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         err = mei_cl_disconnect(cl);
 552         if (err < 0)
 553                 dev_err(bus->dev, "Could not disconnect from the ME client\n");
 554
 555 out:
 556         /* Flush queues and remove any pending read */
 557         mei_cl_flush_queues(cl, NULL);
 558         mei_cl_unlink(cl);
 559
 560         mutex_unlock(&bus->device_lock);
 561         return err;
 562 }
 563 EXPORT_SYMBOL_GPL(mei_cldev_disable);
 564
 565 /**
 566  * mei_cl_bus_module_get - acquire module of the underlying
 567  *    hw module.
 568  *
 569  * @cl: host client
 570  *
 571  * Return: true on success; false if the module was removed.
 572  */
 573 bool mei_cl_bus_module_get(struct mei_cl *cl)
 574 {
 575         struct mei_cl_device *cldev = cl->cldev;
 576
 577         if (!cldev)
 578                 return true;
 579
 580         return try_module_get(cldev->bus->dev->driver->owner);
 581 }
 582
 583 /**
 584  * mei_cl_bus_module_put -  release the underlying hw module.
 585  *
 586  * @cl: host client
 587  */
 588 void mei_cl_bus_module_put(struct mei_cl *cl)
 589 {
 590         struct mei_cl_device *cldev = cl->cldev;
 591
 592         if (cldev)
 593                 module_put(cldev->bus->dev->driver->owner);
 594 }
 595
 596 /**
 597  * mei_cl_device_find - find matching entry in the driver id table
 598  *
 599  * @cldev: me client device
 600  * @cldrv: me client driver
 601  *
 602  * Return: id on success; NULL if no id is matching
 603  */
 604 static const
 605 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
 606                                             struct mei_cl_driver *cldrv)
 607 {
 608         const struct mei_cl_device_id *id;
 609         const uuid_le *uuid;
 610         u8 version;
 611         bool match;
 612
 613         uuid = mei_me_cl_uuid(cldev->me_cl);
 614         version = mei_me_cl_ver(cldev->me_cl);
 615
 616         id = cldrv->id_table;
 617         while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
 618                 if (!uuid_le_cmp(*uuid, id->uuid)) {
 619                         match = true;
 620
 621                         if (cldev->name[0])
 622                                 if (strncmp(cldev->name, id->name,
 623                                             sizeof(id->name)))
 624                                         match = false;
 625
 626                         if (id->version != MEI_CL_VERSION_ANY)
 627                                 if (id->version != version)
 628                                         match = false;
 629                         if (match)
 630                                 return id;
 631                 }
 632
 633                 id++;
 634         }
 635
 636         return NULL;
 637 }
 638
 639 /**
 640  * mei_cl_device_match  - device match function
 641  *
 642  * @dev: device
 643  * @drv: driver
 644  *
 645  * Return:  1 if matching device was found 0 otherwise
 646  */
 647 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
 648 {
 649         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 650         struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
 651         const struct mei_cl_device_id *found_id;
 652
 653         if (!cldev)
 654                 return 0;
 655
 656         if (!cldev->do_match)
 657                 return 0;
 658
 659         if (!cldrv || !cldrv->id_table)
 660                 return 0;
 661
 662         found_id = mei_cl_device_find(cldev, cldrv);
 663         if (found_id)
 664                 return 1;
 665
 666         return 0;
 667 }
 668
 669 /**
 670  * mei_cl_device_probe - bus probe function
 671  *
 672  * @dev: device
 673  *
 674  * Return:  0 on success; < 0 otherwise
 675  */
 676 static int mei_cl_device_probe(struct device *dev)
 677 {
 678         struct mei_cl_device *cldev;
 679         struct mei_cl_driver *cldrv;
 680         const struct mei_cl_device_id *id;
 681         int ret;
 682
 683         cldev = to_mei_cl_device(dev);
 684         cldrv = to_mei_cl_driver(dev->driver);
 685
 686         if (!cldev)
 687                 return 0;
 688
 689         if (!cldrv || !cldrv->probe)
 690                 return -ENODEV;
 691
 692         id = mei_cl_device_find(cldev, cldrv);
 693         if (!id)
