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         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
  78         if (!cb) {
  79                 rets = -ENOMEM;
  80                 goto out;
  81         }
  82
  83         cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
  84         cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
  85         memcpy(cb->buf.data, buf, length);
  86
  87         rets = mei_cl_write(cl, cb);
  88
  89 out:
  90         mutex_unlock(&bus->device_lock);
  91
  92         return rets;
  93 }
  94
  95 /**
  96  * __mei_cl_recv - internal client receive (read)
  97  *
  98  * @cl: host client
  99  * @buf: buffer to receive
 100  * @length: buffer length
 101  * @mode: io mode
 102  *
 103  * Return: read size in bytes of < 0 on error
 104  */
 105 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
 106                       unsigned int mode)
 107 {
 108         struct mei_device *bus;
 109         struct mei_cl_cb *cb;
 110         size_t r_length;
 111         ssize_t rets;
 112         bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
 113
 114         if (WARN_ON(!cl || !cl->dev))
 115                 return -ENODEV;
 116
 117         bus = cl->dev;
 118
 119         mutex_lock(&bus->device_lock);
 120         if (bus->dev_state != MEI_DEV_ENABLED) {
 121                 rets = -ENODEV;
 122                 goto out;
 123         }
 124
 125         cb = mei_cl_read_cb(cl, NULL);
 126         if (cb)
 127                 goto copy;
 128
 129         rets = mei_cl_read_start(cl, length, NULL);
 130         if (rets && rets != -EBUSY)
 131                 goto out;
 132
 133         if (nonblock) {
 134                 rets = -EAGAIN;
 135                 goto out;
 136         }
 137
 138         /* wait on event only if there is no other waiter */
 139         /* synchronized under device mutex */
 140         if (!waitqueue_active(&cl->rx_wait)) {
 141
 142                 mutex_unlock(&bus->device_lock);
 143
 144                 if (wait_event_interruptible(cl->rx_wait,
 145                                 (!list_empty(&cl->rd_completed)) ||
 146                                 (!mei_cl_is_connected(cl)))) {
 147
 148                         if (signal_pending(current))
 149                                 return -EINTR;
 150                         return -ERESTARTSYS;
 151                 }
 152
 153                 mutex_lock(&bus->device_lock);
 154
 155                 if (!mei_cl_is_connected(cl)) {
 156                         rets = -ENODEV;
 157                         goto out;
 158                 }
 159         }
 160
 161         cb = mei_cl_read_cb(cl, NULL);
 162         if (!cb) {
 163                 rets = 0;
 164                 goto out;
 165         }
 166
 167 copy:
 168         if (cb->status) {
 169                 rets = cb->status;
 170                 goto free;
 171         }
 172
 173         r_length = min_t(size_t, length, cb->buf_idx);
 174         memcpy(buf, cb->buf.data, r_length);
 175         rets = r_length;
 176
 177 free:
 178         mei_io_cb_free(cb);
 179 out:
 180         mutex_unlock(&bus->device_lock);
 181
 182         return rets;
 183 }
 184
 185 /**
 186  * mei_cldev_send - me device send  (write)
 187  *
 188  * @cldev: me client device
 189  * @buf: buffer to send
 190  * @length: buffer length
 191  *
 192  * Return: written size in bytes or < 0 on error
 193  */
 194 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
 195 {
 196         struct mei_cl *cl = cldev->cl;
 197
 198         return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
 199 }
 200 EXPORT_SYMBOL_GPL(mei_cldev_send);
 201
 202 /**
 203  * mei_cldev_recv_nonblock - non block client receive (read)
 204  *
 205  * @cldev: me client device
 206  * @buf: buffer to receive
 207  * @length: buffer length
 208  *
 209  * Return: read size in bytes of < 0 on error
 210  *         -EAGAIN if function will block.
