xref: /openbmc/linux/drivers/misc/mei/client.c (revision dce8efa0575c8d9b5f9f9ae41437200c6d3e0bf3)
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/signal.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 static struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl,
362 					enum mei_cb_file_ops type,
363 					const struct file *fp)
364 {
365 	struct mei_cl_cb *cb;
366 
367 	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
368 	if (!cb)
369 		return NULL;
370 
371 	INIT_LIST_HEAD(&cb->list);
372 	cb->fp = fp;
373 	cb->cl = cl;
374 	cb->buf_idx = 0;
375 	cb->fop_type = type;
376 	return cb;
377 }
378 
379 /**
380  * __mei_io_list_flush_cl - removes and frees cbs belonging to cl.
381  *
382  * @head:  an instance of our list structure
383  * @cl:    host client, can be NULL for flushing the whole list
384  * @free:  whether to free the cbs
385  */
386 static void __mei_io_list_flush_cl(struct list_head *head,
387 				   const struct mei_cl *cl, bool free)
388 {
389 	struct mei_cl_cb *cb, *next;
390 
391 	/* enable removing everything if no cl is specified */
392 	list_for_each_entry_safe(cb, next, head, list) {
393 		if (!cl || mei_cl_cmp_id(cl, cb->cl)) {
394 			list_del_init(&cb->list);
395 			if (free)
396 				mei_io_cb_free(cb);
397 		}
398 	}
399 }
400 
401 /**
402  * mei_io_list_flush_cl - removes list entry belonging to cl.
403  *
404  * @head: An instance of our list structure
405  * @cl: host client
406  */
407 static inline void mei_io_list_flush_cl(struct list_head *head,
408 					const struct mei_cl *cl)
409 {
410 	__mei_io_list_flush_cl(head, cl, false);
411 }
412 
413 /**
414  * mei_io_list_free_cl - removes cb belonging to cl and free them
415  *
416  * @head: An instance of our list structure
417  * @cl: host client
418  */
419 static inline void mei_io_list_free_cl(struct list_head *head,
420 				       const struct mei_cl *cl)
421 {
422 	__mei_io_list_flush_cl(head, cl, true);
423 }
424 
425 /**
426  * mei_io_list_free_fp - free cb from a list that matches file pointer
427  *
428  * @head: io list
429  * @fp: file pointer (matching cb file object), may be NULL
430  */
431 static void mei_io_list_free_fp(struct list_head *head, const struct file *fp)
432 {
433 	struct mei_cl_cb *cb, *next;
434 
435 	list_for_each_entry_safe(cb, next, head, list)
436 		if (!fp || fp == cb->fp)
437 			mei_io_cb_free(cb);
438 }
439 
440 /**
441  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
442  *
443  * @cl: host client
444  * @length: size of the buffer
445  * @fop_type: operation type
446  * @fp: associated file pointer (might be NULL)
447  *
448  * Return: cb on success and NULL on failure
449  */
450 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
451 				  enum mei_cb_file_ops fop_type,
452 				  const struct file *fp)
453 {
454 	struct mei_cl_cb *cb;
455 
456 	cb = mei_io_cb_init(cl, fop_type, fp);
457 	if (!cb)
458 		return NULL;
459 
460 	if (length == 0)
461 		return cb;
462 
463 	cb->buf.data = kmalloc(length, GFP_KERNEL);
464 	if (!cb->buf.data) {
465 		mei_io_cb_free(cb);
466 		return NULL;
467 	}
468 	cb->buf.size = length;
469 
470 	return cb;
471 }
472 
473 /**
474  * mei_cl_enqueue_ctrl_wr_cb - a convenient wrapper for allocating
475  *     and enqueuing of the control commands cb
476  *
477  * @cl: host client
478  * @length: size of the buffer
479  * @fop_type: operation type
480  * @fp: associated file pointer (might be NULL)
481  *
482  * Return: cb on success and NULL on failure
483  * Locking: called under "dev->device_lock" lock
484  */
485 struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length,
486 					    enum mei_cb_file_ops fop_type,
487 					    const struct file *fp)
488 {
489 	struct mei_cl_cb *cb;
490 
491 	/* for RX always allocate at least client's mtu */
492 	if (length)
493 		length = max_t(size_t, length, mei_cl_mtu(cl));
494 
495 	cb = mei_cl_alloc_cb(cl, length, fop_type, fp);
496 	if (!cb)
497 		return NULL;
498 
499 	list_add_tail(&cb->list, &cl->dev->ctrl_wr_list);
500 	return cb;
501 }
502 
503 /**
504  * mei_cl_read_cb - find this cl's callback in the read list
505  *     for a specific file
506  *
507  * @cl: host client
508  * @fp: file pointer (matching cb file object), may be NULL
509  *
510  * Return: cb on success, NULL if cb is not found
511  */
512 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
513 {
514 	struct mei_cl_cb *cb;
515 
516 	list_for_each_entry(cb, &cl->rd_completed, list)
517 		if (!fp || fp == cb->fp)
518 			return cb;
519 
520 	return NULL;
521 }
522 
523 /**
524  * mei_cl_flush_queues - flushes queue lists belonging to cl.
