xref: /openbmc/linux/drivers/misc/mei/client.c (revision 0da85d1e)
1 /*
2  *
3  * Intel Management Engine Interface (Intel MEI) Linux driver
4  * Copyright (c) 2003-2012, Intel Corporation.
5  *
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.
9  *
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
13  * more details.
14  *
15  */
16 
17 #include <linux/sched.h>
18 #include <linux/wait.h>
19 #include <linux/delay.h>
20 #include <linux/slab.h>
21 #include <linux/pm_runtime.h>
22 
23 #include <linux/mei.h>
24 
25 #include "mei_dev.h"
26 #include "hbm.h"
27 #include "client.h"
28 
29 /**
30  * mei_me_cl_init - initialize me client
31  *
32  * @me_cl: me client
33  */
34 void mei_me_cl_init(struct mei_me_client *me_cl)
35 {
36 	INIT_LIST_HEAD(&me_cl->list);
37 	kref_init(&me_cl->refcnt);
38 }
39 
40 /**
41  * mei_me_cl_get - increases me client refcount
42  *
43  * @me_cl: me client
44  *
45  * Locking: called under "dev->device_lock" lock
46  *
47  * Return: me client or NULL
48  */
49 struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl)
50 {
51 	if (me_cl && kref_get_unless_zero(&me_cl->refcnt))
52 		return me_cl;
53 
54 	return NULL;
55 }
56 
57 /**
58  * mei_me_cl_release - free me client
59  *
60  * Locking: called under "dev->device_lock" lock
61  *
62  * @ref: me_client refcount
63  */
64 static void mei_me_cl_release(struct kref *ref)
65 {
66 	struct mei_me_client *me_cl =
67 		container_of(ref, struct mei_me_client, refcnt);
68 
69 	kfree(me_cl);
70 }
71 
72 /**
73  * mei_me_cl_put - decrease me client refcount and free client if necessary
74  *
75  * Locking: called under "dev->device_lock" lock
76  *
77  * @me_cl: me client
78  */
79 void mei_me_cl_put(struct mei_me_client *me_cl)
80 {
81 	if (me_cl)
82 		kref_put(&me_cl->refcnt, mei_me_cl_release);
83 }
84 
85 /**
86  * __mei_me_cl_del  - delete me client form the list and decrease
87  *     reference counter
88  *
89  * @dev: mei device
90  * @me_cl: me client
91  *
92  * Locking: dev->me_clients_rwsem
93  */
94 static void __mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
95 {
96 	if (!me_cl)
97 		return;
98 
99 	list_del(&me_cl->list);
100 	mei_me_cl_put(me_cl);
101 }
102 
103 /**
104  * mei_me_cl_add - add me client to the list
105  *
106  * @dev: mei device
107  * @me_cl: me client
108  */
109 void mei_me_cl_add(struct mei_device *dev, struct mei_me_client *me_cl)
110 {
111 	down_write(&dev->me_clients_rwsem);
112 	list_add(&me_cl->list, &dev->me_clients);
113 	up_write(&dev->me_clients_rwsem);
114 }
115 
116 /**
117  * __mei_me_cl_by_uuid - locate me client by uuid
118  *	increases ref count
119  *
120  * @dev: mei device
121  * @uuid: me client uuid
122  *
123  * Return: me client or NULL if not found
124  *
125  * Locking: dev->me_clients_rwsem
126  */
127 static struct mei_me_client *__mei_me_cl_by_uuid(struct mei_device *dev,
128 					const uuid_le *uuid)
129 {
130 	struct mei_me_client *me_cl;
131 	const uuid_le *pn;
132 
133 	WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
134 
135 	list_for_each_entry(me_cl, &dev->me_clients, list) {
136 		pn = &me_cl->props.protocol_name;
137 		if (uuid_le_cmp(*uuid, *pn) == 0)
138 			return mei_me_cl_get(me_cl);
139 	}
140 
141 	return NULL;
142 }
143 
144 /**
145  * mei_me_cl_by_uuid - locate me client by uuid
146  *	increases ref count
147  *
148  * @dev: mei device
149  * @uuid: me client uuid
150  *
151  * Return: me client or NULL if not found
152  *
153  * Locking: dev->me_clients_rwsem
154  */
155 struct mei_me_client *mei_me_cl_by_uuid(struct mei_device *dev,
156 					const uuid_le *uuid)
157 {
158 	struct mei_me_client *me_cl;
159 
160 	down_read(&dev->me_clients_rwsem);
161 	me_cl = __mei_me_cl_by_uuid(dev, uuid);
162 	up_read(&dev->me_clients_rwsem);
163 
164 	return me_cl;
165 }
166 
167 /**
168  * mei_me_cl_by_id - locate me client by client id
169  *	increases ref count
170  *
171  * @dev: the device structure
172  * @client_id: me client id
173  *
174  * Return: me client or NULL if not found
175  *
176  * Locking: dev->me_clients_rwsem
177  */
178 struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
179 {
180 
181 	struct mei_me_client *__me_cl, *me_cl = NULL;
182 
183 	down_read(&dev->me_clients_rwsem);
184 	list_for_each_entry(__me_cl, &dev->me_clients, list) {
185 		if (__me_cl->client_id == client_id) {
186 			me_cl = mei_me_cl_get(__me_cl);
187 			break;
188 		}
189 	}
190 	up_read(&dev->me_clients_rwsem);
191 
192 	return me_cl;
193 }
194 
