldev: me client device
 632  * @cldrv: me client driver
 633  *
 634  * Return: id on success; NULL if no id is matching
 635  */
 636 static const
 637 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 638                                             struct mei_cl_driver *cldrv)
 639 {
 640         const struct mei_cl_device_id *id;
 641         const uuid_le *uuid;
 642         u8 version;
 643         bool match;
 644
 645         uuid = mei_me_cl_uuid(cldev->me_cl);
 646         version = mei_me_cl_ver(cldev->me_cl);
 647
 648         id = cldrv->id_table;
 649         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 650                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 651                         match = true;
 652
 653                         if (cldev->name[0])
 654                                 if (strncmp(cldev->name, id->name,
 655                                             sizeof(id->name)))
 656                                         match = false;
 657
 658                         if (id->version != MEI_CL_VERSION_ANY)
 659                                 if (id->version != version)
 660                                         match = false;
 661                         if (match)
 662                                 return id;
 663                 }
 664
 665                 id++;
 666         }
 667
 668         return NULL;
 669 }
 670
 671 /**
 672  * mei_cl_device_match  - device match function
 673  *
 674  * @dev: device
 675  * @drv: driver
 676  *
 677  * Return:  1 if matching device was found 0 otherwise
 678  */
 679 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 680 {
 681         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 682         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 683         const struct mei_cl_device_id *found_id;
 684
 685         if (!cldev)
 686                 return 0;
 687
 688         if (!cldev->do_match)
 689                 return 0;
 690
 691         if (!cldrv || !cldrv->id_table)
 692                 return 0;
 693
 694         found_id = mei_cl_device_find(cldev, cldrv);
 695         if (found_id)
 696                 return 1;
 697
 698         return 0;
 699 }
 700
 701 /**
 702  * mei_cl_device_probe - bus probe function
 703  *
 704  * @dev: device
 705  *
 706  * Return:  0 on success; < 0 otherwise
 707  */
 708 static int mei_cl_device_probe(struct device *dev)
 709 {
 710         struct mei_cl_device *cldev;
 711         struct mei_cl_driver *cldrv;
 712         const struct mei_cl_device_id *id;
 713         int ret;
 714
 715         cldev = to_mei_cl_device(dev);
 716         cldrv = to_mei_cl_driver(dev->driver);
 717
 718         if (!cldev)
 719                 return 0;
 720
 721         if (!cldrv || !cldrv->probe)
 722                 return -ENODEV;
 723
 724         id = mei_cl_device_find(cldev, cldrv);
 725         if (!id)
 726                 return -ENODEV;
 727
 728         ret = cldrv->probe(cldev, id);
 729         if (ret)
 730                 return ret;
 731
 732         __module_get(THIS_MODULE);
 733         return 0;
 734 }
 735
 736 /**
 737  * mei_cl_device_remove - remove device from the bus
 738  *
 739  * @dev: device
 740  *
 741  * Return:  0 on success; < 0 otherwise
 742  */
 743 static int mei_cl_device_remove(struct device *dev)
 744 {
 745         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 746         struct mei_cl_driver *cldrv;
 747         int ret = 0;
 748
 749         if (!cldev || !dev->driver)
 750                 return 0;
 751
 752         cldrv = to_mei_cl_driver(dev->driver);
 753         if (cldrv->remove)
 754                 ret = cldrv->remove(cldev);
 755
 756         mei_cldev_unregister_callbacks(cldev);
 757
 758         module_put(THIS_MODULE);
 759         dev->driver = NULL;
 760         return ret;
 761
 762 }
 763
 764 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 765                              char *buf)
 766 {
 767         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 768
 769         return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
 770 }
 771 static DEVICE_ATTR_RO(name);
 772
 773 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 774                              char *buf)
 775 {
 776         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 777         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 778
 779         return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
 780 }
 781 static DEVICE_ATTR_RO(uuid);
 782
 783 static ssize_t version_show(struct device *dev, struct device_attribute *a,
 784                              char *buf)
 785 {
 786         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 787         u8 version = mei_me_cl_ver(cldev->me_cl);
 788
 789         return scnprintf(buf, PAGE_SIZE, "%02X", version);
 790 }
 791 static DEVICE_ATTR_RO(version);
 792
 793 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 794                              char *buf)
 795 {
 796         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 797         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 798         u8 version = mei_me_cl_ver(cldev->me_cl);
 799
 800         return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
