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/signal.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);
107 rets = mei_cl_disconnect(cl);
109 mei_cl_flush_queues(cl, file);
110 cl_dbg(dev, cl, "removing\n");
114 file->private_data = NULL;
118 mutex_unlock(&dev->device_lock);
124 * mei_read - the read function.
126 * @file: pointer to file structure
127 * @ubuf: pointer to user buffer
128 * @length: buffer length
129 * @offset: data offset in buffer
131 * Return: >=0 data length on success , <0 on error
133 static ssize_t mei_read(struct file *file, char __user *ubuf,
134 size_t length, loff_t *offset)
136 struct mei_cl *cl = file->private_data;
137 struct mei_device *dev;
138 struct mei_cl_cb *cb = NULL;
139 bool nonblock = !!(file->f_flags & O_NONBLOCK);
142 if (WARN_ON(!cl || !cl->dev))
148 mutex_lock(&dev->device_lock);
149 if (dev->dev_state != MEI_DEV_ENABLED) {
164 cb = mei_cl_read_cb(cl, file);
171 rets = mei_cl_read_start(cl, length, file);
172 if (rets && rets != -EBUSY) {
173 cl_dbg(dev, cl, "mei start read failure status = %d\n", rets);
182 mutex_unlock(&dev->device_lock);
183 if (wait_event_interruptible(cl->rx_wait,
184 !list_empty(&cl->rd_completed) ||
185 !mei_cl_is_connected(cl))) {
186 if (signal_pending(current))
190 mutex_lock(&dev->device_lock);
192 if (!mei_cl_is_connected(cl)) {
197 cb = mei_cl_read_cb(cl, file);
204 /* now copy the data to user space */
207 cl_dbg(dev, cl, "read operation failed %d\n", rets);
211 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
212 cb->buf.size, cb->buf_idx, *offset);
213 if (*offset >= cb->buf_idx) {
218 /* length is being truncated to PAGE_SIZE,
219 * however buf_idx may point beyond that */
220 length = min_t(size_t, length, cb->buf_idx - *offset);
222 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
223 dev_dbg(dev->dev, "failed to copy data to userland\n");
230 /* not all data was read, keep the cb */
231 if (*offset < cb->buf_idx)
239 cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
240 mutex_unlock(&dev->device_lock);
244 * mei_write - the write function.
246 * @file: pointer to file structure
247 * @ubuf: pointer to user buffer
248 * @length: buffer length
249 * @offset: data offset in buffer
251 * Return: >=0 data length on success , <0 on error
253 static ssize_t mei_write(struct file *file, const char __user *ubuf,
254 size_t length, loff_t *offset)
256 struct mei_cl *cl = file->private_data;
257 struct mei_cl_cb *cb;
258 struct mei_device *dev;
261 if (WARN_ON(!cl || !cl->dev))
266 mutex_lock(&dev->device_lock);
268 if (dev->dev_state != MEI_DEV_ENABLED) {
273 if (!mei_cl_is_connected(cl)) {
274 cl_err(dev, cl, "is not connected");
279 if (!mei_me_cl_is_active(cl->me_cl)) {
284 if (length > mei_cl_mtu(cl)) {
294 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
300 rets = copy_from_user(cb->buf.data, ubuf, length);
302 dev_dbg(dev->dev, "failed to copy data from userland\n");
308 rets = mei_cl_write(cl, cb);
310 mutex_unlock(&dev->device_lock);
315 * mei_ioctl_connect_client - the connect to fw client IOCTL function
317 * @file: private data of the file object
318 * @data: IOCTL connect data, input and output parameters
320 * Locking: called under "dev->device_lock" lock
322 * Return: 0 on success, <0 on failure.
324 static int mei_ioctl_connect_client(struct file *file,
325 struct mei_connect_client_data *data)
327 struct mei_device *dev;
328 struct mei_client *client;
329 struct mei_me_client *me_cl;
333 cl = file->private_data;
336 if (dev->dev_state != MEI_DEV_ENABLED)
339 if (cl->state != MEI_FILE_INITIALIZING &&
340 cl->state != MEI_FILE_DISCONNECTED)
343 /* find ME client we're trying to connect to */
344 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
346 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
347 &data->in_client_uuid);
352 if (me_cl->props.fixed_address) {
353 bool forbidden = dev->override_fixed_address ?
