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)) {
295 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
301 rets = copy_from_user(cb->buf.data, ubuf, length);
303 dev_dbg(dev->dev, "failed to copy data from userland\n");
309 rets = mei_cl_write(cl, cb);
311 mutex_unlock(&dev->device_lock);
316 * mei_ioctl_connect_client - the connect to fw client IOCTL function
318 * @file: private data of the file object
319 * @data: IOCTL connect data, input and output parameters
321 * Locking: called under "dev->device_lock" lock
323 * Return: 0 on success, <0 on failure.
325 static int mei_ioctl_connect_client(struct file *file,
326 struct mei_connect_client_data *data)
328 struct mei_device *dev;
329 struct mei_client *client;
330 struct mei_me_client *me_cl;
334 cl = file->private_data;
337 if (dev->dev_state != MEI_DEV_ENABLED)
340 if (cl->state != MEI_FILE_INITIALIZING &&
341 cl->state != MEI_FILE_DISCONNECTED)
344 /* find ME client we're trying to connect to */
345 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
347 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
348 &data->in_client_uuid);
353 if (me_cl->props.fixed_address) {
354 bool forbidden = dev->override_fixed_address ?
355 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
357 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
358 &data->in_client_uuid);
364 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
366 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
367 me_cl->props.protocol_version);
368 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
369 me_cl->props.max_msg_length);
371 /* prepare the output buffer */
372 client = &data->out_client_properties;
373 client->max_msg_length = me_cl->props.max_msg_length;
374 client->protocol_version = me_cl->props.protocol_version;
375 dev_dbg(dev->dev, "Can connect?\n");
377 rets = mei_cl_connect(cl, me_cl, file);
380 mei_me_cl_put(me_cl);
385 * mei_ioctl_client_notify_request -
386 * propagate event notification request to client
388 * @file: pointer to file structure
389 * @request: 0 - disable, 1 - enable
391 * Return: 0 on success , <0 on error
393 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
395 struct mei_cl *cl = file->private_data;
397 if (request != MEI_HBM_NOTIFICATION_START &&
398 request != MEI_HBM_NOTIFICATION_STOP)
401 return mei_cl_notify_request(cl, file, (u8)request);
405 * mei_ioctl_client_notify_get - wait for notification request
407 * @file: pointer to file structure
408 * @notify_get: 0 - disable, 1 - enable
410 * Return: 0 on success , <0 on error
412 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
414 struct mei_cl *cl = file->private_data;
416 bool block = (file->f_flags & O_NONBLOCK) == 0;
419 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
423 *notify_get = notify_ev ? 1 : 0;
428 * mei_ioctl - the IOCTL function
430 * @file: pointer to file structure
431 * @cmd: ioctl command
432 * @data: pointer to mei message structure
434 * Return: 0 on success , <0 on error
436 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
438 struct mei_device *dev;
439 struct mei_cl *cl = file->private_data;
440 struct mei_connect_client_data connect_data;
441 u32 notify_get, notify_req;
445 if (WARN_ON(!cl || !cl->dev))
450 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
452 mutex_lock(&dev->device_lock);
453 if (dev->dev_state != MEI_DEV_ENABLED) {
459 case IOCTL_MEI_CONNECT_CLIENT:
460 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
461 if (copy_from_user(&connect_data, (char __user *)data,
462 sizeof(struct mei_connect_client_data))) {
463 dev_dbg(dev->dev, "failed to copy data from userland\n");
468 rets = mei_ioctl_connect_client(file, &connect_data);
472 /* if all is ok, copying the data back to user. */
473 if (copy_to_user((char __user *)data, &connect_data,
474 sizeof(struct mei_connect_client_data))) {
475 dev_dbg(dev->dev, "failed to copy data to userland\n");
482 case IOCTL_MEI_NOTIFY_SET:
483 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
484 if (copy_from_user(¬ify_req,
485 (char __user *)data, sizeof(notify_req))) {
486 dev_dbg(dev->dev, "failed to copy data from userland\n");
490 rets = mei_ioctl_client_notify_request(file, notify_req);
493 case IOCTL_MEI_NOTIFY_GET:
494 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
495 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
499 dev_dbg(dev->dev, "copy connect data to user\n");
500 if (copy_to_user((char __user *)data,
501 ¬ify_get, sizeof(notify_get))) {
502 dev_dbg(dev->dev, "failed to copy data to userland\n");
510 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
515 mutex_unlock(&dev->device_lock);
520 * mei_compat_ioctl - the compat IOCTL function
