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
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/kernel.h>
22 #include <linux/device.h>
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/fcntl.h>
27 #include <linux/aio.h>
28 #include <linux/pci.h>
29 #include <linux/poll.h>
30 #include <linux/init.h>
31 #include <linux/ioctl.h>
32 #include <linux/cdev.h>
33 #include <linux/sched.h>
34 #include <linux/uuid.h>
35 #include <linux/compat.h>
36 #include <linux/jiffies.h>
37 #include <linux/interrupt.h>
38 #include <linux/miscdevice.h>
40 #include <linux/mei.h>
47 * mei_open - the open function
49 * @inode: pointer to inode structure
50 * @file: pointer to file structure
52 * returns 0 on success, <0 on error
54 static int mei_open(struct inode *inode, struct file *file)
56 struct miscdevice *misc = file->private_data;
59 struct mei_device *dev;
67 pdev = container_of(misc->parent, struct pci_dev, dev);
69 dev = pci_get_drvdata(pdev);
73 mutex_lock(&dev->device_lock);
75 cl = mei_cl_allocate(dev);
80 if (dev->dev_state != MEI_DEV_ENABLED) {
81 dev_dbg(&dev->pdev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
82 mei_dev_state_str(dev->dev_state));
86 if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
87 dev_err(&dev->pdev->dev, "open_handle_count exceded %d",
88 MEI_MAX_OPEN_HANDLE_COUNT);
92 err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
96 file->private_data = cl;
97 mutex_unlock(&dev->device_lock);
99 return nonseekable_open(inode, file);
102 mutex_unlock(&dev->device_lock);
109 * mei_release - the release function
111 * @inode: pointer to inode structure
112 * @file: pointer to file structure
114 * returns 0 on success, <0 on error
116 static int mei_release(struct inode *inode, struct file *file)
118 struct mei_cl *cl = file->private_data;
119 struct mei_cl_cb *cb;
120 struct mei_device *dev;
123 if (WARN_ON(!cl || !cl->dev))
128 mutex_lock(&dev->device_lock);
129 if (cl == &dev->iamthif_cl) {
130 rets = mei_amthif_release(dev, file);
133 if (cl->state == MEI_FILE_CONNECTED) {
134 cl->state = MEI_FILE_DISCONNECTING;
135 dev_dbg(&dev->pdev->dev,
136 "disconnecting client host client = %d, "
140 rets = mei_cl_disconnect(cl);
142 mei_cl_flush_queues(cl);
143 dev_dbg(&dev->pdev->dev, "remove client host client = %d, ME client = %d\n",
147 if (dev->open_handle_count > 0) {
148 clear_bit(cl->host_client_id, dev->host_clients_map);
149 dev->open_handle_count--;
157 cb = mei_cl_find_read_cb(cl);
158 /* Remove entry from read list */
166 file->private_data = NULL;
175 mutex_unlock(&dev->device_lock);
181 * mei_read - the read function.
183 * @file: pointer to file structure
184 * @ubuf: pointer to user buffer
185 * @length: buffer length
186 * @offset: data offset in buffer
188 * returns >=0 data length on success , <0 on error
190 static ssize_t mei_read(struct file *file, char __user *ubuf,
191 size_t length, loff_t *offset)
193 struct mei_cl *cl = file->private_data;
194 struct mei_cl_cb *cb_pos = NULL;
195 struct mei_cl_cb *cb = NULL;
196 struct mei_device *dev;
201 if (WARN_ON(!cl || !cl->dev))
206 mutex_lock(&dev->device_lock);
207 if (dev->dev_state != MEI_DEV_ENABLED) {
212 if (cl == &dev->iamthif_cl) {
213 rets = mei_amthif_read(dev, file, ubuf, length, offset);
220 if (cb->buf_idx > *offset)
222 /* offset is beyond buf_idx we have no more data return 0 */
223 if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
227 /* Offset needs to be cleaned for contiguous reads*/
228 if (cb->buf_idx == 0 && *offset > 0)
230 } else if (*offset > 0) {
234 err = mei_cl_read_start(cl, length);
235 if (err && err != -EBUSY) {
236 dev_dbg(&dev->pdev->dev,
237 "mei start read failure with status = %d\n", err);
242 if (MEI_READ_COMPLETE != cl->reading_state &&
243 !waitqueue_active(&cl->rx_wait)) {
244 if (file->f_flags & O_NONBLOCK) {
249 mutex_unlock(&dev->device_lock);
251 if (wait_event_interruptible(cl->rx_wait,
252 MEI_READ_COMPLETE == cl->reading_state ||
253 mei_cl_is_transitioning(cl))) {
255 if (signal_pending(current))
260 mutex_lock(&dev->device_lock);
261 if (mei_cl_is_transitioning(cl)) {
273 if (cl->reading_state != MEI_READ_COMPLETE) {
277 /* now copy the data to user space */
279 dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
280 cb->response_buffer.size, cb->buf_idx);
281 if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
286 /* length is being truncated to PAGE_SIZE,
287 * however buf_idx may point beyond that */
288 length = min_t(size_t, length, cb->buf_idx - *offset);
290 if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
297 if ((unsigned long)*offset < cb->buf_idx)
301 cb_pos = mei_cl_find_read_cb(cl);
302 /* Remove entry from read list */
304 list_del(&cb_pos->list);
306 cl->reading_state = MEI_IDLE;
309 dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
310 mutex_unlock(&dev->device_lock);
314 * mei_write - the write function.