 211  */
 212 ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
 213                                 size_t length)
 214 {
 215         struct mei_cl *cl = cldev->cl;
 216
 217         return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK);
 218 }
 219 EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
 220
 221 /**
 222  * mei_cldev_recv - client receive (read)
 223  *
 224  * @cldev: me client device
 225  * @buf: buffer to receive
 226  * @length: buffer length
 227  *
 228  * Return: read size in bytes of < 0 on error
 229  */
 230 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 231 {
 232         struct mei_cl *cl = cldev->cl;
 233
 234         return __mei_cl_recv(cl, buf, length, 0);
 235 }
 236 EXPORT_SYMBOL_GPL(mei_cldev_recv);
 237
 238 /**
 239  * mei_cl_bus_rx_work - dispatch rx event for a bus device
 240  *
 241  * @work: work
 242  */
 243 static void mei_cl_bus_rx_work(struct work_struct *work)
 244 {
 245         struct mei_cl_device *cldev;
 246         struct mei_device *bus;
 247
 248         cldev = container_of(work, struct mei_cl_device, rx_work);
 249
 250         bus = cldev->bus;
 251
 252         if (cldev->rx_cb)
 253                 cldev->rx_cb(cldev);
 254
 255         mutex_lock(&bus->device_lock);
 256         mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 257         mutex_unlock(&bus->device_lock);
 258 }
 259
 260 /**
 261  * mei_cl_bus_notif_work - dispatch FW notif event for a bus device
 262  *
 263  * @work: work
 264  */
 265 static void mei_cl_bus_notif_work(struct work_struct *work)
 266 {
 267         struct mei_cl_device *cldev;
 268
 269         cldev = container_of(work, struct mei_cl_device, notif_work);
 270
 271         if (cldev->notif_cb)
 272                 cldev->notif_cb(cldev);
 273 }
 274
 275 /**
 276  * mei_cl_bus_notify_event - schedule notify cb on bus client
 277  *
 278  * @cl: host client
 279  *
 280  * Return: true if event was scheduled
 281  *         false if the client is not waiting for event
 282  */
 283 bool mei_cl_bus_notify_event(struct mei_cl *cl)
 284 {
 285         struct mei_cl_device *cldev = cl->cldev;
 286
 287         if (!cldev || !cldev->notif_cb)
 288                 return false;
 289
 290         if (!cl->notify_ev)
 291                 return false;
 292
 293         schedule_work(&cldev->notif_work);
 294
 295         cl->notify_ev = false;
 296
 297         return true;
 298 }
 299
 300 /**
 301  * mei_cl_bus_rx_event - schedule rx event
 302  *
 303  * @cl: host client
 304  *
 305  * Return: true if event was scheduled
 306  *         false if the client is not waiting for event
 307  */
 308 bool mei_cl_bus_rx_event(struct mei_cl *cl)
 309 {
 310         struct mei_cl_device *cldev = cl->cldev;
 311
 312         if (!cldev || !cldev->rx_cb)
 313                 return false;
 314
 315         schedule_work(&cldev->rx_work);
 316
 317         return true;
 318 }
 319
 320 /**
 321  * mei_cldev_register_rx_cb - register Rx event callback
 322  *
 323  * @cldev: me client devices
 324  * @rx_cb: callback function
 325  *
 326  * Return: 0 on success
 327  *         -EALREADY if an callback is already registered
 328  *         <0 on other errors
 329  */
 330 int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
 331 {
 332         struct mei_device *bus = cldev->bus;
 333         int ret;
 334
 335         if (!rx_cb)
 336                 return -EINVAL;
 337         if (cldev->rx_cb)
 338                 return -EALREADY;
 339
 340         cldev->rx_cb = rx_cb;
 341         INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
 342
 343         mutex_lock(&bus->device_lock);
 344         ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 345         mutex_unlock(&bus->device_lock);
 346         if (ret && ret != -EBUSY)
 347                 return ret;
 348
 349         return 0;
 350 }
 351 EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
 352
 353 /**
 354  * mei_cldev_register_notif_cb - register FW notification event callback
 355  *
 356  * @cldev: me client devices
 357  * @notif_cb: callback function
 358  *
 359  * Return: 0 on success
 360  *         -EALREADY if an callback is already registered
