xref: /openbmc/linux/drivers/misc/mei/client.c (revision f6723b56)
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/pci.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/delay.h>
21 
22 #include <linux/mei.h>
23 
24 #include "mei_dev.h"
25 #include "hbm.h"
26 #include "client.h"
27 
28 /**
29  * mei_me_cl_by_uuid - locate index of me client
30  *
31  * @dev: mei device
32  * returns me client index or -ENOENT if not found
33  */
34 int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *uuid)
35 {
36 	int i, res = -ENOENT;
37 
38 	for (i = 0; i < dev->me_clients_num; ++i)
39 		if (uuid_le_cmp(*uuid,
40 				dev->me_clients[i].props.protocol_name) == 0) {
41 			res = i;
42 			break;
43 		}
44 
45 	return res;
46 }
47 
48 
49 /**
50  * mei_me_cl_by_id return index to me_clients for client_id
51  *
52  * @dev: the device structure
53  * @client_id: me client id
54  *
55  * Locking: called under "dev->device_lock" lock
56  *
57  * returns index on success, -ENOENT on failure.
58  */
59 
60 int mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
61 {
62 	int i;
63 	for (i = 0; i < dev->me_clients_num; i++)
64 		if (dev->me_clients[i].client_id == client_id)
65 			break;
66 	if (WARN_ON(dev->me_clients[i].client_id != client_id))
67 		return -ENOENT;
68 
69 	if (i == dev->me_clients_num)
70 		return -ENOENT;
71 
72 	return i;
73 }
74 
75 
76 /**
77  * mei_io_list_flush - removes list entry belonging to cl.
78  *
79  * @list:  An instance of our list structure
80  * @cl: host client
81  */
82 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
83 {
84 	struct mei_cl_cb *cb;
85 	struct mei_cl_cb *next;
86 
87 	list_for_each_entry_safe(cb, next, &list->list, list) {
88 		if (cb->cl && mei_cl_cmp_id(cl, cb->cl))
89 			list_del(&cb->list);
90 	}
91 }
92 
93 /**
94  * mei_io_cb_free - free mei_cb_private related memory
95  *
96  * @cb: mei callback struct
97  */
98 void mei_io_cb_free(struct mei_cl_cb *cb)
99 {
100 	if (cb == NULL)
101 		return;
102 
103 	kfree(cb->request_buffer.data);
104 	kfree(cb->response_buffer.data);
105 	kfree(cb);
106 }
107 
108 /**
109  * mei_io_cb_init - allocate and initialize io callback
110  *
111  * @cl - mei client
112  * @fp: pointer to file structure
113  *
114  * returns mei_cl_cb pointer or NULL;
115  */
116 struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, struct file *fp)
117 {
118 	struct mei_cl_cb *cb;
119 
120 	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
121 	if (!cb)
122 		return NULL;
123 
124 	mei_io_list_init(cb);
125 
126 	cb->file_object = fp;
127 	cb->cl = cl;
128 	cb->buf_idx = 0;
129 	return cb;
130 }
131 
132 /**
133  * mei_io_cb_alloc_req_buf - allocate request buffer
134  *
135  * @cb: io callback structure
136  * @length: size of the buffer
137  *
138  * returns 0 on success
139  *         -EINVAL if cb is NULL
140  *         -ENOMEM if allocation failed
141  */
142 int mei_io_cb_alloc_req_buf(struct mei_cl_cb *cb, size_t length)
143 {
144 	if (!cb)
145 		return -EINVAL;
146 
147 	if (length == 0)
148 		return 0;
149 
150 	cb->request_buffer.data = kmalloc(length, GFP_KERNEL);
151 	if (!cb->request_buffer.data)
152 		return -ENOMEM;
153 	cb->request_buffer.size = length;
154 	return 0;
155 }
156 /**
157  * mei_io_cb_alloc_resp_buf - allocate response buffer
158  *
159  * @cb: io callback structure
160  * @length: size of the buffer
161  *
162  * returns 0 on success
163  *         -EINVAL if cb is NULL
164  *         -ENOMEM if allocation failed
165  */
166 int mei_io_cb_alloc_resp_buf(struct mei_cl_cb *cb, size_t length)
167 {
168 	if (!cb)
169 		return -EINVAL;
170 
171 	if (length == 0)
172 		return 0;
173 
174 	cb->response_buffer.data = kmalloc(length, GFP_KERNEL);
175 	if (!cb->response_buffer.data)
176 		return -ENOMEM;
177 	cb->response_buffer.size = length;
178 	return 0;
179 }
180 
181 
182 
183 /**
184  * mei_cl_flush_queues - flushes queue lists belonging to cl.
