xref: /linux/drivers/misc/mei/client.c (revision 69f1804a)
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 from 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_init(&me_cl->list);
100 	mei_me_cl_put(me_cl);
101 }
102 
103 /**
104  * mei_me_cl_del - delete me client from the list and decrease
105  *     reference counter
106  *
107  * @dev: mei device
108  * @me_cl: me client
109  */
110 void mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
111 {
112 	down_write(&dev->me_clients_rwsem);
113 	__mei_me_cl_del(dev, me_cl);
114 	up_write(&dev->me_clients_rwsem);
115 }
116 
117 /**
118  * mei_me_cl_add - add me client to the list
119  *
120  * @dev: mei device
121  * @me_cl: me client
122  */
123 void mei_me_cl_add(struct mei_device *dev, struct mei_me_client *me_cl)
124 {
125 	down_write(&dev->me_clients_rwsem);
126 	list_add(&me_cl->list, &dev->me_clients);
127 	up_write(&dev->me_clients_rwsem);
128 }
129 
130 /**
131  * __mei_me_cl_by_uuid - locate me client by uuid
132  *	increases ref count
133  *
134  * @dev: mei device
135  * @uuid: me client uuid
136  *
137  * Return: me client or NULL if not found
138  *
139  * Locking: dev->me_clients_rwsem
140  */
141 static struct mei_me_client *__mei_me_cl_by_uuid(struct mei_device *dev,
142 					const uuid_le *uuid)
143 {
144 	struct mei_me_client *me_cl;
145 	const uuid_le *pn;
146 
147 	WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
148 
149 	list_for_each_entry(me_cl, &dev->me_clients, list) {
150 		pn = &me_cl->props.protocol_name;
151 		if (uuid_le_cmp(*uuid, *pn) == 0)
152 			return mei_me_cl_get(me_cl);
153 	}
154 
155 	return NULL;
156 }
157 
158 /**
159  * mei_me_cl_by_uuid - locate me client by uuid
160  *	increases ref count
161  *
162  * @dev: mei device
163  * @uuid: me client uuid
164  *
165  * Return: me client or NULL if not found
166  *
167  * Locking: dev->me_clients_rwsem
168  */
169 struct mei_me_client *mei_me_cl_by_uuid(struct mei_device *dev,
170 					const uuid_le *uuid)
171 {
172 	struct mei_me_client *me_cl;
173 
174 	down_read(&dev->me_clients_rwsem);
175 	me_cl = __mei_me_cl_by_uuid(dev, uuid);
176 	up_read(&dev->me_clients_rwsem);
177 
178 	return me_cl;
179 }
180 
181 /**
182  * mei_me_cl_by_id - locate me client by client id
183  *	increases ref count
184  *
185  * @dev: the device structure
186  * @client_id: me client id
187  *
188  * Return: me client or NULL if not found
189  *
190  * Locking: dev->me_clients_rwsem
191  */
192 struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
193 {
194 
195 	struct mei_me_client *__me_cl, *me_cl = NULL;
196 
197 	down_read(&dev->me_clients_rwsem);
198 	list_for_each_entry(__me_cl, &dev->me_clients, list) {
199 		if (__me_cl->client_id == client_id) {
200 			me_cl = mei_me_cl_get(__me_cl);
201 			break;
202 		}
203 	}
204 	up_read(&dev->me_clients_rwsem);
205 
206 	return me_cl;
207 }
208 
209 /**
210  * __mei_me_cl_by_uuid_id - locate me client by client id and uuid
211  *	increases ref count
212  *
213  * @dev: the device structure
214  * @uuid: me client uuid
215  * @client_id: me client id
216  *
217  * Return: me client or null if not found
218  *
219  * Locking: dev->me_clients_rwsem
220  */
221 static struct mei_me_client *__mei_me_cl_by_uuid_id(struct mei_device *dev,
222 					   const uuid_le *uuid, u8 client_id)
223 {
224 	struct mei_me_client *me_cl;
225 	const uuid_le *pn;
226 
227 	WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
228 
229 	list_for_each_entry(me_cl, &dev->me_clients, list) {
230 		pn = &me_cl->props.protocol_name;
231 		if (uuid_le_cmp(*uuid, *pn) == 0 &&
232 		    me_cl->client_id == client_id)
233 			return mei_me_cl_get(me_cl);
234 	}
235 
236 	return NULL;
237 }
238 
239 
240 /**
241  * mei_me_cl_by_uuid_id - locate me client by client id and uuid
242  *	increases ref count
243  *
244  * @dev: the device structure
245  * @uuid: me client uuid
246  * @client_id: me client id
247  *
248  * Return: me client or null if not found
249  */
250 struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev,
251 					   const uuid_le *uuid, u8 client_id)
252 {
253 	struct mei_me_client *me_cl;
254 
255 	down_read(&dev->me_clients_rwsem);
256 	me_cl = __mei_me_cl_by_uuid_id(dev, uuid, client_id);
257 	up_read(&dev->me_clients_rwsem);
258 
259 	return me_cl;
260 }
261 
262 /**
263  * mei_me_cl_rm_by_uuid - remove all me clients matching uuid
264  *
265  * @dev: the device structure
266  * @uuid: me client uuid
267  *
268  * Locking: called under "dev->device_lock" lock
269  */
270 void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)
271 {
272 	struct mei_me_client *me_cl;
273 
274 	dev_dbg(dev->dev, "remove %pUl\n", uuid);
275 
276 	down_write(&dev->me_clients_rwsem);
277 	me_cl = __mei_me_cl_by_uuid(dev, uuid);
278 	__mei_me_cl_del(dev, me_cl);
279 	up_write(&dev->me_clients_rwsem);
280 }
281 
282 /**
283  * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id
284  *
285  * @dev: the device structure
286  * @uuid: me client uuid
287  * @id: me client id
288  *
289  * Locking: called under "dev->device_lock" lock
290  */
291 void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)
292 {
293 	struct mei_me_client *me_cl;
294 
295 	dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);
296 
297 	down_write(&dev->me_clients_rwsem);
298 	me_cl = __mei_me_cl_by_uuid_id(dev, uuid, id);
299 	__mei_me_cl_del(dev, me_cl);
300 	up_write(&dev->me_clients_rwsem);
301 }
302 
303 /**
304  * mei_me_cl_rm_all - remove all me clients
305  *
306  * @dev: the device structure
307  *
308  * Locking: called under "dev->device_lock" lock
309  */
310 void mei_me_cl_rm_all(struct mei_device *dev)
311 {
312 	struct mei_me_client *me_cl, *next;
313 
314 	down_write(&dev->me_clients_rwsem);
315 	list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
316 		__mei_me_cl_del(dev, me_cl);
