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);
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);
106 if (cl == &dev->iamthif_cl) {
107 rets = mei_amthif_release(dev, file);
110 rets = mei_cl_disconnect(cl);
112 mei_cl_flush_queues(cl, file);
113 cl_dbg(dev, cl, "removing\n");
117 file->private_data = NULL;
121 mutex_unlock(&dev->device_lock);
127 * mei_read - the read function.
129 * @file: pointer to file structure
130 * @ubuf: pointer to user buffer
131 * @length: buffer length
132 * @offset: data offset in buffer
134 * Return: >=0 data length on success , <0 on error
136 static ssize_t mei_read(struct file *file, char __user *ubuf,
137 size_t length, loff_t *offset)
139 struct mei_cl *cl = file->private_data;
140 struct mei_device *dev;
141 struct mei_cl_cb *cb = NULL;
142 bool nonblock = !!(file->f_flags & O_NONBLOCK);
145 if (WARN_ON(!cl || !cl->dev))
151 mutex_lock(&dev->device_lock);
152 if (dev->dev_state != MEI_DEV_ENABLED) {
167 cb = mei_cl_read_cb(cl, file);
174 rets = mei_cl_read_start(cl, length, file);
175 if (rets && rets != -EBUSY) {
176 cl_dbg(dev, cl, "mei start read failure status = %d\n", rets);
185 if (rets == -EBUSY &&
186 !mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, file)) {
192 mutex_unlock(&dev->device_lock);
194 if (wait_event_interruptible(cl->rx_wait,
195 (!list_empty(&cl->rd_completed)) ||
196 (!mei_cl_is_connected(cl)))) {
198 if (signal_pending(current))
203 mutex_lock(&dev->device_lock);
204 if (!mei_cl_is_connected(cl)) {
209 cb = mei_cl_read_cb(cl, file);
213 /* now copy the data to user space */
216 cl_dbg(dev, cl, "read operation failed %d\n", rets);
220 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
221 cb->buf.size, cb->buf_idx, *offset);
222 if (*offset >= cb->buf_idx) {
227 /* length is being truncated to PAGE_SIZE,
228 * however buf_idx may point beyond that */
229 length = min_t(size_t, length, cb->buf_idx - *offset);
231 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
232 dev_dbg(dev->dev, "failed to copy data to userland\n");
239 /* not all data was read, keep the cb */
240 if (*offset < cb->buf_idx)
248 cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
249 mutex_unlock(&dev->device_lock);
253 * mei_write - the write function.
255 * @file: pointer to file structure
256 * @ubuf: pointer to user buffer
257 * @length: buffer length
258 * @offset: data offset in buffer
260 * Return: >=0 data length on success , <0 on error
262 static ssize_t mei_write(struct file *file, const char __user *ubuf,
263 size_t length, loff_t *offset)
265 struct mei_cl *cl = file->private_data;
266 struct mei_cl_cb *cb;
267 struct mei_device *dev;
270 if (WARN_ON(!cl || !cl->dev))
275 mutex_lock(&dev->device_lock);
277 if (dev->dev_state != MEI_DEV_ENABLED) {
282 if (!mei_cl_is_connected(cl)) {
283 cl_err(dev, cl, "is not connected");
288 if (!mei_me_cl_is_active(cl->me_cl)) {
293 if (length > mei_cl_mtu(cl)) {
304 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
310 rets = copy_from_user(cb->buf.data, ubuf, length);
312 dev_dbg(dev->dev, "failed to copy data from userland\n");
318 if (cl == &dev->iamthif_cl) {
319 rets = mei_amthif_write(cl, cb);
325 rets = mei_cl_write(cl, cb);
327 mutex_unlock(&dev->device_lock);
332 * mei_ioctl_connect_client - the connect to fw client IOCTL function
334 * @file: private data of the file object
335 * @data: IOCTL connect data, input and output parameters
337 * Locking: called under "dev->device_lock" lock
339 * Return: 0 on success, <0 on failure.
