xref: /linux/drivers/misc/mei/client.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 				 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->file_object = 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, struct file *fp)
459 {
460 	struct mei_cl_cb *cb;
461 
462 	cb = mei_io_cb_init(cl, type, fp);
463 	if (!cb)
464 		return NULL;
465 
466 	if (mei_io_cb_alloc_buf(cb, length)) {
467 		mei_io_cb_free(cb);
468 		return NULL;
469 	}
470 
471 	return cb;
472 }
473 
474 /**
475  * mei_cl_read_cb - find this cl's callback in the read list
476  *     for a specific file
477  *
478  * @cl: host client
479  * @fp: file pointer (matching cb file object), may be NULL
480  *
481  * Return: cb on success, NULL if cb is not found
482  */
483 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
484 {
485 	struct mei_cl_cb *cb;
486 
487 	list_for_each_entry(cb, &cl->rd_completed, list)
488 		if (!fp || fp == cb->file_object)
489 			return cb;
490 
491 	return NULL;
492 }
493 
494 /**
495  * mei_cl_read_cb_flush - free client's read pending and completed cbs
496  *   for a specific file
497  *
498  * @cl: host client
499  * @fp: file pointer (matching cb file object), may be NULL
500  */
501 void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp)
502 {
503 	struct mei_cl_cb *cb, *next;
504 
505 	list_for_each_entry_safe(cb, next, &cl->rd_completed, list)
506 		if (!fp || fp == cb->file_object)
507 			mei_io_cb_free(cb);
508 
509 
510 	list_for_each_entry_safe(cb, next, &cl->rd_pending, list)
511 		if (!fp || fp == cb->file_object)
512 			mei_io_cb_free(cb);
513 }
514 
515 /**
516  * mei_cl_flush_queues - flushes queue lists belonging to cl.
517  *
518  * @cl: host client
519  * @fp: file pointer (matching cb file object), may be NULL
520  *
521  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
522  */
523 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
524 {
525 	struct mei_device *dev;
526 
527 	if (WARN_ON(!cl || !cl->dev))
528 		return -EINVAL;
529 
530 	dev = cl->dev;
531 
532 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
533 	mei_io_list_free(&cl->dev->write_list, cl);
534 	mei_io_list_free(&cl->dev->write_waiting_list, cl);
535 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
536 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
537 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
538 	mei_io_list_flush(&cl->dev->amthif_rd_complete_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  * @id: fixed host id or MEI_HOST_CLIENT_ID_ANY (-1) for generic one
591  *
592  * Return: 0 on success
593  *	-EINVAL on incorrect values
594  *	-EMFILE if open count exceeded.
595  */
596 int mei_cl_link(struct mei_cl *cl, int id)
597 {
598 	struct mei_device *dev;
599 	long open_handle_count;
600 
601 	if (WARN_ON(!cl || !cl->dev))
602 		return -EINVAL;
603 
604 	dev = cl->dev;
605 
606 	/* If Id is not assigned get one*/
607 	if (id == MEI_HOST_CLIENT_ID_ANY)
608 		id = find_first_zero_bit(dev->host_clients_map,
609 					MEI_CLIENTS_MAX);
610 
611 	if (id >= MEI_CLIENTS_MAX) {
612 		dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
613 		return -EMFILE;
614 	}
615 
616 	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
617 	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
618 		dev_err(dev->dev, "open_handle_count exceeded %d",
619 			MEI_MAX_OPEN_HANDLE_COUNT);
620 		return -EMFILE;
621 	}
622 
623 	dev->open_handle_count++;
624 
625 	cl->host_client_id = id;
626 	list_add_tail(&cl->link, &dev->file_list);
627 
628 	set_bit(id, dev->host_clients_map);
629 
630 	cl->state = MEI_FILE_INITIALIZING;
631 
632 	cl_dbg(dev, cl, "link cl\n");
633 	return 0;
634 }
635 
636 /**
637  * mei_cl_unlink - remove host client from the list
638  *
639  * @cl: host client
640  *
641  * Return: always 0
642  */
643 int mei_cl_unlink(struct mei_cl *cl)
644 {
645 	struct mei_device *dev;
646 
647 	/* don't shout on error exit path */
648 	if (!cl)
649 		return 0;
650 
651 	/* wd and amthif might not be initialized */
652 	if (!cl->dev)
653 		return 0;
654 
655 	dev = cl->dev;
656 
657 	cl_dbg(dev, cl, "unlink client");
658 
659 	if (dev->open_handle_count > 0)
660 		dev->open_handle_count--;
661 
662 	/* never clear the 0 bit */
663 	if (cl->host_client_id)
664 		clear_bit(cl->host_client_id, dev->host_clients_map);
665 
666 	list_del_init(&cl->link);
667 
