xref: /linux/drivers/misc/mei/client.c (revision a808c80c)
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_cl_alloc_cb - a convenient wrapper for allocating read cb
424  *
425  * @cl: host client
426  * @length: size of the buffer
427  * @type: operation type
428  * @fp: associated file pointer (might be NULL)
429  *
430  * Return: cb on success and NULL on failure
431  */
432 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
433 				  enum mei_cb_file_ops type,
434 				  const struct file *fp)
435 {
436 	struct mei_cl_cb *cb;
437 
438 	cb = mei_io_cb_init(cl, type, fp);
439 	if (!cb)
440 		return NULL;
441 
442 	if (length == 0)
443 		return cb;
444 
445 	cb->buf.data = kmalloc(length, GFP_KERNEL);
446 	if (!cb->buf.data) {
447 		mei_io_cb_free(cb);
448 		return NULL;
449 	}
450 	cb->buf.size = length;
451 
452 	return cb;
453 }
454 
455 /**
456  * mei_cl_read_cb - find this cl's callback in the read list
457  *     for a specific file
458  *
459  * @cl: host client
460  * @fp: file pointer (matching cb file object), may be NULL
461  *
462  * Return: cb on success, NULL if cb is not found
463  */
464 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
465 {
466 	struct mei_cl_cb *cb;
467 
468 	list_for_each_entry(cb, &cl->rd_completed, list)
469 		if (!fp || fp == cb->fp)
470 			return cb;
471 
472 	return NULL;
473 }
474 
475 /**
476  * mei_cl_read_cb_flush - free client's read pending and completed cbs
477  *   for a specific file
478  *
479  * @cl: host client
480  * @fp: file pointer (matching cb file object), may be NULL
481  */
482 void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp)
483 {
484 	struct mei_cl_cb *cb, *next;
485 
486 	list_for_each_entry_safe(cb, next, &cl->rd_completed, list)
487 		if (!fp || fp == cb->fp)
488 			mei_io_cb_free(cb);
489 
490 
491 	list_for_each_entry_safe(cb, next, &cl->rd_pending, list)
492 		if (!fp || fp == cb->fp)
493 			mei_io_cb_free(cb);
494 }
495 
496 /**
497  * mei_cl_flush_queues - flushes queue lists belonging to cl.
498  *
499  * @cl: host client
500  * @fp: file pointer (matching cb file object), may be NULL
501  *
502  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
503  */
504 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
505 {
506 	struct mei_device *dev;
507 
508 	if (WARN_ON(!cl || !cl->dev))
509 		return -EINVAL;
510 
511 	dev = cl->dev;
512 
513 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
514 	mei_io_list_free(&cl->dev->write_list, cl);
515 	mei_io_list_free(&cl->dev->write_waiting_list, cl);
516 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
517 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
518 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
519 
520 	mei_cl_read_cb_flush(cl, fp);
521 
522 	return 0;
523 }
524 
525 
526 /**
527  * mei_cl_init - initializes cl.
528  *
529  * @cl: host client to be initialized
530  * @dev: mei device
531  */
532 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
533 {
534 	memset(cl, 0, sizeof(struct mei_cl));
535 	init_waitqueue_head(&cl->wait);
536 	init_waitqueue_head(&cl->rx_wait);
537 	init_waitqueue_head(&cl->tx_wait);
538 	init_waitqueue_head(&cl->ev_wait);
539 	INIT_LIST_HEAD(&cl->rd_completed);
540 	INIT_LIST_HEAD(&cl->rd_pending);
541 	INIT_LIST_HEAD(&cl->link);
542 	cl->writing_state = MEI_IDLE;
543 	cl->state = MEI_FILE_INITIALIZING;
544 	cl->dev = dev;
545 }
546 
547 /**
548  * mei_cl_allocate - allocates cl  structure and sets it up.
549  *
550  * @dev: mei device
551  * Return:  The allocated file or NULL on failure
552  */
553 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
554 {
555 	struct mei_cl *cl;
556 
557 	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
558 	if (!cl)
559 		return NULL;
560 
561 	mei_cl_init(cl, dev);
562 
563 	return cl;
564 }
565 
566 /**
567  * mei_cl_link - allocate host id in the host map
568  *
569  * @cl: host client
570  *
571  * Return: 0 on success
572  *	-EINVAL on incorrect values
573  *	-EMFILE if open count exceeded.