316 * @file: pointer to file structure
317 * @ubuf: pointer to user buffer
318 * @length: buffer length
319 * @offset: data offset in buffer
321 * returns >=0 data length on success , <0 on error
323 static ssize_t mei_write(struct file *file, const char __user *ubuf,
324 size_t length, loff_t *offset)
326 struct mei_cl *cl = file->private_data;
327 struct mei_cl_cb *write_cb = NULL;
328 struct mei_device *dev;
329 unsigned long timeout = 0;
333 if (WARN_ON(!cl || !cl->dev))
338 mutex_lock(&dev->device_lock);
340 if (dev->dev_state != MEI_DEV_ENABLED) {
345 id = mei_me_cl_by_id(dev, cl->me_client_id);
350 if (length > dev->me_clients[id].props.max_msg_length || length <= 0) {
355 if (cl->state != MEI_FILE_CONNECTED) {
356 dev_err(&dev->pdev->dev, "host client = %d, is not connected to ME client = %d",
357 cl->host_client_id, cl->me_client_id);
361 if (cl == &dev->iamthif_cl) {
362 write_cb = mei_amthif_find_read_list_entry(dev, file);
365 timeout = write_cb->read_time +
366 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
368 if (time_after(jiffies, timeout) ||
369 cl->reading_state == MEI_READ_COMPLETE) {
371 list_del(&write_cb->list);
372 mei_io_cb_free(write_cb);
378 /* free entry used in read */
379 if (cl->reading_state == MEI_READ_COMPLETE) {
381 write_cb = mei_cl_find_read_cb(cl);
383 list_del(&write_cb->list);
384 mei_io_cb_free(write_cb);
386 cl->reading_state = MEI_IDLE;
389 } else if (cl->reading_state == MEI_IDLE)
393 write_cb = mei_io_cb_init(cl, file);
395 dev_err(&dev->pdev->dev, "write cb allocation failed\n");
399 rets = mei_io_cb_alloc_req_buf(write_cb, length);
403 rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
407 if (cl == &dev->iamthif_cl) {
408 rets = mei_amthif_write(dev, write_cb);
411 dev_err(&dev->pdev->dev,
412 "amthif write failed with status = %d\n", rets);
415 mutex_unlock(&dev->device_lock);
419 rets = mei_cl_write(cl, write_cb, false);
421 mutex_unlock(&dev->device_lock);
423 mei_io_cb_free(write_cb);
428 * mei_ioctl_connect_client - the connect to fw client IOCTL function
430 * @dev: the device structure
431 * @data: IOCTL connect data, input and output parameters
432 * @file: private data of the file object
434 * Locking: called under "dev->device_lock" lock
436 * returns 0 on success, <0 on failure.