668 	cl->state = MEI_FILE_INITIALIZING;
669 
670 	return 0;
671 }
672 
673 
674 void mei_host_client_init(struct work_struct *work)
675 {
676 	struct mei_device *dev =
677 		container_of(work, struct mei_device, init_work);
678 	struct mei_me_client *me_cl;
679 
680 	mutex_lock(&dev->device_lock);
681 
682 
683 	me_cl = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
684 	if (me_cl)
685 		mei_amthif_host_init(dev, me_cl);
686 	mei_me_cl_put(me_cl);
687 
688 	me_cl = mei_me_cl_by_uuid(dev, &mei_wd_guid);
689 	if (me_cl)
690 		mei_wd_host_init(dev, me_cl);
691 	mei_me_cl_put(me_cl);
692 
693 	dev->dev_state = MEI_DEV_ENABLED;
694 	dev->reset_count = 0;
695 	mutex_unlock(&dev->device_lock);
696 
697 	mei_cl_bus_rescan(dev);
698 
699 	pm_runtime_mark_last_busy(dev->dev);
700 	dev_dbg(dev->dev, "rpm: autosuspend\n");
701 	pm_runtime_autosuspend(dev->dev);
702 }
703 
704 /**
705  * mei_hbuf_acquire - try to acquire host buffer
706  *
707  * @dev: the device structure
708  * Return: true if host buffer was acquired
709  */
710 bool mei_hbuf_acquire(struct mei_device *dev)
711 {
712 	if (mei_pg_state(dev) == MEI_PG_ON ||
713 	    mei_pg_in_transition(dev)) {
714 		dev_dbg(dev->dev, "device is in pg\n");
715 		return false;
716 	}
717 
718 	if (!dev->hbuf_is_ready) {
719 		dev_dbg(dev->dev, "hbuf is not ready\n");
720 		return false;
721 	}
722 
723 	dev->hbuf_is_ready = false;
724 
725 	return true;
726 }
727 
728 /**
729  * mei_cl_set_disconnected - set disconnected state and clear
730  *   associated states and resources
731  *
732  * @cl: host client
733  */
734 void mei_cl_set_disconnected(struct mei_cl *cl)
735 {
736 	struct mei_device *dev = cl->dev;
737 
738 	if (cl->state == MEI_FILE_DISCONNECTED ||
739 	    cl->state == MEI_FILE_INITIALIZING)
740 		return;
741 
742 	cl->state = MEI_FILE_DISCONNECTED;
743 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
744 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
745 	cl->mei_flow_ctrl_creds = 0;
746 	cl->timer_count = 0;
747 
748 	if (!cl->me_cl)
749 		return;
750 
751 	if (!WARN_ON(cl->me_cl->connect_count == 0))
752 		cl->me_cl->connect_count--;
753 
754 	if (cl->me_cl->connect_count == 0)
755 		cl->me_cl->mei_flow_ctrl_creds = 0;
756 
757 	mei_me_cl_put(cl->me_cl);
758 	cl->me_cl = NULL;
759 }
760 
761 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
762 {
763 	if (!mei_me_cl_get(me_cl))
764 		return -ENOENT;
765 
766 	/* only one connection is allowed for fixed address clients */
767 	if (me_cl->props.fixed_address) {
768 		if (me_cl->connect_count) {
769 			mei_me_cl_put(me_cl);
770 			return -EBUSY;
771 		}
772 	}
773 
774 	cl->me_cl = me_cl;
775 	cl->state = MEI_FILE_CONNECTING;
776 	cl->me_cl->connect_count++;
777 
778 	return 0;
779 }
780 
781 /*
782  * mei_cl_send_disconnect - send disconnect request
783  *
784  * @cl: host client
785  * @cb: callback block
786  *
787  * Return: 0, OK; otherwise, error.
788  */
789 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
790 {
791 	struct mei_device *dev;
792 	int ret;
793 
794 	dev = cl->dev;
795 
796 	ret = mei_hbm_cl_disconnect_req(dev, cl);
797 	cl->status = ret;
798 	if (ret) {
799 		cl->state = MEI_FILE_DISCONNECT_REPLY;
800 		return ret;
801 	}
802 
803 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
804 	cl->timer_count = MEI_CONNECT_TIMEOUT;
805 
806 	return 0;
807 }
808 
809 /**
810  * mei_cl_irq_disconnect - processes close related operation from
811  *	interrupt thread context - send disconnect request
812  *
813  * @cl: client
814  * @cb: callback block.
815  * @cmpl_list: complete list.
816  *
817  * Return: 0, OK; otherwise, error.
818  */
819 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
820 			    struct mei_cl_cb *cmpl_list)
821 {
822 	struct mei_device *dev = cl->dev;
823 	u32 msg_slots;
824 	int slots;
825 	int ret;
826 
827 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
828 	slots = mei_hbuf_empty_slots(dev);
829 
830 	if (slots < msg_slots)
831 		return -EMSGSIZE;
832 
833 	ret = mei_cl_send_disconnect(cl, cb);
834 	if (ret)
835 		list_move_tail(&cb->list, &cmpl_list->list);
836 
837 	return ret;
838 }
839 
840 /**
841  * __mei_cl_disconnect - disconnect host client from the me one
842  *     internal function runtime pm has to be already acquired
843  *
844  * @cl: host client
845  *
846  * Return: 0 on success, <0 on failure.
