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);
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 rets = mei_cl_disconnect(cl);
112 mei_cl_flush_queues(cl, file);
113 cl_dbg(dev, cl, "removing\n");
117 file->private_data = NULL;
121 mutex_unlock(&dev->device_lock);
127 * mei_read - the read function.
129 * @file: pointer to file structure
130 * @ubuf: pointer to user buffer
131 * @length: buffer length
132 * @offset: data offset in buffer
134 * Return: >=0 data length on success , <0 on error
136 static ssize_t mei_read(struct file *file, char __user *ubuf,
137 size_t length, loff_t *offset)
139 struct mei_cl *cl = file->private_data;
140 struct mei_device *dev;
141 struct mei_cl_cb *cb = NULL;
142 bool nonblock = !!(file->f_flags & O_NONBLOCK);
145 if (WARN_ON(!cl || !cl->dev))
151 mutex_lock(&dev->device_lock);
152 if (dev->dev_state != MEI_DEV_ENABLED) {
167 cb = mei_cl_read_cb(cl, file);
174 rets = mei_cl_read_start(cl, length, file);
175 if (rets && rets != -EBUSY) {
176 cl_dbg(dev, cl, "mei start read failure status = %d\n", rets);
187 mutex_unlock(&dev->device_lock);
188 if (wait_event_interruptible(cl->rx_wait,
189 !list_empty(&cl->rd_completed) ||
190 !mei_cl_is_connected(cl))) {
191 if (signal_pending(current))
195 mutex_lock(&dev->device_lock);
197 if (!mei_cl_is_connected(cl)) {
202 cb = mei_cl_read_cb(cl, file);
205 * For amthif all the waiters are woken up,
206 * but only fp with matching cb->fp get the cb,
207 * the others have to return to wait on read.
209 if (cl == &dev->iamthif_cl)
217 /* now copy the data to user space */
220 cl_dbg(dev, cl, "read operation failed %d\n", rets);
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) {
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);
235 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
236 dev_dbg(dev->dev, "failed to copy data to userland\n");
243 /* not all data was read, keep the cb */
244 if (*offset < cb->buf_idx)
252 cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
253 mutex_unlock(&dev->device_lock);
257 * mei_write - the write function.
259 * @file: pointer to file structure
260 * @ubuf: pointer to user buffer
261 * @length: buffer length
262 * @offset: data offset in buffer
264 * Return: >=0 data length on success , <0 on error
266 static ssize_t mei_write(struct file *file, const char __user *ubuf,
267 size_t length, loff_t *offset)
269 struct mei_cl *cl = file->private_data;
270 struct mei_cl_cb *cb;
271 struct mei_device *dev;
274 if (WARN_ON(!cl || !cl->dev))
279 mutex_lock(&dev->device_lock);
281 if (dev->dev_state != MEI_DEV_ENABLED) {
286 if (!mei_cl_is_connected(cl)) {
287 cl_err(dev, cl, "is not connected");
292 if (!mei_me_cl_is_active(cl->me_cl)) {
297 if (length > mei_cl_mtu(cl)) {
307 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
313 rets = copy_from_user(cb->buf.data, ubuf, length);
315 dev_dbg(dev->dev, "failed to copy data from userland\n");
321 if (cl == &dev->iamthif_cl) {
322 rets = mei_amthif_write(cl, cb);
328 rets = mei_cl_write(cl, cb, false);
330 mutex_unlock(&dev->device_lock);
335 * mei_ioctl_connect_client - the connect to fw client IOCTL function
337 * @file: private data of the file object
338 * @data: IOCTL connect data, input and output parameters
340 * Locking: called under "dev->device_lock" lock
342 * Return: 0 on success, <0 on failure.
344 static int mei_ioctl_connect_client(struct file *file,
345 struct mei_connect_client_data *data)
347 struct mei_device *dev;
348 struct mei_client *client;
349 struct mei_me_client *me_cl;
353 cl = file->private_data;
356 if (dev->dev_state != MEI_DEV_ENABLED)
359 if (cl->state != MEI_FILE_INITIALIZING &&
360 cl->state != MEI_FILE_DISCONNECTED)
363 /* find ME client we're trying to connect to */
364 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
366 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
367 &data->in_client_uuid);
372 if (me_cl->props.fixed_address) {
373 bool forbidden = dev->override_fixed_address ?