438 static int mei_ioctl_connect_client(struct file *file,
439 struct mei_connect_client_data *data)
441 struct mei_device *dev;
442 struct mei_client *client;
447 cl = file->private_data;
448 if (WARN_ON(!cl || !cl->dev))
453 if (dev->dev_state != MEI_DEV_ENABLED) {
458 if (cl->state != MEI_FILE_INITIALIZING &&
459 cl->state != MEI_FILE_DISCONNECTED) {
464 /* find ME client we're trying to connect to */
465 i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
466 if (i < 0 || dev->me_clients[i].props.fixed_address) {
467 dev_dbg(&dev->pdev->dev, "Cannot connect to FW Client UUID = %pUl\n",
468 &data->in_client_uuid);
473 cl->me_client_id = dev->me_clients[i].client_id;
474 cl->state = MEI_FILE_CONNECTING;
476 dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
478 dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
479 dev->me_clients[i].props.protocol_version);
480 dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
481 dev->me_clients[i].props.max_msg_length);
483 /* if we're connecting to amthif client then we will use the
484 * existing connection
486 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
487 dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
488 if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
492 clear_bit(cl->host_client_id, dev->host_clients_map);
497 file->private_data = &dev->iamthif_cl;
499 client = &data->out_client_properties;
500 client->max_msg_length =
501 dev->me_clients[i].props.max_msg_length;
502 client->protocol_version =
503 dev->me_clients[i].props.protocol_version;
504 rets = dev->iamthif_cl.status;
510 /* prepare the output buffer */
511 client = &data->out_client_properties;
512 client->max_msg_length = dev->me_clients[i].props.max_msg_length;
513 client->protocol_version = dev->me_clients[i].props.protocol_version;
514 dev_dbg(&dev->pdev->dev, "Can connect?\n");
517 rets = mei_cl_connect(cl, file);
525 * mei_ioctl - the IOCTL function
527 * @file: pointer to file structure
528 * @cmd: ioctl command
529 * @data: pointer to mei message structure
531 * returns 0 on success , <0 on error
533 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
535 struct mei_device *dev;
536 struct mei_cl *cl = file->private_data;
537 struct mei_connect_client_data *connect_data = NULL;
540 if (cmd != IOCTL_MEI_CONNECT_CLIENT)
543 if (WARN_ON(!cl || !cl->dev))
548 dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);
550 mutex_lock(&dev->device_lock);
551 if (dev->dev_state != MEI_DEV_ENABLED) {
556 dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
558 connect_data = kzalloc(sizeof(struct mei_connect_client_data),
564 dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
565 if (copy_from_user(connect_data, (char __user *)data,
566 sizeof(struct mei_connect_client_data))) {
567 dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
572 rets = mei_ioctl_connect_client(file, connect_data);
574 /* if all is ok, copying the data back to user. */
578 dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
579 if (copy_to_user((char __user *)data, connect_data,
580 sizeof(struct mei_connect_client_data))) {
581 dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
588 mutex_unlock(&dev->device_lock);
593 * mei_compat_ioctl - the compat IOCTL function
595 * @file: pointer to file structure
596 * @cmd: ioctl command
597 * @data: pointer to mei message structure
599 * returns 0 on success , <0 on error
602 static long mei_compat_ioctl(struct file *file,
603 unsigned int cmd, unsigned long data)
605 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
611 * mei_poll - the poll function
613 * @file: pointer to file structure
614 * @wait: pointer to poll_table structure
618 static unsigned int mei_poll(struct file *file, poll_table *wait)
620 struct mei_cl *cl = file->private_data;
621 struct mei_device *dev;
622 unsigned int mask = 0;
624 if (WARN_ON(!cl || !cl->dev))
629 mutex_lock(&dev->device_lock);
631 if (!mei_cl_is_connected(cl)) {
636 mutex_unlock(&dev->device_lock);
639 if (cl == &dev->iamthif_cl)
640 return mei_amthif_poll(dev, file, wait);
642 poll_wait(file, &cl->tx_wait, wait);
644 mutex_lock(&dev->device_lock);
646 if (!mei_cl_is_connected(cl)) {
651 if (MEI_WRITE_COMPLETE == cl->writing_state)
652 mask |= (POLLIN | POLLRDNORM);
655 mutex_unlock(&dev->device_lock);
660 * file operations structure will be used for mei char device.
662 static const struct file_operations mei_fops = {
663 .owner = THIS_MODULE,
665 .unlocked_ioctl = mei_ioctl,
667 .compat_ioctl = mei_compat_ioctl,
670 .release = mei_release,
679 static struct miscdevice mei_misc_device = {
682 .minor = MISC_DYNAMIC_MINOR,
686 int mei_register(struct mei_device *dev)
689 mei_misc_device.parent = &dev->pdev->dev;
690 ret = misc_register(&mei_misc_device);
694 if (mei_dbgfs_register(dev, mei_misc_device.name))
695 dev_err(&dev->pdev->dev, "cannot register debugfs\n");
699 EXPORT_SYMBOL_GPL(mei_register);
701 void mei_deregister(struct mei_device *dev)
703 mei_dbgfs_deregister(dev);
704 misc_deregister(&mei_misc_device);
705 mei_misc_device.parent = NULL;
707 EXPORT_SYMBOL_GPL(mei_deregister);
709 static int __init mei_init(void)
711 return mei_cl_bus_init();
714 static void __exit mei_exit(void)
719 module_init(mei_init);
720 module_exit(mei_exit);
722 MODULE_AUTHOR("Intel Corporation");
723 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
724 MODULE_LICENSE("GPL v2");