185  *
186  * @cl: host client
187  */
188 int mei_cl_flush_queues(struct mei_cl *cl)
189 {
190 	struct mei_device *dev;
191 
192 	if (WARN_ON(!cl || !cl->dev))
193 		return -EINVAL;
194 
195 	dev = cl->dev;
196 
197 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
198 	mei_io_list_flush(&cl->dev->read_list, cl);
199 	mei_io_list_flush(&cl->dev->write_list, cl);
200 	mei_io_list_flush(&cl->dev->write_waiting_list, cl);
201 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
202 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
203 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
204 	mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
205 	return 0;
206 }
207 
208 
209 /**
210  * mei_cl_init - initializes cl.
211  *
212  * @cl: host client to be initialized
213  * @dev: mei device
214  */
215 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
216 {
217 	memset(cl, 0, sizeof(struct mei_cl));
218 	init_waitqueue_head(&cl->wait);
219 	init_waitqueue_head(&cl->rx_wait);
220 	init_waitqueue_head(&cl->tx_wait);
221 	INIT_LIST_HEAD(&cl->link);
222 	INIT_LIST_HEAD(&cl->device_link);
223 	cl->reading_state = MEI_IDLE;
224 	cl->writing_state = MEI_IDLE;
225 	cl->dev = dev;
226 }
227 
228 /**
229  * mei_cl_allocate - allocates cl  structure and sets it up.
230  *
231  * @dev: mei device
232  * returns  The allocated file or NULL on failure
233  */
234 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
235 {
236 	struct mei_cl *cl;
237 
238 	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
239 	if (!cl)
240 		return NULL;
241 
242 	mei_cl_init(cl, dev);
243 
244 	return cl;
245 }
246 
247 /**
248  * mei_cl_find_read_cb - find this cl's callback in the read list
249  *
250  * @cl: host client
251  *
252  * returns cb on success, NULL on error
253  */
254 struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)
255 {
256 	struct mei_device *dev = cl->dev;
257 	struct mei_cl_cb *cb = NULL;
258 	struct mei_cl_cb *next = NULL;
259 
260 	list_for_each_entry_safe(cb, next, &dev->read_list.list, list)
261 		if (mei_cl_cmp_id(cl, cb->cl))
262 			return cb;
263 	return NULL;
264 }
265 
266 /** mei_cl_link: allocate host id in the host map
267  *
268  * @cl - host client
269  * @id - fixed host id or -1 for generic one
270  *
271  * returns 0 on success
272  *	-EINVAL on incorrect values
273  *	-ENONET if client not found
274  */
275 int mei_cl_link(struct mei_cl *cl, int id)
276 {
277 	struct mei_device *dev;
278 	long open_handle_count;
279 
280 	if (WARN_ON(!cl || !cl->dev))
281 		return -EINVAL;
282 
283 	dev = cl->dev;
284 
285 	/* If Id is not assigned get one*/
286 	if (id == MEI_HOST_CLIENT_ID_ANY)
287 		id = find_first_zero_bit(dev->host_clients_map,
288 					MEI_CLIENTS_MAX);
289 
290 	if (id >= MEI_CLIENTS_MAX) {
291 		dev_err(&dev->pdev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
292 		return -EMFILE;
293 	}
294 
295 	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
296 	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
297 		dev_err(&dev->pdev->dev, "open_handle_count exceeded %d",
298 			MEI_MAX_OPEN_HANDLE_COUNT);
299 		return -EMFILE;
300 	}
301 
302 	dev->open_handle_count++;
303 
304 	cl->host_client_id = id;
305 	list_add_tail(&cl->link, &dev->file_list);
306 
307 	set_bit(id, dev->host_clients_map);
308 
309 	cl->state = MEI_FILE_INITIALIZING;
310 
311 	cl_dbg(dev, cl, "link cl\n");
312 	return 0;
313 }
314 
315 /**
316  * mei_cl_unlink - remove me_cl from the list
317  *
318  * @cl: host client
319  */
320 int mei_cl_unlink(struct mei_cl *cl)
321 {
322 	struct mei_device *dev;
323 