847  */
848 static int __mei_cl_disconnect(struct mei_cl *cl)
849 {
850 	struct mei_device *dev;
851 	struct mei_cl_cb *cb;
852 	int rets;
853 
854 	dev = cl->dev;
855 
856 	cl->state = MEI_FILE_DISCONNECTING;
857 
858 	cb = mei_io_cb_init(cl, MEI_FOP_DISCONNECT, NULL);
859 	rets = cb ? 0 : -ENOMEM;
860 	if (rets)
861 		goto out;
862 
863 	cl_dbg(dev, cl, "add disconnect cb to control write list\n");
864 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
865 
866 	if (mei_hbuf_acquire(dev)) {
867 		rets = mei_cl_send_disconnect(cl, cb);
868 		if (rets) {
869 			cl_err(dev, cl, "failed to disconnect.\n");
870 			goto out;
871 		}
872 	}
873 
874 	mutex_unlock(&dev->device_lock);
875 	wait_event_timeout(cl->wait, cl->state == MEI_FILE_DISCONNECT_REPLY,
876 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
877 	mutex_lock(&dev->device_lock);
878 
879 	rets = cl->status;
880 	if (cl->state != MEI_FILE_DISCONNECT_REPLY) {
881 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
882 		rets = -ETIME;
883 	}
884 
885 out:
886 	/* we disconnect also on error */
887 	mei_cl_set_disconnected(cl);
888 	if (!rets)
889 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
890 
891 	mei_io_cb_free(cb);
892 	return rets;
893 }
894 
895 /**
896  * mei_cl_disconnect - disconnect host client from the me one
897  *
898  * @cl: host client
899  *
900  * Locking: called under "dev->device_lock" lock
901  *
902  * Return: 0 on success, <0 on failure.
903  */
904 int mei_cl_disconnect(struct mei_cl *cl)
905 {
906 	struct mei_device *dev;
907 	int rets;
908 
909 	if (WARN_ON(!cl || !cl->dev))
910 		return -ENODEV;
911 
912 	dev = cl->dev;
913 
914 	cl_dbg(dev, cl, "disconnecting");
915 
916 	if (!mei_cl_is_connected(cl))
917 		return 0;
918 
919 	if (mei_cl_is_fixed_address(cl)) {
920 		mei_cl_set_disconnected(cl);
921 		return 0;
922 	}
923 
924 	rets = pm_runtime_get(dev->dev);
925 	if (rets < 0 && rets != -EINPROGRESS) {
926 		pm_runtime_put_noidle(dev->dev);
927 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
928 		return rets;
929 	}
930 
931 	rets = __mei_cl_disconnect(cl);
932 
933 	cl_dbg(dev, cl, "rpm: autosuspend\n");
934 	pm_runtime_mark_last_busy(dev->dev);
935 	pm_runtime_put_autosuspend(dev->dev);
936 
937 	return rets;
938 }
939 
940 
941 /**
942  * mei_cl_is_other_connecting - checks if other
943  *    client with the same me client id is connecting
944  *
945  * @cl: private data of the file object
946  *
947  * Return: true if other client is connected, false - otherwise.
948  */
949 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
950 {
951 	struct mei_device *dev;
952 	struct mei_cl_cb *cb;
953 
954 	dev = cl->dev;
955 
956 	list_for_each_entry(cb, &dev->ctrl_rd_list.list, list) {
957 		if (cb->fop_type == MEI_FOP_CONNECT &&
958 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
959 			return true;
960 	}
961 
962 	return false;
963 }
964 
965 /**
966  * mei_cl_send_connect - send connect request
967  *
968  * @cl: host client
969  * @cb: callback block
970  *
971  * Return: 0, OK; otherwise, error.
972  */
973 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
974 {
975 	struct mei_device *dev;
976 	int ret;
977 
978 	dev = cl->dev;
979 
980 	ret = mei_hbm_cl_connect_req(dev, cl);
981 	cl->status = ret;
982 	if (ret) {
983 		cl->state = MEI_FILE_DISCONNECT_REPLY;
984 		return ret;
985 	}
986 
987 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
988 	cl->timer_count = MEI_CONNECT_TIMEOUT;
989 	return 0;
990 }
991 
992 /**
993  * mei_cl_irq_connect - send connect request in irq_thread context
994  *
995  * @cl: host client
996  * @cb: callback block
997  * @cmpl_list: complete list
998  *
999  * Return: 0, OK; otherwise, error.
