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   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/scatterlist.h>
  17#include <linux/mei_cl_bus.h>
  18
  19#include "mei_dev.h"
  20#include "client.h"
  21
  22#define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
  23
  24/**
  25 * __mei_cl_send - internal client send (write)
  26 *
  27 * @cl: host client
  28 * @buf: buffer to send
  29 * @length: buffer length
  30 * @vtag: virtual tag
  31 * @mode: sending mode
  32 *
  33 * Return: written size bytes or < 0 on error
  34 */
  35ssize_t __mei_cl_send(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
  36		      unsigned int mode)
  37{
  38	return __mei_cl_send_timeout(cl, buf, length, vtag, mode, MAX_SCHEDULE_TIMEOUT);
  39}
  40
  41/**
  42 * __mei_cl_send_timeout - internal client send (write)
  43 *
  44 * @cl: host client
  45 * @buf: buffer to send
  46 * @length: buffer length
  47 * @vtag: virtual tag
  48 * @mode: sending mode
  49 * @timeout: send timeout in milliseconds.
  50 *           effective only for blocking writes: the MEI_CL_IO_TX_BLOCKING mode bit is set.
  51 *           set timeout to the MAX_SCHEDULE_TIMEOUT to maixum allowed wait.
  52 *
  53 * Return: written size bytes or < 0 on error
  54 */
  55ssize_t __mei_cl_send_timeout(struct mei_cl *cl, const u8 *buf, size_t length, u8 vtag,
  56			      unsigned int mode, unsigned long timeout)
  57{
  58	struct mei_device *bus;
  59	struct mei_cl_cb *cb;
  60	ssize_t rets;
  61
  62	if (WARN_ON(!cl || !cl->dev))
  63		return -ENODEV;
  64
  65	bus = cl->dev;
  66
  67	mutex_lock(&bus->device_lock);
  68	if (bus->dev_state != MEI_DEV_ENABLED &&
  69	    bus->dev_state != MEI_DEV_POWERING_DOWN) {
  70		rets = -ENODEV;
  71		goto out;
  72	}
  73
  74	if (!mei_cl_is_connected(cl)) {
  75		rets = -ENODEV;
  76		goto out;
  77	}
  78
  79	/* Check if we have an ME client device */
  80	if (!mei_me_cl_is_active(cl->me_cl)) {
  81		rets = -ENOTTY;
  82		goto out;
  83	}
  84
  85	if (vtag) {
  86		/* Check if vtag is supported by client */
  87		rets = mei_cl_vt_support_check(cl);
  88		if (rets)
  89			goto out;
  90	}
  91
  92	if (length > mei_cl_mtu(cl)) {
  93		rets = -EFBIG;
  94		goto out;
  95	}
  96
  97	while (cl->tx_cb_queued >= bus->tx_queue_limit) {
  98		mutex_unlock(&bus->device_lock);
  99		rets = wait_event_interruptible(cl->tx_wait,
 100				cl->writing_state == MEI_WRITE_COMPLETE ||
 101				(!mei_cl_is_connected(cl)));
 102		mutex_lock(&bus->device_lock);
 103		if (rets) {
 104			if (signal_pending(current))
 105				rets = -EINTR;
 106			goto out;
 107		}
 108		if (!mei_cl_is_connected(cl)) {
 109			rets = -ENODEV;
 110			goto out;
 111		}
 112	}
 113
 114	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
 115	if (!cb) {
 116		rets = -ENOMEM;
 117		goto out;
 118	}
 119	cb->vtag = vtag;
 120
 121	cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
 122	cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
 123	memcpy(cb->buf.data, buf, length);
 124	/* hack we point data to header */
 125	if (mode & MEI_CL_IO_SGL) {
 126		cb->ext_hdr = (struct mei_ext_hdr *)cb->buf.data;
 127		cb->buf.data = NULL;
 128		cb->buf.size = 0;
 129	}
 130
 131	rets = mei_cl_write(cl, cb, timeout);
 132
 133	if (mode & MEI_CL_IO_SGL && rets == 0)
 134		rets = length;
 135
 136out:
 137	mutex_unlock(&bus->device_lock);
 138
 139	return rets;
 140}
 141
 142/**
 143 * __mei_cl_recv - internal client receive (read)
 144 *
 145 * @cl: host client
 146 * @buf: buffer to receive
 147 * @length: buffer length
 148 * @mode: io mode
 149 * @vtag: virtual tag
 150 * @timeout: recv timeout, 0 for infinite timeout
 151 *
 152 * Return: read size in bytes of < 0 on error
 153 */
 154ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length, u8 *vtag,
 155		      unsigned int mode, unsigned long timeout)
 156{
 157	struct mei_device *bus;
 158	struct mei_cl_cb *cb;
 159	size_t r_length;
 160	ssize_t rets;
 161	bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
 162
 163	if (WARN_ON(!cl || !cl->dev))
 164		return -ENODEV;
 165
 166	bus = cl->dev;
 167
 168	mutex_lock(&bus->device_lock);
 169	if (bus->dev_state != MEI_DEV_ENABLED &&
 170	    bus->dev_state != MEI_DEV_POWERING_DOWN) {
 171		rets = -ENODEV;
 172		goto out;
 173	}
 174
 175	cb = mei_cl_read_cb(cl, NULL);
 176	if (cb)
 177		goto copy;
 178
 179	rets = mei_cl_read_start(cl, length, NULL);
 180	if (rets && rets != -EBUSY)
 181		goto out;
 182
 183	if (nonblock) {
 184		rets = -EAGAIN;
 185		goto out;
 186	}
 187