 361  *         <0 on other errors
 362  */
 363 int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
 364                                 mei_cldev_cb_t notif_cb)
 365 {
 366         struct mei_device *bus = cldev->bus;
 367         int ret;
 368
 369         if (!notif_cb)
 370                 return -EINVAL;
 371
 372         if (cldev->notif_cb)
 373                 return -EALREADY;
 374
 375         cldev->notif_cb = notif_cb;
 376         INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
 377
 378         mutex_lock(&bus->device_lock);
 379         ret = mei_cl_notify_request(cldev->cl, NULL, 1);
 380         mutex_unlock(&bus->device_lock);
 381         if (ret)
 382                 return ret;
 383
 384         return 0;
 385 }
 386 EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
 387
 388 /**
 389  * mei_cldev_get_drvdata - driver data getter
 390  *
 391  * @cldev: mei client device
 392  *
 393  * Return: driver private data
 394  */
 395 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
 396 {
 397         return dev_get_drvdata(&cldev->dev);
 398 }
 399 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
 400
 401 /**
 402  * mei_cldev_set_drvdata - driver data setter
 403  *
 404  * @cldev: mei client device
 405  * @data: data to store
 406  */
 407 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
 408 {
 409         dev_set_drvdata(&cldev->dev, data);
 410 }
 411 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
 412
 413 /**
 414  * mei_cldev_uuid - return uuid of the underlying me client
 415  *
 416  * @cldev: mei client device
 417  *
 418  * Return: me client uuid
 419  */
 420 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
 421 {
 422         return mei_me_cl_uuid(cldev->me_cl);
 423 }
 424 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
 425
 426 /**
 427  * mei_cldev_ver - return protocol version of the underlying me client
 428  *
 429  * @cldev: mei client device
 430  *
 431  * Return: me client protocol version
 432  */
 433 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
 434 {
 435         return mei_me_cl_ver(cldev->me_cl);
 436 }
 437 EXPORT_SYMBOL_GPL(mei_cldev_ver);
 438
 439 /**
 440  * mei_cldev_enabled - check whether the device is enabled
 441  *
 442  * @cldev: mei client device
 443  *
 444  * Return: true if me client is initialized and connected
 445  */
 446 bool mei_cldev_enabled(struct mei_cl_device *cldev)
 447 {
 448         return mei_cl_is_connected(cldev->cl);
 449 }
 450 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
 451
 452 /**
 453  * mei_cldev_enable - enable me client device
 454  *     create connection with me client
 455  *
 456  * @cldev: me client device
 457  *
 458  * Return: 0 on success and < 0 on error
 459  */
 460 int mei_cldev_enable(struct mei_cl_device *cldev)
 461 {
 462         struct mei_device *bus = cldev->bus;
 463         struct mei_cl *cl;
 464         int ret;
 465
 466         cl = cldev->cl;
 467
 468         if (cl->state == MEI_FILE_UNINITIALIZED) {
 469                 mutex_lock(&bus->device_lock);
 470                 ret = mei_cl_link(cl);
 471                 mutex_unlock(&bus->device_lock);
 472                 if (ret)
 473                         return ret;
 474                 /* update pointers */
 475                 cl->cldev = cldev;
 476         }
 477
 478         mutex_lock(&bus->device_lock);
 479         if (mei_cl_is_connected(cl)) {
 480                 ret = 0;
 481                 goto out;
 482         }
 483
 484         if (!mei_me_cl_is_active(cldev->me_cl)) {
 485                 dev_err(&cldev->dev, "me client is not active\n");
 486                 ret = -ENOTTY;
 487                 goto out;
 488         }
 489
 490         ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 491         if (ret < 0)
 492                 dev_err(&cldev->dev, "cannot connect\n");
 493
 494 out:
 495         mutex_unlock(&bus->device_lock);
 496
 497         return ret;
 498 }
 499 EXPORT_SYMBOL_GPL(mei_cldev_enable);
 500
 501 /**
 502  * mei_cldev_unregister_callbacks - internal wrapper for unregistering
 503  *  callbacks.