317 	up_write(&dev->me_clients_rwsem);
318 }
319 
320 /**
321  * mei_cl_cmp_id - tells if the clients are the same
322  *
323  * @cl1: host client 1
324  * @cl2: host client 2
325  *
326  * Return: true  - if the clients has same host and me ids
327  *         false - otherwise
328  */
329 static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
330 				const struct mei_cl *cl2)
331 {
332 	return cl1 && cl2 &&
333 		(cl1->host_client_id == cl2->host_client_id) &&
334 		(mei_cl_me_id(cl1) == mei_cl_me_id(cl2));
335 }
336 
337 /**
338  * mei_io_cb_free - free mei_cb_private related memory
339  *
340  * @cb: mei callback struct
341  */
342 void mei_io_cb_free(struct mei_cl_cb *cb)
343 {
344 	if (cb == NULL)
345 		return;
346 
347 	list_del(&cb->list);
348 	kfree(cb->buf.data);
349 	kfree(cb);
350 }
351 
352 /**
353  * mei_io_cb_init - allocate and initialize io callback
354  *
355  * @cl: mei client
356  * @type: operation type
357  * @fp: pointer to file structure
358  *
359  * Return: mei_cl_cb pointer or NULL;
360  */
361 struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, enum mei_cb_file_ops type,
362 				 const struct file *fp)
363 {
364 	struct mei_cl_cb *cb;
365 
366 	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
367 	if (!cb)
368 		return NULL;
369 
370 	INIT_LIST_HEAD(&cb->list);
371 	cb->fp = fp;
372 	cb->cl = cl;
373 	cb->buf_idx = 0;
374 	cb->fop_type = type;
375 	return cb;
376 }
377 
378 /**
379  * __mei_io_list_flush - removes and frees cbs belonging to cl.
380  *
381  * @list:  an instance of our list structure
382  * @cl:    host client, can be NULL for flushing the whole list
383  * @free:  whether to free the cbs
384  */
385 static void __mei_io_list_flush(struct mei_cl_cb *list,
386 				struct mei_cl *cl, bool free)
387 {
388 	struct mei_cl_cb *cb, *next;
389 
390 	/* enable removing everything if no cl is specified */
391 	list_for_each_entry_safe(cb, next, &list->list, list) {
392 		if (!cl || mei_cl_cmp_id(cl, cb->cl)) {
393 			list_del_init(&cb->list);
394 			if (free)
395 				mei_io_cb_free(cb);
396 		}
397 	}
398 }
399 
400 /**
401  * mei_io_list_flush - removes list entry belonging to cl.
402  *
403  * @list:  An instance of our list structure
404  * @cl: host client
405  */
406 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
407 {
408 	__mei_io_list_flush(list, cl, false);
409 }
410 
411 /**
412  * mei_io_list_free - removes cb belonging to cl and free them
413  *
414  * @list:  An instance of our list structure
415  * @cl: host client
416  */
417 static inline void mei_io_list_free(struct mei_cl_cb *list, struct mei_cl *cl)
418 {
419 	__mei_io_list_flush(list, cl, true);
420 }
421 
422 /**
423  * mei_io_cb_alloc_buf - allocate callback buffer
424  *
425  * @cb: io callback structure
426  * @length: size of the buffer
427  *
428  * Return: 0 on success
429  *         -EINVAL if cb is NULL
430  *         -ENOMEM if allocation failed
431  */
432 int mei_io_cb_alloc_buf(struct mei_cl_cb *cb, size_t length)
433 {
434 	if (!cb)
435 		return -EINVAL;
436 
437 	if (length == 0)
438 		return 0;
439 
440 	cb->buf.data = kmalloc(length, GFP_KERNEL);
441 	if (!cb->buf.data)
442 		return -ENOMEM;
443 	cb->buf.size = length;
444 	return 0;
445 }
446 
447 /**
448  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
449  *
450  * @cl: host client
451  * @length: size of the buffer
452  * @type: operation type
453  * @fp: associated file pointer (might be NULL)
454  *
455  * Return: cb on success and NULL on failure
456  */
457 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
458 				  enum mei_cb_file_ops type,
459 				  const struct file *fp)
460 {
461 	struct mei_cl_cb *cb;
462 
463 	cb = mei_io_cb_init(cl, type, fp);
464 	if (!cb)
465 		return NULL;
466 
467 	if (mei_io_cb_alloc_buf(cb, length)) {
468 		mei_io_cb_free(cb);
469 		return NULL;
470 	}
471 
472 	return cb;
473 }
474 
475 /**
476  * mei_cl_read_cb - find this cl's callback in the read list
477  *     for a specific file
478  *
479  * @cl: host client
480  * @fp: file pointer (matching cb file object), may be NULL
481  *
482  * Return: cb on success, NULL if cb is not found
483  */
484 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
485 {
486 	struct mei_cl_cb *cb;
487 
488 	list_for_each_entry(cb, &cl->rd_completed, list)
489 		if (!fp || fp == cb->fp)
490 			return cb;
491 
492 	return NULL;
493 }
494 
495 /**
496  * mei_cl_read_cb_flush - free client's read pending and completed cbs
497  *   for a specific file
498  *
499  * @cl: host client
500  * @fp: file pointer (matching cb file object), may be NULL
501  */
502 void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp)
503 {
504 	struct mei_cl_cb *cb, *next;
505 
506 	list_for_each_entry_safe(cb, next, &cl->rd_completed, list)
507 		if (!fp || fp == cb->fp)
508 			mei_io_cb_free(cb);
509 
510 
511 	list_for_each_entry_safe(cb, next, &cl->rd_pending, list)
512 		if (!fp || fp == cb->fp)
513 			mei_io_cb_free(cb);
514 }
515 
516 /**
517  * mei_cl_flush_queues - flushes queue lists belonging to cl.
518  *
519  * @cl: host client
520  * @fp: file pointer (matching cb file object), may be NULL
521  *
522  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
523  */
524 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
525 {
526 	struct mei_device *dev;
527 
528 	if (WARN_ON(!cl || !cl->dev))
529 		return -EINVAL;
530 
531 	dev = cl->dev;
532 
533 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
534 	mei_io_list_free(&cl->dev->write_list, cl);
535 	mei_io_list_free(&cl->dev->write_waiting_list, cl);
536 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
537 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
538 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
539 
540 	mei_cl_read_cb_flush(cl, fp);
541 
542 	return 0;
543 }
544 
545 
546 /**
547  * mei_cl_init - initializes cl.