 188	/* wait on event only if there is no other waiter */
 189	/* synchronized under device mutex */
 190	if (!waitqueue_active(&cl->rx_wait)) {
 191
 192		mutex_unlock(&bus->device_lock);
 193
 194		if (timeout) {
 195			rets = wait_event_interruptible_timeout
 196					(cl->rx_wait,
 197					mei_cl_read_cb(cl, NULL) ||
 198					(!mei_cl_is_connected(cl)),
 199					msecs_to_jiffies(timeout));
 200			if (rets == 0)
 201				return -ETIME;
 202			if (rets < 0) {
 203				if (signal_pending(current))
 204					return -EINTR;
 205				return -ERESTARTSYS;
 206			}
 207		} else {
 208			if (wait_event_interruptible
 209					(cl->rx_wait,
 210					mei_cl_read_cb(cl, NULL) ||
 211					(!mei_cl_is_connected(cl)))) {
 212				if (signal_pending(current))
 213					return -EINTR;
 214				return -ERESTARTSYS;
 215			}
 216		}
 217
 218		mutex_lock(&bus->device_lock);
 219
 220		if (!mei_cl_is_connected(cl)) {
 221			rets = -ENODEV;
 222			goto out;
 223		}
 224	}
 225
 226	cb = mei_cl_read_cb(cl, NULL);
 227	if (!cb) {
 228		rets = 0;
 229		goto out;
 230	}
 231
 232copy:
 233	if (cb->status) {
 234		rets = cb->status;
 235		goto free;
 236	}
 237
 238	/* for the GSC type - copy the extended header to the buffer */
 239	if (cb->ext_hdr && cb->ext_hdr->type == MEI_EXT_HDR_GSC) {
 240		r_length = min_t(size_t, length, cb->ext_hdr->length * sizeof(u32));
 241		memcpy(buf, cb->ext_hdr, r_length);
 242	} else {
 243		r_length = min_t(size_t, length, cb->buf_idx);
 244		memcpy(buf, cb->buf.data, r_length);
 245	}
 246	rets = r_length;
 247
 248	if (vtag)
 249		*vtag = cb->vtag;
 250
 251free:
 252	mei_cl_del_rd_completed(cl, cb);
 253out:
 254	mutex_unlock(&bus->device_lock);
 255
 256	return rets;
 257}
 258
 259/**
 260 * mei_cldev_send_vtag - me device send with vtag  (write)
 261 *
 262 * @cldev: me client device
 263 * @buf: buffer to send
 264 * @length: buffer length
 265 * @vtag: virtual tag
 266 *
 267 * Return:
 268 *  * written size in bytes
 269 *  * < 0 on error
 270 */
 271
 272ssize_t mei_cldev_send_vtag(struct mei_cl_device *cldev, const u8 *buf,
 273			    size_t length, u8 vtag)
 274{
 275	struct mei_cl *cl = cldev->cl;
 276
 277	return __mei_cl_send(cl, buf, length, vtag, MEI_CL_IO_TX_BLOCKING);
 278}
 279EXPORT_SYMBOL_GPL(mei_cldev_send_vtag);
 280
 281/**
 282 * mei_cldev_recv_vtag - client receive with vtag (read)
 283 *
 284 * @cldev: me client device
 285 * @buf: buffer to receive
 286 * @length: buffer length
 287 * @vtag: virtual tag
 288 *
 289 * Return:
 290 * * read size in bytes
 291 * *  < 0 on error
 292 */
 293
 294ssize_t mei_cldev_recv_vtag(struct mei_cl_device *cldev, u8 *buf, size_t length,
 295			    u8 *vtag)
 296{
 297	struct mei_cl *cl = cldev->cl;
 298
 299	return __mei_cl_recv(cl, buf, length, vtag, 0, 0);
 300}
 301EXPORT_SYMBOL_GPL(mei_cldev_recv_vtag);
 302
 303/**
 304 * mei_cldev_recv_nonblock_vtag - non block client receive with vtag (read)
 305 *
 306 * @cldev: me client device
 307 * @buf: buffer to receive
 308 * @length: buffer length
 309 * @vtag: virtual tag
 310 *
 311 * Return:
 312 * * read size in bytes
 313 * * -EAGAIN if function will block.
 314 * * < 0 on other error
 315 */
 316ssize_t mei_cldev_recv_nonblock_vtag(struct mei_cl_device *cldev, u8 *buf,
 317				     size_t length, u8 *vtag)
 318{
 319	struct mei_cl *cl = cldev->cl;
 320
 321	return __mei_cl_recv(cl, buf, length, vtag, MEI_CL_IO_RX_NONBLOCK, 0);
 322}
 323EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock_vtag);
 324
 325/**
 326 * mei_cldev_send - me device send  (write)
 327 *
 328 * @cldev: me client device
 329 * @buf: buffer to send
 330 * @length: buffer length
 331 *
 332 * Return:
 333 *  * written size in bytes
 334 *  * < 0 on error
 335 */
 336ssize_t mei_cldev_send(struct mei_cl_device *cldev, const u8 *buf, size_t length)
 337{
 338	return mei_cldev_send_vtag(cldev, buf, length, 0);
 339}
 340EXPORT_SYMBOL_GPL(mei_cldev_send);
 341
 342/**
 343 * mei_cldev_recv - client receive (read)
 344 *
 345 * @cldev: me client device
 346 * @buf: buffer to receive
 347 * @length: buffer length
 348 *
 349 * Return: read size in bytes of < 0 on error
 350 */
 351ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 352{
 353	return mei_cldev_recv_vtag(cldev, buf, length, NULL);
 354}
 355EXPORT_SYMBOL_GPL(mei_cldev_recv);
 356
 357/**
 358 * mei_cldev_recv_nonblock - non block client receive (read)
 359 *
 360 * @cldev: me client device
 361 * @buf: buffer to receive
 362 * @length: buffer length
 363 *
 364 * Return: read size in bytes of < 0 on error
 365 *         -EAGAIN if function will block.