195 /**
196  * __mei_me_cl_by_uuid_id - locate me client by client id and uuid
197  *	increases ref count
198  *
199  * @dev: the device structure
200  * @uuid: me client uuid
201  * @client_id: me client id
202  *
203  * Return: me client or null if not found
204  *
205  * Locking: dev->me_clients_rwsem
206  */
207 static struct mei_me_client *__mei_me_cl_by_uuid_id(struct mei_device *dev,
208 					   const uuid_le *uuid, u8 client_id)
209 {
210 	struct mei_me_client *me_cl;
211 	const uuid_le *pn;
212 
213 	WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
214 
215 	list_for_each_entry(me_cl, &dev->me_clients, list) {
216 		pn = &me_cl->props.protocol_name;
217 		if (uuid_le_cmp(*uuid, *pn) == 0 &&
218 		    me_cl->client_id == client_id)
219 			return mei_me_cl_get(me_cl);
220 	}
221 
222 	return NULL;
223 }
224 
225 
226 /**
227  * mei_me_cl_by_uuid_id - locate me client by client id and uuid
228  *	increases ref count
229  *
230  * @dev: the device structure
231  * @uuid: me client uuid
232  * @client_id: me client id
233  *
234  * Return: me client or null if not found
235  */
236 struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev,
237 					   const uuid_le *uuid, u8 client_id)
238 {
239 	struct mei_me_client *me_cl;
240 
241 	down_read(&dev->me_clients_rwsem);
242 	me_cl = __mei_me_cl_by_uuid_id(dev, uuid, client_id);
243 	up_read(&dev->me_clients_rwsem);
244 
245 	return me_cl;
246 }
247 
248 /**
249  * mei_me_cl_rm_by_uuid - remove all me clients matching uuid
250  *
251  * @dev: the device structure
252  * @uuid: me client uuid
253  *
254  * Locking: called under "dev->device_lock" lock
255  */
256 void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)
257 {
258 	struct mei_me_client *me_cl;
259 
260 	dev_dbg(dev->dev, "remove %pUl\n", uuid);
261 
262 	down_write(&dev->me_clients_rwsem);
263 	me_cl = __mei_me_cl_by_uuid(dev, uuid);
264 	__mei_me_cl_del(dev, me_cl);
265 	up_write(&dev->me_clients_rwsem);
266 }
267 
268 /**
269  * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id
270  *
271  * @dev: the device structure
272  * @uuid: me client uuid
273  * @id: me client id
274  *
275  * Locking: called under "dev->device_lock" lock
276  */
277 void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)
278 {
279 	struct mei_me_client *me_cl;
280 
281 	dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);
282 
283 	down_write(&dev->me_clients_rwsem);
284 	me_cl = __mei_me_cl_by_uuid_id(dev, uuid, id);
285 	__mei_me_cl_del(dev, me_cl);
286 	up_write(&dev->me_clients_rwsem);
287 }
288 
289 /**
290  * mei_me_cl_rm_all - remove all me clients
291  *
292  * @dev: the device structure
293  *
294  * Locking: called under "dev->device_lock" lock
295  */
296 void mei_me_cl_rm_all(struct mei_device *dev)
297 {
298 	struct mei_me_client *me_cl, *next;
299 
300 	down_write(&dev->me_clients_rwsem);
301 	list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
302 		__mei_me_cl_del(dev, me_cl);
303 	up_write(&dev->me_clients_rwsem);
304 }
305 
306 /**
307  * mei_cl_cmp_id - tells if the clients are the same
308  *
309  * @cl1: host client 1
310  * @cl2: host client 2
311  *
312  * Return: true  - if the clients has same host and me ids
313  *         false - otherwise
314  */
315 static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
316 				const struct mei_cl *cl2)
317 {
318 	return cl1 && cl2 &&
319 		(cl1->host_client_id == cl2->host_client_id) &&
320 		(cl1->me_client_id == cl2->me_client_id);
321 }
322 
323 /**
324  * mei_io_cb_free - free mei_cb_private related memory
325  *
326  * @cb: mei callback struct
327  */
328 void mei_io_cb_free(struct mei_cl_cb *cb)
329 {
330 	if (cb == NULL)
331 		return;
332 
333 	list_del(&cb->list);
334 	kfree(cb->buf.data);
335 	kfree(cb);
336 }
337 
338 /**
339  * mei_io_cb_init - allocate and initialize io callback
340  *
341  * @cl: mei client
342  * @type: operation type
343  * @fp: pointer to file structure
344  *
345  * Return: mei_cl_cb pointer or NULL;
346  */
347 struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, enum mei_cb_file_ops type,
348 				 struct file *fp)
349 {
350 	struct mei_cl_cb *cb;
351 
352 	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
353 	if (!cb)
354 		return NULL;
355 
356 	INIT_LIST_HEAD(&cb->list);
357 	cb->file_object = fp;
358 	cb->cl = cl;
359 	cb->buf_idx = 0;
360 	cb->fop_type = type;
361 	return cb;
362 }
363 
364 /**
365  * __mei_io_list_flush - removes and frees cbs belonging to cl.