 504  *
 505  * @cldev: client device
 506  */
 507 static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
 508 {
 509         if (cldev->rx_cb) {
 510                 cancel_work_sync(&cldev->rx_work);
 511                 cldev->rx_cb = NULL;
 512         }
 513
 514         if (cldev->notif_cb) {
 515                 cancel_work_sync(&cldev->notif_work);
 516                 cldev->notif_cb = NULL;
 517         }
 518 }
 519
 520 /**
 521  * mei_cldev_disable - disable me client device
 522  *     disconnect form the me client
 523  *
 524  * @cldev: me client device
 525  *
 526  * Return: 0 on success and < 0 on error
 527  */
 528 int mei_cldev_disable(struct mei_cl_device *cldev)
 529 {
 530         struct mei_device *bus;
 531         struct mei_cl *cl;
 532         int err;
 533
 534         if (!cldev)
 535                 return -ENODEV;
 536
 537         cl = cldev->cl;
 538
 539         bus = cldev->bus;
 540
 541         mei_cldev_unregister_callbacks(cldev);
 542
 543         mutex_lock(&bus->device_lock);
 544
 545         if (!mei_cl_is_connected(cl)) {
 546                 dev_dbg(bus->dev, "Already disconnected\n");
 547                 err = 0;
 548                 goto out;
 549         }
 550
 551         if (bus->dev_state == MEI_DEV_POWER_DOWN) {
 552                 dev_dbg(bus->dev, "Device is powering down, don't bother with disconnection\n");
 553                 err = 0;
 554                 goto out;
 555         }
 556
 557         err = mei_cl_disconnect(cl);
 558         if (err < 0)
 559                 dev_err(bus->dev, "Could not disconnect from the ME client\n");
 560
 561 out:
 562         /* Flush queues and remove any pending read */
 563         mei_cl_flush_queues(cl, NULL);
 564         mei_cl_unlink(cl);
 565
 566         mutex_unlock(&bus->device_lock);
 567         return err;
 568 }
 569 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 570
 571 /**
 572  * mei_cl_bus_module_get - acquire module of the underlying
 573  *    hw module.
 574  *
 575  * @cl: host client
 576  *
 577  * Return: true on success; false if the module was removed.
 578  */
 579 bool mei_cl_bus_module_get(struct mei_cl *cl)
 580 {
 581         struct mei_cl_device *cldev = cl->cldev;
 582
 583         if (!cldev)
 584                 return true;
 585
 586         return try_module_get(cldev->bus->dev->driver->owner);
 587 }
 588
 589 /**
 590  * mei_cl_bus_module_put -  release the underlying hw module.
 591  *
 592  * @cl: host client
 593  */
 594 void mei_cl_bus_module_put(struct mei_cl *cl)
 595 {
 596         struct mei_cl_device *cldev = cl->cldev;
 597
 598         if (cldev)
 599                 module_put(cldev->bus->dev->driver->owner);
 600 }
 601
 602 /**
 603  * mei_cl_device_find - find matching entry in the driver id table
 604  *
 605  * @cldev: me client device
 606  * @cldrv: me client driver
 607  *
 608  * Return: id on success; NULL if no id is matching
 609  */
 610 static const
 611 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 612                                             struct mei_cl_driver *cldrv)
 613 {
 614         const struct mei_cl_device_id *id;
 615         const uuid_le *uuid;
 616         u8 version;
 617         bool match;
 618
 619         uuid = mei_me_cl_uuid(cldev->me_cl);
 620         version = mei_me_cl_ver(cldev->me_cl);
 621
 622         id = cldrv->id_table;
 623         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 624                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 625                         match = true;
 626
 627                         if (cldev->name[0])
 628                                 if (strncmp(cldev->name, id->name,
 629                                             sizeof(id->name)))
 630                                         match = false;
 631
 632                         if (id->version != MEI_CL_VERSION_ANY)
 633                                 if (id->version != version)
 634                                         match = false;
 635                         if (match)
 636                                 return id;
 637                 }
 638
 639                 id++;
 640         }
 641
 642         return NULL;
 643 }
 644
 645 /**
 646  * mei_cl_device_match  - device match function
 647  *
 648  * @dev: device
 649  * @drv: driver
 650  *
 651  * Return:  1 if matching device was found 0 otherwise
 652  */
 653 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 654 {
 655         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 656         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 657         const struct mei_cl_device_id *found_id;
