drivers/misc/mei/bus.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
   4  * Intel Management Engine Interface (Intel MEI) Linux driver
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/device.h>
   9 #include <linux/kernel.h>
  10 #include <linux/sched/signal.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <linux/slab.h>
  14 #include <linux/mutex.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/mei_cl_bus.h>
  17
  18 #include "mei_dev.h"
  19 #include "client.h"
  20
  21 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
  22
  23 /**
  24  * __mei_cl_send - internal client send (write)
  25  *
  26  * @cl: host client
  27  * @buf: buffer to send
  28  * @length: buffer length
  29  * @mode: sending mode
  30  *
  31  * Return: written size bytes or < 0 on error
  32  */
  33 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
  34                       unsigned int mode)
  35 {
  36         struct mei_device *bus;
  37         struct mei_cl_cb *cb;
  38         ssize_t rets;
  39
  40         if (WARN_ON(!cl || !cl->dev))
  41                 return -ENODEV;
  42
  43         bus = cl->dev;
  44
  45         mutex_lock(&bus->device_lock);
  46         if (bus->dev_state != MEI_DEV_ENABLED) {
  47                 rets = -ENODEV;
  48                 goto out;
  49         }
  50
  51         if (!mei_cl_is_connected(cl)) {
  52                 rets = -ENODEV;
  53                 goto out;
  54         }
  55
  56         /* Check if we have an ME client device */
  57         if (!mei_me_cl_is_active(cl->me_cl)) {
  58                 rets = -ENOTTY;
  59                 goto out;
  60         }
  61
  62         if (length > mei_cl_mtu(cl)) {
  63                 rets = -EFBIG;
  64                 goto out;
  65         }
  66
  67         while (cl->tx_cb_queued >= bus->tx_queue_limit) {
  68                 mutex_unlock(&bus->device_lock);
  69                 rets = wait_event_interruptible(cl->tx_wait,
  70                                 cl->writing_state == MEI_WRITE_COMPLETE ||
  71                                 (!mei_cl_is_connected(cl)));
  72                 mutex_lock(&bus->device_lock);
  73                 if (rets) {
  74                         if (signal_pending(current))
  75                                 rets = -EINTR;
  76                         goto out;
  77                 }
  78                 if (!mei_cl_is_connected(cl)) {
  79                         rets = -ENODEV;
  80                         goto out;
  81                 }
  82         }
  83
  84         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
  85         if (!cb) {
  86                 rets = -ENOMEM;
  87                 goto out;
  88         }
  89
  90         cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
  91         cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
  92         memcpy(cb->buf.data, buf, length);
  93
  94         rets = mei_cl_write(cl, cb);
  95
  96 out:
  97         mutex_unlock(&bus->device_lock);
  98
  99         return rets;
 100 }
 101
 102 /**
 103  * __mei_cl_recv - internal client receive (read)
 104  *
 105  * @cl: host client
 106  * @buf: buffer to receive
 107  * @length: buffer length
 108  * @mode: io mode
 109  * @timeout: recv timeout, 0 for infinite timeout
 110  *
 111  * Return: read size in bytes of < 0 on error
 112  */
 113 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
 114                       unsigned int mode, unsigned long timeout)
 115 {
 116         struct mei_device *bus;
 117         struct mei_cl_cb *cb;
 118         size_t r_length;
 119         ssize_t rets;
 120         bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
 121
 122         if (WARN_ON(!cl || !cl->dev))
 123                 return -ENODEV;
 124
 125         bus = cl->dev;
 126
 127         mutex_lock(&bus->device_lock);
 128         if (bus->dev_state != MEI_DEV_ENABLED) {
 129                 rets = -ENODEV;
 130                 goto out;
 131         }
 132
 133         cb = mei_cl_read_cb(cl, NULL);
 134         if (cb)
 135                 goto copy;
 136
 137         rets = mei_cl_read_start(cl, length, NULL);
 138         if (rets && rets != -EBUSY)
 139                 goto out;
 140
 141         if (nonblock) {
 142                 rets = -EAGAIN;
 143                 goto out;
 144         }
 145
 146         /* wait on event only if there is no other waiter */
 147         /* synchronized under device mutex */
 148         if (!waitqueue_active(&cl->rx_wait)) {
 149
 150                 mutex_unlock(&bus->device_lock);
 151
 152                 if (timeout) {
 153                         rets = wait_event_interruptible_timeout
 154                                         (cl->rx_wait,