574  */
575 int mei_cl_link(struct mei_cl *cl)
576 {
577 	struct mei_device *dev;
578 	long open_handle_count;
579 	int id;
580 
581 	if (WARN_ON(!cl || !cl->dev))
582 		return -EINVAL;
583 
584 	dev = cl->dev;
585 
586 	id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
587 	if (id >= MEI_CLIENTS_MAX) {
588 		dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
589 		return -EMFILE;
590 	}
591 
592 	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
593 	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
594 		dev_err(dev->dev, "open_handle_count exceeded %d",
595 			MEI_MAX_OPEN_HANDLE_COUNT);
596 		return -EMFILE;
597 	}
598 
599 	dev->open_handle_count++;
600 
601 	cl->host_client_id = id;
602 	list_add_tail(&cl->link, &dev->file_list);
603 
604 	set_bit(id, dev->host_clients_map);
605 
606 	cl->state = MEI_FILE_INITIALIZING;
607 
608 	cl_dbg(dev, cl, "link cl\n");
609 	return 0;
610 }
611 
612 /**
613  * mei_cl_unlink - remove host client from the list
614  *
615  * @cl: host client
616  *
617  * Return: always 0
618  */
619 int mei_cl_unlink(struct mei_cl *cl)
620 {
621 	struct mei_device *dev;
622 
623 	/* don't shout on error exit path */
624 	if (!cl)
625 		return 0;
626 
627 	/* amthif might not be initialized */
628 	if (!cl->dev)
629 		return 0;
630 
631 	dev = cl->dev;
632 
633 	cl_dbg(dev, cl, "unlink client");
634 
635 	if (dev->open_handle_count > 0)
636 		dev->open_handle_count--;
637 
638 	/* never clear the 0 bit */
639 	if (cl->host_client_id)
640 		clear_bit(cl->host_client_id, dev->host_clients_map);
641 
642 	list_del_init(&cl->link);
643 
644 	cl->state = MEI_FILE_INITIALIZING;
645 
646 	return 0;
647 }
648 
649 void mei_host_client_init(struct mei_device *dev)
650 {
651 	dev->dev_state = MEI_DEV_ENABLED;
652 	dev->reset_count = 0;
653 
654 	schedule_work(&dev->bus_rescan_work);
655 
656 	pm_runtime_mark_last_busy(dev->dev);
657 	dev_dbg(dev->dev, "rpm: autosuspend\n");
658 	pm_runtime_autosuspend(dev->dev);
659 }
660 
661 /**
662  * mei_hbuf_acquire - try to acquire host buffer
663  *
664  * @dev: the device structure
665  * Return: true if host buffer was acquired
666  */
667 bool mei_hbuf_acquire(struct mei_device *dev)
668 {
669 	if (mei_pg_state(dev) == MEI_PG_ON ||
670 	    mei_pg_in_transition(dev)) {
671 		dev_dbg(dev->dev, "device is in pg\n");
672 		return false;
673 	}
674 
675 	if (!dev->hbuf_is_ready) {
676 		dev_dbg(dev->dev, "hbuf is not ready\n");
677 		return false;
678 	}
679 
680 	dev->hbuf_is_ready = false;
681 
682 	return true;
683 }
684 
685 /**
686  * mei_cl_wake_all - wake up readers, writers and event waiters so
687  *                 they can be interrupted
688  *
689  * @cl: host client
690  */
691 static void mei_cl_wake_all(struct mei_cl *cl)
692 {
693 	struct mei_device *dev = cl->dev;
694 
695 	/* synchronized under device mutex */
696 	if (waitqueue_active(&cl->rx_wait)) {
697 		cl_dbg(dev, cl, "Waking up reading client!\n");
698 		wake_up_interruptible(&cl->rx_wait);
699 	}
700 	/* synchronized under device mutex */
701 	if (waitqueue_active(&cl->tx_wait)) {
702 		cl_dbg(dev, cl, "Waking up writing client!\n");
703 		wake_up_interruptible(&cl->tx_wait);
704 	}
705 	/* synchronized under device mutex */
706 	if (waitqueue_active(&cl->ev_wait)) {
707 		cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
708 		wake_up_interruptible(&cl->ev_wait);
709 	}
710 	/* synchronized under device mutex */
711 	if (waitqueue_active(&cl->wait)) {
712 		cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
713 		wake_up(&cl->wait);
714 	}
715 }
716 
717 /**
718  * mei_cl_set_disconnected - set disconnected state and clear
719  *   associated states and resources
720  *
721  * @cl: host client
722  */
723 void mei_cl_set_disconnected(struct mei_cl *cl)
724 {
725 	struct mei_device *dev = cl->dev;
726 
727 	if (cl->state == MEI_FILE_DISCONNECTED ||
728 	    cl->state == MEI_FILE_INITIALIZING)
729 		return;
730 
731 	cl->state = MEI_FILE_DISCONNECTED;
732 	mei_io_list_free(&dev->write_list, cl);
733 	mei_io_list_free(&dev->write_waiting_list, cl);
734 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
735 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
736 	mei_cl_wake_all(cl);
737 	cl->mei_flow_ctrl_creds = 0;
738 	cl->timer_count = 0;
739 
740 	if (!cl->me_cl)
741 		return;
742 
743 	if (!WARN_ON(cl->me_cl->connect_count == 0))
744 		cl->me_cl->connect_count--;
745 
746 	if (cl->me_cl->connect_count == 0)
747 		cl->me_cl->mei_flow_ctrl_creds = 0;
748 
749 	mei_me_cl_put(cl->me_cl);
750 	cl->me_cl = NULL;
751 }
752 
753 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
754 {
755 	if (!mei_me_cl_get(me_cl))
756 		return -ENOENT;
757 
758 	/* only one connection is allowed for fixed address clients */
759 	if (me_cl->props.fixed_address) {
760 		if (me_cl->connect_count) {
761 			mei_me_cl_put(me_cl);
762 			return -EBUSY;
763 		}
764 	}
765 
766 	cl->me_cl = me_cl;
767 	cl->state = MEI_FILE_CONNECTING;
768 	cl->me_cl->connect_count++;
769 
770 	return 0;
771 }
772 
773 /*
774  * mei_cl_send_disconnect - send disconnect request
775  *
776  * @cl: host client
777  * @cb: callback block
778  *
779  * Return: 0, OK; otherwise, error.