 658
 659         if (!cldev)
 660                 return 0;
 661
 662         if (!cldev->do_match)
 663                 return 0;
 664
 665         if (!cldrv || !cldrv->id_table)
 666                 return 0;
 667
 668         found_id = mei_cl_device_find(cldev, cldrv);
 669         if (found_id)
 670                 return 1;
 671
 672         return 0;
 673 }
 674
 675 /**
 676  * mei_cl_device_probe - bus probe function
 677  *
 678  * @dev: device
 679  *
 680  * Return:  0 on success; < 0 otherwise
 681  */
 682 static int mei_cl_device_probe(struct device *dev)
 683 {
 684         struct mei_cl_device *cldev;
 685         struct mei_cl_driver *cldrv;
 686         const struct mei_cl_device_id *id;
 687         int ret;
 688
 689         cldev = to_mei_cl_device(dev);
 690         cldrv = to_mei_cl_driver(dev->driver);
 691
 692         if (!cldev)
 693                 return 0;
 694
 695         if (!cldrv || !cldrv->probe)
 696                 return -ENODEV;
 697
 698         id = mei_cl_device_find(cldev, cldrv);
 699         if (!id)
 700                 return -ENODEV;
 701
 702         ret = cldrv->probe(cldev, id);
 703         if (ret)
 704                 return ret;
 705
 706         __module_get(THIS_MODULE);
 707         return 0;
 708 }
 709
 710 /**
 711  * mei_cl_device_remove - remove device from the bus
 712  *
 713  * @dev: device
 714  *
 715  * Return:  0 on success; < 0 otherwise
 716  */
 717 static int mei_cl_device_remove(struct device *dev)
 718 {
 719         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 720         struct mei_cl_driver *cldrv;
 721         int ret = 0;
 722
 723         if (!cldev || !dev->driver)
 724                 return 0;
 725
 726         cldrv = to_mei_cl_driver(dev->driver);
 727         if (cldrv->remove)
 728                 ret = cldrv->remove(cldev);
 729
 730         mei_cldev_unregister_callbacks(cldev);
 731
 732         module_put(THIS_MODULE);
 733         dev->driver = NULL;
 734         return ret;
 735
 736 }
 737
 738 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 739                              char *buf)
 740 {
 741         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 742
 743         return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
 744 }
 745 static DEVICE_ATTR_RO(name);
 746
 747 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 748                              char *buf)
 749 {
 750         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 751         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 752
 753         return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
 754 }
 755 static DEVICE_ATTR_RO(uuid);
 756
 757 static ssize_t version_show(struct device *dev, struct device_attribute *a,
 758                              char *buf)
 759 {
 760         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 761         u8 version = mei_me_cl_ver(cldev->me_cl);
 762
 763         return scnprintf(buf, PAGE_SIZE, "%02X", version);
 764 }
 765 static DEVICE_ATTR_RO(version);
 766
 767 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 768                              char *buf)
 769 {
 770         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 771         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 772         u8 version = mei_me_cl_ver(cldev->me_cl);
 773
 774         return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
 775                          cldev->name, uuid, version);
 776 }
 777 static DEVICE_ATTR_RO(modalias);
 778
 779 static struct attribute *mei_cldev_attrs[] = {
 780         &dev_attr_name.attr,
 781         &dev_attr_uuid.attr,
 782         &dev_attr_version.attr,
 783         &dev_attr_modalias.attr,
 784         NULL,
 785 };
 786 ATTRIBUTE_GROUPS(mei_cldev);
 787
 788 /**
 789  * mei_cl_device_uevent - me client bus uevent handler
 790  *
 791  * @dev: device
 792  * @env: uevent kobject
 793  *
 794  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 795  */
 796 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 797 {
 798         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 799         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 800         u8 version = mei_me_cl_ver(cldev->me_cl);
 801
 802         if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
 803                 return -ENOMEM;
 804
 805         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 806                 return -ENOMEM;
 807
 808         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 809                 return -ENOMEM;
 810
 811         if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