 155                                         (!list_empty(&cl->rd_completed)) ||
 156                                         (!mei_cl_is_connected(cl)),
 157                                         msecs_to_jiffies(timeout));
 158                         if (rets == 0)
 159                                 return -ETIME;
 160                         if (rets < 0) {
 161                                 if (signal_pending(current))
 162                                         return -EINTR;
 163                                 return -ERESTARTSYS;
 164                         }
 165                 } else {
 166                         if (wait_event_interruptible
 167                                         (cl->rx_wait,
 168                                         (!list_empty(&cl->rd_completed)) ||
 169                                         (!mei_cl_is_connected(cl)))) {
 170                                 if (signal_pending(current))
 171                                         return -EINTR;
 172                                 return -ERESTARTSYS;
 173                         }
 174                 }
 175
 176                 mutex_lock(&bus->device_lock);
 177
 178                 if (!mei_cl_is_connected(cl)) {
 179                         rets = -ENODEV;
 180                         goto out;
 181                 }
 182         }
 183
 184         cb = mei_cl_read_cb(cl, NULL);
 185         if (!cb) {
 186                 rets = 0;
 187                 goto out;
 188         }
 189
 190 copy:
 191         if (cb->status) {
 192                 rets = cb->status;
 193                 goto free;
 194         }
 195
 196         r_length = min_t(size_t, length, cb->buf_idx);
 197         memcpy(buf, cb->buf.data, r_length);
 198         rets = r_length;
 199
 200 free:
 201         mei_io_cb_free(cb);
 202 out:
 203         mutex_unlock(&bus->device_lock);
 204
 205         return rets;
 206 }
 207
 208 /**
 209  * mei_cldev_send - me device send  (write)
 210  *
 211  * @cldev: me client device
 212  * @buf: buffer to send
 213  * @length: buffer length
 214  *
 215  * Return: written size in bytes or < 0 on error
 216  */
 217 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
 218 {
 219         struct mei_cl *cl = cldev->cl;
 220
 221         return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
 222 }
 223 EXPORT_SYMBOL_GPL(mei_cldev_send);
 224
 225 /**
 226  * mei_cldev_recv_nonblock - non block client receive (read)
 227  *
 228  * @cldev: me client device
 229  * @buf: buffer to receive
 230  * @length: buffer length
 231  *
 232  * Return: read size in bytes of < 0 on error
 233  *         -EAGAIN if function will block.
 234  */
 235 ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
 236                                 size_t length)
 237 {
 238         struct mei_cl *cl = cldev->cl;
 239
 240         return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
 241 }
 242 EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
 243
 244 /**
 245  * mei_cldev_recv - client receive (read)
 246  *
 247  * @cldev: me client device
 248  * @buf: buffer to receive
 249  * @length: buffer length
 250  *
 251  * Return: read size in bytes of < 0 on error
 252  */
 253 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 254 {
 255         struct mei_cl *cl = cldev->cl;
 256
 257         return __mei_cl_recv(cl, buf, length, 0, 0);
 258 }
 259 EXPORT_SYMBOL_GPL(mei_cldev_recv);
 260
 261 /**
 262  * mei_cl_bus_rx_work - dispatch rx event for a bus device
 263  *
 264  * @work: work
 265  */
 266 static void mei_cl_bus_rx_work(struct work_struct *work)
 267 {
 268         struct mei_cl_device *cldev;
 269         struct mei_device *bus;
 270
 271         cldev = container_of(work, struct mei_cl_device, rx_work);
 272
 273         bus = cldev->bus;
 274
 275         if (cldev->rx_cb)
 276                 cldev->rx_cb(cldev);
 277
 278         mutex_lock(&bus->device_lock);
 279         mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 280         mutex_unlock(&bus->device_lock);
 281 }
 282
 283 /**
 284  * mei_cl_bus_notif_work - dispatch FW notif event for a bus device
 285  *
 286  * @work: work
 287  */
 288 static void mei_cl_bus_notif_work(struct work_struct *work)
 289 {
 290         struct mei_cl_device *cldev;
 291
 292         cldev = container_of(work, struct mei_cl_device, notif_work);
 293
 294         if (cldev->notif_cb)
 295                 cldev->notif_cb(cldev);
 296 }
 297
 298 /**
 299  * mei_cl_bus_notify_event - schedule notify cb on bus client
 300  *
 301  * @cl: host client
 302  *
 303  * Return: true if event was scheduled
 304  *         false if the client is not waiting for event
 305  */
 306 bool mei_cl_bus_notify_event(struct mei_cl *cl)
 307 {
