xref: /openbmc/linux/drivers/misc/mei/client.c (revision 8cb5d748)
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 	rets = pm_runtime_get(dev->dev);
949 	if (rets < 0 && rets != -EINPROGRESS) {
950 		pm_runtime_put_noidle(dev->dev);
951 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
952 		return rets;
953 	}
954 
955 	rets = __mei_cl_disconnect(cl);
956 
957 	cl_dbg(dev, cl, "rpm: autosuspend\n");
958 	pm_runtime_mark_last_busy(dev->dev);
959 	pm_runtime_put_autosuspend(dev->dev);
960 
961 	return rets;
962 }
963 
964 
965 /**
966  * mei_cl_is_other_connecting - checks if other
967  *    client with the same me client id is connecting
968  *
969  * @cl: private data of the file object
970  *
971  * Return: true if other client is connected, false - otherwise.
972  */
973 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
974 {
975 	struct mei_device *dev;
976 	struct mei_cl_cb *cb;
977 
978 	dev = cl->dev;
979 
980 	list_for_each_entry(cb, &dev->ctrl_rd_list, list) {
981 		if (cb->fop_type == MEI_FOP_CONNECT &&
982 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
983 			return true;
984 	}
985 
986 	return false;
987 }
988 
989 /**
990  * mei_cl_send_connect - send connect request
991  *
992  * @cl: host client
993  * @cb: callback block
994  *
995  * Return: 0, OK; otherwise, error.
996  */
997 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
998 {
999 	struct mei_device *dev;
1000 	int ret;
1001 
1002 	dev = cl->dev;
1003 
1004 	ret = mei_hbm_cl_connect_req(dev, cl);
1005 	cl->status = ret;
1006 	if (ret) {
1007 		cl->state = MEI_FILE_DISCONNECT_REPLY;
1008 		return ret;
1009 	}
1010 
1011 	list_move_tail(&cb->list, &dev->ctrl_rd_list);
1012 	cl->timer_count = MEI_CONNECT_TIMEOUT;
1013 	mei_schedule_stall_timer(dev);
1014 	return 0;
1015 }
1016 
1017 /**
1018  * mei_cl_irq_connect - send connect request in irq_thread context
1019  *
1020  * @cl: host client
1021  * @cb: callback block
1022  * @cmpl_list: complete list
1023  *
1024  * Return: 0, OK; otherwise, error.
1025  */
1026 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1027 		       struct list_head *cmpl_list)
1028 {
1029 	struct mei_device *dev = cl->dev;
1030 	u32 msg_slots;
1031 	int slots;
1032 	int rets;
1033 
1034 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1035 	slots = mei_hbuf_empty_slots(dev);
1036 
1037 	if (mei_cl_is_other_connecting(cl))
1038 		return 0;
1039 
1040 	if (slots < msg_slots)
1041 		return -EMSGSIZE;
1042 
1043 	rets = mei_cl_send_connect(cl, cb);
1044 	if (rets)
1045 		list_move_tail(&cb->list, cmpl_list);
1046 
1047 	return rets;
1048 }
1049 
1050 /**
1051  * mei_cl_connect - connect host client to the me one
1052  *
1053  * @cl: host client
1054  * @me_cl: me client
1055  * @fp: pointer to file structure
1056  *
1057  * Locking: called under "dev->device_lock" lock
1058  *
1059  * Return: 0 on success, <0 on failure.