366  *
367  * @list:  an instance of our list structure
368  * @cl:    host client, can be NULL for flushing the whole list
369  * @free:  whether to free the cbs
370  */
371 static void __mei_io_list_flush(struct mei_cl_cb *list,
372 				struct mei_cl *cl, bool free)
373 {
374 	struct mei_cl_cb *cb, *next;
375 
376 	/* enable removing everything if no cl is specified */
377 	list_for_each_entry_safe(cb, next, &list->list, list) {
378 		if (!cl || mei_cl_cmp_id(cl, cb->cl)) {
379 			list_del_init(&cb->list);
380 			if (free)
381 				mei_io_cb_free(cb);
382 		}
383 	}
384 }
385 
386 /**
387  * mei_io_list_flush - removes list entry belonging to cl.
388  *
389  * @list:  An instance of our list structure
390  * @cl: host client
391  */
392 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
393 {
394 	__mei_io_list_flush(list, cl, false);
395 }
396 
397 /**
398  * mei_io_list_free - removes cb belonging to cl and free them
399  *
400  * @list:  An instance of our list structure
401  * @cl: host client
402  */
403 static inline void mei_io_list_free(struct mei_cl_cb *list, struct mei_cl *cl)
404 {
405 	__mei_io_list_flush(list, cl, true);
406 }
407 
408 /**
409  * mei_io_cb_alloc_buf - allocate callback buffer
410  *
411  * @cb: io callback structure
412  * @length: size of the buffer
413  *
414  * Return: 0 on success
415  *         -EINVAL if cb is NULL
416  *         -ENOMEM if allocation failed
417  */
418 int mei_io_cb_alloc_buf(struct mei_cl_cb *cb, size_t length)
419 {
420 	if (!cb)
421 		return -EINVAL;
422 
423 	if (length == 0)
424 		return 0;
425 
426 	cb->buf.data = kmalloc(length, GFP_KERNEL);
427 	if (!cb->buf.data)
428 		return -ENOMEM;
429 	cb->buf.size = length;
430 	return 0;
431 }
432 
433 /**
434  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
435  *
436  * @cl: host client
437  * @length: size of the buffer
438  * @type: operation type
439  * @fp: associated file pointer (might be NULL)
440  *
441  * Return: cb on success and NULL on failure
442  */
443 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
444 				  enum mei_cb_file_ops type, struct file *fp)
445 {
446 	struct mei_cl_cb *cb;
447 
448 	cb = mei_io_cb_init(cl, type, fp);
449 	if (!cb)
450 		return NULL;
451 
452 	if (mei_io_cb_alloc_buf(cb, length)) {
453 		mei_io_cb_free(cb);
454 		return NULL;
455 	}
456 
457 	return cb;
458 }
459 
460 /**
461  * mei_cl_read_cb - find this cl's callback in the read list
462  *     for a specific file
463  *
464  * @cl: host client
465  * @fp: file pointer (matching cb file object), may be NULL
466  *
467  * Return: cb on success, NULL if cb is not found
468  */
469 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
470 {
471 	struct mei_cl_cb *cb;
472 
473 	list_for_each_entry(cb, &cl->rd_completed, list)
474 		if (!fp || fp == cb->file_object)
475 			return cb;
476 
477 	return NULL;
478 }
479 
480 /**
481  * mei_cl_read_cb_flush - free client's read pending and completed cbs
482  *   for a specific file
483  *
484  * @cl: host client
485  * @fp: file pointer (matching cb file object), may be NULL
486  */
487 void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp)
488 {
489 	struct mei_cl_cb *cb, *next;
490 
491 	list_for_each_entry_safe(cb, next, &cl->rd_completed, list)
492 		if (!fp || fp == cb->file_object)
493 			mei_io_cb_free(cb);
494 
495 
496 	list_for_each_entry_safe(cb, next, &cl->rd_pending, list)
497 		if (!fp || fp == cb->file_object)
498 			mei_io_cb_free(cb);
499 }
500 
501 /**
502  * mei_cl_flush_queues - flushes queue lists belonging to cl.
503  *
504  * @cl: host client
505  * @fp: file pointer (matching cb file object), may be NULL
506  *
507  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
508  */
509 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
510 {
511 	struct mei_device *dev;
512 
513 	if (WARN_ON(!cl || !cl->dev))
514 		return -EINVAL;
515 
516 	dev = cl->dev;
517 
518 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
519 	mei_io_list_free(&cl->dev->write_list, cl);
520 	mei_io_list_free(&cl->dev->write_waiting_list, cl);
521 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
522 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
523 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
524 	mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
525 
526 	mei_cl_read_cb_flush(cl, fp);
527 
528 	return 0;
529 }
530 
531 
532 /**
533  * mei_cl_init - initializes cl.
