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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (c) 2003-2020, Intel Corporation. All rights reserved.
   4 * Intel Management Engine Interface (Intel MEI) Linux driver
   5 */
   6
   7#include <linux/module.h>
   8#include <linux/moduleparam.h>
   9#include <linux/kernel.h>
  10#include <linux/device.h>
  11#include <linux/slab.h>
  12#include <linux/fs.h>
  13#include <linux/errno.h>
  14#include <linux/types.h>
  15#include <linux/fcntl.h>
  16#include <linux/poll.h>
  17#include <linux/init.h>
  18#include <linux/ioctl.h>
  19#include <linux/cdev.h>
  20#include <linux/sched/signal.h>
  21#include <linux/uuid.h>
  22#include <linux/compat.h>
  23#include <linux/jiffies.h>
  24#include <linux/interrupt.h>
  25
  26#include <linux/mei.h>
  27
  28#include "mei_dev.h"
  29#include "client.h"
  30
  31static struct class *mei_class;
  32static dev_t mei_devt;
  33#define MEI_MAX_DEVS  MINORMASK
  34static DEFINE_MUTEX(mei_minor_lock);
  35static DEFINE_IDR(mei_idr);
  36
  37/**
  38 * mei_open - the open function
  39 *
  40 * @inode: pointer to inode structure
  41 * @file: pointer to file structure
  42 *
  43 * Return: 0 on success, <0 on error
  44 */
  45static int mei_open(struct inode *inode, struct file *file)
  46{
  47	struct mei_device *dev;
  48	struct mei_cl *cl;
  49
  50	int err;
  51
  52	dev = container_of(inode->i_cdev, struct mei_device, cdev);
  53	if (!dev)
  54		return -ENODEV;
  55
  56	mutex_lock(&dev->device_lock);
  57
  58	if (dev->dev_state != MEI_DEV_ENABLED) {
  59		dev_dbg(dev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
  60		    mei_dev_state_str(dev->dev_state));
  61		err = -ENODEV;
  62		goto err_unlock;
  63	}
  64
  65	cl = mei_cl_alloc_linked(dev);
  66	if (IS_ERR(cl)) {
  67		err = PTR_ERR(cl);
  68		goto err_unlock;
  69	}
  70
  71	cl->fp = file;
  72	file->private_data = cl;
  73
  74	mutex_unlock(&dev->device_lock);
  75
  76	return nonseekable_open(inode, file);
  77
  78err_unlock:
  79	mutex_unlock(&dev->device_lock);
  80	return err;
  81}
  82
  83/**
  84 * mei_release - the release function
  85 *
  86 * @inode: pointer to inode structure
  87 * @file: pointer to file structure
  88 *
  89 * Return: 0 on success, <0 on error
  90 */
  91static int mei_release(struct inode *inode, struct file *file)
  92{
  93	struct mei_cl *cl = file->private_data;
  94	struct mei_device *dev;
  95	int rets;
  96
  97	if (WARN_ON(!cl || !cl->dev))
  98		return -ENODEV;
  99
 100	dev = cl->dev;
 101
 102	mutex_lock(&dev->device_lock);
 103
 104	rets = mei_cl_disconnect(cl);
 105
 106	mei_cl_flush_queues(cl, file);
 107	cl_dbg(dev, cl, "removing\n");
 108
 109	mei_cl_unlink(cl);
 110
 111	file->private_data = NULL;
 112
 113	kfree(cl);
 114
 115	mutex_unlock(&dev->device_lock);
 116	return rets;
 117}
 118
 119
 120/**
 121 * mei_read - the read function.
