1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
4 * Intel Management Engine Interface (Intel MEI) Linux driver
5 */
6
7 #include <linux/module.h>
8 #include <linux/device.h>
9 #include <linux/kernel.h>
10 #include <linux/sched/signal.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/slab.h>
14 #include <linux/mutex.h>
15 #include <linux/interrupt.h>
16 #include <linux/mei_cl_bus.h>
17
18 #include "mei_dev.h"
19 #include "client.h"
20
21 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver)
22
23 /**
24 * __mei_cl_send - internal client send (write)
25 *
26 * @cl: host client
27 * @buf: buffer to send
28 * @length: buffer length
29 * @mode: sending mode
30 *
31 * Return: written size bytes or < 0 on error
32 */
__mei_cl_send(struct mei_cl * cl,u8 * buf,size_t length,unsigned int mode)33 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
34 unsigned int mode)
35 {
36 struct mei_device *bus;
37 struct mei_cl_cb *cb;
38 ssize_t rets;
39
40 if (WARN_ON(!cl || !cl->dev))
41 return -ENODEV;
42
43 bus = cl->dev;
44
45 mutex_lock(&bus->device_lock);
46 if (bus->dev_state != MEI_DEV_ENABLED) {
47 rets = -ENODEV;
48 goto out;
49 }
50
51 if (!mei_cl_is_connected(cl)) {
52 rets = -ENODEV;
53 goto out;
54 }
55
56 /* Check if we have an ME client device */
57 if (!mei_me_cl_is_active(cl->me_cl)) {
58 rets = -ENOTTY;
59 goto out;
60 }
61
62 if (length > mei_cl_mtu(cl)) {
63 rets = -EFBIG;
64 goto out;
65 }
66
67 while (cl->tx_cb_queued >= bus->tx_queue_limit) {
68 mutex_unlock(&bus->device_lock);
69 rets = wait_event_interruptible(cl->tx_wait,
70 cl->writing_state == MEI_WRITE_COMPLETE ||
71 (!mei_cl_is_connected(cl)));
72 mutex_lock(&bus->device_lock);
73 if (rets) {
74 if (signal_pending(current))
75 rets = -EINTR;
76 goto out;
77 }
78 if (!mei_cl_is_connected(cl)) {
79 rets = -ENODEV;
80 goto out;
81 }
82 }
83
84 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL);
85 if (!cb) {
86 rets = -ENOMEM;
87 goto out;
88 }
89
90 cb->internal = !!(mode & MEI_CL_IO_TX_INTERNAL);
91 cb->blocking = !!(mode & MEI_CL_IO_TX_BLOCKING);
92 memcpy(cb->buf.data, buf, length);
93
94 rets = mei_cl_write(cl, cb);
95
96 out:
97 mutex_unlock(&bus->device_lock);
98
99 return rets;
100 }
101
102 /**
103 * __mei_cl_recv - internal client receive (read)
104 *
105 * @cl: host client
106 * @buf: buffer to receive
107 * @length: buffer length
108 * @mode: io mode
109 * @timeout: recv timeout, 0 for infinite timeout
110 *
111 * Return: read size in bytes of < 0 on error
112 */
__mei_cl_recv(struct mei_cl * cl,u8 * buf,size_t length,unsigned int mode,unsigned long timeout)113 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
114 unsigned int mode, unsigned long timeout)
115 {
116 struct mei_device *bus;
117 struct mei_cl_cb *cb;
118 size_t r_length;
119 ssize_t rets;
120 bool nonblock = !!(mode & MEI_CL_IO_RX_NONBLOCK);
121
122 if (WARN_ON(!cl || !cl->dev))
123 return -ENODEV;
124
125 bus = cl->dev;
126
127 mutex_lock(&bus->device_lock);
128 if (bus->dev_state != MEI_DEV_ENABLED) {
129 rets = -ENODEV;
130 goto out;
131 }
132
133 cb = mei_cl_read_cb(cl, NULL);
134 if (cb)
135 goto copy;
136
137 rets = mei_cl_read_start(cl, length, NULL);
138 if (rets && rets != -EBUSY)
139 goto out;
140
141 if (nonblock) {
142 rets = -EAGAIN;
143 goto out;
144 }
145
146 /* wait on event only if there is no other waiter */
147 /* synchronized under device mutex */
148 if (!waitqueue_active(&cl->rx_wait)) {
149
150 mutex_unlock(&bus->device_lock);
151
152 if (timeout) {
153 rets = wait_event_interruptible_timeout
154 (cl->rx_wait,
155 (!list_empty(&cl->rd_completed)) ||
156 (!mei_cl_is_connected(cl)),
157 msecs_to_jiffies(timeout));
158 if (rets == 0)
159 return -ETIME;
160 if (rets < 0) {
161 if (signal_pending(current))
162 return -EINTR;
163 return -ERESTARTSYS;
164 }
165 } else {
166 if (wait_event_interruptible
167 (cl->rx_wait,
168 (!list_empty(&cl->rd_completed)) ||
169 (!mei_cl_is_connected(cl)))) {
170 if (signal_pending(current))