534  *
535  * @cl: host client to be initialized
536  * @dev: mei device
537  */
538 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
539 {
540 	memset(cl, 0, sizeof(struct mei_cl));
541 	init_waitqueue_head(&cl->wait);
542 	init_waitqueue_head(&cl->rx_wait);
543 	init_waitqueue_head(&cl->tx_wait);
544 	INIT_LIST_HEAD(&cl->rd_completed);
545 	INIT_LIST_HEAD(&cl->rd_pending);
546 	INIT_LIST_HEAD(&cl->link);
547 	INIT_LIST_HEAD(&cl->device_link);
548 	cl->writing_state = MEI_IDLE;
549 	cl->dev = dev;
550 }
551 
552 /**
553  * mei_cl_allocate - allocates cl  structure and sets it up.
554  *
555  * @dev: mei device
556  * Return:  The allocated file or NULL on failure
557  */
558 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
559 {
560 	struct mei_cl *cl;
561 
562 	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
563 	if (!cl)
564 		return NULL;
565 
566 	mei_cl_init(cl, dev);
567 
568 	return cl;
569 }
570 
571 /**
572  * mei_cl_link - allocate host id in the host map
573  *
574  * @cl: host client
575  * @id: fixed host id or MEI_HOST_CLIENT_ID_ANY (-1) for generic one
576  *
577  * Return: 0 on success
578  *	-EINVAL on incorrect values
579  *	-EMFILE if open count exceeded.
580  */
581 int mei_cl_link(struct mei_cl *cl, int id)
582 {
583 	struct mei_device *dev;
584 	long open_handle_count;
585 
586 	if (WARN_ON(!cl || !cl->dev))
587 		return -EINVAL;
588 
589 	dev = cl->dev;
590 
591 	/* If Id is not assigned get one*/
592 	if (id == MEI_HOST_CLIENT_ID_ANY)
593 		id = find_first_zero_bit(dev->host_clients_map,
594 					MEI_CLIENTS_MAX);
595 
596 	if (id >= MEI_CLIENTS_MAX) {
597 		dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
598 		return -EMFILE;
599 	}
600 
601 	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
602 	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
603 		dev_err(dev->dev, "open_handle_count exceeded %d",
604 			MEI_MAX_OPEN_HANDLE_COUNT);
605 		return -EMFILE;
606 	}
607 
608 	dev->open_handle_count++;
609 
610 	cl->host_client_id = id;
611 	list_add_tail(&cl->link, &dev->file_list);
612 
613 	set_bit(id, dev->host_clients_map);
614 
615 	cl->state = MEI_FILE_INITIALIZING;
616 
617 	cl_dbg(dev, cl, "link cl\n");
618 	return 0;
619 }
620 
621 /**
622  * mei_cl_unlink - remove me_cl from the list
623  *
624  * @cl: host client
625  *
626  * Return: always 0
627  */
628 int mei_cl_unlink(struct mei_cl *cl)
629 {
630 	struct mei_device *dev;
631 
632 	/* don't shout on error exit path */
633 	if (!cl)
634 		return 0;
635 
636 	/* wd and amthif might not be initialized */
637 	if (!cl->dev)
638 		return 0;
639 
640 	dev = cl->dev;
641 
642 	cl_dbg(dev, cl, "unlink client");
643 
644 	if (dev->open_handle_count > 0)
645 		dev->open_handle_count--;
646 
647 	/* never clear the 0 bit */
648 	if (cl->host_client_id)
649 		clear_bit(cl->host_client_id, dev->host_clients_map);
650 
651 	list_del_init(&cl->link);
652 
653 	cl->state = MEI_FILE_INITIALIZING;
654 
655 	return 0;
656 }
657 
658 
659 void mei_host_client_init(struct work_struct *work)
660 {
661 	struct mei_device *dev =
662 		container_of(work, struct mei_device, init_work);
663 	struct mei_me_client *me_cl;
664 
665 	mutex_lock(&dev->device_lock);
666 
667 
668 	me_cl = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
669 	if (me_cl)
670 		mei_amthif_host_init(dev);
671 	mei_me_cl_put(me_cl);
672 
673 	me_cl = mei_me_cl_by_uuid(dev, &mei_wd_guid);
674 	if (me_cl)
675 		mei_wd_host_init(dev);
676 	mei_me_cl_put(me_cl);
677 
678 	me_cl = mei_me_cl_by_uuid(dev, &mei_nfc_guid);
679 	if (me_cl)
680 		mei_nfc_host_init(dev);
681 	mei_me_cl_put(me_cl);
682 
683 
684 	dev->dev_state = MEI_DEV_ENABLED;
685 	dev->reset_count = 0;
686 	mutex_unlock(&dev->device_lock);
687 
688 	pm_runtime_mark_last_busy(dev->dev);
689 	dev_dbg(dev->dev, "rpm: autosuspend\n");
690 	pm_runtime_autosuspend(dev->dev);
691 }
692 
693 /**
694  * mei_hbuf_acquire - try to acquire host buffer
695  *
696  * @dev: the device structure
697  * Return: true if host buffer was acquired
698  */
699 bool mei_hbuf_acquire(struct mei_device *dev)
700 {
701 	if (mei_pg_state(dev) == MEI_PG_ON ||
702 	    dev->pg_event == MEI_PG_EVENT_WAIT) {
703 		dev_dbg(dev->dev, "device is in pg\n");
704 		return false;
705 	}
706 
707 	if (!dev->hbuf_is_ready) {
708 		dev_dbg(dev->dev, "hbuf is not ready\n");
709 		return false;
710 	}
711 
712 	dev->hbuf_is_ready = false;
713 
714 	return true;
715 }
716 
717 /**
718  * mei_cl_disconnect - disconnect host client from the me one
719  *
720  * @cl: host client
721  *
722  * Locking: called under "dev->device_lock" lock
723  *
724  * Return: 0 on success, <0 on failure.