 366 */
 367ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
 368				size_t length)
 369{
 370	return mei_cldev_recv_nonblock_vtag(cldev, buf, length, NULL);
 371}
 372EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
 373
 374/**
 375 * mei_cl_bus_rx_work - dispatch rx event for a bus device
 376 *
 377 * @work: work
 378 */
 379static void mei_cl_bus_rx_work(struct work_struct *work)
 380{
 381	struct mei_cl_device *cldev;
 382	struct mei_device *bus;
 383
 384	cldev = container_of(work, struct mei_cl_device, rx_work);
 385
 386	bus = cldev->bus;
 387
 388	if (cldev->rx_cb)
 389		cldev->rx_cb(cldev);
 390
 391	mutex_lock(&bus->device_lock);
 392	if (mei_cl_is_connected(cldev->cl))
 393		mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 394	mutex_unlock(&bus->device_lock);
 395}
 396
 397/**
 398 * mei_cl_bus_notif_work - dispatch FW notif event for a bus device
 399 *
 400 * @work: work
 401 */
 402static void mei_cl_bus_notif_work(struct work_struct *work)
 403{
 404	struct mei_cl_device *cldev;
 405
 406	cldev = container_of(work, struct mei_cl_device, notif_work);
 407
 408	if (cldev->notif_cb)
 409		cldev->notif_cb(cldev);
 410}
 411
 412/**
 413 * mei_cl_bus_notify_event - schedule notify cb on bus client
 414 *
 415 * @cl: host client
 416 *
 417 * Return: true if event was scheduled
 418 *         false if the client is not waiting for event
 419 */
 420bool mei_cl_bus_notify_event(struct mei_cl *cl)
 421{
 422	struct mei_cl_device *cldev = cl->cldev;
 423
 424	if (!cldev || !cldev->notif_cb)
 425		return false;
 426
 427	if (!cl->notify_ev)
 428		return false;
 429
 430	schedule_work(&cldev->notif_work);
 431
 432	cl->notify_ev = false;
 433
 434	return true;
 435}
 436
 437/**
 438 * mei_cl_bus_rx_event - schedule rx event
 439 *
 440 * @cl: host client
 441 *
 442 * Return: true if event was scheduled
 443 *         false if the client is not waiting for event
 444 */
 445bool mei_cl_bus_rx_event(struct mei_cl *cl)
 446{
 447	struct mei_cl_device *cldev = cl->cldev;
 448
 449	if (!cldev || !cldev->rx_cb)
 450		return false;
 451
 452	schedule_work(&cldev->rx_work);
 453
 454	return true;
 455}
 456
 457/**
 458 * mei_cldev_register_rx_cb - register Rx event callback
 459 *
 460 * @cldev: me client devices
 461 * @rx_cb: callback function
 462 *
 463 * Return: 0 on success
 464 *         -EALREADY if an callback is already registered
 465 *         <0 on other errors
 466 */
 467int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
 468{
 469	struct mei_device *bus = cldev->bus;
 470	int ret;
 471
 472	if (!rx_cb)
 473		return -EINVAL;
 474	if (cldev->rx_cb)
 475		return -EALREADY;
 476
 477	cldev->rx_cb = rx_cb;
 478	INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
 479
 480	mutex_lock(&bus->device_lock);
 481	if (mei_cl_is_connected(cldev->cl))
 482		ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
 483	else
 484		ret = -ENODEV;
 485	mutex_unlock(&bus->device_lock);
 486	if (ret && ret != -EBUSY) {
 487		cancel_work_sync(&cldev->rx_work);
 488		cldev->rx_cb = NULL;
 489		return ret;
 490	}
 491
 492	return 0;
 493}
 494EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
 495
 496/**
 497 * mei_cldev_register_notif_cb - register FW notification event callback
 498 *
 499 * @cldev: me client devices
 500 * @notif_cb: callback function
 501 *
 502 * Return: 0 on success
 503 *         -EALREADY if an callback is already registered
 504 *         <0 on other errors
 505 */
 506int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
 507				mei_cldev_cb_t notif_cb)
 508{
 509	struct mei_device *bus = cldev->bus;
 510	int ret;
 511
 512	if (!notif_cb)
 513		return -EINVAL;
 514
 515	if (cldev->notif_cb)
 516		return -EALREADY;
 517
 518	cldev->notif_cb = notif_cb;
 519	INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
 520
 521	mutex_lock(&bus->device_lock);
 522	ret = mei_cl_notify_request(cldev->cl, NULL, 1);
 523	mutex_unlock(&bus->device_lock);
 524	if (ret) {
 525		cancel_work_sync(&cldev->notif_work);
 526		cldev->notif_cb = NULL;
 527		return ret;
 528	}
 529
 530	return 0;
 531}
 532EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
 533
 534/**
 535 * mei_cldev_get_drvdata - driver data getter
 536 *
 537 * @cldev: mei client device
 538 *
 539 * Return: driver private data
 540 */
 541void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
 542{
 543	return dev_get_drvdata(&cldev->dev);
 544}
 545EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
 546
 547/**
 548 * mei_cldev_set_drvdata - driver data setter
 549 *
 550 * @cldev: mei client device
 551 * @data: data to store
 552 */
 553void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
 554{
 555	dev_set_drvdata(&cldev->dev, data);
 556}
 557EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
 558
 559/**
 560 * mei_cldev_uuid - return uuid of the underlying me client
 561 *
 562 * @cldev: mei client device
 563 *
 564 * Return: me client uuid
 565 */
 566const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
 567{
 568	return mei_me_cl_uuid(cldev->me_cl);
 569}
 570EXPORT_SYMBOL_GPL(mei_cldev_uuid);
 571
 572/**
 573 * mei_cldev_ver - return protocol version of the underlying me client
 574 *
 575 * @cldev: mei client device
 576 *
 577 * Return: me client protocol version
 578 */
 579u8 mei_cldev_ver(const struct mei_cl_device *cldev)
 580{
 581	return mei_me_cl_ver(cldev->me_cl);
 582}
 583EXPORT_SYMBOL_GPL(mei_cldev_ver);
 584
 585/**
 586 * mei_cldev_enabled - check whether the device is enabled
 587 *
 588 * @cldev: mei client device
 589 *
 590 * Return: true if me client is initialized and connected
 591 */
 592bool mei_cldev_enabled(const struct mei_cl_device *cldev)
 593{
 594	return mei_cl_is_connected(cldev->cl);
 595}
 596EXPORT_SYMBOL_GPL(mei_cldev_enabled);
 597
 598/**
 599 * mei_cl_bus_module_get - acquire module of the underlying
 600 *    hw driver.
 601 *
 602 * @cldev: mei client device
 603 *
 604 * Return: true on success; false if the module was removed.
 605 */
 606static bool mei_cl_bus_module_get(struct mei_cl_device *cldev)
 607{
 608	return try_module_get(cldev->bus->dev->driver->owner);
 609}
 610
 611/**
 612 * mei_cl_bus_module_put -  release the underlying hw module.