780  */
781 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
782 {
783 	struct mei_device *dev;
784 	int ret;
785 
786 	dev = cl->dev;
787 
788 	ret = mei_hbm_cl_disconnect_req(dev, cl);
789 	cl->status = ret;
790 	if (ret) {
791 		cl->state = MEI_FILE_DISCONNECT_REPLY;
792 		return ret;
793 	}
794 
795 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
796 	cl->timer_count = MEI_CONNECT_TIMEOUT;
797 
798 	return 0;
799 }
800 
801 /**
802  * mei_cl_irq_disconnect - processes close related operation from
803  *	interrupt thread context - send disconnect request
804  *
805  * @cl: client
806  * @cb: callback block.
807  * @cmpl_list: complete list.
808  *
809  * Return: 0, OK; otherwise, error.
810  */
811 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
812 			    struct mei_cl_cb *cmpl_list)
813 {
814 	struct mei_device *dev = cl->dev;
815 	u32 msg_slots;
816 	int slots;
817 	int ret;
818 
819 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
820 	slots = mei_hbuf_empty_slots(dev);
821 
822 	if (slots < msg_slots)
823 		return -EMSGSIZE;
824 
825 	ret = mei_cl_send_disconnect(cl, cb);
826 	if (ret)
827 		list_move_tail(&cb->list, &cmpl_list->list);
828 
829 	return ret;
830 }
831 
832 /**
833  * __mei_cl_disconnect - disconnect host client from the me one
834  *     internal function runtime pm has to be already acquired
835  *
836  * @cl: host client
837  *
838  * Return: 0 on success, <0 on failure.
839  */
840 static int __mei_cl_disconnect(struct mei_cl *cl)
841 {
842 	struct mei_device *dev;
843 	struct mei_cl_cb *cb;
844 	int rets;
845 
846 	dev = cl->dev;
847 
848 	cl->state = MEI_FILE_DISCONNECTING;
849 
850 	cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT, NULL);
851 	rets = cb ? 0 : -ENOMEM;
852 	if (rets)
853 		goto out;
854 
855 	cl_dbg(dev, cl, "add disconnect cb to control write list\n");
856 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
857 
858 	if (mei_hbuf_acquire(dev)) {
859 		rets = mei_cl_send_disconnect(cl, cb);
860 		if (rets) {
861 			cl_err(dev, cl, "failed to disconnect.\n");
862 			goto out;
863 		}
864 	}
865 
866 	mutex_unlock(&dev->device_lock);
867 	wait_event_timeout(cl->wait,
868 			   cl->state == MEI_FILE_DISCONNECT_REPLY ||
869 			   cl->state == MEI_FILE_DISCONNECTED,
870 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
871 	mutex_lock(&dev->device_lock);
872 
873 	rets = cl->status;
874 	if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
875 	    cl->state != MEI_FILE_DISCONNECTED) {
876 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
877 		rets = -ETIME;
878 	}
879 
880 out:
881 	/* we disconnect also on error */
882 	mei_cl_set_disconnected(cl);
883 	if (!rets)
884 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
885 
886 	mei_io_cb_free(cb);
887 	return rets;
888 }
889 
890 /**
891  * mei_cl_disconnect - disconnect host client from the me one
892  *
893  * @cl: host client
894  *
895  * Locking: called under "dev->device_lock" lock
896  *
897  * Return: 0 on success, <0 on failure.
898  */
899 int mei_cl_disconnect(struct mei_cl *cl)
900 {
901 	struct mei_device *dev;
902 	int rets;
903 
904 	if (WARN_ON(!cl || !cl->dev))
905 		return -ENODEV;
906 
907 	dev = cl->dev;
908 
909 	cl_dbg(dev, cl, "disconnecting");
910 
911 	if (!mei_cl_is_connected(cl))
912 		return 0;
913 
914 	if (mei_cl_is_fixed_address(cl)) {
915 		mei_cl_set_disconnected(cl);
916 		return 0;
917 	}
918 
919 	rets = pm_runtime_get(dev->dev);
920 	if (rets < 0 && rets != -EINPROGRESS) {
921 		pm_runtime_put_noidle(dev->dev);
922 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
923 		return rets;
924 	}
925 
926 	rets = __mei_cl_disconnect(cl);
927 
928 	cl_dbg(dev, cl, "rpm: autosuspend\n");
929 	pm_runtime_mark_last_busy(dev->dev);
930 	pm_runtime_put_autosuspend(dev->dev);
931 
932 	return rets;
933 }
934 
935 
936 /**
937  * mei_cl_is_other_connecting - checks if other
938  *    client with the same me client id is connecting
939  *
940  * @cl: private data of the file object
941  *
942  * Return: true if other client is connected, false - otherwise.