1060  */
1061 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1062 		   const struct file *fp)
1063 {
1064 	struct mei_device *dev;
1065 	struct mei_cl_cb *cb;
1066 	int rets;
1067 
1068 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1069 		return -ENODEV;
1070 
1071 	dev = cl->dev;
1072 
1073 	if (!mei_cl_bus_module_get(cl))
1074 		return -ENODEV;
1075 
1076 	rets = mei_cl_set_connecting(cl, me_cl);
1077 	if (rets)
1078 		goto nortpm;
1079 
1080 	if (mei_cl_is_fixed_address(cl)) {
1081 		cl->state = MEI_FILE_CONNECTED;
1082 		rets = 0;
1083 		goto nortpm;
1084 	}
1085 
1086 	rets = pm_runtime_get(dev->dev);
1087 	if (rets < 0 && rets != -EINPROGRESS) {
1088 		pm_runtime_put_noidle(dev->dev);
1089 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1090 		goto nortpm;
1091 	}
1092 
1093 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_CONNECT, fp);
1094 	if (!cb) {
1095 		rets = -ENOMEM;
1096 		goto out;
1097 	}
1098 
1099 	/* run hbuf acquire last so we don't have to undo */
1100 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1101 		rets = mei_cl_send_connect(cl, cb);
1102 		if (rets)
1103 			goto out;
1104 	}
1105 
1106 	mutex_unlock(&dev->device_lock);
1107 	wait_event_timeout(cl->wait,
1108 			(cl->state == MEI_FILE_CONNECTED ||
1109 			 cl->state == MEI_FILE_DISCONNECTED ||
1110 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1111 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1112 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1113 	mutex_lock(&dev->device_lock);
1114 
1115 	if (!mei_cl_is_connected(cl)) {
1116 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1117 			mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
1118 			mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
1119 			 /* ignore disconnect return valuue;
1120 			  * in case of failure reset will be invoked
1121 			  */
1122 			__mei_cl_disconnect(cl);
1123 			rets = -EFAULT;
1124 			goto out;
1125 		}
1126 
1127 		/* timeout or something went really wrong */
1128 		if (!cl->status)
1129 			cl->status = -EFAULT;
1130 	}
1131 
1132 	rets = cl->status;
1133 out:
1134 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1135 	pm_runtime_mark_last_busy(dev->dev);
1136 	pm_runtime_put_autosuspend(dev->dev);
1137 
1138 	mei_io_cb_free(cb);
1139 
1140 nortpm:
1141 	if (!mei_cl_is_connected(cl))
1142 		mei_cl_set_disconnected(cl);
1143 
1144 	return rets;
1145 }
1146 
1147 /**
1148  * mei_cl_alloc_linked - allocate and link host client
1149  *
1150  * @dev: the device structure
1151  *
1152  * Return: cl on success ERR_PTR on failure
1153  */
1154 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1155 {
1156 	struct mei_cl *cl;
1157 	int ret;
1158 
1159 	cl = mei_cl_allocate(dev);
1160 	if (!cl) {
1161 		ret = -ENOMEM;
1162 		goto err;
1163 	}
1164 
1165 	ret = mei_cl_link(cl);
1166 	if (ret)
1167 		goto err;
1168 
1169 	return cl;
1170 err:
1171 	kfree(cl);
1172 	return ERR_PTR(ret);
1173 }
1174 
1175 /**
1176  * mei_cl_tx_flow_ctrl_creds - checks flow_control credits for cl.
1177  *
1178  * @cl: host client
1179  *
1180  * Return: 1 if tx_flow_ctrl_creds >0, 0 - otherwise.
1181  */
1182 static int mei_cl_tx_flow_ctrl_creds(struct mei_cl *cl)
1183 {
1184 	if (WARN_ON(!cl || !cl->me_cl))
1185 		return -EINVAL;
1186 
1187 	if (cl->tx_flow_ctrl_creds > 0)
1188 		return 1;
1189 
1190 	if (mei_cl_is_fixed_address(cl))
1191 		return 1;
1192 
1193 	if (mei_cl_is_single_recv_buf(cl)) {
1194 		if (cl->me_cl->tx_flow_ctrl_creds > 0)
1195 			return 1;
1196 	}
1197 	return 0;
1198 }
1199 
1200 /**
1201  * mei_cl_tx_flow_ctrl_creds_reduce - reduces transmit flow control credits
1202  *   for a client
1203  *
1204  * @cl: host client
1205  *
1206  * Return:
1207  *	0 on success
1208  *	-EINVAL when ctrl credits are <= 0
1209  */
1210 static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
1211 {
1212 	if (WARN_ON(!cl || !cl->me_cl))
1213 		return -EINVAL;
1214 
1215 	if (mei_cl_is_fixed_address(cl))
1216 		return 0;
1217 
1218 	if (mei_cl_is_single_recv_buf(cl)) {
1219 		if (WARN_ON(cl->me_cl->tx_flow_ctrl_creds <= 0))
1220 			return -EINVAL;
1221 		cl->me_cl->tx_flow_ctrl_creds--;
1222 	} else {
1223 		if (WARN_ON(cl->tx_flow_ctrl_creds <= 0))
1224 			return -EINVAL;
1225 		cl->tx_flow_ctrl_creds--;
1226 	}
1227 	return 0;
1228 }
1229 
1230 /**
1231  *  mei_cl_notify_fop2req - convert fop to proper request
1232  *
1233  * @fop: client notification start response command
1234  *
1235  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1236  */
1237 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1238 {
1239 	if (fop == MEI_FOP_NOTIFY_START)
1240 		return MEI_HBM_NOTIFICATION_START;
1241 	else
1242 		return MEI_HBM_NOTIFICATION_STOP;
1243 }
1244 
1245 /**
1246  *  mei_cl_notify_req2fop - convert notification request top file operation type
1247  *
1248  * @req: hbm notification request type
1249  *
1250  * Return:  MEI_FOP_NOTIFY_START/STOP
1251  */
1252 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1253 {
1254 	if (req == MEI_HBM_NOTIFICATION_START)
1255 		return MEI_FOP_NOTIFY_START;
1256 	else
1257 		return MEI_FOP_NOTIFY_STOP;
1258 }
1259 
1260 /**
1261  * mei_cl_irq_notify - send notification request in irq_thread context
1262  *
1263  * @cl: client
1264  * @cb: callback block.
