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.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  * @blocking: wait for write completion
  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                         bool blocking)
  45 {
  46         struct mei_device *bus;
  47         struct mei_cl_cb *cb = NULL;
  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 (!mei_cl_is_connected(cl)) {
  57                 rets = -ENODEV;
  58                 goto out;
  59         }
  60
  61         /* Check if we have an ME client device */
  62         if (!mei_me_cl_is_active(cl->me_cl)) {
  63                 rets = -ENOTTY;
  64                 goto out;
  65         }
  66
  67         if (length > mei_cl_mtu(cl)) {
  68                 rets = -EFBIG;
  69                 goto out;
  70         }
  71
  72         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
  73         if (!cb) {
  74                 rets = -ENOMEM;
  75                 goto out;
  76         }
  77
  78         memcpy(cb->buf.data, buf, length);
  79
  80         rets = mei_cl_write(cl, cb, blocking);
  81
  82 out:
  83         mutex_unlock(&bus->device_lock);
  84         if (rets < 0)
  85                 mei_io_cb_free(cb);
  86
  87         return rets;
  88 }
  89
  90 /**
  91  * __mei_cl_recv - internal client receive (read)
  92  *
  93  * @cl: host client
  94  * @buf: buffer to send
  95  * @length: buffer length
  96  *
  97  * Return: read size in bytes of < 0 on error
  98  */
  99 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 100 {
 101         struct mei_device *bus;
 102         struct mei_cl_cb *cb;
 103         size_t r_length;
 104         ssize_t rets;
 105
 106         if (WARN_ON(!cl || !cl->dev))
 107                 return -ENODEV;
 108
 109         bus = cl->dev;
 110
 111         mutex_lock(&bus->device_lock);
 112
 113         cb = mei_cl_read_cb(cl, NULL);
 114         if (cb)
 115                 goto copy;
 116
 117         rets = mei_cl_read_start(cl, length, NULL);
 118         if (rets && rets != -EBUSY)
 119                 goto out;
 120
 121         /* wait on event only if there is no other waiter */
 122         if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
 123
 124                 mutex_unlock(&bus->device_lock);
 125
 126                 if (wait_event_interruptible(cl->rx_wait,
 127                                 (!list_empty(&cl->rd_completed)) ||
 128                                 (!mei_cl_is_connected(cl)))) {
 129
 130                         if (signal_pending(current))
 131                                 return -EINTR;
 132                         return -ERESTARTSYS;
 133                 }
 134
 135                 mutex_lock(&bus->device_lock);
 136
 137                 if (!mei_cl_is_connected(cl)) {
 138                         rets = -EBUSY;
 139                         goto out;
 140                 }
 141         }
 142
 143         cb = mei_cl_read_cb(cl, NULL);
 144         if (!cb) {
 145                 rets = 0;
 146                 goto out;
 147         }
 148
 149 copy:
 150         if (cb->status) {
 151                 rets = cb->status;
 152                 goto free;
 153         }
 154
 155         r_length = min_t(size_t, length, cb->buf_idx);
 156         memcpy(buf, cb->buf.data, r_length);
 157         rets = r_length;
 158
 159 free:
 160         mei_io_cb_free(cb);
 161 out:
 162         mutex_unlock(&bus->device_lock);
 163
 164         return rets;
 165 }
 166
 167 /**
 168  * mei_cl_send - me device send  (write)
 169  *
 170  * @cldev: me client device
 171  * @buf: buffer to send
 172  * @length: buffer length
 173  *
 174  * Return: written size in bytes or < 0 on error
 175  */
 176 ssize_t mei_cl_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
 177 {
 178         struct mei_cl *cl = cldev->cl;
 179
 180         if (cl == NULL)
 181                 return -ENODEV;
 182
 183         return __mei_cl_send(cl, buf, length, 1);
 184 }
 185 EXPORT_SYMBOL_GPL(mei_cl_send);
 186
 187 /**
 188  * mei_cl_recv - client receive (read)
 189  *
 190  * @cldev: me client device
 191  * @buf: buffer to send
 192  * @length: buffer length
 193  *
