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