 812                            cldev->name, uuid, version))
 813                 return -ENOMEM;
 814
 815         return 0;
 816 }
 817
 818 static struct bus_type mei_cl_bus_type = {
 819         .name           = "mei",
 820         .dev_groups     = mei_cldev_groups,
 821         .match          = mei_cl_device_match,
 822         .probe          = mei_cl_device_probe,
 823         .remove         = mei_cl_device_remove,
 824         .uevent         = mei_cl_device_uevent,
 825 };
 826
 827 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 828 {
 829         if (bus)
 830                 get_device(bus->dev);
 831
 832         return bus;
 833 }
 834
 835 static void mei_dev_bus_put(struct mei_device *bus)
 836 {
 837         if (bus)
 838                 put_device(bus->dev);
 839 }
 840
 841 static void mei_cl_bus_dev_release(struct device *dev)
 842 {
 843         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 844
 845         if (!cldev)
 846                 return;
 847
 848         mei_me_cl_put(cldev->me_cl);
 849         mei_dev_bus_put(cldev->bus);
 850         kfree(cldev->cl);
 851         kfree(cldev);
 852 }
 853
 854 static const struct device_type mei_cl_device_type = {
 855         .release        = mei_cl_bus_dev_release,
 856 };
 857
 858 /**
 859  * mei_cl_bus_set_name - set device name for me client device
 860  *
 861  * @cldev: me client device
 862  */
 863 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
 864 {
 865         dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
 866                      cldev->name,
 867                      mei_me_cl_uuid(cldev->me_cl),
 868                      mei_me_cl_ver(cldev->me_cl));
 869 }
 870
 871 /**
 872  * mei_cl_bus_dev_alloc - initialize and allocate mei client device
 873  *
 874  * @bus: mei device
 875  * @me_cl: me client
 876  *
 877  * Return: allocated device structur or NULL on allocation failure
 878  */
 879 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 880                                                   struct mei_me_client *me_cl)
 881 {
 882         struct mei_cl_device *cldev;
 883         struct mei_cl *cl;
 884
 885         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 886         if (!cldev)
 887                 return NULL;
 888
 889         cl = mei_cl_allocate(bus);
 890         if (!cl) {
 891                 kfree(cldev);
 892                 return NULL;
 893         }
 894
 895         device_initialize(&cldev->dev);
 896         cldev->dev.parent = bus->dev;
 897         cldev->dev.bus    = &mei_cl_bus_type;
 898         cldev->dev.type   = &mei_cl_device_type;
 899         cldev->bus        = mei_dev_bus_get(bus);
 900         cldev->me_cl      = mei_me_cl_get(me_cl);
 901         cldev->cl         = cl;
 902         mei_cl_bus_set_name(cldev);
 903         cldev->is_added   = 0;
 904         INIT_LIST_HEAD(&cldev->bus_list);
 905
 906         return cldev;
 907 }
 908
 909 /**
 910  * mei_cl_dev_setup - setup me client device
 911  *    run fix up routines and set the device name
 912  *
 913  * @bus: mei device
 914  * @cldev: me client device
 915  *
 916  * Return: true if the device is eligible for enumeration
 917  */
 918 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
 919                                  struct mei_cl_device *cldev)
 920 {
 921         cldev->do_match = 1;
 922         mei_cl_bus_dev_fixup(cldev);
 923
 924         /* the device name can change during fix up */
 925         if (cldev->do_match)
 926                 mei_cl_bus_set_name(cldev);
 927
 928         return cldev->do_match == 1;
 929 }
 930
 931 /**
 932  * mei_cl_bus_dev_add - add me client devices
 933  *
 934  * @cldev: me client device
 935  *
 936  * Return: 0 on success; < 0 on failre
 937  */
 938 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 939 {
 940         int ret;
 941
 942         dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
 943                 mei_me_cl_uuid(cldev->me_cl),
 944                 mei_me_cl_ver(cldev->me_cl));
 945         ret = device_add(&cldev->dev);
 946         if (!ret)
 947                 cldev->is_added = 1;
 948
 949         return ret;
 950 }
 951
 952 /**
 953  * mei_cl_bus_dev_stop - stop the driver
 954  *
 955  * @cldev: me client device
 956  */
 957 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
 958 {
 959         if (cldev->is_added)
 960                 device_release_driver(&cldev->dev);
 961 }
 962
 963 /**
 964  * mei_cl_bus_dev_destroy - destroy me client devices object
 965  *
 966  * @cldev: me client device
 967  *
