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1/*
2 *
3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2012, Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 */
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/slab.h>
21#include <linux/fs.h>
22#include <linux/errno.h>
23#include <linux/types.h>
24#include <linux/fcntl.h>
25#include <linux/poll.h>
26#include <linux/init.h>
27#include <linux/ioctl.h>
28#include <linux/cdev.h>
29#include <linux/sched.h>
30#include <linux/uuid.h>
31#include <linux/compat.h>
32#include <linux/jiffies.h>
33#include <linux/interrupt.h>
34
35#include <linux/mei.h>
36
37#include "mei_dev.h"
38#include "client.h"
39
40/**
41 * mei_open - the open function
42 *
43 * @inode: pointer to inode structure
44 * @file: pointer to file structure
45 *
46 * Return: 0 on success, <0 on error
47 */
48static int mei_open(struct inode *inode, struct file *file)
49{
50 struct mei_device *dev;
51 struct mei_cl *cl;
52
53 int err;
54
55 dev = container_of(inode->i_cdev, struct mei_device, cdev);
56 if (!dev)
57 return -ENODEV;
58
59 mutex_lock(&dev->device_lock);
60
61 if (dev->dev_state != MEI_DEV_ENABLED) {
62 dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
63 mei_dev_state_str(dev->dev_state));
64 err = -ENODEV;
65 goto err_unlock;
66 }
67
68 cl = mei_cl_alloc_linked(dev);
69 if (IS_ERR(cl)) {
70 err = PTR_ERR(cl);
71 goto err_unlock;
72 }
73
74 file->private_data = cl;
75
76 mutex_unlock(&dev->device_lock);
77
78 return nonseekable_open(inode, file);
79
80err_unlock:
81 mutex_unlock(&dev->device_lock);
82 return err;
83}
84
85/**
86 * mei_release - the release function
87 *
88 * @inode: pointer to inode structure
89 * @file: pointer to file structure
90 *
91 * Return: 0 on success, <0 on error
92 */
93static int mei_release(struct inode *inode, struct file *file)
94{
95 struct mei_cl *cl = file->private_data;
96 struct mei_device *dev;
97 int rets;
98
99 if (WARN_ON(!cl || !cl->dev))
100 return -ENODEV;
101
102 dev = cl->dev;
103
104 mutex_lock(&dev->device_lock);
105 if (cl == &dev->iamthif_cl) {
106 rets = mei_amthif_release(dev, file);
107 goto out;
108 }
109 rets = mei_cl_disconnect(cl);
110
111 mei_cl_flush_queues(cl, file);
112 cl_dbg(dev, cl, "removing\n");
113
114 mei_cl_unlink(cl);
115
116 file->private_data = NULL;
117
118 kfree(cl);
119out:
120 mutex_unlock(&dev->device_lock);
121 return rets;
122}
123
124
125/**
126 * mei_read - the read function.
