2 * Intel Management Engine Interface (Intel MEI) Linux driver
3 * Copyright (c) 2012-2013, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 #include <linux/module.h>
17 #include <linux/device.h>
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/init.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/mutex.h>
24 #include <linux/interrupt.h>
25 #include <linux/mei_cl_bus.h>
30 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
31 #define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev)
34 * __mei_cl_send - internal client send (write)
37 * @buf: buffer to send
38 * @length: buffer length
39 * @blocking: wait for write completion
41 * Return: written size bytes or < 0 on error
43 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
46 struct mei_device *bus;
47 struct mei_cl_cb *cb = NULL;
50 if (WARN_ON(!cl || !cl->dev))
55 mutex_lock(&bus->device_lock);
56 if (bus->dev_state != MEI_DEV_ENABLED) {
61 if (!mei_cl_is_connected(cl)) {
66 /* Check if we have an ME client device */
67 if (!mei_me_cl_is_active(cl->me_cl)) {
72 if (length > mei_cl_mtu(cl)) {
77 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
83 memcpy(cb->buf.data, buf, length);
85 rets = mei_cl_write(cl, cb, blocking);
88 mutex_unlock(&bus->device_lock);
96 * __mei_cl_recv - internal client receive (read)
99 * @buf: buffer to receive
100 * @length: buffer length
102 * Return: read size in bytes of < 0 on error
104 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
106 struct mei_device *bus;
107 struct mei_cl_cb *cb;
111 if (WARN_ON(!cl || !cl->dev))
116 mutex_lock(&bus->device_lock);
117 if (bus->dev_state != MEI_DEV_ENABLED) {
122 cb = mei_cl_read_cb(cl, NULL);
126 rets = mei_cl_read_start(cl, length, NULL);
127 if (rets && rets != -EBUSY)
130 /* wait on event only if there is no other waiter */
131 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
133 mutex_unlock(&bus->device_lock);
135 if (wait_event_interruptible(cl->rx_wait,
136 (!list_empty(&cl->rd_completed)) ||
137 (!mei_cl_is_connected(cl)))) {
139 if (signal_pending(current))
144 mutex_lock(&bus->device_lock);
146 if (!mei_cl_is_connected(cl)) {
152 cb = mei_cl_read_cb(cl, NULL);
164 r_length = min_t(size_t, length, cb->buf_idx);
165 memcpy(buf, cb->buf.data, r_length);
171 mutex_unlock(&bus->device_lock);
177 * mei_cldev_send - me device send (write)
179 * @cldev: me client device
180 * @buf: buffer to send
181 * @length: buffer length
183 * Return: written size in bytes or < 0 on error
185 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
187 struct mei_cl *cl = cldev->cl;
192 return __mei_cl_send(cl, buf, length, 1);
194 EXPORT_SYMBOL_GPL(mei_cldev_send);
197 * mei_cldev_recv - client receive (read)
199 * @cldev: me client device
200 * @buf: buffer to receive
201 * @length: buffer length
203 * Return: read size in bytes of < 0 on error
205 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
207 struct mei_cl *cl = cldev->cl;
212 return __mei_cl_recv(cl, buf, length);
214 EXPORT_SYMBOL_GPL(mei_cldev_recv);
217 * mei_cl_bus_event_work - dispatch rx event for a bus device
218 * and schedule new work
222 static void mei_cl_bus_event_work(struct work_struct *work)
224 struct mei_cl_device *cldev;
226 cldev = container_of(work, struct mei_cl_device, event_work);
229 cldev->event_cb(cldev, cldev->events, cldev->event_context);
233 /* Prepare for the next read */
234 if (cldev->events_mask & BIT(MEI_CL_EVENT_RX))
235 mei_cl_read_start(cldev->cl, 0, NULL);
239 * mei_cl_bus_notify_event - schedule notify cb on bus client
243 void mei_cl_bus_notify_event(struct mei_cl *cl)
245 struct mei_cl_device *cldev = cl->cldev;
247 if (!cldev || !cldev->event_cb)
250 if (!(cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)))
256 set_bit(MEI_CL_EVENT_NOTIF, &cldev->events);
258 schedule_work(&cldev->event_work);
260 cl->notify_ev = false;
264 * mei_cl_bus_rx_event - schedule rx evenet
268 void mei_cl_bus_rx_event(struct mei_cl *cl)
270 struct mei_cl_device *cldev = cl->cldev;
272 if (!cldev || !cldev->event_cb)
275 if (!(cldev->events_mask & BIT(MEI_CL_EVENT_RX)))
278 set_bit(MEI_CL_EVENT_RX, &cldev->events);
280 schedule_work(&cldev->event_work);
284 * mei_cldev_register_event_cb - register event callback
286 * @cldev: me client devices
287 * @event_cb: callback function
288 * @events_mask: requested events bitmask
289 * @context: driver context data
291 * Return: 0 on success