374 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
376 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
377 &data->in_client_uuid);
383 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
385 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
386 me_cl->props.protocol_version);
387 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
388 me_cl->props.max_msg_length);
390 /* if we're connecting to amthif client then we will use the
391 * existing connection
393 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
394 dev_dbg(dev->dev, "FW Client is amthi\n");
395 if (!mei_cl_is_connected(&dev->iamthif_cl)) {
403 dev->iamthif_open_count++;
404 file->private_data = &dev->iamthif_cl;
406 client = &data->out_client_properties;
407 client->max_msg_length = me_cl->props.max_msg_length;
408 client->protocol_version = me_cl->props.protocol_version;
409 rets = dev->iamthif_cl.status;
414 /* prepare the output buffer */
415 client = &data->out_client_properties;
416 client->max_msg_length = me_cl->props.max_msg_length;
417 client->protocol_version = me_cl->props.protocol_version;
418 dev_dbg(dev->dev, "Can connect?\n");
420 rets = mei_cl_connect(cl, me_cl, file);
423 mei_me_cl_put(me_cl);
428 * mei_ioctl_client_notify_request -
429 * propagate event notification request to client
431 * @file: pointer to file structure
432 * @request: 0 - disable, 1 - enable
434 * Return: 0 on success , <0 on error
436 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
438 struct mei_cl *cl = file->private_data;
440 if (request != MEI_HBM_NOTIFICATION_START &&
441 request != MEI_HBM_NOTIFICATION_STOP)
444 return mei_cl_notify_request(cl, file, (u8)request);
448 * mei_ioctl_client_notify_get - wait for notification request
450 * @file: pointer to file structure
451 * @notify_get: 0 - disable, 1 - enable
453 * Return: 0 on success , <0 on error
455 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
457 struct mei_cl *cl = file->private_data;
459 bool block = (file->f_flags & O_NONBLOCK) == 0;
462 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
466 *notify_get = notify_ev ? 1 : 0;
471 * mei_ioctl - the IOCTL function
473 * @file: pointer to file structure
474 * @cmd: ioctl command
475 * @data: pointer to mei message structure
477 * Return: 0 on success , <0 on error
479 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
481 struct mei_device *dev;
482 struct mei_cl *cl = file->private_data;
483 struct mei_connect_client_data connect_data;
484 u32 notify_get, notify_req;
488 if (WARN_ON(!cl || !cl->dev))
493 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
495 mutex_lock(&dev->device_lock);
496 if (dev->dev_state != MEI_DEV_ENABLED) {
502 case IOCTL_MEI_CONNECT_CLIENT:
503 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
504 if (copy_from_user(&connect_data, (char __user *)data,
505 sizeof(struct mei_connect_client_data))) {
506 dev_dbg(dev->dev, "failed to copy data from userland\n");
511 rets = mei_ioctl_connect_client(file, &connect_data);
515 /* if all is ok, copying the data back to user. */
516 if (copy_to_user((char __user *)data, &connect_data,
517 sizeof(struct mei_connect_client_data))) {
518 dev_dbg(dev->dev, "failed to copy data to userland\n");
525 case IOCTL_MEI_NOTIFY_SET:
526 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
527 if (copy_from_user(¬ify_req,
528 (char __user *)data, sizeof(notify_req))) {
529 dev_dbg(dev->dev, "failed to copy data from userland\n");
533 rets = mei_ioctl_client_notify_request(file, notify_req);
536 case IOCTL_MEI_NOTIFY_GET:
537 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
538 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
542 dev_dbg(dev->dev, "copy connect data to user\n");
543 if (copy_to_user((char __user *)data,
544 ¬ify_get, sizeof(notify_get))) {
545 dev_dbg(dev->dev, "failed to copy data to userland\n");
557 mutex_unlock(&dev->device_lock);
562 * mei_compat_ioctl - the compat IOCTL function
564 * @file: pointer to file structure
565 * @cmd: ioctl command
566 * @data: pointer to mei message structure
568 * Return: 0 on success , <0 on error
571 static long mei_compat_ioctl(struct file *file,
572 unsigned int cmd, unsigned long data)
574 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
580 * mei_poll - the poll function
582 * @file: pointer to file structure
583 * @wait: pointer to poll_table structure
587 static unsigned int mei_poll(struct file *file, poll_table *wait)
589 unsigned long req_events = poll_requested_events(wait);
590 struct mei_cl *cl = file->private_data;
591 struct mei_device *dev;
592 unsigned int mask = 0;
595 if (WARN_ON(!cl || !cl->dev))
600 mutex_lock(&dev->device_lock);