 308         struct mei_cl_device *cldev = cl->cldev;
 309
 310         if (!cldev || !cldev->notif_cb)
 311                 return false;
 312
 313         if (!cl->notify_ev)
 314                 return false;
 315
 316         schedule_work(&cldev->notif_work);
 317
 318         cl->notify_ev = false;
 319
 320         return true;
 321 }
 322
 323 /**
 324  * mei_cl_bus_rx_event - schedule rx event
 325  *
 326  * @cl: host client
 327  *
 328  * Return: true if event was scheduled
 329  *         false if the client is not waiting for event
 330  */
 331 bool mei_cl_bus_rx_event(struct mei_cl *cl)
 332 {
 333         struct mei_cl_device *cldev = cl->cldev;
 334
 335         if (!cldev || !cldev->rx_cb)
 336                 return false;
 337
 338         schedule_work(&cldev->rx_work);
 339
 340         return true;
 341 }
 342
 343 /**
 344  * mei_cldev_register_rx_cb - register Rx event callback
 345  *
 346  * @cldev: me client devices
 347  * @rx_cb: callback function
 348  *
 349  * Return: 0 on success
 350  *         -EALREADY if an callback is already registered
 351  *         <0 on other errors
 352  */
 353 int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
 354 {
 355         struct mei_device *bus = cldev->bus;
 356         int ret;
 357
 358         if (!rx_cb)
 359                 return -EINVAL;
 360         if (cldev->rx_cb)
 361                 return -EALREADY;
 362
 363         cldev->rx_cb = rx_cb;
 364         INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
 365
 366         mutex_lock(&bus->device_lock);
 367         ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 368         mutex_unlock(&bus->device_lock);
 369         if (ret && ret != -EBUSY)
 370                 return ret;
 371
 372         return 0;
 373 }
 374 EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
 375
 376 /**
 377  * mei_cldev_register_notif_cb - register FW notification event callback
 378  *
 379  * @cldev: me client devices
 380  * @notif_cb: callback function
 381  *
 382  * Return: 0 on success
 383  *         -EALREADY if an callback is already registered
 384  *         <0 on other errors
 385  */
 386 int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
 387                                 mei_cldev_cb_t notif_cb)
 388 {
 389         struct mei_device *bus = cldev->bus;
 390         int ret;
 391
 392         if (!notif_cb)
 393                 return -EINVAL;
 394
 395         if (cldev->notif_cb)
 396                 return -EALREADY;
 397
 398         cldev->notif_cb = notif_cb;
 399         INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
 400
 401         mutex_lock(&bus->device_lock);
 402         ret = mei_cl_notify_request(cldev->cl, NULL, 1);
 403         mutex_unlock(&bus->device_lock);
 404         if (ret)
 405                 return ret;
 406
 407         return 0;
 408 }
 409 EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
 410
 411 /**
 412  * mei_cldev_get_drvdata - driver data getter
 413  *
 414  * @cldev: mei client device
 415  *
 416  * Return: driver private data
 417  */
 418 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
 419 {
 420         return dev_get_drvdata(&cldev->dev);
 421 }
 422 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
 423
 424 /**
 425  * mei_cldev_set_drvdata - driver data setter
 426  *
 427  * @cldev: mei client device
 428  * @data: data to store
 429  */
 430 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
 431 {
 432         dev_set_drvdata(&cldev->dev, data);
 433 }
 434 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
 435
 436 /**
 437  * mei_cldev_uuid - return uuid of the underlying me client
 438  *
 439  * @cldev: mei client device
 440  *
 441  * Return: me client uuid
 442  */
 443 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
 444 {
 445         return mei_me_cl_uuid(cldev->me_cl);
 446 }
 447 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
 448
 449 /**
 450  * mei_cldev_ver - return protocol version of the underlying me client
 451  *
 452  * @cldev: mei client device
 453  *
 454  * Return: me client protocol version
 455  */
 456 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
 457 {
 458         return mei_me_cl_ver(cldev->me_cl);
 459 }
 460 EXPORT_SYMBOL_GPL(mei_cldev_ver);
 461
 462 /**
 463  * mei_cldev_enabled - check whether the device is enabled
 464  *
 465  * @cldev: mei client device
 466  *
 467  * Return: true if me client is initialized and connected
 468  */
 469 bool mei_cldev_enabled(struct mei_cl_device *cldev)
 470 {
 471         return mei_cl_is_connected(cldev->cl);
 472 }
 473 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
 474
 475 /**
 476  * mei_cl_bus_module_get - acquire module of the underlying
 477  *    hw driver.