324 	/* don't shout on error exit path */
325 	if (!cl)
326 		return 0;
327 
328 	/* wd and amthif might not be initialized */
329 	if (!cl->dev)
330 		return 0;
331 
332 	dev = cl->dev;
333 
334 	cl_dbg(dev, cl, "unlink client");
335 
336 	if (dev->open_handle_count > 0)
337 		dev->open_handle_count--;
338 
339 	/* never clear the 0 bit */
340 	if (cl->host_client_id)
341 		clear_bit(cl->host_client_id, dev->host_clients_map);
342 
343 	list_del_init(&cl->link);
344 
345 	cl->state = MEI_FILE_INITIALIZING;
346 
347 	return 0;
348 }
349 
350 
351 void mei_host_client_init(struct work_struct *work)
352 {
353 	struct mei_device *dev = container_of(work,
354 					      struct mei_device, init_work);
355 	struct mei_client_properties *client_props;
356 	int i;
357 
358 	mutex_lock(&dev->device_lock);
359 
360 	for (i = 0; i < dev->me_clients_num; i++) {
361 		client_props = &dev->me_clients[i].props;
362 
363 		if (!uuid_le_cmp(client_props->protocol_name, mei_amthif_guid))
364 			mei_amthif_host_init(dev);
365 		else if (!uuid_le_cmp(client_props->protocol_name, mei_wd_guid))
366 			mei_wd_host_init(dev);
367 		else if (!uuid_le_cmp(client_props->protocol_name, mei_nfc_guid))
368 			mei_nfc_host_init(dev);
369 
370 	}
371 
372 	dev->dev_state = MEI_DEV_ENABLED;
373 	dev->reset_count = 0;
374 
375 	mutex_unlock(&dev->device_lock);
376 }
377 
378 
379 /**
380  * mei_cl_disconnect - disconnect host client from the me one
381  *
382  * @cl: host client
383  *
384  * Locking: called under "dev->device_lock" lock
385  *
386  * returns 0 on success, <0 on failure.
387  */
388 int mei_cl_disconnect(struct mei_cl *cl)
389 {
390 	struct mei_device *dev;
391 	struct mei_cl_cb *cb;
392 	int rets, err;
393 
394 	if (WARN_ON(!cl || !cl->dev))
395 		return -ENODEV;
396 
397 	dev = cl->dev;
398 
399 	cl_dbg(dev, cl, "disconnecting");
400 
401 	if (cl->state != MEI_FILE_DISCONNECTING)
402 		return 0;
403 
404 	cb = mei_io_cb_init(cl, NULL);
405 	if (!cb)
406 		return -ENOMEM;
407 
408 	cb->fop_type = MEI_FOP_CLOSE;
409 	if (dev->hbuf_is_ready) {
410 		dev->hbuf_is_ready = false;
411 		if (mei_hbm_cl_disconnect_req(dev, cl)) {
412 			rets = -ENODEV;
413 			cl_err(dev, cl, "failed to disconnect.\n");
414 			goto free;
415 		}
416 		mdelay(10); /* Wait for hardware disconnection ready */
417 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
418 	} else {
419 		cl_dbg(dev, cl, "add disconnect cb to control write list\n");
420 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
421 
422 	}
423 	mutex_unlock(&dev->device_lock);
424 
425 	err = wait_event_timeout(dev->wait_recvd_msg,
426 			MEI_FILE_DISCONNECTED == cl->state,
427 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
428 
429 	mutex_lock(&dev->device_lock);
430 	if (MEI_FILE_DISCONNECTED == cl->state) {
431 		rets = 0;
432 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
433 	} else {
434 		rets = -ENODEV;
435 		if (MEI_FILE_DISCONNECTED != cl->state)
436 			cl_err(dev, cl, "wrong status client disconnect.\n");
437 
438 		if (err)
439 			cl_dbg(dev, cl, "wait failed disconnect err=%08x\n",
440 					err);
441 
442 		cl_err(dev, cl, "failed to disconnect from FW client.\n");
443 	}
444 
445 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
446 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
447 free:
448 	mei_io_cb_free(cb);
449 	return rets;
450 }
451 
452 
453 /**
454  * mei_cl_is_other_connecting - checks if other
455  *    client with the same me client id is connecting
456  *
457  * @cl: private data of the file object
458  *
459  * returns true if other client is connected, false - otherwise.
