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;
146 if (WARN_ON(!cl || !cl->dev))
152 mutex_lock(&dev->device_lock);
153 if (dev->dev_state != MEI_DEV_ENABLED) {
168 if (cl == &dev->iamthif_cl) {
169 rets = mei_amthif_read(dev, file, ubuf, length, offset);
173 cb = mei_cl_read_cb(cl, file);
180 err = mei_cl_read_start(cl, length, file);
181 if (err && err != -EBUSY) {
182 cl_dbg(dev, cl, "mei start read failure status = %d\n", err);
187 /* synchronized under device mutex */
188 if (!waitqueue_active(&cl->rx_wait)) {
189 if (file->f_flags & O_NONBLOCK) {
194 mutex_unlock(&dev->device_lock);
196 if (wait_event_interruptible(cl->rx_wait,
197 (!list_empty(&cl->rd_completed)) ||
198 (!mei_cl_is_connected(cl)))) {
200 if (signal_pending(current))
205 mutex_lock(&dev->device_lock);
206 if (!mei_cl_is_connected(cl)) {
212 cb = mei_cl_read_cb(cl, file);
219 /* now copy the data to user space */
222 cl_dbg(dev, cl, "read operation failed %d\n", rets);
226 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
227 cb->buf.size, cb->buf_idx, *offset);
228 if (*offset >= cb->buf_idx) {
233 /* length is being truncated to PAGE_SIZE,
234 * however buf_idx may point beyond that */
235 length = min_t(size_t, length, cb->buf_idx - *offset);
237 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
238 dev_dbg(dev->dev, "failed to copy data to userland\n");
245 /* not all data was read, keep the cb */
246 if (*offset < cb->buf_idx)
254 cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
255 mutex_unlock(&dev->device_lock);
259 * mei_write - the write function.
261 * @file: pointer to file structure
262 * @ubuf: pointer to user buffer
263 * @length: buffer length
264 * @offset: data offset in buffer
266 * Return: >=0 data length on success , <0 on error
268 static ssize_t mei_write(struct file *file, const char __user *ubuf,
269 size_t length, loff_t *offset)
271 struct mei_cl *cl = file->private_data;
272 struct mei_cl_cb *cb;
273 struct mei_device *dev;
276 if (WARN_ON(!cl || !cl->dev))
281 mutex_lock(&dev->device_lock);
283 if (dev->dev_state != MEI_DEV_ENABLED) {
288 if (!mei_cl_is_connected(cl)) {
289 cl_err(dev, cl, "is not connected");
294 if (!mei_me_cl_is_active(cl->me_cl)) {
299 if (length > mei_cl_mtu(cl)) {
310 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
316 rets = copy_from_user(cb->buf.data, ubuf, length);
318 dev_dbg(dev->dev, "failed to copy data from userland\n");
324 if (cl == &dev->iamthif_cl) {
325 rets = mei_amthif_write(cl, cb);
331 rets = mei_cl_write(cl, cb, false);
333 mutex_unlock(&dev->device_lock);
338 * mei_ioctl_connect_client - the connect to fw client IOCTL function
340 * @file: private data of the file object
341 * @data: IOCTL connect data, input and output parameters
343 * Locking: called under "dev->device_lock" lock
345 * Return: 0 on success, <0 on failure.
347 static int mei_ioctl_connect_client(struct file *file,
348 struct mei_connect_client_data *data)
350 struct mei_device *dev;
351 struct mei_client *client;
352 struct mei_me_client *me_cl;
356 cl = file->private_data;
359 if (dev->dev_state != MEI_DEV_ENABLED)
362 if (cl->state != MEI_FILE_INITIALIZING &&
363 cl->state != MEI_FILE_DISCONNECTED)
366 /* find ME client we're trying to connect to */
367 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
369 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
370 &data->in_client_uuid);
375 if (me_cl->props.fixed_address) {
376 bool forbidden = dev->override_fixed_address ?