171 return -EINTR;
172 return -ERESTARTSYS;
173 }
174 }
175
176 mutex_lock(&bus->device_lock);
177
178 if (!mei_cl_is_connected(cl)) {
179 rets = -ENODEV;
180 goto out;
181 }
182 }
183
184 cb = mei_cl_read_cb(cl, NULL);
185 if (!cb) {
186 rets = 0;
187 goto out;
188 }
189
190 copy:
191 if (cb->status) {
192 rets = cb->status;
193 goto free;
194 }
195
196 r_length = min_t(size_t, length, cb->buf_idx);
197 memcpy(buf, cb->buf.data, r_length);
198 rets = r_length;
199
200 free:
201 mei_io_cb_free(cb);
202 out:
203 mutex_unlock(&bus->device_lock);
204
205 return rets;
206 }
207
208 /**
209 * mei_cldev_send - me device send (write)
210 *
211 * @cldev: me client device
212 * @buf: buffer to send
213 * @length: buffer length
214 *
215 * Return: written size in bytes or < 0 on error
216 */
mei_cldev_send(struct mei_cl_device * cldev,u8 * buf,size_t length)217 ssize_t mei_cldev_send(struct mei_cl_device *cldev, u8 *buf, size_t length)
218 {
219 struct mei_cl *cl = cldev->cl;
220
221 return __mei_cl_send(cl, buf, length, MEI_CL_IO_TX_BLOCKING);
222 }
223 EXPORT_SYMBOL_GPL(mei_cldev_send);
224
225 /**
226 * mei_cldev_recv_nonblock - non block client receive (read)
227 *
228 * @cldev: me client device
229 * @buf: buffer to receive
230 * @length: buffer length
231 *
232 * Return: read size in bytes of < 0 on error
233 * -EAGAIN if function will block.
234 */
mei_cldev_recv_nonblock(struct mei_cl_device * cldev,u8 * buf,size_t length)235 ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
236 size_t length)
237 {
238 struct mei_cl *cl = cldev->cl;
239
240 return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
241 }
242 EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
243
244 /**
245 * mei_cldev_recv - client receive (read)
246 *
247 * @cldev: me client device
248 * @buf: buffer to receive
249 * @length: buffer length
250 *
251 * Return: read size in bytes of < 0 on error
252 */
mei_cldev_recv(struct mei_cl_device * cldev,u8 * buf,size_t length)253 ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
254 {
255 struct mei_cl *cl = cldev->cl;
256
257 return __mei_cl_recv(cl, buf, length, 0, 0);
258 }
259 EXPORT_SYMBOL_GPL(mei_cldev_recv);
260
261 /**
262 * mei_cl_bus_rx_work - dispatch rx event for a bus device
263 *
264 * @work: work
265 */
mei_cl_bus_rx_work(struct work_struct * work)266 static void mei_cl_bus_rx_work(struct work_struct *work)
267 {
268 struct mei_cl_device *cldev;
269 struct mei_device *bus;
270
271 cldev = container_of(work, struct mei_cl_device, rx_work);
272
273 bus = cldev->bus;
274
275 if (cldev->rx_cb)
276 cldev->rx_cb(cldev);
277
278 mutex_lock(&bus->device_lock);
279 mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
280 mutex_unlock(&bus->device_lock);
281 }
282
283 /**
284 * mei_cl_bus_notif_work - dispatch FW notif event for a bus device
285 *
286 * @work: work
287 */
mei_cl_bus_notif_work(struct work_struct * work)288 static void mei_cl_bus_notif_work(struct work_struct *work)
289 {
290 struct mei_cl_device *cldev;
291
292 cldev = container_of(work, struct mei_cl_device, notif_work);
293
294 if (cldev->notif_cb)
295 cldev->notif_cb(cldev);
296 }
297
298 /**
299 * mei_cl_bus_notify_event - schedule notify cb on bus client
300 *
301 * @cl: host client
302 *
303 * Return: true if event was scheduled
304 * false if the client is not waiting for event
305 */
mei_cl_bus_notify_event(struct mei_cl * cl)306 bool mei_cl_bus_notify_event(struct mei_cl *cl)
307 {
308 struct mei_cl_device *cldev = cl->cldev;
309
310 if (!cldev || !cldev->notif_cb)
311 return false;
312
313 if (!cl->notify_ev)
314 return false;
315
316 schedule_work(&cldev->notif_work);
317
318 cl->notify_ev = false;
319
320 return true;
321 }
322
323 /**
324 * mei_cl_bus_rx_event - schedule rx event
325 *
326 * @cl: host client
327 *
328 * Return: true if event was scheduled
329 * false if the client is not waiting for event
330 */
mei_cl_bus_rx_event(struct mei_cl * cl)331 bool mei_cl_bus_rx_event(struct mei_cl *cl)