548  *
549  * @cl: host client to be initialized
550  * @dev: mei device
551  */
552 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
553 {
554 	memset(cl, 0, sizeof(struct mei_cl));
555 	init_waitqueue_head(&cl->wait);
556 	init_waitqueue_head(&cl->rx_wait);
557 	init_waitqueue_head(&cl->tx_wait);
558 	init_waitqueue_head(&cl->ev_wait);
559 	INIT_LIST_HEAD(&cl->rd_completed);
560 	INIT_LIST_HEAD(&cl->rd_pending);
561 	INIT_LIST_HEAD(&cl->link);
562 	cl->writing_state = MEI_IDLE;
563 	cl->state = MEI_FILE_INITIALIZING;
564 	cl->dev = dev;
565 }
566 
567 /**
568  * mei_cl_allocate - allocates cl  structure and sets it up.
569  *
570  * @dev: mei device
571  * Return:  The allocated file or NULL on failure
572  */
573 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
574 {
575 	struct mei_cl *cl;
576 
577 	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
578 	if (!cl)
579 		return NULL;
580 
581 	mei_cl_init(cl, dev);
582 
583 	return cl;
584 }
585 
586 /**
587  * mei_cl_link - allocate host id in the host map
588  *
589  * @cl: host client
590  *
591  * Return: 0 on success
592  *	-EINVAL on incorrect values
593  *	-EMFILE if open count exceeded.
594  */
595 int mei_cl_link(struct mei_cl *cl)
596 {
597 	struct mei_device *dev;
598 	long open_handle_count;
599 	int id;
600 
601 	if (WARN_ON(!cl || !cl->dev))
602 		return -EINVAL;
603 
604 	dev = cl->dev;
605 
606 	id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
607 	if (id >= MEI_CLIENTS_MAX) {
608 		dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
609 		return -EMFILE;
610 	}
611 
612 	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
613 	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
614 		dev_err(dev->dev, "open_handle_count exceeded %d",
615 			MEI_MAX_OPEN_HANDLE_COUNT);
616 		return -EMFILE;
617 	}
618 
619 	dev->open_handle_count++;
620 
621 	cl->host_client_id = id;
622 	list_add_tail(&cl->link, &dev->file_list);
623 
624 	set_bit(id, dev->host_clients_map);
625 
626 	cl->state = MEI_FILE_INITIALIZING;
627 
628 	cl_dbg(dev, cl, "link cl\n");
629 	return 0;
630 }
631 
632 /**
633  * mei_cl_unlink - remove host client from the list
634  *
635  * @cl: host client
636  *
637  * Return: always 0
638  */
639 int mei_cl_unlink(struct mei_cl *cl)
640 {
641 	struct mei_device *dev;
642 
643 	/* don't shout on error exit path */
644 	if (!cl)
645 		return 0;
646 
647 	/* amthif might not be initialized */
648 	if (!cl->dev)
649 		return 0;
650 
651 	dev = cl->dev;
652 
653 	cl_dbg(dev, cl, "unlink client");
654 
655 	if (dev->open_handle_count > 0)
656 		dev->open_handle_count--;
657 
658 	/* never clear the 0 bit */
659 	if (cl->host_client_id)
660 		clear_bit(cl->host_client_id, dev->host_clients_map);
661 
662 	list_del_init(&cl->link);
663 
664 	cl->state = MEI_FILE_INITIALIZING;
665 
666 	return 0;
667 }
668 
669 void mei_host_client_init(struct mei_device *dev)
670 {
671 	dev->dev_state = MEI_DEV_ENABLED;
672 	dev->reset_count = 0;
673 
674 	schedule_work(&dev->bus_rescan_work);
675 
676 	pm_runtime_mark_last_busy(dev->dev);
677 	dev_dbg(dev->dev, "rpm: autosuspend\n");
678 	pm_runtime_autosuspend(dev->dev);
679 }
680 
681 /**
682  * mei_hbuf_acquire - try to acquire host buffer
683  *
684  * @dev: the device structure
685  * Return: true if host buffer was acquired
686  */
687 bool mei_hbuf_acquire(struct mei_device *dev)
688 {
689 	if (mei_pg_state(dev) == MEI_PG_ON ||
690 	    mei_pg_in_transition(dev)) {
691 		dev_dbg(dev->dev, "device is in pg\n");
692 		return false;
693 	}
694 
695 	if (!dev->hbuf_is_ready) {
696 		dev_dbg(dev->dev, "hbuf is not ready\n");
697 		return false;
698 	}
699 
700 	dev->hbuf_is_ready = false;
701 
702 	return true;
703 }
704 
705 /**
706  * mei_cl_wake_all - wake up readers, writers and event waiters so
707  *                 they can be interrupted
708  *
709  * @cl: host client
710  */
711 static void mei_cl_wake_all(struct mei_cl *cl)
712 {
713 	struct mei_device *dev = cl->dev;
714 
715 	/* synchronized under device mutex */
716 	if (waitqueue_active(&cl->rx_wait)) {
717 		cl_dbg(dev, cl, "Waking up reading client!\n");
718 		wake_up_interruptible(&cl->rx_wait);
719 	}
720 	/* synchronized under device mutex */
721 	if (waitqueue_active(&cl->tx_wait)) {
722 		cl_dbg(dev, cl, "Waking up writing client!\n");
723 		wake_up_interruptible(&cl->tx_wait);
724 	}
725 	/* synchronized under device mutex */
726 	if (waitqueue_active(&cl->ev_wait)) {
727 		cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
728 		wake_up_interruptible(&cl->ev_wait);
729 	}
730 	/* synchronized under device mutex */
731 	if (waitqueue_active(&cl->wait)) {
732 		cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
733 		wake_up(&cl->wait);
734 	}
735 }
736 
737 /**
738  * mei_cl_set_disconnected - set disconnected state and clear
739  *   associated states and resources
740  *
741  * @cl: host client
742  */
743 void mei_cl_set_disconnected(struct mei_cl *cl)
744 {
745 	struct mei_device *dev = cl->dev;
746 
747 	if (cl->state == MEI_FILE_DISCONNECTED ||
748 	    cl->state == MEI_FILE_INITIALIZING)
749 		return;
750 
751 	cl->state = MEI_FILE_DISCONNECTED;
752 	mei_io_list_free(&dev->write_list, cl);
753 	mei_io_list_free(&dev->write_waiting_list, cl);
754 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
755 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
756 	mei_cl_wake_all(cl);
757 	cl->mei_flow_ctrl_creds = 0;
758 	cl->timer_count = 0;
759 
760 	if (!cl->me_cl)
761 		return;
762 
763 	if (!WARN_ON(cl->me_cl->connect_count == 0))
764 		cl->me_cl->connect_count--;
765 
766 	if (cl->me_cl->connect_count == 0)
767 		cl->me_cl->mei_flow_ctrl_creds = 0;
768 
769 	mei_me_cl_put(cl->me_cl);
770 	cl->me_cl = NULL;
771 }
772 
773 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
774 {
775 	if (!mei_me_cl_get(me_cl))
776 		return -ENOENT;
777 
778 	/* only one connection is allowed for fixed address clients */
779 	if (me_cl->props.fixed_address) {
780 		if (me_cl->connect_count) {
781 			mei_me_cl_put(me_cl);
782 			return -EBUSY;
783 		}
784 	}
785 
786 	cl->me_cl = me_cl;
787 	cl->state = MEI_FILE_CONNECTING;
788 	cl->me_cl->connect_count++;
789 
790 	return 0;
791 }
792 
793 /*
794  * mei_cl_send_disconnect - send disconnect request
795  *
796  * @cl: host client
797  * @cb: callback block
798  *
799  * Return: 0, OK; otherwise, error.