 122 *
 123 * @file: pointer to file structure
 124 * @ubuf: pointer to user buffer
 125 * @length: buffer length
 126 * @offset: data offset in buffer
 127 *
 128 * Return: >=0 data length on success , <0 on error
 129 */
 130static ssize_t mei_read(struct file *file, char __user *ubuf,
 131			size_t length, loff_t *offset)
 132{
 133	struct mei_cl *cl = file->private_data;
 134	struct mei_device *dev;
 135	struct mei_cl_cb *cb = NULL;
 136	bool nonblock = !!(file->f_flags & O_NONBLOCK);
 137	ssize_t rets;
 138
 139	if (WARN_ON(!cl || !cl->dev))
 140		return -ENODEV;
 141
 142	dev = cl->dev;
 143
 144
 145	mutex_lock(&dev->device_lock);
 146	if (dev->dev_state != MEI_DEV_ENABLED) {
 147		rets = -ENODEV;
 148		goto out;
 149	}
 150
 151	if (length == 0) {
 152		rets = 0;
 153		goto out;
 154	}
 155
 156	if (ubuf == NULL) {
 157		rets = -EMSGSIZE;
 158		goto out;
 159	}
 160
 161	cb = mei_cl_read_cb(cl, file);
 162	if (cb)
 163		goto copy_buffer;
 164
 165	if (*offset > 0)
 166		*offset = 0;
 167
 168	rets = mei_cl_read_start(cl, length, file);
 169	if (rets && rets != -EBUSY) {
 170		cl_dbg(dev, cl, "mei start read failure status = %zd\n", rets);
 171		goto out;
 172	}
 173
 174	if (nonblock) {
 175		rets = -EAGAIN;
 176		goto out;
 177	}
 178
 179	mutex_unlock(&dev->device_lock);
 180	if (wait_event_interruptible(cl->rx_wait,
 181				     !list_empty(&cl->rd_completed) ||
 182				     !mei_cl_is_connected(cl))) {
 183		if (signal_pending(current))
 184			return -EINTR;
 185		return -ERESTARTSYS;
 186	}
 187	mutex_lock(&dev->device_lock);
 188
 189	if (!mei_cl_is_connected(cl)) {
 190		rets = -ENODEV;
 191		goto out;
 192	}
 193
 194	cb = mei_cl_read_cb(cl, file);
 195	if (!cb) {
 196		rets = 0;
 197		goto out;
 198	}
 199
 200copy_buffer:
 201	/* now copy the data to user space */
 202	if (cb->status) {
 203		rets = cb->status;
 204		cl_dbg(dev, cl, "read operation failed %zd\n", rets);
 205		goto free;
 206	}
 207
 208	cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
 209	       cb->buf.size, cb->buf_idx, *offset);
 210	if (*offset >= cb->buf_idx) {
 211		rets = 0;
 212		goto free;
 213	}
 214
 215	/* length is being truncated to PAGE_SIZE,
 216	 * however buf_idx may point beyond that */
 217	length = min_t(size_t, length, cb->buf_idx - *offset);
 218
 219	if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
 220		dev_dbg(dev->dev, "failed to copy data to userland\n");
 221		rets = -EFAULT;
 222		goto free;
 223	}
 224
 225	rets = length;
 226	*offset += length;
 227	/* not all data was read, keep the cb */
 228	if (*offset < cb->buf_idx)
 229		goto out;
 230
 231free:
 232	mei_io_cb_free(cb);
 233	*offset = 0;
 234
 235out:
 236	cl_dbg(dev, cl, "end mei read rets = %zd\n", rets);
 237	mutex_unlock(&dev->device_lock);
 238	return rets;
 239}
 240/**
 241 * mei_write - the write function.