 478  *
 479  * @cldev: mei client device
 480  *
 481  * Return: true on success; false if the module was removed.
 482  */
 483 static bool mei_cl_bus_module_get(struct mei_cl_device *cldev)
 484 {
 485         return try_module_get(cldev->bus->dev->driver->owner);
 486 }
 487
 488 /**
 489  * mei_cl_bus_module_put -  release the underlying hw module.
 490  *
 491  * @cldev: mei client device
 492  */
 493 static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
 494 {
 495         module_put(cldev->bus->dev->driver->owner);
 496 }
 497
 498 /**
 499  * mei_cldev_enable - enable me client device
 500  *     create connection with me client
 501  *
 502  * @cldev: me client device
 503  *
 504  * Return: 0 on success and < 0 on error
 505  */
 506 int mei_cldev_enable(struct mei_cl_device *cldev)
 507 {
 508         struct mei_device *bus = cldev->bus;
 509         struct mei_cl *cl;
 510         int ret;
 511
 512         cl = cldev->cl;
 513
 514         mutex_lock(&bus->device_lock);
 515         if (cl->state == MEI_FILE_UNINITIALIZED) {
 516                 ret = mei_cl_link(cl);
 517                 if (ret)
 518                         goto out;
 519                 /* update pointers */
 520                 cl->cldev = cldev;
 521         }
 522
 523         if (mei_cl_is_connected(cl)) {
 524                 ret = 0;
 525                 goto out;
 526         }
 527
 528         if (!mei_me_cl_is_active(cldev->me_cl)) {
 529                 dev_err(&cldev->dev, "me client is not active\n");
 530                 ret = -ENOTTY;
 531                 goto out;
 532         }
 533
 534         ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 535         if (ret < 0)
 536                 dev_err(&cldev->dev, "cannot connect\n");
 537
 538 out:
 539         mutex_unlock(&bus->device_lock);
 540
 541         return ret;
 542 }
 543 EXPORT_SYMBOL_GPL(mei_cldev_enable);
 544
 545 /**
 546  * mei_cldev_unregister_callbacks - internal wrapper for unregistering
 547  *  callbacks.
