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