525  *
526  * @cl: host client
527  * @fp: file pointer (matching cb file object), may be NULL
528  *
529  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
530  */
531 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
532 {
533 	struct mei_device *dev;
534 
535 	if (WARN_ON(!cl || !cl->dev))
536 		return -EINVAL;
537 
538 	dev = cl->dev;
539 
540 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
541 	mei_io_list_free_cl(&cl->dev->write_list, cl);
542 	mei_io_list_free_cl(&cl->dev->write_waiting_list, cl);
543 	mei_io_list_flush_cl(&cl->dev->ctrl_wr_list, cl);
544 	mei_io_list_flush_cl(&cl->dev->ctrl_rd_list, cl);
545 	mei_io_list_free_fp(&cl->rd_pending, fp);
546 	mei_io_list_free_fp(&cl->rd_completed, fp);
547 
548 	return 0;
549 }
550 
551 /**
552  * mei_cl_init - initializes cl.
553  *
554  * @cl: host client to be initialized
555  * @dev: mei device
556  */
557 static void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
558 {
559 	memset(cl, 0, sizeof(struct mei_cl));
560 	init_waitqueue_head(&cl->wait);
561 	init_waitqueue_head(&cl->rx_wait);
562 	init_waitqueue_head(&cl->tx_wait);
563 	init_waitqueue_head(&cl->ev_wait);
564 	INIT_LIST_HEAD(&cl->rd_completed);
565 	INIT_LIST_HEAD(&cl->rd_pending);
566 	INIT_LIST_HEAD(&cl->link);
567 	cl->writing_state = MEI_IDLE;
568 	cl->state = MEI_FILE_UNINITIALIZED;
569 	cl->dev = dev;
570 }
571 
572 /**
573  * mei_cl_allocate - allocates cl  structure and sets it up.
574  *
575  * @dev: mei device
576  * Return:  The allocated file or NULL on failure
577  */
578 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
579 {
580 	struct mei_cl *cl;
581 
582 	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
583 	if (!cl)
584 		return NULL;
585 
586 	mei_cl_init(cl, dev);
587 
588 	return cl;
589 }
590 
591 /**
592  * mei_cl_link - allocate host id in the host map
593  *
594  * @cl: host client
595  *
596  * Return: 0 on success
597  *	-EINVAL on incorrect values
598  *	-EMFILE if open count exceeded.
599  */
600 int mei_cl_link(struct mei_cl *cl)
601 {
602 	struct mei_device *dev;
603 	int id;
604 
605 	if (WARN_ON(!cl || !cl->dev))
606 		return -EINVAL;
607 
608 	dev = cl->dev;
609 
610 	id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
611 	if (id >= MEI_CLIENTS_MAX) {
612 		dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
613 		return -EMFILE;
614 	}
615 
616 	if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
617 		dev_err(dev->dev, "open_handle_count exceeded %d",
618 			MEI_MAX_OPEN_HANDLE_COUNT);
619 		return -EMFILE;
620 	}
621 
622 	dev->open_handle_count++;
623 
624 	cl->host_client_id = id;
625 	list_add_tail(&cl->link, &dev->file_list);
626 
627 	set_bit(id, dev->host_clients_map);
628 
629 	cl->state = MEI_FILE_INITIALIZING;
630 
631 	cl_dbg(dev, cl, "link cl\n");
632 	return 0;
633 }
634 
635 /**
636  * mei_cl_unlink - remove host client from the list
637  *
638  * @cl: host client
639  *
640  * Return: always 0
641  */
642 int mei_cl_unlink(struct mei_cl *cl)
643 {
644 	struct mei_device *dev;
645 
646 	/* don't shout on error exit path */
647 	if (!cl)
648 		return 0;
649 
650 	if (WARN_ON(!cl->dev))
651 		return 0;
652 
653 	dev = cl->dev;
654 
655 	cl_dbg(dev, cl, "unlink client");
656 
657 	if (dev->open_handle_count > 0)
658 		dev->open_handle_count--;
659 
660 	/* never clear the 0 bit */
661 	if (cl->host_client_id)
662 		clear_bit(cl->host_client_id, dev->host_clients_map);
663 
664 	list_del_init(&cl->link);
665 
666 	cl->state = MEI_FILE_UNINITIALIZED;
667 	cl->writing_state = MEI_IDLE;
668 
669 	WARN_ON(!list_empty(&cl->rd_completed) ||
670 		!list_empty(&cl->rd_pending) ||
671 		!list_empty(&cl->link));
672 
673 	return 0;
674 }
675 
676 void mei_host_client_init(struct mei_device *dev)
677 {
678 	dev->dev_state = MEI_DEV_ENABLED;
679 	dev->reset_count = 0;
680 
681 	schedule_work(&dev->bus_rescan_work);
682 
683 	pm_runtime_mark_last_busy(dev->dev);
684 	dev_dbg(dev->dev, "rpm: autosuspend\n");
685 	pm_request_autosuspend(dev->dev);
686 }
687 
688 /**
689  * mei_hbuf_acquire - try to acquire host buffer
690  *
691  * @dev: the device structure
692  * Return: true if host buffer was acquired
693  */
694 bool mei_hbuf_acquire(struct mei_device *dev)
695 {
696 	if (mei_pg_state(dev) == MEI_PG_ON ||
697 	    mei_pg_in_transition(dev)) {
698 		dev_dbg(dev->dev, "device is in pg\n");
699 		return false;
700 	}