 242 *
 243 * @file: pointer to file structure
 244 * @ubuf: pointer to user buffer
 245 * @length: buffer length
 246 * @offset: data offset in buffer
 247 *
 248 * Return: >=0 data length on success , <0 on error
 249 */
 250static ssize_t mei_write(struct file *file, const char __user *ubuf,
 251			 size_t length, loff_t *offset)
 252{
 253	struct mei_cl *cl = file->private_data;
 254	struct mei_cl_cb *cb;
 255	struct mei_device *dev;
 256	ssize_t rets;
 257
 258	if (WARN_ON(!cl || !cl->dev))
 259		return -ENODEV;
 260
 261	dev = cl->dev;
 262
 263	mutex_lock(&dev->device_lock);
 264
 265	if (dev->dev_state != MEI_DEV_ENABLED) {
 266		rets = -ENODEV;
 267		goto out;
 268	}
 269
 270	if (!mei_cl_is_connected(cl)) {
 271		cl_err(dev, cl, "is not connected");
 272		rets = -ENODEV;
 273		goto out;
 274	}
 275
 276	if (!mei_me_cl_is_active(cl->me_cl)) {
 277		rets = -ENOTTY;
 278		goto out;
 279	}
 280
 281	if (length > mei_cl_mtu(cl)) {
 282		rets = -EFBIG;
 283		goto out;
 284	}
 285
 286	if (length == 0) {
 287		rets = 0;
 288		goto out;
 289	}
 290
 291	while (cl->tx_cb_queued >= dev->tx_queue_limit) {
 292		if (file->f_flags & O_NONBLOCK) {
 293			rets = -EAGAIN;
 294			goto out;
 295		}
 296		mutex_unlock(&dev->device_lock);
 297		rets = wait_event_interruptible(cl->tx_wait,
 298				cl->writing_state == MEI_WRITE_COMPLETE ||
 299				(!mei_cl_is_connected(cl)));
 300		mutex_lock(&dev->device_lock);
 301		if (rets) {
 302			if (signal_pending(current))
 303				rets = -EINTR;
 304			goto out;
 305		}
 306		if (!mei_cl_is_connected(cl)) {
 307			rets = -ENODEV;
 308			goto out;
 309		}
 310	}
 311
 312	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
 313	if (!cb) {
 314		rets = -ENOMEM;
 315		goto out;
 316	}
 317
 318	rets = copy_from_user(cb->buf.data, ubuf, length);
 319	if (rets) {
 320		dev_dbg(dev->dev, "failed to copy data from userland\n");
 321		rets = -EFAULT;
 322		mei_io_cb_free(cb);
 323		goto out;
 324	}
 325
 326	rets = mei_cl_write(cl, cb);
 327out:
 328	mutex_unlock(&dev->device_lock);
 329	return rets;
 330}
 331
 332/**
 333 * mei_ioctl_connect_client - the connect to fw client IOCTL function
 334 *
 335 * @file: private data of the file object
 336 * @data: IOCTL connect data, input and output parameters
 337 *
 338 * Locking: called under "dev->device_lock" lock
 339 *
 340 * Return: 0 on success, <0 on failure.
 341 */
 342static int mei_ioctl_connect_client(struct file *file,
 343			struct mei_connect_client_data *data)
 344{
 345	struct mei_device *dev;
 346	struct mei_client *client;
 347	struct mei_me_client *me_cl;
 348	struct mei_cl *cl;
 349	int rets;
 350
 351	cl = file->private_data;
 352	dev = cl->dev;
 353
 354	if (dev->dev_state != MEI_DEV_ENABLED)
 355		return -ENODEV;
 356
 357	if (cl->state != MEI_FILE_INITIALIZING &&
 358	    cl->state != MEI_FILE_DISCONNECTED)
 359		return  -EBUSY;
 360
 361	/* find ME client we're trying to connect to */
 362	me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
 363	if (!me_cl) {
 364		dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
 365			&data->in_client_uuid);
 366		rets = -ENOTTY;
 367		goto end;
 368	}
 369
 370	if (me_cl->props.fixed_address) {
 371		bool forbidden = dev->override_fixed_address ?