 194  * Return: read size in bytes of < 0 on error
 195  */
 196 ssize_t mei_cl_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 197 {
 198         struct mei_cl *cl = cldev->cl;
 199
 200         if (cl == NULL)
 201                 return -ENODEV;
 202
 203         return __mei_cl_recv(cl, buf, length);
 204 }
 205 EXPORT_SYMBOL_GPL(mei_cl_recv);
 206
 207 /**
 208  * mei_bus_event_work  - dispatch rx event for a bus device
 209  *    and schedule new work
 210  *
 211  * @work: work
 212  */
 213 static void mei_bus_event_work(struct work_struct *work)
 214 {
 215         struct mei_cl_device *cldev;
 216
 217         cldev = container_of(work, struct mei_cl_device, event_work);
 218
 219         if (cldev->event_cb)
 220                 cldev->event_cb(cldev, cldev->events, cldev->event_context);
 221
 222         cldev->events = 0;
 223
 224         /* Prepare for the next read */
 225         if (cldev->events_mask & BIT(MEI_CL_EVENT_RX))
 226                 mei_cl_read_start(cldev->cl, 0, NULL);
 227 }
 228
 229 /**
 230  * mei_cl_bus_notify_event - schedule notify cb on bus client
 231  *
 232  * @cl: host client
 233  */
 234 void mei_cl_bus_notify_event(struct mei_cl *cl)
 235 {
 236         struct mei_cl_device *cldev = cl->cldev;
 237
 238         if (!cldev || !cldev->event_cb)
 239                 return;
 240
 241         if (!(cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)))
 242                 return;
 243
 244         if (!cl->notify_ev)
 245                 return;
 246
 247         set_bit(MEI_CL_EVENT_NOTIF, &cldev->events);
 248
 249         schedule_work(&cldev->event_work);
 250
 251         cl->notify_ev = false;
 252 }
 253
 254 /**
 255  * mei_cl_bus_rx_event  - schedule rx evenet
 256  *
 257  * @cl: host client
 258  */
 259 void mei_cl_bus_rx_event(struct mei_cl *cl)
 260 {
 261         struct mei_cl_device *cldev = cl->cldev;
 262
 263         if (!cldev || !cldev->event_cb)
 264                 return;
 265
 266         if (!(cldev->events_mask & BIT(MEI_CL_EVENT_RX)))
 267                 return;
 268
 269         set_bit(MEI_CL_EVENT_RX, &cldev->events);
 270
 271         schedule_work(&cldev->event_work);
 272 }
 273
 274 /**
 275  * mei_cl_register_event_cb - register event callback
 276  *
 277  * @cldev: me client devices
 278  * @event_cb: callback function
 279  * @events_mask: requested events bitmask
 280  * @context: driver context data
 281  *
 282  * Return: 0 on success
 283  *         -EALREADY if an callback is already registered
 284  *         <0 on other errors
 285  */
 286 int mei_cl_register_event_cb(struct mei_cl_device *cldev,
 287                           unsigned long events_mask,
 288                           mei_cl_event_cb_t event_cb, void *context)
 289 {
 290         int ret;
 291
 292         if (cldev->event_cb)
 293                 return -EALREADY;
 294
 295         cldev->events = 0;
 296         cldev->events_mask = events_mask;
 297         cldev->event_cb = event_cb;
 298         cldev->event_context = context;
 299         INIT_WORK(&cldev->event_work, mei_bus_event_work);
 300
 301         if (cldev->events_mask & BIT(MEI_CL_EVENT_RX)) {
 302                 ret = mei_cl_read_start(cldev->cl, 0, NULL);
 303                 if (ret && ret != -EBUSY)
 304                         return ret;
 305         }
 306
 307         if (cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)) {
 308                 mutex_lock(&cldev->cl->dev->device_lock);
 309                 ret = mei_cl_notify_request(cldev->cl, NULL, event_cb ? 1 : 0);
 310                 mutex_unlock(&cldev->cl->dev->device_lock);
 311                 if (ret)
 312                         return ret;
 313         }
 314
 315         return 0;
 316 }
 317 EXPORT_SYMBOL_GPL(mei_cl_register_event_cb);
 318
 319 /**
 320  * mei_cl_get_drvdata - driver data getter
 321  *
 322  * @cldev: mei client device
 323  *
 324  * Return: driver private data
 325  */
 326 void *mei_cl_get_drvdata(const struct mei_cl_device *cldev)
 327 {
 328         return dev_get_drvdata(&cldev->dev);
 329 }
 330 EXPORT_SYMBOL_GPL(mei_cl_get_drvdata);
 331
 332 /**
 333  * mei_cl_set_drvdata - driver data setter
 334  *
 335  * @cldev: mei client device