701 
702 	if (!dev->hbuf_is_ready) {
703 		dev_dbg(dev->dev, "hbuf is not ready\n");
704 		return false;
705 	}
706 
707 	dev->hbuf_is_ready = false;
708 
709 	return true;
710 }
711 
712 /**
713  * mei_cl_wake_all - wake up readers, writers and event waiters so
714  *                 they can be interrupted
715  *
716  * @cl: host client
717  */
718 static void mei_cl_wake_all(struct mei_cl *cl)
719 {
720 	struct mei_device *dev = cl->dev;
721 
722 	/* synchronized under device mutex */
723 	if (waitqueue_active(&cl->rx_wait)) {
724 		cl_dbg(dev, cl, "Waking up reading client!\n");
725 		wake_up_interruptible(&cl->rx_wait);
726 	}
727 	/* synchronized under device mutex */
728 	if (waitqueue_active(&cl->tx_wait)) {
729 		cl_dbg(dev, cl, "Waking up writing client!\n");
730 		wake_up_interruptible(&cl->tx_wait);
731 	}
732 	/* synchronized under device mutex */
733 	if (waitqueue_active(&cl->ev_wait)) {
734 		cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
735 		wake_up_interruptible(&cl->ev_wait);
736 	}
737 	/* synchronized under device mutex */
738 	if (waitqueue_active(&cl->wait)) {
739 		cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
740 		wake_up(&cl->wait);
741 	}
742 }
743 
744 /**
745  * mei_cl_set_disconnected - set disconnected state and clear
746  *   associated states and resources
747  *
748  * @cl: host client
749  */
750 static void mei_cl_set_disconnected(struct mei_cl *cl)
751 {
752 	struct mei_device *dev = cl->dev;
753 
754 	if (cl->state == MEI_FILE_DISCONNECTED ||
755 	    cl->state <= MEI_FILE_INITIALIZING)
756 		return;
757 
758 	cl->state = MEI_FILE_DISCONNECTED;
759 	mei_io_list_free_cl(&dev->write_list, cl);
760 	mei_io_list_free_cl(&dev->write_waiting_list, cl);
761 	mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
762 	mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
763 	mei_cl_wake_all(cl);
764 	cl->rx_flow_ctrl_creds = 0;
765 	cl->tx_flow_ctrl_creds = 0;
766 	cl->timer_count = 0;
767 
768 	mei_cl_bus_module_put(cl);
769 
770 	if (!cl->me_cl)
771 		return;
772 
773 	if (!WARN_ON(cl->me_cl->connect_count == 0))
774 		cl->me_cl->connect_count--;
775 
776 	if (cl->me_cl->connect_count == 0)
777 		cl->me_cl->tx_flow_ctrl_creds = 0;
778 
779 	mei_me_cl_put(cl->me_cl);
780 	cl->me_cl = NULL;
781 }
782 
783 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
784 {
785 	if (!mei_me_cl_get(me_cl))
786 		return -ENOENT;
787 
788 	/* only one connection is allowed for fixed address clients */
789 	if (me_cl->props.fixed_address) {
790 		if (me_cl->connect_count) {
791 			mei_me_cl_put(me_cl);
792 			return -EBUSY;
793 		}
794 	}
795 
796 	cl->me_cl = me_cl;
797 	cl->state = MEI_FILE_CONNECTING;
798 	cl->me_cl->connect_count++;
799 
800 	return 0;
801 }
802 
803 /*
804  * mei_cl_send_disconnect - send disconnect request
805  *
806  * @cl: host client
807  * @cb: callback block
808  *
809  * Return: 0, OK; otherwise, error.
810  */
811 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
812 {
813 	struct mei_device *dev;
814 	int ret;
815 
816 	dev = cl->dev;
817 
818 	ret = mei_hbm_cl_disconnect_req(dev, cl);
819 	cl->status = ret;
820 	if (ret) {
821 		cl->state = MEI_FILE_DISCONNECT_REPLY;
822 		return ret;
823 	}
824 
825 	list_move_tail(&cb->list, &dev->ctrl_rd_list);
826 	cl->timer_count = MEI_CONNECT_TIMEOUT;
827 	mei_schedule_stall_timer(dev);
828 
829 	return 0;
830 }
831 
832 /**
833  * mei_cl_irq_disconnect - processes close related operation from
834  *	interrupt thread context - send disconnect request
835  *
836  * @cl: client
837  * @cb: callback block.
838  * @cmpl_list: complete list.
839  *
840  * Return: 0, OK; otherwise, error.
841  */
842 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
843 			  struct list_head *cmpl_list)
844 {
845 	struct mei_device *dev = cl->dev;
846 	u32 msg_slots;
847 	int slots;
848 	int ret;
849 
850 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
851 	slots = mei_hbuf_empty_slots(dev);
852 
853 	if (slots < msg_slots)
854 		return -EMSGSIZE;
855 
856 	ret = mei_cl_send_disconnect(cl, cb);
857 	if (ret)
858 		list_move_tail(&cb->list, cmpl_list);
859 
860 	return ret;
861 }
862 
863 /**
864  * __mei_cl_disconnect - disconnect host client from the me one
865  *     internal function runtime pm has to be already acquired
866  *
867  * @cl: host client
868  *
869  * Return: 0 on success, <0 on failure.