 613 *
 614 * @cldev: mei client device
 615 */
 616static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
 617{
 618	module_put(cldev->bus->dev->driver->owner);
 619}
 620
 621/**
 622 * mei_cl_bus_vtag - get bus vtag entry wrapper
 623 *     The tag for bus client is always first.
 624 *
 625 * @cl: host client
 626 *
 627 * Return: bus vtag or NULL
 628 */
 629static inline struct mei_cl_vtag *mei_cl_bus_vtag(struct mei_cl *cl)
 630{
 631	return list_first_entry_or_null(&cl->vtag_map,
 632					struct mei_cl_vtag, list);
 633}
 634
 635/**
 636 * mei_cl_bus_vtag_alloc - add bus client entry to vtag map
 637 *
 638 * @cldev: me client device
 639 *
 640 * Return:
 641 * * 0 on success
 642 * * -ENOMEM if memory allocation failed
 643 */
 644static int mei_cl_bus_vtag_alloc(struct mei_cl_device *cldev)
 645{
 646	struct mei_cl *cl = cldev->cl;
 647	struct mei_cl_vtag *cl_vtag;
 648
 649	/*
 650	 * Bail out if the client does not supports vtags
 651	 * or has already allocated one
 652	 */
 653	if (mei_cl_vt_support_check(cl) || mei_cl_bus_vtag(cl))
 654		return 0;
 655
 656	cl_vtag = mei_cl_vtag_alloc(NULL, 0);
 657	if (IS_ERR(cl_vtag))
 658		return -ENOMEM;
 659
 660	list_add_tail(&cl_vtag->list, &cl->vtag_map);
 661
 662	return 0;
 663}
 664
 665/**
 666 * mei_cl_bus_vtag_free - remove the bus entry from vtag map
 667 *
 668 * @cldev: me client device
 669 */
 670static void mei_cl_bus_vtag_free(struct mei_cl_device *cldev)
 671{
 672	struct mei_cl *cl = cldev->cl;
 673	struct mei_cl_vtag *cl_vtag;
 674
 675	cl_vtag = mei_cl_bus_vtag(cl);
 676	if (!cl_vtag)
 677		return;
 678
 679	list_del(&cl_vtag->list);
 680	kfree(cl_vtag);
 681}
 682
 683void *mei_cldev_dma_map(struct mei_cl_device *cldev, u8 buffer_id, size_t size)
 684{
 685	struct mei_device *bus;
 686	struct mei_cl *cl;
 687	int ret;
 688
 689	if (!cldev || !buffer_id || !size)
 690		return ERR_PTR(-EINVAL);
 691
 692	if (!IS_ALIGNED(size, MEI_FW_PAGE_SIZE)) {
 693		dev_err(&cldev->dev, "Map size should be aligned to %lu\n",
 694			MEI_FW_PAGE_SIZE);
 695		return ERR_PTR(-EINVAL);
 696	}
 697
 698	cl = cldev->cl;
 699	bus = cldev->bus;
 700
 701	mutex_lock(&bus->device_lock);
 702	if (cl->state == MEI_FILE_UNINITIALIZED) {
 703		ret = mei_cl_link(cl);
 704		if (ret)
 705			goto notlinked;
 706		/* update pointers */
 707		cl->cldev = cldev;
 708	}
 709
 710	ret = mei_cl_dma_alloc_and_map(cl, NULL, buffer_id, size);
 711	if (ret)
 712		mei_cl_unlink(cl);
 713notlinked:
 714	mutex_unlock(&bus->device_lock);
 715	if (ret)
 716		return ERR_PTR(ret);
 717	return cl->dma.vaddr;
 718}
 719EXPORT_SYMBOL_GPL(mei_cldev_dma_map);
 720
 721int mei_cldev_dma_unmap(struct mei_cl_device *cldev)
 722{
 723	struct mei_device *bus;
 724	struct mei_cl *cl;
 725	int ret;
 726
 727	if (!cldev)
 728		return -EINVAL;
 729
 730	cl = cldev->cl;
 731	bus = cldev->bus;
 732
 733	mutex_lock(&bus->device_lock);
 734	ret = mei_cl_dma_unmap(cl, NULL);
 735
 736	mei_cl_flush_queues(cl, NULL);
 737	mei_cl_unlink(cl);
 738	mutex_unlock(&bus->device_lock);
 739	return ret;
 740}
 741EXPORT_SYMBOL_GPL(mei_cldev_dma_unmap);
 742
 743/**
 744 * mei_cldev_enable - enable me client device
 745 *     create connection with me client
 746 *
 747 * @cldev: me client device
 748 *
 749 * Return: 0 on success and < 0 on error
 750 */
 751int mei_cldev_enable(struct mei_cl_device *cldev)
 752{
 753	struct mei_device *bus = cldev->bus;
 754	struct mei_cl *cl;
 755	int ret;
 756
 757	cl = cldev->cl;
 758
 759	mutex_lock(&bus->device_lock);
 760	if (cl->state == MEI_FILE_UNINITIALIZED) {
 761		ret = mei_cl_link(cl);
 762		if (ret)
 763			goto notlinked;
 764		/* update pointers */
 765		cl->cldev = cldev;
 766	}
 767
 768	if (mei_cl_is_connected(cl)) {
 769		ret = 0;
 770		goto out;
 771	}
 772
 773	if (!mei_me_cl_is_active(cldev->me_cl)) {
 774		dev_err(&cldev->dev, "me client is not active\n");
 775		ret = -ENOTTY;
 776		goto out;
 777	}
 778
 779	ret = mei_cl_bus_vtag_alloc(cldev);
 780	if (ret)
 781		goto out;
 782
 783	ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 784	if (ret < 0) {
 785		dev_err(&cldev->dev, "cannot connect\n");
 786		mei_cl_bus_vtag_free(cldev);
 787	}
 788
 789out:
 790	if (ret)
 791		mei_cl_unlink(cl);
 792notlinked:
 793	mutex_unlock(&bus->device_lock);
 794
 795	return ret;
 796}
 797EXPORT_SYMBOL_GPL(mei_cldev_enable);
 798
 799/**
 800 * mei_cldev_unregister_callbacks - internal wrapper for unregistering
 801 *  callbacks.