460  */
461 bool mei_cl_is_other_connecting(struct mei_cl *cl)
462 {
463 	struct mei_device *dev;
464 	struct mei_cl *pos;
465 	struct mei_cl *next;
466 
467 	if (WARN_ON(!cl || !cl->dev))
468 		return false;
469 
470 	dev = cl->dev;
471 
472 	list_for_each_entry_safe(pos, next, &dev->file_list, link) {
473 		if ((pos->state == MEI_FILE_CONNECTING) &&
474 		    (pos != cl) && cl->me_client_id == pos->me_client_id)
475 			return true;
476 
477 	}
478 
479 	return false;
480 }
481 
482 /**
483  * mei_cl_connect - connect host client to the me one
484  *
485  * @cl: host client
486  *
487  * Locking: called under "dev->device_lock" lock
488  *
489  * returns 0 on success, <0 on failure.
490  */
491 int mei_cl_connect(struct mei_cl *cl, struct file *file)
492 {
493 	struct mei_device *dev;
494 	struct mei_cl_cb *cb;
495 	int rets;
496 
497 	if (WARN_ON(!cl || !cl->dev))
498 		return -ENODEV;
499 
500 	dev = cl->dev;
501 
502 	cb = mei_io_cb_init(cl, file);
503 	if (!cb) {
504 		rets = -ENOMEM;
505 		goto out;
506 	}
507 
508 	cb->fop_type = MEI_FOP_IOCTL;
509 
510 	if (dev->hbuf_is_ready && !mei_cl_is_other_connecting(cl)) {
511 		dev->hbuf_is_ready = false;
512 
513 		if (mei_hbm_cl_connect_req(dev, cl)) {
514 			rets = -ENODEV;
515 			goto out;
516 		}
517 		cl->timer_count = MEI_CONNECT_TIMEOUT;
518 		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
519 	} else {
520 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
521 	}
522 
523 	mutex_unlock(&dev->device_lock);
524 	rets = wait_event_timeout(dev->wait_recvd_msg,
525 				 (cl->state == MEI_FILE_CONNECTED ||
526 				  cl->state == MEI_FILE_DISCONNECTED),
527 				 mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
528 	mutex_lock(&dev->device_lock);
529 
530 	if (cl->state != MEI_FILE_CONNECTED) {
531 		rets = -EFAULT;
532 
533 		mei_io_list_flush(&dev->ctrl_rd_list, cl);
534 		mei_io_list_flush(&dev->ctrl_wr_list, cl);
535 		goto out;
536 	}
537 
538 	rets = cl->status;
539 
540 out:
541 	mei_io_cb_free(cb);
542 	return rets;
543 }
544 
545 /**
546  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
547  *
548  * @cl: private data of the file object
549  *
550  * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
551  *	-ENOENT if mei_cl is not present
552  *	-EINVAL if single_recv_buf == 0
553  */
554 int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
555 {
556 	struct mei_device *dev;
557 	int i;
558 
559 	if (WARN_ON(!cl || !cl->dev))
560 		return -EINVAL;
561 
562 	dev = cl->dev;
563 
564 	if (!dev->me_clients_num)
565 		return 0;
566 
567 	if (cl->mei_flow_ctrl_creds > 0)
568 		return 1;
569 
570 	for (i = 0; i < dev->me_clients_num; i++) {
571 		struct mei_me_client  *me_cl = &dev->me_clients[i];
572 		if (me_cl->client_id == cl->me_client_id) {
573 			if (me_cl->mei_flow_ctrl_creds) {
574 				if (WARN_ON(me_cl->props.single_recv_buf == 0))
575 					return -EINVAL;
576 				return 1;
577 			} else {
578 				return 0;
579 			}
580 		}
581 	}
582 	return -ENOENT;
583 }
584 
585 /**
586  * mei_cl_flow_ctrl_reduce - reduces flow_control.