 336  * @data: data to store
 337  */
 338 void mei_cl_set_drvdata(struct mei_cl_device *cldev, void *data)
 339 {
 340         dev_set_drvdata(&cldev->dev, data);
 341 }
 342 EXPORT_SYMBOL_GPL(mei_cl_set_drvdata);
 343
 344 /**
 345  * mei_cl_enable_device - enable me client device
 346  *     create connection with me client
 347  *
 348  * @cldev: me client device
 349  *
 350  * Return: 0 on success and < 0 on error
 351  */
 352 int mei_cl_enable_device(struct mei_cl_device *cldev)
 353 {
 354         struct mei_device *bus = cldev->bus;
 355         struct mei_cl *cl;
 356         int ret;
 357
 358         cl = cldev->cl;
 359
 360         if (!cl) {
 361                 mutex_lock(&bus->device_lock);
 362                 cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
 363                 mutex_unlock(&bus->device_lock);
 364                 if (IS_ERR(cl))
 365                         return PTR_ERR(cl);
 366                 /* update pointers */
 367                 cldev->cl = cl;
 368                 cl->cldev = cldev;
 369         }
 370
 371         mutex_lock(&bus->device_lock);
 372         if (mei_cl_is_connected(cl)) {
 373                 ret = 0;
 374                 goto out;
 375         }
 376
 377         if (!mei_me_cl_is_active(cldev->me_cl)) {
 378                 dev_err(&cldev->dev, "me client is not active\n");
 379                 ret = -ENOTTY;
 380                 goto out;
 381         }
 382
 383         ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 384         if (ret < 0)
 385                 dev_err(&cldev->dev, "cannot connect\n");
 386
 387 out:
 388         mutex_unlock(&bus->device_lock);
 389
 390         return ret;
 391 }
 392 EXPORT_SYMBOL_GPL(mei_cl_enable_device);
 393
 394 /**
 395  * mei_cl_disable_device - disable me client device
 396  *     disconnect form the me client
 397  *
 398  * @cldev: me client device
 399  *
 400  * Return: 0 on success and < 0 on error
 401  */
 402 int mei_cl_disable_device(struct mei_cl_device *cldev)
 403 {
 404         struct mei_device *bus;
 405         struct mei_cl *cl;
 406         int err;
 407
 408         if (!cldev || !cldev->cl)
 409                 return -ENODEV;
 410
 411         cl = cldev->cl;
 412
 413         bus = cldev->bus;
 414
 415         cldev->event_cb = NULL;
 416
 417         mutex_lock(&bus->device_lock);
 418
 419         if (!mei_cl_is_connected(cl)) {
 420                 dev_err(bus->dev, "Already disconnected");
 421                 err = 0;
 422                 goto out;
 423         }
 424
 425         err = mei_cl_disconnect(cl);
 426         if (err < 0)
 427                 dev_err(bus->dev, "Could not disconnect from the ME client");
 428
 429 out:
 430         /* Flush queues and remove any pending read */
 431         mei_cl_flush_queues(cl, NULL);
 432         mei_cl_unlink(cl);
 433
 434         kfree(cl);
 435         cldev->cl = NULL;
 436
 437         mutex_unlock(&bus->device_lock);
 438         return err;
 439 }
 440 EXPORT_SYMBOL_GPL(mei_cl_disable_device);
 441
 442 /**
 443  * mei_cl_device_find - find matching entry in the driver id table
 444  *
 445  * @cldev: me client device
 446  * @cldrv: me client driver
 447  *
 448  * Return: id on success; NULL if no id is matching
 449  */
 450 static const
 451 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 452                                             struct mei_cl_driver *cldrv)
 453 {
 454         const struct mei_cl_device_id *id;
 455         const uuid_le *uuid;
 456
 457         uuid = mei_me_cl_uuid(cldev->me_cl);
 458
 459         id = cldrv->id_table;
 460         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 461                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 462
 463                         if (!cldev->name[0])
 464                                 return id;
 465
 466                         if (!strncmp(cldev->name, id->name, sizeof(id->name)))
 467                                 return id;
 468                 }
 469
 470                 id++;
 471         }
 472
 473         return NULL;
 474 }
 475
 476 /**
 477  * mei_cl_device_match  - device match function
 478  *
 479  * @dev: device
 480  * @drv: driver