1000  */
1001 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1002 			      struct mei_cl_cb *cmpl_list)
1003 {
1004 	struct mei_device *dev = cl->dev;
1005 	u32 msg_slots;
1006 	int slots;
1007 	int rets;
1008 
1009 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1010 	slots = mei_hbuf_empty_slots(dev);
1011 
1012 	if (mei_cl_is_other_connecting(cl))
1013 		return 0;
1014 
1015 	if (slots < msg_slots)
1016 		return -EMSGSIZE;
1017 
1018 	rets = mei_cl_send_connect(cl, cb);
1019 	if (rets)
1020 		list_move_tail(&cb->list, &cmpl_list->list);
1021 
1022 	return rets;
1023 }
1024 
1025 /**
1026  * mei_cl_connect - connect host client to the me one
1027  *
1028  * @cl: host client
1029  * @me_cl: me client
1030  * @file: pointer to file structure
1031  *
1032  * Locking: called under "dev->device_lock" lock
1033  *
1034  * Return: 0 on success, <0 on failure.
1035  */
1036 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1037 		   struct file *file)
1038 {
1039 	struct mei_device *dev;
1040 	struct mei_cl_cb *cb;
1041 	int rets;
1042 
1043 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1044 		return -ENODEV;
1045 
1046 	dev = cl->dev;
1047 
1048 	rets = mei_cl_set_connecting(cl, me_cl);
1049 	if (rets)
1050 		return rets;
1051 
1052 	if (mei_cl_is_fixed_address(cl)) {
1053 		cl->state = MEI_FILE_CONNECTED;
1054 		return 0;
1055 	}
1056 
1057 	rets = pm_runtime_get(dev->dev);
1058 	if (rets < 0 && rets != -EINPROGRESS) {
1059 		pm_runtime_put_noidle(dev->dev);
1060 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1061 		goto nortpm;
1062 	}
1063 
1064 	cb = mei_io_cb_init(cl, MEI_FOP_CONNECT, file);
1065 	rets = cb ? 0 : -ENOMEM;
1066 	if (rets)
1067 		goto out;
1068 
1069 	list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1070 
1071 	/* run hbuf acquire last so we don't have to undo */
1072 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1073 		rets = mei_cl_send_connect(cl, cb);
1074 		if (rets)
1075 			goto out;
1076 	}
1077 
1078 	mutex_unlock(&dev->device_lock);
1079 	wait_event_timeout(cl->wait,
1080 			(cl->state == MEI_FILE_CONNECTED ||
1081 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1082 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1083 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1084 	mutex_lock(&dev->device_lock);
1085 
1086 	if (!mei_cl_is_connected(cl)) {
1087 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1088 			mei_io_list_flush(&dev->ctrl_rd_list, cl);
1089 			mei_io_list_flush(&dev->ctrl_wr_list, cl);
1090 			 /* ignore disconnect return valuue;
1091 			  * in case of failure reset will be invoked
1092 			  */
1093 			__mei_cl_disconnect(cl);
1094 			rets = -EFAULT;
1095 			goto out;
1096 		}
1097 
1098 		/* timeout or something went really wrong */
1099 		if (!cl->status)
1100 			cl->status = -EFAULT;
1101 	}
1102 
1103 	rets = cl->status;
1104 out:
1105 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1106 	pm_runtime_mark_last_busy(dev->dev);
1107 	pm_runtime_put_autosuspend(dev->dev);
1108 
1109 	mei_io_cb_free(cb);
1110 
1111 nortpm:
1112 	if (!mei_cl_is_connected(cl))
1113 		mei_cl_set_disconnected(cl);
1114 
1115 	return rets;
1116 }
1117 
1118 /**
1119  * mei_cl_alloc_linked - allocate and link host client
1120  *
1121  * @dev: the device structure
1122  * @id: fixed host id or MEI_HOST_CLIENT_ID_ANY (-1) for generic one
1123  *
1124  * Return: cl on success ERR_PTR on failure
1125  */
1126 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev, int id)
1127 {
1128 	struct mei_cl *cl;
1129 	int ret;
1130 
1131 	cl = mei_cl_allocate(dev);
1132 	if (!cl) {
1133 		ret = -ENOMEM;
1134 		goto err;
1135 	}
1136 
1137 	ret = mei_cl_link(cl, id);
1138 	if (ret)
1139 		goto err;
1140 
1141 	return cl;
1142 err:
1143 	kfree(cl);
1144 	return ERR_PTR(ret);
1145 }
1146 
1147 
1148 
1149 /**
1150  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
1151  *
1152  * @cl: private data of the file object
1153  *
1154  * Return: 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
1155  */
1156 int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
1157 {
1158 	int rets;
1159 
1160 	if (WARN_ON(!cl || !cl->me_cl))
1161 		return -EINVAL;
1162 
1163 	if (cl->mei_flow_ctrl_creds > 0)
1164 		return 1;
1165 
1166 	if (mei_cl_is_fixed_address(cl)) {
1167 		rets = mei_cl_read_start(cl, mei_cl_mtu(cl), NULL);
1168 		if (rets && rets != -EBUSY)
1169 			return rets;
1170 		return 1;
1171 	}
1172 
1173 	if (mei_cl_is_single_recv_buf(cl)) {
1174 		if (cl->me_cl->mei_flow_ctrl_creds > 0)
1175 			return 1;
1176 	}
1177 	return 0;
1178 }
1179 
1180 /**
1181  * mei_cl_flow_ctrl_reduce - reduces flow_control.