332 {
333 struct mei_cl_device *cldev = cl->cldev;
334
335 if (!cldev || !cldev->rx_cb)
336 return false;
337
338 schedule_work(&cldev->rx_work);
339
340 return true;
341 }
342
343 /**
344 * mei_cldev_register_rx_cb - register Rx event callback
345 *
346 * @cldev: me client devices
347 * @rx_cb: callback function
348 *
349 * Return: 0 on success
350 * -EALREADY if an callback is already registered
351 * <0 on other errors
352 */
mei_cldev_register_rx_cb(struct mei_cl_device * cldev,mei_cldev_cb_t rx_cb)353 int mei_cldev_register_rx_cb(struct mei_cl_device *cldev, mei_cldev_cb_t rx_cb)
354 {
355 struct mei_device *bus = cldev->bus;
356 int ret;
357
358 if (!rx_cb)
359 return -EINVAL;
360 if (cldev->rx_cb)
361 return -EALREADY;
362
363 cldev->rx_cb = rx_cb;
364 INIT_WORK(&cldev->rx_work, mei_cl_bus_rx_work);
365
366 mutex_lock(&bus->device_lock);
367 ret = mei_cl_read_start(cldev->cl, mei_cl_mtu(cldev->cl), NULL);
368 mutex_unlock(&bus->device_lock);
369 if (ret && ret != -EBUSY)
370 return ret;
371
372 return 0;
373 }
374 EXPORT_SYMBOL_GPL(mei_cldev_register_rx_cb);
375
376 /**
377 * mei_cldev_register_notif_cb - register FW notification event callback
378 *
379 * @cldev: me client devices
380 * @notif_cb: callback function
381 *
382 * Return: 0 on success
383 * -EALREADY if an callback is already registered
384 * <0 on other errors
385 */
mei_cldev_register_notif_cb(struct mei_cl_device * cldev,mei_cldev_cb_t notif_cb)386 int mei_cldev_register_notif_cb(struct mei_cl_device *cldev,
387 mei_cldev_cb_t notif_cb)
388 {
389 struct mei_device *bus = cldev->bus;
390 int ret;
391
392 if (!notif_cb)
393 return -EINVAL;
394
395 if (cldev->notif_cb)
396 return -EALREADY;
397
398 cldev->notif_cb = notif_cb;
399 INIT_WORK(&cldev->notif_work, mei_cl_bus_notif_work);
400
401 mutex_lock(&bus->device_lock);
402 ret = mei_cl_notify_request(cldev->cl, NULL, 1);
403 mutex_unlock(&bus->device_lock);
404 if (ret)
405 return ret;
406
407 return 0;
408 }
409 EXPORT_SYMBOL_GPL(mei_cldev_register_notif_cb);
410
411 /**
412 * mei_cldev_get_drvdata - driver data getter
413 *
414 * @cldev: mei client device
415 *
416 * Return: driver private data
417 */
mei_cldev_get_drvdata(const struct mei_cl_device * cldev)418 void *mei_cldev_get_drvdata(const struct mei_cl_device *cldev)
419 {
420 return dev_get_drvdata(&cldev->dev);
421 }
422 EXPORT_SYMBOL_GPL(mei_cldev_get_drvdata);
423
424 /**
425 * mei_cldev_set_drvdata - driver data setter
426 *
427 * @cldev: mei client device
428 * @data: data to store
429 */
mei_cldev_set_drvdata(struct mei_cl_device * cldev,void * data)430 void mei_cldev_set_drvdata(struct mei_cl_device *cldev, void *data)
431 {
432 dev_set_drvdata(&cldev->dev, data);
433 }
434 EXPORT_SYMBOL_GPL(mei_cldev_set_drvdata);
435
436 /**
437 * mei_cldev_uuid - return uuid of the underlying me client
438 *
439 * @cldev: mei client device
440 *
441 * Return: me client uuid
442 */
mei_cldev_uuid(const struct mei_cl_device * cldev)443 const uuid_le *mei_cldev_uuid(const struct mei_cl_device *cldev)
444 {
445 return mei_me_cl_uuid(cldev->me_cl);
446 }
447 EXPORT_SYMBOL_GPL(mei_cldev_uuid);
448
449 /**
450 * mei_cldev_ver - return protocol version of the underlying me client
451 *
452 * @cldev: mei client device
453 *
454 * Return: me client protocol version
455 */
mei_cldev_ver(const struct mei_cl_device * cldev)456 u8 mei_cldev_ver(const struct mei_cl_device *cldev)
457 {
458 return mei_me_cl_ver(cldev->me_cl);
459 }
460 EXPORT_SYMBOL_GPL(mei_cldev_ver);
461
462 /**
463 * mei_cldev_enabled - check whether the device is enabled
464 *
465 * @cldev: mei client device
466 *
467 * Return: true if me client is initialized and connected
468 */
mei_cldev_enabled(struct mei_cl_device * cldev)469 bool mei_cldev_enabled(struct mei_cl_device *cldev)
470 {
471 return mei_cl_is_connected(cldev->cl);
472 }
473 EXPORT_SYMBOL_GPL(mei_cldev_enabled);
474
475 /**
476 * mei_cl_bus_module_get - acquire module of the underlying
477 * hw driver.