800  */
801 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
802 {
803 	struct mei_device *dev;
804 	int ret;
805 
806 	dev = cl->dev;
807 
808 	ret = mei_hbm_cl_disconnect_req(dev, cl);
809 	cl->status = ret;
810 	if (ret) {
811 		cl->state = MEI_FILE_DISCONNECT_REPLY;
812 		return ret;
813 	}
814 
815 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
816 	cl->timer_count = MEI_CONNECT_TIMEOUT;
817 
818 	return 0;
819 }
820 
821 /**
822  * mei_cl_irq_disconnect - processes close related operation from
823  *	interrupt thread context - send disconnect request
824  *
825  * @cl: client
826  * @cb: callback block.
827  * @cmpl_list: complete list.
828  *
829  * Return: 0, OK; otherwise, error.
830  */
831 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
832 			    struct mei_cl_cb *cmpl_list)
833 {
834 	struct mei_device *dev = cl->dev;
835 	u32 msg_slots;
836 	int slots;
837 	int ret;
838 
839 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
840 	slots = mei_hbuf_empty_slots(dev);
841 
842 	if (slots < msg_slots)
843 		return -EMSGSIZE;
844 
845 	ret = mei_cl_send_disconnect(cl, cb);
846 	if (ret)
847 		list_move_tail(&cb->list, &cmpl_list->list);
848 
849 	return ret;
850 }
851 
852 /**
853  * __mei_cl_disconnect - disconnect host client from the me one
854  *     internal function runtime pm has to be already acquired
855  *
856  * @cl: host client
857  *
858  * Return: 0 on success, <0 on failure.
859  */
860 static int __mei_cl_disconnect(struct mei_cl *cl)
861 {
862 	struct mei_device *dev;
863 	struct mei_cl_cb *cb;
864 	int rets;
865 
866 	dev = cl->dev;
867 
868 	cl->state = MEI_FILE_DISCONNECTING;
869 
870 	cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT, NULL);
871 	rets = cb ? 0 : -ENOMEM;
872 	if (rets)
873 		goto out;
874 
875 	cl_dbg(dev, cl, "add disconnect cb to control write list\n");
876 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
877 
878 	if (mei_hbuf_acquire(dev)) {
879 		rets = mei_cl_send_disconnect(cl, cb);
880 		if (rets) {
881 			cl_err(dev, cl, "failed to disconnect.\n");
882 			goto out;
883 		}
884 	}
885 
886 	mutex_unlock(&dev->device_lock);
887 	wait_event_timeout(cl->wait,
888 			   cl->state == MEI_FILE_DISCONNECT_REPLY ||
889 			   cl->state == MEI_FILE_DISCONNECTED,
890 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
891 	mutex_lock(&dev->device_lock);
892 
893 	rets = cl->status;
894 	if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
895 	    cl->state != MEI_FILE_DISCONNECTED) {
896 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
897 		rets = -ETIME;
898 	}
899 
900 out:
901 	/* we disconnect also on error */
902 	mei_cl_set_disconnected(cl);
903 	if (!rets)
904 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
905 
906 	mei_io_cb_free(cb);
907 	return rets;
908 }
909 
910 /**
911  * mei_cl_disconnect - disconnect host client from the me one
912  *
913  * @cl: host client
914  *
915  * Locking: called under "dev->device_lock" lock
916  *
917  * Return: 0 on success, <0 on failure.
918  */
919 int mei_cl_disconnect(struct mei_cl *cl)
920 {
921 	struct mei_device *dev;
922 	int rets;
923 
924 	if (WARN_ON(!cl || !cl->dev))
925 		return -ENODEV;
926 
927 	dev = cl->dev;
928 
929 	cl_dbg(dev, cl, "disconnecting");
930 
931 	if (!mei_cl_is_connected(cl))
932 		return 0;
933 
934 	if (mei_cl_is_fixed_address(cl)) {
935 		mei_cl_set_disconnected(cl);
936 		return 0;
937 	}
938 
939 	rets = pm_runtime_get(dev->dev);
940 	if (rets < 0 && rets != -EINPROGRESS) {
941 		pm_runtime_put_noidle(dev->dev);
942 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
943 		return rets;
944 	}
945 
946 	rets = __mei_cl_disconnect(cl);
947 
948 	cl_dbg(dev, cl, "rpm: autosuspend\n");
949 	pm_runtime_mark_last_busy(dev->dev);
950 	pm_runtime_put_autosuspend(dev->dev);
951 
952 	return rets;
953 }
954 
955 
956 /**
957  * mei_cl_is_other_connecting - checks if other
958  *    client with the same me client id is connecting
959  *
960  * @cl: private data of the file object
961  *
962  * Return: true if other client is connected, false - otherwise.
