3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2012, Intel Corporation.
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.
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
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>
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/fcntl.h>
25 #include <linux/aio.h>
26 #include <linux/poll.h>
27 #include <linux/init.h>
28 #include <linux/ioctl.h>
29 #include <linux/cdev.h>
30 #include <linux/sched.h>
31 #include <linux/uuid.h>
32 #include <linux/compat.h>
33 #include <linux/jiffies.h>
34 #include <linux/interrupt.h>
36 #include <linux/mei.h>
42 * mei_open - the open function
44 * @inode: pointer to inode structure
45 * @file: pointer to file structure
47 * Return: 0 on success, <0 on error
49 static int mei_open(struct inode *inode, struct file *file)
51 struct mei_device *dev;
56 dev = container_of(inode->i_cdev, struct mei_device, cdev);
60 mutex_lock(&dev->device_lock);
62 if (dev->dev_state != MEI_DEV_ENABLED) {
63 dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
64 mei_dev_state_str(dev->dev_state));
69 cl = mei_cl_alloc_linked(dev, MEI_HOST_CLIENT_ID_ANY);
75 file->private_data = cl;
77 mutex_unlock(&dev->device_lock);
79 return nonseekable_open(inode, file);
82 mutex_unlock(&dev->device_lock);
87 * mei_release - the release function
89 * @inode: pointer to inode structure
90 * @file: pointer to file structure
92 * Return: 0 on success, <0 on error
94 static int mei_release(struct inode *inode, struct file *file)
96 struct mei_cl *cl = file->private_data;
97 struct mei_device *dev;
100 if (WARN_ON(!cl || !cl->dev))
105 mutex_lock(&dev->device_lock);
106 if (cl == &dev->iamthif_cl) {
107 rets = mei_amthif_release(dev, file);
110 if (cl->state == MEI_FILE_CONNECTED) {
111 cl->state = MEI_FILE_DISCONNECTING;
112 cl_dbg(dev, cl, "disconnecting\n");
113 rets = mei_cl_disconnect(cl);
115 mei_cl_flush_queues(cl, file);
116 cl_dbg(dev, cl, "removing\n");
120 file->private_data = NULL;
124 mutex_unlock(&dev->device_lock);
130 * mei_read - the read function.
132 * @file: pointer to file structure
133 * @ubuf: pointer to user buffer
134 * @length: buffer length
135 * @offset: data offset in buffer
137 * Return: >=0 data length on success , <0 on error
139 static ssize_t mei_read(struct file *file, char __user *ubuf,
140 size_t length, loff_t *offset)
142 struct mei_cl *cl = file->private_data;
143 struct mei_device *dev;
144 struct mei_cl_cb *cb = NULL;
149 if (WARN_ON(!cl || !cl->dev))
155 mutex_lock(&dev->device_lock);
156 if (dev->dev_state != MEI_DEV_ENABLED) {
166 if (cl == &dev->iamthif_cl) {
167 rets = mei_amthif_read(dev, file, ubuf, length, offset);
171 cb = mei_cl_read_cb(cl, file);
174 if (cb->buf_idx > *offset)
176 /* offset is beyond buf_idx we have no more data return 0 */
177 if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
181 /* Offset needs to be cleaned for contiguous reads*/
182 if (cb->buf_idx == 0 && *offset > 0)
184 } else if (*offset > 0) {
188 err = mei_cl_read_start(cl, length, file);
189 if (err && err != -EBUSY) {
191 "mei start read failure with status = %d\n", err);
196 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
197 if (file->f_flags & O_NONBLOCK) {
202 mutex_unlock(&dev->device_lock);
204 if (wait_event_interruptible(cl->rx_wait,
205 (!list_empty(&cl->rd_completed)) ||
206 mei_cl_is_transitioning(cl))) {
208 if (signal_pending(current))
213 mutex_lock(&dev->device_lock);
214 if (mei_cl_is_transitioning(cl)) {
220 cb = mei_cl_read_cb(cl, file);
227 /* now copy the data to user space */
230 dev_dbg(dev->dev, "read operation failed %d\n", rets);
234 dev_dbg(dev->dev, "buf.size = %d buf.idx= %ld\n",
235 cb->buf.size, cb->buf_idx);
236 if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
241 /* length is being truncated to PAGE_SIZE,
242 * however buf_idx may point beyond that */
243 length = min_t(size_t, length, cb->buf_idx - *offset);
245 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
246 dev_dbg(dev->dev, "failed to copy data to userland\n");
253 if ((unsigned long)*offset < cb->buf_idx)
260 dev_dbg(dev->dev, "end mei read rets= %d\n", rets);
261 mutex_unlock(&dev->device_lock);
265 * mei_write - the write function.