 481  *
 482  * Return:  1 if matching device was found 0 otherwise
 483  */
 484 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 485 {
 486         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 487         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 488         const struct mei_cl_device_id *found_id;
 489
 490         if (!cldev)
 491                 return 0;
 492
 493         if (!cldev->do_match)
 494                 return 0;
 495
 496         if (!cldrv || !cldrv->id_table)
 497                 return 0;
 498
 499         found_id = mei_cl_device_find(cldev, cldrv);
 500         if (found_id)
 501                 return 1;
 502
 503         return 0;
 504 }
 505
 506 /**
 507  * mei_cl_device_probe - bus probe function
 508  *
 509  * @dev: device
 510  *
 511  * Return:  0 on success; < 0 otherwise
 512  */
 513 static int mei_cl_device_probe(struct device *dev)
 514 {
 515         struct mei_cl_device *cldev;
 516         struct mei_cl_driver *cldrv;
 517         const struct mei_cl_device_id *id;
 518
 519         cldev = to_mei_cl_device(dev);
 520         cldrv = to_mei_cl_driver(dev->driver);
 521
 522         if (!cldev)
 523                 return 0;
 524
 525         if (!cldrv || !cldrv->probe)
 526                 return -ENODEV;
 527
 528         id = mei_cl_device_find(cldev, cldrv);
 529         if (!id)
 530                 return -ENODEV;
 531
 532         __module_get(THIS_MODULE);
 533
 534         return cldrv->probe(cldev, id);
 535 }
 536
 537 /**
 538  * mei_cl_device_remove - remove device from the bus
 539  *
 540  * @dev: device
 541  *
 542  * Return:  0 on success; < 0 otherwise
 543  */
 544 static int mei_cl_device_remove(struct device *dev)
 545 {
 546         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 547         struct mei_cl_driver *cldrv;
 548         int ret = 0;
 549
 550         if (!cldev || !dev->driver)
 551                 return 0;
 552
 553         if (cldev->event_cb) {
 554                 cldev->event_cb = NULL;
 555                 cancel_work_sync(&cldev->event_work);
 556         }
 557
 558         cldrv = to_mei_cl_driver(dev->driver);
 559         if (cldrv->remove)
 560                 ret = cldrv->remove(cldev);
 561
 562         module_put(THIS_MODULE);
 563         dev->driver = NULL;
 564         return ret;
 565
 566 }
 567
 568 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 569                              char *buf)
 570 {
 571         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 572         size_t len;
 573
 574         len = snprintf(buf, PAGE_SIZE, "%s", cldev->name);
 575
 576         return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 577 }
 578 static DEVICE_ATTR_RO(name);
 579
 580 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 581                              char *buf)
 582 {
 583         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 584         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 585         size_t len;
 586
 587         len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
 588
 589         return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 590 }
 591 static DEVICE_ATTR_RO(uuid);
 592
 593 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 594                              char *buf)
 595 {
 596         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 597         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 598         size_t len;
 599
 600         len = snprintf(buf, PAGE_SIZE, "mei:%s:" MEI_CL_UUID_FMT ":",
 601                 cldev->name, MEI_CL_UUID_ARGS(uuid->b));
 602
 603         return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 604 }
 605 static DEVICE_ATTR_RO(modalias);
 606
 607 static struct attribute *mei_cl_dev_attrs[] = {
 608         &dev_attr_name.attr,
 609         &dev_attr_uuid.attr,
 610         &dev_attr_modalias.attr,
 611         NULL,
 612 };
 613 ATTRIBUTE_GROUPS(mei_cl_dev);
 614
 615 /**
 616  * mei_cl_device_uevent - me client bus uevent handler
 617  *
 618  * @dev: device
 619  * @env: uevent kobject
 620  *
 621  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 622  */
 623 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 624 {