478 *
479 * @cldev: mei client device
480 *
481 * Return: true on success; false if the module was removed.
482 */
mei_cl_bus_module_get(struct mei_cl_device * cldev)483 static bool mei_cl_bus_module_get(struct mei_cl_device *cldev)
484 {
485 return try_module_get(cldev->bus->dev->driver->owner);
486 }
487
488 /**
489 * mei_cl_bus_module_put - release the underlying hw module.
490 *
491 * @cldev: mei client device
492 */
mei_cl_bus_module_put(struct mei_cl_device * cldev)493 static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
494 {
495 module_put(cldev->bus->dev->driver->owner);
496 }
497
498 /**
499 * mei_cldev_enable - enable me client device
500 * create connection with me client
501 *
502 * @cldev: me client device
503 *
504 * Return: 0 on success and < 0 on error
505 */
mei_cldev_enable(struct mei_cl_device * cldev)506 int mei_cldev_enable(struct mei_cl_device *cldev)
507 {
508 struct mei_device *bus = cldev->bus;
509 struct mei_cl *cl;
510 int ret;
511
512 cl = cldev->cl;
513
514 mutex_lock(&bus->device_lock);
515 if (cl->state == MEI_FILE_UNINITIALIZED) {
516 ret = mei_cl_link(cl);
517 if (ret)
518 goto out;
519 /* update pointers */
520 cl->cldev = cldev;
521 }
522
523 if (mei_cl_is_connected(cl)) {
524 ret = 0;
525 goto out;
526 }
527
528 if (!mei_me_cl_is_active(cldev->me_cl)) {
529 dev_err(&cldev->dev, "me client is not active\n");
530 ret = -ENOTTY;
531 goto out;
532 }
533
534 ret = mei_cl_connect(cl, cldev->me_cl, NULL);
535 if (ret < 0)
536 dev_err(&cldev->dev, "cannot connect\n");
537
538 out:
539 mutex_unlock(&bus->device_lock);
540
541 return ret;
542 }
543 EXPORT_SYMBOL_GPL(mei_cldev_enable);
544
545 /**
546 * mei_cldev_unregister_callbacks - internal wrapper for unregistering
547 * callbacks.
548 *
549 * @cldev: client device
550 */
mei_cldev_unregister_callbacks(struct mei_cl_device * cldev)551 static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
552 {
553 if (cldev->rx_cb) {
554 cancel_work_sync(&cldev->rx_work);
555 cldev->rx_cb = NULL;
556 }
557
558 if (cldev->notif_cb) {
559 cancel_work_sync(&cldev->notif_work);
560 cldev->notif_cb = NULL;
561 }
562 }
563
564 /**
565 * mei_cldev_disable - disable me client device
566 * disconnect form the me client
567 *
568 * @cldev: me client device
569 *
570 * Return: 0 on success and < 0 on error
571 */
mei_cldev_disable(struct mei_cl_device * cldev)572 int mei_cldev_disable(struct mei_cl_device *cldev)
573 {
574 struct mei_device *bus;
575 struct mei_cl *cl;
576 int err;
577
578 if (!cldev)
579 return -ENODEV;
580
581 cl = cldev->cl;
582
583 bus = cldev->bus;
584
585 mei_cldev_unregister_callbacks(cldev);
586
587 mutex_lock(&bus->device_lock);
588
589 if (!mei_cl_is_connected(cl)) {
590 dev_dbg(bus->dev, "Already disconnected\n");
591 err = 0;
592 goto out;
593 }
594
595 err = mei_cl_disconnect(cl);
596 if (err < 0)
597 dev_err(bus->dev, "Could not disconnect from the ME client\n");
598
599 out:
600 /* Flush queues and remove any pending read */
601 mei_cl_flush_queues(cl, NULL);
602 mei_cl_unlink(cl);
603
604 mutex_unlock(&bus->device_lock);
605 return err;
606 }
607 EXPORT_SYMBOL_GPL(mei_cldev_disable);
608
609 /**
610 * mei_cl_device_find - find matching entry in the driver id table
611 *
612 * @cldev: me client device
613 * @cldrv: me client driver
614 *
615 * Return: id on success; NULL if no id is matching
616 */
617 static const
mei_cl_device_find(struct mei_cl_device * cldev,struct mei_cl_driver * cldrv)618 struct mei_cl_device_id *mei_cl_device_find(struct mei_cl_device *cldev,