522 * @file: pointer to file structure
523 * @cmd: ioctl command
524 * @data: pointer to mei message structure
526 * Return: 0 on success , <0 on error
529 static long mei_compat_ioctl(struct file *file,
530 unsigned int cmd, unsigned long data)
532 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
538 * mei_poll - the poll function
540 * @file: pointer to file structure
541 * @wait: pointer to poll_table structure
545 static unsigned int mei_poll(struct file *file, poll_table *wait)
547 unsigned long req_events = poll_requested_events(wait);
548 struct mei_cl *cl = file->private_data;
549 struct mei_device *dev;
550 unsigned int mask = 0;
553 if (WARN_ON(!cl || !cl->dev))
558 mutex_lock(&dev->device_lock);
560 notify_en = cl->notify_en && (req_events & POLLPRI);
562 if (dev->dev_state != MEI_DEV_ENABLED ||
563 !mei_cl_is_connected(cl)) {
569 poll_wait(file, &cl->ev_wait, wait);
574 if (req_events & (POLLIN | POLLRDNORM)) {
575 poll_wait(file, &cl->rx_wait, wait);
577 if (!list_empty(&cl->rd_completed))
578 mask |= POLLIN | POLLRDNORM;
580 mei_cl_read_start(cl, mei_cl_mtu(cl), file);
584 mutex_unlock(&dev->device_lock);
589 * mei_cl_is_write_queued - check if the client has pending writes.
591 * @cl: writing host client
593 * Return: true if client is writing, false otherwise.
595 static bool mei_cl_is_write_queued(struct mei_cl *cl)
597 struct mei_device *dev = cl->dev;
598 struct mei_cl_cb *cb;
600 list_for_each_entry(cb, &dev->write_list, list)
603 list_for_each_entry(cb, &dev->write_waiting_list, list)
610 * mei_fsync - the fsync handler
612 * @fp: pointer to file structure
617 * Return: 0 on success, -ENODEV if client is not connected
619 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
621 struct mei_cl *cl = fp->private_data;
622 struct mei_device *dev;
625 if (WARN_ON(!cl || !cl->dev))
630 mutex_lock(&dev->device_lock);
632 if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
637 while (mei_cl_is_write_queued(cl)) {
638 mutex_unlock(&dev->device_lock);
639 rets = wait_event_interruptible(cl->tx_wait,
640 cl->writing_state == MEI_WRITE_COMPLETE ||
641 !mei_cl_is_connected(cl));
642 mutex_lock(&dev->device_lock);
644 if (signal_pending(current))
648 if (!mei_cl_is_connected(cl)) {
655 mutex_unlock(&dev->device_lock);
660 * mei_fasync - asynchronous io support
662 * @fd: file descriptor
663 * @file: pointer to file structure
666 * Return: negative on error,
667 * 0 if it did no changes,
668 * and positive a process was added or deleted
670 static int mei_fasync(int fd, struct file *file, int band)
673 struct mei_cl *cl = file->private_data;
675 if (!mei_cl_is_connected(cl))
678 return fasync_helper(fd, file, band, &cl->ev_async);
682 * fw_status_show - mei device fw_status attribute show method
684 * @device: device pointer
685 * @attr: attribute pointer
686 * @buf: char out buffer
688 * Return: number of the bytes printed into buf or error
690 static ssize_t fw_status_show(struct device *device,
691 struct device_attribute *attr, char *buf)
693 struct mei_device *dev = dev_get_drvdata(device);
694 struct mei_fw_status fw_status;
698 mutex_lock(&dev->device_lock);
699 err = mei_fw_status(dev, &fw_status);
700 mutex_unlock(&dev->device_lock);
702 dev_err(device, "read fw_status error = %d\n", err);
706 for (i = 0; i < fw_status.count; i++)
707 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
708 fw_status.status[i]);
711 static DEVICE_ATTR_RO(fw_status);
714 * hbm_ver_show - display HBM protocol version negotiated with FW
716 * @device: device pointer
717 * @attr: attribute pointer
718 * @buf: char out buffer
720 * Return: number of the bytes printed into buf or error
722 static ssize_t hbm_ver_show(struct device *device,
723 struct device_attribute *attr, char *buf)
725 struct mei_device *dev = dev_get_drvdata(device);
726 struct hbm_version ver;
728 mutex_lock(&dev->device_lock);
730 mutex_unlock(&dev->device_lock);
732 return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
734 static DEVICE_ATTR_RO(hbm_ver);
737 * hbm_ver_drv_show - display HBM protocol version advertised by driver
739 * @device: device pointer
740 * @attr: attribute pointer
741 * @buf: char out buffer
743 * Return: number of the bytes printed into buf or error
745 static ssize_t hbm_ver_drv_show(struct device *device,
746 struct device_attribute *attr, char *buf)
748 return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
750 static DEVICE_ATTR_RO(hbm_ver_drv);
752 static struct attribute *mei_attrs[] = {
753 &dev_attr_fw_status.attr,
754 &dev_attr_hbm_ver.attr,
755 &dev_attr_hbm_ver_drv.attr,
758 ATTRIBUTE_GROUPS(mei);
761 * file operations structure will be used for mei char device.