725  */
726 int mei_cl_disconnect(struct mei_cl *cl)
727 {
728 	struct mei_device *dev;
729 	struct mei_cl_cb *cb;
730 	int rets;
731 
732 	if (WARN_ON(!cl || !cl->dev))
733 		return -ENODEV;
734 
735 	dev = cl->dev;
736 
737 	cl_dbg(dev, cl, "disconnecting");
738 
739 	if (cl->state != MEI_FILE_DISCONNECTING)
740 		return 0;
741 
742 	rets = pm_runtime_get(dev->dev);
743 	if (rets < 0 && rets != -EINPROGRESS) {
744 		pm_runtime_put_noidle(dev->dev);
745 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
746 		return rets;
747 	}
748 
749 	cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT, NULL);
750 	rets = cb ? 0 : -ENOMEM;
751 	if (rets)
752 		goto free;
753 
754 	if (mei_hbuf_acquire(dev)) {
755 		if (mei_hbm_cl_disconnect_req(dev, cl)) {
756 			rets = -ENODEV;
757 			cl_err(dev, cl, "failed to disconnect.\n");
758 			goto free;
759 		}
760 		cl->timer_count = MEI_CONNECT_TIMEOUT;
761 		mdelay(10); /* Wait for hardware disconnection ready */
762 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
763 	} else {
764 		cl_dbg(dev, cl, "add disconnect cb to control write list\n");
765 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
766 
767 	}
768 	mutex_unlock(&dev->device_lock);
769 
770 	wait_event_timeout(cl->wait,
771 			MEI_FILE_DISCONNECTED == cl->state,
772 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
773 
774 	mutex_lock(&dev->device_lock);
775 
776 	if (MEI_FILE_DISCONNECTED == cl->state) {
777 		rets = 0;
778 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
779 	} else {
780 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
781 		rets = -ETIME;
782 	}
783 
784 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
785 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
786 free:
787 	cl_dbg(dev, cl, "rpm: autosuspend\n");
788 	pm_runtime_mark_last_busy(dev->dev);
789 	pm_runtime_put_autosuspend(dev->dev);
790 
791 	mei_io_cb_free(cb);
792 	return rets;
793 }
794 
795 
796 /**
797  * mei_cl_is_other_connecting - checks if other
798  *    client with the same me client id is connecting
799  *
800  * @cl: private data of the file object
801  *
802  * Return: true if other client is connected, false - otherwise.
803  */
804 bool mei_cl_is_other_connecting(struct mei_cl *cl)
805 {
806 	struct mei_device *dev;
807 	struct mei_cl *ocl; /* the other client */
808 
809 	if (WARN_ON(!cl || !cl->dev))
810 		return false;
811 
812 	dev = cl->dev;
813 
814 	list_for_each_entry(ocl, &dev->file_list, link) {
815 		if (ocl->state == MEI_FILE_CONNECTING &&
816 		    ocl != cl &&
817 		    cl->me_client_id == ocl->me_client_id)
818 			return true;
819 
820 	}
821 
822 	return false;
823 }
824 
825 /**
826  * mei_cl_connect - connect host client to the me one
827  *
828  * @cl: host client
829  * @file: pointer to file structure
830  *
831  * Locking: called under "dev->device_lock" lock
832  *
833  * Return: 0 on success, <0 on failure.