619 struct mei_cl_driver *cldrv)
620 {
621 const struct mei_cl_device_id *id;
622 const uuid_le *uuid;
623 u8 version;
624 bool match;
625
626 uuid = mei_me_cl_uuid(cldev->me_cl);
627 version = mei_me_cl_ver(cldev->me_cl);
628
629 id = cldrv->id_table;
630 while (uuid_le_cmp(NULL_UUID_LE, id->uuid)) {
631 if (!uuid_le_cmp(*uuid, id->uuid)) {
632 match = true;
633
634 if (cldev->name[0])
635 if (strncmp(cldev->name, id->name,
636 sizeof(id->name)))
637 match = false;
638
639 if (id->version != MEI_CL_VERSION_ANY)
640 if (id->version != version)
641 match = false;
642 if (match)
643 return id;
644 }
645
646 id++;
647 }
648
649 return NULL;
650 }
651
652 /**
653 * mei_cl_device_match - device match function
654 *
655 * @dev: device
656 * @drv: driver
657 *
658 * Return: 1 if matching device was found 0 otherwise
659 */
mei_cl_device_match(struct device * dev,struct device_driver * drv)660 static int mei_cl_device_match(struct device *dev, struct device_driver *drv)
661 {
662 struct mei_cl_device *cldev = to_mei_cl_device(dev);
663 struct mei_cl_driver *cldrv = to_mei_cl_driver(drv);
664 const struct mei_cl_device_id *found_id;
665
666 if (!cldev)
667 return 0;
668
669 if (!cldev->do_match)
670 return 0;
671
672 if (!cldrv || !cldrv->id_table)
673 return 0;
674
675 found_id = mei_cl_device_find(cldev, cldrv);
676 if (found_id)
677 return 1;
678
679 return 0;
680 }
681
682 /**
683 * mei_cl_device_probe - bus probe function
684 *
685 * @dev: device
686 *
687 * Return: 0 on success; < 0 otherwise
688 */
mei_cl_device_probe(struct device * dev)689 static int mei_cl_device_probe(struct device *dev)
690 {
691 struct mei_cl_device *cldev;
692 struct mei_cl_driver *cldrv;
693 const struct mei_cl_device_id *id;
694 int ret;
695
696 cldev = to_mei_cl_device(dev);
697 cldrv = to_mei_cl_driver(dev->driver);
698
699 if (!cldev)
700 return 0;
701
702 if (!cldrv || !cldrv->probe)
703 return -ENODEV;
704
705 id = mei_cl_device_find(cldev, cldrv);
706 if (!id)
707 return -ENODEV;
708
709 if (!mei_cl_bus_module_get(cldev)) {
710 dev_err(&cldev->dev, "get hw module failed");
711 return -ENODEV;
712 }
713
714 ret = cldrv->probe(cldev, id);
715 if (ret) {
716 mei_cl_bus_module_put(cldev);
717 return ret;
718 }
719
720 __module_get(THIS_MODULE);
721 return 0;
722 }
723
724 /**
725 * mei_cl_device_remove - remove device from the bus
726 *
727 * @dev: device
728 *
729 * Return: 0 on success; < 0 otherwise
730 */
mei_cl_device_remove(struct device * dev)731 static int mei_cl_device_remove(struct device *dev)
732 {
733 struct mei_cl_device *cldev = to_mei_cl_device(dev);
734 struct mei_cl_driver *cldrv;
735 int ret = 0;
736
737 if (!cldev || !dev->driver)
738 return 0;
739
740 cldrv = to_mei_cl_driver(dev->driver);
741 if (cldrv->remove)
742 ret = cldrv->remove(cldev);
743
744 mei_cldev_unregister_callbacks(cldev);
745
746 mei_cl_bus_module_put(cldev);
747 module_put(THIS_MODULE);
748 dev->driver = NULL;
749 return ret;
750
751 }
752
name_show(struct device * dev,struct device_attribute * a,char * buf)753 static ssize_t name_show(struct device *dev, struct device_attribute *a,
754 char *buf)
755 {
756 struct mei_cl_device *cldev = to_mei_cl_device(dev);
757
758 return scnprintf(buf, PAGE_SIZE, "%s", cldev->name);
759 }
760 static DEVICE_ATTR_RO(name);
761
uuid_show(struct device * dev,struct device_attribute * a,char * buf)762 static ssize_t uuid_show(struct device *dev, struct device_attribute *a,
763 char *buf)
764 {
765 struct mei_cl_device *cldev = to_mei_cl_device(dev);