 548  *
 549  * @cldev: client device
 550  */
 551 static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
 552 {
 553         if (cldev->rx_cb) {
 554                 cancel_work_sync(&cldev->rx_work);
 555                 cldev->rx_cb = NULL;
 556         }
 557
 558         if (cldev->notif_cb) {
 559                 cancel_work_sync(&cldev->notif_work);
 560                 cldev->notif_cb = NULL;
 561         }
 562 }
 563
 564 /**
 565  * mei_cldev_disable - disable me client device
 566  *     disconnect form the me client
 567  *
 568  * @cldev: me client device
 569  *
 570  * Return: 0 on success and < 0 on error
 571  */
 572 int mei_cldev_disable(struct mei_cl_device *cldev)
 573 {
 574         struct mei_device *bus;
 575         struct mei_cl *cl;
 576         int err;
 577
 578         if (!cldev)
 579                 return -ENODEV;
 580
 581         cl = cldev->cl;
 582
 583         bus = cldev->bus;
 584
 585         mei_cldev_unregister_callbacks(cldev);
 586
 587         mutex_lock(&bus->device_lock);
 588
 589         if (!mei_cl_is_connected(cl)) {
 590                 dev_dbg(bus->dev, "Already disconnected\n");
 591                 err = 0;
 592                 goto out;
 593         }
 594
 595         err = mei_cl_disconnect(cl);
 596         if (err < 0)
 597                 dev_err(bus->dev, "Could not disconnect from the ME client\n");
 598
 599 out:
 600         /* Flush queues and remove any pending read */
 601         mei_cl_flush_queues(cl, NULL);
 602         mei_cl_unlink(cl);
 603
 604         mutex_unlock(&bus->device_lock);
 605         return err;
 606 }
 607 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 608
 609 /**
 610  * mei_cl_device_find - find matching entry in the driver id table
 611  *
 612  * @cldev: me client device
 613  * @cldrv: me client driver
 614  *
 615  * Return: id on success; NULL if no id is matching
 616  */
 617 static const
 618 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 619                                             struct mei_cl_driver *cldrv)
 620 {
 621         const struct mei_cl_device_id *id;
 622         const uuid_le *uuid;
 623         u8 version;
 624         bool match;
 625
 626         uuid = mei_me_cl_uuid(cldev->me_cl);
 627         version = mei_me_cl_ver(cldev->me_cl);
 628
 629         id = cldrv->id_table;
 630         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 631                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 632                         match = true;
 633
 634                         if (cldev->name[0])
 635                                 if (strncmp(cldev->name, id->name,
 636                                             sizeof(id->name)))
 637                                         match = false;
 638
 639                         if (id->version != MEI_CL_VERSION_ANY)
 640                                 if (id->version != version)
 641                                         match = false;
 642                         if (match)
 643                                 return id;
 644                 }
 645
 646                 id++;
 647         }
 648
 649         return NULL;
 650 }
 651
 652 /**
 653  * mei_cl_device_match  - device match function
 654  *
 655  * @dev: device
 656  * @drv: driver
 657  *
 658  * Return:  1 if matching device was found 0 otherwise
 659  */
 660 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 661 {
 662         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 663         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 664         const struct mei_cl_device_id *found_id;
 665
 666         if (!cldev)
 667                 return 0;
 668
 669         if (!cldev->do_match)
 670                 return 0;
 671
 672         if (!cldrv || !cldrv->id_table)
 673                 return 0;
 674
 675         found_id = mei_cl_device_find(cldev, cldrv);
 676         if (found_id)
 677                 return 1;
 678
 679         return 0;
 680 }
 681
 682 /**
 683  * mei_cl_device_probe - bus probe function
 684  *
 685  * @dev: device
 686  *
 687  * Return:  0 on success; < 0 otherwise
 688  */
 689 static int mei_cl_device_probe(struct device *dev)
 690 {
 691         struct mei_cl_device *cldev;
 692         struct mei_cl_driver *cldrv;
 693         const struct mei_cl_device_id *id;
 694         int ret;
 695
 696         cldev = to_mei_cl_device(dev);
 697         cldrv = to_mei_cl_driver(dev->driver);
 698
 699         if (!cldev)
 700                 return 0;
 701
 702         if (!cldrv || !cldrv->probe)
 703                 return -ENODEV;
 704
 705         id = mei_cl_device_find(cldev, cldrv);
 706         if (!id)
 707                 return -ENODEV;
 708
 709         if (!mei_cl_bus_module_get(cldev)) {