354 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
356 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
357 &data->in_client_uuid);
363 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
365 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
366 me_cl->props.protocol_version);
367 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
368 me_cl->props.max_msg_length);
370 /* prepare the output buffer */
371 client = &data->out_client_properties;
372 client->max_msg_length = me_cl->props.max_msg_length;
373 client->protocol_version = me_cl->props.protocol_version;
374 dev_dbg(dev->dev, "Can connect?\n");
376 rets = mei_cl_connect(cl, me_cl, file);
379 mei_me_cl_put(me_cl);
384 * mei_ioctl_client_notify_request -
385 * propagate event notification request to client
387 * @file: pointer to file structure
388 * @request: 0 - disable, 1 - enable
390 * Return: 0 on success , <0 on error
392 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
394 struct mei_cl *cl = file->private_data;
396 if (request != MEI_HBM_NOTIFICATION_START &&
397 request != MEI_HBM_NOTIFICATION_STOP)
400 return mei_cl_notify_request(cl, file, (u8)request);
404 * mei_ioctl_client_notify_get - wait for notification request
406 * @file: pointer to file structure
407 * @notify_get: 0 - disable, 1 - enable
409 * Return: 0 on success , <0 on error
411 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
413 struct mei_cl *cl = file->private_data;
415 bool block = (file->f_flags & O_NONBLOCK) == 0;
418 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
422 *notify_get = notify_ev ? 1 : 0;
427 * mei_ioctl - the IOCTL function
429 * @file: pointer to file structure
430 * @cmd: ioctl command
431 * @data: pointer to mei message structure
433 * Return: 0 on success , <0 on error
435 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
437 struct mei_device *dev;
438 struct mei_cl *cl = file->private_data;
439 struct mei_connect_client_data connect_data;
440 u32 notify_get, notify_req;
444 if (WARN_ON(!cl || !cl->dev))
449 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
451 mutex_lock(&dev->device_lock);
452 if (dev->dev_state != MEI_DEV_ENABLED) {
458 case IOCTL_MEI_CONNECT_CLIENT:
459 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
460 if (copy_from_user(&connect_data, (char __user *)data,
461 sizeof(struct mei_connect_client_data))) {
462 dev_dbg(dev->dev, "failed to copy data from userland\n");
467 rets = mei_ioctl_connect_client(file, &connect_data);
471 /* if all is ok, copying the data back to user. */
472 if (copy_to_user((char __user *)data, &connect_data,
473 sizeof(struct mei_connect_client_data))) {
474 dev_dbg(dev->dev, "failed to copy data to userland\n");
481 case IOCTL_MEI_NOTIFY_SET:
482 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
483 if (copy_from_user(¬ify_req,
484 (char __user *)data, sizeof(notify_req))) {
485 dev_dbg(dev->dev, "failed to copy data from userland\n");
489 rets = mei_ioctl_client_notify_request(file, notify_req);
492 case IOCTL_MEI_NOTIFY_GET:
493 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
494 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
498 dev_dbg(dev->dev, "copy connect data to user\n");
499 if (copy_to_user((char __user *)data,
500 ¬ify_get, sizeof(notify_get))) {
501 dev_dbg(dev->dev, "failed to copy data to userland\n");
513 mutex_unlock(&dev->device_lock);
518 * mei_compat_ioctl - the compat IOCTL function
520 * @file: pointer to file structure
521 * @cmd: ioctl command
522 * @data: pointer to mei message structure
524 * Return: 0 on success , <0 on error
527 static long mei_compat_ioctl(struct file *file,
528 unsigned int cmd, unsigned long data)
530 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
536 * mei_poll - the poll function
538 * @file: pointer to file structure
539 * @wait: pointer to poll_table structure
543 static unsigned int mei_poll(struct file *file, poll_table *wait)
545 unsigned long req_events = poll_requested_events(wait);
546 struct mei_cl *cl = file->private_data;
547 struct mei_device *dev;
548 unsigned int mask = 0;
551 if (WARN_ON(!cl || !cl->dev))
556 mutex_lock(&dev->device_lock);
558 notify_en = cl->notify_en && (req_events & POLLPRI);
560 if (dev->dev_state != MEI_DEV_ENABLED ||
561 !mei_cl_is_connected(cl)) {
567 poll_wait(file, &cl->ev_wait, wait);
572 if (req_events & (POLLIN | POLLRDNORM)) {
573 poll_wait(file, &cl->rx_wait, wait);
575 if (!list_empty(&cl->rd_completed))
576 mask |= POLLIN | POLLRDNORM;
578 mei_cl_read_start(cl, mei_cl_mtu(cl), file);
582 mutex_unlock(&dev->device_lock);
587 * mei_cl_is_write_queued - check if the client has pending writes.
