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 (!mei_cl_is_connected(cl)) {
61 /* Check if we have an ME client device */
62 if (!mei_me_cl_is_active(cl->me_cl)) {
67 if (length > mei_cl_mtu(cl)) {
72 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
78 memcpy(cb->buf.data, buf, length);
80 rets = mei_cl_write(cl, cb, blocking);
83 mutex_unlock(&bus->device_lock);
91 * __mei_cl_recv - internal client receive (read)
94 * @buf: buffer to receive
95 * @length: buffer length
97 * Return: read size in bytes of < 0 on error
99 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
101 struct mei_device *bus;
102 struct mei_cl_cb *cb;
106 if (WARN_ON(!cl || !cl->dev))
111 mutex_lock(&bus->device_lock);
113 cb = mei_cl_read_cb(cl, NULL);
117 rets = mei_cl_read_start(cl, length, NULL);
118 if (rets && rets != -EBUSY)
121 /* wait on event only if there is no other waiter */
122 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) {
124 mutex_unlock(&bus->device_lock);
126 if (wait_event_interruptible(cl->rx_wait,
127 (!list_empty(&cl->rd_completed)) ||
128 (!mei_cl_is_connected(cl)))) {
130 if (signal_pending(current))
135 mutex_lock(&bus->device_lock);
137 if (!mei_cl_is_connected(cl)) {
143 cb = mei_cl_read_cb(cl, NULL);
155 r_length = min_t(size_t, length, cb->buf_idx);
156 memcpy(buf, cb->buf.data, r_length);
162 mutex_unlock(&bus->device_lock);
168 * mei_cldev_send - me device send (write)
170 * @cldev: me client device
171 * @buf: buffer to send
172 * @length: buffer length
174 * Return: written size in bytes or < 0 on error
176 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
178 struct mei_cl *cl = cldev->cl;
183 return __mei_cl_send(cl, buf, length, 1);
185 EXPORT_SYMBOL_GPL(mei_cldev_send);
188 * mei_cldev_recv - client receive (read)
190 * @cldev: me client device
191 * @buf: buffer to receive
192 * @length: buffer length
194 * Return: read size in bytes of < 0 on error
196 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
198 struct mei_cl *cl = cldev->cl;
203 return __mei_cl_recv(cl, buf, length);
205 EXPORT_SYMBOL_GPL(mei_cldev_recv);
208 * mei_cl_bus_event_work - dispatch rx event for a bus device
209 * and schedule new work
213 static void mei_cl_bus_event_work(struct work_struct *work)
215 struct mei_cl_device *cldev;
217 cldev = container_of(work, struct mei_cl_device, event_work);
220 cldev->event_cb(cldev, cldev->events, cldev->event_context);
224 /* Prepare for the next read */
225 if (cldev->events_mask & BIT(MEI_CL_EVENT_RX))
226 mei_cl_read_start(cldev->cl, 0, NULL);
230 * mei_cl_bus_notify_event - schedule notify cb on bus client
234 void mei_cl_bus_notify_event(struct mei_cl *cl)
236 struct mei_cl_device *cldev = cl->cldev;
238 if (!cldev || !cldev->event_cb)
241 if (!(cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)))
247 set_bit(MEI_CL_EVENT_NOTIF, &cldev->events);
249 schedule_work(&cldev->event_work);
251 cl->notify_ev = false;
255 * mei_cl_bus_rx_event - schedule rx evenet
259 void mei_cl_bus_rx_event(struct mei_cl *cl)
261 struct mei_cl_device *cldev = cl->cldev;
263 if (!cldev || !cldev->event_cb)
266 if (!(cldev->events_mask & BIT(MEI_CL_EVENT_RX)))
269 set_bit(MEI_CL_EVENT_RX, &cldev->events);
271 schedule_work(&cldev->event_work);
275 * mei_cldev_register_event_cb - register event callback
277 * @cldev: me client devices
278 * @event_cb: callback function
279 * @events_mask: requested events bitmask
280 * @context: driver context data
282 * Return: 0 on success
283 * -EALREADY if an callback is already registered
286 int mei_cldev_register_event_cb(struct mei_cl_device *cldev,
287 unsigned long events_mask,
288 mei_cldev_event_cb_t event_cb, void *context)
296 cldev->events_mask = events_mask;
297 cldev->event_cb = event_cb;
298 cldev->event_context = context;
299 INIT_WORK(&cldev->event_work, mei_cl_bus_event_work);
301 if (cldev->events_mask & BIT(MEI_CL_EVENT_RX)) {
302 ret = mei_cl_read_start(cldev->cl, 0, NULL);
303 if (ret && ret != -EBUSY)
307 if (cldev->events_mask & BIT(MEI_CL_EVENT_NOTIF)) {
308 mutex_lock(&cldev->cl->dev->device_lock);
309 ret = mei_cl_notify_request(cldev->cl, NULL, event_cb ? 1 : 0);
310 mutex_unlock(&cldev->cl->dev->device_lock);