267 * @file: pointer to file structure
268 * @ubuf: pointer to user buffer
269 * @length: buffer length
270 * @offset: data offset in buffer
272 * Return: >=0 data length on success , <0 on error
274 static ssize_t mei_write(struct file *file, const char __user *ubuf,
275 size_t length, loff_t *offset)
277 struct mei_cl *cl = file->private_data;
278 struct mei_me_client *me_cl = NULL;
279 struct mei_cl_cb *write_cb = NULL;
280 struct mei_device *dev;
281 unsigned long timeout = 0;
284 if (WARN_ON(!cl || !cl->dev))
289 mutex_lock(&dev->device_lock);
291 if (dev->dev_state != MEI_DEV_ENABLED) {
296 me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);
307 if (length > me_cl->props.max_msg_length) {
312 if (cl->state != MEI_FILE_CONNECTED) {
313 dev_err(dev->dev, "host client = %d, is not connected to ME client = %d",
314 cl->host_client_id, cl->me_client_id);
318 if (cl == &dev->iamthif_cl) {
319 write_cb = mei_amthif_find_read_list_entry(dev, file);
322 timeout = write_cb->read_time +
323 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
325 if (time_after(jiffies, timeout)) {
327 mei_io_cb_free(write_cb);
334 write_cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
340 rets = copy_from_user(write_cb->buf.data, ubuf, length);
342 dev_dbg(dev->dev, "failed to copy data from userland\n");
347 if (cl == &dev->iamthif_cl) {
348 rets = mei_amthif_write(cl, write_cb);
352 "amthif write failed with status = %d\n", rets);
355 mei_me_cl_put(me_cl);
356 mutex_unlock(&dev->device_lock);
360 rets = mei_cl_write(cl, write_cb, false);
362 mei_me_cl_put(me_cl);
363 mutex_unlock(&dev->device_lock);
365 mei_io_cb_free(write_cb);
370 * mei_ioctl_connect_client - the connect to fw client IOCTL function
372 * @file: private data of the file object
373 * @data: IOCTL connect data, input and output parameters
375 * Locking: called under "dev->device_lock" lock
377 * Return: 0 on success, <0 on failure.
379 static int mei_ioctl_connect_client(struct file *file,
380 struct mei_connect_client_data *data)
382 struct mei_device *dev;
383 struct mei_client *client;
384 struct mei_me_client *me_cl;
388 cl = file->private_data;
391 if (dev->dev_state != MEI_DEV_ENABLED)
394 if (cl->state != MEI_FILE_INITIALIZING &&
395 cl->state != MEI_FILE_DISCONNECTED)
398 /* find ME client we're trying to connect to */
399 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
400 if (!me_cl || me_cl->props.fixed_address) {
401 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
402 &data->in_client_uuid);
406 cl->me_client_id = me_cl->client_id;
407 cl->cl_uuid = me_cl->props.protocol_name;
409 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
411 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
412 me_cl->props.protocol_version);
413 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
414 me_cl->props.max_msg_length);
416 /* if we're connecting to amthif client then we will use the
417 * existing connection
419 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
420 dev_dbg(dev->dev, "FW Client is amthi\n");
421 if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
429 dev->iamthif_open_count++;
430 file->private_data = &dev->iamthif_cl;
432 client = &data->out_client_properties;
433 client->max_msg_length = me_cl->props.max_msg_length;
434 client->protocol_version = me_cl->props.protocol_version;
435 rets = dev->iamthif_cl.status;
440 /* prepare the output buffer */
441 client = &data->out_client_properties;
442 client->max_msg_length = me_cl->props.max_msg_length;
443 client->protocol_version = me_cl->props.protocol_version;
444 dev_dbg(dev->dev, "Can connect?\n");
446 rets = mei_cl_connect(cl, file);
449 mei_me_cl_put(me_cl);
454 * mei_ioctl - the IOCTL function
456 * @file: pointer to file structure
457 * @cmd: ioctl command
458 * @data: pointer to mei message structure
460 * Return: 0 on success , <0 on error
462 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
464 struct mei_device *dev;
465 struct mei_cl *cl = file->private_data;
466 struct mei_connect_client_data connect_data;
470 if (WARN_ON(!cl || !cl->dev))
475 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
477 mutex_lock(&dev->device_lock);
478 if (dev->dev_state != MEI_DEV_ENABLED) {
484 case IOCTL_MEI_CONNECT_CLIENT:
485 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
486 if (copy_from_user(&connect_data, (char __user *)data,
487 sizeof(struct mei_connect_client_data))) {
488 dev_dbg(dev->dev, "failed to copy data from userland\n");
493 rets = mei_ioctl_connect_client(file, &connect_data);
497 /* if all is ok, copying the data back to user. */
498 if (copy_to_user((char __user *)data, &connect_data,
499 sizeof(struct mei_connect_client_data))) {
500 dev_dbg(dev->dev, "failed to copy data to userland\n");
508 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
513 mutex_unlock(&dev->device_lock);