834  */
835 int mei_cl_connect(struct mei_cl *cl, struct file *file)
836 {
837 	struct mei_device *dev;
838 	struct mei_cl_cb *cb;
839 	int rets;
840 
841 	if (WARN_ON(!cl || !cl->dev))
842 		return -ENODEV;
843 
844 	dev = cl->dev;
845 
846 	rets = pm_runtime_get(dev->dev);
847 	if (rets < 0 && rets != -EINPROGRESS) {
848 		pm_runtime_put_noidle(dev->dev);
849 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
850 		return rets;
851 	}
852 
853 	cb = mei_io_cb_init(cl, MEI_FOP_CONNECT, file);
854 	rets = cb ? 0 : -ENOMEM;
855 	if (rets)
856 		goto out;
857 
858 	/* run hbuf acquire last so we don't have to undo */
859 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
860 		cl->state = MEI_FILE_CONNECTING;
861 		if (mei_hbm_cl_connect_req(dev, cl)) {
862 			rets = -ENODEV;
863 			goto out;
864 		}
865 		cl->timer_count = MEI_CONNECT_TIMEOUT;
866 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
867 	} else {
868 		cl->state = MEI_FILE_INITIALIZING;
869 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
870 	}
871 
872 	mutex_unlock(&dev->device_lock);
873 	wait_event_timeout(cl->wait,
874 			(cl->state == MEI_FILE_CONNECTED ||
875 			 cl->state == MEI_FILE_DISCONNECTED),
876 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
877 	mutex_lock(&dev->device_lock);
878 
879 	if (!mei_cl_is_connected(cl)) {
880 		cl->state = MEI_FILE_DISCONNECTED;
881 		/* something went really wrong */
882 		if (!cl->status)
883 			cl->status = -EFAULT;
884 
885 		mei_io_list_flush(&dev->ctrl_rd_list, cl);
886 		mei_io_list_flush(&dev->ctrl_wr_list, cl);
887 	}
888 
889 	rets = cl->status;
890 
891 out:
892 	cl_dbg(dev, cl, "rpm: autosuspend\n");
893 	pm_runtime_mark_last_busy(dev->dev);
894 	pm_runtime_put_autosuspend(dev->dev);
895 
896 	mei_io_cb_free(cb);
897 	return rets;
898 }
899 
900 /**
901  * mei_cl_alloc_linked - allocate and link host client
902  *
903  * @dev: the device structure
904  * @id: fixed host id or MEI_HOST_CLIENT_ID_ANY (-1) for generic one
905  *
906  * Return: cl on success ERR_PTR on failure
907  */
908 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev, int id)
909 {
910 	struct mei_cl *cl;
911 	int ret;
912 
913 	cl = mei_cl_allocate(dev);
914 	if (!cl) {
915 		ret = -ENOMEM;
916 		goto err;
917 	}
918 
919 	ret = mei_cl_link(cl, id);
920 	if (ret)
921 		goto err;
922 
923 	return cl;
924 err:
925 	kfree(cl);
926 	return ERR_PTR(ret);
927 }
928 
929 
930 
931 /**
932  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
933  *
934  * @cl: private data of the file object
935  *
936  * Return: 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
937  *	-ENOENT if mei_cl is not present
938  *	-EINVAL if single_recv_buf == 0
939  */
940 int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
941 {
942 	struct mei_device *dev;
943 	struct mei_me_client *me_cl;
944 	int rets = 0;
945 
946 	if (WARN_ON(!cl || !cl->dev))
947 		return -EINVAL;
948 
949 	dev = cl->dev;
950 
951 	if (cl->mei_flow_ctrl_creds > 0)
952 		return 1;
953 
954 	me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);
955 	if (!me_cl) {
956 		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
957 		return -ENOENT;
958 	}
959 
960 	if (me_cl->mei_flow_ctrl_creds > 0) {
961 		rets = 1;
962 		if (WARN_ON(me_cl->props.single_recv_buf == 0))
963 			rets = -EINVAL;
964 	}
965 	mei_me_cl_put(me_cl);
966 	return rets;
967 }
968 
969 /**
970  * mei_cl_flow_ctrl_reduce - reduces flow_control.
971  *
972  * @cl: private data of the file object
973  *
974  * Return:
975  *	0 on success
976  *	-ENOENT when me client is not found
977  *	-EINVAL when ctrl credits are <= 0
978  */
979 int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
980 {
981 	struct mei_device *dev;
982 	struct mei_me_client *me_cl;
983 	int rets;
984 
985 	if (WARN_ON(!cl || !cl->dev))
986 		return -EINVAL;
987 
988 	dev = cl->dev;
989 
990 	me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);
991 	if (!me_cl) {
992 		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
993 		return -ENOENT;
994 	}
995 
996 	if (me_cl->props.single_recv_buf) {
997 		if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0)) {
998 			rets = -EINVAL;
999 			goto out;
1000 		}
1001 		me_cl->mei_flow_ctrl_creds--;
1002 	} else {
1003 		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0)) {
1004 			rets = -EINVAL;
1005 			goto out;
1006 		}
1007 		cl->mei_flow_ctrl_creds--;
1008 	}
1009 	rets = 0;
1010 out:
1011 	mei_me_cl_put(me_cl);
1012 	return rets;
1013 }
1014 
1015 /**
1016  * mei_cl_read_start - the start read client message function.
1017  *
1018  * @cl: host client
1019  * @length: number of bytes to read
1020  * @fp: pointer to file structure
1021  *
1022  * Return: 0 on success, <0 on failure.