 802 *
 803 * @cldev: client device
 804 */
 805static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
 806{
 807	if (cldev->rx_cb) {
 808		cancel_work_sync(&cldev->rx_work);
 809		cldev->rx_cb = NULL;
 810	}
 811
 812	if (cldev->notif_cb) {
 813		cancel_work_sync(&cldev->notif_work);
 814		cldev->notif_cb = NULL;
 815	}
 816}
 817
 818/**
 819 * mei_cldev_disable - disable me client device
 820 *     disconnect form the me client
 821 *
 822 * @cldev: me client device
 823 *
 824 * Return: 0 on success and < 0 on error
 825 */
 826int mei_cldev_disable(struct mei_cl_device *cldev)
 827{
 828	struct mei_device *bus;
 829	struct mei_cl *cl;
 830	int err;
 831
 832	if (!cldev)
 833		return -ENODEV;
 834
 835	cl = cldev->cl;
 836
 837	bus = cldev->bus;
 838
 839	mei_cldev_unregister_callbacks(cldev);
 840
 841	mutex_lock(&bus->device_lock);
 842
 843	mei_cl_bus_vtag_free(cldev);
 844
 845	if (!mei_cl_is_connected(cl)) {
 846		dev_dbg(bus->dev, "Already disconnected\n");
 847		err = 0;
 848		goto out;
 849	}
 850
 851	err = mei_cl_disconnect(cl);
 852	if (err < 0)
 853		dev_err(bus->dev, "Could not disconnect from the ME client\n");
 854
 855out:
 856	/* Flush queues and remove any pending read unless we have mapped DMA */
 857	if (!cl->dma_mapped) {
 858		mei_cl_flush_queues(cl, NULL);
 859		mei_cl_unlink(cl);
 860	}
 861
 862	mutex_unlock(&bus->device_lock);
 863	return err;
 864}
 865EXPORT_SYMBOL_GPL(mei_cldev_disable);
 866
 867/**
 868 * mei_cldev_send_gsc_command - sends a gsc command, by sending
 869 * a gsl mei message to gsc and receiving reply from gsc
 870 *
 871 * @cldev: me client device
 872 * @client_id: client id to send the command to
 873 * @fence_id: fence id to send the command to
 874 * @sg_in: scatter gather list containing addresses for rx message buffer
 875 * @total_in_len: total length of data in 'in' sg, can be less than the sum of buffers sizes
 876 * @sg_out: scatter gather list containing addresses for tx message buffer
 877 *
 878 * Return:
 879 *  * written size in bytes
 880 *  * < 0 on error
 881 */
 882ssize_t mei_cldev_send_gsc_command(struct mei_cl_device *cldev,
 883				   u8 client_id, u32 fence_id,
 884				   struct scatterlist *sg_in,
 885				   size_t total_in_len,
 886				   struct scatterlist *sg_out)
 887{
 888	struct mei_cl *cl;
 889	struct mei_device *bus;
 890	ssize_t ret = 0;
 891
 892	struct mei_ext_hdr_gsc_h2f *ext_hdr;
 893	size_t buf_sz = sizeof(struct mei_ext_hdr_gsc_h2f);
 894	int sg_out_nents, sg_in_nents;
 895	int i;
 896	struct scatterlist *sg;
 897	struct mei_ext_hdr_gsc_f2h rx_msg;
 898	unsigned int sg_len;
 899
 900	if (!cldev || !sg_in || !sg_out)
 901		return -EINVAL;
 902
 903	cl = cldev->cl;
 904	bus = cldev->bus;
 905
 906	dev_dbg(bus->dev, "client_id %u, fence_id %u\n", client_id, fence_id);
 907
 908	if (!bus->hbm_f_gsc_supported)
 909		return -EOPNOTSUPP;
 910
 911	sg_out_nents = sg_nents(sg_out);
 912	sg_in_nents = sg_nents(sg_in);
 913	/* at least one entry in tx and rx sgls must be present */
 914	if (sg_out_nents <= 0 || sg_in_nents <= 0)
 915		return -EINVAL;
 916
 917	buf_sz += (sg_out_nents + sg_in_nents) * sizeof(struct mei_gsc_sgl);
 918	ext_hdr = kzalloc(buf_sz, GFP_KERNEL);
 919	if (!ext_hdr)
 920		return -ENOMEM;
 921
 922	/* construct the GSC message */
 923	ext_hdr->hdr.type = MEI_EXT_HDR_GSC;
 924	ext_hdr->hdr.length = buf_sz / sizeof(u32); /* length is in dw */
 925
 926	ext_hdr->client_id = client_id;
 927	ext_hdr->addr_type = GSC_ADDRESS_TYPE_PHYSICAL_SGL;
 928	ext_hdr->fence_id = fence_id;
 929	ext_hdr->input_address_count = sg_in_nents;
 930	ext_hdr->output_address_count = sg_out_nents;
 931	ext_hdr->reserved[0] = 0;
 932	ext_hdr->reserved[1] = 0;
 933
 934	/* copy in-sgl to the message */
 935	for (i = 0, sg = sg_in; i < sg_in_nents; i++, sg++) {
 936		ext_hdr->sgl[i].low = lower_32_bits(sg_dma_address(sg));
 937		ext_hdr->sgl[i].high = upper_32_bits(sg_dma_address(sg));
 938		sg_len = min_t(unsigned int, sg_dma_len(sg), PAGE_SIZE);
 939		ext_hdr->sgl[i].length = (sg_len <= total_in_len) ? sg_len : total_in_len;
 940		total_in_len -= ext_hdr->sgl[i].length;
 941	}
 942
 943	/* copy out-sgl to the message */
 944	for (i = sg_in_nents, sg = sg_out; i < sg_in_nents + sg_out_nents; i++, sg++) {
 945		ext_hdr->sgl[i].low = lower_32_bits(sg_dma_address(sg));
 946		ext_hdr->sgl[i].high = upper_32_bits(sg_dma_address(sg));
 947		sg_len = min_t(unsigned int, sg_dma_len(sg), PAGE_SIZE);
 948		ext_hdr->sgl[i].length = sg_len;
 949	}
 950
 951	/* send the message to GSC */
 952	ret = __mei_cl_send(cl, (u8 *)ext_hdr, buf_sz, 0, MEI_CL_IO_SGL);
 953	if (ret < 0) {
 954		dev_err(bus->dev, "__mei_cl_send failed, returned %zd\n", ret);
 955		goto end;
 956	}
 957	if (ret != buf_sz) {
 958		dev_err(bus->dev, "__mei_cl_send returned %zd instead of expected %zd\n",
 959			ret, buf_sz);
 960		ret = -EIO;
 961		goto end;
 962	}
 963
 964	/* receive the reply from GSC, note that at this point sg_in should contain the reply */
 965	ret = __mei_cl_recv(cl, (u8 *)&rx_msg, sizeof(rx_msg), NULL, MEI_CL_IO_SGL, 0);
 966
 967	if (ret != sizeof(rx_msg)) {