 372			 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
 373		if (forbidden) {
 374			dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
 375				&data->in_client_uuid);
 376			rets = -ENOTTY;
 377			goto end;
 378		}
 379	}
 380
 381	dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
 382			me_cl->client_id);
 383	dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
 384			me_cl->props.protocol_version);
 385	dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
 386			me_cl->props.max_msg_length);
 387
 388	/* prepare the output buffer */
 389	client = &data->out_client_properties;
 390	client->max_msg_length = me_cl->props.max_msg_length;
 391	client->protocol_version = me_cl->props.protocol_version;
 392	dev_dbg(dev->dev, "Can connect?\n");
 393
 394	rets = mei_cl_connect(cl, me_cl, file);
 395
 396end:
 397	mei_me_cl_put(me_cl);
 398	return rets;
 399}
 400
 401/**
 402 * mei_ioctl_client_notify_request -
 403 *     propagate event notification request to client
 404 *
 405 * @file: pointer to file structure
 406 * @request: 0 - disable, 1 - enable
 407 *
 408 * Return: 0 on success , <0 on error
 409 */
 410static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
 411{
 412	struct mei_cl *cl = file->private_data;
 413
 414	if (request != MEI_HBM_NOTIFICATION_START &&
 415	    request != MEI_HBM_NOTIFICATION_STOP)
 416		return -EINVAL;
 417
 418	return mei_cl_notify_request(cl, file, (u8)request);
 419}
 420
 421/**
 422 * mei_ioctl_client_notify_get -  wait for notification request
 423 *
 424 * @file: pointer to file structure
 425 * @notify_get: 0 - disable, 1 - enable
 426 *
 427 * Return: 0 on success , <0 on error
 428 */
 429static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
 430{
 431	struct mei_cl *cl = file->private_data;
 432	bool notify_ev;
 433	bool block = (file->f_flags & O_NONBLOCK) == 0;
 434	int rets;
 435
 436	rets = mei_cl_notify_get(cl, block, &notify_ev);
 437	if (rets)
 438		return rets;
 439
 440	*notify_get = notify_ev ? 1 : 0;
 441	return 0;
 442}
 443
 444/**
 445 * mei_ioctl - the IOCTL function
 446 *
 447 * @file: pointer to file structure
 448 * @cmd: ioctl command
 449 * @data: pointer to mei message structure
 450 *
 451 * Return: 0 on success , <0 on error
 452 */
 453static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 454{
 455	struct mei_device *dev;
 456	struct mei_cl *cl = file->private_data;
 457	struct mei_connect_client_data connect_data;
 458	u32 notify_get, notify_req;
 459	int rets;
 460
 461
 462	if (WARN_ON(!cl || !cl->dev))
 463		return -ENODEV;
 464
 465	dev = cl->dev;
 466
 467	dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
 468
 469	mutex_lock(&dev->device_lock);
 470	if (dev->dev_state != MEI_DEV_ENABLED) {
 471		rets = -ENODEV;
 472		goto out;
 473	}
 474
 475	switch (cmd) {
 476	case IOCTL_MEI_CONNECT_CLIENT:
 477		dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
 478		if (copy_from_user(&connect_data, (char __user *)data,
 479				   sizeof(connect_data))) {
 480			dev_dbg(dev->dev, "failed to copy data from userland\n");
 481			rets = -EFAULT;
 482			goto out;
 483		}
 484
 485		rets = mei_ioctl_connect_client(file, &connect_data);
 486		if (rets)
 487			goto out;
 488
 489		/* if all is ok, copying the data back to user. */
 490		if (copy_to_user((char __user *)data, &connect_data,
 491				 sizeof(connect_data))) {
 492			dev_dbg(dev->dev, "failed to copy data to userland\n");
 493			rets = -EFAULT;
 494			goto out;
 495		}
 496
 497		break;
 498
 499	case IOCTL_MEI_NOTIFY_SET:
 500		dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
 501		if (copy_from_user(&notify_req,
 502				   (char __user *)data, sizeof(notify_req))) {