602 notify_en = cl->notify_en && (req_events & POLLPRI);
604 if (dev->dev_state != MEI_DEV_ENABLED ||
605 !mei_cl_is_connected(cl)) {
611 poll_wait(file, &cl->ev_wait, wait);
616 if (cl == &dev->iamthif_cl) {
617 mask |= mei_amthif_poll(file, wait);
621 if (req_events & (POLLIN | POLLRDNORM)) {
622 poll_wait(file, &cl->rx_wait, wait);
624 if (!list_empty(&cl->rd_completed))
625 mask |= POLLIN | POLLRDNORM;
627 mei_cl_read_start(cl, mei_cl_mtu(cl), file);
631 mutex_unlock(&dev->device_lock);
636 * mei_fasync - asynchronous io support
638 * @fd: file descriptor
639 * @file: pointer to file structure
642 * Return: negative on error,
643 * 0 if it did no changes,
644 * and positive a process was added or deleted
646 static int mei_fasync(int fd, struct file *file, int band)
649 struct mei_cl *cl = file->private_data;
651 if (!mei_cl_is_connected(cl))
654 return fasync_helper(fd, file, band, &cl->ev_async);
658 * fw_status_show - mei device attribute show method
660 * @device: device pointer
661 * @attr: attribute pointer
662 * @buf: char out buffer
664 * Return: number of the bytes printed into buf or error
666 static ssize_t fw_status_show(struct device *device,
667 struct device_attribute *attr, char *buf)
669 struct mei_device *dev = dev_get_drvdata(device);
670 struct mei_fw_status fw_status;
674 mutex_lock(&dev->device_lock);
675 err = mei_fw_status(dev, &fw_status);
676 mutex_unlock(&dev->device_lock);
678 dev_err(device, "read fw_status error = %d\n", err);
682 for (i = 0; i < fw_status.count; i++)
683 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
684 fw_status.status[i]);
687 static DEVICE_ATTR_RO(fw_status);
689 static struct attribute *mei_attrs[] = {
690 &dev_attr_fw_status.attr,
693 ATTRIBUTE_GROUPS(mei);
696 * file operations structure will be used for mei char device.
698 static const struct file_operations mei_fops = {
699 .owner = THIS_MODULE,
701 .unlocked_ioctl = mei_ioctl,
703 .compat_ioctl = mei_compat_ioctl,
706 .release = mei_release,
709 .fasync = mei_fasync,
713 static struct class *mei_class;
714 static dev_t mei_devt;
715 #define MEI_MAX_DEVS MINORMASK
716 static DEFINE_MUTEX(mei_minor_lock);
717 static DEFINE_IDR(mei_idr);
720 * mei_minor_get - obtain next free device minor number
722 * @dev: device pointer
724 * Return: allocated minor, or -ENOSPC if no free minor left
726 static int mei_minor_get(struct mei_device *dev)
730 mutex_lock(&mei_minor_lock);
731 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
734 else if (ret == -ENOSPC)
735 dev_err(dev->dev, "too many mei devices\n");
737 mutex_unlock(&mei_minor_lock);
742 * mei_minor_free - mark device minor number as free
744 * @dev: device pointer
746 static void mei_minor_free(struct mei_device *dev)
748 mutex_lock(&mei_minor_lock);
749 idr_remove(&mei_idr, dev->minor);
750 mutex_unlock(&mei_minor_lock);
753 int mei_register(struct mei_device *dev, struct device *parent)
755 struct device *clsdev; /* class device */
758 ret = mei_minor_get(dev);
762 /* Fill in the data structures */
763 devno = MKDEV(MAJOR(mei_devt), dev->minor);
764 cdev_init(&dev->cdev, &mei_fops);
765 dev->cdev.owner = parent->driver->owner;
768 ret = cdev_add(&dev->cdev, devno, 1);
770 dev_err(parent, "unable to add device %d:%d\n",
771 MAJOR(mei_devt), dev->minor);
775 clsdev = device_create_with_groups(mei_class, parent, devno,
777 "mei%d", dev->minor);
779 if (IS_ERR(clsdev)) {
780 dev_err(parent, "unable to create device %d:%d\n",
781 MAJOR(mei_devt), dev->minor);
782 ret = PTR_ERR(clsdev);
786 ret = mei_dbgfs_register(dev, dev_name(clsdev));
788 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
795 device_destroy(mei_class, devno);
797 cdev_del(&dev->cdev);
802 EXPORT_SYMBOL_GPL(mei_register);
804 void mei_deregister(struct mei_device *dev)
808 devno = dev->cdev.dev;
809 cdev_del(&dev->cdev);
811 mei_dbgfs_deregister(dev);
813 device_destroy(mei_class, devno);
817 EXPORT_SYMBOL_GPL(mei_deregister);
819 static int __init mei_init(void)
823 mei_class = class_create(THIS_MODULE, "mei");
824 if (IS_ERR(mei_class)) {
825 pr_err("couldn't create class\n");
826 ret = PTR_ERR(mei_class);
830 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
832 pr_err("unable to allocate char dev region\n");
836 ret = mei_cl_bus_init();
838 pr_err("unable to initialize bus\n");
845 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
847 class_destroy(mei_class);
852 static void __exit mei_exit(void)
854 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
855 class_destroy(mei_class);
859 module_init(mei_init);
860 module_exit(mei_exit);
862 MODULE_AUTHOR("Intel Corporation");
863 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
864 MODULE_LICENSE("GPL v2");