127 *
128 * @file: pointer to file structure
129 * @ubuf: pointer to user buffer
130 * @length: buffer length
131 * @offset: data offset in buffer
132 *
133 * Return: >=0 data length on success , <0 on error
134 */
135static ssize_t mei_read(struct file *file, char __user *ubuf,
136 size_t length, loff_t *offset)
137{
138 struct mei_cl *cl = file->private_data;
139 struct mei_device *dev;
140 struct mei_cl_cb *cb = NULL;
141 int rets;
142 int err;
143
144
145 if (WARN_ON(!cl || !cl->dev))
146 return -ENODEV;
147
148 dev = cl->dev;
149
150
151 mutex_lock(&dev->device_lock);
152 if (dev->dev_state != MEI_DEV_ENABLED) {
153 rets = -ENODEV;
154 goto out;
155 }
156
157 if (length == 0) {
158 rets = 0;
159 goto out;
160 }
161
162 if (ubuf == NULL) {
163 rets = -EMSGSIZE;
164 goto out;
165 }
166
167 if (cl == &dev->iamthif_cl) {
168 rets = mei_amthif_read(dev, file, ubuf, length, offset);
169 goto out;
170 }
171
172 cb = mei_cl_read_cb(cl, file);
173 if (cb)
174 goto copy_buffer;
175
176 if (*offset > 0)
177 *offset = 0;
178
179 err = mei_cl_read_start(cl, length, file);
180 if (err && err != -EBUSY) {
181 cl_dbg(dev, cl, "mei start read failure status = %d\n", err);
182 rets = err;
183 goto out;
184 }
185
186 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
187 if (file->f_flags & O_NONBLOCK) {
188 rets = -EAGAIN;
189 goto out;
190 }
191
192 mutex_unlock(&dev->device_lock);
193
194 if (wait_event_interruptible(cl->rx_wait,
195 (!list_empty(&cl->rd_completed)) ||
196 (!mei_cl_is_connected(cl)))) {
197
198 if (signal_pending(current))
199 return -EINTR;
200 return -ERESTARTSYS;
201 }
202
203 mutex_lock(&dev->device_lock);
204 if (!mei_cl_is_connected(cl)) {
205 rets = -EBUSY;
206 goto out;
207 }
208 }
209
210 cb = mei_cl_read_cb(cl, file);
211 if (!cb) {
212 rets = 0;
213 goto out;
214 }
215
216copy_buffer:
217 /* now copy the data to user space */
218 if (cb->status) {
219 rets = cb->status;
220 cl_dbg(dev, cl, "read operation failed %d\n", rets);
221 goto free;
222 }
223
224 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
225 cb->buf.size, cb->buf_idx, *offset);
226 if (*offset >= cb->buf_idx) {
227 rets = 0;
228 goto free;
229 }
230
231 /* length is being truncated to PAGE_SIZE,
232 * however buf_idx may point beyond that */
233 length = min_t(size_t, length, cb->buf_idx - *offset);
234
235 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
236 dev_dbg(dev->dev, "failed to copy data to userland\n");
237 rets = -EFAULT;
238 goto free;
239 }
240
241 rets = length;
242 *offset += length;
243 /* not all data was read, keep the cb */
244 if (*offset < cb->buf_idx)
245 goto out;
246
247free:
248 mei_io_cb_free(cb);
249 *offset = 0;
250
251out:
252 cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
253 mutex_unlock(&dev->device_lock);
254 return rets;
255}
256/**
257 * mei_write - the write function.
258 *
259 * @file: pointer to file structure
260 * @ubuf: pointer to user buffer
261 * @length: buffer length
262 * @offset: data offset in buffer
263 *
264 * Return: >=0 data length on success , <0 on error
265 */
266static ssize_t mei_write(struct file *file, const char __user *ubuf,
267 size_t length, loff_t *offset)
268{
269 struct mei_cl *cl = file->private_data;
270 struct mei_cl_cb *cb;
271 struct mei_device *dev;
272 int rets;
273
274 if (WARN_ON(!cl || !cl->dev))
275 return -ENODEV;
276
277 dev = cl->dev;
278
279 mutex_lock(&dev->device_lock);
280
281 if (dev->dev_state != MEI_DEV_ENABLED) {
282 rets = -ENODEV;
283 goto out;
284 }
285
286 if (!mei_cl_is_connected(cl)) {
287 cl_err(dev, cl, "is not connected");
288 rets = -ENODEV;
289 goto out;
290 }
291
292 if (!mei_me_cl_is_active(cl->me_cl)) {
293 rets = -ENOTTY;
294 goto out;
295 }
296
297 if (length > mei_cl_mtu(cl)) {
298 rets = -EFBIG;
299 goto out;
300 }
301
302 if (length == 0) {
303 rets = 0;
304 goto out;
305 }
306
307 *offset = 0;
308 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
309 if (!cb) {
310 rets = -ENOMEM;
311 goto out;
312 }
313
314 rets = copy_from_user(cb->buf.data, ubuf, length);
315 if (rets) {
316 dev_dbg(dev->dev, "failed to copy data from userland\n");
317 rets = -EFAULT;
318 mei_io_cb_free(cb);
319 goto out;
320 }
321
322 if (cl == &dev->iamthif_cl) {
323 rets = mei_amthif_write(cl, cb);
324 if (!rets)
325 rets = length;
326 goto out;
327 }
328
329 rets = mei_cl_write(cl, cb, false);
330out:
331 mutex_unlock(&dev->device_lock);
332 return rets;
333}
334
335/**
336 * mei_ioctl_connect_client - the connect to fw client IOCTL function
337 *
338 * @file: private data of the file object
339 * @data: IOCTL connect data, input and output parameters
340 *
341 * Locking: called under "dev->device_lock" lock
342 *
343 * Return: 0 on success, <0 on failure.
