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