292 * -EALREADY if an callback is already registered
295 int mei_cldev_register_event_cb(struct mei_cl_device *cldev,
296 unsigned long events_mask,
297 mei_cldev_event_cb_t event_cb, void *context)
305 cldev->events_mask = events_mask;
306 cldev->event_cb = event_cb;
307 cldev->event_context = context;
308 INIT_WORK(&cldev->event_work, mei_cl_bus_event_work);
310 if (cldev->events_mask & BIT(MEI_CL_EVENT_RX)) {
311 ret = mei_cl_read_start(cldev->cl, 0, NULL);
312 if (ret && ret != -EBUSY)
316 if (cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)) {
317 mutex_lock(&cldev->cl->dev->device_lock);
318 ret = mei_cl_notify_request(cldev->cl, NULL, event_cb ? 1 : 0);
319 mutex_unlock(&cldev->cl->dev->device_lock);
326 EXPORT_SYMBOL_GPL(mei_cldev_register_event_cb);
329 * mei_cldev_get_drvdata - driver data getter
331 * @cldev: mei client device
333 * Return: driver private data
335 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
337 return dev_get_drvdata(&cldev->dev);
339 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
342 * mei_cldev_set_drvdata - driver data setter
344 * @cldev: mei client device
345 * @data: data to store
347 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
349 dev_set_drvdata(&cldev->dev, data);
351 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
354 * mei_cldev_uuid - return uuid of the underlying me client
356 * @cldev: mei client device
358 * Return: me client uuid
360 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
362 return mei_me_cl_uuid(cldev->me_cl);
364 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
367 * mei_cldev_ver - return protocol version of the underlying me client
369 * @cldev: mei client device
371 * Return: me client protocol version
373 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
375 return mei_me_cl_ver(cldev->me_cl);
377 EXPORT_SYMBOL_GPL(mei_cldev_ver);
380 * mei_cldev_enabled - check whether the device is enabled
382 * @cldev: mei client device
384 * Return: true if me client is initialized and connected
386 bool mei_cldev_enabled(struct mei_cl_device *cldev)
388 return cldev->cl && mei_cl_is_connected(cldev->cl);
390 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
393 * mei_cldev_enable_device - enable me client device
394 * create connection with me client
396 * @cldev: me client device
398 * Return: 0 on success and < 0 on error
400 int mei_cldev_enable(struct mei_cl_device *cldev)
402 struct mei_device *bus = cldev->bus;
409 mutex_lock(&bus->device_lock);
410 cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
411 mutex_unlock(&bus->device_lock);
414 /* update pointers */
419 mutex_lock(&bus->device_lock);
420 if (mei_cl_is_connected(cl)) {
425 if (!mei_me_cl_is_active(cldev->me_cl)) {
426 dev_err(&cldev->dev, "me client is not active\n");
431 ret = mei_cl_connect(cl, cldev->me_cl, NULL);
433 dev_err(&cldev->dev, "cannot connect\n");
436 mutex_unlock(&bus->device_lock);
440 EXPORT_SYMBOL_GPL(mei_cldev_enable);
443 * mei_cldev_disable - disable me client device
444 * disconnect form the me client
446 * @cldev: me client device
448 * Return: 0 on success and < 0 on error
450 int mei_cldev_disable(struct mei_cl_device *cldev)
452 struct mei_device *bus;
456 if (!cldev || !cldev->cl)
463 cldev->event_cb = NULL;
465 mutex_lock(&bus->device_lock);
467 if (!mei_cl_is_connected(cl)) {
468 dev_err(bus->dev, "Already disconnected");
473 err = mei_cl_disconnect(cl);
475 dev_err(bus->dev, "Could not disconnect from the ME client");
478 /* Flush queues and remove any pending read */
479 mei_cl_flush_queues(cl, NULL);
485 mutex_unlock(&bus->device_lock);
488 EXPORT_SYMBOL_GPL(mei_cldev_disable);
491 * mei_cl_device_find - find matching entry in the driver id table
493 * @cldev: me client device
494 * @cldrv: me client driver
496 * Return: id on success; NULL if no id is matching
499 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
500 struct mei_cl_driver *cldrv)
502 const struct mei_cl_device_id *id;
507 uuid = mei_me_cl_uuid(cldev->me_cl);
508 version = mei_me_cl_ver(cldev->me_cl);
510 id = cldrv->id_table;
511 while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
512 if (!uuid_le_cmp(*uuid, id->uuid)) {
516 if (strncmp(cldev->name, id->name,
520 if (id->version != MEI_CL_VERSION_ANY)
521 if (id->version != version)
534 * mei_cl_device_match - device match function
539 * Return: 1 if matching device was found 0 otherwise