 694                 return -ENODEV;
 695
 696         ret = cldrv->probe(cldev, id);
 697         if (ret)
 698                 return ret;
 699
 700         __module_get(THIS_MODULE);
 701         return 0;
 702 }
 703
 704 /**
 705  * mei_cl_device_remove - remove device from the bus
 706  *
 707  * @dev: device
 708  *
 709  * Return:  0 on success; < 0 otherwise
 710  */
 711 static int mei_cl_device_remove(struct device *dev)
 712 {
 713         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 714         struct mei_cl_driver *cldrv;
 715         int ret = 0;
 716
 717         if (!cldev || !dev->driver)
 718                 return 0;
 719
 720         cldrv = to_mei_cl_driver(dev->driver);
 721         if (cldrv->remove)
 722                 ret = cldrv->remove(cldev);
 723
 724         mei_cldev_unregister_callbacks(cldev);
 725
 726         module_put(THIS_MODULE);
 727         dev->driver = NULL;
 728         return ret;
 729
 730 }
 731
 732 static ssize_t name_show(struct device *dev, struct device_attribute *a,
 733                              char *buf)
 734 {
 735         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 736
 737         return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
 738 }
 739 static DEVICE_ATTR_RO(name);
 740
 741 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
 742                              char *buf)
 743 {
 744         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 745         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 746
 747         return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
 748 }
 749 static DEVICE_ATTR_RO(uuid);
 750
 751 static ssize_t version_show(struct device *dev, struct device_attribute *a,
 752                              char *buf)
 753 {
 754         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 755         u8 version = mei_me_cl_ver(cldev->me_cl);
 756
 757         return scnprintf(buf, PAGE_SIZE, "%02X", version);
 758 }
 759 static DEVICE_ATTR_RO(version);
 760
 761 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 762                              char *buf)
 763 {
 764         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 765         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 766         u8 version = mei_me_cl_ver(cldev->me_cl);
 767
 768         return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
 769                          cldev->name, uuid, version);
 770 }
 771 static DEVICE_ATTR_RO(modalias);
 772
 773 static struct attribute *mei_cldev_attrs[] = {
 774         &dev_attr_name.attr,
 775         &dev_attr_uuid.attr,
 776         &dev_attr_version.attr,
 777         &dev_attr_modalias.attr,
 778         NULL,
 779 };
 780 ATTRIBUTE_GROUPS(mei_cldev);
 781
 782 /**
 783  * mei_cl_device_uevent - me client bus uevent handler
 784  *
 785  * @dev: device
 786  * @env: uevent kobject
 787  *
 788  * Return: 0 on success -ENOMEM on when add_uevent_var fails
 789  */
 790 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 791 {
 792         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 793         const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
 794         u8 version = mei_me_cl_ver(cldev->me_cl);
 795
 796         if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
 797                 return -ENOMEM;
 798
 799         if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
 800                 return -ENOMEM;
 801
 802         if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
 803                 return -ENOMEM;
 804
 805         if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
 806                            cldev->name, uuid, version))
 807                 return -ENOMEM;
 808
 809         return 0;
 810 }
 811
 812 static struct bus_type mei_cl_bus_type = {
 813         .name           = "mei",
 814         .dev_groups     = mei_cldev_groups,
 815         .match          = mei_cl_device_match,
 816         .probe          = mei_cl_device_probe,
 817         .remove         = mei_cl_device_remove,
 818         .uevent         = mei_cl_device_uevent,
 819 };
 820
 821 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
 822 {
 823         if (bus)
 824                 get_device(bus->dev);
 825
 826         return bus;
 827 }
 828