870  */
871 static int __mei_cl_disconnect(struct mei_cl *cl)
872 {
873 	struct mei_device *dev;
874 	struct mei_cl_cb *cb;
875 	int rets;
876 
877 	dev = cl->dev;
878 
879 	cl->state = MEI_FILE_DISCONNECTING;
880 
881 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT, NULL);
882 	if (!cb) {
883 		rets = -ENOMEM;
884 		goto out;
885 	}
886 
887 	if (mei_hbuf_acquire(dev)) {
888 		rets = mei_cl_send_disconnect(cl, cb);
889 		if (rets) {
890 			cl_err(dev, cl, "failed to disconnect.\n");
891 			goto out;
892 		}
893 	}
894 
895 	mutex_unlock(&dev->device_lock);
896 	wait_event_timeout(cl->wait,
897 			   cl->state == MEI_FILE_DISCONNECT_REPLY ||
898 			   cl->state == MEI_FILE_DISCONNECTED,
899 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
900 	mutex_lock(&dev->device_lock);
901 
902 	rets = cl->status;
903 	if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
904 	    cl->state != MEI_FILE_DISCONNECTED) {
905 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
906 		rets = -ETIME;
907 	}
908 
909 out:
910 	/* we disconnect also on error */
911 	mei_cl_set_disconnected(cl);
912 	if (!rets)
913 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
914 
915 	mei_io_cb_free(cb);
916 	return rets;
917 }
918 
919 /**
920  * mei_cl_disconnect - disconnect host client from the me one
921  *
922  * @cl: host client
923  *
924  * Locking: called under "dev->device_lock" lock
925  *
926  * Return: 0 on success, <0 on failure.
927  */
928 int mei_cl_disconnect(struct mei_cl *cl)
929 {
930 	struct mei_device *dev;
931 	int rets;
932 
933 	if (WARN_ON(!cl || !cl->dev))
934 		return -ENODEV;
935 
936 	dev = cl->dev;
937 
938 	cl_dbg(dev, cl, "disconnecting");
939 
940 	if (!mei_cl_is_connected(cl))
941 		return 0;
942 
943 	if (mei_cl_is_fixed_address(cl)) {
944 		mei_cl_set_disconnected(cl);
945 		return 0;
946 	}
947 
948 	if (dev->dev_state == MEI_DEV_POWER_DOWN) {
949 		cl_dbg(dev, cl, "Device is powering down, don't bother with disconnection\n");
950 		mei_cl_set_disconnected(cl);
951 		return 0;
952 	}
953 
954 	rets = pm_runtime_get(dev->dev);
955 	if (rets < 0 && rets != -EINPROGRESS) {
956 		pm_runtime_put_noidle(dev->dev);
957 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
958 		return rets;
959 	}
960 
961 	rets = __mei_cl_disconnect(cl);
962 
963 	cl_dbg(dev, cl, "rpm: autosuspend\n");
964 	pm_runtime_mark_last_busy(dev->dev);
965 	pm_runtime_put_autosuspend(dev->dev);
966 
967 	return rets;
968 }
969 
970 
971 /**
972  * mei_cl_is_other_connecting - checks if other
973  *    client with the same me client id is connecting
974  *
975  * @cl: private data of the file object
976  *
977  * Return: true if other client is connected, false - otherwise.
978  */
979 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
980 {
981 	struct mei_device *dev;
982 	struct mei_cl_cb *cb;
983 
984 	dev = cl->dev;
985 
986 	list_for_each_entry(cb, &dev->ctrl_rd_list, list) {
987 		if (cb->fop_type == MEI_FOP_CONNECT &&
988 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
989 			return true;
990 	}
991 
992 	return false;
993 }
994 
995 /**
996  * mei_cl_send_connect - send connect request
997  *
998  * @cl: host client
999  * @cb: callback block
1000  *
1001  * Return: 0, OK; otherwise, error.
1002  */
1003 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
1004 {
1005 	struct mei_device *dev;
1006 	int ret;
1007 
1008 	dev = cl->dev;
1009 
1010 	ret = mei_hbm_cl_connect_req(dev, cl);
1011 	cl->status = ret;
1012 	if (ret) {
1013 		cl->state = MEI_FILE_DISCONNECT_REPLY;
1014 		return ret;
1015 	}
1016 
1017 	list_move_tail(&cb->list, &dev->ctrl_rd_list);
1018 	cl->timer_count = MEI_CONNECT_TIMEOUT;
1019 	mei_schedule_stall_timer(dev);
1020 	return 0;
1021 }
1022 
1023 /**
1024  * mei_cl_irq_connect - send connect request in irq_thread context
1025  *
1026  * @cl: host client
1027  * @cb: callback block
1028  * @cmpl_list: complete list
1029  *
1030  * Return: 0, OK; otherwise, error.
1031  */
1032 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1033 		       struct list_head *cmpl_list)
1034 {
1035 	struct mei_device *dev = cl->dev;
1036 	u32 msg_slots;
1037 	int slots;
1038 	int rets;
1039 
1040 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1041 	slots = mei_hbuf_empty_slots(dev);
1042 
1043 	if (mei_cl_is_other_connecting(cl))
1044 		return 0;
1045 
1046 	if (slots < msg_slots)
1047 		return -EMSGSIZE;
1048 
1049 	rets = mei_cl_send_connect(cl, cb);
1050 	if (rets)
1051 		list_move_tail(&cb->list, cmpl_list);
1052 
1053 	return rets;
1054 }
1055 
1056 /**
1057  * mei_cl_connect - connect host client to the me one
1058  *
1059  * @cl: host client
1060  * @me_cl: me client
1061  * @fp: pointer to file structure
1062  *
1063  * Locking: called under "dev->device_lock" lock
1064  *
1065  * Return: 0 on success, <0 on failure.