317 EXPORT_SYMBOL_GPL(mei_cldev_register_event_cb);
320 * mei_cldev_get_drvdata - driver data getter
322 * @cldev: mei client device
324 * Return: driver private data
326 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
328 return dev_get_drvdata(&cldev->dev);
330 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
333 * mei_cldev_set_drvdata - driver data setter
335 * @cldev: mei client device
336 * @data: data to store
338 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
340 dev_set_drvdata(&cldev->dev, data);
342 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
345 * mei_cldev_uuid - return uuid of the underlying me client
347 * @cldev: mei client device
349 * Return: me client uuid
351 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
353 return mei_me_cl_uuid(cldev->me_cl);
355 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
358 * mei_cldev_ver - return protocol version of the underlying me client
360 * @cldev: mei client device
362 * Return: me client protocol version
364 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
366 return mei_me_cl_ver(cldev->me_cl);
368 EXPORT_SYMBOL_GPL(mei_cldev_ver);
371 * mei_cldev_enabled - check whether the device is enabled
373 * @cldev: mei client device
375 * Return: true if me client is initialized and connected
377 bool mei_cldev_enabled(struct mei_cl_device *cldev)
379 return cldev->cl && mei_cl_is_connected(cldev->cl);
381 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
384 * mei_cldev_enable_device - enable me client device
385 * create connection with me client
387 * @cldev: me client device
389 * Return: 0 on success and < 0 on error
391 int mei_cldev_enable(struct mei_cl_device *cldev)
393 struct mei_device *bus = cldev->bus;
400 mutex_lock(&bus->device_lock);
401 cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
402 mutex_unlock(&bus->device_lock);
405 /* update pointers */
410 mutex_lock(&bus->device_lock);
411 if (mei_cl_is_connected(cl)) {
416 if (!mei_me_cl_is_active(cldev->me_cl)) {
417 dev_err(&cldev->dev, "me client is not active\n");
422 ret = mei_cl_connect(cl, cldev->me_cl, NULL);
424 dev_err(&cldev->dev, "cannot connect\n");
427 mutex_unlock(&bus->device_lock);
431 EXPORT_SYMBOL_GPL(mei_cldev_enable);
434 * mei_cldev_disable - disable me client device
435 * disconnect form the me client
437 * @cldev: me client device
439 * Return: 0 on success and < 0 on error
441 int mei_cldev_disable(struct mei_cl_device *cldev)
443 struct mei_device *bus;
447 if (!cldev || !cldev->cl)
454 cldev->event_cb = NULL;
456 mutex_lock(&bus->device_lock);
458 if (!mei_cl_is_connected(cl)) {
459 dev_err(bus->dev, "Already disconnected");
464 err = mei_cl_disconnect(cl);
466 dev_err(bus->dev, "Could not disconnect from the ME client");
469 /* Flush queues and remove any pending read */
470 mei_cl_flush_queues(cl, NULL);
476 mutex_unlock(&bus->device_lock);
479 EXPORT_SYMBOL_GPL(mei_cldev_disable);
482 * mei_cl_device_find - find matching entry in the driver id table
484 * @cldev: me client device
485 * @cldrv: me client driver
487 * Return: id on success; NULL if no id is matching
490 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
491 struct mei_cl_driver *cldrv)
493 const struct mei_cl_device_id *id;
498 uuid = mei_me_cl_uuid(cldev->me_cl);
499 version = mei_me_cl_ver(cldev->me_cl);
501 id = cldrv->id_table;
502 while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
503 if (!uuid_le_cmp(*uuid, id->uuid)) {
507 if (strncmp(cldev->name, id->name,
511 if (id->version != MEI_CL_VERSION_ANY)
512 if (id->version != version)
525 * mei_cl_device_match - device match function
530 * Return: 1 if matching device was found 0 otherwise
532 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
534 struct mei_cl_device *cldev = to_mei_cl_device(dev);
535 struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
536 const struct mei_cl_device_id *found_id;
541 if (!cldev->do_match)
544 if (!cldrv || !cldrv->id_table)
547 found_id = mei_cl_device_find(cldev, cldrv);
555 * mei_cl_device_probe - bus probe function
559 * Return: 0 on success; < 0 otherwise
561 static int mei_cl_device_probe(struct device *dev)