763 static const struct file_operations mei_fops = {
764 .owner = THIS_MODULE,
766 .unlocked_ioctl = mei_ioctl,
768 .compat_ioctl = mei_compat_ioctl,
771 .release = mei_release,
775 .fasync = mei_fasync,
779 static struct class *mei_class;
780 static dev_t mei_devt;
781 #define MEI_MAX_DEVS MINORMASK
782 static DEFINE_MUTEX(mei_minor_lock);
783 static DEFINE_IDR(mei_idr);
786 * mei_minor_get - obtain next free device minor number
788 * @dev: device pointer
790 * Return: allocated minor, or -ENOSPC if no free minor left
792 static int mei_minor_get(struct mei_device *dev)
796 mutex_lock(&mei_minor_lock);
797 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
800 else if (ret == -ENOSPC)
801 dev_err(dev->dev, "too many mei devices\n");
803 mutex_unlock(&mei_minor_lock);
808 * mei_minor_free - mark device minor number as free
810 * @dev: device pointer
812 static void mei_minor_free(struct mei_device *dev)
814 mutex_lock(&mei_minor_lock);
815 idr_remove(&mei_idr, dev->minor);
816 mutex_unlock(&mei_minor_lock);
819 int mei_register(struct mei_device *dev, struct device *parent)
821 struct device *clsdev; /* class device */
824 ret = mei_minor_get(dev);
828 /* Fill in the data structures */
829 devno = MKDEV(MAJOR(mei_devt), dev->minor);
830 cdev_init(&dev->cdev, &mei_fops);
831 dev->cdev.owner = parent->driver->owner;
834 ret = cdev_add(&dev->cdev, devno, 1);
836 dev_err(parent, "unable to add device %d:%d\n",
837 MAJOR(mei_devt), dev->minor);
841 clsdev = device_create_with_groups(mei_class, parent, devno,
843 "mei%d", dev->minor);
845 if (IS_ERR(clsdev)) {
846 dev_err(parent, "unable to create device %d:%d\n",
847 MAJOR(mei_devt), dev->minor);
848 ret = PTR_ERR(clsdev);
852 ret = mei_dbgfs_register(dev, dev_name(clsdev));
854 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
861 device_destroy(mei_class, devno);
863 cdev_del(&dev->cdev);
868 EXPORT_SYMBOL_GPL(mei_register);
870 void mei_deregister(struct mei_device *dev)
874 devno = dev->cdev.dev;
875 cdev_del(&dev->cdev);
877 mei_dbgfs_deregister(dev);
879 device_destroy(mei_class, devno);
883 EXPORT_SYMBOL_GPL(mei_deregister);
885 static int __init mei_init(void)
889 mei_class = class_create(THIS_MODULE, "mei");
890 if (IS_ERR(mei_class)) {
891 pr_err("couldn't create class\n");
892 ret = PTR_ERR(mei_class);
896 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
898 pr_err("unable to allocate char dev region\n");
902 ret = mei_cl_bus_init();
904 pr_err("unable to initialize bus\n");
911 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
913 class_destroy(mei_class);
918 static void __exit mei_exit(void)
920 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
921 class_destroy(mei_class);
925 module_init(mei_init);
926 module_exit(mei_exit);
928 MODULE_AUTHOR("Intel Corporation");
929 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
930 MODULE_LICENSE("GPL v2");