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/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>
35 #include <linux/mei.h>
41 * mei_open - the open function
43 * @inode: pointer to inode structure
44 * @file: pointer to file structure
46 * Return: 0 on success, <0 on error
48 static int mei_open(struct inode *inode, struct file *file)
50 struct mei_device *dev;
55 dev = container_of(inode->i_cdev, struct mei_device, cdev);
59 mutex_lock(&dev->device_lock);
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));
68 cl = mei_cl_alloc_linked(dev, MEI_HOST_CLIENT_ID_ANY);
74 file->private_data = cl;
76 mutex_unlock(&dev->device_lock);
78 return nonseekable_open(inode, file);
81 mutex_unlock(&dev->device_lock);
86 * mei_release - the release function
88 * @inode: pointer to inode structure
89 * @file: pointer to file structure
91 * Return: 0 on success, <0 on error
93 static int mei_release(struct inode *inode, struct file *file)
95 struct mei_cl *cl = file->private_data;
96 struct mei_device *dev;
99 if (WARN_ON(!cl || !cl->dev))
104 mutex_lock(&dev->device_lock);
105 if (cl == &dev->iamthif_cl) {
106 rets = mei_amthif_release(dev, file);
109 rets = mei_cl_disconnect(cl);
111 mei_cl_flush_queues(cl, file);
112 cl_dbg(dev, cl, "removing\n");
116 file->private_data = NULL;
120 mutex_unlock(&dev->device_lock);
126 * mei_read - the read function.
128 * @file: pointer to file structure
129 * @ubuf: pointer to user buffer
130 * @length: buffer length
131 * @offset: data offset in buffer
133 * Return: >=0 data length on success , <0 on error
135 static ssize_t mei_read(struct file *file, char __user *ubuf,
136 size_t length, loff_t *offset)
138 struct mei_cl *cl = file->private_data;
139 struct mei_device *dev;
140 struct mei_cl_cb *cb = NULL;
145 if (WARN_ON(!cl || !cl->dev))
151 mutex_lock(&dev->device_lock);
152 if (dev->dev_state != MEI_DEV_ENABLED) {
162 if (cl == &dev->iamthif_cl) {
163 rets = mei_amthif_read(dev, file, ubuf, length, offset);
167 cb = mei_cl_read_cb(cl, file);
170 if (cb->buf_idx > *offset)
172 /* offset is beyond buf_idx we have no more data return 0 */
173 if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
177 /* Offset needs to be cleaned for contiguous reads*/
178 if (cb->buf_idx == 0 && *offset > 0)
180 } else if (*offset > 0) {
184 err = mei_cl_read_start(cl, length, file);
185 if (err && err != -EBUSY) {
186 cl_dbg(dev, cl, "mei start read failure status = %d\n", err);
191 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
192 if (file->f_flags & O_NONBLOCK) {
197 mutex_unlock(&dev->device_lock);
199 if (wait_event_interruptible(cl->rx_wait,
200 (!list_empty(&cl->rd_completed)) ||
201 (!mei_cl_is_connected(cl)))) {
203 if (signal_pending(current))
208 mutex_lock(&dev->device_lock);
209 if (!mei_cl_is_connected(cl)) {
215 cb = mei_cl_read_cb(cl, file);
217 if (mei_cl_is_fixed_address(cl) && dev->allow_fixed_address) {
218 cb = mei_cl_read_cb(cl, NULL);
227 /* now copy the data to user space */
230 cl_dbg(dev, cl, "read operation failed %d\n", rets);
234 cl_dbg(dev, cl, "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 cl_dbg(dev, cl, "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_cl_cb *write_cb = NULL;
279 struct mei_device *dev;
280 unsigned long timeout = 0;
283 if (WARN_ON(!cl || !cl->dev))
288 mutex_lock(&dev->device_lock);
290 if (dev->dev_state != MEI_DEV_ENABLED) {
295 if (!mei_cl_is_connected(cl)) {
296 cl_err(dev, cl, "is not connected");
301 if (!mei_me_cl_is_active(cl->me_cl)) {
306 if (length > mei_cl_mtu(cl)) {
316 if (cl == &dev->iamthif_cl) {
317 write_cb = mei_amthif_find_read_list_entry(dev, file);
320 timeout = write_cb->read_time +
321 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
323 if (time_after(jiffies, timeout)) {
325 mei_io_cb_free(write_cb);
332 write_cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
338 rets = copy_from_user(write_cb->buf.data, ubuf, length);
340 dev_dbg(dev->dev, "failed to copy data from userland\n");
345 if (cl == &dev->iamthif_cl) {
346 rets = mei_amthif_write(cl, write_cb);
350 "amthif write failed with status = %d\n", rets);
353 mutex_unlock(&dev->device_lock);
357 rets = mei_cl_write(cl, write_cb, false);
359 mutex_unlock(&dev->device_lock);
361 mei_io_cb_free(write_cb);
366 * mei_ioctl_connect_client - the connect to fw client IOCTL function
368 * @file: private data of the file object
369 * @data: IOCTL connect data, input and output parameters
371 * Locking: called under "dev->device_lock" lock
373 * Return: 0 on success, <0 on failure.