563 struct mei_cl_device *cldev;
564 struct mei_cl_driver *cldrv;
565 const struct mei_cl_device_id *id;
567 cldev = to_mei_cl_device(dev);
568 cldrv = to_mei_cl_driver(dev->driver);
573 if (!cldrv || !cldrv->probe)
576 id = mei_cl_device_find(cldev, cldrv);
580 __module_get(THIS_MODULE);
582 return cldrv->probe(cldev, id);
586 * mei_cl_device_remove - remove device from the bus
590 * Return: 0 on success; < 0 otherwise
592 static int mei_cl_device_remove(struct device *dev)
594 struct mei_cl_device *cldev = to_mei_cl_device(dev);
595 struct mei_cl_driver *cldrv;
598 if (!cldev || !dev->driver)
601 if (cldev->event_cb) {
602 cldev->event_cb = NULL;
603 cancel_work_sync(&cldev->event_work);
606 cldrv = to_mei_cl_driver(dev->driver);
608 ret = cldrv->remove(cldev);
610 module_put(THIS_MODULE);
616 static ssize_t name_show(struct device *dev, struct device_attribute *a,
619 struct mei_cl_device *cldev = to_mei_cl_device(dev);
622 len = snprintf(buf, PAGE_SIZE, "%s", cldev->name);
624 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
626 static DEVICE_ATTR_RO(name);
628 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
631 struct mei_cl_device *cldev = to_mei_cl_device(dev);
632 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
635 len = snprintf(buf, PAGE_SIZE, "%pUl", uuid);
637 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
639 static DEVICE_ATTR_RO(uuid);
641 static ssize_t version_show(struct device *dev, struct device_attribute *a,
644 struct mei_cl_device *cldev = to_mei_cl_device(dev);
645 u8 version = mei_me_cl_ver(cldev->me_cl);
648 len = snprintf(buf, PAGE_SIZE, "%02X", version);
650 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
652 static DEVICE_ATTR_RO(version);
654 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
657 struct mei_cl_device *cldev = to_mei_cl_device(dev);
658 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
661 len = snprintf(buf, PAGE_SIZE, "mei:%s:%pUl:", cldev->name, uuid);
662 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
664 static DEVICE_ATTR_RO(modalias);
666 static struct attribute *mei_cldev_attrs[] = {
669 &dev_attr_version.attr,
670 &dev_attr_modalias.attr,
673 ATTRIBUTE_GROUPS(mei_cldev);
676 * mei_cl_device_uevent - me client bus uevent handler
679 * @env: uevent kobject
681 * Return: 0 on success -ENOMEM on when add_uevent_var fails
683 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
685 struct mei_cl_device *cldev = to_mei_cl_device(dev);
686 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
687 u8 version = mei_me_cl_ver(cldev->me_cl);
689 if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
692 if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
695 if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
698 if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
699 cldev->name, uuid, version))
705 static struct bus_type mei_cl_bus_type = {
707 .dev_groups = mei_cldev_groups,
708 .match = mei_cl_device_match,
709 .probe = mei_cl_device_probe,
710 .remove = mei_cl_device_remove,
711 .uevent = mei_cl_device_uevent,
714 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
717 get_device(bus->dev);
722 static void mei_dev_bus_put(struct mei_device *bus)
725 put_device(bus->dev);
728 static void mei_cl_bus_dev_release(struct device *dev)
730 struct mei_cl_device *cldev = to_mei_cl_device(dev);
735 mei_me_cl_put(cldev->me_cl);
736 mei_dev_bus_put(cldev->bus);
740 static struct device_type mei_cl_device_type = {
741 .release = mei_cl_bus_dev_release,
745 * mei_cl_bus_set_name - set device name for me client device
747 * @cldev: me client device
749 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
751 dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
753 mei_me_cl_uuid(cldev->me_cl),
754 mei_me_cl_ver(cldev->me_cl));
758 * mei_cl_bus_dev_alloc - initialize and allocate mei client device
763 * Return: allocated device structur or NULL on allocation failure
765 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
766 struct mei_me_client *me_cl)
768 struct mei_cl_device *cldev;
770 cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
774 device_initialize(&cldev->dev);