 710                 dev_err(&cldev->dev, "get hw module failed");
 711                 return -ENODEV;
 712         }
 713
 714         ret = cldrv->probe(cldev, id);
 715         if (ret) {
 716                 mei_cl_bus_module_put(cldev);
 717                 return ret;
 718         }
 719
 720         __module_get(THIS_MODULE);
 721         return 0;
 722 }
 723
 724 /**
 725  * mei_cl_device_remove - remove device from the bus
 726  *
 727  * @dev: device
 728  *
 729  * Return:  0 on success; < 0 otherwise
 730  */
 731 static int mei_cl_device_remove(struct device *dev)
 732 {
 733         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 734         struct mei_cl_driver *cldrv;
 735         int ret = 0;
 736
 737         if (!cldev || !dev->driver)
 738                 return 0;
 739
 740         cldrv = to_mei_cl_driver(dev->driver);
 741         if (cldrv->remove)
 742                 ret = cldrv->remove(cldev);
 743
 744         mei_cldev_unregister_callbacks(cldev);
 745
 746         mei_cl_bus_module_put(cldev);
 747         module_put(THIS_MODULE);
 748         dev->driver = NULL;
 749         return ret;
 750
 751 }
 752
 753 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 754                              char *buf)
 755 {
 756         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 757
 758         return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
 759 }
 760 static DEVICE_ATTR_RO(name);
 761
 762 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 763                              char *buf)
 764 {
 765         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 766         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 767
 768         return sprintf(buf, "%pUl", uuid);
 769 }
 770 static DEVICE_ATTR_RO(uuid);
 771
 772 static ssize_t version_show(struct device *dev, struct device_attribute *a,
 773                              char *buf)
 774 {
 775         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 776         u8 version = mei_me_cl_ver(cldev->me_cl);
 777
 778         return sprintf(buf, "%02X", version);
 779 }
 780 static DEVICE_ATTR_RO(version);
 781
 782 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 783                              char *buf)
 784 {
 785         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 786         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 787         u8 version = mei_me_cl_ver(cldev->me_cl);
 788
 789         return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
 790                          cldev->name, uuid, version);
 791 }
 792 static DEVICE_ATTR_RO(modalias);
 793
 794 static ssize_t max_conn_show(struct device *dev, struct device_attribute *a,
 795                              char *buf)
 796 {
 797         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 798         u8 maxconn = mei_me_cl_max_conn(cldev->me_cl);
 799
 800         return sprintf(buf, "%d", maxconn);
 801 }
 802 static DEVICE_ATTR_RO(max_conn);
 803
 804 static ssize_t fixed_show(struct device *dev, struct device_attribute *a,
 805                           char *buf)
 806 {
 807         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 808         u8 fixed = mei_me_cl_fixed(cldev->me_cl);
 809
 810         return sprintf(buf, "%d", fixed);
 811 }
 812 static DEVICE_ATTR_RO(fixed);
 813
 814 static ssize_t max_len_show(struct device *dev, struct device_attribute *a,
 815                             char *buf)
 816 {
 817         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 818         u32 maxlen = mei_me_cl_max_len(cldev->me_cl);
 819
 820         return sprintf(buf, "%u", maxlen);
 821 }
 822 static DEVICE_ATTR_RO(max_len);
 823
 824 static struct attribute *mei_cldev_attrs[] = {
 825         &dev_attr_name.attr,
 826         &dev_attr_uuid.attr,
 827         &dev_attr_version.attr,
 828         &dev_attr_modalias.attr,
 829         &dev_attr_max_conn.attr,
 830         &dev_attr_fixed.attr,
 831         &dev_attr_max_len.attr,
 832         NULL,
 833 };
 834 ATTRIBUTE_GROUPS(mei_cldev);
 835
 836 /**
 837  * mei_cl_device_uevent - me client bus uevent handler
 838  *
 839  * @dev: device
 840  * @env: uevent kobject
 841  *
 842  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 843  */
 844 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 845 {
 846         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 847         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 848         u8 version = mei_me_cl_ver(cldev->me_cl);
 849
 850         if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
 851                 return -ENOMEM;
 852
 853         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 854                 return -ENOMEM;
 855