541 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
543 struct mei_cl_device *cldev = to_mei_cl_device(dev);
544 struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
545 const struct mei_cl_device_id *found_id;
550 if (!cldev->do_match)
553 if (!cldrv || !cldrv->id_table)
556 found_id = mei_cl_device_find(cldev, cldrv);
564 * mei_cl_device_probe - bus probe function
568 * Return: 0 on success; < 0 otherwise
570 static int mei_cl_device_probe(struct device *dev)
572 struct mei_cl_device *cldev;
573 struct mei_cl_driver *cldrv;
574 const struct mei_cl_device_id *id;
576 cldev = to_mei_cl_device(dev);
577 cldrv = to_mei_cl_driver(dev->driver);
582 if (!cldrv || !cldrv->probe)
585 id = mei_cl_device_find(cldev, cldrv);
589 __module_get(THIS_MODULE);
591 return cldrv->probe(cldev, id);
595 * mei_cl_device_remove - remove device from the bus
599 * Return: 0 on success; < 0 otherwise
601 static int mei_cl_device_remove(struct device *dev)
603 struct mei_cl_device *cldev = to_mei_cl_device(dev);
604 struct mei_cl_driver *cldrv;
607 if (!cldev || !dev->driver)
610 if (cldev->event_cb) {
611 cldev->event_cb = NULL;
612 cancel_work_sync(&cldev->event_work);
615 cldrv = to_mei_cl_driver(dev->driver);
617 ret = cldrv->remove(cldev);
619 module_put(THIS_MODULE);
625 static ssize_t name_show(struct device *dev, struct device_attribute *a,
628 struct mei_cl_device *cldev = to_mei_cl_device(dev);
631 len = snprintf(buf, PAGE_SIZE, "%s", cldev->name);
633 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
635 static DEVICE_ATTR_RO(name);
637 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
640 struct mei_cl_device *cldev = to_mei_cl_device(dev);
641 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
644 len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
646 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
648 static DEVICE_ATTR_RO(uuid);
650 static ssize_t version_show(struct device *dev, struct device_attribute *a,
653 struct mei_cl_device *cldev = to_mei_cl_device(dev);
654 u8 version = mei_me_cl_ver(cldev->me_cl);
657 len = snprintf(buf, PAGE_SIZE, "%02X", version);
659 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
661 static DEVICE_ATTR_RO(version);
663 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
666 struct mei_cl_device *cldev = to_mei_cl_device(dev);
667 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
670 len = snprintf(buf, PAGE_SIZE, "mei:%s:%pUl:", cldev->name, uuid);
671 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
673 static DEVICE_ATTR_RO(modalias);
675 static struct attribute *mei_cldev_attrs[] = {
678 &dev_attr_version.attr,
679 &dev_attr_modalias.attr,
682 ATTRIBUTE_GROUPS(mei_cldev);
685 * mei_cl_device_uevent - me client bus uevent handler
688 * @env: uevent kobject
690 * Return: 0 on success -ENOMEM on when add_uevent_var fails
692 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
694 struct mei_cl_device *cldev = to_mei_cl_device(dev);
695 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
696 u8 version = mei_me_cl_ver(cldev->me_cl);
698 if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
701 if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
704 if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
707 if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
708 cldev->name, uuid, version))
714 static struct bus_type mei_cl_bus_type = {
716 .dev_groups = mei_cldev_groups,
717 .match = mei_cl_device_match,
718 .probe = mei_cl_device_probe,
719 .remove = mei_cl_device_remove,
720 .uevent = mei_cl_device_uevent,
723 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
726 get_device(bus->dev);
731 static void mei_dev_bus_put(struct mei_device *bus)
734 put_device(bus->dev);
737 static void mei_cl_bus_dev_release(struct device *dev)
739 struct mei_cl_device *cldev = to_mei_cl_device(dev);
744 mei_me_cl_put(cldev->me_cl);
745 mei_dev_bus_put(cldev->bus);
749 static struct device_type mei_cl_device_type = {
750 .release = mei_cl_bus_dev_release,
754 * mei_cl_bus_set_name - set device name for me client device
756 * @cldev: me client device
758 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
760 dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
762 mei_me_cl_uuid(cldev->me_cl),
763 mei_me_cl_ver(cldev->me_cl));
767 * mei_cl_bus_dev_alloc - initialize and allocate mei client device
772 * Return: allocated device structur or NULL on allocation failure