775 cldev->dev.parent = bus->dev;
776 cldev->dev.bus = &mei_cl_bus_type;
777 cldev->dev.type = &mei_cl_device_type;
778 cldev->bus = mei_dev_bus_get(bus);
779 cldev->me_cl = mei_me_cl_get(me_cl);
780 mei_cl_bus_set_name(cldev);
782 INIT_LIST_HEAD(&cldev->bus_list);
788 * mei_cl_dev_setup - setup me client device
789 * run fix up routines and set the device name
792 * @cldev: me client device
794 * Return: true if the device is eligible for enumeration
796 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
797 struct mei_cl_device *cldev)
800 mei_cl_bus_dev_fixup(cldev);
802 /* the device name can change during fix up */
804 mei_cl_bus_set_name(cldev);
806 return cldev->do_match == 1;
810 * mei_cl_bus_dev_add - add me client devices
812 * @cldev: me client device
814 * Return: 0 on success; < 0 on failre
816 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
820 dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
821 mei_me_cl_uuid(cldev->me_cl),
822 mei_me_cl_ver(cldev->me_cl));
823 ret = device_add(&cldev->dev);
831 * mei_cl_bus_dev_stop - stop the driver
833 * @cldev: me client device
835 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
838 device_release_driver(&cldev->dev);
842 * mei_cl_bus_dev_destroy - destroy me client devices object
844 * @cldev: me client device
846 * Locking: called under "dev->cl_bus_lock" lock
848 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
851 WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
853 if (!cldev->is_added)
856 device_del(&cldev->dev);
858 list_del_init(&cldev->bus_list);
861 put_device(&cldev->dev);
865 * mei_cl_bus_remove_device - remove a devices form the bus
867 * @cldev: me client device
869 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
871 mei_cl_bus_dev_stop(cldev);
872 mei_cl_bus_dev_destroy(cldev);
876 * mei_cl_bus_remove_devices - remove all devices form the bus
880 void mei_cl_bus_remove_devices(struct mei_device *bus)
882 struct mei_cl_device *cldev, *next;
884 mutex_lock(&bus->cl_bus_lock);
885 list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
886 mei_cl_bus_remove_device(cldev);
887 mutex_unlock(&bus->cl_bus_lock);
892 * mei_cl_bus_dev_init - allocate and initializes an mei client devices
898 * Locking: called under "dev->cl_bus_lock" lock
900 static void mei_cl_bus_dev_init(struct mei_device *bus,
901 struct mei_me_client *me_cl)
903 struct mei_cl_device *cldev;
905 WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
907 dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
909 if (me_cl->bus_added)
912 cldev = mei_cl_bus_dev_alloc(bus, me_cl);
916 me_cl->bus_added = true;
917 list_add_tail(&cldev->bus_list, &bus->device_list);
922 * mei_cl_bus_rescan - scan me clients list and add create
923 * devices for eligible clients
927 void mei_cl_bus_rescan(struct mei_device *bus)
929 struct mei_cl_device *cldev, *n;
930 struct mei_me_client *me_cl;
932 mutex_lock(&bus->cl_bus_lock);
934 down_read(&bus->me_clients_rwsem);
935 list_for_each_entry(me_cl, &bus->me_clients, list)
936 mei_cl_bus_dev_init(bus, me_cl);
937 up_read(&bus->me_clients_rwsem);
939 list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
941 if (!mei_me_cl_is_active(cldev->me_cl)) {
942 mei_cl_bus_remove_device(cldev);
949 if (mei_cl_bus_dev_setup(bus, cldev))
950 mei_cl_bus_dev_add(cldev);
952 list_del_init(&cldev->bus_list);
953 put_device(&cldev->dev);
956 mutex_unlock(&bus->cl_bus_lock);
958 dev_dbg(bus->dev, "rescan end");
961 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
962 struct module *owner)
966 cldrv->driver.name = cldrv->name;
967 cldrv->driver.owner = owner;
968 cldrv->driver.bus = &mei_cl_bus_type;
970 err = driver_register(&cldrv->driver);
974 pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
978 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
980 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
982 driver_unregister(&cldrv->driver);
984 pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
986 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
989 int __init mei_cl_bus_init(void)
991 return bus_register(&mei_cl_bus_type);
994 void __exit mei_cl_bus_exit(void)
996 bus_unregister(&mei_cl_bus_type);