 829 static void mei_dev_bus_put(struct mei_device *bus)
 830 {
 831         if (bus)
 832                 put_device(bus->dev);
 833 }
 834
 835 static void mei_cl_bus_dev_release(struct device *dev)
 836 {
 837         struct mei_cl_device *cldev = to_mei_cl_device(dev);
 838
 839         if (!cldev)
 840                 return;
 841
 842         mei_me_cl_put(cldev->me_cl);
 843         mei_dev_bus_put(cldev->bus);
 844         kfree(cldev->cl);
 845         kfree(cldev);
 846 }
 847
 848 static const struct device_type mei_cl_device_type = {
 849         .release        = mei_cl_bus_dev_release,
 850 };
 851
 852 /**
 853  * mei_cl_bus_set_name - set device name for me client device
 854  *
 855  * @cldev: me client device
 856  */
 857 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
 858 {
 859         dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
 860                      cldev->name,
 861                      mei_me_cl_uuid(cldev->me_cl),
 862                      mei_me_cl_ver(cldev->me_cl));
 863 }
 864
 865 /**
 866  * mei_cl_bus_dev_alloc - initialize and allocate mei client device
 867  *
 868  * @bus: mei device
 869  * @me_cl: me client
 870  *
 871  * Return: allocated device structur or NULL on allocation failure
 872  */
 873 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 874                                                   struct mei_me_client *me_cl)
 875 {
 876         struct mei_cl_device *cldev;
 877         struct mei_cl *cl;
 878
 879         cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
 880         if (!cldev)
 881                 return NULL;
 882
 883         cl = mei_cl_allocate(bus);
 884         if (!cl) {
 885                 kfree(cldev);
 886                 return NULL;
 887         }
 888
 889         device_initialize(&cldev->dev);
 890         cldev->dev.parent = bus->dev;
 891         cldev->dev.bus    = &mei_cl_bus_type;
 892         cldev->dev.type   = &mei_cl_device_type;
 893         cldev->bus        = mei_dev_bus_get(bus);
 894         cldev->me_cl      = mei_me_cl_get(me_cl);
 895         cldev->cl         = cl;
 896         mei_cl_bus_set_name(cldev);
 897         cldev->is_added   = 0;
 898         INIT_LIST_HEAD(&cldev->bus_list);
 899
 900         return cldev;
 901 }
 902
 903 /**
 904  * mei_cl_dev_setup - setup me client device
 905  *    run fix up routines and set the device name
 906  *
 907  * @bus: mei device
 908  * @cldev: me client device
 909  *
 910  * Return: true if the device is eligible for enumeration
 911  */
 912 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
 913                                  struct mei_cl_device *cldev)
 914 {
 915         cldev->do_match = 1;
 916         mei_cl_bus_dev_fixup(cldev);
 917
 918         /* the device name can change during fix up */
 919         if (cldev->do_match)
 920                 mei_cl_bus_set_name(cldev);
 921
 922         return cldev->do_match == 1;
 923 }
 924
 925 /**
 926  * mei_cl_bus_dev_add - add me client devices
 927  *
 928  * @cldev: me client device
 929  *
 930  * Return: 0 on success; < 0 on failre
 931  */
 932 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
 933 {
 934         int ret;
 935
 936         dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
 937                 mei_me_cl_uuid(cldev->me_cl),
 938                 mei_me_cl_ver(cldev->me_cl));
 939         ret = device_add(&cldev->dev);
 940         if (!ret)
 941                 cldev->is_added = 1;
 942
 943         return ret;
 944 }
 945
 946 /**
 947  * mei_cl_bus_dev_stop - stop the driver
 948  *
 949  * @cldev: me client device
 950  */
 951 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
 952 {
 953         if (cldev->is_added)
 954                 device_release_driver(&cldev->dev);
 955 }
 956
 957 /**
 958  * mei_cl_bus_dev_destroy - destroy me client devices object
 959  *
 960  * @cldev: me client device
 961  *
 962  * Locking: called under "dev->cl_bus_lock" lock
 963  */
 964 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
 965 {
 966
 967         WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
 968
 969         if (!cldev->is_added)
 970                 return;
 971
 972         device_del(&cldev->dev);
 973
 974         list_del_init(&cldev->bus_list);
 975