1265  * @cmpl_list: complete list.
1266  *
1267  * Return: 0 on such and error otherwise.
1268  */
1269 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1270 		      struct list_head *cmpl_list)
1271 {
1272 	struct mei_device *dev = cl->dev;
1273 	u32 msg_slots;
1274 	int slots;
1275 	int ret;
1276 	bool request;
1277 
1278 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1279 	slots = mei_hbuf_empty_slots(dev);
1280 
1281 	if (slots < msg_slots)
1282 		return -EMSGSIZE;
1283 
1284 	request = mei_cl_notify_fop2req(cb->fop_type);
1285 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1286 	if (ret) {
1287 		cl->status = ret;
1288 		list_move_tail(&cb->list, cmpl_list);
1289 		return ret;
1290 	}
1291 
1292 	list_move_tail(&cb->list, &dev->ctrl_rd_list);
1293 	return 0;
1294 }
1295 
1296 /**
1297  * mei_cl_notify_request - send notification stop/start request
1298  *
1299  * @cl: host client
1300  * @fp: associate request with file
1301  * @request: 1 for start or 0 for stop
1302  *
1303  * Locking: called under "dev->device_lock" lock
1304  *
1305  * Return: 0 on such and error otherwise.
1306  */
1307 int mei_cl_notify_request(struct mei_cl *cl,
1308 			  const struct file *fp, u8 request)
1309 {
1310 	struct mei_device *dev;
1311 	struct mei_cl_cb *cb;
1312 	enum mei_cb_file_ops fop_type;
1313 	int rets;
1314 
1315 	if (WARN_ON(!cl || !cl->dev))
1316 		return -ENODEV;
1317 
1318 	dev = cl->dev;
1319 
1320 	if (!dev->hbm_f_ev_supported) {
1321 		cl_dbg(dev, cl, "notifications not supported\n");
1322 		return -EOPNOTSUPP;
1323 	}
1324 
1325 	if (!mei_cl_is_connected(cl))
1326 		return -ENODEV;
1327 
1328 	rets = pm_runtime_get(dev->dev);
1329 	if (rets < 0 && rets != -EINPROGRESS) {
1330 		pm_runtime_put_noidle(dev->dev);
1331 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1332 		return rets;
1333 	}
1334 
1335 	fop_type = mei_cl_notify_req2fop(request);
1336 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1337 	if (!cb) {
1338 		rets = -ENOMEM;
1339 		goto out;
1340 	}
1341 
1342 	if (mei_hbuf_acquire(dev)) {
1343 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1344 			rets = -ENODEV;
1345 			goto out;
1346 		}
1347 		list_move_tail(&cb->list, &dev->ctrl_rd_list);
1348 	}
1349 
1350 	mutex_unlock(&dev->device_lock);
1351 	wait_event_timeout(cl->wait,
1352 			   cl->notify_en == request || !mei_cl_is_connected(cl),
1353 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1354 	mutex_lock(&dev->device_lock);
1355 
1356 	if (cl->notify_en != request && !cl->status)
1357 		cl->status = -EFAULT;
1358 
1359 	rets = cl->status;
1360 
1361 out:
1362 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1363 	pm_runtime_mark_last_busy(dev->dev);
1364 	pm_runtime_put_autosuspend(dev->dev);
1365 
1366 	mei_io_cb_free(cb);
1367 	return rets;
1368 }
1369 
1370 /**
1371  * mei_cl_notify - raise notification
1372  *
1373  * @cl: host client
1374  *
1375  * Locking: called under "dev->device_lock" lock
1376  */
1377 void mei_cl_notify(struct mei_cl *cl)
1378 {
1379 	struct mei_device *dev;
1380 
1381 	if (!cl || !cl->dev)
1382 		return;
1383 
1384 	dev = cl->dev;
1385 
1386 	if (!cl->notify_en)
1387 		return;
1388 
1389 	cl_dbg(dev, cl, "notify event");
1390 	cl->notify_ev = true;
1391 	if (!mei_cl_bus_notify_event(cl))
1392 		wake_up_interruptible(&cl->ev_wait);
1393 
1394 	if (cl->ev_async)
1395 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1396 
1397 }
1398 
1399 /**
1400  * mei_cl_notify_get - get or wait for notification event
1401  *
1402  * @cl: host client
1403  * @block: this request is blocking
1404  * @notify_ev: true if notification event was received
1405  *
1406  * Locking: called under "dev->device_lock" lock
1407  *
1408  * Return: 0 on such and error otherwise.