 801                          cldev->name, uuid, version);
 802 }
 803 static DEVICE_ATTR_RO(modalias);
 804
 805 static struct attribute *mei_cldev_attrs[] = {
 806         &dev_attr_name.attr,
 807         &dev_attr_uuid.attr,
 808         &dev_attr_version.attr,
 809         &dev_attr_modalias.attr,
 810         NULL,
 811 };
 812 ATTRIBUTE_GROUPS(mei_cldev);
 813
 814 /**
 815  * mei_cl_device_uevent - me client bus uevent handler
 816  *
 817  * @dev: device
 818  * @env: uevent kobject
 819  *
 820  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 821  */
 822 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 823 {
 824         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 825         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 826         u8 version = mei_me_cl_ver(cldev->me_cl);
 827
 828         if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
 829                 return -ENOMEM;
 830
 831         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 832                 return -ENOMEM;
 833
 834         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 835                 return -ENOMEM;
 836
 837         if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
 838                            cldev->name, uuid, version))
 839                 return -ENOMEM;
 840
 841         return 0;
 842 }
 843
 844 static struct bus_type mei_cl_bus_type = {
 845         .name           = "mei",
 846         .dev_groups     = mei_cldev_groups,
 847         .match          = mei_cl_device_match,
 848         .probe          = mei_cl_device_probe,
 849         .remove         = mei_cl_device_remove,
 850         .uevent         = mei_cl_device_uevent,
 851 };
 852
 853 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 854 {
 855         if (bus)
 856                 get_device(bus->dev);
 857
 858         return bus;
 859 }
 860
 861 static void mei_dev_bus_put(struct mei_device *bus)
 862 {
 863         if (bus)
 864                 put_device(bus->dev);
 865 }
 866
 867 static void mei_cl_bus_dev_release(struct device *dev)
 868 {
 869         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 870
 871         if (!cldev)
 872                 return;
 873
 874         mei_me_cl_put(cldev->me_cl);
 875         mei_dev_bus_put(cldev->bus);
 876         mei_cl_unlink(cldev->cl);
 877         kfree(cldev->cl);
 878         kfree(cldev);
 879 }
 880
 881 static const struct device_type mei_cl_device_type = {
 882         .release = mei_cl_bus_dev_release,
 883 };
 884
 885 /**
 886  * mei_cl_bus_set_name - set device name for me client device
 887  *
 888  * @cldev: me client device
 889  */
 890 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
 891 {
 892         dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
 893                      cldev->name,
 894                      mei_me_cl_uuid(cldev->me_cl),
 895                      mei_me_cl_ver(cldev->me_cl));
 896 }
 897
 898 /**
 899  * mei_cl_bus_dev_alloc - initialize and allocate mei client device
 900  *
 901  * @bus: mei device
 902  * @me_cl: me client
 903  *
 904  * Return: allocated device structur or NULL on allocation failure
 905  */
 906 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 907                                                   struct mei_me_client *me_cl)
 908 {
 909         struct mei_cl_device *cldev;
 910         struct mei_cl *cl;
 911
 912         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 913         if (!cldev)
 914                 return NULL;
 915
 916         cl = mei_cl_allocate(bus);
 917         if (!cl) {
 918                 kfree(cldev);
 919                 return NULL;
 920         }
 921
 922         device_initialize(&cldev->dev);
 923         cldev->dev.parent = bus->dev;
 924         cldev->dev.bus    = &mei_cl_bus_type;
 925         cldev->dev.type   = &mei_cl_device_type;
 926         cldev->bus        = mei_dev_bus_get(bus);
 927         cldev->me_cl      = mei_me_cl_get(me_cl);
 928         cldev->cl         = cl;
 929         mei_cl_bus_set_name(cldev);
 930         cldev->is_added   = 0;
 931         INIT_LIST_HEAD(&cldev->bus_list);
 932
 933         return cldev;
 934 }
 935
 936 /**
 937  * mei_cl_dev_setup - setup me client device
 938  *    run fix up routines and set the device name
 939  *
 940  * @bus: mei device
 941  * @cldev: me client device
 942  *
 943  * Return: true if the device is eligible for enumeration
 944  */
 945 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
 946                                  struct mei_cl_device *cldev)
 947 {
 948         cldev->do_match = 1;
 949         mei_cl_bus_dev_fixup(cldev);
 950
 951         /* the device name can change during fix up */
 952         if (cldev->do_match)
 953                 mei_cl_bus_set_name(cldev);
 954
 955         return cldev->do_match == 1;
 956 }
 957
 958 /**
 959  * mei_cl_bus_dev_add - add me client devices
 960  *
 961  * @cldev: me client device
 962  *
 963  * Return: 0 on success; < 0 on failre
 964  */
 965 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 966 {
 967         int ret;
 968
 969         dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
 970                 mei_me_cl_uuid(cldev->me_cl),