1066  */
1067 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1068 		   const struct file *fp)
1069 {
1070 	struct mei_device *dev;
1071 	struct mei_cl_cb *cb;
1072 	int rets;
1073 
1074 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1075 		return -ENODEV;
1076 
1077 	dev = cl->dev;
1078 
1079 	if (!mei_cl_bus_module_get(cl))
1080 		return -ENODEV;
1081 
1082 	rets = mei_cl_set_connecting(cl, me_cl);
1083 	if (rets)
1084 		goto nortpm;
1085 
1086 	if (mei_cl_is_fixed_address(cl)) {
1087 		cl->state = MEI_FILE_CONNECTED;
1088 		rets = 0;
1089 		goto nortpm;
1090 	}
1091 
1092 	rets = pm_runtime_get(dev->dev);
1093 	if (rets < 0 && rets != -EINPROGRESS) {
1094 		pm_runtime_put_noidle(dev->dev);
1095 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1096 		goto nortpm;
1097 	}
1098 
1099 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_CONNECT, fp);
1100 	if (!cb) {
1101 		rets = -ENOMEM;
1102 		goto out;
1103 	}
1104 
1105 	/* run hbuf acquire last so we don't have to undo */
1106 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1107 		rets = mei_cl_send_connect(cl, cb);
1108 		if (rets)
1109 			goto out;
1110 	}
1111 
1112 	mutex_unlock(&dev->device_lock);
1113 	wait_event_timeout(cl->wait,
1114 			(cl->state == MEI_FILE_CONNECTED ||
1115 			 cl->state == MEI_FILE_DISCONNECTED ||
1116 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1117 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1118 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1119 	mutex_lock(&dev->device_lock);
1120 
1121 	if (!mei_cl_is_connected(cl)) {
1122 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1123 			mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
1124 			mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
1125 			 /* ignore disconnect return valuue;
1126 			  * in case of failure reset will be invoked
1127 			  */
1128 			__mei_cl_disconnect(cl);
1129 			rets = -EFAULT;
1130 			goto out;
1131 		}
1132 
1133 		/* timeout or something went really wrong */
1134 		if (!cl->status)
1135 			cl->status = -EFAULT;
1136 	}
1137 
1138 	rets = cl->status;
1139 out:
1140 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1141 	pm_runtime_mark_last_busy(dev->dev);
1142 	pm_runtime_put_autosuspend(dev->dev);
1143 
1144 	mei_io_cb_free(cb);
1145 
1146 nortpm:
1147 	if (!mei_cl_is_connected(cl))
1148 		mei_cl_set_disconnected(cl);
1149 
1150 	return rets;
1151 }
1152 
1153 /**
1154  * mei_cl_alloc_linked - allocate and link host client
1155  *
1156  * @dev: the device structure
1157  *
1158  * Return: cl on success ERR_PTR on failure
1159  */
1160 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1161 {
1162 	struct mei_cl *cl;
1163 	int ret;
1164 
1165 	cl = mei_cl_allocate(dev);
1166 	if (!cl) {
1167 		ret = -ENOMEM;
1168 		goto err;
1169 	}
1170 
1171 	ret = mei_cl_link(cl);
1172 	if (ret)
1173 		goto err;
1174 
1175 	return cl;
1176 err:
1177 	kfree(cl);
1178 	return ERR_PTR(ret);
1179 }
1180 
1181 /**
1182  * mei_cl_tx_flow_ctrl_creds - checks flow_control credits for cl.
1183  *
1184  * @cl: host client
1185  *
1186  * Return: 1 if tx_flow_ctrl_creds >0, 0 - otherwise.
1187  */
1188 static int mei_cl_tx_flow_ctrl_creds(struct mei_cl *cl)
1189 {
1190 	if (WARN_ON(!cl || !cl->me_cl))
1191 		return -EINVAL;
1192 
1193 	if (cl->tx_flow_ctrl_creds > 0)
1194 		return 1;
1195 
1196 	if (mei_cl_is_fixed_address(cl))
1197 		return 1;
1198 
1199 	if (mei_cl_is_single_recv_buf(cl)) {
1200 		if (cl->me_cl->tx_flow_ctrl_creds > 0)
1201 			return 1;
1202 	}
1203 	return 0;
1204 }
1205 
1206 /**
1207  * mei_cl_tx_flow_ctrl_creds_reduce - reduces transmit flow control credits
1208  *   for a client
1209  *
1210  * @cl: host client
1211  *
1212  * Return:
1213  *	0 on success
1214  *	-EINVAL when ctrl credits are <= 0
1215  */
1216 static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
1217 {
1218 	if (WARN_ON(!cl || !cl->me_cl))
1219 		return -EINVAL;
1220 
1221 	if (mei_cl_is_fixed_address(cl))
1222 		return 0;
1223 
1224 	if (mei_cl_is_single_recv_buf(cl)) {
1225 		if (WARN_ON(cl->me_cl->tx_flow_ctrl_creds <= 0))
1226 			return -EINVAL;
1227 		cl->me_cl->tx_flow_ctrl_creds--;
1228 	} else {
1229 		if (WARN_ON(cl->tx_flow_ctrl_creds <= 0))
1230 			return -EINVAL;
1231 		cl->tx_flow_ctrl_creds--;
1232 	}
1233 	return 0;
1234 }
1235 
1236 /**
1237  *  mei_cl_notify_fop2req - convert fop to proper request
1238  *
1239  * @fop: client notification start response command
1240  *
1241  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1242  */
1243 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1244 {
1245 	if (fop == MEI_FOP_NOTIFY_START)
1246 		return MEI_HBM_NOTIFICATION_START;
1247 	else
1248 		return MEI_HBM_NOTIFICATION_STOP;
1249 }
1250 
1251 /**
1252  *  mei_cl_notify_req2fop - convert notification request top file operation type
1253  *
1254  * @req: hbm notification request type
1255  *
1256  * Return:  MEI_FOP_NOTIFY_START/STOP
1257  */
1258 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1259 {
1260 	if (req == MEI_HBM_NOTIFICATION_START)
1261 		return MEI_FOP_NOTIFY_START;
1262 	else
1263 		return MEI_FOP_NOTIFY_STOP;
1264 }
1265 
1266 /**
1267  * mei_cl_irq_notify - send notification request in irq_thread context
1268  *
1269  * @cl: client
1270  * @cb: callback block.