 503			dev_dbg(dev->dev, "failed to copy data from userland\n");
 504			rets = -EFAULT;
 505			goto out;
 506		}
 507		rets = mei_ioctl_client_notify_request(file, notify_req);
 508		break;
 509
 510	case IOCTL_MEI_NOTIFY_GET:
 511		dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
 512		rets = mei_ioctl_client_notify_get(file, &notify_get);
 513		if (rets)
 514			goto out;
 515
 516		dev_dbg(dev->dev, "copy connect data to user\n");
 517		if (copy_to_user((char __user *)data,
 518				&notify_get, sizeof(notify_get))) {
 519			dev_dbg(dev->dev, "failed to copy data to userland\n");
 520			rets = -EFAULT;
 521			goto out;
 522
 523		}
 524		break;
 525
 526	default:
 527		rets = -ENOIOCTLCMD;
 528	}
 529
 530out:
 531	mutex_unlock(&dev->device_lock);
 532	return rets;
 533}
 534
 535/**
 536 * mei_poll - the poll function
 537 *
 538 * @file: pointer to file structure
 539 * @wait: pointer to poll_table structure
 540 *
 541 * Return: poll mask
 542 */
 543static __poll_t mei_poll(struct file *file, poll_table *wait)
 544{
 545	__poll_t req_events = poll_requested_events(wait);
 546	struct mei_cl *cl = file->private_data;
 547	struct mei_device *dev;
 548	__poll_t mask = 0;
 549	bool notify_en;
 550
 551	if (WARN_ON(!cl || !cl->dev))
 552		return EPOLLERR;
 553
 554	dev = cl->dev;
 555
 556	mutex_lock(&dev->device_lock);
 557
 558	notify_en = cl->notify_en && (req_events & EPOLLPRI);
 559
 560	if (dev->dev_state != MEI_DEV_ENABLED ||
 561	    !mei_cl_is_connected(cl)) {
 562		mask = EPOLLERR;
 563		goto out;
 564	}
 565
 566	if (notify_en) {
 567		poll_wait(file, &cl->ev_wait, wait);
 568		if (cl->notify_ev)
 569			mask |= EPOLLPRI;
 570	}
 571
 572	if (req_events & (EPOLLIN | EPOLLRDNORM)) {
 573		poll_wait(file, &cl->rx_wait, wait);
 574
 575		if (!list_empty(&cl->rd_completed))
 576			mask |= EPOLLIN | EPOLLRDNORM;
 577		else
 578			mei_cl_read_start(cl, mei_cl_mtu(cl), file);
 579	}
 580
 581	if (req_events & (EPOLLOUT | EPOLLWRNORM)) {
 582		poll_wait(file, &cl->tx_wait, wait);
 583		if (cl->tx_cb_queued < dev->tx_queue_limit)
 584			mask |= EPOLLOUT | EPOLLWRNORM;
 585	}
 586
 587out:
 588	mutex_unlock(&dev->device_lock);
 589	return mask;
 590}
 591
 592/**
 593 * mei_cl_is_write_queued - check if the client has pending writes.
 594 *
 595 * @cl: writing host client
 596 *
 597 * Return: true if client is writing, false otherwise.
 598 */
 599static bool mei_cl_is_write_queued(struct mei_cl *cl)
 600{
 601	struct mei_device *dev = cl->dev;
 602	struct mei_cl_cb *cb;
 603
 604	list_for_each_entry(cb, &dev->write_list, list)
 605		if (cb->cl == cl)
 606			return true;
 607	list_for_each_entry(cb, &dev->write_waiting_list, list)
 608		if (cb->cl == cl)
 609			return true;
 610	return false;
 611}
 612
 613/**
 614 * mei_fsync - the fsync handler
 615 *
 616 * @fp:       pointer to file structure
 617 * @start:    unused
 618 * @end:      unused
 619 * @datasync: unused
 620 *
 621 * Return: 0 on success, -ENODEV if client is not connected
 622 */
 623static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
 624{
 625	struct mei_cl *cl = fp->private_data;
 626	struct mei_device *dev;
 627	int rets;
 628
 629	if (WARN_ON(!cl || !cl->dev))
 630		return -ENODEV;
 631
 632	dev = cl->dev;
 633
 634	mutex_lock(&dev->device_lock);
 635
 636	if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
 637		rets = -ENODEV;
 638		goto out;
 639	}
 640
 641	while (mei_cl_is_write_queued(cl)) {
 642		mutex_unlock(&dev->device_lock);
 643		rets = wait_event_interruptible(cl->tx_wait,
 644				cl->writing_state == MEI_WRITE_COMPLETE ||
 645				!mei_cl_is_connected(cl));
 646		mutex_lock(&dev->device_lock);
 647		if (rets) {
 648			if (signal_pending(current))
