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);
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) {
167 if (cl == &dev->iamthif_cl) {
168 rets = mei_amthif_read(dev, file, ubuf, length, offset);
172 cb = mei_cl_read_cb(cl, file);
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);
186 /* synchronized under device mutex */
187 if (!waitqueue_active(&cl->rx_wait)) {
188 if (file->f_flags & O_NONBLOCK) {
193 mutex_unlock(&dev->device_lock);
195 if (wait_event_interruptible(cl->rx_wait,
196 (!list_empty(&cl->rd_completed)) ||
197 (!mei_cl_is_connected(cl)))) {
199 if (signal_pending(current))
204 mutex_lock(&dev->device_lock);
205 if (!mei_cl_is_connected(cl)) {
211 cb = mei_cl_read_cb(cl, file);
218 /* now copy the data to user space */
221 cl_dbg(dev, cl, "read operation failed %d\n", rets);
225 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
226 cb->buf.size, cb->buf_idx, *offset);
227 if (*offset >= cb->buf_idx) {
232 /* length is being truncated to PAGE_SIZE,
233 * however buf_idx may point beyond that */
234 length = min_t(size_t, length, cb->buf_idx - *offset);
236 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
237 dev_dbg(dev->dev, "failed to copy data to userland\n");
244 /* not all data was read, keep the cb */
245 if (*offset < cb->buf_idx)
253 cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
254 mutex_unlock(&dev->device_lock);
258 * mei_write - the write function.
260 * @file: pointer to file structure
261 * @ubuf: pointer to user buffer
262 * @length: buffer length
263 * @offset: data offset in buffer
265 * Return: >=0 data length on success , <0 on error
267 static ssize_t mei_write(struct file *file, const char __user *ubuf,
268 size_t length, loff_t *offset)
270 struct mei_cl *cl = file->private_data;
271 struct mei_cl_cb *cb;
272 struct mei_device *dev;
275 if (WARN_ON(!cl || !cl->dev))
280 mutex_lock(&dev->device_lock);
282 if (dev->dev_state != MEI_DEV_ENABLED) {
287 if (!mei_cl_is_connected(cl)) {
288 cl_err(dev, cl, "is not connected");
293 if (!mei_me_cl_is_active(cl->me_cl)) {
298 if (length > mei_cl_mtu(cl)) {
309 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
315 rets = copy_from_user(cb->buf.data, ubuf, length);
317 dev_dbg(dev->dev, "failed to copy data from userland\n");
323 if (cl == &dev->iamthif_cl) {
324 rets = mei_amthif_write(cl, cb);
330 rets = mei_cl_write(cl, cb, false);
332 mutex_unlock(&dev->device_lock);
337 * mei_ioctl_connect_client - the connect to fw client IOCTL function
339 * @file: private data of the file object
340 * @data: IOCTL connect data, input and output parameters
342 * Locking: called under "dev->device_lock" lock
344 * Return: 0 on success, <0 on failure.
346 static int mei_ioctl_connect_client(struct file *file,
347 struct mei_connect_client_data *data)
349 struct mei_device *dev;
350 struct mei_client *client;
351 struct mei_me_client *me_cl;
355 cl = file->private_data;
358 if (dev->dev_state != MEI_DEV_ENABLED)
361 if (cl->state != MEI_FILE_INITIALIZING &&
362 cl->state != MEI_FILE_DISCONNECTED)
365 /* find ME client we're trying to connect to */
366 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
368 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
369 &data->in_client_uuid);
374 if (me_cl->props.fixed_address) {
375 bool forbidden = dev->override_fixed_address ?