587  *
588  * @cl: private data of the file object
589  *
590  * @returns
591  *	0 on success
592  *	-ENOENT when me client is not found
593  *	-EINVAL when ctrl credits are <= 0
594  */
595 int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
596 {
597 	struct mei_device *dev;
598 	int i;
599 
600 	if (WARN_ON(!cl || !cl->dev))
601 		return -EINVAL;
602 
603 	dev = cl->dev;
604 
605 	if (!dev->me_clients_num)
606 		return -ENOENT;
607 
608 	for (i = 0; i < dev->me_clients_num; i++) {
609 		struct mei_me_client  *me_cl = &dev->me_clients[i];
610 		if (me_cl->client_id == cl->me_client_id) {
611 			if (me_cl->props.single_recv_buf != 0) {
612 				if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
613 					return -EINVAL;
614 				dev->me_clients[i].mei_flow_ctrl_creds--;
615 			} else {
616 				if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
617 					return -EINVAL;
618 				cl->mei_flow_ctrl_creds--;
619 			}
620 			return 0;
621 		}
622 	}
623 	return -ENOENT;
624 }
625 
626 /**
627  * mei_cl_read_start - the start read client message function.
628  *
629  * @cl: host client
630  *
631  * returns 0 on success, <0 on failure.
632  */
633 int mei_cl_read_start(struct mei_cl *cl, size_t length)
634 {
635 	struct mei_device *dev;
636 	struct mei_cl_cb *cb;
637 	int rets;
638 	int i;
639 
640 	if (WARN_ON(!cl || !cl->dev))
641 		return -ENODEV;
642 
643 	dev = cl->dev;
644 
645 	if (!mei_cl_is_connected(cl))
646 		return -ENODEV;
647 
648 	if (cl->read_cb) {
649 		cl_dbg(dev, cl, "read is pending.\n");
650 		return -EBUSY;
651 	}
652 	i = mei_me_cl_by_id(dev, cl->me_client_id);
653 	if (i < 0) {
654 		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
655 		return  -ENODEV;
656 	}
657 
658 	cb = mei_io_cb_init(cl, NULL);
659 	if (!cb)
660 		return -ENOMEM;
661 
662 	/* always allocate at least client max message */
663 	length = max_t(size_t, length, dev->me_clients[i].props.max_msg_length);
664 	rets = mei_io_cb_alloc_resp_buf(cb, length);
665 	if (rets)
666 		goto err;
667 
668 	cb->fop_type = MEI_FOP_READ;
669 	cl->read_cb = cb;
670 	if (dev->hbuf_is_ready) {
671 		dev->hbuf_is_ready = false;
672 		if (mei_hbm_cl_flow_control_req(dev, cl)) {
673 			cl_err(dev, cl, "flow control send failed\n");
674 			rets = -ENODEV;
675 			goto err;
676 		}
677 		list_add_tail(&cb->list, &dev->read_list.list);
678 	} else {
679 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
680 	}
681 	return rets;
682 err:
683 	mei_io_cb_free(cb);
684 	return rets;
685 }
686 
687 /**
688  * mei_cl_irq_write_complete - write a message to device
689  *	from the interrupt thread context
690  *
691  * @cl: client
692  * @cb: callback block.
693  * @slots: free slots.
694  * @cmpl_list: complete list.
695  *
696  * returns 0, OK; otherwise error.