 649				rets = -EINTR;
 650			goto out;
 651		}
 652		if (!mei_cl_is_connected(cl)) {
 653			rets = -ENODEV;
 654			goto out;
 655		}
 656	}
 657	rets = 0;
 658out:
 659	mutex_unlock(&dev->device_lock);
 660	return rets;
 661}
 662
 663/**
 664 * mei_fasync - asynchronous io support
 665 *
 666 * @fd: file descriptor
 667 * @file: pointer to file structure
 668 * @band: band bitmap
 669 *
 670 * Return: negative on error,
 671 *         0 if it did no changes,
 672 *         and positive a process was added or deleted
 673 */
 674static int mei_fasync(int fd, struct file *file, int band)
 675{
 676
 677	struct mei_cl *cl = file->private_data;
 678
 679	if (!mei_cl_is_connected(cl))
 680		return -ENODEV;
 681
 682	return fasync_helper(fd, file, band, &cl->ev_async);
 683}
 684
 685/**
 686 * trc_show - mei device trc attribute show method
 687 *
 688 * @device: device pointer
 689 * @attr: attribute pointer
 690 * @buf:  char out buffer
 691 *
 692 * Return: number of the bytes printed into buf or error
 693 */
 694static ssize_t trc_show(struct device *device,
 695			struct device_attribute *attr, char *buf)
 696{
 697	struct mei_device *dev = dev_get_drvdata(device);
 698	u32 trc;
 699	int ret;
 700
 701	ret = mei_trc_status(dev, &trc);
 702	if (ret)
 703		return ret;
 704	return sprintf(buf, "%08X\n", trc);
 705}
 706static DEVICE_ATTR_RO(trc);
 707
 708/**
 709 * fw_status_show - mei device fw_status attribute show method
 710 *
 711 * @device: device pointer
 712 * @attr: attribute pointer
 713 * @buf:  char out buffer
 714 *
 715 * Return: number of the bytes printed into buf or error
 716 */
 717static ssize_t fw_status_show(struct device *device,
 718		struct device_attribute *attr, char *buf)
 719{
 720	struct mei_device *dev = dev_get_drvdata(device);
 721	struct mei_fw_status fw_status;
 722	int err, i;
 723	ssize_t cnt = 0;
 724
 725	mutex_lock(&dev->device_lock);
 726	err = mei_fw_status(dev, &fw_status);
 727	mutex_unlock(&dev->device_lock);
 728	if (err) {
 729		dev_err(device, "read fw_status error = %d\n", err);
 730		return err;
 731	}
 732
 733	for (i = 0; i < fw_status.count; i++)
 734		cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
 735				fw_status.status[i]);
 736	return cnt;
 737}
 738static DEVICE_ATTR_RO(fw_status);
 739
 740/**
 741 * hbm_ver_show - display HBM protocol version negotiated with FW
 742 *
 743 * @device: device pointer
 744 * @attr: attribute pointer
 745 * @buf:  char out buffer
 746 *
 747 * Return: number of the bytes printed into buf or error
 748 */
 749static ssize_t hbm_ver_show(struct device *device,
 750			    struct device_attribute *attr, char *buf)
 751{
 752	struct mei_device *dev = dev_get_drvdata(device);
 753	struct hbm_version ver;
 754
 755	mutex_lock(&dev->device_lock);
 756	ver = dev->version;
 757	mutex_unlock(&dev->device_lock);
 758
 759	return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
 760}
 761static DEVICE_ATTR_RO(hbm_ver);
 762
 763/**
 764 * hbm_ver_drv_show - display HBM protocol version advertised by driver
 765 *
 766 * @device: device pointer
 767 * @attr: attribute pointer
 768 * @buf:  char out buffer
 769 *
 770 * Return: number of the bytes printed into buf or error
 771 */
 772static ssize_t hbm_ver_drv_show(struct device *device,
 773				struct device_attribute *attr, char *buf)
 774{
 775	return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
 776}
 777static DEVICE_ATTR_RO(hbm_ver_drv);
 778
 779static ssize_t tx_queue_limit_show(struct device *device,
 780				   struct device_attribute *attr, char *buf)
 781{
 782	struct mei_device *dev = dev_get_drvdata(device);
 783	u8 size = 0;
 784
 785	mutex_lock(&dev->device_lock);
 786	size = dev->tx_queue_limit;