1182  *
1183  * @cl: private data of the file object
1184  *
1185  * Return:
1186  *	0 on success
1187  *	-EINVAL when ctrl credits are <= 0
1188  */
1189 int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
1190 {
1191 	if (WARN_ON(!cl || !cl->me_cl))
1192 		return -EINVAL;
1193 
1194 	if (mei_cl_is_fixed_address(cl))
1195 		return 0;
1196 
1197 	if (mei_cl_is_single_recv_buf(cl)) {
1198 		if (WARN_ON(cl->me_cl->mei_flow_ctrl_creds <= 0))
1199 			return -EINVAL;
1200 		cl->me_cl->mei_flow_ctrl_creds--;
1201 	} else {
1202 		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
1203 			return -EINVAL;
1204 		cl->mei_flow_ctrl_creds--;
1205 	}
1206 	return 0;
1207 }
1208 
1209 /**
1210  *  mei_cl_notify_fop2req - convert fop to proper request
1211  *
1212  * @fop: client notification start response command
1213  *
1214  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1215  */
1216 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1217 {
1218 	if (fop == MEI_FOP_NOTIFY_START)
1219 		return MEI_HBM_NOTIFICATION_START;
1220 	else
1221 		return MEI_HBM_NOTIFICATION_STOP;
1222 }
1223 
1224 /**
1225  *  mei_cl_notify_req2fop - convert notification request top file operation type
1226  *
1227  * @req: hbm notification request type
1228  *
1229  * Return:  MEI_FOP_NOTIFY_START/STOP
1230  */
1231 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1232 {
1233 	if (req == MEI_HBM_NOTIFICATION_START)
1234 		return MEI_FOP_NOTIFY_START;
1235 	else
1236 		return MEI_FOP_NOTIFY_STOP;
1237 }
1238 
1239 /**
1240  * mei_cl_irq_notify - send notification request in irq_thread context
1241  *
1242  * @cl: client
1243  * @cb: callback block.
1244  * @cmpl_list: complete list.
1245  *
1246  * Return: 0 on such and error otherwise.
1247  */
1248 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1249 		      struct mei_cl_cb *cmpl_list)
1250 {
1251 	struct mei_device *dev = cl->dev;
1252 	u32 msg_slots;
1253 	int slots;
1254 	int ret;
1255 	bool request;
1256 
1257 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1258 	slots = mei_hbuf_empty_slots(dev);
1259 
1260 	if (slots < msg_slots)
1261 		return -EMSGSIZE;
1262 
1263 	request = mei_cl_notify_fop2req(cb->fop_type);
1264 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1265 	if (ret) {
1266 		cl->status = ret;
1267 		list_move_tail(&cb->list, &cmpl_list->list);
1268 		return ret;
1269 	}
1270 
1271 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1272 	return 0;
1273 }
1274 
1275 /**
1276  * mei_cl_notify_request - send notification stop/start request
1277  *
1278  * @cl: host client
1279  * @file: associate request with file
1280  * @request: 1 for start or 0 for stop
1281  *
1282  * Locking: called under "dev->device_lock" lock
1283  *
1284  * Return: 0 on such and error otherwise.
1285  */
1286 int mei_cl_notify_request(struct mei_cl *cl, struct file *file, u8 request)
1287 {
1288 	struct mei_device *dev;
1289 	struct mei_cl_cb *cb;
1290 	enum mei_cb_file_ops fop_type;
1291 	int rets;
1292 
1293 	if (WARN_ON(!cl || !cl->dev))
1294 		return -ENODEV;
1295 
1296 	dev = cl->dev;
1297 
1298 	if (!dev->hbm_f_ev_supported) {
1299 		cl_dbg(dev, cl, "notifications not supported\n");
1300 		return -EOPNOTSUPP;
1301 	}
1302 
1303 	rets = pm_runtime_get(dev->dev);
1304 	if (rets < 0 && rets != -EINPROGRESS) {
1305 		pm_runtime_put_noidle(dev->dev);
1306 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1307 		return rets;
1308 	}
1309 
1310 	fop_type = mei_cl_notify_req2fop(request);
1311 	cb = mei_io_cb_init(cl, fop_type, file);
1312 	if (!cb) {
1313 		rets = -ENOMEM;
1314 		goto out;
1315 	}
1316 
1317 	if (mei_hbuf_acquire(dev)) {
1318 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1319 			rets = -ENODEV;
1320 			goto out;
1321 		}
1322 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
1323 	} else {
1324 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1325 	}
1326 
1327 	mutex_unlock(&dev->device_lock);
1328 	wait_event_timeout(cl->wait, cl->notify_en == request,
1329 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1330 	mutex_lock(&dev->device_lock);
1331 
1332 	if (cl->notify_en != request) {