375 static int mei_ioctl_connect_client(struct file *file,
376 struct mei_connect_client_data *data)
378 struct mei_device *dev;
379 struct mei_client *client;
380 struct mei_me_client *me_cl;
384 cl = file->private_data;
387 if (dev->dev_state != MEI_DEV_ENABLED)
390 if (cl->state != MEI_FILE_INITIALIZING &&
391 cl->state != MEI_FILE_DISCONNECTED)
394 /* find ME client we're trying to connect to */
395 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
397 (me_cl->props.fixed_address && !dev->allow_fixed_address)) {
398 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
399 &data->in_client_uuid);
400 mei_me_cl_put(me_cl);
404 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
406 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
407 me_cl->props.protocol_version);
408 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
409 me_cl->props.max_msg_length);
411 /* if we're connecting to amthif client then we will use the
412 * existing connection
414 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
415 dev_dbg(dev->dev, "FW Client is amthi\n");
416 if (!mei_cl_is_connected(&dev->iamthif_cl)) {
424 dev->iamthif_open_count++;
425 file->private_data = &dev->iamthif_cl;
427 client = &data->out_client_properties;
428 client->max_msg_length = me_cl->props.max_msg_length;
429 client->protocol_version = me_cl->props.protocol_version;
430 rets = dev->iamthif_cl.status;
435 /* prepare the output buffer */
436 client = &data->out_client_properties;
437 client->max_msg_length = me_cl->props.max_msg_length;
438 client->protocol_version = me_cl->props.protocol_version;
439 dev_dbg(dev->dev, "Can connect?\n");
441 rets = mei_cl_connect(cl, me_cl, file);
444 mei_me_cl_put(me_cl);
449 * mei_ioctl - the IOCTL function
451 * @file: pointer to file structure
452 * @cmd: ioctl command
453 * @data: pointer to mei message structure
455 * Return: 0 on success , <0 on error
457 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
459 struct mei_device *dev;
460 struct mei_cl *cl = file->private_data;
461 struct mei_connect_client_data connect_data;
465 if (WARN_ON(!cl || !cl->dev))
470 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
472 mutex_lock(&dev->device_lock);
473 if (dev->dev_state != MEI_DEV_ENABLED) {
479 case IOCTL_MEI_CONNECT_CLIENT:
480 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
481 if (copy_from_user(&connect_data, (char __user *)data,
482 sizeof(struct mei_connect_client_data))) {
483 dev_dbg(dev->dev, "failed to copy data from userland\n");
488 rets = mei_ioctl_connect_client(file, &connect_data);
492 /* if all is ok, copying the data back to user. */
493 if (copy_to_user((char __user *)data, &connect_data,
494 sizeof(struct mei_connect_client_data))) {
495 dev_dbg(dev->dev, "failed to copy data to userland\n");
503 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
508 mutex_unlock(&dev->device_lock);
513 * mei_compat_ioctl - the compat IOCTL function
515 * @file: pointer to file structure
516 * @cmd: ioctl command
517 * @data: pointer to mei message structure
519 * Return: 0 on success , <0 on error
522 static long mei_compat_ioctl(struct file *file,
523 unsigned int cmd, unsigned long data)
525 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
531 * mei_poll - the poll function
533 * @file: pointer to file structure
534 * @wait: pointer to poll_table structure
538 static unsigned int mei_poll(struct file *file, poll_table *wait)
540 unsigned long req_events = poll_requested_events(wait);
541 struct mei_cl *cl = file->private_data;
542 struct mei_device *dev;
543 unsigned int mask = 0;
545 if (WARN_ON(!cl || !cl->dev))
550 mutex_lock(&dev->device_lock);
553 if (dev->dev_state != MEI_DEV_ENABLED ||
554 !mei_cl_is_connected(cl)) {
559 if (cl == &dev->iamthif_cl) {
560 mask = mei_amthif_poll(dev, file, wait);
564 if (req_events & (POLLIN | POLLRDNORM)) {
565 poll_wait(file, &cl->rx_wait, wait);
567 if (!list_empty(&cl->rd_completed))
568 mask |= POLLIN | POLLRDNORM;
570 mei_cl_read_start(cl, 0, file);
574 mutex_unlock(&dev->device_lock);
579 * fw_status_show - mei device attribute show method
581 * @device: device pointer
582 * @attr: attribute pointer
583 * @buf: char out buffer
585 * Return: number of the bytes printed into buf or error
587 static ssize_t fw_status_show(struct device *device,
588 struct device_attribute *attr, char *buf)
590 struct mei_device *dev = dev_get_drvdata(device);
591 struct mei_fw_status fw_status;
595 mutex_lock(&dev->device_lock);
596 err = mei_fw_status(dev, &fw_status);
597 mutex_unlock(&dev->device_lock);
599 dev_err(device, "read fw_status error = %d\n", err);
603 for (i = 0; i < fw_status.count; i++)
604 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
605 fw_status.status[i]);
608 static DEVICE_ATTR_RO(fw_status);
610 static struct attribute *mei_attrs[] = {
611 &dev_attr_fw_status.attr,
614 ATTRIBUTE_GROUPS(mei);
617 * file operations structure will be used for mei char device.