 787	mutex_unlock(&dev->device_lock);
 788
 789	return snprintf(buf, PAGE_SIZE, "%u\n", size);
 790}
 791
 792static ssize_t tx_queue_limit_store(struct device *device,
 793				    struct device_attribute *attr,
 794				    const char *buf, size_t count)
 795{
 796	struct mei_device *dev = dev_get_drvdata(device);
 797	u8 limit;
 798	unsigned int inp;
 799	int err;
 800
 801	err = kstrtouint(buf, 10, &inp);
 802	if (err)
 803		return err;
 804	if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN)
 805		return -EINVAL;
 806	limit = inp;
 807
 808	mutex_lock(&dev->device_lock);
 809	dev->tx_queue_limit = limit;
 810	mutex_unlock(&dev->device_lock);
 811
 812	return count;
 813}
 814static DEVICE_ATTR_RW(tx_queue_limit);
 815
 816/**
 817 * fw_ver_show - display ME FW version
 818 *
 819 * @device: device pointer
 820 * @attr: attribute pointer
 821 * @buf:  char out buffer
 822 *
 823 * Return: number of the bytes printed into buf or error
 824 */
 825static ssize_t fw_ver_show(struct device *device,
 826			   struct device_attribute *attr, char *buf)
 827{
 828	struct mei_device *dev = dev_get_drvdata(device);
 829	struct mei_fw_version *ver;
 830	ssize_t cnt = 0;
 831	int i;
 832
 833	ver = dev->fw_ver;
 834
 835	for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
 836		cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
 837				 ver[i].platform, ver[i].major, ver[i].minor,
 838				 ver[i].hotfix, ver[i].buildno);
 839	return cnt;
 840}
 841static DEVICE_ATTR_RO(fw_ver);
 842
 843/**
 844 * dev_state_show - display device state
 845 *
 846 * @device: device pointer
 847 * @attr: attribute pointer
 848 * @buf:  char out buffer
 849 *
 850 * Return: number of the bytes printed into buf or error
 851 */
 852static ssize_t dev_state_show(struct device *device,
 853			      struct device_attribute *attr, char *buf)
 854{
 855	struct mei_device *dev = dev_get_drvdata(device);
 856	enum mei_dev_state dev_state;
 857
 858	mutex_lock(&dev->device_lock);
 859	dev_state = dev->dev_state;
 860	mutex_unlock(&dev->device_lock);
 861
 862	return sprintf(buf, "%s", mei_dev_state_str(dev_state));
 863}
 864static DEVICE_ATTR_RO(dev_state);
 865
 866/**
 867 * dev_set_devstate: set to new device state and notify sysfs file.
 868 *
 869 * @dev: mei_device
 870 * @state: new device state
 871 */
 872void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
 873{
 874	struct device *clsdev;
 875
 876	if (dev->dev_state == state)
 877		return;
 878
 879	dev->dev_state = state;
 880
 881	clsdev = class_find_device_by_devt(mei_class, dev->cdev.dev);
 882	if (clsdev) {
 883		sysfs_notify(&clsdev->kobj, NULL, "dev_state");
 884		put_device(clsdev);
 885	}
 886}
 887
 888/**
 889 * kind_show - display device kind
 890 *
 891 * @device: device pointer
 892 * @attr: attribute pointer
 893 * @buf: char out buffer
 894 *
 895 * Return: number of the bytes printed into buf or error
 896 */
 897static ssize_t kind_show(struct device *device,
 898			 struct device_attribute *attr, char *buf)
 899{
 900	struct mei_device *dev = dev_get_drvdata(device);
 901	ssize_t ret;
 902
 903	if (dev->kind)
 904		ret = sprintf(buf, "%s\n", dev->kind);
 905	else
 906		ret = sprintf(buf, "%s\n", "mei");
 907
 908	return ret;
 909}
 910static DEVICE_ATTR_RO(kind);
 911
 912static struct attribute *mei_attrs[] = {
 913	&dev_attr_fw_status.attr,
 914	&dev_attr_hbm_ver.attr,
 915	&dev_attr_hbm_ver_drv.attr,
 916	&dev_attr_tx_queue_limit.attr,
 917	&dev_attr_fw_ver.attr,
 918	&dev_attr_dev_state.attr,
 919	&dev_attr_trc.attr,
 920	&dev_attr_kind.attr,
 921	NULL
 922};
 923ATTRIBUTE_GROUPS(mei);
 924
 925/*
 926 * file operations structure will be used for mei char device.