766 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
767
768 return scnprintf(buf, PAGE_SIZE, "%pUl", uuid);
769 }
770 static DEVICE_ATTR_RO(uuid);
771
version_show(struct device * dev,struct device_attribute * a,char * buf)772 static ssize_t version_show(struct device *dev, struct device_attribute *a,
773 char *buf)
774 {
775 struct mei_cl_device *cldev = to_mei_cl_device(dev);
776 u8 version = mei_me_cl_ver(cldev->me_cl);
777
778 return scnprintf(buf, PAGE_SIZE, "%02X", version);
779 }
780 static DEVICE_ATTR_RO(version);
781
modalias_show(struct device * dev,struct device_attribute * a,char * buf)782 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
783 char *buf)
784 {
785 struct mei_cl_device *cldev = to_mei_cl_device(dev);
786 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
787 u8 version = mei_me_cl_ver(cldev->me_cl);
788
789 return scnprintf(buf, PAGE_SIZE, "mei:%s:%pUl:%02X:",
790 cldev->name, uuid, version);
791 }
792 static DEVICE_ATTR_RO(modalias);
793
794 static struct attribute *mei_cldev_attrs[] = {
795 &dev_attr_name.attr,
796 &dev_attr_uuid.attr,
797 &dev_attr_version.attr,
798 &dev_attr_modalias.attr,
799 NULL,
800 };
801 ATTRIBUTE_GROUPS(mei_cldev);
802
803 /**
804 * mei_cl_device_uevent - me client bus uevent handler
805 *
806 * @dev: device
807 * @env: uevent kobject
808 *
809 * Return: 0 on success -ENOMEM on when add_uevent_var fails
810 */
mei_cl_device_uevent(struct device * dev,struct kobj_uevent_env * env)811 static int mei_cl_device_uevent(struct device *dev, struct kobj_uevent_env *env)
812 {
813 struct mei_cl_device *cldev = to_mei_cl_device(dev);
814 const uuid_le *uuid = mei_me_cl_uuid(cldev->me_cl);
815 u8 version = mei_me_cl_ver(cldev->me_cl);
816
817 if (add_uevent_var(env, "MEI_CL_VERSION=%d", version))
818 return -ENOMEM;
819
820 if (add_uevent_var(env, "MEI_CL_UUID=%pUl", uuid))
821 return -ENOMEM;
822
823 if (add_uevent_var(env, "MEI_CL_NAME=%s", cldev->name))
824 return -ENOMEM;
825
826 if (add_uevent_var(env, "MODALIAS=mei:%s:%pUl:%02X:",
827 cldev->name, uuid, version))
828 return -ENOMEM;
829
830 return 0;
831 }
832
833 static struct bus_type mei_cl_bus_type = {
834 .name = "mei",
835 .dev_groups = mei_cldev_groups,
836 .match = mei_cl_device_match,
837 .probe = mei_cl_device_probe,
838 .remove = mei_cl_device_remove,
839 .uevent = mei_cl_device_uevent,
840 };
841
mei_dev_bus_get(struct mei_device * bus)842 static struct mei_device *mei_dev_bus_get(struct mei_device *bus)
843 {
844 if (bus)
845 get_device(bus->dev);
846
847 return bus;
848 }
849
mei_dev_bus_put(struct mei_device * bus)850 static void mei_dev_bus_put(struct mei_device *bus)
851 {
852 if (bus)
853 put_device(bus->dev);
854 }
855
mei_cl_bus_dev_release(struct device * dev)856 static void mei_cl_bus_dev_release(struct device *dev)
857 {
858 struct mei_cl_device *cldev = to_mei_cl_device(dev);
859
860 if (!cldev)
861 return;
862
863 mei_me_cl_put(cldev->me_cl);
864 mei_dev_bus_put(cldev->bus);
865 mei_cl_unlink(cldev->cl);
866 kfree(cldev->cl);
867 kfree(cldev);
868 }
869
870 static const struct device_type mei_cl_device_type = {
871 .release = mei_cl_bus_dev_release,
872 };
873
874 /**
875 * mei_cl_bus_set_name - set device name for me client device
876 *
877 * @cldev: me client device
878 */
mei_cl_bus_set_name(struct mei_cl_device * cldev)879 static inline void mei_cl_bus_set_name(struct mei_cl_device *cldev)
880 {
881 dev_set_name(&cldev->dev, "mei:%s:%pUl:%02X",
882 cldev->name,
883 mei_me_cl_uuid(cldev->me_cl),
884 mei_me_cl_ver(cldev->me_cl));