619 static const struct file_operations mei_fops = {
620 .owner = THIS_MODULE,
622 .unlocked_ioctl = mei_ioctl,
624 .compat_ioctl = mei_compat_ioctl,
627 .release = mei_release,
633 static struct class *mei_class;
634 static dev_t mei_devt;
635 #define MEI_MAX_DEVS MINORMASK
636 static DEFINE_MUTEX(mei_minor_lock);
637 static DEFINE_IDR(mei_idr);
640 * mei_minor_get - obtain next free device minor number
642 * @dev: device pointer
644 * Return: allocated minor, or -ENOSPC if no free minor left
646 static int mei_minor_get(struct mei_device *dev)
650 mutex_lock(&mei_minor_lock);
651 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
654 else if (ret == -ENOSPC)
655 dev_err(dev->dev, "too many mei devices\n");
657 mutex_unlock(&mei_minor_lock);
662 * mei_minor_free - mark device minor number as free
664 * @dev: device pointer
666 static void mei_minor_free(struct mei_device *dev)
668 mutex_lock(&mei_minor_lock);
669 idr_remove(&mei_idr, dev->minor);
670 mutex_unlock(&mei_minor_lock);
673 int mei_register(struct mei_device *dev, struct device *parent)
675 struct device *clsdev; /* class device */
678 ret = mei_minor_get(dev);
682 /* Fill in the data structures */
683 devno = MKDEV(MAJOR(mei_devt), dev->minor);
684 cdev_init(&dev->cdev, &mei_fops);
685 dev->cdev.owner = parent->driver->owner;
688 ret = cdev_add(&dev->cdev, devno, 1);
690 dev_err(parent, "unable to add device %d:%d\n",
691 MAJOR(mei_devt), dev->minor);
695 clsdev = device_create_with_groups(mei_class, parent, devno,
697 "mei%d", dev->minor);
699 if (IS_ERR(clsdev)) {
700 dev_err(parent, "unable to create device %d:%d\n",
701 MAJOR(mei_devt), dev->minor);
702 ret = PTR_ERR(clsdev);
706 ret = mei_dbgfs_register(dev, dev_name(clsdev));
708 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
715 device_destroy(mei_class, devno);
717 cdev_del(&dev->cdev);
722 EXPORT_SYMBOL_GPL(mei_register);
724 void mei_deregister(struct mei_device *dev)
728 devno = dev->cdev.dev;
729 cdev_del(&dev->cdev);
731 mei_dbgfs_deregister(dev);
733 device_destroy(mei_class, devno);
737 EXPORT_SYMBOL_GPL(mei_deregister);
739 static int __init mei_init(void)
743 mei_class = class_create(THIS_MODULE, "mei");
744 if (IS_ERR(mei_class)) {
745 pr_err("couldn't create class\n");
746 ret = PTR_ERR(mei_class);
750 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
752 pr_err("unable to allocate char dev region\n");
756 ret = mei_cl_bus_init();
758 pr_err("unable to initialize bus\n");
765 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
767 class_destroy(mei_class);
772 static void __exit mei_exit(void)
774 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
775 class_destroy(mei_class);
779 module_init(mei_init);
780 module_exit(mei_exit);
782 MODULE_AUTHOR("Intel Corporation");
783 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
784 MODULE_LICENSE("GPL v2");