 968		dev_err(bus->dev, "__mei_cl_recv returned %zd instead of expected %zd\n",
 969			ret, sizeof(rx_msg));
 970		if (ret >= 0)
 971			ret = -EIO;
 972		goto end;
 973	}
 974
 975	/* check rx_msg.client_id and rx_msg.fence_id match the ones we send */
 976	if (rx_msg.client_id != client_id || rx_msg.fence_id != fence_id) {
 977		dev_err(bus->dev, "received client_id/fence_id  %u/%u  instead of %u/%u sent\n",
 978			rx_msg.client_id, rx_msg.fence_id, client_id, fence_id);
 979		ret = -EFAULT;
 980		goto end;
 981	}
 982
 983	dev_dbg(bus->dev, "gsc command: successfully written %u bytes\n",  rx_msg.written);
 984	ret = rx_msg.written;
 985
 986end:
 987	kfree(ext_hdr);
 988	return ret;
 989}
 990EXPORT_SYMBOL_GPL(mei_cldev_send_gsc_command);
 991
 992/**
 993 * mei_cl_device_find - find matching entry in the driver id table
 994 *
 995 * @cldev: me client device
 996 * @cldrv: me client driver
 997 *
 998 * Return: id on success; NULL if no id is matching
 999 */
1000static const
1001struct mei_cl_device_id *mei_cl_device_find(const struct mei_cl_device *cldev,
1002					    const struct mei_cl_driver *cldrv)
1003{
1004	const struct mei_cl_device_id *id;
1005	const uuid_le *uuid;
1006	u8 version;
1007	bool match;
1008
1009	uuid = mei_me_cl_uuid(cldev->me_cl);
1010	version = mei_me_cl_ver(cldev->me_cl);
1011
1012	id = cldrv->id_table;
1013	while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
1014		if (!uuid_le_cmp(*uuid, id->uuid)) {
1015			match = true;
1016
1017			if (cldev->name[0])
1018				if (strncmp(cldev->name, id->name,
1019					    sizeof(id->name)))
1020					match = false;
1021
1022			if (id->version != MEI_CL_VERSION_ANY)
1023				if (id->version != version)
1024					match = false;
1025			if (match)
1026				return id;
1027		}
1028
1029		id++;
1030	}
1031
1032	return NULL;
1033}
1034
1035/**
1036 * mei_cl_device_match  - device match function
1037 *
1038 * @dev: device
1039 * @drv: driver
1040 *
1041 * Return:  1 if matching device was found 0 otherwise
1042 */
1043static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
1044{
1045	const struct mei_cl_device *cldev = to_mei_cl_device(dev);
1046	const struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
1047	const struct mei_cl_device_id *found_id;
1048
1049	if (!cldev)
1050		return 0;
1051
1052	if (!cldev->do_match)
1053		return 0;
1054
1055	if (!cldrv || !cldrv->id_table)
1056		return 0;
1057
1058	found_id = mei_cl_device_find(cldev, cldrv);
1059	if (found_id)
1060		return 1;
1061
1062	return 0;
1063}
1064
1065/**
1066 * mei_cl_device_probe - bus probe function
1067 *
1068 * @dev: device
1069 *
1070 * Return:  0 on success; < 0 otherwise
1071 */
1072static int mei_cl_device_probe(struct device *dev)
1073{
1074	struct mei_cl_device *cldev;
1075	struct mei_cl_driver *cldrv;
1076	const struct mei_cl_device_id *id;
1077	int ret;
1078
1079	cldev = to_mei_cl_device(dev);
1080	cldrv = to_mei_cl_driver(dev->driver);
1081
1082	if (!cldev)
1083		return 0;
1084
1085	if (!cldrv || !cldrv->probe)
1086		return -ENODEV;
1087
1088	id = mei_cl_device_find(cldev, cldrv);
1089	if (!id)
1090		return -ENODEV;
1091
1092	if (!mei_cl_bus_module_get(cldev)) {
1093		dev_err(&cldev->dev, "get hw module failed");
1094		return -ENODEV;
1095	}
1096
1097	ret = cldrv->probe(cldev, id);
1098	if (ret) {
1099		mei_cl_bus_module_put(cldev);
1100		return ret;
1101	}
1102
1103	__module_get(THIS_MODULE);
1104	return 0;
1105}
1106
1107/**
1108 * mei_cl_device_remove - remove device from the bus
1109 *
1110 * @dev: device
1111 *
1112 * Return:  0 on success; < 0 otherwise
1113 */
1114static void mei_cl_device_remove(struct device *dev)
1115{
1116	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1117	struct mei_cl_driver *cldrv = to_mei_cl_driver(dev->driver);
1118
1119	if (cldrv->remove)
1120		cldrv->remove(cldev);
1121
1122	mei_cldev_unregister_callbacks(cldev);
1123
1124	mei_cl_bus_module_put(cldev);
1125	module_put(THIS_MODULE);
1126}
1127
1128static ssize_t name_show(struct device *dev, struct device_attribute *a,
1129			     char *buf)
1130{
1131	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1132
1133	return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
1134}
1135static DEVICE_ATTR_RO(name);
1136
1137static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
1138			     char *buf)
1139{
1140	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1141	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
1142
1143	return sprintf(buf, "%pUl", uuid);
1144}
1145static DEVICE_ATTR_RO(uuid);
1146
1147static ssize_t version_show(struct device *dev, struct device_attribute *a,
1148			     char *buf)
1149{
1150	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1151	u8 version = mei_me_cl_ver(cldev->me_cl);
1152
1153	return sprintf(buf, "%02X", version);
1154}
1155static DEVICE_ATTR_RO(version);
1156
1157static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
1158			     char *buf)
1159{
1160	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1161	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
1162	u8 version = mei_me_cl_ver(cldev->me_cl);
1163
1164	return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