1023  */
1024 int mei_cl_read_start(struct mei_cl *cl, size_t length, struct file *fp)
1025 {
1026 	struct mei_device *dev;
1027 	struct mei_cl_cb *cb;
1028 	struct mei_me_client *me_cl;
1029 	int rets;
1030 
1031 	if (WARN_ON(!cl || !cl->dev))
1032 		return -ENODEV;
1033 
1034 	dev = cl->dev;
1035 
1036 	if (!mei_cl_is_connected(cl))
1037 		return -ENODEV;
1038 
1039 	/* HW currently supports only one pending read */
1040 	if (!list_empty(&cl->rd_pending))
1041 		return -EBUSY;
1042 
1043 	me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id);
1044 	if (!me_cl) {
1045 		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
1046 		return  -ENOTTY;
1047 	}
1048 	/* always allocate at least client max message */
1049 	length = max_t(size_t, length, me_cl->props.max_msg_length);
1050 	mei_me_cl_put(me_cl);
1051 
1052 	rets = pm_runtime_get(dev->dev);
1053 	if (rets < 0 && rets != -EINPROGRESS) {
1054 		pm_runtime_put_noidle(dev->dev);
1055 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1056 		return rets;
1057 	}
1058 
1059 	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_READ, fp);
1060 	rets = cb ? 0 : -ENOMEM;
1061 	if (rets)
1062 		goto out;
1063 
1064 	if (mei_hbuf_acquire(dev)) {
1065 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1066 		if (rets < 0)
1067 			goto out;
1068 
1069 		list_add_tail(&cb->list, &cl->rd_pending);
1070 	} else {
1071 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1072 	}
1073 
1074 out:
1075 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1076 	pm_runtime_mark_last_busy(dev->dev);
1077 	pm_runtime_put_autosuspend(dev->dev);
1078 
1079 	if (rets)
1080 		mei_io_cb_free(cb);
1081 
1082 	return rets;
1083 }
1084 
1085 /**
1086  * mei_cl_irq_write - write a message to device
1087  *	from the interrupt thread context
1088  *
1089  * @cl: client
1090  * @cb: callback block.
1091  * @cmpl_list: complete list.
1092  *
1093  * Return: 0, OK; otherwise error.
1094  */
1095 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1096 		     struct mei_cl_cb *cmpl_list)
1097 {
1098 	struct mei_device *dev;
1099 	struct mei_msg_data *buf;
1100 	struct mei_msg_hdr mei_hdr;
1101 	size_t len;
1102 	u32 msg_slots;
1103 	int slots;
1104 	int rets;
1105 
1106 	if (WARN_ON(!cl || !cl->dev))
1107 		return -ENODEV;
1108 
1109 	dev = cl->dev;
1110 
1111 	buf = &cb->buf;
1112 
1113 	rets = mei_cl_flow_ctrl_creds(cl);
1114 	if (rets < 0)
1115 		return rets;
1116 
1117 	if (rets == 0) {
1118 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1119 		return 0;
1120 	}
1121 
1122 	slots = mei_hbuf_empty_slots(dev);
1123 	len = buf->size - cb->buf_idx;
1124 	msg_slots = mei_data2slots(len);
1125 
1126 	mei_hdr.host_addr = cl->host_client_id;
1127 	mei_hdr.me_addr = cl->me_client_id;
1128 	mei_hdr.reserved = 0;
1129 	mei_hdr.internal = cb->internal;
1130 
1131 	if (slots >= msg_slots) {
1132 		mei_hdr.length = len;
1133 		mei_hdr.msg_complete = 1;
1134 	/* Split the message only if we can write the whole host buffer */
1135 	} else if (slots == dev->hbuf_depth) {
1136 		msg_slots = slots;
1137 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1138 		mei_hdr.length = len;
1139 		mei_hdr.msg_complete = 0;
1140 	} else {
1141 		/* wait for next time the host buffer is empty */
1142 		return 0;
1143 	}
1144 
1145 	cl_dbg(dev, cl, "buf: size = %d idx = %lu\n",
1146 			cb->buf.size, cb->buf_idx);
1147 
1148 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1149 	if (rets) {
1150 		cl->status = rets;
1151 		list_move_tail(&cb->list, &cmpl_list->list);
1152 		return rets;
1153 	}
1154 
1155 	cl->status = 0;
1156 	cl->writing_state = MEI_WRITING;
1157 	cb->buf_idx += mei_hdr.length;
1158 	cb->completed = mei_hdr.msg_complete == 1;
1159 
1160 	if (mei_hdr.msg_complete) {
1161 		if (mei_cl_flow_ctrl_reduce(cl))
1162 			return -EIO;
1163 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
1164 	}
1165 
1166 	return 0;
1167 }
1168 
1169 /**
1170  * mei_cl_write - submit a write cb to mei device
1171  *	assumes device_lock is locked
1172  *
1173  * @cl: host client
1174  * @cb: write callback with filled data
1175  * @blocking: block until completed
1176  *
1177  * Return: number of bytes sent on success, <0 on failure.