376 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
378 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
379 &data->in_client_uuid);
385 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
387 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
388 me_cl->props.protocol_version);
389 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
390 me_cl->props.max_msg_length);
392 /* if we're connecting to amthif client then we will use the
393 * existing connection
395 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
396 dev_dbg(dev->dev, "FW Client is amthi\n");
397 if (!mei_cl_is_connected(&dev->iamthif_cl)) {
405 dev->iamthif_open_count++;
406 file->private_data = &dev->iamthif_cl;
408 client = &data->out_client_properties;
409 client->max_msg_length = me_cl->props.max_msg_length;
410 client->protocol_version = me_cl->props.protocol_version;
411 rets = dev->iamthif_cl.status;
416 /* prepare the output buffer */
417 client = &data->out_client_properties;
418 client->max_msg_length = me_cl->props.max_msg_length;
419 client->protocol_version = me_cl->props.protocol_version;
420 dev_dbg(dev->dev, "Can connect?\n");
422 rets = mei_cl_connect(cl, me_cl, file);
425 mei_me_cl_put(me_cl);
430 * mei_ioctl_client_notify_request -
431 * propagate event notification request to client
433 * @file: pointer to file structure
434 * @request: 0 - disable, 1 - enable
436 * Return: 0 on success , <0 on error
438 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
440 struct mei_cl *cl = file->private_data;
442 if (request != MEI_HBM_NOTIFICATION_START &&
443 request != MEI_HBM_NOTIFICATION_STOP)
446 return mei_cl_notify_request(cl, file, (u8)request);
450 * mei_ioctl_client_notify_get - wait for notification request
452 * @file: pointer to file structure
453 * @notify_get: 0 - disable, 1 - enable
455 * Return: 0 on success , <0 on error
457 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
459 struct mei_cl *cl = file->private_data;
461 bool block = (file->f_flags & O_NONBLOCK) == 0;
464 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
468 *notify_get = notify_ev ? 1 : 0;
473 * mei_ioctl - the IOCTL function
475 * @file: pointer to file structure
476 * @cmd: ioctl command
477 * @data: pointer to mei message structure
479 * Return: 0 on success , <0 on error
481 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
483 struct mei_device *dev;
484 struct mei_cl *cl = file->private_data;
485 struct mei_connect_client_data connect_data;
486 u32 notify_get, notify_req;
490 if (WARN_ON(!cl || !cl->dev))
495 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
497 mutex_lock(&dev->device_lock);
498 if (dev->dev_state != MEI_DEV_ENABLED) {
504 case IOCTL_MEI_CONNECT_CLIENT:
505 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
506 if (copy_from_user(&connect_data, (char __user *)data,
507 sizeof(struct mei_connect_client_data))) {
508 dev_dbg(dev->dev, "failed to copy data from userland\n");
513 rets = mei_ioctl_connect_client(file, &connect_data);
517 /* if all is ok, copying the data back to user. */
518 if (copy_to_user((char __user *)data, &connect_data,
519 sizeof(struct mei_connect_client_data))) {
520 dev_dbg(dev->dev, "failed to copy data to userland\n");
527 case IOCTL_MEI_NOTIFY_SET:
528 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
529 if (copy_from_user(¬ify_req,
530 (char __user *)data, sizeof(notify_req))) {
531 dev_dbg(dev->dev, "failed to copy data from userland\n");
535 rets = mei_ioctl_client_notify_request(file, notify_req);
538 case IOCTL_MEI_NOTIFY_GET:
539 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
540 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
544 dev_dbg(dev->dev, "copy connect data to user\n");
545 if (copy_to_user((char __user *)data,
546 ¬ify_get, sizeof(notify_get))) {
547 dev_dbg(dev->dev, "failed to copy data to userland\n");
555 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
560 mutex_unlock(&dev->device_lock);
565 * mei_compat_ioctl - the compat IOCTL function
567 * @file: pointer to file structure
568 * @cmd: ioctl command
569 * @data: pointer to mei message structure
571 * Return: 0 on success , <0 on error
574 static long mei_compat_ioctl(struct file *file,
575 unsigned int cmd, unsigned long data)
577 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
583 * mei_poll - the poll function
585 * @file: pointer to file structure
586 * @wait: pointer to poll_table structure
590 static unsigned int mei_poll(struct file *file, poll_table *wait)
592 unsigned long req_events = poll_requested_events(wait);
593 struct mei_cl *cl = file->private_data;
594 struct mei_device *dev;
595 unsigned int mask = 0;
598 if (WARN_ON(!cl || !cl->dev))
603 mutex_lock(&dev->device_lock);
605 notify_en = cl->notify_en && (req_events & POLLPRI);
607 if (dev->dev_state != MEI_DEV_ENABLED ||
608 !mei_cl_is_connected(cl)) {
614 poll_wait(file, &cl->ev_wait, wait);
619 if (cl == &dev->iamthif_cl) {
620 mask |= mei_amthif_poll(file, wait);
624 if (req_events & (POLLIN | POLLRDNORM)) {
625 poll_wait(file, &cl->rx_wait, wait);
627 if (!list_empty(&cl->rd_completed))
628 mask |= POLLIN | POLLRDNORM;
630 mei_cl_read_start(cl, 0, file);
634 mutex_unlock(&dev->device_lock);
639 * mei_fasync - asynchronous io support
641 * @fd: file descriptor
642 * @file: pointer to file structure
645 * Return: negative on error,
646 * 0 if it did no changes,
647 * and positive a process was added or deleted
649 static int mei_fasync(int fd, struct file *file, int band)
652 struct mei_cl *cl = file->private_data;
654 if (!mei_cl_is_connected(cl))
657 return fasync_helper(fd, file, band, &cl->ev_async);
661 * fw_status_show - mei device attribute show method
663 * @device: device pointer
664 * @attr: attribute pointer
665 * @buf: char out buffer
667 * Return: number of the bytes printed into buf or error
669 static ssize_t fw_status_show(struct device *device,
670 struct device_attribute *attr, char *buf)
672 struct mei_device *dev = dev_get_drvdata(device);
673 struct mei_fw_status fw_status;
677 mutex_lock(&dev->device_lock);
678 err = mei_fw_status(dev, &fw_status);
679 mutex_unlock(&dev->device_lock);
681 dev_err(device, "read fw_status error = %d\n", err);
685 for (i = 0; i < fw_status.count; i++)
686 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
687 fw_status.status[i]);
690 static DEVICE_ATTR_RO(fw_status);
692 static struct attribute *mei_attrs[] = {
693 &dev_attr_fw_status.attr,
696 ATTRIBUTE_GROUPS(mei);
699 * file operations structure will be used for mei char device.