943  */
944 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
945 {
946 	struct mei_device *dev;
947 	struct mei_cl_cb *cb;
948 
949 	dev = cl->dev;
950 
951 	list_for_each_entry(cb, &dev->ctrl_rd_list.list, list) {
952 		if (cb->fop_type == MEI_FOP_CONNECT &&
953 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
954 			return true;
955 	}
956 
957 	return false;
958 }
959 
960 /**
961  * mei_cl_send_connect - send connect request
962  *
963  * @cl: host client
964  * @cb: callback block
965  *
966  * Return: 0, OK; otherwise, error.
967  */
968 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
969 {
970 	struct mei_device *dev;
971 	int ret;
972 
973 	dev = cl->dev;
974 
975 	ret = mei_hbm_cl_connect_req(dev, cl);
976 	cl->status = ret;
977 	if (ret) {
978 		cl->state = MEI_FILE_DISCONNECT_REPLY;
979 		return ret;
980 	}
981 
982 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
983 	cl->timer_count = MEI_CONNECT_TIMEOUT;
984 	return 0;
985 }
986 
987 /**
988  * mei_cl_irq_connect - send connect request in irq_thread context
989  *
990  * @cl: host client
991  * @cb: callback block
992  * @cmpl_list: complete list
993  *
994  * Return: 0, OK; otherwise, error.
995  */
996 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
997 			      struct mei_cl_cb *cmpl_list)
998 {
999 	struct mei_device *dev = cl->dev;
1000 	u32 msg_slots;
1001 	int slots;
1002 	int rets;
1003 
1004 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1005 	slots = mei_hbuf_empty_slots(dev);
1006 
1007 	if (mei_cl_is_other_connecting(cl))
1008 		return 0;
1009 
1010 	if (slots < msg_slots)
1011 		return -EMSGSIZE;
1012 
1013 	rets = mei_cl_send_connect(cl, cb);
1014 	if (rets)
1015 		list_move_tail(&cb->list, &cmpl_list->list);
1016 
1017 	return rets;
1018 }
1019 
1020 /**
1021  * mei_cl_connect - connect host client to the me one
1022  *
1023  * @cl: host client
1024  * @me_cl: me client
1025  * @file: pointer to file structure
1026  *
1027  * Locking: called under "dev->device_lock" lock
1028  *
1029  * Return: 0 on success, <0 on failure.
1030  */
1031 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1032 		  const struct file *file)
1033 {
1034 	struct mei_device *dev;
1035 	struct mei_cl_cb *cb;
1036 	int rets;
1037 
1038 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1039 		return -ENODEV;
1040 
1041 	dev = cl->dev;
1042 
1043 	rets = mei_cl_set_connecting(cl, me_cl);
1044 	if (rets)
1045 		return rets;
1046 
1047 	if (mei_cl_is_fixed_address(cl)) {
1048 		cl->state = MEI_FILE_CONNECTED;
1049 		return 0;
1050 	}
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 		goto nortpm;
1057 	}
1058 
1059 	cb = mei_io_cb_init(cl, MEI_FOP_CONNECT, file);
1060 	rets = cb ? 0 : -ENOMEM;
1061 	if (rets)
1062 		goto out;
1063 
1064 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1065 
1066 	/* run hbuf acquire last so we don't have to undo */
1067 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1068 		rets = mei_cl_send_connect(cl, cb);
1069 		if (rets)
1070 			goto out;
1071 	}
1072 
1073 	mutex_unlock(&dev->device_lock);
1074 	wait_event_timeout(cl->wait,
1075 			(cl->state == MEI_FILE_CONNECTED ||
1076 			 cl->state == MEI_FILE_DISCONNECTED ||
1077 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1078 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1079 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1080 	mutex_lock(&dev->device_lock);
1081 
1082 	if (!mei_cl_is_connected(cl)) {
1083 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1084 			mei_io_list_flush(&dev->ctrl_rd_list, cl);
1085 			mei_io_list_flush(&dev->ctrl_wr_list, cl);
1086 			 /* ignore disconnect return valuue;
1087 			  * in case of failure reset will be invoked
1088 			  */
1089 			__mei_cl_disconnect(cl);
1090 			rets = -EFAULT;
1091 			goto out;
1092 		}
1093 
1094 		/* timeout or something went really wrong */
1095 		if (!cl->status)
1096 			cl->status = -EFAULT;
1097 	}
1098 
1099 	rets = cl->status;
1100 out:
1101 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1102 	pm_runtime_mark_last_busy(dev->dev);
1103 	pm_runtime_put_autosuspend(dev->dev);
1104 
1105 	mei_io_cb_free(cb);
1106 
1107 nortpm:
1108 	if (!mei_cl_is_connected(cl))
1109 		mei_cl_set_disconnected(cl);
1110 
1111 	return rets;
1112 }
1113 
1114 /**
1115  * mei_cl_alloc_linked - allocate and link host client
1116  *
1117  * @dev: the device structure
1118  *
1119  * Return: cl on success ERR_PTR on failure
1120  */
1121 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1122 {
1123 	struct mei_cl *cl;
1124 	int ret;
1125 
1126 	cl = mei_cl_allocate(dev);
1127 	if (!cl) {
1128 		ret = -ENOMEM;
1129 		goto err;
1130 	}
1131 
1132 	ret = mei_cl_link(cl);
1133 	if (ret)
1134 		goto err;
1135 
1136 	return cl;
1137 err:
1138 	kfree(cl);
1139 	return ERR_PTR(ret);
1140 }
1141 
1142 
1143 
1144 /**
1145  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
1146  *
1147  * @cl: host client
1148  *
1149  * Return: 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
1150  */
1151 static int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
1152 {
1153 	if (WARN_ON(!cl || !cl->me_cl))
1154 		return -EINVAL;
1155 
1156 	if (cl->mei_flow_ctrl_creds > 0)
1157 		return 1;
1158 
1159 	if (mei_cl_is_fixed_address(cl))
1160 		return 1;
1161 
1162 	if (mei_cl_is_single_recv_buf(cl)) {
1163 		if (cl->me_cl->mei_flow_ctrl_creds > 0)
1164 			return 1;
1165 	}
1166 	return 0;
1167 }
1168 
1169 /**
1170  * mei_cl_flow_ctrl_reduce - reduces flow_control.