697  */
698 int mei_cl_irq_write_complete(struct mei_cl *cl, struct mei_cl_cb *cb,
699 				     s32 *slots, struct mei_cl_cb *cmpl_list)
700 {
701 	struct mei_device *dev;
702 	struct mei_msg_data *buf;
703 	struct mei_msg_hdr mei_hdr;
704 	size_t len;
705 	u32 msg_slots;
706 	int rets;
707 
708 
709 	if (WARN_ON(!cl || !cl->dev))
710 		return -ENODEV;
711 
712 	dev = cl->dev;
713 
714 	buf = &cb->request_buffer;
715 
716 	rets = mei_cl_flow_ctrl_creds(cl);
717 	if (rets < 0)
718 		return rets;
719 
720 	if (rets == 0) {
721 		cl_dbg(dev, cl,	"No flow control credentials: not sending.\n");
722 		return 0;
723 	}
724 
725 	len = buf->size - cb->buf_idx;
726 	msg_slots = mei_data2slots(len);
727 
728 	mei_hdr.host_addr = cl->host_client_id;
729 	mei_hdr.me_addr = cl->me_client_id;
730 	mei_hdr.reserved = 0;
731 	mei_hdr.internal = cb->internal;
732 
733 	if (*slots >= msg_slots) {
734 		mei_hdr.length = len;
735 		mei_hdr.msg_complete = 1;
736 	/* Split the message only if we can write the whole host buffer */
737 	} else if (*slots == dev->hbuf_depth) {
738 		msg_slots = *slots;
739 		len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
740 		mei_hdr.length = len;
741 		mei_hdr.msg_complete = 0;
742 	} else {
743 		/* wait for next time the host buffer is empty */
744 		return 0;
745 	}
746 
747 	cl_dbg(dev, cl, "buf: size = %d idx = %lu\n",
748 			cb->request_buffer.size, cb->buf_idx);
749 
750 	*slots -=  msg_slots;
751 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
752 	if (rets) {
753 		cl->status = rets;
754 		list_move_tail(&cb->list, &cmpl_list->list);
755 		return rets;
756 	}
757 
758 	cl->status = 0;
759 	cl->writing_state = MEI_WRITING;
760 	cb->buf_idx += mei_hdr.length;
761 
762 	if (mei_hdr.msg_complete) {
763 		if (mei_cl_flow_ctrl_reduce(cl))
764 			return -EIO;
765 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
766 	}
767 
768 	return 0;
769 }
770 
771 /**
772  * mei_cl_write - submit a write cb to mei device
773 	assumes device_lock is locked
774  *
775  * @cl: host client
776  * @cl: write callback with filled data
777  *
778  * returns number of bytes sent on success, <0 on failure.
779  */
780 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
781 {
782 	struct mei_device *dev;
783 	struct mei_msg_data *buf;
784 	struct mei_msg_hdr mei_hdr;
785 	int rets;
786 
787 
788 	if (WARN_ON(!cl || !cl->dev))
789 		return -ENODEV;
790 
791 	if (WARN_ON(!cb))
792 		return -EINVAL;
793 
794 	dev = cl->dev;
795 
796 
797 	buf = &cb->request_buffer;
798 
799 	cl_dbg(dev, cl, "mei_cl_write %d\n", buf->size);
800 
801 
802 	cb->fop_type = MEI_FOP_WRITE;
803 
804 	rets = mei_cl_flow_ctrl_creds(cl);
805 	if (rets < 0)
806 		goto err;
807 
808 	/* Host buffer is not ready, we queue the request */
809 	if (rets == 0 || !dev->hbuf_is_ready) {
810 		cb->buf_idx = 0;
811 		/* unseting complete will enqueue the cb for write */
812 		mei_hdr.msg_complete = 0;
813 		rets = buf->size;
814 		goto out;
815 	}
816 
817 	dev->hbuf_is_ready = false;
818 
819 	/* Check for a maximum length */
820 	if (buf->size > mei_hbuf_max_len(dev)) {
821 		mei_hdr.length = mei_hbuf_max_len(dev);
822 		mei_hdr.msg_complete = 0;
823 	} else {
824 		mei_hdr.length = buf->size;
825 		mei_hdr.msg_complete = 1;
826 	}
827 
828 	mei_hdr.host_addr = cl->host_client_id;