1409  */
1410 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1411 {
1412 	struct mei_device *dev;
1413 	int rets;
1414 
1415 	*notify_ev = false;
1416 
1417 	if (WARN_ON(!cl || !cl->dev))
1418 		return -ENODEV;
1419 
1420 	dev = cl->dev;
1421 
1422 	if (!dev->hbm_f_ev_supported) {
1423 		cl_dbg(dev, cl, "notifications not supported\n");
1424 		return -EOPNOTSUPP;
1425 	}
1426 
1427 	if (!mei_cl_is_connected(cl))
1428 		return -ENODEV;
1429 
1430 	if (cl->notify_ev)
1431 		goto out;
1432 
1433 	if (!block)
1434 		return -EAGAIN;
1435 
1436 	mutex_unlock(&dev->device_lock);
1437 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1438 	mutex_lock(&dev->device_lock);
1439 
1440 	if (rets < 0)
1441 		return rets;
1442 
1443 out:
1444 	*notify_ev = cl->notify_ev;
1445 	cl->notify_ev = false;
1446 	return 0;
1447 }
1448 
1449 /**
1450  * mei_cl_read_start - the start read client message function.
1451  *
1452  * @cl: host client
1453  * @length: number of bytes to read
1454  * @fp: pointer to file structure
1455  *
1456  * Return: 0 on success, <0 on failure.
1457  */
1458 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1459 {
1460 	struct mei_device *dev;
1461 	struct mei_cl_cb *cb;
1462 	int rets;
1463 
1464 	if (WARN_ON(!cl || !cl->dev))
1465 		return -ENODEV;
1466 
1467 	dev = cl->dev;
1468 
1469 	if (!mei_cl_is_connected(cl))
1470 		return -ENODEV;
1471 
1472 	if (!mei_me_cl_is_active(cl->me_cl)) {
1473 		cl_err(dev, cl, "no such me client\n");
1474 		return  -ENOTTY;
1475 	}
1476 
1477 	if (mei_cl_is_fixed_address(cl))
1478 		return 0;
1479 
1480 	/* HW currently supports only one pending read */
1481 	if (cl->rx_flow_ctrl_creds)
1482 		return -EBUSY;
1483 
1484 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1485 	if (!cb)
1486 		return -ENOMEM;
1487 
1488 	rets = pm_runtime_get(dev->dev);
1489 	if (rets < 0 && rets != -EINPROGRESS) {
1490 		pm_runtime_put_noidle(dev->dev);
1491 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1492 		goto nortpm;
1493 	}
1494 
1495 	rets = 0;
1496 	if (mei_hbuf_acquire(dev)) {
1497 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1498 		if (rets < 0)
1499 			goto out;
1500 
1501 		list_move_tail(&cb->list, &cl->rd_pending);
1502 	}
1503 	cl->rx_flow_ctrl_creds++;
1504 
1505 out:
1506 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1507 	pm_runtime_mark_last_busy(dev->dev);
1508 	pm_runtime_put_autosuspend(dev->dev);
1509 nortpm:
1510 	if (rets)
1511 		mei_io_cb_free(cb);
1512 
1513 	return rets;
1514 }
1515 
1516 /**
1517  * mei_cl_irq_write - write a message to device
1518  *	from the interrupt thread context
1519  *
1520  * @cl: client
1521  * @cb: callback block.
1522  * @cmpl_list: complete list.