589 * @cl: writing host client
591 * Return: true if client is writing, false otherwise.
593 static bool mei_cl_is_write_queued(struct mei_cl *cl)
595 struct mei_device *dev = cl->dev;
596 struct mei_cl_cb *cb;
598 list_for_each_entry(cb, &dev->write_list, list)
601 list_for_each_entry(cb, &dev->write_waiting_list, list)
608 * mei_fsync - the fsync handler
610 * @fp: pointer to file structure
615 * Return: 0 on success, -ENODEV if client is not connected
617 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
619 struct mei_cl *cl = fp->private_data;
620 struct mei_device *dev;
623 if (WARN_ON(!cl || !cl->dev))
628 mutex_lock(&dev->device_lock);
630 if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
635 while (mei_cl_is_write_queued(cl)) {
636 mutex_unlock(&dev->device_lock);
637 rets = wait_event_interruptible(cl->tx_wait,
638 cl->writing_state == MEI_WRITE_COMPLETE ||
639 !mei_cl_is_connected(cl));
640 mutex_lock(&dev->device_lock);
642 if (signal_pending(current))
646 if (!mei_cl_is_connected(cl)) {
653 mutex_unlock(&dev->device_lock);
658 * mei_fasync - asynchronous io support
660 * @fd: file descriptor
661 * @file: pointer to file structure
664 * Return: negative on error,
665 * 0 if it did no changes,
666 * and positive a process was added or deleted
668 static int mei_fasync(int fd, struct file *file, int band)
671 struct mei_cl *cl = file->private_data;
673 if (!mei_cl_is_connected(cl))
676 return fasync_helper(fd, file, band, &cl->ev_async);
680 * fw_status_show - mei device fw_status attribute show method
682 * @device: device pointer
683 * @attr: attribute pointer
684 * @buf: char out buffer
686 * Return: number of the bytes printed into buf or error
688 static ssize_t fw_status_show(struct device *device,
689 struct device_attribute *attr, char *buf)
691 struct mei_device *dev = dev_get_drvdata(device);
692 struct mei_fw_status fw_status;
696 mutex_lock(&dev->device_lock);
697 err = mei_fw_status(dev, &fw_status);
698 mutex_unlock(&dev->device_lock);
700 dev_err(device, "read fw_status error = %d\n", err);
704 for (i = 0; i < fw_status.count; i++)
705 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
706 fw_status.status[i]);
709 static DEVICE_ATTR_RO(fw_status);
712 * hbm_ver_show - display HBM protocol version negotiated with FW
714 * @device: device pointer
715 * @attr: attribute pointer
716 * @buf: char out buffer
718 * Return: number of the bytes printed into buf or error
720 static ssize_t hbm_ver_show(struct device *device,
721 struct device_attribute *attr, char *buf)
723 struct mei_device *dev = dev_get_drvdata(device);
724 struct hbm_version ver;
726 mutex_lock(&dev->device_lock);
728 mutex_unlock(&dev->device_lock);
730 return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
732 static DEVICE_ATTR_RO(hbm_ver);
735 * hbm_ver_drv_show - display HBM protocol version advertised by driver
737 * @device: device pointer
738 * @attr: attribute pointer
739 * @buf: char out buffer
741 * Return: number of the bytes printed into buf or error
743 static ssize_t hbm_ver_drv_show(struct device *device,
744 struct device_attribute *attr, char *buf)
746 return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
748 static DEVICE_ATTR_RO(hbm_ver_drv);
750 static struct attribute *mei_attrs[] = {
751 &dev_attr_fw_status.attr,
752 &dev_attr_hbm_ver.attr,
753 &dev_attr_hbm_ver_drv.attr,
756 ATTRIBUTE_GROUPS(mei);
759 * file operations structure will be used for mei char device.
