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>
21 #include <linux/errno.h>
22 #include <linux/types.h>
23 #include <linux/fcntl.h>
24 #include <linux/aio.h>
25 #include <linux/pci.h>
26 #include <linux/poll.h>
27 #include <linux/init.h>
28 #include <linux/ioctl.h>
29 #include <linux/cdev.h>
30 #include <linux/sched.h>
31 #include <linux/uuid.h>
32 #include <linux/compat.h>
33 #include <linux/jiffies.h>
34 #include <linux/interrupt.h>
35 #include <linux/miscdevice.h>
37 #include <linux/mei.h>
43 * mei_open - the open function
45 * @inode: pointer to inode structure
46 * @file: pointer to file structure
48 * returns 0 on success, <0 on error
50 static int mei_open(struct inode *inode, struct file *file)
52 struct miscdevice *misc = file->private_data;
55 struct mei_device *dev;
62 pdev = container_of(misc->parent, struct pci_dev, dev);
64 dev = pci_get_drvdata(pdev);
68 mutex_lock(&dev->device_lock);
73 if (dev->dev_state != MEI_DEV_ENABLED) {
74 dev_dbg(&dev->pdev->dev, "dev_state != MEI_ENABLED dev_state = %s\n",
75 mei_dev_state_str(dev->dev_state));
80 cl = mei_cl_allocate(dev);
84 /* open_handle_count check is handled in the mei_cl_link */
85 err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
89 file->private_data = cl;
91 mutex_unlock(&dev->device_lock);
93 return nonseekable_open(inode, file);
96 mutex_unlock(&dev->device_lock);
102 * mei_release - the release function
104 * @inode: pointer to inode structure
105 * @file: pointer to file structure
107 * returns 0 on success, <0 on error
109 static int mei_release(struct inode *inode, struct file *file)
111 struct mei_cl *cl = file->private_data;
112 struct mei_cl_cb *cb;
113 struct mei_device *dev;
116 if (WARN_ON(!cl || !cl->dev))
121 mutex_lock(&dev->device_lock);
122 if (cl == &dev->iamthif_cl) {
123 rets = mei_amthif_release(dev, file);
126 if (cl->state == MEI_FILE_CONNECTED) {
127 cl->state = MEI_FILE_DISCONNECTING;
128 cl_dbg(dev, cl, "disconnecting\n");
129 rets = mei_cl_disconnect(cl);
131 mei_cl_flush_queues(cl);
132 cl_dbg(dev, cl, "removing\n");
140 cb = mei_cl_find_read_cb(cl);
141 /* Remove entry from read list */
149 file->private_data = NULL;
155 mutex_unlock(&dev->device_lock);
161 * mei_read - the read function.
163 * @file: pointer to file structure
164 * @ubuf: pointer to user buffer
165 * @length: buffer length
166 * @offset: data offset in buffer
168 * returns >=0 data length on success , <0 on error
170 static ssize_t mei_read(struct file *file, char __user *ubuf,
171 size_t length, loff_t *offset)
173 struct mei_cl *cl = file->private_data;
174 struct mei_cl_cb *cb_pos = NULL;
175 struct mei_cl_cb *cb = NULL;
176 struct mei_device *dev;
181 if (WARN_ON(!cl || !cl->dev))
187 mutex_lock(&dev->device_lock);
188 if (dev->dev_state != MEI_DEV_ENABLED) {
198 if (cl == &dev->iamthif_cl) {
199 rets = mei_amthif_read(dev, file, ubuf, length, offset);
206 if (cb->buf_idx > *offset)
208 /* offset is beyond buf_idx we have no more data return 0 */
209 if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
213 /* Offset needs to be cleaned for contiguous reads*/
214 if (cb->buf_idx == 0 && *offset > 0)
216 } else if (*offset > 0) {
220 err = mei_cl_read_start(cl, length);
221 if (err && err != -EBUSY) {
222 dev_dbg(&dev->pdev->dev,
223 "mei start read failure with status = %d\n", err);
228 if (MEI_READ_COMPLETE != cl->reading_state &&
229 !waitqueue_active(&cl->rx_wait)) {
230 if (file->f_flags & O_NONBLOCK) {
235 mutex_unlock(&dev->device_lock);
237 if (wait_event_interruptible(cl->rx_wait,
238 MEI_READ_COMPLETE == cl->reading_state ||
239 mei_cl_is_transitioning(cl))) {
241 if (signal_pending(current))
246 mutex_lock(&dev->device_lock);
247 if (mei_cl_is_transitioning(cl)) {
259 if (cl->reading_state != MEI_READ_COMPLETE) {
263 /* now copy the data to user space */
265 dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
266 cb->response_buffer.size, cb->buf_idx);
267 if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
272 /* length is being truncated to PAGE_SIZE,
273 * however buf_idx may point beyond that */
274 length = min_t(size_t, length, cb->buf_idx - *offset);
276 if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
277 dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
284 if ((unsigned long)*offset < cb->buf_idx)
288 cb_pos = mei_cl_find_read_cb(cl);
289 /* Remove entry from read list */
291 list_del(&cb_pos->list);
293 cl->reading_state = MEI_IDLE;
296 dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
297 mutex_unlock(&dev->device_lock);
301 * mei_write - the write function.