1178  */
1179 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
1180 {
1181 	struct mei_device *dev;
1182 	struct mei_msg_data *buf;
1183 	struct mei_msg_hdr mei_hdr;
1184 	int rets;
1185 
1186 
1187 	if (WARN_ON(!cl || !cl->dev))
1188 		return -ENODEV;
1189 
1190 	if (WARN_ON(!cb))
1191 		return -EINVAL;
1192 
1193 	dev = cl->dev;
1194 
1195 
1196 	buf = &cb->buf;
1197 
1198 	cl_dbg(dev, cl, "size=%d\n", buf->size);
1199 
1200 	rets = pm_runtime_get(dev->dev);
1201 	if (rets < 0 && rets != -EINPROGRESS) {
1202 		pm_runtime_put_noidle(dev->dev);
1203 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1204 		return rets;
1205 	}
1206 
1207 	cb->buf_idx = 0;
1208 	cl->writing_state = MEI_IDLE;
1209 
1210 	mei_hdr.host_addr = cl->host_client_id;
1211 	mei_hdr.me_addr = cl->me_client_id;
1212 	mei_hdr.reserved = 0;
1213 	mei_hdr.msg_complete = 0;
1214 	mei_hdr.internal = cb->internal;
1215 
1216 	rets = mei_cl_flow_ctrl_creds(cl);
1217 	if (rets < 0)
1218 		goto err;
1219 
1220 	if (rets == 0) {
1221 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1222 		rets = buf->size;
1223 		goto out;
1224 	}
1225 	if (!mei_hbuf_acquire(dev)) {
1226 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1227 		rets = buf->size;
1228 		goto out;
1229 	}
1230 
1231 	/* Check for a maximum length */
1232 	if (buf->size > mei_hbuf_max_len(dev)) {
1233 		mei_hdr.length = mei_hbuf_max_len(dev);
1234 		mei_hdr.msg_complete = 0;
1235 	} else {
1236 		mei_hdr.length = buf->size;
1237 		mei_hdr.msg_complete = 1;
1238 	}
1239 
1240 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1241 	if (rets)
1242 		goto err;
1243 
1244 	cl->writing_state = MEI_WRITING;
1245 	cb->buf_idx = mei_hdr.length;
1246 	cb->completed = mei_hdr.msg_complete == 1;
1247 
1248 out:
1249 	if (mei_hdr.msg_complete) {
1250 		rets = mei_cl_flow_ctrl_reduce(cl);
1251 		if (rets < 0)
1252 			goto err;
1253 
1254 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
1255 	} else {
1256 		list_add_tail(&cb->list, &dev->write_list.list);
1257 	}
1258 
1259 
1260 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1261 
1262 		mutex_unlock(&dev->device_lock);
1263 		rets = wait_event_interruptible(cl->tx_wait,
1264 				cl->writing_state == MEI_WRITE_COMPLETE);
1265 		mutex_lock(&dev->device_lock);
1266 		/* wait_event_interruptible returns -ERESTARTSYS */
1267 		if (rets) {
1268 			if (signal_pending(current))
1269 				rets = -EINTR;
1270 			goto err;
1271 		}
1272 	}
1273 
1274 	rets = buf->size;
1275 err:
1276 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1277 	pm_runtime_mark_last_busy(dev->dev);
1278 	pm_runtime_put_autosuspend(dev->dev);
1279 
1280 	return rets;
1281 }
1282 
1283 
1284 /**
1285  * mei_cl_complete - processes completed operation for a client
1286  *
1287  * @cl: private data of the file object.
1288  * @cb: callback block.
1289  */
1290 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1291 {
1292 	if (cb->fop_type == MEI_FOP_WRITE) {
1293 		mei_io_cb_free(cb);
1294 		cb = NULL;
1295 		cl->writing_state = MEI_WRITE_COMPLETE;
1296 		if (waitqueue_active(&cl->tx_wait))
1297 			wake_up_interruptible(&cl->tx_wait);
1298 
1299 	} else if (cb->fop_type == MEI_FOP_READ) {
1300 		list_add_tail(&cb->list, &cl->rd_completed);
1301 		if (waitqueue_active(&cl->rx_wait))
1302 			wake_up_interruptible_all(&cl->rx_wait);
1303 		else
1304 			mei_cl_bus_rx_event(cl);
1305 
1306 	}
1307 }
1308 
1309 
1310 /**
1311  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1312  *
1313  * @dev: mei device
1314  */
1315 
1316 void mei_cl_all_disconnect(struct mei_device *dev)
1317 {
1318 	struct mei_cl *cl;
1319 
1320 	list_for_each_entry(cl, &dev->file_list, link) {
1321 		cl->state = MEI_FILE_DISCONNECTED;
1322 		cl->mei_flow_ctrl_creds = 0;
1323 		cl->timer_count = 0;
1324 	}
1325 }
1326 
1327 
1328 /**
1329  * mei_cl_all_wakeup  - wake up all readers and writers they can be interrupted
1330  *
1331  * @dev: mei device
1332  */
1333 void mei_cl_all_wakeup(struct mei_device *dev)
1334 {
1335 	struct mei_cl *cl;
1336 
1337 	list_for_each_entry(cl, &dev->file_list, link) {
1338 		if (waitqueue_active(&cl->rx_wait)) {
1339 			cl_dbg(dev, cl, "Waking up reading client!\n");
1340 			wake_up_interruptible(&cl->rx_wait);
1341 		}
1342 		if (waitqueue_active(&cl->tx_wait)) {
1343 			cl_dbg(dev, cl, "Waking up writing client!\n");
1344 			wake_up_interruptible(&cl->tx_wait);
1345 		}
1346 	}
1347 }
1348 
1349 /**
1350  * mei_cl_all_write_clear - clear all pending writes
1351  *
1352  * @dev: mei device
1353  */
1354 void mei_cl_all_write_clear(struct mei_device *dev)
1355 {
1356 	mei_io_list_free(&dev->write_list, NULL);
1357 	mei_io_list_free(&dev->write_waiting_list, NULL);
1358 }
1359 
1360 
1361