344 */
345static int mei_ioctl_connect_client(struct file *file,
346 struct mei_connect_client_data *data)
347{
348 struct mei_device *dev;
349 struct mei_client *client;
350 struct mei_me_client *me_cl;
351 struct mei_cl *cl;
352 int rets;
353
354 cl = file->private_data;
355 dev = cl->dev;
356
357 if (dev->dev_state != MEI_DEV_ENABLED)
358 return -ENODEV;
359
360 if (cl->state != MEI_FILE_INITIALIZING &&
361 cl->state != MEI_FILE_DISCONNECTED)
362 return -EBUSY;
363
364 /* find ME client we're trying to connect to */
365 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
366 if (!me_cl) {
367 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
368 &data->in_client_uuid);
369 rets = -ENOTTY;
370 goto end;
371 }
372
373 if (me_cl->props.fixed_address) {
374 bool forbidden = dev->override_fixed_address ?
375 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
376 if (forbidden) {
377 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
378 &data->in_client_uuid);
379 rets = -ENOTTY;
380 goto end;
381 }
382 }
383
384 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
385 me_cl->client_id);
386 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
387 me_cl->props.protocol_version);
388 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
389 me_cl->props.max_msg_length);
390
391 /* if we're connecting to amthif client then we will use the
392 * existing connection
393 */
394 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
395 dev_dbg(dev->dev, "FW Client is amthi\n");
396 if (!mei_cl_is_connected(&dev->iamthif_cl)) {
397 rets = -ENODEV;
398 goto end;
399 }
400 mei_cl_unlink(cl);
401
402 kfree(cl);
403 cl = NULL;
404 dev->iamthif_open_count++;
405 file->private_data = &dev->iamthif_cl;
406
407 client = &data->out_client_properties;
408 client->max_msg_length = me_cl->props.max_msg_length;
409 client->protocol_version = me_cl->props.protocol_version;
410 rets = dev->iamthif_cl.status;
411
412 goto end;
413 }
414
415 /* prepare the output buffer */
416 client = &data->out_client_properties;
417 client->max_msg_length = me_cl->props.max_msg_length;
418 client->protocol_version = me_cl->props.protocol_version;
419 dev_dbg(dev->dev, "Can connect?\n");
420
421 rets = mei_cl_connect(cl, me_cl, file);
422
423end:
424 mei_me_cl_put(me_cl);
425 return rets;
426}
427
428/**
429 * mei_ioctl_client_notify_request -
430 * propagate event notification request to client
431 *
432 * @file: pointer to file structure
433 * @request: 0 - disable, 1 - enable
434 *
435 * Return: 0 on success , <0 on error
436 */
437static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
438{
439 struct mei_cl *cl = file->private_data;
440
441 if (request != MEI_HBM_NOTIFICATION_START &&
442 request != MEI_HBM_NOTIFICATION_STOP)
443 return -EINVAL;
444
445 return mei_cl_notify_request(cl, file, (u8)request);
446}
447
448/**
449 * mei_ioctl_client_notify_get - wait for notification request
450 *
451 * @file: pointer to file structure
452 * @notify_get: 0 - disable, 1 - enable
453 *