1165			 cldev->name, uuid, version);
1166}
1167static DEVICE_ATTR_RO(modalias);
1168
1169static ssize_t max_conn_show(struct device *dev, struct device_attribute *a,
1170			     char *buf)
1171{
1172	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1173	u8 maxconn = mei_me_cl_max_conn(cldev->me_cl);
1174
1175	return sprintf(buf, "%d", maxconn);
1176}
1177static DEVICE_ATTR_RO(max_conn);
1178
1179static ssize_t fixed_show(struct device *dev, struct device_attribute *a,
1180			  char *buf)
1181{
1182	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1183	u8 fixed = mei_me_cl_fixed(cldev->me_cl);
1184
1185	return sprintf(buf, "%d", fixed);
1186}
1187static DEVICE_ATTR_RO(fixed);
1188
1189static ssize_t vtag_show(struct device *dev, struct device_attribute *a,
1190			 char *buf)
1191{
1192	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1193	bool vt = mei_me_cl_vt(cldev->me_cl);
1194
1195	return sprintf(buf, "%d", vt);
1196}
1197static DEVICE_ATTR_RO(vtag);
1198
1199static ssize_t max_len_show(struct device *dev, struct device_attribute *a,
1200			    char *buf)
1201{
1202	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1203	u32 maxlen = mei_me_cl_max_len(cldev->me_cl);
1204
1205	return sprintf(buf, "%u", maxlen);
1206}
1207static DEVICE_ATTR_RO(max_len);
1208
1209static struct attribute *mei_cldev_attrs[] = {
1210	&dev_attr_name.attr,
1211	&dev_attr_uuid.attr,
1212	&dev_attr_version.attr,
1213	&dev_attr_modalias.attr,
1214	&dev_attr_max_conn.attr,
1215	&dev_attr_fixed.attr,
1216	&dev_attr_vtag.attr,
1217	&dev_attr_max_len.attr,
1218	NULL,
1219};
1220ATTRIBUTE_GROUPS(mei_cldev);
1221
1222/**
1223 * mei_cl_device_uevent - me client bus uevent handler
1224 *
1225 * @dev: device
1226 * @env: uevent kobject
1227 *
1228 * Return: 0 on success -ENOMEM on when add_uevent_var fails
1229 */
1230static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
1231{
1232	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1233	const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
1234	u8 version = mei_me_cl_ver(cldev->me_cl);
1235
1236	if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
1237		return -ENOMEM;
1238
1239	if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
1240		return -ENOMEM;
1241
1242	if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
1243		return -ENOMEM;
1244
1245	if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
1246			   cldev->name, uuid, version))
1247		return -ENOMEM;
1248
1249	return 0;
1250}
1251
1252static struct bus_type mei_cl_bus_type = {
1253	.name		= "mei",
1254	.dev_groups	= mei_cldev_groups,
1255	.match		= mei_cl_device_match,
1256	.probe		= mei_cl_device_probe,
1257	.remove		= mei_cl_device_remove,
1258	.uevent		= mei_cl_device_uevent,
1259};
1260
1261static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
1262{
1263	if (bus)
1264		get_device(bus->dev);
1265
1266	return bus;
1267}
1268
1269static void mei_dev_bus_put(struct mei_device *bus)
1270{
1271	if (bus)
1272		put_device(bus->dev);
1273}
1274
1275static void mei_cl_bus_dev_release(struct device *dev)
1276{
1277	struct mei_cl_device *cldev = to_mei_cl_device(dev);
1278
1279	if (!cldev)
1280		return;
1281
1282	mei_cl_flush_queues(cldev->cl, NULL);
1283	mei_me_cl_put(cldev->me_cl);
1284	mei_dev_bus_put(cldev->bus);
1285	kfree(cldev->cl);
1286	kfree(cldev);
1287}
1288
1289static const struct device_type mei_cl_device_type = {
1290	.release = mei_cl_bus_dev_release,
1291};
1292
1293/**
1294 * mei_cl_bus_set_name - set device name for me client device
1295 *  <controller>-<client device>
1296 *  Example: 0000:00:16.0-55213584-9a29-4916-badf-0fb7ed682aeb
1297 *
1298 * @cldev: me client device
1299 */
1300static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
1301{
1302	dev_set_name(&cldev->dev, "%s-%pUl",
1303		     dev_name(cldev->bus->dev),
1304		     mei_me_cl_uuid(cldev->me_cl));
1305}
1306
1307/**
1308 * mei_cl_bus_dev_alloc - initialize and allocate mei client device
1309 *
1310 * @bus: mei device
1311 * @me_cl: me client
1312 *
1313 * Return: allocated device structur or NULL on allocation failure
1314 */
1315static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
1316						  struct mei_me_client *me_cl)
1317{
1318	struct mei_cl_device *cldev;
1319	struct mei_cl *cl;
1320
1321	cldev = kzalloc(sizeof(*cldev), GFP_KERNEL);
1322	if (!cldev)
1323		return NULL;
1324
1325	cl = mei_cl_allocate(bus);
1326	if (!cl) {
1327		kfree(cldev);
1328		return NULL;
1329	}
1330
1331	device_initialize(&cldev->dev);
1332	cldev->dev.parent = bus->dev;
1333	cldev->dev.bus    = &mei_cl_bus_type;
1334	cldev->dev.type   = &mei_cl_device_type;
1335	cldev->bus        = mei_dev_bus_get(bus);
1336	cldev->me_cl      = mei_me_cl_get(me_cl);
1337	cldev->cl         = cl;
1338	mei_cl_bus_set_name(cldev);
1339	cldev->is_added   = 0;
1340	INIT_LIST_HEAD(&cldev->bus_list);
1341
1342	return cldev;
1343}
1344
1345/**
1346 * mei_cl_bus_dev_setup - setup me client device
1347 *    run fix up routines and set the device name
1348 *
1349 * @bus: mei device
1350 * @cldev: me client device
1351 *
1352 * Return: true if the device is eligible for enumeration