518 * mei_compat_ioctl - the compat IOCTL function
520 * @file: pointer to file structure
521 * @cmd: ioctl command
522 * @data: pointer to mei message structure
524 * Return: 0 on success , <0 on error
527 static long mei_compat_ioctl(struct file *file,
528 unsigned int cmd, unsigned long data)
530 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
536 * mei_poll - the poll function
538 * @file: pointer to file structure
539 * @wait: pointer to poll_table structure
543 static unsigned int mei_poll(struct file *file, poll_table *wait)
545 unsigned long req_events = poll_requested_events(wait);
546 struct mei_cl *cl = file->private_data;
547 struct mei_device *dev;
548 unsigned int mask = 0;
550 if (WARN_ON(!cl || !cl->dev))
555 mutex_lock(&dev->device_lock);
557 if (!mei_cl_is_connected(cl)) {
562 if (cl == &dev->iamthif_cl) {
563 mask = mei_amthif_poll(dev, file, wait);
567 if (req_events & (POLLIN | POLLRDNORM)) {
568 poll_wait(file, &cl->rx_wait, wait);
570 if (!list_empty(&cl->rd_completed))
571 mask |= POLLIN | POLLRDNORM;
573 mei_cl_read_start(cl, 0, file);
577 mutex_unlock(&dev->device_lock);
582 * fw_status_show - mei device attribute show method
584 * @device: device pointer
585 * @attr: attribute pointer
586 * @buf: char out buffer
588 * Return: number of the bytes printed into buf or error
590 static ssize_t fw_status_show(struct device *device,
591 struct device_attribute *attr, char *buf)
593 struct mei_device *dev = dev_get_drvdata(device);
594 struct mei_fw_status fw_status;
598 mutex_lock(&dev->device_lock);
599 err = mei_fw_status(dev, &fw_status);
600 mutex_unlock(&dev->device_lock);
602 dev_err(device, "read fw_status error = %d\n", err);
606 for (i = 0; i < fw_status.count; i++)
607 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
608 fw_status.status[i]);
611 static DEVICE_ATTR_RO(fw_status);
613 static struct attribute *mei_attrs[] = {
614 &dev_attr_fw_status.attr,
617 ATTRIBUTE_GROUPS(mei);
620 * file operations structure will be used for mei char device.
622 static const struct file_operations mei_fops = {
623 .owner = THIS_MODULE,
625 .unlocked_ioctl = mei_ioctl,
627 .compat_ioctl = mei_compat_ioctl,
630 .release = mei_release,
636 static struct class *mei_class;
637 static dev_t mei_devt;
638 #define MEI_MAX_DEVS MINORMASK
639 static DEFINE_MUTEX(mei_minor_lock);
640 static DEFINE_IDR(mei_idr);
643 * mei_minor_get - obtain next free device minor number
645 * @dev: device pointer
647 * Return: allocated minor, or -ENOSPC if no free minor left
649 static int mei_minor_get(struct mei_device *dev)
653 mutex_lock(&mei_minor_lock);
654 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
657 else if (ret == -ENOSPC)
658 dev_err(dev->dev, "too many mei devices\n");
660 mutex_unlock(&mei_minor_lock);
665 * mei_minor_free - mark device minor number as free
667 * @dev: device pointer
669 static void mei_minor_free(struct mei_device *dev)
671 mutex_lock(&mei_minor_lock);
672 idr_remove(&mei_idr, dev->minor);
673 mutex_unlock(&mei_minor_lock);
676 int mei_register(struct mei_device *dev, struct device *parent)
678 struct device *clsdev; /* class device */
681 ret = mei_minor_get(dev);
685 /* Fill in the data structures */
686 devno = MKDEV(MAJOR(mei_devt), dev->minor);
687 cdev_init(&dev->cdev, &mei_fops);
688 dev->cdev.owner = mei_fops.owner;
691 ret = cdev_add(&dev->cdev, devno, 1);
693 dev_err(parent, "unable to add device %d:%d\n",
694 MAJOR(mei_devt), dev->minor);
698 clsdev = device_create_with_groups(mei_class, parent, devno,
700 "mei%d", dev->minor);
702 if (IS_ERR(clsdev)) {
703 dev_err(parent, "unable to create device %d:%d\n",
704 MAJOR(mei_devt), dev->minor);
705 ret = PTR_ERR(clsdev);
709 ret = mei_dbgfs_register(dev, dev_name(clsdev));
711 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
718 device_destroy(mei_class, devno);
720 cdev_del(&dev->cdev);
725 EXPORT_SYMBOL_GPL(mei_register);
727 void mei_deregister(struct mei_device *dev)
731 devno = dev->cdev.dev;
732 cdev_del(&dev->cdev);
734 mei_dbgfs_deregister(dev);
736 device_destroy(mei_class, devno);
740 EXPORT_SYMBOL_GPL(mei_deregister);
742 static int __init mei_init(void)
746 mei_class = class_create(THIS_MODULE, "mei");
747 if (IS_ERR(mei_class)) {
748 pr_err("couldn't create class\n");
749 ret = PTR_ERR(mei_class);
753 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
755 pr_err("unable to allocate char dev region\n");
759 ret = mei_cl_bus_init();
761 pr_err("unable to initialize bus\n");
768 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
770 class_destroy(mei_class);
775 static void __exit mei_exit(void)
777 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
778 class_destroy(mei_class);
782 module_init(mei_init);
783 module_exit(mei_exit);
785 MODULE_AUTHOR("Intel Corporation");
786 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
787 MODULE_LICENSE("GPL v2");