 625         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 626         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 627
 628         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 629                 return -ENOMEM;
 630
 631         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 632                 return -ENOMEM;
 633
 634         if (add_uevent_var(env, "MODALIAS=mei:%s:" MEI_CL_UUID_FMT ":",
 635                 cldev->name, MEI_CL_UUID_ARGS(uuid->b)))
 636                 return -ENOMEM;
 637
 638         return 0;
 639 }
 640
 641 static struct bus_type mei_cl_bus_type = {
 642         .name           = "mei",
 643         .dev_groups     = mei_cl_dev_groups,
 644         .match          = mei_cl_device_match,
 645         .probe          = mei_cl_device_probe,
 646         .remove         = mei_cl_device_remove,
 647         .uevent         = mei_cl_device_uevent,
 648 };
 649
 650 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 651 {
 652         if (bus)
 653                 get_device(bus->dev);
 654
 655         return bus;
 656 }
 657
 658 static void mei_dev_bus_put(struct mei_device *bus)
 659 {
 660         if (bus)
 661                 put_device(bus->dev);
 662 }
 663
 664 static void mei_cl_dev_release(struct device *dev)
 665 {
 666         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 667
 668         if (!cldev)
 669                 return;
 670
 671         mei_me_cl_put(cldev->me_cl);
 672         mei_dev_bus_put(cldev->bus);
 673         kfree(cldev);
 674 }
 675
 676 static struct device_type mei_cl_device_type = {
 677         .release        = mei_cl_dev_release,
 678 };
 679
 680 /**
 681  * mei_cl_dev_alloc - initialize and allocate mei client device
 682  *
 683  * @bus: mei device
 684  * @me_cl: me client
 685  *
 686  * Return: allocated device structur or NULL on allocation failure
 687  */
 688 static struct mei_cl_device *mei_cl_dev_alloc(struct mei_device *bus,
 689                                               struct mei_me_client *me_cl)
 690 {
 691         struct mei_cl_device *cldev;
 692
 693         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 694         if (!cldev)
 695                 return NULL;
 696
 697         device_initialize(&cldev->dev);
 698         cldev->dev.parent = bus->dev;
 699         cldev->dev.bus    = &mei_cl_bus_type;
 700         cldev->dev.type   = &mei_cl_device_type;
 701         cldev->bus        = mei_dev_bus_get(bus);
 702         cldev->me_cl      = mei_me_cl_get(me_cl);
 703         cldev->is_added   = 0;
 704         INIT_LIST_HEAD(&cldev->bus_list);
 705
 706         return cldev;
 707 }
 708
 709 /**
 710  * mei_cl_dev_setup - setup me client device
 711  *    run fix up routines and set the device name
 712  *
 713  * @bus: mei device
 714  * @cldev: me client device
 715  *
 716  * Return: true if the device is eligible for enumeration
 717  */
 718 static bool mei_cl_dev_setup(struct mei_device *bus,
 719                              struct mei_cl_device *cldev)
 720 {
 721         cldev->do_match = 1;
 722         mei_cl_dev_fixup(cldev);
 723
 724         if (cldev->do_match)
 725                 dev_set_name(&cldev->dev, "mei:%s:%pUl",
 726                              cldev->name, mei_me_cl_uuid(cldev->me_cl));
 727
 728         return cldev->do_match == 1;
 729 }
 730
 731 /**
 732  * mei_cl_bus_dev_add - add me client devices
 733  *
 734  * @cldev: me client device
 735  *
 736  * Return: 0 on success; < 0 on failre
 737  */
 738 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 739 {
 740         int ret;
 741
 742         dev_dbg(cldev->bus->dev, "adding %pUL\n", mei_me_cl_uuid(cldev->me_cl));
 743         ret = device_add(&cldev->dev);
 744         if (!ret)
 745                 cldev->is_added = 1;
 746
 747         return ret;
 748 }
 749
 750 /**
 751  * mei_cl_bus_dev_stop - stop the driver
 752  *
 753  * @cldev: me client device
 754  */
 755 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
 756 {
 757         if (cldev->is_added)
 758                 device_release_driver(&cldev->dev);
 759 }
 760
 761 /**
 762  * mei_cl_bus_dev_destroy - destroy me client devices object
 763  *