1523  *
1524  * Return: 0, OK; otherwise error.
1525  */
1526 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1527 		     struct list_head *cmpl_list)
1528 {
1529 	struct mei_device *dev;
1530 	struct mei_msg_data *buf;
1531 	struct mei_msg_hdr mei_hdr;
1532 	size_t len;
1533 	u32 msg_slots;
1534 	int slots;
1535 	int rets;
1536 	bool first_chunk;
1537 
1538 	if (WARN_ON(!cl || !cl->dev))
1539 		return -ENODEV;
1540 
1541 	dev = cl->dev;
1542 
1543 	buf = &cb->buf;
1544 
1545 	first_chunk = cb->buf_idx == 0;
1546 
1547 	rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1548 	if (rets < 0)
1549 		goto err;
1550 
1551 	if (rets == 0) {
1552 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1553 		return 0;
1554 	}
1555 
1556 	slots = mei_hbuf_empty_slots(dev);
1557 	len = buf->size - cb->buf_idx;
1558 	msg_slots = mei_data2slots(len);
1559 
1560 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1561 	mei_hdr.me_addr = mei_cl_me_id(cl);
1562 	mei_hdr.reserved = 0;
1563 	mei_hdr.internal = cb->internal;
1564 
1565 	if (slots >= msg_slots) {
1566 		mei_hdr.length = len;
1567 		mei_hdr.msg_complete = 1;
1568 	/* Split the message only if we can write the whole host buffer */
1569 	} else if (slots == dev->hbuf_depth) {
1570 		msg_slots = slots;
1571 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1572 		mei_hdr.length = len;
1573 		mei_hdr.msg_complete = 0;
1574 	} else {
1575 		/* wait for next time the host buffer is empty */
1576 		return 0;
1577 	}
1578 
1579 	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1580 			cb->buf.size, cb->buf_idx);
1581 
1582 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1583 	if (rets)
1584 		goto err;
1585 
1586 	cl->status = 0;
1587 	cl->writing_state = MEI_WRITING;
1588 	cb->buf_idx += mei_hdr.length;
1589 	cb->completed = mei_hdr.msg_complete == 1;
1590 
1591 	if (first_chunk) {
1592 		if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
1593 			rets = -EIO;
1594 			goto err;
1595 		}
1596 	}
1597 
1598 	if (mei_hdr.msg_complete)
1599 		list_move_tail(&cb->list, &dev->write_waiting_list);
1600 
1601 	return 0;
1602 
1603 err:
1604 	cl->status = rets;
1605 	list_move_tail(&cb->list, cmpl_list);
1606 	return rets;
1607 }
1608 
1609 /**
1610  * mei_cl_write - submit a write cb to mei device
1611  *	assumes device_lock is locked
1612  *
1613  * @cl: host client
1614  * @cb: write callback with filled data
1615  *
1616  * Return: number of bytes sent on success, <0 on failure.
1617  */
1618 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
1619 {
1620 	struct mei_device *dev;
1621 	struct mei_msg_data *buf;
1622 	struct mei_msg_hdr mei_hdr;
1623 	int size;
1624 	int rets;
1625 	bool blocking;
1626 
1627 	if (WARN_ON(!cl || !cl->dev))
1628 		return -ENODEV;
1629 
1630 	if (WARN_ON(!cb))
1631 		return -EINVAL;
1632 
1633 	dev = cl->dev;
1634 
1635 	buf = &cb->buf;
1636 	size = buf->size;
1637 	blocking = cb->blocking;
1638 
1639 	cl_dbg(dev, cl, "size=%d\n", size);
1640 
1641 	rets = pm_runtime_get(dev->dev);
1642 	if (rets < 0 && rets != -EINPROGRESS) {
1643 		pm_runtime_put_noidle(dev->dev);
1644 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1645 		goto free;
1646 	}
1647 
1648 	cb->buf_idx = 0;
1649 	cl->writing_state = MEI_IDLE;
1650 
1651 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1652 	mei_hdr.me_addr = mei_cl_me_id(cl);
1653 	mei_hdr.reserved = 0;
1654 	mei_hdr.msg_complete = 0;
1655 	mei_hdr.internal = cb->internal;
1656 
1657 	rets = mei_cl_tx_flow_ctrl_creds(cl);