303 * @file: pointer to file structure
304 * @ubuf: pointer to user buffer
305 * @length: buffer length
306 * @offset: data offset in buffer
308 * returns >=0 data length on success , <0 on error
310 static ssize_t mei_write(struct file *file, const char __user *ubuf,
311 size_t length, loff_t *offset)
313 struct mei_cl *cl = file->private_data;
314 struct mei_cl_cb *write_cb = NULL;
315 struct mei_device *dev;
316 unsigned long timeout = 0;
320 if (WARN_ON(!cl || !cl->dev))
325 mutex_lock(&dev->device_lock);
327 if (dev->dev_state != MEI_DEV_ENABLED) {
332 id = mei_me_cl_by_id(dev, cl->me_client_id);
343 if (length > dev->me_clients[id].props.max_msg_length) {
348 if (cl->state != MEI_FILE_CONNECTED) {
349 dev_err(&dev->pdev->dev, "host client = %d, is not connected to ME client = %d",
350 cl->host_client_id, cl->me_client_id);
354 if (cl == &dev->iamthif_cl) {
355 write_cb = mei_amthif_find_read_list_entry(dev, file);
358 timeout = write_cb->read_time +
359 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
361 if (time_after(jiffies, timeout) ||
362 cl->reading_state == MEI_READ_COMPLETE) {
364 list_del(&write_cb->list);
365 mei_io_cb_free(write_cb);
371 /* free entry used in read */
372 if (cl->reading_state == MEI_READ_COMPLETE) {
374 write_cb = mei_cl_find_read_cb(cl);
376 list_del(&write_cb->list);
377 mei_io_cb_free(write_cb);
379 cl->reading_state = MEI_IDLE;
382 } else if (cl->reading_state == MEI_IDLE)
386 write_cb = mei_io_cb_init(cl, file);
388 dev_err(&dev->pdev->dev, "write cb allocation failed\n");
392 rets = mei_io_cb_alloc_req_buf(write_cb, length);
396 rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
398 dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
403 if (cl == &dev->iamthif_cl) {
404 rets = mei_amthif_write(dev, write_cb);
407 dev_err(&dev->pdev->dev,
408 "amthif write failed with status = %d\n", rets);
411 mutex_unlock(&dev->device_lock);
415 rets = mei_cl_write(cl, write_cb, false);
417 mutex_unlock(&dev->device_lock);
419 mei_io_cb_free(write_cb);
424 * mei_ioctl_connect_client - the connect to fw client IOCTL function
426 * @dev: the device structure
427 * @data: IOCTL connect data, input and output parameters
428 * @file: private data of the file object
430 * Locking: called under "dev->device_lock" lock
432 * returns 0 on success, <0 on failure.