1171  *
1172  * @cl: private data of the file object
1173  *
1174  * Return:
1175  *	0 on success
1176  *	-EINVAL when ctrl credits are <= 0
1177  */
1178 static int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
1179 {
1180 	if (WARN_ON(!cl || !cl->me_cl))
1181 		return -EINVAL;
1182 
1183 	if (mei_cl_is_fixed_address(cl))
1184 		return 0;
1185 
1186 	if (mei_cl_is_single_recv_buf(cl)) {
1187 		if (WARN_ON(cl->me_cl->mei_flow_ctrl_creds <= 0))
1188 			return -EINVAL;
1189 		cl->me_cl->mei_flow_ctrl_creds--;
1190 	} else {
1191 		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
1192 			return -EINVAL;
1193 		cl->mei_flow_ctrl_creds--;
1194 	}
1195 	return 0;
1196 }
1197 
1198 /**
1199  *  mei_cl_notify_fop2req - convert fop to proper request
1200  *
1201  * @fop: client notification start response command
1202  *
1203  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1204  */
1205 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1206 {
1207 	if (fop == MEI_FOP_NOTIFY_START)
1208 		return MEI_HBM_NOTIFICATION_START;
1209 	else
1210 		return MEI_HBM_NOTIFICATION_STOP;
1211 }
1212 
1213 /**
1214  *  mei_cl_notify_req2fop - convert notification request top file operation type
1215  *
1216  * @req: hbm notification request type
1217  *
1218  * Return:  MEI_FOP_NOTIFY_START/STOP
1219  */
1220 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1221 {
1222 	if (req == MEI_HBM_NOTIFICATION_START)
1223 		return MEI_FOP_NOTIFY_START;
1224 	else
1225 		return MEI_FOP_NOTIFY_STOP;
1226 }
1227 
1228 /**
1229  * mei_cl_irq_notify - send notification request in irq_thread context
1230  *
1231  * @cl: client
1232  * @cb: callback block.
1233  * @cmpl_list: complete list.
1234  *
1235  * Return: 0 on such and error otherwise.
1236  */
1237 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1238 		      struct mei_cl_cb *cmpl_list)
1239 {
1240 	struct mei_device *dev = cl->dev;
1241 	u32 msg_slots;
1242 	int slots;
1243 	int ret;
1244 	bool request;
1245 
1246 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1247 	slots = mei_hbuf_empty_slots(dev);
1248 
1249 	if (slots < msg_slots)
1250 		return -EMSGSIZE;
1251 
1252 	request = mei_cl_notify_fop2req(cb->fop_type);
1253 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1254 	if (ret) {
1255 		cl->status = ret;
1256 		list_move_tail(&cb->list, &cmpl_list->list);
1257 		return ret;
1258 	}
1259 
1260 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1261 	return 0;
1262 }
1263 
1264 /**
1265  * mei_cl_notify_request - send notification stop/start request
1266  *
1267  * @cl: host client
1268  * @file: associate request with file
1269  * @request: 1 for start or 0 for stop
1270  *
1271  * Locking: called under "dev->device_lock" lock
1272  *
1273  * Return: 0 on such and error otherwise.