829 	mei_hdr.me_addr = cl->me_client_id;
830 	mei_hdr.reserved = 0;
831 	mei_hdr.internal = cb->internal;
832 
833 
834 	rets = mei_write_message(dev, &mei_hdr, buf->data);
835 	if (rets)
836 		goto err;
837 
838 	cl->writing_state = MEI_WRITING;
839 	cb->buf_idx = mei_hdr.length;
840 
841 	rets = buf->size;
842 out:
843 	if (mei_hdr.msg_complete) {
844 		if (mei_cl_flow_ctrl_reduce(cl)) {
845 			rets = -ENODEV;
846 			goto err;
847 		}
848 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
849 	} else {
850 		list_add_tail(&cb->list, &dev->write_list.list);
851 	}
852 
853 
854 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
855 
856 		mutex_unlock(&dev->device_lock);
857 		if (wait_event_interruptible(cl->tx_wait,
858 			cl->writing_state == MEI_WRITE_COMPLETE)) {
859 				if (signal_pending(current))
860 					rets = -EINTR;
861 				else
862 					rets = -ERESTARTSYS;
863 		}
864 		mutex_lock(&dev->device_lock);
865 	}
866 err:
867 	return rets;
868 }
869 
870 
871 /**
872  * mei_cl_complete - processes completed operation for a client
873  *
874  * @cl: private data of the file object.
875  * @cb: callback block.
876  */
877 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
878 {
879 	if (cb->fop_type == MEI_FOP_WRITE) {
880 		mei_io_cb_free(cb);
881 		cb = NULL;
882 		cl->writing_state = MEI_WRITE_COMPLETE;
883 		if (waitqueue_active(&cl->tx_wait))
884 			wake_up_interruptible(&cl->tx_wait);
885 
886 	} else if (cb->fop_type == MEI_FOP_READ &&
887 			MEI_READING == cl->reading_state) {
888 		cl->reading_state = MEI_READ_COMPLETE;
889 		if (waitqueue_active(&cl->rx_wait))
890 			wake_up_interruptible(&cl->rx_wait);
891 		else
892 			mei_cl_bus_rx_event(cl);
893 
894 	}
895 }
896 
897 
898 /**
899  * mei_cl_all_disconnect - disconnect forcefully all connected clients
900  *
901  * @dev - mei device
902  */
903 
904 void mei_cl_all_disconnect(struct mei_device *dev)
905 {
906 	struct mei_cl *cl, *next;
907 
908 	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
909 		cl->state = MEI_FILE_DISCONNECTED;
910 		cl->mei_flow_ctrl_creds = 0;
911 		cl->timer_count = 0;
912 	}
913 }
914 
915 
916 /**
917  * mei_cl_all_wakeup  - wake up all readers and writers they can be interrupted
918  *
919  * @dev  - mei device
920  */
921 void mei_cl_all_wakeup(struct mei_device *dev)
922 {
923 	struct mei_cl *cl, *next;
924 	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
925 		if (waitqueue_active(&cl->rx_wait)) {
926 			cl_dbg(dev, cl, "Waking up reading client!\n");
927 			wake_up_interruptible(&cl->rx_wait);
928 		}
929 		if (waitqueue_active(&cl->tx_wait)) {
930 			cl_dbg(dev, cl, "Waking up writing client!\n");
931 			wake_up_interruptible(&cl->tx_wait);
932 		}
933 	}
934 }
935 
936 /**
937  * mei_cl_all_write_clear - clear all pending writes
938 
939  * @dev - mei device
940  */
941 void mei_cl_all_write_clear(struct mei_device *dev)
942 {
943 	struct mei_cl_cb *cb, *next;
944 	struct list_head *list;
945 
946 	list = &dev->write_list.list;
947 	list_for_each_entry_safe(cb, next, list, list) {
948 		list_del(&cb->list);
949 		mei_io_cb_free(cb);
950 	}
951 
952 	list = &dev->write_waiting_list.list;
953 	list_for_each_entry_safe(cb, next, list, list) {
954 		list_del(&cb->list);
955 		mei_io_cb_free(cb);
956 	}
957 }
958 
959 
960