761 static const struct file_operations mei_fops = {
762 .owner = THIS_MODULE,
764 .unlocked_ioctl = mei_ioctl,
766 .compat_ioctl = mei_compat_ioctl,
769 .release = mei_release,
773 .fasync = mei_fasync,
777 static struct class *mei_class;
778 static dev_t mei_devt;
779 #define MEI_MAX_DEVS MINORMASK
780 static DEFINE_MUTEX(mei_minor_lock);
781 static DEFINE_IDR(mei_idr);
784 * mei_minor_get - obtain next free device minor number
786 * @dev: device pointer
788 * Return: allocated minor, or -ENOSPC if no free minor left
790 static int mei_minor_get(struct mei_device *dev)
794 mutex_lock(&mei_minor_lock);
795 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
798 else if (ret == -ENOSPC)
799 dev_err(dev->dev, "too many mei devices\n");
801 mutex_unlock(&mei_minor_lock);
806 * mei_minor_free - mark device minor number as free
808 * @dev: device pointer
810 static void mei_minor_free(struct mei_device *dev)
812 mutex_lock(&mei_minor_lock);
813 idr_remove(&mei_idr, dev->minor);
814 mutex_unlock(&mei_minor_lock);
817 int mei_register(struct mei_device *dev, struct device *parent)
819 struct device *clsdev; /* class device */
822 ret = mei_minor_get(dev);
826 /* Fill in the data structures */
827 devno = MKDEV(MAJOR(mei_devt), dev->minor);
828 cdev_init(&dev->cdev, &mei_fops);
829 dev->cdev.owner = parent->driver->owner;
832 ret = cdev_add(&dev->cdev, devno, 1);
834 dev_err(parent, "unable to add device %d:%d\n",
835 MAJOR(mei_devt), dev->minor);
839 clsdev = device_create_with_groups(mei_class, parent, devno,
841 "mei%d", dev->minor);
843 if (IS_ERR(clsdev)) {
844 dev_err(parent, "unable to create device %d:%d\n",
845 MAJOR(mei_devt), dev->minor);
846 ret = PTR_ERR(clsdev);
850 ret = mei_dbgfs_register(dev, dev_name(clsdev));
852 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
859 device_destroy(mei_class, devno);
861 cdev_del(&dev->cdev);
866 EXPORT_SYMBOL_GPL(mei_register);
868 void mei_deregister(struct mei_device *dev)
872 devno = dev->cdev.dev;
873 cdev_del(&dev->cdev);
875 mei_dbgfs_deregister(dev);
877 device_destroy(mei_class, devno);
881 EXPORT_SYMBOL_GPL(mei_deregister);
883 static int __init mei_init(void)
887 mei_class = class_create(THIS_MODULE, "mei");
888 if (IS_ERR(mei_class)) {
889 pr_err("couldn't create class\n");
890 ret = PTR_ERR(mei_class);
894 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
896 pr_err("unable to allocate char dev region\n");
900 ret = mei_cl_bus_init();
902 pr_err("unable to initialize bus\n");
909 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
911 class_destroy(mei_class);
916 static void __exit mei_exit(void)
918 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
919 class_destroy(mei_class);
923 module_init(mei_init);
924 module_exit(mei_exit);
926 MODULE_AUTHOR("Intel Corporation");
927 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
928 MODULE_LICENSE("GPL v2");