1274  */
1275 int mei_cl_notify_request(struct mei_cl *cl,
1276 			  const struct file *file, u8 request)
1277 {
1278 	struct mei_device *dev;
1279 	struct mei_cl_cb *cb;
1280 	enum mei_cb_file_ops fop_type;
1281 	int rets;
1282 
1283 	if (WARN_ON(!cl || !cl->dev))
1284 		return -ENODEV;
1285 
1286 	dev = cl->dev;
1287 
1288 	if (!dev->hbm_f_ev_supported) {
1289 		cl_dbg(dev, cl, "notifications not supported\n");
1290 		return -EOPNOTSUPP;
1291 	}
1292 
1293 	rets = pm_runtime_get(dev->dev);
1294 	if (rets < 0 && rets != -EINPROGRESS) {
1295 		pm_runtime_put_noidle(dev->dev);
1296 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1297 		return rets;
1298 	}
1299 
1300 	fop_type = mei_cl_notify_req2fop(request);
1301 	cb = mei_io_cb_init(cl, fop_type, file);
1302 	if (!cb) {
1303 		rets = -ENOMEM;
1304 		goto out;
1305 	}
1306 
1307 	if (mei_hbuf_acquire(dev)) {
1308 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1309 			rets = -ENODEV;
1310 			goto out;
1311 		}
1312 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
1313 	} else {
1314 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1315 	}
1316 
1317 	mutex_unlock(&dev->device_lock);
1318 	wait_event_timeout(cl->wait,
1319 			   cl->notify_en == request || !mei_cl_is_connected(cl),
1320 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1321 	mutex_lock(&dev->device_lock);
1322 
1323 	if (cl->notify_en != request && !cl->status)
1324 		cl->status = -EFAULT;
1325 
1326 	rets = cl->status;
1327 
1328 out:
1329 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1330 	pm_runtime_mark_last_busy(dev->dev);
1331 	pm_runtime_put_autosuspend(dev->dev);
1332 
1333 	mei_io_cb_free(cb);
1334 	return rets;
1335 }
1336 
1337 /**
1338  * mei_cl_notify - raise notification
1339  *
1340  * @cl: host client
1341  *
1342  * Locking: called under "dev->device_lock" lock
1343  */
1344 void mei_cl_notify(struct mei_cl *cl)
1345 {
1346 	struct mei_device *dev;
1347 
1348 	if (!cl || !cl->dev)
1349 		return;
1350 
1351 	dev = cl->dev;
1352 
1353 	if (!cl->notify_en)
1354 		return;
1355 
1356 	cl_dbg(dev, cl, "notify event");
1357 	cl->notify_ev = true;
1358 	if (!mei_cl_bus_notify_event(cl))
1359 		wake_up_interruptible(&cl->ev_wait);
1360 
1361 	if (cl->ev_async)
1362 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1363 
1364 }
1365 
1366 /**
1367  * mei_cl_notify_get - get or wait for notification event
1368  *
1369  * @cl: host client
1370  * @block: this request is blocking
1371  * @notify_ev: true if notification event was received
1372  *
1373  * Locking: called under "dev->device_lock" lock
1374  *
1375  * Return: 0 on such and error otherwise.
1376  */
1377 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1378 {
1379 	struct mei_device *dev;
1380 	int rets;
1381 
1382 	*notify_ev = false;
1383 
1384 	if (WARN_ON(!cl || !cl->dev))
1385 		return -ENODEV;
1386 
1387 	dev = cl->dev;
1388 
1389 	if (!mei_cl_is_connected(cl))
1390 		return -ENODEV;
1391 
1392 	if (cl->notify_ev)
1393 		goto out;
1394 
1395 	if (!block)
1396 		return -EAGAIN;
1397 
1398 	mutex_unlock(&dev->device_lock);
1399 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1400 	mutex_lock(&dev->device_lock);
1401 
1402 	if (rets < 0)
1403 		return rets;
1404 
1405 out:
1406 	*notify_ev = cl->notify_ev;
1407 	cl->notify_ev = false;
1408 	return 0;
1409 }
1410 
1411 /**
1412  * mei_cl_is_read_fc_cb - check if read cb is waiting for flow control
1413  *                        for given host client
1414  *
1415  * @cl: host client
1416  *
1417  * Return: true, if found at least one cb.
1418  */
1419 static bool mei_cl_is_read_fc_cb(struct mei_cl *cl)
1420 {
1421 	struct mei_device *dev = cl->dev;
1422 	struct mei_cl_cb *cb;
1423 
1424 	list_for_each_entry(cb, &dev->ctrl_wr_list.list, list)
1425 		if (cb->fop_type == MEI_FOP_READ && cb->cl == cl)
1426 			return true;
1427 	return false;
1428 }
1429 
1430 /**
1431  * mei_cl_read_start - the start read client message function.
1432  *
1433  * @cl: host client
1434  * @length: number of bytes to read
1435  * @fp: pointer to file structure
1436  *
1437  * Return: 0 on success, <0 on failure.