1271  * @cmpl_list: complete list.
1272  *
1273  * Return: 0 on such and error otherwise.
1274  */
1275 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1276 		      struct list_head *cmpl_list)
1277 {
1278 	struct mei_device *dev = cl->dev;
1279 	u32 msg_slots;
1280 	int slots;
1281 	int ret;
1282 	bool request;
1283 
1284 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1285 	slots = mei_hbuf_empty_slots(dev);
1286 
1287 	if (slots < msg_slots)
1288 		return -EMSGSIZE;
1289 
1290 	request = mei_cl_notify_fop2req(cb->fop_type);
1291 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1292 	if (ret) {
1293 		cl->status = ret;
1294 		list_move_tail(&cb->list, cmpl_list);
1295 		return ret;
1296 	}
1297 
1298 	list_move_tail(&cb->list, &dev->ctrl_rd_list);
1299 	return 0;
1300 }
1301 
1302 /**
1303  * mei_cl_notify_request - send notification stop/start request
1304  *
1305  * @cl: host client
1306  * @fp: associate request with file
1307  * @request: 1 for start or 0 for stop
1308  *
1309  * Locking: called under "dev->device_lock" lock
1310  *
1311  * Return: 0 on such and error otherwise.
1312  */
1313 int mei_cl_notify_request(struct mei_cl *cl,
1314 			  const struct file *fp, u8 request)
1315 {
1316 	struct mei_device *dev;
1317 	struct mei_cl_cb *cb;
1318 	enum mei_cb_file_ops fop_type;
1319 	int rets;
1320 
1321 	if (WARN_ON(!cl || !cl->dev))
1322 		return -ENODEV;
1323 
1324 	dev = cl->dev;
1325 
1326 	if (!dev->hbm_f_ev_supported) {
1327 		cl_dbg(dev, cl, "notifications not supported\n");
1328 		return -EOPNOTSUPP;
1329 	}
1330 
1331 	if (!mei_cl_is_connected(cl))
1332 		return -ENODEV;
1333 
1334 	rets = pm_runtime_get(dev->dev);
1335 	if (rets < 0 && rets != -EINPROGRESS) {
1336 		pm_runtime_put_noidle(dev->dev);
1337 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1338 		return rets;
1339 	}
1340 
1341 	fop_type = mei_cl_notify_req2fop(request);
1342 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1343 	if (!cb) {
1344 		rets = -ENOMEM;
1345 		goto out;
1346 	}
1347 
1348 	if (mei_hbuf_acquire(dev)) {
1349 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1350 			rets = -ENODEV;
1351 			goto out;
1352 		}
1353 		list_move_tail(&cb->list, &dev->ctrl_rd_list);
1354 	}
1355 
1356 	mutex_unlock(&dev->device_lock);
1357 	wait_event_timeout(cl->wait,
1358 			   cl->notify_en == request || !mei_cl_is_connected(cl),
1359 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1360 	mutex_lock(&dev->device_lock);
1361 
1362 	if (cl->notify_en != request && !cl->status)
1363 		cl->status = -EFAULT;
1364 
1365 	rets = cl->status;
1366 
1367 out:
1368 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1369 	pm_runtime_mark_last_busy(dev->dev);
1370 	pm_runtime_put_autosuspend(dev->dev);
1371 
1372 	mei_io_cb_free(cb);
1373 	return rets;
1374 }
1375 
1376 /**
1377  * mei_cl_notify - raise notification
1378  *
1379  * @cl: host client
1380  *
1381  * Locking: called under "dev->device_lock" lock
1382  */
1383 void mei_cl_notify(struct mei_cl *cl)
1384 {
1385 	struct mei_device *dev;
1386 
1387 	if (!cl || !cl->dev)
1388 		return;
1389 
1390 	dev = cl->dev;
1391 
1392 	if (!cl->notify_en)
1393 		return;
1394 
1395 	cl_dbg(dev, cl, "notify event");
1396 	cl->notify_ev = true;
1397 	if (!mei_cl_bus_notify_event(cl))
1398 		wake_up_interruptible(&cl->ev_wait);
1399 
1400 	if (cl->ev_async)
1401 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1402 
1403 }
1404 
1405 /**
1406  * mei_cl_notify_get - get or wait for notification event
1407  *
1408  * @cl: host client
1409  * @block: this request is blocking
1410  * @notify_ev: true if notification event was received
1411  *
1412  * Locking: called under "dev->device_lock" lock
1413  *
1414  * Return: 0 on such and error otherwise.