701 static const struct file_operations mei_fops = {
702 .owner = THIS_MODULE,
704 .unlocked_ioctl = mei_ioctl,
706 .compat_ioctl = mei_compat_ioctl,
709 .release = mei_release,
712 .fasync = mei_fasync,
716 static struct class *mei_class;
717 static dev_t mei_devt;
718 #define MEI_MAX_DEVS MINORMASK
719 static DEFINE_MUTEX(mei_minor_lock);
720 static DEFINE_IDR(mei_idr);
723 * mei_minor_get - obtain next free device minor number
725 * @dev: device pointer
727 * Return: allocated minor, or -ENOSPC if no free minor left
729 static int mei_minor_get(struct mei_device *dev)
733 mutex_lock(&mei_minor_lock);
734 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
737 else if (ret == -ENOSPC)
738 dev_err(dev->dev, "too many mei devices\n");
740 mutex_unlock(&mei_minor_lock);
745 * mei_minor_free - mark device minor number as free
747 * @dev: device pointer
749 static void mei_minor_free(struct mei_device *dev)
751 mutex_lock(&mei_minor_lock);
752 idr_remove(&mei_idr, dev->minor);
753 mutex_unlock(&mei_minor_lock);
756 int mei_register(struct mei_device *dev, struct device *parent)
758 struct device *clsdev; /* class device */
761 ret = mei_minor_get(dev);
765 /* Fill in the data structures */
766 devno = MKDEV(MAJOR(mei_devt), dev->minor);
767 cdev_init(&dev->cdev, &mei_fops);
768 dev->cdev.owner = parent->driver->owner;
771 ret = cdev_add(&dev->cdev, devno, 1);
773 dev_err(parent, "unable to add device %d:%d\n",
774 MAJOR(mei_devt), dev->minor);
778 clsdev = device_create_with_groups(mei_class, parent, devno,
780 "mei%d", dev->minor);
782 if (IS_ERR(clsdev)) {
783 dev_err(parent, "unable to create device %d:%d\n",
784 MAJOR(mei_devt), dev->minor);
785 ret = PTR_ERR(clsdev);
789 ret = mei_dbgfs_register(dev, dev_name(clsdev));
791 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
798 device_destroy(mei_class, devno);
800 cdev_del(&dev->cdev);
805 EXPORT_SYMBOL_GPL(mei_register);
807 void mei_deregister(struct mei_device *dev)
811 devno = dev->cdev.dev;
812 cdev_del(&dev->cdev);
814 mei_dbgfs_deregister(dev);
816 device_destroy(mei_class, devno);
820 EXPORT_SYMBOL_GPL(mei_deregister);
822 static int __init mei_init(void)
826 mei_class = class_create(THIS_MODULE, "mei");
827 if (IS_ERR(mei_class)) {
828 pr_err("couldn't create class\n");
829 ret = PTR_ERR(mei_class);
833 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
835 pr_err("unable to allocate char dev region\n");
839 ret = mei_cl_bus_init();
841 pr_err("unable to initialize bus\n");
848 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
850 class_destroy(mei_class);
855 static void __exit mei_exit(void)
857 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
858 class_destroy(mei_class);
862 module_init(mei_init);
863 module_exit(mei_exit);
865 MODULE_AUTHOR("Intel Corporation");
866 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
867 MODULE_LICENSE("GPL v2");