774 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
775 struct mei_me_client *me_cl)
777 struct mei_cl_device *cldev;
779 cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
783 device_initialize(&cldev->dev);
784 cldev->dev.parent = bus->dev;
785 cldev->dev.bus = &mei_cl_bus_type;
786 cldev->dev.type = &mei_cl_device_type;
787 cldev->bus = mei_dev_bus_get(bus);
788 cldev->me_cl = mei_me_cl_get(me_cl);
789 mei_cl_bus_set_name(cldev);
791 INIT_LIST_HEAD(&cldev->bus_list);
797 * mei_cl_dev_setup - setup me client device
798 * run fix up routines and set the device name
801 * @cldev: me client device
803 * Return: true if the device is eligible for enumeration
805 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
806 struct mei_cl_device *cldev)
809 mei_cl_bus_dev_fixup(cldev);
811 /* the device name can change during fix up */
813 mei_cl_bus_set_name(cldev);
815 return cldev->do_match == 1;
819 * mei_cl_bus_dev_add - add me client devices
821 * @cldev: me client device
823 * Return: 0 on success; < 0 on failre
825 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
829 dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
830 mei_me_cl_uuid(cldev->me_cl),
831 mei_me_cl_ver(cldev->me_cl));
832 ret = device_add(&cldev->dev);
840 * mei_cl_bus_dev_stop - stop the driver
842 * @cldev: me client device
844 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
847 device_release_driver(&cldev->dev);
851 * mei_cl_bus_dev_destroy - destroy me client devices object
853 * @cldev: me client device
855 * Locking: called under "dev->cl_bus_lock" lock
857 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
860 WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
862 if (!cldev->is_added)
865 device_del(&cldev->dev);
867 list_del_init(&cldev->bus_list);
870 put_device(&cldev->dev);
874 * mei_cl_bus_remove_device - remove a devices form the bus
876 * @cldev: me client device
878 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
880 mei_cl_bus_dev_stop(cldev);
881 mei_cl_bus_dev_destroy(cldev);
885 * mei_cl_bus_remove_devices - remove all devices form the bus
889 void mei_cl_bus_remove_devices(struct mei_device *bus)
891 struct mei_cl_device *cldev, *next;
893 mutex_lock(&bus->cl_bus_lock);
894 list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
895 mei_cl_bus_remove_device(cldev);
896 mutex_unlock(&bus->cl_bus_lock);
901 * mei_cl_bus_dev_init - allocate and initializes an mei client devices
907 * Locking: called under "dev->cl_bus_lock" lock
909 static void mei_cl_bus_dev_init(struct mei_device *bus,
910 struct mei_me_client *me_cl)
912 struct mei_cl_device *cldev;
914 WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
916 dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
918 if (me_cl->bus_added)
921 cldev = mei_cl_bus_dev_alloc(bus, me_cl);
925 me_cl->bus_added = true;
926 list_add_tail(&cldev->bus_list, &bus->device_list);
931 * mei_cl_bus_rescan - scan me clients list and add create
932 * devices for eligible clients
936 void mei_cl_bus_rescan(struct mei_device *bus)
938 struct mei_cl_device *cldev, *n;
939 struct mei_me_client *me_cl;
941 mutex_lock(&bus->cl_bus_lock);
943 down_read(&bus->me_clients_rwsem);
944 list_for_each_entry(me_cl, &bus->me_clients, list)
945 mei_cl_bus_dev_init(bus, me_cl);
946 up_read(&bus->me_clients_rwsem);
948 list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
950 if (!mei_me_cl_is_active(cldev->me_cl)) {
951 mei_cl_bus_remove_device(cldev);
958 if (mei_cl_bus_dev_setup(bus, cldev))
959 mei_cl_bus_dev_add(cldev);
961 list_del_init(&cldev->bus_list);
962 put_device(&cldev->dev);
965 mutex_unlock(&bus->cl_bus_lock);
967 dev_dbg(bus->dev, "rescan end");
970 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
971 struct module *owner)
975 cldrv->driver.name = cldrv->name;
976 cldrv->driver.owner = owner;
977 cldrv->driver.bus = &mei_cl_bus_type;
979 err = driver_register(&cldrv->driver);
983 pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
987 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
989 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
991 driver_unregister(&cldrv->driver);
993 pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
995 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
998 int __init mei_cl_bus_init(void)
1000 return bus_register(&mei_cl_bus_type);
1003 void __exit mei_cl_bus_exit(void)
1005 bus_unregister(&mei_cl_bus_type);