 927 */
 928static const struct file_operations mei_fops = {
 929	.owner = THIS_MODULE,
 930	.read = mei_read,
 931	.unlocked_ioctl = mei_ioctl,
 932	.compat_ioctl = compat_ptr_ioctl,
 933	.open = mei_open,
 934	.release = mei_release,
 935	.write = mei_write,
 936	.poll = mei_poll,
 937	.fsync = mei_fsync,
 938	.fasync = mei_fasync,
 939	.llseek = no_llseek
 940};
 941
 942/**
 943 * mei_minor_get - obtain next free device minor number
 944 *
 945 * @dev:  device pointer
 946 *
 947 * Return: allocated minor, or -ENOSPC if no free minor left
 948 */
 949static int mei_minor_get(struct mei_device *dev)
 950{
 951	int ret;
 952
 953	mutex_lock(&mei_minor_lock);
 954	ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
 955	if (ret >= 0)
 956		dev->minor = ret;
 957	else if (ret == -ENOSPC)
 958		dev_err(dev->dev, "too many mei devices\n");
 959
 960	mutex_unlock(&mei_minor_lock);
 961	return ret;
 962}
 963
 964/**
 965 * mei_minor_free - mark device minor number as free
 966 *
 967 * @dev:  device pointer
 968 */
 969static void mei_minor_free(struct mei_device *dev)
 970{
 971	mutex_lock(&mei_minor_lock);
 972	idr_remove(&mei_idr, dev->minor);
 973	mutex_unlock(&mei_minor_lock);
 974}
 975
 976int mei_register(struct mei_device *dev, struct device *parent)
 977{
 978	struct device *clsdev; /* class device */
 979	int ret, devno;
 980
 981	ret = mei_minor_get(dev);
 982	if (ret < 0)
 983		return ret;
 984
 985	/* Fill in the data structures */
 986	devno = MKDEV(MAJOR(mei_devt), dev->minor);
 987	cdev_init(&dev->cdev, &mei_fops);
 988	dev->cdev.owner = parent->driver->owner;
 989
 990	/* Add the device */
 991	ret = cdev_add(&dev->cdev, devno, 1);
 992	if (ret) {
 993		dev_err(parent, "unable to add device %d:%d\n",
 994			MAJOR(mei_devt), dev->minor);
 995		goto err_dev_add;
 996	}
 997
 998	clsdev = device_create_with_groups(mei_class, parent, devno,
 999					   dev, mei_groups,
1000					   "mei%d", dev->minor);
1001
1002	if (IS_ERR(clsdev)) {
1003		dev_err(parent, "unable to create device %d:%d\n",
1004			MAJOR(mei_devt), dev->minor);
1005		ret = PTR_ERR(clsdev);
1006		goto err_dev_create;
1007	}
1008
1009	mei_dbgfs_register(dev, dev_name(clsdev));
1010
1011	return 0;
1012
1013err_dev_create:
1014	cdev_del(&dev->cdev);
1015err_dev_add:
1016	mei_minor_free(dev);
1017	return ret;
1018}
1019EXPORT_SYMBOL_GPL(mei_register);
1020
1021void mei_deregister(struct mei_device *dev)
1022{
1023	int devno;
1024
1025	devno = dev->cdev.dev;
1026	cdev_del(&dev->cdev);
1027
1028	mei_dbgfs_deregister(dev);
1029
1030	device_destroy(mei_class, devno);
1031
1032	mei_minor_free(dev);
1033}
1034EXPORT_SYMBOL_GPL(mei_deregister);
1035
1036static int __init mei_init(void)
1037{
1038	int ret;
1039
1040	mei_class = class_create(THIS_MODULE, "mei");
1041	if (IS_ERR(mei_class)) {
1042		pr_err("couldn't create class\n");
1043		ret = PTR_ERR(mei_class);
1044		goto err;
1045	}
1046
1047	ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
1048	if (ret < 0) {
1049		pr_err("unable to allocate char dev region\n");
1050		goto err_class;
1051	}
1052
1053	ret = mei_cl_bus_init();
1054	if (ret < 0) {
1055		pr_err("unable to initialize bus\n");
1056		goto err_chrdev;
1057	}
1058
1059	return 0;
1060
1061err_chrdev:
1062	unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1063err_class:
1064	class_destroy(mei_class);
1065err:
1066	return ret;
1067}
1068
1069static void __exit mei_exit(void)
1070{
1071	unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1072	class_destroy(mei_class);
1073	mei_cl_bus_exit();
1074}
1075
1076module_init(mei_init);
1077module_exit(mei_exit);
1078
1079MODULE_AUTHOR("Intel Corporation");
1080MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
1081MODULE_LICENSE("GPL v2");
1082