1415  */
1416 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1417 {
1418 	struct mei_device *dev;
1419 	int rets;
1420 
1421 	*notify_ev = false;
1422 
1423 	if (WARN_ON(!cl || !cl->dev))
1424 		return -ENODEV;
1425 
1426 	dev = cl->dev;
1427 
1428 	if (!dev->hbm_f_ev_supported) {
1429 		cl_dbg(dev, cl, "notifications not supported\n");
1430 		return -EOPNOTSUPP;
1431 	}
1432 
1433 	if (!mei_cl_is_connected(cl))
1434 		return -ENODEV;
1435 
1436 	if (cl->notify_ev)
1437 		goto out;
1438 
1439 	if (!block)
1440 		return -EAGAIN;
1441 
1442 	mutex_unlock(&dev->device_lock);
1443 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1444 	mutex_lock(&dev->device_lock);
1445 
1446 	if (rets < 0)
1447 		return rets;
1448 
1449 out:
1450 	*notify_ev = cl->notify_ev;
1451 	cl->notify_ev = false;
1452 	return 0;
1453 }
1454 
1455 /**
1456  * mei_cl_read_start - the start read client message function.
1457  *
1458  * @cl: host client
1459  * @length: number of bytes to read
1460  * @fp: pointer to file structure
1461  *
1462  * Return: 0 on success, <0 on failure.
1463  */
1464 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1465 {
1466 	struct mei_device *dev;
1467 	struct mei_cl_cb *cb;
1468 	int rets;
1469 
1470 	if (WARN_ON(!cl || !cl->dev))
1471 		return -ENODEV;
1472 
1473 	dev = cl->dev;
1474 
1475 	if (!mei_cl_is_connected(cl))
1476 		return -ENODEV;
1477 
1478 	if (!mei_me_cl_is_active(cl->me_cl)) {
1479 		cl_err(dev, cl, "no such me client\n");
1480 		return  -ENOTTY;
1481 	}
1482 
1483 	if (mei_cl_is_fixed_address(cl))
1484 		return 0;
1485 
1486 	/* HW currently supports only one pending read */
1487 	if (cl->rx_flow_ctrl_creds)
1488 		return -EBUSY;
1489 
1490 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1491 	if (!cb)
1492 		return -ENOMEM;
1493 
1494 	rets = pm_runtime_get(dev->dev);
1495 	if (rets < 0 && rets != -EINPROGRESS) {
1496 		pm_runtime_put_noidle(dev->dev);
1497 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1498 		goto nortpm;
1499 	}
1500 
1501 	rets = 0;
1502 	if (mei_hbuf_acquire(dev)) {
1503 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1504 		if (rets < 0)
1505 			goto out;
1506 
1507 		list_move_tail(&cb->list, &cl->rd_pending);
1508 	}
1509 	cl->rx_flow_ctrl_creds++;
1510 
1511 out:
1512 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1513 	pm_runtime_mark_last_busy(dev->dev);
1514 	pm_runtime_put_autosuspend(dev->dev);
1515 nortpm:
1516 	if (rets)
1517 		mei_io_cb_free(cb);
1518 
1519 	return rets;
1520 }
1521 
1522 /**
1523  * mei_cl_irq_write - write a message to device
1524  *	from the interrupt thread context
1525  *
1526  * @cl: client
1527  * @cb: callback block.
1528  * @cmpl_list: complete list.
1529  *
1530  * Return: 0, OK; otherwise error.
1531  */
1532 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1533 		     struct list_head *cmpl_list)
1534 {
1535 	struct mei_device *dev;
1536 	struct mei_msg_data *buf;
1537 	struct mei_msg_hdr mei_hdr;
1538 	size_t len;
1539 	u32 msg_slots;
1540 	int slots;
1541 	int rets;
1542 	bool first_chunk;
1543 
1544 	if (WARN_ON(!cl || !cl->dev))
1545 		return -ENODEV;
1546 
1547 	dev = cl->dev;
1548 
1549 	buf = &cb->buf;
1550 
1551 	first_chunk = cb->buf_idx == 0;
1552 
1553 	rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1554 	if (rets < 0)
1555 		goto err;
1556 
1557 	if (rets == 0) {
1558 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1559 		return 0;
1560 	}
1561 
1562 	slots = mei_hbuf_empty_slots(dev);
1563 	len = buf->size - cb->buf_idx;
1564 	msg_slots = mei_data2slots(len);
1565 
1566 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1567 	mei_hdr.me_addr = mei_cl_me_id(cl);
1568 	mei_hdr.reserved = 0;
1569 	mei_hdr.internal = cb->internal;
1570 
1571 	if (slots >= msg_slots) {
1572 		mei_hdr.length = len;
1573 		mei_hdr.msg_complete = 1;
1574 	/* Split the message only if we can write the whole host buffer */
1575 	} else if (slots == dev->hbuf_depth) {
1576 		msg_slots = slots;
1577 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1578 		mei_hdr.length = len;
1579 		mei_hdr.msg_complete = 0;
1580 	} else {
1581 		/* wait for next time the host buffer is empty */
1582 		return 0;
1583 	}
1584 
1585 	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1586 			cb->buf.size, cb->buf_idx);
1587 
1588 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1589 	if (rets)
1590 		goto err;
1591 
1592 	cl->status = 0;
1593 	cl->writing_state = MEI_WRITING;
1594 	cb->buf_idx += mei_hdr.length;
1595 	cb->completed = mei_hdr.msg_complete == 1;
1596 
1597 	if (first_chunk) {
1598 		if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
1599 			rets = -EIO;
1600 			goto err;
1601 		}
1602 	}
1603 
1604 	if (mei_hdr.msg_complete)
1605 		list_move_tail(&cb->list, &dev->write_waiting_list);
1606 
1607 	return 0;
1608 
1609 err:
1610 	cl->status = rets;
1611 	list_move_tail(&cb->list, cmpl_list);
1612 	return rets;
1613 }
1614 
1615 /**
1616  * mei_cl_write - submit a write cb to mei device
1617  *	assumes device_lock is locked
1618  *
1619  * @cl: host client
1620  * @cb: write callback with filled data
1621  *
1622  * Return: number of bytes sent on success, <0 on failure.