 971                 mei_me_cl_ver(cldev->me_cl));
 972         ret = device_add(&cldev->dev);
 973         if (!ret)
 974                 cldev->is_added = 1;
 975
 976         return ret;
 977 }
 978
 979 /**
 980  * mei_cl_bus_dev_stop - stop the driver
 981  *
 982  * @cldev: me client device
 983  */
 984 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
 985 {
 986         if (cldev->is_added)
 987                 device_release_driver(&cldev->dev);
 988 }
 989
 990 /**
 991  * mei_cl_bus_dev_destroy - destroy me client devices object
 992  *
 993  * @cldev: me client device
 994  *
 995  * Locking: called under "dev->cl_bus_lock" lock
 996  */
 997 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
 998 {
 999
1000         WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
1001
1002         if (!cldev->is_added)
1003                 return;
1004
1005         device_del(&cldev->dev);
1006
1007         list_del_init(&cldev->bus_list);
1008
1009         cldev->is_added = 0;
1010         put_device(&cldev->dev);
1011 }
1012
1013 /**
1014  * mei_cl_bus_remove_device - remove a devices form the bus
1015  *
1016  * @cldev: me client device
1017  */
1018 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
1019 {
1020         mei_cl_bus_dev_stop(cldev);
1021         mei_cl_bus_dev_destroy(cldev);
1022 }
1023
1024 /**
1025  * mei_cl_bus_remove_devices - remove all devices form the bus
1026  *
1027  * @bus: mei device
1028  */
1029 void mei_cl_bus_remove_devices(struct mei_device *bus)
1030 {
1031         struct mei_cl_device *cldev, *next;
1032
1033         mutex_lock(&bus->cl_bus_lock);
1034         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1035                 mei_cl_bus_remove_device(cldev);
1036         mutex_unlock(&bus->cl_bus_lock);
1037 }
1038
1039
1040 /**
1041  * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1042  *     based on me client
1043  *
1044  * @bus: mei device
1045  * @me_cl: me client
1046  *
1047  * Locking: called under "dev->cl_bus_lock" lock
1048  */
1049 static void mei_cl_bus_dev_init(struct mei_device *bus,
1050                                 struct mei_me_client *me_cl)
1051 {
1052         struct mei_cl_device *cldev;
1053
1054         WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1055
1056         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1057
1058         if (me_cl->bus_added)
1059                 return;
1060
1061         cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1062         if (!cldev)
1063                 return;
1064
1065         me_cl->bus_added = true;
1066         list_add_tail(&cldev->bus_list, &bus->device_list);
1067
1068 }
1069
1070 /**
1071  * mei_cl_bus_rescan - scan me clients list and add create
1072  *    devices for eligible clients
1073  *
1074  * @bus: mei device
1075  */
1076 static void mei_cl_bus_rescan(struct mei_device *bus)
1077 {
1078         struct mei_cl_device *cldev, *n;
1079         struct mei_me_client *me_cl;
1080
1081         mutex_lock(&bus->cl_bus_lock);
1082
1083         down_read(&bus->me_clients_rwsem);
1084         list_for_each_entry(me_cl, &bus->me_clients, list)
1085                 mei_cl_bus_dev_init(bus, me_cl);
1086         up_read(&bus->me_clients_rwsem);
1087
1088         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1089
1090                 if (!mei_me_cl_is_active(cldev->me_cl)) {
1091                         mei_cl_bus_remove_device(cldev);
1092                         continue;
1093                 }
1094
1095                 if (cldev->is_added)
1096                         continue;
1097
1098                 if (mei_cl_bus_dev_setup(bus, cldev))
1099                         mei_cl_bus_dev_add(cldev);
1100                 else {
1101                         list_del_init(&cldev->bus_list);
1102                         put_device(&cldev->dev);
1103                 }
1104         }
1105         mutex_unlock(&bus->cl_bus_lock);
1106
1107         dev_dbg(bus->dev, "rescan end");
1108 }
1109
1110 void mei_cl_bus_rescan_work(struct work_struct *work)
1111 {
1112         struct mei_device *bus =
1113                 container_of(work, struct mei_device, bus_rescan_work);
1114
1115         mei_cl_bus_rescan(bus);
1116 }
1117
1118 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1119                                 struct module *owner)
1120 {
1121         int err;
1122
1123         cldrv->driver.name = cldrv->name;
1124         cldrv->driver.owner = owner;
1125         cldrv->driver.bus = &mei_cl_bus_type;
1126
1127         err = driver_register(&cldrv->driver);
1128         if (err)
1129                 return err;
1130
1131         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1132
1133         return 0;
1134 }
1135 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1136
1137 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1138 {
1139         driver_unregister(&cldrv->driver);
1140
1141         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1142 }
1143 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1144
1145
1146 int __init mei_cl_bus_init(void)
1147 {
1148         return bus_register(&mei_cl_bus_type);
1149 }
1150
1151 void __exit mei_cl_bus_exit(void)
1152 {
1153         bus_unregister(&mei_cl_bus_type);
1154 }