963  */
964 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
965 {
966 	struct mei_device *dev;
967 	struct mei_cl_cb *cb;
968 
969 	dev = cl->dev;
970 
971 	list_for_each_entry(cb, &dev->ctrl_rd_list.list, list) {
972 		if (cb->fop_type == MEI_FOP_CONNECT &&
973 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
974 			return true;
975 	}
976 
977 	return false;
978 }
979 
980 /**
981  * mei_cl_send_connect - send connect request
982  *
983  * @cl: host client
984  * @cb: callback block
985  *
986  * Return: 0, OK; otherwise, error.
987  */
988 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
989 {
990 	struct mei_device *dev;
991 	int ret;
992 
993 	dev = cl->dev;
994 
995 	ret = mei_hbm_cl_connect_req(dev, cl);
996 	cl->status = ret;
997 	if (ret) {
998 		cl->state = MEI_FILE_DISCONNECT_REPLY;
999 		return ret;
1000 	}
1001 
1002 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1003 	cl->timer_count = MEI_CONNECT_TIMEOUT;
1004 	return 0;
1005 }
1006 
1007 /**
1008  * mei_cl_irq_connect - send connect request in irq_thread context
1009  *
1010  * @cl: host client
1011  * @cb: callback block
1012  * @cmpl_list: complete list
1013  *
1014  * Return: 0, OK; otherwise, error.
1015  */
1016 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1017 			      struct mei_cl_cb *cmpl_list)
1018 {
1019 	struct mei_device *dev = cl->dev;
1020 	u32 msg_slots;
1021 	int slots;
1022 	int rets;
1023 
1024 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1025 	slots = mei_hbuf_empty_slots(dev);
1026 
1027 	if (mei_cl_is_other_connecting(cl))
1028 		return 0;
1029 
1030 	if (slots < msg_slots)
1031 		return -EMSGSIZE;
1032 
1033 	rets = mei_cl_send_connect(cl, cb);
1034 	if (rets)
1035 		list_move_tail(&cb->list, &cmpl_list->list);
1036 
1037 	return rets;
1038 }
1039 
1040 /**
1041  * mei_cl_connect - connect host client to the me one
1042  *
1043  * @cl: host client
1044  * @me_cl: me client
1045  * @file: pointer to file structure
1046  *
1047  * Locking: called under "dev->device_lock" lock
1048  *
1049  * Return: 0 on success, <0 on failure.
1050  */
1051 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1052 		  const struct file *file)
1053 {
1054 	struct mei_device *dev;
1055 	struct mei_cl_cb *cb;
1056 	int rets;
1057 
1058 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1059 		return -ENODEV;
1060 
1061 	dev = cl->dev;
1062 
1063 	rets = mei_cl_set_connecting(cl, me_cl);
1064 	if (rets)
1065 		return rets;
1066 
1067 	if (mei_cl_is_fixed_address(cl)) {
1068 		cl->state = MEI_FILE_CONNECTED;
1069 		return 0;
1070 	}
1071 
1072 	rets = pm_runtime_get(dev->dev);
1073 	if (rets < 0 && rets != -EINPROGRESS) {
1074 		pm_runtime_put_noidle(dev->dev);
1075 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1076 		goto nortpm;
1077 	}
1078 
1079 	cb = mei_io_cb_init(cl, MEI_FOP_CONNECT, file);
1080 	rets = cb ? 0 : -ENOMEM;
1081 	if (rets)
1082 		goto out;
1083 
1084 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1085 
1086 	/* run hbuf acquire last so we don't have to undo */
1087 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1088 		rets = mei_cl_send_connect(cl, cb);
1089 		if (rets)
1090 			goto out;
1091 	}
1092 
1093 	mutex_unlock(&dev->device_lock);
1094 	wait_event_timeout(cl->wait,
1095 			(cl->state == MEI_FILE_CONNECTED ||
1096 			 cl->state == MEI_FILE_DISCONNECTED ||
1097 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1098 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1099 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1100 	mutex_lock(&dev->device_lock);
1101 
1102 	if (!mei_cl_is_connected(cl)) {
1103 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1104 			mei_io_list_flush(&dev->ctrl_rd_list, cl);
1105 			mei_io_list_flush(&dev->ctrl_wr_list, cl);
1106 			 /* ignore disconnect return valuue;
1107 			  * in case of failure reset will be invoked
1108 			  */
1109 			__mei_cl_disconnect(cl);
1110 			rets = -EFAULT;
1111 			goto out;
1112 		}
1113 
1114 		/* timeout or something went really wrong */
1115 		if (!cl->status)
1116 			cl->status = -EFAULT;
1117 	}
1118 
1119 	rets = cl->status;
1120 out:
1121 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1122 	pm_runtime_mark_last_busy(dev->dev);
1123 	pm_runtime_put_autosuspend(dev->dev);
1124 
1125 	mei_io_cb_free(cb);
1126 
1127 nortpm:
1128 	if (!mei_cl_is_connected(cl))
1129 		mei_cl_set_disconnected(cl);
1130 
1131 	return rets;
1132 }
1133 
1134 /**
1135  * mei_cl_alloc_linked - allocate and link host client
1136  *
1137  * @dev: the device structure
1138  *
1139  * Return: cl on success ERR_PTR on failure
1140  */
1141 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1142 {
1143 	struct mei_cl *cl;
1144 	int ret;
1145 
1146 	cl = mei_cl_allocate(dev);
1147 	if (!cl) {
1148 		ret = -ENOMEM;
1149 		goto err;
1150 	}
1151 
1152 	ret = mei_cl_link(cl);
1153 	if (ret)
1154 		goto err;
1155 
1156 	return cl;
1157 err:
1158 	kfree(cl);
1159 	return ERR_PTR(ret);
1160 }
1161 
1162 
1163 
1164 /**
1165  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
1166  *
1167  * @cl: host client
1168  * @fp: the file pointer associated with the pointer
1169  *
1170  * Return: 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
1171  */
1172 static int mei_cl_flow_ctrl_creds(struct mei_cl *cl, const struct file *fp)
1173 {
1174 	int rets;
1175 
1176 	if (WARN_ON(!cl || !cl->me_cl))
1177 		return -EINVAL;
1178 
1179 	if (cl->mei_flow_ctrl_creds > 0)
1180 		return 1;
1181 
1182 	if (mei_cl_is_fixed_address(cl)) {
1183 		rets = mei_cl_read_start(cl, mei_cl_mtu(cl), fp);
1184 		if (rets && rets != -EBUSY)
1185 			return rets;
1186 		return 1;
1187 	}
1188 
1189 	if (mei_cl_is_single_recv_buf(cl)) {
1190 		if (cl->me_cl->mei_flow_ctrl_creds > 0)
1191 			return 1;
1192 	}
1193 	return 0;
1194 }
1195 
1196 /**
1197  * mei_cl_flow_ctrl_reduce - reduces flow_control.