885 }
886
887 /**
888 * mei_cl_bus_dev_alloc - initialize and allocate mei client device
889 *
890 * @bus: mei device
891 * @me_cl: me client
892 *
893 * Return: allocated device structur or NULL on allocation failure
894 */
mei_cl_bus_dev_alloc(struct mei_device * bus,struct mei_me_client * me_cl)895 static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
896 struct mei_me_client *me_cl)
897 {
898 struct mei_cl_device *cldev;
899 struct mei_cl *cl;
900
901 cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
902 if (!cldev)
903 return NULL;
904
905 cl = mei_cl_allocate(bus);
906 if (!cl) {
907 kfree(cldev);
908 return NULL;
909 }
910
911 device_initialize(&cldev->dev);
912 cldev->dev.parent = bus->dev;
913 cldev->dev.bus = &mei_cl_bus_type;
914 cldev->dev.type = &mei_cl_device_type;
915 cldev->bus = mei_dev_bus_get(bus);
916 cldev->me_cl = mei_me_cl_get(me_cl);
917 cldev->cl = cl;
918 mei_cl_bus_set_name(cldev);
919 cldev->is_added = 0;
920 INIT_LIST_HEAD(&cldev->bus_list);
921
922 return cldev;
923 }
924
925 /**
926 * mei_cl_dev_setup - setup me client device
927 * run fix up routines and set the device name
928 *
929 * @bus: mei device
930 * @cldev: me client device
931 *
932 * Return: true if the device is eligible for enumeration
933 */
mei_cl_bus_dev_setup(struct mei_device * bus,struct mei_cl_device * cldev)934 static bool mei_cl_bus_dev_setup(struct mei_device *bus,
935 struct mei_cl_device *cldev)
936 {
937 cldev->do_match = 1;
938 mei_cl_bus_dev_fixup(cldev);
939
940 /* the device name can change during fix up */
941 if (cldev->do_match)
942 mei_cl_bus_set_name(cldev);
943
944 return cldev->do_match == 1;
945 }
946
947 /**
948 * mei_cl_bus_dev_add - add me client devices
949 *
950 * @cldev: me client device
951 *
952 * Return: 0 on success; < 0 on failre
953 */
mei_cl_bus_dev_add(struct mei_cl_device * cldev)954 static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
955 {
956 int ret;
957
958 dev_dbg(cldev->bus->dev, "adding %pUL:%02X\n",
959 mei_me_cl_uuid(cldev->me_cl),
960 mei_me_cl_ver(cldev->me_cl));
961 ret = device_add(&cldev->dev);
962 if (!ret)
963 cldev->is_added = 1;
964
965 return ret;
966 }
967
968 /**
969 * mei_cl_bus_dev_stop - stop the driver
970 *
971 * @cldev: me client device
972 */
mei_cl_bus_dev_stop(struct mei_cl_device * cldev)973 static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
974 {
975 if (cldev->is_added)
976 device_release_driver(&cldev->dev);
977 }
978
979 /**
980 * mei_cl_bus_dev_destroy - destroy me client devices object
981 *
982 * @cldev: me client device
983 *
984 * Locking: called under "dev->cl_bus_lock" lock
985 */
mei_cl_bus_dev_destroy(struct mei_cl_device * cldev)986 static void mei_cl_bus_dev_destroy(struct mei_cl_device *cldev)
987 {
988
989 WARN_ON(!mutex_is_locked(&cldev->bus->cl_bus_lock));
990
991 if (!cldev->is_added)
992 return;
993
994 device_del(&cldev->dev);
995
996 list_del_init(&cldev->bus_list);
997
998 cldev->is_added = 0;
999 put_device(&cldev->dev);
1000 }
1001
1002 /**
1003 * mei_cl_bus_remove_device - remove a devices form the bus
1004 *
1005 * @cldev: me client device
1006 */
mei_cl_bus_remove_device(struct mei_cl_device * cldev)1007 static void mei_cl_bus_remove_device(struct mei_cl_device *cldev)
1008 {
1009 mei_cl_bus_dev_stop(cldev);
1010 mei_cl_bus_dev_destroy(cldev);
1011 }
1012
1013 /**
1014 * mei_cl_bus_remove_devices - remove all devices form the bus
1015 *
1016 * @bus: mei device
1017 */
mei_cl_bus_remove_devices(struct mei_device * bus)1018 void mei_cl_bus_remove_devices(struct mei_device *bus)