 764  * @cldev: me client device
 765  */
 766 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
 767 {
 768         if (!cldev->is_added)
 769                 return;
 770
 771         device_del(&cldev->dev);
 772
 773         mutex_lock(&cldev->bus->cl_bus_lock);
 774         list_del_init(&cldev->bus_list);
 775         mutex_unlock(&cldev->bus->cl_bus_lock);
 776
 777         cldev->is_added = 0;
 778         put_device(&cldev->dev);
 779 }
 780
 781 /**
 782  * mei_cl_bus_remove_device - remove a devices form the bus
 783  *
 784  * @cldev: me client device
 785  */
 786 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
 787 {
 788         mei_cl_bus_dev_stop(cldev);
 789         mei_cl_bus_dev_destroy(cldev);
 790 }
 791
 792 /**
 793  * mei_cl_bus_remove_devices - remove all devices form the bus
 794  *
 795  * @bus: mei device
 796  */
 797 void mei_cl_bus_remove_devices(struct mei_device *bus)
 798 {
 799         struct mei_cl_device *cldev, *next;
 800
 801         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
 802                 mei_cl_bus_remove_device(cldev);
 803 }
 804
 805
 806 /**
 807  * mei_cl_dev_init - allocate and initializes an mei client devices
 808  *     based on me client
 809  *
 810  * @bus: mei device
 811  * @me_cl: me client
 812  */
 813 static void mei_cl_dev_init(struct mei_device *bus, struct mei_me_client *me_cl)
 814 {
 815         struct mei_cl_device *cldev;
 816
 817         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
 818
 819         if (me_cl->bus_added)
 820                 return;
 821
 822         cldev = mei_cl_dev_alloc(bus, me_cl);
 823         if (!cldev)
 824                 return;
 825
 826         mutex_lock(&cldev->bus->cl_bus_lock);
 827         me_cl->bus_added = true;
 828         list_add_tail(&cldev->bus_list, &bus->device_list);
 829         mutex_unlock(&cldev->bus->cl_bus_lock);
 830
 831 }
 832
 833 /**
 834  * mei_cl_bus_rescan - scan me clients list and add create
 835  *    devices for eligible clients
 836  *
 837  * @bus: mei device
 838  */
 839 void mei_cl_bus_rescan(struct mei_device *bus)
 840 {
 841         struct mei_cl_device *cldev, *n;
 842         struct mei_me_client *me_cl;
 843
 844         down_read(&bus->me_clients_rwsem);
 845         list_for_each_entry(me_cl, &bus->me_clients, list)
 846                 mei_cl_dev_init(bus, me_cl);
 847         up_read(&bus->me_clients_rwsem);
 848
 849         mutex_lock(&bus->cl_bus_lock);
 850         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
 851
 852                 if (!mei_me_cl_is_active(cldev->me_cl)) {
 853                         mei_cl_bus_remove_device(cldev);
 854                         continue;
 855                 }
 856
 857                 if (cldev->is_added)
 858                         continue;
 859
 860                 if (mei_cl_dev_setup(bus, cldev))
 861                         mei_cl_bus_dev_add(cldev);
 862                 else {
 863                         list_del_init(&cldev->bus_list);
 864                         put_device(&cldev->dev);
 865                 }
 866         }
 867         mutex_unlock(&bus->cl_bus_lock);
 868
 869         dev_dbg(bus->dev, "rescan end");
 870 }
 871
 872 int __mei_cl_driver_register(struct mei_cl_driver *cldrv, struct module *owner)
 873 {
 874         int err;
 875
 876         cldrv->driver.name = cldrv->name;
 877         cldrv->driver.owner = owner;
 878         cldrv->driver.bus = &mei_cl_bus_type;
 879
 880         err = driver_register(&cldrv->driver);
 881         if (err)
 882                 return err;
 883
 884         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
 885
 886         return 0;
 887 }
 888 EXPORT_SYMBOL_GPL(__mei_cl_driver_register);
 889
 890 void mei_cl_driver_unregister(struct mei_cl_driver *cldrv)
 891 {
 892         driver_unregister(&cldrv->driver);
 893
 894         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
 895 }
 896 EXPORT_SYMBOL_GPL(mei_cl_driver_unregister);
 897
 898
 899 int __init mei_cl_bus_init(void)
 900 {
 901         return bus_register(&mei_cl_bus_type);
 902 }
 903
 904 void __exit mei_cl_bus_exit(void)
 905 {
 906         bus_unregister(&mei_cl_bus_type);
 907 }