 976         cldev->is_added = 0;
 977         put_device(&cldev->dev);
 978 }
 979
 980 /**
 981  * mei_cl_bus_remove_device - remove a devices form the bus
 982  *
 983  * @cldev: me client device
 984  */
 985 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
 986 {
 987         mei_cl_bus_dev_stop(cldev);
 988         mei_cl_bus_dev_destroy(cldev);
 989 }
 990
 991 /**
 992  * mei_cl_bus_remove_devices - remove all devices form the bus
 993  *
 994  * @bus: mei device
 995  */
 996 void mei_cl_bus_remove_devices(struct mei_device *bus)
 997 {
 998         struct mei_cl_device *cldev, *next;
 999
1000         mutex_lock(&bus->cl_bus_lock);
1001         list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1002                 mei_cl_bus_remove_device(cldev);
1003         mutex_unlock(&bus->cl_bus_lock);
1004 }
1005
1006
1007 /**
1008  * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1009  *     based on me client
1010  *
1011  * @bus: mei device
1012  * @me_cl: me client
1013  *
1014  * Locking: called under "dev->cl_bus_lock" lock
1015  */
1016 static void mei_cl_bus_dev_init(struct mei_device *bus,
1017                                 struct mei_me_client *me_cl)
1018 {
1019         struct mei_cl_device *cldev;
1020
1021         WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1022
1023         dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1024
1025         if (me_cl->bus_added)
1026                 return;
1027
1028         cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1029         if (!cldev)
1030                 return;
1031
1032         me_cl->bus_added = true;
1033         list_add_tail(&cldev->bus_list, &bus->device_list);
1034
1035 }
1036
1037 /**
1038  * mei_cl_bus_rescan - scan me clients list and add create
1039  *    devices for eligible clients
1040  *
1041  * @bus: mei device
1042  */
1043 static void mei_cl_bus_rescan(struct mei_device *bus)
1044 {
1045         struct mei_cl_device *cldev, *n;
1046         struct mei_me_client *me_cl;
1047
1048         mutex_lock(&bus->cl_bus_lock);
1049
1050         down_read(&bus->me_clients_rwsem);
1051         list_for_each_entry(me_cl, &bus->me_clients, list)
1052                 mei_cl_bus_dev_init(bus, me_cl);
1053         up_read(&bus->me_clients_rwsem);
1054
1055         list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1056
1057                 if (!mei_me_cl_is_active(cldev->me_cl)) {
1058                         mei_cl_bus_remove_device(cldev);
1059                         continue;
1060                 }
1061
1062                 if (cldev->is_added)
1063                         continue;
1064
1065                 if (mei_cl_bus_dev_setup(bus, cldev))
1066                         mei_cl_bus_dev_add(cldev);
1067                 else {
1068                         list_del_init(&cldev->bus_list);
1069                         put_device(&cldev->dev);
1070                 }
1071         }
1072         mutex_unlock(&bus->cl_bus_lock);
1073
1074         dev_dbg(bus->dev, "rescan end");
1075 }
1076
1077 void mei_cl_bus_rescan_work(struct work_struct *work)
1078 {
1079         struct mei_device *bus =
1080                 container_of(work, struct mei_device, bus_rescan_work);
1081
1082         mei_cl_bus_rescan(bus);
1083 }
1084
1085 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1086                                 struct module *owner)
1087 {
1088         int err;
1089
1090         cldrv->driver.name = cldrv->name;
1091         cldrv->driver.owner = owner;
1092         cldrv->driver.bus = &mei_cl_bus_type;
1093
1094         err = driver_register(&cldrv->driver);
1095         if (err)
1096                 return err;
1097
1098         pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1099
1100         return 0;
1101 }
1102 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1103
1104 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1105 {
1106         driver_unregister(&cldrv->driver);
1107
1108         pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1109 }
1110 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1111
1112
1113 int __init mei_cl_bus_init(void)
1114 {
1115         return bus_register(&mei_cl_bus_type);
1116 }
1117
1118 void __exit mei_cl_bus_exit(void)
1119 {
1120         bus_unregister(&mei_cl_bus_type);
1121 }