341 static int mei_ioctl_connect_client(struct file *file,
342 struct mei_connect_client_data *data)
344 struct mei_device *dev;
345 struct mei_client *client;
346 struct mei_me_client *me_cl;
350 cl = file->private_data;
353 if (dev->dev_state != MEI_DEV_ENABLED)
356 if (cl->state != MEI_FILE_INITIALIZING &&
357 cl->state != MEI_FILE_DISCONNECTED)
360 /* find ME client we're trying to connect to */
361 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
363 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
364 &data->in_client_uuid);
369 if (me_cl->props.fixed_address) {
370 bool forbidden = dev->override_fixed_address ?
371 !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
373 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
374 &data->in_client_uuid);
380 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
382 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
383 me_cl->props.protocol_version);
384 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
385 me_cl->props.max_msg_length);
387 /* if we're connecting to amthif client then we will use the
388 * existing connection
390 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
391 dev_dbg(dev->dev, "FW Client is amthi\n");
392 if (!mei_cl_is_connected(&dev->iamthif_cl)) {
400 dev->iamthif_open_count++;
401 file->private_data = &dev->iamthif_cl;
403 client = &data->out_client_properties;
404 client->max_msg_length = me_cl->props.max_msg_length;
405 client->protocol_version = me_cl->props.protocol_version;
406 rets = dev->iamthif_cl.status;
411 /* prepare the output buffer */
412 client = &data->out_client_properties;
413 client->max_msg_length = me_cl->props.max_msg_length;
414 client->protocol_version = me_cl->props.protocol_version;
415 dev_dbg(dev->dev, "Can connect?\n");
417 rets = mei_cl_connect(cl, me_cl, file);
420 mei_me_cl_put(me_cl);
425 * mei_ioctl_client_notify_request -
426 * propagate event notification request to client
428 * @file: pointer to file structure
429 * @request: 0 - disable, 1 - enable
431 * Return: 0 on success , <0 on error
433 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
435 struct mei_cl *cl = file->private_data;
437 if (request != MEI_HBM_NOTIFICATION_START &&
438 request != MEI_HBM_NOTIFICATION_STOP)
441 return mei_cl_notify_request(cl, file, (u8)request);
445 * mei_ioctl_client_notify_get - wait for notification request
447 * @file: pointer to file structure
448 * @notify_get: 0 - disable, 1 - enable
450 * Return: 0 on success , <0 on error
452 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
454 struct mei_cl *cl = file->private_data;
456 bool block = (file->f_flags & O_NONBLOCK) == 0;
459 rets = mei_cl_notify_get(cl, block, ¬ify_ev);
463 *notify_get = notify_ev ? 1 : 0;
468 * mei_ioctl - the IOCTL function
470 * @file: pointer to file structure
471 * @cmd: ioctl command
472 * @data: pointer to mei message structure
474 * Return: 0 on success , <0 on error
476 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
478 struct mei_device *dev;
479 struct mei_cl *cl = file->private_data;
480 struct mei_connect_client_data connect_data;
481 u32 notify_get, notify_req;
485 if (WARN_ON(!cl || !cl->dev))
490 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
492 mutex_lock(&dev->device_lock);
493 if (dev->dev_state != MEI_DEV_ENABLED) {
499 case IOCTL_MEI_CONNECT_CLIENT:
500 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
501 if (copy_from_user(&connect_data, (char __user *)data,
502 sizeof(struct mei_connect_client_data))) {
503 dev_dbg(dev->dev, "failed to copy data from userland\n");
508 rets = mei_ioctl_connect_client(file, &connect_data);
512 /* if all is ok, copying the data back to user. */
513 if (copy_to_user((char __user *)data, &connect_data,
514 sizeof(struct mei_connect_client_data))) {
515 dev_dbg(dev->dev, "failed to copy data to userland\n");
522 case IOCTL_MEI_NOTIFY_SET:
523 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
524 if (copy_from_user(¬ify_req,
525 (char __user *)data, sizeof(notify_req))) {
526 dev_dbg(dev->dev, "failed to copy data from userland\n");
530 rets = mei_ioctl_client_notify_request(file, notify_req);