454 * Return: 0 on success , <0 on error
455 */
456static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
457{
458 struct mei_cl *cl = file->private_data;
459 bool notify_ev;
460 bool block = (file->f_flags & O_NONBLOCK) == 0;
461 int rets;
462
463 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
464 if (rets)
465 return rets;
466
467 *notify_get = notify_ev ? 1 : 0;
468 return 0;
469}
470
471/**
472 * mei_ioctl - the IOCTL function
473 *
474 * @file: pointer to file structure
475 * @cmd: ioctl command
476 * @data: pointer to mei message structure
477 *
478 * Return: 0 on success , <0 on error
479 */
480static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
481{
482 struct mei_device *dev;
483 struct mei_cl *cl = file->private_data;
484 struct mei_connect_client_data connect_data;
485 u32 notify_get, notify_req;
486 int rets;
487
488
489 if (WARN_ON(!cl || !cl->dev))
490 return -ENODEV;
491
492 dev = cl->dev;
493
494 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
495
496 mutex_lock(&dev->device_lock);
497 if (dev->dev_state != MEI_DEV_ENABLED) {
498 rets = -ENODEV;
499 goto out;
500 }
501
502 switch (cmd) {
503 case IOCTL_MEI_CONNECT_CLIENT:
504 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
505 if (copy_from_user(&connect_data, (char __user *)data,
506 sizeof(struct mei_connect_client_data))) {
507 dev_dbg(dev->dev, "failed to copy data from userland\n");
508 rets = -EFAULT;
509 goto out;
510 }
511
512 rets = mei_ioctl_connect_client(file, &connect_data);
513 if (rets)
514 goto out;
515
516 /* if all is ok, copying the data back to user. */
517 if (copy_to_user((char __user *)data, &connect_data,
518 sizeof(struct mei_connect_client_data))) {
519 dev_dbg(dev->dev, "failed to copy data to userland\n");
520 rets = -EFAULT;
521 goto out;
522 }
523
524 break;
525
526 case IOCTL_MEI_NOTIFY_SET:
527 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
528 if (copy_from_user(¬ify_req,
529 (char __user *)data, sizeof(notify_req))) {
530 dev_dbg(dev->dev, "failed to copy data from userland\n");
531 rets = -EFAULT;
532 goto out;
533 }
534 rets = mei_ioctl_client_notify_request(file, notify_req);
535 break;
536
537 case IOCTL_MEI_NOTIFY_GET:
538 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
539 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
540 if (rets)
541 goto out;
542
543 dev_dbg(dev->dev, "copy connect data to user\n");
544 if (copy_to_user((char __user *)data,
545 ¬ify_get, sizeof(notify_get))) {
546 dev_dbg(dev->dev, "failed to copy data to userland\n");
547 rets = -EFAULT;
548 goto out;
549
550 }
551 break;
552
553 default:
554 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
555 rets = -ENOIOCTLCMD;
556 }
557
558out:
559 mutex_unlock(&dev->device_lock);
560 return rets;
561}
562
563/**
564 * mei_compat_ioctl - the compat IOCTL function
565 *
566 * @file: pointer to file structure
567 * @cmd: ioctl command
568 * @data: pointer to mei message structure
569 *
570 * Return: 0 on success , <0 on error
571 */