1333 		mei_io_list_flush(&dev->ctrl_rd_list, cl);
1334 		mei_io_list_flush(&dev->ctrl_wr_list, cl);
1335 		if (!cl->status)
1336 			cl->status = -EFAULT;
1337 	}
1338 
1339 	rets = cl->status;
1340 
1341 out:
1342 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1343 	pm_runtime_mark_last_busy(dev->dev);
1344 	pm_runtime_put_autosuspend(dev->dev);
1345 
1346 	mei_io_cb_free(cb);
1347 	return rets;
1348 }
1349 
1350 /**
1351  * mei_cl_notify - raise notification
1352  *
1353  * @cl: host client
1354  *
1355  * Locking: called under "dev->device_lock" lock
1356  */
1357 void mei_cl_notify(struct mei_cl *cl)
1358 {
1359 	struct mei_device *dev;
1360 
1361 	if (!cl || !cl->dev)
1362 		return;
1363 
1364 	dev = cl->dev;
1365 
1366 	if (!cl->notify_en)
1367 		return;
1368 
1369 	cl_dbg(dev, cl, "notify event");
1370 	cl->notify_ev = true;
1371 	wake_up_interruptible_all(&cl->ev_wait);
1372 
1373 	if (cl->ev_async)
1374 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1375 
1376 	mei_cl_bus_notify_event(cl);
1377 }
1378 
1379 /**
1380  * mei_cl_notify_get - get or wait for notification event
1381  *
1382  * @cl: host client
1383  * @block: this request is blocking
1384  * @notify_ev: true if notification event was received
1385  *
1386  * Locking: called under "dev->device_lock" lock
1387  *
1388  * Return: 0 on such and error otherwise.
1389  */
1390 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1391 {
1392 	struct mei_device *dev;
1393 	int rets;
1394 
1395 	*notify_ev = false;
1396 
1397 	if (WARN_ON(!cl || !cl->dev))
1398 		return -ENODEV;
1399 
1400 	dev = cl->dev;
1401 
1402 	if (!mei_cl_is_connected(cl))
1403 		return -ENODEV;
1404 
1405 	if (cl->notify_ev)
1406 		goto out;
1407 
1408 	if (!block)
1409 		return -EAGAIN;
1410 
1411 	mutex_unlock(&dev->device_lock);
1412 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1413 	mutex_lock(&dev->device_lock);
1414 
1415 	if (rets < 0)
1416 		return rets;
1417 
1418 out:
1419 	*notify_ev = cl->notify_ev;
1420 	cl->notify_ev = false;
1421 	return 0;
1422 }
1423 
1424 /**
1425  * mei_cl_read_start - the start read client message function.
1426  *
1427  * @cl: host client
1428  * @length: number of bytes to read
1429  * @fp: pointer to file structure
1430  *
1431  * Return: 0 on success, <0 on failure.
1432  */
1433 int mei_cl_read_start(struct mei_cl *cl, size_t length, struct file *fp)
1434 {
1435 	struct mei_device *dev;
1436 	struct mei_cl_cb *cb;
1437 	int rets;
1438 
1439 	if (WARN_ON(!cl || !cl->dev))
1440 		return -ENODEV;
1441 
1442 	dev = cl->dev;
1443 
1444 	if (!mei_cl_is_connected(cl))
1445 		return -ENODEV;
1446 
1447 	/* HW currently supports only one pending read */
1448 	if (!list_empty(&cl->rd_pending))
1449 		return -EBUSY;
1450 
1451 	if (!mei_me_cl_is_active(cl->me_cl)) {
1452 		cl_err(dev, cl, "no such me client\n");
1453 		return  -ENOTTY;
1454 	}
1455 
1456 	/* always allocate at least client max message */
1457 	length = max_t(size_t, length, mei_cl_mtu(cl));
1458 	cb = mei_cl_alloc_cb(cl, length, MEI_FOP_READ, fp);
1459 	if (!cb)
1460 		return -ENOMEM;
1461 
1462 	if (mei_cl_is_fixed_address(cl)) {
1463 		list_add_tail(&cb->list, &cl->rd_pending);
1464 		return 0;
1465 	}
1466 
1467 	rets = pm_runtime_get(dev->dev);
1468 	if (rets < 0 && rets != -EINPROGRESS) {
1469 		pm_runtime_put_noidle(dev->dev);
1470 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1471 		goto nortpm;
1472 	}
1473 
1474 	if (mei_hbuf_acquire(dev)) {
1475 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1476 		if (rets < 0)
1477 			goto out;
1478 
1479 		list_add_tail(&cb->list, &cl->rd_pending);
1480 	} else {
1481 		rets = 0;
1482 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
1483 	}
1484 
1485 out:
1486 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1487 	pm_runtime_mark_last_busy(dev->dev);
1488 	pm_runtime_put_autosuspend(dev->dev);
1489 nortpm:
1490 	if (rets)
1491 		mei_io_cb_free(cb);
1492 
1493 	return rets;
1494 }
1495 
1496 /**
1497  * mei_cl_irq_write - write a message to device
1498  *	from the interrupt thread context
1499  *
1500  * @cl: client
1501  * @cb: callback block.