1198  *
1199  * @cl: private data of the file object
1200  *
1201  * Return:
1202  *	0 on success
1203  *	-EINVAL when ctrl credits are <= 0
1204  */
1205 static int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
1206 {
1207 	if (WARN_ON(!cl || !cl->me_cl))
1208 		return -EINVAL;
1209 
1210 	if (mei_cl_is_fixed_address(cl))
1211 		return 0;
1212 
1213 	if (mei_cl_is_single_recv_buf(cl)) {
1214 		if (WARN_ON(cl->me_cl->mei_flow_ctrl_creds <= 0))
1215 			return -EINVAL;
1216 		cl->me_cl->mei_flow_ctrl_creds--;
1217 	} else {
1218 		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
1219 			return -EINVAL;
1220 		cl->mei_flow_ctrl_creds--;
1221 	}
1222 	return 0;
1223 }
1224 
1225 /**
1226  *  mei_cl_notify_fop2req - convert fop to proper request
1227  *
1228  * @fop: client notification start response command
1229  *
1230  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1231  */
1232 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1233 {
1234 	if (fop == MEI_FOP_NOTIFY_START)
1235 		return MEI_HBM_NOTIFICATION_START;
1236 	else
1237 		return MEI_HBM_NOTIFICATION_STOP;
1238 }
1239 
1240 /**
1241  *  mei_cl_notify_req2fop - convert notification request top file operation type
1242  *
1243  * @req: hbm notification request type
1244  *
1245  * Return:  MEI_FOP_NOTIFY_START/STOP
1246  */
1247 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1248 {
1249 	if (req == MEI_HBM_NOTIFICATION_START)
1250 		return MEI_FOP_NOTIFY_START;
1251 	else
1252 		return MEI_FOP_NOTIFY_STOP;
1253 }
1254 
1255 /**
1256  * mei_cl_irq_notify - send notification request in irq_thread context
1257  *
1258  * @cl: client
1259  * @cb: callback block.
1260  * @cmpl_list: complete list.
1261  *
1262  * Return: 0 on such and error otherwise.
1263  */
1264 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1265 		      struct mei_cl_cb *cmpl_list)
1266 {
1267 	struct mei_device *dev = cl->dev;
1268 	u32 msg_slots;
1269 	int slots;
1270 	int ret;
1271 	bool request;
1272 
1273 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1274 	slots = mei_hbuf_empty_slots(dev);
1275 
1276 	if (slots < msg_slots)
1277 		return -EMSGSIZE;
1278 
1279 	request = mei_cl_notify_fop2req(cb->fop_type);
1280 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1281 	if (ret) {
1282 		cl->status = ret;
1283 		list_move_tail(&cb->list, &cmpl_list->list);
1284 		return ret;
1285 	}
1286 
1287 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1288 	return 0;
1289 }
1290 
1291 /**
1292  * mei_cl_notify_request - send notification stop/start request
1293  *
1294  * @cl: host client
1295  * @file: associate request with file
1296  * @request: 1 for start or 0 for stop
1297  *
1298  * Locking: called under "dev->device_lock" lock
1299  *
1300  * Return: 0 on such and error otherwise.
1301  */
1302 int mei_cl_notify_request(struct mei_cl *cl,
1303 			  const struct file *file, u8 request)
1304 {
1305 	struct mei_device *dev;
1306 	struct mei_cl_cb *cb;
1307 	enum mei_cb_file_ops fop_type;
1308 	int rets;
1309 
1310 	if (WARN_ON(!cl || !cl->dev))
1311 		return -ENODEV;
1312 
1313 	dev = cl->dev;
1314 
1315 	if (!dev->hbm_f_ev_supported) {
1316 		cl_dbg(dev, cl, "notifications not supported\n");
1317 		return -EOPNOTSUPP;
1318 	}
1319 
1320 	rets = pm_runtime_get(dev->dev);
1321 	if (rets < 0 && rets != -EINPROGRESS) {
1322 		pm_runtime_put_noidle(dev->dev);
1323 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1324 		return rets;
1325 	}
1326 
1327 	fop_type = mei_cl_notify_req2fop(request);
1328 	cb = mei_io_cb_init(cl, fop_type, file);
1329 	if (!cb) {
1330 		rets = -ENOMEM;
1331 		goto out;
1332 	}
1333 
1334 	if (mei_hbuf_acquire(dev)) {
1335 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1336 			rets = -ENODEV;
1337 			goto out;
1338 		}
1339 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
1340 	} else {
1341 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1342 	}
1343 
1344 	mutex_unlock(&dev->device_lock);
1345 	wait_event_timeout(cl->wait,
1346 			   cl->notify_en == request || !mei_cl_is_connected(cl),
1347 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1348 	mutex_lock(&dev->device_lock);
1349 
1350 	if (cl->notify_en != request && !cl->status)
1351 		cl->status = -EFAULT;
1352 
1353 	rets = cl->status;
1354 
1355 out:
1356 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1357 	pm_runtime_mark_last_busy(dev->dev);
1358 	pm_runtime_put_autosuspend(dev->dev);
1359 
1360 	mei_io_cb_free(cb);
1361 	return rets;
1362 }
1363 
1364 /**
1365  * mei_cl_notify - raise notification
1366  *
1367  * @cl: host client
1368  *
1369  * Locking: called under "dev->device_lock" lock
1370  */
1371 void mei_cl_notify(struct mei_cl *cl)
1372 {
1373 	struct mei_device *dev;
1374 
1375 	if (!cl || !cl->dev)
1376 		return;
1377 
1378 	dev = cl->dev;
1379 
1380 	if (!cl->notify_en)
1381 		return;
1382 
1383 	cl_dbg(dev, cl, "notify event");
1384 	cl->notify_ev = true;
1385 	if (!mei_cl_bus_notify_event(cl))
1386 		wake_up_interruptible(&cl->ev_wait);
1387 
1388 	if (cl->ev_async)
1389 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1390 
1391 }
1392 
1393 /**
1394  * mei_cl_notify_get - get or wait for notification event
1395  *
1396  * @cl: host client
1397  * @block: this request is blocking
1398  * @notify_ev: true if notification event was received
1399  *
1400  * Locking: called under "dev->device_lock" lock
1401  *
1402  * Return: 0 on such and error otherwise.
