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