1502  * @cmpl_list: complete list.
1503  *
1504  * Return: 0, OK; otherwise error.
1505  */
1506 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1507 		     struct mei_cl_cb *cmpl_list)
1508 {
1509 	struct mei_device *dev;
1510 	struct mei_msg_data *buf;
1511 	struct mei_msg_hdr mei_hdr;
1512 	size_t len;
1513 	u32 msg_slots;
1514 	int slots;
1515 	int rets;
1516 	bool first_chunk;
1517 
1518 	if (WARN_ON(!cl || !cl->dev))
1519 		return -ENODEV;
1520 
1521 	dev = cl->dev;
1522 
1523 	buf = &cb->buf;
1524 
1525 	first_chunk = cb->buf_idx == 0;
1526 
1527 	rets = first_chunk ? mei_cl_flow_ctrl_creds(cl) : 1;
1528 	if (rets < 0)
1529 		return rets;
1530 
1531 	if (rets == 0) {
1532 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1533 		return 0;
1534 	}
1535 
1536 	slots = mei_hbuf_empty_slots(dev);
1537 	len = buf->size - cb->buf_idx;
1538 	msg_slots = mei_data2slots(len);
1539 
1540 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1541 	mei_hdr.me_addr = mei_cl_me_id(cl);
1542 	mei_hdr.reserved = 0;
1543 	mei_hdr.internal = cb->internal;
1544 
1545 	if (slots >= msg_slots) {
1546 		mei_hdr.length = len;
1547 		mei_hdr.msg_complete = 1;
1548 	/* Split the message only if we can write the whole host buffer */
1549 	} else if (slots == dev->hbuf_depth) {
1550 		msg_slots = slots;
1551 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1552 		mei_hdr.length = len;
1553 		mei_hdr.msg_complete = 0;
1554 	} else {
1555 		/* wait for next time the host buffer is empty */
1556 		return 0;
1557 	}
1558 
1559 	cl_dbg(dev, cl, "buf: size = %d idx = %lu\n",
1560 			cb->buf.size, cb->buf_idx);
1561 
1562 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1563 	if (rets) {
1564 		cl->status = rets;
1565 		list_move_tail(&cb->list, &cmpl_list->list);
1566 		return rets;
1567 	}
1568 
1569 	cl->status = 0;
1570 	cl->writing_state = MEI_WRITING;
1571 	cb->buf_idx += mei_hdr.length;
1572 	cb->completed = mei_hdr.msg_complete == 1;
1573 
1574 	if (first_chunk) {
1575 		if (mei_cl_flow_ctrl_reduce(cl))
1576 			return -EIO;
1577 	}
1578 
1579 	if (mei_hdr.msg_complete)
1580 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
1581 
1582 	return 0;
1583 }
1584 
1585 /**
1586  * mei_cl_write - submit a write cb to mei device
1587  *	assumes device_lock is locked
1588  *
1589  * @cl: host client
1590  * @cb: write callback with filled data
1591  * @blocking: block until completed
1592  *
1593  * Return: number of bytes sent on success, <0 on failure.
1594  */
1595 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
1596 {
1597 	struct mei_device *dev;
1598 	struct mei_msg_data *buf;
1599 	struct mei_msg_hdr mei_hdr;
1600 	int size;
1601 	int rets;
1602 
1603 
1604 	if (WARN_ON(!cl || !cl->dev))
1605 		return -ENODEV;
1606 
1607 	if (WARN_ON(!cb))
1608 		return -EINVAL;
1609 
1610 	dev = cl->dev;
1611 
1612 	buf = &cb->buf;
1613 	size = buf->size;
1614 
1615 	cl_dbg(dev, cl, "size=%d\n", size);
1616 
1617 	rets = pm_runtime_get(dev->dev);
1618 	if (rets < 0 && rets != -EINPROGRESS) {
1619 		pm_runtime_put_noidle(dev->dev);
1620 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1621 		return rets;
1622 	}
1623 
1624 	cb->buf_idx = 0;
1625 	cl->writing_state = MEI_IDLE;
1626 
1627 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1628 	mei_hdr.me_addr = mei_cl_me_id(cl);
1629 	mei_hdr.reserved = 0;
1630 	mei_hdr.msg_complete = 0;
1631 	mei_hdr.internal = cb->internal;
1632 
1633 	rets = mei_cl_flow_ctrl_creds(cl);
1634 	if (rets < 0)
1635 		goto err;
1636 
1637 	if (rets == 0) {
1638 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1639 		rets = size;
1640 		goto out;
1641 	}
1642 	if (!mei_hbuf_acquire(dev)) {
1643 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1644 		rets = size;
1645 		goto out;
1646 	}
1647 
1648 	/* Check for a maximum length */
1649 	if (size > mei_hbuf_max_len(dev)) {