1403  */
1404 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1405 {
1406 	struct mei_device *dev;
1407 	int rets;
1408 
1409 	*notify_ev = false;
1410 
1411 	if (WARN_ON(!cl || !cl->dev))
1412 		return -ENODEV;
1413 
1414 	dev = cl->dev;
1415 
1416 	if (!mei_cl_is_connected(cl))
1417 		return -ENODEV;
1418 
1419 	if (cl->notify_ev)
1420 		goto out;
1421 
1422 	if (!block)
1423 		return -EAGAIN;
1424 
1425 	mutex_unlock(&dev->device_lock);
1426 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1427 	mutex_lock(&dev->device_lock);
1428 
1429 	if (rets < 0)
1430 		return rets;
1431 
1432 out:
1433 	*notify_ev = cl->notify_ev;
1434 	cl->notify_ev = false;
1435 	return 0;
1436 }
1437 
1438 /**
1439  * mei_cl_is_read_fc_cb - check if read cb is waiting for flow control
1440  *                        for given host client
1441  *
1442  * @cl: host client
1443  *
1444  * Return: true, if found at least one cb.
1445  */
1446 static bool mei_cl_is_read_fc_cb(struct mei_cl *cl)
1447 {
1448 	struct mei_device *dev = cl->dev;
1449 	struct mei_cl_cb *cb;
1450 
1451 	list_for_each_entry(cb, &dev->ctrl_wr_list.list, list)
1452 		if (cb->fop_type == MEI_FOP_READ && cb->cl == cl)
1453 			return true;
1454 	return false;
1455 }
1456 
1457 /**
1458  * mei_cl_read_start - the start read client message function.
1459  *
1460  * @cl: host client
1461  * @length: number of bytes to read
1462  * @fp: pointer to file structure
1463  *
1464  * Return: 0 on success, <0 on failure.
1465  */
1466 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1467 {
1468 	struct mei_device *dev;
1469 	struct mei_cl_cb *cb;
1470 	int rets;
1471 
1472 	if (WARN_ON(!cl || !cl->dev))
1473 		return -ENODEV;
1474 
1475 	dev = cl->dev;
1476 
1477 	if (!mei_cl_is_connected(cl))
1478 		return -ENODEV;
1479 
1480 	/* HW currently supports only one pending read */
1481 	if (!list_empty(&cl->rd_pending) || mei_cl_is_read_fc_cb(cl))
1482 		return -EBUSY;
1483 
1484 	if (!mei_me_cl_is_active(cl->me_cl)) {
1485 		cl_err(dev, cl, "no such me client\n");
1486 		return  -ENOTTY;
1487 	}
1488 
1489 	/* always allocate at least client max message */
1490 	length = max_t(size_t, length, mei_cl_mtu(cl));
1491 	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_READ, fp);
1492 	if (!cb)
1493 		return -ENOMEM;
1494 
1495 	if (mei_cl_is_fixed_address(cl)) {
1496 		list_add_tail(&cb->list, &cl->rd_pending);
1497 		return 0;
1498 	}
1499 
1500 	rets = pm_runtime_get(dev->dev);
1501 	if (rets < 0 && rets != -EINPROGRESS) {
1502 		pm_runtime_put_noidle(dev->dev);
1503 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1504 		goto nortpm;
1505 	}
1506 
1507 	if (mei_hbuf_acquire(dev)) {
1508 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1509 		if (rets < 0)
1510 			goto out;
1511 
1512 		list_add_tail(&cb->list, &cl->rd_pending);
1513 	} else {
1514 		rets = 0;
1515 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1516 	}
1517 
1518 out:
1519 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1520 	pm_runtime_mark_last_busy(dev->dev);
1521 	pm_runtime_put_autosuspend(dev->dev);
1522 nortpm:
1523 	if (rets)
1524 		mei_io_cb_free(cb);
1525 
1526 	return rets;
1527 }
1528 
1529 /**
1530  * mei_cl_irq_write - write a message to device
1531  *	from the interrupt thread context
1532  *
1533  * @cl: client
1534  * @cb: callback block.
1535  * @cmpl_list: complete list.
1536  *
1537  * Return: 0, OK; otherwise error.
1538  */
1539 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1540 		     struct mei_cl_cb *cmpl_list)
1541 {
1542 	struct mei_device *dev;
1543 	struct mei_msg_data *buf;
1544 	struct mei_msg_hdr mei_hdr;
1545 	size_t len;
1546 	u32 msg_slots;
1547 	int slots;
1548 	int rets;
1549 	bool first_chunk;
1550 
1551 	if (WARN_ON(!cl || !cl->dev))
1552 		return -ENODEV;
1553 
1554 	dev = cl->dev;
1555 
1556 	buf = &cb->buf;
1557 
1558 	first_chunk = cb->buf_idx == 0;
1559 
1560 	rets = first_chunk ? mei_cl_flow_ctrl_creds(cl, cb->fp) : 1;
1561 	if (rets < 0)
1562 		return rets;
1563 
1564 	if (rets == 0) {
1565 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1566 		return 0;
1567 	}
1568 
1569 	slots = mei_hbuf_empty_slots(dev);
1570 	len = buf->size - cb->buf_idx;
1571 	msg_slots = mei_data2slots(len);
1572 
1573 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1574 	mei_hdr.me_addr = mei_cl_me_id(cl);
1575 	mei_hdr.reserved = 0;
1576 	mei_hdr.internal = cb->internal;
1577 
1578 	if (slots >= msg_slots) {
1579 		mei_hdr.length = len;
1580 		mei_hdr.msg_complete = 1;
1581 	/* Split the message only if we can write the whole host buffer */
1582 	} else if (slots == dev->hbuf_depth) {
1583 		msg_slots = slots;
1584 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1585 		mei_hdr.length = len;
1586 		mei_hdr.msg_complete = 0;
1587 	} else {
1588 		/* wait for next time the host buffer is empty */
1589 		return 0;
1590 	}
1591 
1592 	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1593 			cb->buf.size, cb->buf_idx);
1594 
1595 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1596 	if (rets) {
1597 		cl->status = rets;
1598 		list_move_tail(&cb->list, &cmpl_list->list);
1599 		return rets;
1600 	}
1601 
1602 	cl->status = 0;
1603 	cl->writing_state = MEI_WRITING;
1604 	cb->buf_idx += mei_hdr.length;
1605 	cb->completed = mei_hdr.msg_complete == 1;
1606 
1607 	if (first_chunk) {
1608 		if (mei_cl_flow_ctrl_reduce(cl))
1609 			return -EIO;
1610 	}
1611 
1612 	if (mei_hdr.msg_complete)
1613 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
1614 
1615 	return 0;
1616 }
1617 
1618 /**
1619  * mei_cl_write - submit a write cb to mei device
1620  *	assumes device_lock is locked
1621  *
1622  * @cl: host client
1623  * @cb: write callback with filled data
1624  * @blocking: block until completed
1625  *
1626  * Return: number of bytes sent on success, <0 on failure.