1623  */
1624 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
1625 {
1626 	struct mei_device *dev;
1627 	struct mei_msg_data *buf;
1628 	struct mei_msg_hdr mei_hdr;
1629 	int size;
1630 	int rets;
1631 	bool blocking;
1632 
1633 	if (WARN_ON(!cl || !cl->dev))
1634 		return -ENODEV;
1635 
1636 	if (WARN_ON(!cb))
1637 		return -EINVAL;
1638 
1639 	dev = cl->dev;
1640 
1641 	buf = &cb->buf;
1642 	size = buf->size;
1643 	blocking = cb->blocking;
1644 
1645 	cl_dbg(dev, cl, "size=%d\n", size);
1646 
1647 	rets = pm_runtime_get(dev->dev);
1648 	if (rets < 0 && rets != -EINPROGRESS) {
1649 		pm_runtime_put_noidle(dev->dev);
1650 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1651 		goto free;
1652 	}
1653 
1654 	cb->buf_idx = 0;
1655 	cl->writing_state = MEI_IDLE;
1656 
1657 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1658 	mei_hdr.me_addr = mei_cl_me_id(cl);
1659 	mei_hdr.reserved = 0;
1660 	mei_hdr.msg_complete = 0;
1661 	mei_hdr.internal = cb->internal;
1662 
1663 	rets = mei_cl_tx_flow_ctrl_creds(cl);
1664 	if (rets < 0)
1665 		goto err;
1666 
1667 	if (rets == 0) {
1668 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1669 		rets = size;
1670 		goto out;
1671 	}
1672 	if (!mei_hbuf_acquire(dev)) {
1673 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1674 		rets = size;
1675 		goto out;
1676 	}
1677 
1678 	/* Check for a maximum length */
1679 	if (size > mei_hbuf_max_len(dev)) {
1680 		mei_hdr.length = mei_hbuf_max_len(dev);
1681 		mei_hdr.msg_complete = 0;
1682 	} else {
1683 		mei_hdr.length = size;
1684 		mei_hdr.msg_complete = 1;
1685 	}
1686 
1687 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1688 	if (rets)
1689 		goto err;
1690 
1691 	rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1692 	if (rets)
1693 		goto err;
1694 
1695 	cl->writing_state = MEI_WRITING;
1696 	cb->buf_idx = mei_hdr.length;
1697 	cb->completed = mei_hdr.msg_complete == 1;
1698 
1699 out:
1700 	if (mei_hdr.msg_complete)
1701 		list_add_tail(&cb->list, &dev->write_waiting_list);
1702 	else
1703 		list_add_tail(&cb->list, &dev->write_list);
1704 
1705 	cb = NULL;
1706 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1707 
1708 		mutex_unlock(&dev->device_lock);
1709 		rets = wait_event_interruptible(cl->tx_wait,
1710 				cl->writing_state == MEI_WRITE_COMPLETE ||
1711 				(!mei_cl_is_connected(cl)));
1712 		mutex_lock(&dev->device_lock);
1713 		/* wait_event_interruptible returns -ERESTARTSYS */
1714 		if (rets) {
1715 			if (signal_pending(current))
1716 				rets = -EINTR;
1717 			goto err;
1718 		}
1719 		if (cl->writing_state != MEI_WRITE_COMPLETE) {
1720 			rets = -EFAULT;
1721 			goto err;
1722 		}
1723 	}
1724 
1725 	rets = size;
1726 err:
1727 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1728 	pm_runtime_mark_last_busy(dev->dev);
1729 	pm_runtime_put_autosuspend(dev->dev);
1730 free:
1731 	mei_io_cb_free(cb);
1732 
1733 	return rets;
1734 }
1735 
1736 
1737 /**
1738  * mei_cl_complete - processes completed operation for a client
1739  *
1740  * @cl: private data of the file object.
1741  * @cb: callback block.
1742  */
1743 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1744 {
1745 	struct mei_device *dev = cl->dev;
1746 
1747 	switch (cb->fop_type) {
1748 	case MEI_FOP_WRITE:
1749 		mei_io_cb_free(cb);
1750 		cl->writing_state = MEI_WRITE_COMPLETE;
1751 		if (waitqueue_active(&cl->tx_wait)) {
1752 			wake_up_interruptible(&cl->tx_wait);
1753 		} else {
1754 			pm_runtime_mark_last_busy(dev->dev);
1755 			pm_request_autosuspend(dev->dev);
1756 		}
1757 		break;
1758 
1759 	case MEI_FOP_READ:
1760 		list_add_tail(&cb->list, &cl->rd_completed);
1761 		if (!mei_cl_is_fixed_address(cl) &&
1762 		    !WARN_ON(!cl->rx_flow_ctrl_creds))
1763 			cl->rx_flow_ctrl_creds--;
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