1650 		mei_hdr.length = mei_hbuf_max_len(dev);
1651 		mei_hdr.msg_complete = 0;
1652 	} else {
1653 		mei_hdr.length = size;
1654 		mei_hdr.msg_complete = 1;
1655 	}
1656 
1657 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1658 	if (rets)
1659 		goto err;
1660 
1661 	rets = mei_cl_flow_ctrl_reduce(cl);
1662 	if (rets)
1663 		goto err;
1664 
1665 	cl->writing_state = MEI_WRITING;
1666 	cb->buf_idx = mei_hdr.length;
1667 	cb->completed = mei_hdr.msg_complete == 1;
1668 
1669 out:
1670 	if (mei_hdr.msg_complete)
1671 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
1672 	else
1673 		list_add_tail(&cb->list, &dev->write_list.list);
1674 
1675 	cb = NULL;
1676 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1677 
1678 		mutex_unlock(&dev->device_lock);
1679 		rets = wait_event_interruptible(cl->tx_wait,
1680 				cl->writing_state == MEI_WRITE_COMPLETE);
1681 		mutex_lock(&dev->device_lock);
1682 		/* wait_event_interruptible returns -ERESTARTSYS */
1683 		if (rets) {
1684 			if (signal_pending(current))
1685 				rets = -EINTR;
1686 			goto err;
1687 		}
1688 	}
1689 
1690 	rets = size;
1691 err:
1692 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1693 	pm_runtime_mark_last_busy(dev->dev);
1694 	pm_runtime_put_autosuspend(dev->dev);
1695 
1696 	return rets;
1697 }
1698 
1699 
1700 /**
1701  * mei_cl_complete - processes completed operation for a client
1702  *
1703  * @cl: private data of the file object.
1704  * @cb: callback block.
1705  */
1706 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1707 {
1708 	struct mei_device *dev = cl->dev;
1709 
1710 	switch (cb->fop_type) {
1711 	case MEI_FOP_WRITE:
1712 		mei_io_cb_free(cb);
1713 		cl->writing_state = MEI_WRITE_COMPLETE;
1714 		if (waitqueue_active(&cl->tx_wait)) {
1715 			wake_up_interruptible(&cl->tx_wait);
1716 		} else {
1717 			pm_runtime_mark_last_busy(dev->dev);
1718 			pm_request_autosuspend(dev->dev);
1719 		}
1720 		break;
1721 
1722 	case MEI_FOP_READ:
1723 		list_add_tail(&cb->list, &cl->rd_completed);
1724 		if (waitqueue_active(&cl->rx_wait))
1725 			wake_up_interruptible_all(&cl->rx_wait);
1726 		else
1727 			mei_cl_bus_rx_event(cl);
1728 		break;
1729 
1730 	case MEI_FOP_CONNECT:
1731 	case MEI_FOP_DISCONNECT:
1732 	case MEI_FOP_NOTIFY_STOP:
1733 	case MEI_FOP_NOTIFY_START:
1734 		if (waitqueue_active(&cl->wait))
1735 			wake_up(&cl->wait);
1736 
1737 		break;
1738 	default:
1739 		BUG_ON(0);
1740 	}
1741 }
1742 
1743 
1744 /**
1745  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1746  *
1747  * @dev: mei device
1748  */
1749 void mei_cl_all_disconnect(struct mei_device *dev)
1750 {
1751 	struct mei_cl *cl;
1752 
1753 	list_for_each_entry(cl, &dev->file_list, link)
1754 		mei_cl_set_disconnected(cl);
1755 }
1756 
1757 
1758 /**
1759  * mei_cl_all_wakeup  - wake up all readers and writers they can be interrupted
1760  *
1761  * @dev: mei device
1762  */
1763 void mei_cl_all_wakeup(struct mei_device *dev)
1764 {
1765 	struct mei_cl *cl;
1766 
1767 	list_for_each_entry(cl, &dev->file_list, link) {
1768 		if (waitqueue_active(&cl->rx_wait)) {
1769 			cl_dbg(dev, cl, "Waking up reading client!\n");
1770 			wake_up_interruptible(&cl->rx_wait);
1771 		}
1772 		if (waitqueue_active(&cl->tx_wait)) {
1773 			cl_dbg(dev, cl, "Waking up writing client!\n");
1774 			wake_up_interruptible(&cl->tx_wait);
1775 		}
1776 
1777 		/* synchronized under device mutex */
1778 		if (waitqueue_active(&cl->ev_wait)) {
1779 			cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
1780 			wake_up_interruptible(&cl->ev_wait);
1781 		}
1782 	}
1783 }
1784 
1785 /**
1786  * mei_cl_all_write_clear - clear all pending writes
1787  *
1788  * @dev: mei device
1789  */
1790 void mei_cl_all_write_clear(struct mei_device *dev)
1791 {
1792 	mei_io_list_free(&dev->write_list, NULL);
1793 	mei_io_list_free(&dev->write_waiting_list, NULL);
1794 }
1795 
1796 
1797