572#ifdef CONFIG_COMPAT
573static long mei_compat_ioctl(struct file *file,
574 unsigned int cmd, unsigned long data)
575{
576 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
577}
578#endif
579
580
581/**
582 * mei_poll - the poll function
583 *
584 * @file: pointer to file structure
585 * @wait: pointer to poll_table structure
586 *
587 * Return: poll mask
588 */
589static unsigned int mei_poll(struct file *file, poll_table *wait)
590{
591 unsigned long req_events = poll_requested_events(wait);
592 struct mei_cl *cl = file->private_data;
593 struct mei_device *dev;
594 unsigned int mask = 0;
595 bool notify_en;
596
597 if (WARN_ON(!cl || !cl->dev))
598 return POLLERR;
599
600 dev = cl->dev;
601
602 mutex_lock(&dev->device_lock);
603
604 notify_en = cl->notify_en && (req_events & POLLPRI);
605
606 if (dev->dev_state != MEI_DEV_ENABLED ||
607 !mei_cl_is_connected(cl)) {
608 mask = POLLERR;
609 goto out;
610 }
611
612 if (cl == &dev->iamthif_cl) {
613 mask = mei_amthif_poll(dev, file, wait);
614 goto out;
615 }
616
617 if (notify_en) {
618 poll_wait(file, &cl->ev_wait, wait);
619 if (cl->notify_ev)
620 mask |= POLLPRI;
621 }
622
623 if (req_events & (POLLIN | POLLRDNORM)) {
624 poll_wait(file, &cl->rx_wait, wait);
625
626 if (!list_empty(&cl->rd_completed))
627 mask |= POLLIN | POLLRDNORM;
628 else
629 mei_cl_read_start(cl, 0, file);
630 }
631
632out:
633 mutex_unlock(&dev->device_lock);
634 return mask;
635}
636
637/**
638 * mei_fasync - asynchronous io support
639 *
640 * @fd: file descriptor
641 * @file: pointer to file structure
642 * @band: band bitmap
643 *
644 * Return: negative on error,
645 * 0 if it did no changes,
646 * and positive a process was added or deleted
647 */
648static int mei_fasync(int fd, struct file *file, int band)
649{
650
651 struct mei_cl *cl = file->private_data;
652
653 if (!mei_cl_is_connected(cl))
654 return -ENODEV;
655
656 return fasync_helper(fd, file, band, &cl->ev_async);
657}
658
659/**
660 * fw_status_show - mei device attribute show method
661 *
662 * @device: device pointer
663 * @attr: attribute pointer
664 * @buf: char out buffer
665 *
666 * Return: number of the bytes printed into buf or error
667 */
668static ssize_t fw_status_show(struct device *device,
669 struct device_attribute *attr, char *buf)
670{
671 struct mei_device *dev = dev_get_drvdata(device);
672 struct mei_fw_status fw_status;
673 int err, i;
674 ssize_t cnt = 0;
675
676 mutex_lock(&dev->device_lock);
677 err = mei_fw_status(dev, &fw_status);
678 mutex_unlock(&dev->device_lock);
679 if (err) {
680 dev_err(device, "read fw_status error = %d\n", err);
681 return err;
682 }
683
684 for (i = 0; i < fw_status.count; i++)
685 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
686 fw_status.status[i]);
687 return cnt;
688}
689static DEVICE_ATTR_RO(fw_status);
690
691static struct attribute *mei_attrs[] = {
692 &dev_attr_fw_status.attr,
693 NULL
694};
695ATTRIBUTE_GROUPS(mei);
696
697/*
698 * file operations structure will be used for mei char device.