1438  */
1439 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1440 {
1441 	struct mei_device *dev;
1442 	struct mei_cl_cb *cb;
1443 	int rets;
1444 
1445 	if (WARN_ON(!cl || !cl->dev))
1446 		return -ENODEV;
1447 
1448 	dev = cl->dev;
1449 
1450 	if (!mei_cl_is_connected(cl))
1451 		return -ENODEV;
1452 
1453 	/* HW currently supports only one pending read */
1454 	if (!list_empty(&cl->rd_pending) || mei_cl_is_read_fc_cb(cl))
1455 		return -EBUSY;
1456 
1457 	if (!mei_me_cl_is_active(cl->me_cl)) {
1458 		cl_err(dev, cl, "no such me client\n");
1459 		return  -ENOTTY;
1460 	}
1461 
1462 	/* always allocate at least client max message */
1463 	length = max_t(size_t, length, mei_cl_mtu(cl));
1464 	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_READ, fp);
1465 	if (!cb)
1466 		return -ENOMEM;
1467 
1468 	if (mei_cl_is_fixed_address(cl)) {
1469 		list_add_tail(&cb->list, &cl->rd_pending);
1470 		return 0;
1471 	}
1472 
1473 	rets = pm_runtime_get(dev->dev);
1474 	if (rets < 0 && rets != -EINPROGRESS) {
1475 		pm_runtime_put_noidle(dev->dev);
1476 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1477 		goto nortpm;
1478 	}
1479 
1480 	if (mei_hbuf_acquire(dev)) {
1481 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1482 		if (rets < 0)
1483 			goto out;
1484 
1485 		list_add_tail(&cb->list, &cl->rd_pending);
1486 	} else {
1487 		rets = 0;
1488 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1489 	}
1490 
1491 out:
1492 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1493 	pm_runtime_mark_last_busy(dev->dev);
1494 	pm_runtime_put_autosuspend(dev->dev);
1495 nortpm:
1496 	if (rets)
1497 		mei_io_cb_free(cb);
1498 
1499 	return rets;
1500 }
1501 
1502 /**
1503  * mei_cl_irq_write - write a message to device
1504  *	from the interrupt thread context
1505  *
1506  * @cl: client
1507  * @cb: callback block.
1508  * @cmpl_list: complete list.
1509  *
1510  * Return: 0, OK; otherwise error.
1511  */
1512 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1513 		     struct mei_cl_cb *cmpl_list)
1514 {
1515 	struct mei_device *dev;
1516 	struct mei_msg_data *buf;
1517 	struct mei_msg_hdr mei_hdr;
1518 	size_t len;
1519 	u32 msg_slots;
1520 	int slots;
1521 	int rets;
1522 	bool first_chunk;
1523 
1524 	if (WARN_ON(!cl || !cl->dev))
1525 		return -ENODEV;
1526 
1527 	dev = cl->dev;
1528 
1529 	buf = &cb->buf;
1530 
1531 	first_chunk = cb->buf_idx == 0;
1532 
1533 	rets = first_chunk ? mei_cl_flow_ctrl_creds(cl) : 1;
1534 	if (rets < 0)
1535 		return rets;
1536 
1537 	if (rets == 0) {
1538 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1539 		return 0;
1540 	}
1541 
1542 	slots = mei_hbuf_empty_slots(dev);
1543 	len = buf->size - cb->buf_idx;
1544 	msg_slots = mei_data2slots(len);
1545 
1546 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1547 	mei_hdr.me_addr = mei_cl_me_id(cl);
1548 	mei_hdr.reserved = 0;
1549 	mei_hdr.internal = cb->internal;
1550 
1551 	if (slots >= msg_slots) {
1552 		mei_hdr.length = len;
1553 		mei_hdr.msg_complete = 1;
1554 	/* Split the message only if we can write the whole host buffer */
1555 	} else if (slots == dev->hbuf_depth) {
1556 		msg_slots = slots;
1557 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1558 		mei_hdr.length = len;
1559 		mei_hdr.msg_complete = 0;
1560 	} else {
1561 		/* wait for next time the host buffer is empty */
1562 		return 0;
1563 	}
1564 
1565 	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1566 			cb->buf.size, cb->buf_idx);
1567 
1568 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1569 	if (rets) {
1570 		cl->status = rets;
1571 		list_move_tail(&cb->list, &cmpl_list->list);
1572 		return rets;
1573 	}
1574 
1575 	cl->status = 0;
1576 	cl->writing_state = MEI_WRITING;
1577 	cb->buf_idx += mei_hdr.length;
1578 	cb->completed = mei_hdr.msg_complete == 1;
1579 
1580 	if (first_chunk) {
1581 		if (mei_cl_flow_ctrl_reduce(cl))
1582 			return -EIO;
1583 	}
1584 
1585 	if (mei_hdr.msg_complete)
1586 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
1587 
1588 	return 0;
1589 }
1590 
1591 /**
1592  * mei_cl_write - submit a write cb to mei device
1593  *	assumes device_lock is locked
1594  *
1595  * @cl: host client
1596  * @cb: write callback with filled data
1597  * @blocking: block until completed
1598  *
1599  * Return: number of bytes sent on success, <0 on failure.