1627  */
1628 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
1629 {
1630 	struct mei_device *dev;
1631 	struct mei_msg_data *buf;
1632 	struct mei_msg_hdr mei_hdr;
1633 	int size;
1634 	int rets;
1635 
1636 
1637 	if (WARN_ON(!cl || !cl->dev))
1638 		return -ENODEV;
1639 
1640 	if (WARN_ON(!cb))
1641 		return -EINVAL;
1642 
1643 	dev = cl->dev;
1644 
1645 	buf = &cb->buf;
1646 	size = buf->size;
1647 
1648 	cl_dbg(dev, cl, "size=%d\n", size);
1649 
1650 	rets = pm_runtime_get(dev->dev);
1651 	if (rets < 0 && rets != -EINPROGRESS) {
1652 		pm_runtime_put_noidle(dev->dev);
1653 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1654 		goto free;
1655 	}
1656 
1657 	cb->buf_idx = 0;
1658 	cl->writing_state = MEI_IDLE;
1659 
1660 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1661 	mei_hdr.me_addr = mei_cl_me_id(cl);
1662 	mei_hdr.reserved = 0;
1663 	mei_hdr.msg_complete = 0;
1664 	mei_hdr.internal = cb->internal;
1665 
1666 	rets = mei_cl_flow_ctrl_creds(cl, cb->fp);
1667 	if (rets < 0)
1668 		goto err;
1669 
1670 	if (rets == 0) {
1671 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1672 		rets = size;
1673 		goto out;
1674 	}
1675 	if (!mei_hbuf_acquire(dev)) {
1676 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1677 		rets = size;
1678 		goto out;
1679 	}
1680 
1681 	/* Check for a maximum length */
1682 	if (size > mei_hbuf_max_len(dev)) {
1683 		mei_hdr.length = mei_hbuf_max_len(dev);
1684 		mei_hdr.msg_complete = 0;
1685 	} else {
1686 		mei_hdr.length = size;
1687 		mei_hdr.msg_complete = 1;
1688 	}
1689 
1690 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1691 	if (rets)
1692 		goto err;
1693 
1694 	rets = mei_cl_flow_ctrl_reduce(cl);
1695 	if (rets)
1696 		goto err;
1697 
1698 	cl->writing_state = MEI_WRITING;
1699 	cb->buf_idx = mei_hdr.length;
1700 	cb->completed = mei_hdr.msg_complete == 1;
1701 
1702 out:
1703 	if (mei_hdr.msg_complete)
1704 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
1705 	else
1706 		list_add_tail(&cb->list, &dev->write_list.list);
1707 
1708 	cb = NULL;
1709 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1710 
1711 		mutex_unlock(&dev->device_lock);
1712 		rets = wait_event_interruptible(cl->tx_wait,
1713 				cl->writing_state == MEI_WRITE_COMPLETE ||
1714 				(!mei_cl_is_connected(cl)));
1715 		mutex_lock(&dev->device_lock);
1716 		/* wait_event_interruptible returns -ERESTARTSYS */
1717 		if (rets) {
1718 			if (signal_pending(current))
1719 				rets = -EINTR;
1720 			goto err;
1721 		}
1722 		if (cl->writing_state != MEI_WRITE_COMPLETE) {
1723 			rets = -EFAULT;
1724 			goto err;
1725 		}
1726 	}
1727 
1728 	rets = size;
1729 err:
1730 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1731 	pm_runtime_mark_last_busy(dev->dev);
1732 	pm_runtime_put_autosuspend(dev->dev);
1733 free:
1734 	mei_io_cb_free(cb);
1735 
1736 	return rets;
1737 }
1738 
1739 
1740 /**
1741  * mei_cl_complete - processes completed operation for a client
1742  *
1743  * @cl: private data of the file object.
1744  * @cb: callback block.
1745  */
1746 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1747 {
1748 	struct mei_device *dev = cl->dev;
1749 
1750 	switch (cb->fop_type) {
1751 	case MEI_FOP_WRITE:
1752 		mei_io_cb_free(cb);
1753 		cl->writing_state = MEI_WRITE_COMPLETE;
1754 		if (waitqueue_active(&cl->tx_wait)) {
1755 			wake_up_interruptible(&cl->tx_wait);
1756 		} else {
1757 			pm_runtime_mark_last_busy(dev->dev);
1758 			pm_request_autosuspend(dev->dev);
1759 		}
1760 		break;
1761 
1762 	case MEI_FOP_READ:
1763 		list_add_tail(&cb->list, &cl->rd_completed);
1764 		if (!mei_cl_bus_rx_event(cl))
1765 			wake_up_interruptible(&cl->rx_wait);
1766 		break;
1767 
1768 	case MEI_FOP_CONNECT:
1769 	case MEI_FOP_DISCONNECT:
1770 	case MEI_FOP_NOTIFY_STOP:
1771 	case MEI_FOP_NOTIFY_START:
1772 		if (waitqueue_active(&cl->wait))
1773 			wake_up(&cl->wait);
1774 
1775 		break;
1776 	case MEI_FOP_DISCONNECT_RSP:
1777 		mei_io_cb_free(cb);
1778 		mei_cl_set_disconnected(cl);
1779 		break;
1780 	default:
1781 		BUG_ON(0);
1782 	}
1783 }
1784 
1785 
1786 /**
1787  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1788  *
1789  * @dev: mei device
1790  */
1791 void mei_cl_all_disconnect(struct mei_device *dev)
1792 {
1793 	struct mei_cl *cl;
1794 
1795 	list_for_each_entry(cl, &dev->file_list, link)
1796 		mei_cl_set_disconnected(cl);
1797 }
1798