533 case IOCTL_MEI_NOTIFY_GET:
534 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
535 rets = mei_ioctl_client_notify_get(file, ¬ify_get);
539 dev_dbg(dev->dev, "copy connect data to user\n");
540 if (copy_to_user((char __user *)data,
541 ¬ify_get, sizeof(notify_get))) {
542 dev_dbg(dev->dev, "failed to copy data to userland\n");
550 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd);
555 mutex_unlock(&dev->device_lock);
560 * mei_compat_ioctl - the compat IOCTL function
562 * @file: pointer to file structure
563 * @cmd: ioctl command
564 * @data: pointer to mei message structure
566 * Return: 0 on success , <0 on error
569 static long mei_compat_ioctl(struct file *file,
570 unsigned int cmd, unsigned long data)
572 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
578 * mei_poll - the poll function
580 * @file: pointer to file structure
581 * @wait: pointer to poll_table structure
585 static unsigned int mei_poll(struct file *file, poll_table *wait)
587 unsigned long req_events = poll_requested_events(wait);
588 struct mei_cl *cl = file->private_data;
589 struct mei_device *dev;
590 unsigned int mask = 0;
593 if (WARN_ON(!cl || !cl->dev))
598 mutex_lock(&dev->device_lock);
600 notify_en = cl->notify_en && (req_events & POLLPRI);
602 if (dev->dev_state != MEI_DEV_ENABLED ||
603 !mei_cl_is_connected(cl)) {
609 poll_wait(file, &cl->ev_wait, wait);
614 if (cl == &dev->iamthif_cl) {
615 mask |= mei_amthif_poll(file, wait);
619 if (req_events & (POLLIN | POLLRDNORM)) {
620 poll_wait(file, &cl->rx_wait, wait);
622 if (!list_empty(&cl->rd_completed))
623 mask |= POLLIN | POLLRDNORM;
625 mei_cl_read_start(cl, mei_cl_mtu(cl), file);
629 mutex_unlock(&dev->device_lock);
634 * mei_fasync - asynchronous io support
636 * @fd: file descriptor
637 * @file: pointer to file structure
640 * Return: negative on error,
641 * 0 if it did no changes,
642 * and positive a process was added or deleted
644 static int mei_fasync(int fd, struct file *file, int band)
647 struct mei_cl *cl = file->private_data;
649 if (!mei_cl_is_connected(cl))
652 return fasync_helper(fd, file, band, &cl->ev_async);
656 * fw_status_show - mei device fw_status attribute show method
658 * @device: device pointer
659 * @attr: attribute pointer
660 * @buf: char out buffer
662 * Return: number of the bytes printed into buf or error
664 static ssize_t fw_status_show(struct device *device,
665 struct device_attribute *attr, char *buf)
667 struct mei_device *dev = dev_get_drvdata(device);
668 struct mei_fw_status fw_status;
672 mutex_lock(&dev->device_lock);
673 err = mei_fw_status(dev, &fw_status);
674 mutex_unlock(&dev->device_lock);
676 dev_err(device, "read fw_status error = %d\n", err);
680 for (i = 0; i < fw_status.count; i++)
681 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
682 fw_status.status[i]);
685 static DEVICE_ATTR_RO(fw_status);
688 * hbm_ver_show - display HBM protocol version negotiated with FW
690 * @device: device pointer
691 * @attr: attribute pointer
692 * @buf: char out buffer
694 * Return: number of the bytes printed into buf or error
696 static ssize_t hbm_ver_show(struct device *device,
697 struct device_attribute *attr, char *buf)
699 struct mei_device *dev = dev_get_drvdata(device);
700 struct hbm_version ver;
702 mutex_lock(&dev->device_lock);
704 mutex_unlock(&dev->device_lock);
706 return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
708 static DEVICE_ATTR_RO(hbm_ver);
711 * hbm_ver_drv_show - display HBM protocol version advertised by driver
713 * @device: device pointer
714 * @attr: attribute pointer
715 * @buf: char out buffer
717 * Return: number of the bytes printed into buf or error
719 static ssize_t hbm_ver_drv_show(struct device *device,
720 struct device_attribute *attr, char *buf)
722 return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
724 static DEVICE_ATTR_RO(hbm_ver_drv);
726 static struct attribute *mei_attrs[] = {
727 &dev_attr_fw_status.attr,
728 &dev_attr_hbm_ver.attr,
729 &dev_attr_hbm_ver_drv.attr,
732 ATTRIBUTE_GROUPS(mei);
735 * file operations structure will be used for mei char device.