 856         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 857                 return -ENOMEM;
 858
 859         if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
 860                            cldev->name, uuid, version))
 861                 return -ENOMEM;
 862
 863         return 0;
 864 }
 865
 866 static struct bus_type mei_cl_bus_type = {
 867         .name           = "mei",
 868         .dev_groups     = mei_cldev_groups,
 869         .match          = mei_cl_device_match,
 870         .probe          = mei_cl_device_probe,
 871         .remove         = mei_cl_device_remove,
 872         .uevent         = mei_cl_device_uevent,
 873 };
 874
 875 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 876 {
 877         if (bus)
 878                 get_device(bus->dev);
 879
 880         return bus;
 881 }
 882
 883 static void mei_dev_bus_put(struct mei_device *bus)
 884 {
 885         if (bus)
 886                 put_device(bus->dev);
 887 }
 888
 889 static void mei_cl_bus_dev_release(struct device *dev)
 890 {
 891         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 892
 893         if (!cldev)
 894                 return;
 895
 896         mei_me_cl_put(cldev->me_cl);
 897         mei_dev_bus_put(cldev->bus);
 898         mei_cl_unlink(cldev->cl);
 899         kfree(cldev->cl);
 900         kfree(cldev);
 901 }
 902
 903 static const struct device_type mei_cl_device_type = {
 904         .release = mei_cl_bus_dev_release,
 905 };
 906
 907 /**
 908  * mei_cl_bus_set_name - set device name for me client device
 909  *  <controller>-<client device>
 910  *  Example: 0000:00:16.0-55213584-9a29-4916-badf-0fb7ed682aeb
 911  *
 912  * @cldev: me client device
 913  */
 914 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
 915 {
 916         dev_set_name(&cldev->dev, "%s-%pUl",
 917                      dev_name(cldev->bus->dev),
 918                      mei_me_cl_uuid(cldev->me_cl));
 919 }
 920
 921 /**
 922  * mei_cl_bus_dev_alloc - initialize and allocate mei client device
 923  *
 924  * @bus: mei device
 925  * @me_cl: me client
 926  *
 927  * Return: allocated device structur or NULL on allocation failure
 928  */
 929 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 930                                                   struct mei_me_client *me_cl)
 931 {
 932         struct mei_cl_device *cldev;
 933         struct mei_cl *cl;
 934
 935         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 936         if (!cldev)
 937                 return NULL;
 938
 939         cl = mei_cl_allocate(bus);
 940         if (!cl) {
 941                 kfree(cldev);
 942                 return NULL;
 943         }
 944
 945         device_initialize(&cldev->dev);
 946         cldev->dev.parent = bus->dev;
 947         cldev->dev.bus    = &mei_cl_bus_type;
 948         cldev->dev.type   = &mei_cl_device_type;
 949         cldev->bus        = mei_dev_bus_get(bus);
 950         cldev->me_cl      = mei_me_cl_get(me_cl);
 951         cldev->cl         = cl;
 952         mei_cl_bus_set_name(cldev);
 953         cldev->is_added   = 0;
 954         INIT_LIST_HEAD(&cldev->bus_list);
 955
 956         return cldev;
 957 }
 958
 959 /**
 960  * mei_cl_dev_setup - setup me client device
 961  *    run fix up routines and set the device name
 962  *
 963  * @bus: mei device
 964  * @cldev: me client device
 965  *
 966  * Return: true if the device is eligible for enumeration
 967  */
 968 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
 969                                  struct mei_cl_device *cldev)
 970 {
 971         cldev->do_match = 1;
 972         mei_cl_bus_dev_fixup(cldev);
 973
 974         /* the device name can change during fix up */
 975         if (cldev->do_match)
 976                 mei_cl_bus_set_name(cldev);
 977
 978         return cldev->do_match == 1;
 979 }
 980
 981 /**
 982  * mei_cl_bus_dev_add - add me client devices
 983  *
 984  * @cldev: me client device
 985  *
 986  * Return: 0 on success; < 0 on failre
 987  */
 988 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 989 {
 990         int ret;
 991
 992         dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
 993                 mei_me_cl_uuid(cldev->me_cl),
 994                 mei_me_cl_ver(cldev->me_cl));
 995         ret = device_add(&cldev->dev);
 996         if (!ret)
 997                 cldev->is_added = 1;
 998
 999         return ret;
1000 }
1001
1002 /**
1003  * mei_cl_bus_dev_stop - stop the driver
1004  *
1005  * @cldev: me client device
1006  */
1007 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
1008 {
1009         if (cldev->is_added)
1010                 device_release_driver(&cldev->dev);
1011 }
1012
1013 /**