 968  * Locking: called under "dev->cl_bus_lock" lock
 969  */
 970 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
 971 {
 972
 973         WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
 974
 975         if (!cldev->is_added)
 976                 return;
 977
 978         device_del(&cldev->dev);
 979
 980         list_del_init(&cldev->bus_list);
 981
 982         cldev->is_added = 0;
 983         put_device(&cldev->dev);
 984 }
 985
 986 /**
 987  * mei_cl_bus_remove_device - remove a devices form the bus
 988  *
 989  * @cldev: me client device
 990  */
 991 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
 992 {
 993         mei_cl_bus_dev_stop(cldev);
 994         mei_cl_bus_dev_destroy(cldev);
 995 }
 996
 997 /**
 998  * mei_cl_bus_remove_devices - remove all devices form the bus
 999  *
1000  * @bus: mei device
1001  */
1002 void mei_cl_bus_remove_devices(struct mei_device *bus)
1003 {
1004         struct mei_cl_device *cldev, *next;
1005
1006         mutex_lock(&bus->cl_bus_lock);
1007         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1008                 mei_cl_bus_remove_device(cldev);
1009         mutex_unlock(&bus->cl_bus_lock);
1010 }
1011
1012
1013 /**
1014  * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1015  *     based on me client
1016  *
1017  * @bus: mei device
1018  * @me_cl: me client
1019  *
1020  * Locking: called under "dev->cl_bus_lock" lock
1021  */
1022 static void mei_cl_bus_dev_init(struct mei_device *bus,
1023                                 struct mei_me_client *me_cl)
1024 {
1025         struct mei_cl_device *cldev;
1026
1027         WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1028
1029         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1030
1031         if (me_cl->bus_added)
1032                 return;
1033
1034         cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1035         if (!cldev)
1036                 return;
1037
1038         me_cl->bus_added = true;
1039         list_add_tail(&cldev->bus_list, &bus->device_list);
1040
1041 }
1042
1043 /**
1044  * mei_cl_bus_rescan - scan me clients list and add create
1045  *    devices for eligible clients
1046  *
1047  * @bus: mei device
1048  */
1049 static void mei_cl_bus_rescan(struct mei_device *bus)
1050 {
1051         struct mei_cl_device *cldev, *n;
1052         struct mei_me_client *me_cl;
1053
1054         mutex_lock(&bus->cl_bus_lock);
1055
1056         down_read(&bus->me_clients_rwsem);
1057         list_for_each_entry(me_cl, &bus->me_clients, list)
1058                 mei_cl_bus_dev_init(bus, me_cl);
1059         up_read(&bus->me_clients_rwsem);
1060
1061         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1062
1063                 if (!mei_me_cl_is_active(cldev->me_cl)) {
1064                         mei_cl_bus_remove_device(cldev);
1065                         continue;
1066                 }
1067
1068                 if (cldev->is_added)
1069                         continue;
1070
1071                 if (mei_cl_bus_dev_setup(bus, cldev))
1072                         mei_cl_bus_dev_add(cldev);
1073                 else {
1074                         list_del_init(&cldev->bus_list);
1075                         put_device(&cldev->dev);
1076                 }
1077         }
1078         mutex_unlock(&bus->cl_bus_lock);
1079
1080         dev_dbg(bus->dev, "rescan end");
1081 }
1082
1083 void mei_cl_bus_rescan_work(struct work_struct *work)
1084 {
1085         struct mei_device *bus =
1086                 container_of(work, struct mei_device, bus_rescan_work);
1087
1088         mei_cl_bus_rescan(bus);
1089 }
1090
1091 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1092                                 struct module *owner)
1093 {
1094         int err;
1095
1096         cldrv->driver.name = cldrv->name;
1097         cldrv->driver.owner = owner;
1098         cldrv->driver.bus = &mei_cl_bus_type;
1099
1100         err = driver_register(&cldrv->driver);
1101         if (err)
1102                 return err;
1103
1104         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1105
1106         return 0;
1107 }
1108 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1109
1110 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1111 {
1112         driver_unregister(&cldrv->driver);
1113
1114         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1115 }
1116 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1117
1118
1119 int __init mei_cl_bus_init(void)
1120 {
1121         return bus_register(&mei_cl_bus_type);
1122 }
1123
1124 void __exit mei_cl_bus_exit(void)
1125 {
1126         bus_unregister(&mei_cl_bus_type);
1127 }