1019 {
1020 struct mei_cl_device *cldev, *next;
1021
1022 mutex_lock(&bus->cl_bus_lock);
1023 list_for_each_entry_safe(cldev, next, &bus->device_list, bus_list)
1024 mei_cl_bus_remove_device(cldev);
1025 mutex_unlock(&bus->cl_bus_lock);
1026 }
1027
1028
1029 /**
1030 * mei_cl_bus_dev_init - allocate and initializes an mei client devices
1031 * based on me client
1032 *
1033 * @bus: mei device
1034 * @me_cl: me client
1035 *
1036 * Locking: called under "dev->cl_bus_lock" lock
1037 */
mei_cl_bus_dev_init(struct mei_device * bus,struct mei_me_client * me_cl)1038 static void mei_cl_bus_dev_init(struct mei_device *bus,
1039 struct mei_me_client *me_cl)
1040 {
1041 struct mei_cl_device *cldev;
1042
1043 WARN_ON(!mutex_is_locked(&bus->cl_bus_lock));
1044
1045 dev_dbg(bus->dev, "initializing %pUl", mei_me_cl_uuid(me_cl));
1046
1047 if (me_cl->bus_added)
1048 return;
1049
1050 cldev = mei_cl_bus_dev_alloc(bus, me_cl);
1051 if (!cldev)
1052 return;
1053
1054 me_cl->bus_added = true;
1055 list_add_tail(&cldev->bus_list, &bus->device_list);
1056
1057 }
1058
1059 /**
1060 * mei_cl_bus_rescan - scan me clients list and add create
1061 * devices for eligible clients
1062 *
1063 * @bus: mei device
1064 */
mei_cl_bus_rescan(struct mei_device * bus)1065 static void mei_cl_bus_rescan(struct mei_device *bus)
1066 {
1067 struct mei_cl_device *cldev, *n;
1068 struct mei_me_client *me_cl;
1069
1070 mutex_lock(&bus->cl_bus_lock);
1071
1072 down_read(&bus->me_clients_rwsem);
1073 list_for_each_entry(me_cl, &bus->me_clients, list)
1074 mei_cl_bus_dev_init(bus, me_cl);
1075 up_read(&bus->me_clients_rwsem);
1076
1077 list_for_each_entry_safe(cldev, n, &bus->device_list, bus_list) {
1078
1079 if (!mei_me_cl_is_active(cldev->me_cl)) {
1080 mei_cl_bus_remove_device(cldev);
1081 continue;
1082 }
1083
1084 if (cldev->is_added)
1085 continue;
1086
1087 if (mei_cl_bus_dev_setup(bus, cldev))
1088 mei_cl_bus_dev_add(cldev);
1089 else {
1090 list_del_init(&cldev->bus_list);
1091 put_device(&cldev->dev);
1092 }
1093 }
1094 mutex_unlock(&bus->cl_bus_lock);
1095
1096 dev_dbg(bus->dev, "rescan end");
1097 }
1098
mei_cl_bus_rescan_work(struct work_struct * work)1099 void mei_cl_bus_rescan_work(struct work_struct *work)
1100 {
1101 struct mei_device *bus =
1102 container_of(work, struct mei_device, bus_rescan_work);
1103
1104 mei_cl_bus_rescan(bus);
1105 }
1106
__mei_cldev_driver_register(struct mei_cl_driver * cldrv,struct module * owner)1107 int __mei_cldev_driver_register(struct mei_cl_driver *cldrv,
1108 struct module *owner)
1109 {
1110 int err;
1111
1112 cldrv->driver.name = cldrv->name;
1113 cldrv->driver.owner = owner;
1114 cldrv->driver.bus = &mei_cl_bus_type;
1115
1116 err = driver_register(&cldrv->driver);
1117 if (err)
1118 return err;
1119
1120 pr_debug("mei: driver [%s] registered\n", cldrv->driver.name);
1121
1122 return 0;
1123 }
1124 EXPORT_SYMBOL_GPL(__mei_cldev_driver_register);
1125
mei_cldev_driver_unregister(struct mei_cl_driver * cldrv)1126 void mei_cldev_driver_unregister(struct mei_cl_driver *cldrv)
1127 {
1128 driver_unregister(&cldrv->driver);
1129
1130 pr_debug("mei: driver [%s] unregistered\n", cldrv->driver.name);
1131 }
1132 EXPORT_SYMBOL_GPL(mei_cldev_driver_unregister);
1133
1134
mei_cl_bus_init(void)1135 int __init mei_cl_bus_init(void)
1136 {
1137 return bus_register(&mei_cl_bus_type);
1138 }
1139
mei_cl_bus_exit(void)1140 void __exit mei_cl_bus_exit(void)
1141 {
1142 bus_unregister(&mei_cl_bus_type);
1143 }
1144