434 static int mei_ioctl_connect_client(struct file *file,
435 struct mei_connect_client_data *data)
437 struct mei_device *dev;
438 struct mei_client *client;
443 cl = file->private_data;
444 if (WARN_ON(!cl || !cl->dev))
449 if (dev->dev_state != MEI_DEV_ENABLED) {
454 if (cl->state != MEI_FILE_INITIALIZING &&
455 cl->state != MEI_FILE_DISCONNECTED) {
460 /* find ME client we're trying to connect to */
461 i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
462 if (i < 0 || dev->me_clients[i].props.fixed_address) {
463 dev_dbg(&dev->pdev->dev, "Cannot connect to FW Client UUID = %pUl\n",
464 &data->in_client_uuid);
469 cl->me_client_id = dev->me_clients[i].client_id;
470 cl->state = MEI_FILE_CONNECTING;
472 dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
474 dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
475 dev->me_clients[i].props.protocol_version);
476 dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
477 dev->me_clients[i].props.max_msg_length);
479 /* if we're connecting to amthif client then we will use the
480 * existing connection
482 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
483 dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
484 if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
492 dev->iamthif_open_count++;
493 file->private_data = &dev->iamthif_cl;
495 client = &data->out_client_properties;
496 client->max_msg_length =
497 dev->me_clients[i].props.max_msg_length;
498 client->protocol_version =
499 dev->me_clients[i].props.protocol_version;
500 rets = dev->iamthif_cl.status;
506 /* prepare the output buffer */
507 client = &data->out_client_properties;
508 client->max_msg_length = dev->me_clients[i].props.max_msg_length;
509 client->protocol_version = dev->me_clients[i].props.protocol_version;
510 dev_dbg(&dev->pdev->dev, "Can connect?\n");
513 rets = mei_cl_connect(cl, file);
521 * mei_ioctl - the IOCTL function
523 * @file: pointer to file structure
524 * @cmd: ioctl command
525 * @data: pointer to mei message structure
527 * returns 0 on success , <0 on error
529 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
531 struct mei_device *dev;
532 struct mei_cl *cl = file->private_data;
533 struct mei_connect_client_data *connect_data = NULL;
536 if (cmd != IOCTL_MEI_CONNECT_CLIENT)
539 if (WARN_ON(!cl || !cl->dev))
544 dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);
546 mutex_lock(&dev->device_lock);
547 if (dev->dev_state != MEI_DEV_ENABLED) {
552 dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
554 connect_data = kzalloc(sizeof(struct mei_connect_client_data),
560 dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
561 if (copy_from_user(connect_data, (char __user *)data,
562 sizeof(struct mei_connect_client_data))) {
563 dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
568 rets = mei_ioctl_connect_client(file, connect_data);
570 /* if all is ok, copying the data back to user. */
574 dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
575 if (copy_to_user((char __user *)data, connect_data,
576 sizeof(struct mei_connect_client_data))) {
577 dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
584 mutex_unlock(&dev->device_lock);
589 * mei_compat_ioctl - the compat IOCTL function
591 * @file: pointer to file structure
592 * @cmd: ioctl command
593 * @data: pointer to mei message structure
595 * returns 0 on success , <0 on error
598 static long mei_compat_ioctl(struct file *file,
599 unsigned int cmd, unsigned long data)
601 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
607 * mei_poll - the poll function
609 * @file: pointer to file structure
610 * @wait: pointer to poll_table structure
614 static unsigned int mei_poll(struct file *file, poll_table *wait)
616 struct mei_cl *cl = file->private_data;
617 struct mei_device *dev;
618 unsigned int mask = 0;
620 if (WARN_ON(!cl || !cl->dev))
625 mutex_lock(&dev->device_lock);
627 if (!mei_cl_is_connected(cl)) {
632 mutex_unlock(&dev->device_lock);
635 if (cl == &dev->iamthif_cl)
636 return mei_amthif_poll(dev, file, wait);
638 poll_wait(file, &cl->tx_wait, wait);
640 mutex_lock(&dev->device_lock);
642 if (!mei_cl_is_connected(cl)) {
647 if (MEI_WRITE_COMPLETE == cl->writing_state)
648 mask |= (POLLIN | POLLRDNORM);
651 mutex_unlock(&dev->device_lock);
656 * file operations structure will be used for mei char device.
658 static const struct file_operations mei_fops = {
659 .owner = THIS_MODULE,
661 .unlocked_ioctl = mei_ioctl,
663 .compat_ioctl = mei_compat_ioctl,
666 .release = mei_release,
675 static struct miscdevice mei_misc_device = {
678 .minor = MISC_DYNAMIC_MINOR,
682 int mei_register(struct mei_device *dev)
685 mei_misc_device.parent = &dev->pdev->dev;
686 ret = misc_register(&mei_misc_device);
690 if (mei_dbgfs_register(dev, mei_misc_device.name))
691 dev_err(&dev->pdev->dev, "cannot register debugfs\n");
695 EXPORT_SYMBOL_GPL(mei_register);
697 void mei_deregister(struct mei_device *dev)
699 mei_dbgfs_deregister(dev);
700 misc_deregister(&mei_misc_device);
701 mei_misc_device.parent = NULL;
703 EXPORT_SYMBOL_GPL(mei_deregister);
705 static int __init mei_init(void)
707 return mei_cl_bus_init();
710 static void __exit mei_exit(void)
715 module_init(mei_init);
716 module_exit(mei_exit);
718 MODULE_AUTHOR("Intel Corporation");
719 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
720 MODULE_LICENSE("GPL v2");