1600  */
1601 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
1602 {
1603 	struct mei_device *dev;
1604 	struct mei_msg_data *buf;
1605 	struct mei_msg_hdr mei_hdr;
1606 	int size;
1607 	int rets;
1608 
1609 
1610 	if (WARN_ON(!cl || !cl->dev))
1611 		return -ENODEV;
1612 
1613 	if (WARN_ON(!cb))
1614 		return -EINVAL;
1615 
1616 	dev = cl->dev;
1617 
1618 	buf = &cb->buf;
1619 	size = buf->size;
1620 
1621 	cl_dbg(dev, cl, "size=%d\n", size);
1622 
1623 	rets = pm_runtime_get(dev->dev);
1624 	if (rets < 0 && rets != -EINPROGRESS) {
1625 		pm_runtime_put_noidle(dev->dev);
1626 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1627 		goto free;
1628 	}
1629 
1630 	cb->buf_idx = 0;
1631 	cl->writing_state = MEI_IDLE;
1632 
1633 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1634 	mei_hdr.me_addr = mei_cl_me_id(cl);
1635 	mei_hdr.reserved = 0;
1636 	mei_hdr.msg_complete = 0;
1637 	mei_hdr.internal = cb->internal;
1638 
1639 	rets = mei_cl_flow_ctrl_creds(cl);
1640 	if (rets < 0)
1641 		goto err;
1642 
1643 	if (rets == 0) {
1644 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1645 		rets = size;
1646 		goto out;
1647 	}
1648 	if (!mei_hbuf_acquire(dev)) {
1649 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1650 		rets = size;
1651 		goto out;
1652 	}
1653 
1654 	/* Check for a maximum length */
1655 	if (size > mei_hbuf_max_len(dev)) {
1656 		mei_hdr.length = mei_hbuf_max_len(dev);
1657 		mei_hdr.msg_complete = 0;
1658 	} else {
1659 		mei_hdr.length = size;
1660 		mei_hdr.msg_complete = 1;
1661 	}
1662 
1663 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1664 	if (rets)
1665 		goto err;
1666 
1667 	rets = mei_cl_flow_ctrl_reduce(cl);
1668 	if (rets)
1669 		goto err;
1670 
1671 	cl->writing_state = MEI_WRITING;
1672 	cb->buf_idx = mei_hdr.length;
1673 	cb->completed = mei_hdr.msg_complete == 1;
1674 
1675 out:
1676 	if (mei_hdr.msg_complete)
1677 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
1678 	else
1679 		list_add_tail(&cb->list, &dev->write_list.list);
1680 
1681 	cb = NULL;
1682 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1683 
1684 		mutex_unlock(&dev->device_lock);
1685 		rets = wait_event_interruptible(cl->tx_wait,
1686 				cl->writing_state == MEI_WRITE_COMPLETE ||
1687 				(!mei_cl_is_connected(cl)));
1688 		mutex_lock(&dev->device_lock);
1689 		/* wait_event_interruptible returns -ERESTARTSYS */
1690 		if (rets) {
1691 			if (signal_pending(current))
1692 				rets = -EINTR;
1693 			goto err;
1694 		}
1695 		if (cl->writing_state != MEI_WRITE_COMPLETE) {
1696 			rets = -EFAULT;
1697 			goto err;
1698 		}
1699 	}
1700 
1701 	rets = size;
1702 err:
1703 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1704 	pm_runtime_mark_last_busy(dev->dev);
1705 	pm_runtime_put_autosuspend(dev->dev);
1706 free:
1707 	mei_io_cb_free(cb);
1708 
1709 	return rets;
1710 }
1711 
1712 
1713 /**
1714  * mei_cl_complete - processes completed operation for a client
1715  *
1716  * @cl: private data of the file object.
1717  * @cb: callback block.
1718  */
1719 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1720 {
1721 	struct mei_device *dev = cl->dev;
1722 
1723 	switch (cb->fop_type) {
1724 	case MEI_FOP_WRITE:
1725 		mei_io_cb_free(cb);
1726 		cl->writing_state = MEI_WRITE_COMPLETE;
1727 		if (waitqueue_active(&cl->tx_wait)) {
1728 			wake_up_interruptible(&cl->tx_wait);
1729 		} else {
1730 			pm_runtime_mark_last_busy(dev->dev);
1731 			pm_request_autosuspend(dev->dev);
1732 		}
1733 		break;
1734 
1735 	case MEI_FOP_READ:
1736 		list_add_tail(&cb->list, &cl->rd_completed);
1737 		if (!mei_cl_bus_rx_event(cl))
1738 			wake_up_interruptible(&cl->rx_wait);
1739 		break;
1740 
1741 	case MEI_FOP_CONNECT:
1742 	case MEI_FOP_DISCONNECT:
1743 	case MEI_FOP_NOTIFY_STOP:
1744 	case MEI_FOP_NOTIFY_START:
1745 		if (waitqueue_active(&cl->wait))
1746 			wake_up(&cl->wait);
1747 
1748 		break;
1749 	case MEI_FOP_DISCONNECT_RSP:
1750 		mei_io_cb_free(cb);
1751 		mei_cl_set_disconnected(cl);
1752 		break;
1753 	default:
1754 		BUG_ON(0);
1755 	}
1756 }
1757 
1758 
1759 /**
1760  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1761  *
1762  * @dev: mei device
1763  */
1764 void mei_cl_all_disconnect(struct mei_device *dev)
1765 {
1766 	struct mei_cl *cl;
1767 
1768 	list_for_each_entry(cl, &dev->file_list, link)
1769 		mei_cl_set_disconnected(cl);
1770 }
1771