699 */
700static const struct file_operations mei_fops = {
701 .owner = THIS_MODULE,
702 .read = mei_read,
703 .unlocked_ioctl = mei_ioctl,
704#ifdef CONFIG_COMPAT
705 .compat_ioctl = mei_compat_ioctl,
706#endif
707 .open = mei_open,
708 .release = mei_release,
709 .write = mei_write,
710 .poll = mei_poll,
711 .fasync = mei_fasync,
712 .llseek = no_llseek
713};
714
715static struct class *mei_class;
716static dev_t mei_devt;
717#define MEI_MAX_DEVS MINORMASK
718static DEFINE_MUTEX(mei_minor_lock);
719static DEFINE_IDR(mei_idr);
720
721/**
722 * mei_minor_get - obtain next free device minor number
723 *
724 * @dev: device pointer
725 *
726 * Return: allocated minor, or -ENOSPC if no free minor left
727 */
728static int mei_minor_get(struct mei_device *dev)
729{
730 int ret;
731
732 mutex_lock(&mei_minor_lock);
733 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
734 if (ret >= 0)
735 dev->minor = ret;
736 else if (ret == -ENOSPC)
737 dev_err(dev->dev, "too many mei devices\n");
738
739 mutex_unlock(&mei_minor_lock);
740 return ret;
741}
742
743/**
744 * mei_minor_free - mark device minor number as free
745 *
746 * @dev: device pointer
747 */
748static void mei_minor_free(struct mei_device *dev)
749{
750 mutex_lock(&mei_minor_lock);
751 idr_remove(&mei_idr, dev->minor);
752 mutex_unlock(&mei_minor_lock);
753}
754
755int mei_register(struct mei_device *dev, struct device *parent)
756{
757 struct device *clsdev; /* class device */
758 int ret, devno;
759
760 ret = mei_minor_get(dev);
761 if (ret < 0)
762 return ret;
763
764 /* Fill in the data structures */
765 devno = MKDEV(MAJOR(mei_devt), dev->minor);
766 cdev_init(&dev->cdev, &mei_fops);
767 dev->cdev.owner = parent->driver->owner;
768
769 /* Add the device */
770 ret = cdev_add(&dev->cdev, devno, 1);
771 if (ret) {
772 dev_err(parent, "unable to add device %d:%d\n",
773 MAJOR(mei_devt), dev->minor);
774 goto err_dev_add;
775 }
776
777 clsdev = device_create_with_groups(mei_class, parent, devno,
778 dev, mei_groups,
779 "mei%d", dev->minor);
780
781 if (IS_ERR(clsdev)) {
782 dev_err(parent, "unable to create device %d:%d\n",
783 MAJOR(mei_devt), dev->minor);
784 ret = PTR_ERR(clsdev);
785 goto err_dev_create;
786 }
787
788 ret = mei_dbgfs_register(dev, dev_name(clsdev));
789 if (ret) {
790 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
791 goto err_dev_dbgfs;
792 }
793
794 return 0;
795
796err_dev_dbgfs:
797 device_destroy(mei_class, devno);
798err_dev_create:
799 cdev_del(&dev->cdev);
800err_dev_add:
801 mei_minor_free(dev);
802 return ret;
803}
804EXPORT_SYMBOL_GPL(mei_register);
805
806void mei_deregister(struct mei_device *dev)
807{
808 int devno;
809
810 devno = dev->cdev.dev;
811 cdev_del(&dev->cdev);
812
813 mei_dbgfs_deregister(dev);
814
815 device_destroy(mei_class, devno);
816
817 mei_minor_free(dev);
818}
819EXPORT_SYMBOL_GPL(mei_deregister);
820
821static int __init mei_init(void)
822{
823 int ret;
824
825 mei_class = class_create(THIS_MODULE, "mei");
826 if (IS_ERR(mei_class)) {
827 pr_err("couldn't create class\n");
828 ret = PTR_ERR(mei_class);
829 goto err;
830 }
831
832 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
833 if (ret < 0) {
834 pr_err("unable to allocate char dev region\n");
835 goto err_class;
836 }
837
838 ret = mei_cl_bus_init();
839 if (ret < 0) {
840 pr_err("unable to initialize bus\n");
841 goto err_chrdev;
842 }
843
844 return 0;
845
846err_chrdev:
847 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
848err_class:
849 class_destroy(mei_class);
850err:
851 return ret;
852}
853
854static void __exit mei_exit(void)
855{
856 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
857 class_destroy(mei_class);
858 mei_cl_bus_exit();
859}
860
861module_init(mei_init);
862module_exit(mei_exit);
863
864MODULE_AUTHOR("Intel Corporation");
865MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
866MODULE_LICENSE("GPL v2");
867