1353 */
1354static bool mei_cl_bus_dev_setup(struct mei_device *bus,
1355				 struct mei_cl_device *cldev)
1356{
1357	cldev->do_match = 1;
1358	mei_cl_bus_dev_fixup(cldev);
1359
1360	/* the device name can change during fix up */
1361	if (cldev->do_match)
1362		mei_cl_bus_set_name(cldev);
1363
1364	return cldev->do_match == 1;
1365}
1366
1367/**
1368 * mei_cl_bus_dev_add - add me client devices
1369 *
1370 * @cldev: me client device
1371 *
1372 * Return: 0 on success; < 0 on failre
1373 */
1374static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
1375{
1376	int ret;
1377
1378	dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
1379		mei_me_cl_uuid(cldev->me_cl),
1380		mei_me_cl_ver(cldev->me_cl));
1381	ret = device_add(&cldev->dev);
1382	if (!ret)
1383		cldev->is_added = 1;
1384
1385	return ret;
1386}
1387
1388/**
1389 * mei_cl_bus_dev_stop - stop the driver
1390 *
1391 * @cldev: me client device
1392 */
1393static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
1394{
1395	if (cldev->is_added)
1396		device_release_driver(&cldev->dev);
1397}
1398
1399/**
1400 * mei_cl_bus_dev_destroy - destroy me client devices object
1401 *
1402 * @cldev: me client device
1403 *
1404 * Locking: called under "dev->cl_bus_lock" lock
1405 */
1406static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
1407{
1408
1409	WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
1410
1411	if (!cldev->is_added)
1412		return;
1413
1414	device_del(&cldev->dev);
1415
1416	list_del_init(&cldev->bus_list);
1417
1418	cldev->is_added = 0;
1419	put_device(&cldev->dev);
1420}
1421
1422/**
1423 * mei_cl_bus_remove_device - remove a devices form the bus
1424 *
1425 * @cldev: me client device
1426 */
1427static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
1428{
1429	mei_cl_bus_dev_stop(cldev);
1430	mei_cl_bus_dev_destroy(cldev);
1431}
1432
1433/**
1434 * mei_cl_bus_remove_devices - remove all devices form the bus
1435 *
1436 * @bus: mei device
1437 */
1438void mei_cl_bus_remove_devices(struct mei_device *bus)
1439{
1440	struct mei_cl_device *cldev, *next;
1441
1442	mutex_lock(&bus->cl_bus_lock);
1443	list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1444		mei_cl_bus_remove_device(cldev);
1445	mutex_unlock(&bus->cl_bus_lock);
1446}
1447
1448
1449/**
1450 * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1451 *     based on me client
1452 *
1453 * @bus: mei device
1454 * @me_cl: me client
1455 *
1456 * Locking: called under "dev->cl_bus_lock" lock
1457 */
1458static void mei_cl_bus_dev_init(struct mei_device *bus,
1459				struct mei_me_client *me_cl)
1460{
1461	struct mei_cl_device *cldev;
1462
1463	WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1464
1465	dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1466
1467	if (me_cl->bus_added)
1468		return;
1469
1470	cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1471	if (!cldev)
1472		return;
1473
1474	me_cl->bus_added = true;
1475	list_add_tail(&cldev->bus_list, &bus->device_list);
1476
1477}
1478
1479/**
1480 * mei_cl_bus_rescan - scan me clients list and add create
1481 *    devices for eligible clients
1482 *
1483 * @bus: mei device
1484 */
1485static void mei_cl_bus_rescan(struct mei_device *bus)
1486{
1487	struct mei_cl_device *cldev, *n;
1488	struct mei_me_client *me_cl;
1489
1490	mutex_lock(&bus->cl_bus_lock);
1491
1492	down_read(&bus->me_clients_rwsem);
1493	list_for_each_entry(me_cl, &bus->me_clients, list)
1494		mei_cl_bus_dev_init(bus, me_cl);
1495	up_read(&bus->me_clients_rwsem);
1496
1497	list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1498
1499		if (!mei_me_cl_is_active(cldev->me_cl)) {
1500			mei_cl_bus_remove_device(cldev);
1501			continue;
1502		}
1503
1504		if (cldev->is_added)
1505			continue;
1506
1507		if (mei_cl_bus_dev_setup(bus, cldev))
1508			mei_cl_bus_dev_add(cldev);
1509		else {
1510			list_del_init(&cldev->bus_list);
1511			put_device(&cldev->dev);
1512		}
1513	}
1514	mutex_unlock(&bus->cl_bus_lock);
1515
1516	dev_dbg(bus->dev, "rescan end");
1517}
1518
1519void mei_cl_bus_rescan_work(struct work_struct *work)
1520{
1521	struct mei_device *bus =
1522		container_of(work, struct mei_device, bus_rescan_work);
1523
1524	mei_cl_bus_rescan(bus);
1525}
1526
1527int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1528				struct module *owner)
1529{
1530	int err;
1531
1532	cldrv->driver.name = cldrv->name;
1533	cldrv->driver.owner = owner;
1534	cldrv->driver.bus = &mei_cl_bus_type;
1535
1536	err = driver_register(&cldrv->driver);
1537	if (err)
1538		return err;
1539
1540	pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1541
1542	return 0;
1543}
1544EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1545
1546void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1547{
1548	driver_unregister(&cldrv->driver);
1549
1550	pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1551}
1552EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1553
1554
1555int __init mei_cl_bus_init(void)
1556{
1557	return bus_register(&mei_cl_bus_type);
1558}
1559
1560void __exit mei_cl_bus_exit(void)
1561{
1562	bus_unregister(&mei_cl_bus_type);
1563}