1658 	if (rets < 0)
1659 		goto err;
1660 
1661 	if (rets == 0) {
1662 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1663 		rets = size;
1664 		goto out;
1665 	}
1666 	if (!mei_hbuf_acquire(dev)) {
1667 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1668 		rets = size;
1669 		goto out;
1670 	}
1671 
1672 	/* Check for a maximum length */
1673 	if (size > mei_hbuf_max_len(dev)) {
1674 		mei_hdr.length = mei_hbuf_max_len(dev);
1675 		mei_hdr.msg_complete = 0;
1676 	} else {
1677 		mei_hdr.length = size;
1678 		mei_hdr.msg_complete = 1;
1679 	}
1680 
1681 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1682 	if (rets)
1683 		goto err;
1684 
1685 	rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1686 	if (rets)
1687 		goto err;
1688 
1689 	cl->writing_state = MEI_WRITING;
1690 	cb->buf_idx = mei_hdr.length;
1691 	cb->completed = mei_hdr.msg_complete == 1;
1692 
1693 out:
1694 	if (mei_hdr.msg_complete)
1695 		list_add_tail(&cb->list, &dev->write_waiting_list);
1696 	else
1697 		list_add_tail(&cb->list, &dev->write_list);
1698 
1699 	cb = NULL;
1700 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1701 
1702 		mutex_unlock(&dev->device_lock);
1703 		rets = wait_event_interruptible(cl->tx_wait,
1704 				cl->writing_state == MEI_WRITE_COMPLETE ||
1705 				(!mei_cl_is_connected(cl)));
1706 		mutex_lock(&dev->device_lock);
1707 		/* wait_event_interruptible returns -ERESTARTSYS */
1708 		if (rets) {
1709 			if (signal_pending(current))
1710 				rets = -EINTR;
1711 			goto err;
1712 		}
1713 		if (cl->writing_state != MEI_WRITE_COMPLETE) {
1714 			rets = -EFAULT;
1715 			goto err;
1716 		}
1717 	}
1718 
1719 	rets = size;
1720 err:
1721 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1722 	pm_runtime_mark_last_busy(dev->dev);
1723 	pm_runtime_put_autosuspend(dev->dev);
1724 free:
1725 	mei_io_cb_free(cb);
1726 
1727 	return rets;
1728 }
1729 
1730 
1731 /**
1732  * mei_cl_complete - processes completed operation for a client
1733  *
1734  * @cl: private data of the file object.
1735  * @cb: callback block.
1736  */
1737 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1738 {
1739 	struct mei_device *dev = cl->dev;
1740 
1741 	switch (cb->fop_type) {
1742 	case MEI_FOP_WRITE:
1743 		mei_io_cb_free(cb);
1744 		cl->writing_state = MEI_WRITE_COMPLETE;
1745 		if (waitqueue_active(&cl->tx_wait)) {
1746 			wake_up_interruptible(&cl->tx_wait);
1747 		} else {
1748 			pm_runtime_mark_last_busy(dev->dev);
1749 			pm_request_autosuspend(dev->dev);
1750 		}
1751 		break;
1752 
1753 	case MEI_FOP_READ:
1754 		list_add_tail(&cb->list, &cl->rd_completed);
1755 		if (!mei_cl_is_fixed_address(cl) &&
1756 		    !WARN_ON(!cl->rx_flow_ctrl_creds))
1757 			cl->rx_flow_ctrl_creds--;
1758 		if (!mei_cl_bus_rx_event(cl))
1759 			wake_up_interruptible(&cl->rx_wait);
1760 		break;
1761 
1762 	case MEI_FOP_CONNECT:
1763 	case MEI_FOP_DISCONNECT:
1764 	case MEI_FOP_NOTIFY_STOP:
1765 	case MEI_FOP_NOTIFY_START:
1766 		if (waitqueue_active(&cl->wait))
1767 			wake_up(&cl->wait);
1768 
1769 		break;
1770 	case MEI_FOP_DISCONNECT_RSP:
1771 		mei_io_cb_free(cb);
1772 		mei_cl_set_disconnected(cl);
1773 		break;
1774 	default:
1775 		BUG_ON(0);
1776 	}
1777 }
1778 
1779 
1780 /**
1781  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1782  *
1783  * @dev: mei device
1784  */
1785 void mei_cl_all_disconnect(struct mei_device *dev)
1786 {
1787 	struct mei_cl *cl;
1788 
1789 	list_for_each_entry(cl, &dev->file_list, link)
1790 		mei_cl_set_disconnected(cl);
1791 }
1792