737 static const struct file_operations mei_fops = {
738 .owner = THIS_MODULE,
740 .unlocked_ioctl = mei_ioctl,
742 .compat_ioctl = mei_compat_ioctl,
745 .release = mei_release,
748 .fasync = mei_fasync,
752 static struct class *mei_class;
753 static dev_t mei_devt;
754 #define MEI_MAX_DEVS MINORMASK
755 static DEFINE_MUTEX(mei_minor_lock);
756 static DEFINE_IDR(mei_idr);
759 * mei_minor_get - obtain next free device minor number
761 * @dev: device pointer
763 * Return: allocated minor, or -ENOSPC if no free minor left
765 static int mei_minor_get(struct mei_device *dev)
769 mutex_lock(&mei_minor_lock);
770 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
773 else if (ret == -ENOSPC)
774 dev_err(dev->dev, "too many mei devices\n");
776 mutex_unlock(&mei_minor_lock);
781 * mei_minor_free - mark device minor number as free
783 * @dev: device pointer
785 static void mei_minor_free(struct mei_device *dev)
787 mutex_lock(&mei_minor_lock);
788 idr_remove(&mei_idr, dev->minor);
789 mutex_unlock(&mei_minor_lock);
792 int mei_register(struct mei_device *dev, struct device *parent)
794 struct device *clsdev; /* class device */
797 ret = mei_minor_get(dev);
801 /* Fill in the data structures */
802 devno = MKDEV(MAJOR(mei_devt), dev->minor);
803 cdev_init(&dev->cdev, &mei_fops);
804 dev->cdev.owner = parent->driver->owner;
807 ret = cdev_add(&dev->cdev, devno, 1);
809 dev_err(parent, "unable to add device %d:%d\n",
810 MAJOR(mei_devt), dev->minor);
814 clsdev = device_create_with_groups(mei_class, parent, devno,
816 "mei%d", dev->minor);
818 if (IS_ERR(clsdev)) {
819 dev_err(parent, "unable to create device %d:%d\n",
820 MAJOR(mei_devt), dev->minor);
821 ret = PTR_ERR(clsdev);
825 ret = mei_dbgfs_register(dev, dev_name(clsdev));
827 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret);
834 device_destroy(mei_class, devno);
836 cdev_del(&dev->cdev);
841 EXPORT_SYMBOL_GPL(mei_register);
843 void mei_deregister(struct mei_device *dev)
847 devno = dev->cdev.dev;
848 cdev_del(&dev->cdev);
850 mei_dbgfs_deregister(dev);
852 device_destroy(mei_class, devno);
856 EXPORT_SYMBOL_GPL(mei_deregister);
858 static int __init mei_init(void)
862 mei_class = class_create(THIS_MODULE, "mei");
863 if (IS_ERR(mei_class)) {
864 pr_err("couldn't create class\n");
865 ret = PTR_ERR(mei_class);
869 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
871 pr_err("unable to allocate char dev region\n");
875 ret = mei_cl_bus_init();
877 pr_err("unable to initialize bus\n");
884 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
886 class_destroy(mei_class);
891 static void __exit mei_exit(void)
893 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
894 class_destroy(mei_class);
898 module_init(mei_init);
899 module_exit(mei_exit);
901 MODULE_AUTHOR("Intel Corporation");
902 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
903 MODULE_LICENSE("GPL v2");