377 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
379 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
380 &data->in_client_uuid);
386 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
388 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
389 me_cl->props.protocol_version);
390 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
391 me_cl->props.max_msg_length);
393 /* if we're connecting to amthif client then we will use the
394 * existing connection
396 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
397 dev_dbg(dev->dev, "FW Client is amthi\n");
398 if (!mei_cl_is_connected(&dev->iamthif_cl)) {
406 dev->iamthif_open_count++;
407 file->private_data = &dev->iamthif_cl;
409 client = &data->out_client_properties;
410 client->max_msg_length = me_cl->props.max_msg_length;
411 client->protocol_version = me_cl->props.protocol_version;
412 rets = dev->iamthif_cl.status;
417 /* prepare the output buffer */
418 client = &data->out_client_properties;
419 client->max_msg_length = me_cl->props.max_msg_length;
420 client->protocol_version = me_cl->props.protocol_version;
421 dev_dbg(dev->dev, "Can connect?\n");
423 rets = mei_cl_connect(cl, me_cl, file);
426 mei_me_cl_put(me_cl);
431 * mei_ioctl_client_notify_request -
432 * propagate event notification request to client
434 * @file: pointer to file structure
435 * @request: 0 - disable, 1 - enable
437 * Return: 0 on success , <0 on error
439 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
441 struct mei_cl *cl = file->private_data;
443 if (request != MEI_HBM_NOTIFICATION_START &&
444 request != MEI_HBM_NOTIFICATION_STOP)
447 return mei_cl_notify_request(cl, file, (u8)request);
451 * mei_ioctl_client_notify_get - wait for notification request
453 * @file: pointer to file structure
454 * @notify_get: 0 - disable, 1 - enable
456 * Return: 0 on success , <0 on error
458 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
460 struct mei_cl *cl = file->private_data;
462 bool block = (file->f_flags & O_NONBLOCK) == 0;
465 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
469 *notify_get = notify_ev ? 1 : 0;
474 * mei_ioctl - the IOCTL function
476 * @file: pointer to file structure
477 * @cmd: ioctl command
478 * @data: pointer to mei message structure
480 * Return: 0 on success , <0 on error
482 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
484 struct mei_device *dev;
485 struct mei_cl *cl = file->private_data;
486 struct mei_connect_client_data connect_data;
487 u32 notify_get, notify_req;
491 if (WARN_ON(!cl || !cl->dev))
496 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
498 mutex_lock(&dev->device_lock);
499 if (dev->dev_state != MEI_DEV_ENABLED) {
505 case IOCTL_MEI_CONNECT_CLIENT:
506 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
507 if (copy_from_user(&connect_data, (char __user *)data,
508 sizeof(struct mei_connect_client_data))) {
509 dev_dbg(dev->dev, "failed to copy data from userland\n");
514 rets = mei_ioctl_connect_client(file, &connect_data);
518 /* if all is ok, copying the data back to user. */
519 if (copy_to_user((char __user *)data, &connect_data,
520 sizeof(struct mei_connect_client_data))) {
521 dev_dbg(dev->dev, "failed to copy data to userland\n");
528 case IOCTL_MEI_NOTIFY_SET:
529 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
530 if (copy_from_user(¬ify_req,
531 (char __user *)data, sizeof(notify_req))) {
532 dev_dbg(dev->dev, "failed to copy data from userland\n");
536 rets = mei_ioctl_client_notify_request(file, notify_req);
539 case IOCTL_MEI_NOTIFY_GET:
540 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
541 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
545 dev_dbg(dev->dev, "copy connect data to user\n");
546 if (copy_to_user((char __user *)data,
547 ¬ify_get, sizeof(notify_get))) {
548 dev_dbg(dev->dev, "failed to copy data to userland\n");
556 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
561 mutex_unlock(&dev->device_lock);
566 * mei_compat_ioctl - the compat IOCTL function
568 * @file: pointer to file structure
569 * @cmd: ioctl command
570 * @data: pointer to mei message structure
572 * Return: 0 on success , <0 on error
575 static long mei_compat_ioctl(struct file *file,
576 unsigned int cmd, unsigned long data)
578 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
584 * mei_poll - the poll function
586 * @file: pointer to file structure
587 * @wait: pointer to poll_table structure
591 static unsigned int mei_poll(struct file *file, poll_table *wait)
593 unsigned long req_events = poll_requested_events(wait);
594 struct mei_cl *cl = file->private_data;
595 struct mei_device *dev;
596 unsigned int mask = 0;
599 if (WARN_ON(!cl || !cl->dev))
604 mutex_lock(&dev->device_lock);
606 notify_en = cl->notify_en && (req_events & POLLPRI);
608 if (dev->dev_state != MEI_DEV_ENABLED ||
609 !mei_cl_is_connected(cl)) {
615 poll_wait(file, &cl->ev_wait, wait);
620 if (cl == &dev->iamthif_cl) {
621 mask |= mei_amthif_poll(file, wait);
625 if (req_events & (POLLIN | POLLRDNORM)) {
626 poll_wait(file, &cl->rx_wait, wait);
628 if (!list_empty(&cl->rd_completed))
629 mask |= POLLIN | POLLRDNORM;
631 mei_cl_read_start(cl, 0, file);
635 mutex_unlock(&dev->device_lock);
640 * mei_fasync - asynchronous io support
642 * @fd: file descriptor
643 * @file: pointer to file structure
646 * Return: negative on error,
647 * 0 if it did no changes,
648 * and positive a process was added or deleted
650 static int mei_fasync(int fd, struct file *file, int band)
653 struct mei_cl *cl = file->private_data;
655 if (!mei_cl_is_connected(cl))
658 return fasync_helper(fd, file, band, &cl->ev_async);
662 * fw_status_show - mei device attribute show method
664 * @device: device pointer
665 * @attr: attribute pointer
666 * @buf: char out buffer
668 * Return: number of the bytes printed into buf or error
670 static ssize_t fw_status_show(struct device *device,
671 struct device_attribute *attr, char *buf)
673 struct mei_device *dev = dev_get_drvdata(device);
674 struct mei_fw_status fw_status;
678 mutex_lock(&dev->device_lock);
679 err = mei_fw_status(dev, &fw_status);
680 mutex_unlock(&dev->device_lock);
682 dev_err(device, "read fw_status error = %d\n", err);
686 for (i = 0; i < fw_status.count; i++)
687 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
688 fw_status.status[i]);
691 static DEVICE_ATTR_RO(fw_status);
693 static struct attribute *mei_attrs[] = {
694 &dev_attr_fw_status.attr,
697 ATTRIBUTE_GROUPS(mei);
700 * file operations structure will be used for mei char device.