1014  * mei_cl_bus_dev_destroy - destroy me client devices object
1015  *
1016  * @cldev: me client device
1017  *
1018  * Locking: called under "dev->cl_bus_lock" lock
1019  */
1020 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
1021 {
1022
1023         WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
1024
1025         if (!cldev->is_added)
1026                 return;
1027
1028         device_del(&cldev->dev);
1029
1030         list_del_init(&cldev->bus_list);
1031
1032         cldev->is_added = 0;
1033         put_device(&cldev->dev);
1034 }
1035
1036 /**
1037  * mei_cl_bus_remove_device - remove a devices form the bus
1038  *
1039  * @cldev: me client device
1040  */
1041 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
1042 {
1043         mei_cl_bus_dev_stop(cldev);
1044         mei_cl_bus_dev_destroy(cldev);
1045 }
1046
1047 /**
1048  * mei_cl_bus_remove_devices - remove all devices form the bus
1049  *
1050  * @bus: mei device
1051  */
1052 void mei_cl_bus_remove_devices(struct mei_device *bus)
1053 {
1054         struct mei_cl_device *cldev, *next;
1055
1056         mutex_lock(&bus->cl_bus_lock);
1057         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1058                 mei_cl_bus_remove_device(cldev);
1059         mutex_unlock(&bus->cl_bus_lock);
1060 }
1061
1062
1063 /**
1064  * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1065  *     based on me client
1066  *
1067  * @bus: mei device
1068  * @me_cl: me client
1069  *
1070  * Locking: called under "dev->cl_bus_lock" lock
1071  */
1072 static void mei_cl_bus_dev_init(struct mei_device *bus,
1073                                 struct mei_me_client *me_cl)
1074 {
1075         struct mei_cl_device *cldev;
1076
1077         WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1078
1079         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1080
1081         if (me_cl->bus_added)
1082                 return;
1083
1084         cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1085         if (!cldev)
1086                 return;
1087
1088         me_cl->bus_added = true;
1089         list_add_tail(&cldev->bus_list, &bus->device_list);
1090
1091 }
1092
1093 /**
1094  * mei_cl_bus_rescan - scan me clients list and add create
1095  *    devices for eligible clients
1096  *
1097  * @bus: mei device
1098  */
1099 static void mei_cl_bus_rescan(struct mei_device *bus)
1100 {
1101         struct mei_cl_device *cldev, *n;
1102         struct mei_me_client *me_cl;
1103
1104         mutex_lock(&bus->cl_bus_lock);
1105
1106         down_read(&bus->me_clients_rwsem);
1107         list_for_each_entry(me_cl, &bus->me_clients, list)
1108                 mei_cl_bus_dev_init(bus, me_cl);
1109         up_read(&bus->me_clients_rwsem);
1110
1111         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1112
1113                 if (!mei_me_cl_is_active(cldev->me_cl)) {
1114                         mei_cl_bus_remove_device(cldev);
1115                         continue;
1116                 }
1117
1118                 if (cldev->is_added)
1119                         continue;
1120
1121                 if (mei_cl_bus_dev_setup(bus, cldev))
1122                         mei_cl_bus_dev_add(cldev);
1123                 else {
1124                         list_del_init(&cldev->bus_list);
1125                         put_device(&cldev->dev);
1126                 }
1127         }
1128         mutex_unlock(&bus->cl_bus_lock);
1129
1130         dev_dbg(bus->dev, "rescan end");
1131 }
1132
1133 void mei_cl_bus_rescan_work(struct work_struct *work)
1134 {
1135         struct mei_device *bus =
1136                 container_of(work, struct mei_device, bus_rescan_work);
1137
1138         mei_cl_bus_rescan(bus);
1139 }
1140
1141 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1142                                 struct module *owner)
1143 {
1144         int err;
1145
1146         cldrv->driver.name = cldrv->name;
1147         cldrv->driver.owner = owner;
1148         cldrv->driver.bus = &mei_cl_bus_type;
1149
1150         err = driver_register(&cldrv->driver);
1151         if (err)
1152                 return err;
1153
1154         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1155
1156         return 0;
1157 }
1158 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1159
1160 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1161 {
1162         driver_unregister(&cldrv->driver);
1163
1164         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1165 }
1166 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1167
1168
1169 int __init mei_cl_bus_init(void)
1170 {
1171         return bus_register(&mei_cl_bus_type);
1172 }
1173
1174 void __exit mei_cl_bus_exit(void)
1175 {
1176         bus_unregister(&mei_cl_bus_type);
1177 }