702 static const struct file_operations mei_fops = {
703 .owner = THIS_MODULE,
705 .unlocked_ioctl = mei_ioctl,
707 .compat_ioctl = mei_compat_ioctl,
710 .release = mei_release,
713 .fasync = mei_fasync,
717 static struct class *mei_class;
718 static dev_t mei_devt;
719 #define MEI_MAX_DEVS MINORMASK
720 static DEFINE_MUTEX(mei_minor_lock);
721 static DEFINE_IDR(mei_idr);
724 * mei_minor_get - obtain next free device minor number
726 * @dev: device pointer
728 * Return: allocated minor, or -ENOSPC if no free minor left
730 static int mei_minor_get(struct mei_device *dev)
734 mutex_lock(&mei_minor_lock);
735 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
738 else if (ret == -ENOSPC)
739 dev_err(dev->dev, "too many mei devices\n");
741 mutex_unlock(&mei_minor_lock);
746 * mei_minor_free - mark device minor number as free
748 * @dev: device pointer
750 static void mei_minor_free(struct mei_device *dev)
752 mutex_lock(&mei_minor_lock);
753 idr_remove(&mei_idr, dev->minor);
754 mutex_unlock(&mei_minor_lock);
757 int mei_register(struct mei_device *dev, struct device *parent)
759 struct device *clsdev; /* class device */
762 ret = mei_minor_get(dev);
766 /* Fill in the data structures */
767 devno = MKDEV(MAJOR(mei_devt), dev->minor);
768 cdev_init(&dev->cdev, &mei_fops);
769 dev->cdev.owner = parent->driver->owner;
772 ret = cdev_add(&dev->cdev, devno, 1);
774 dev_err(parent, "unable to add device %d:%d\n",
775 MAJOR(mei_devt), dev->minor);
779 clsdev = device_create_with_groups(mei_class, parent, devno,
781 "mei%d", dev->minor);
783 if (IS_ERR(clsdev)) {
784 dev_err(parent, "unable to create device %d:%d\n",
785 MAJOR(mei_devt), dev->minor);
786 ret = PTR_ERR(clsdev);
790 ret = mei_dbgfs_register(dev, dev_name(clsdev));
792 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
799 device_destroy(mei_class, devno);
801 cdev_del(&dev->cdev);
806 EXPORT_SYMBOL_GPL(mei_register);
808 void mei_deregister(struct mei_device *dev)
812 devno = dev->cdev.dev;
813 cdev_del(&dev->cdev);
815 mei_dbgfs_deregister(dev);
817 device_destroy(mei_class, devno);
821 EXPORT_SYMBOL_GPL(mei_deregister);
823 static int __init mei_init(void)
827 mei_class = class_create(THIS_MODULE, "mei");
828 if (IS_ERR(mei_class)) {
829 pr_err("couldn't create class\n");
830 ret = PTR_ERR(mei_class);
834 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
836 pr_err("unable to allocate char dev region\n");
840 ret = mei_cl_bus_init();
842 pr_err("unable to initialize bus\n");
849 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
851 class_destroy(mei_class);
856 static void __exit mei_exit(void)
858 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
859 class_destroy(mei_class);
863 module_init(mei_init);
864 module_exit(mei_exit);
866 MODULE_AUTHOR("Intel Corporation");
867 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
868 MODULE_LICENSE("GPL v2");