1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ISHTP client logic
4  *
5  * Copyright (c) 2003-2016, Intel Corporation.
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/sched.h>
10 #include <linux/wait.h>
11 #include <linux/delay.h>
12 #include <linux/dma-mapping.h>
13 #include "hbm.h"
14 #include "client.h"
15 
16 int ishtp_cl_get_tx_free_buffer_size(struct ishtp_cl *cl)
17 {
18 	unsigned long tx_free_flags;
19 	int size;
20 
21 	spin_lock_irqsave(&cl->tx_free_list_spinlock, tx_free_flags);
22 	size = cl->tx_ring_free_size * cl->device->fw_client->props.max_msg_length;
23 	spin_unlock_irqrestore(&cl->tx_free_list_spinlock, tx_free_flags);
24 
25 	return size;
26 }
27 EXPORT_SYMBOL(ishtp_cl_get_tx_free_buffer_size);
28 
29 int ishtp_cl_get_tx_free_rings(struct ishtp_cl *cl)
30 {
31 	return cl->tx_ring_free_size;
32 }
33 EXPORT_SYMBOL(ishtp_cl_get_tx_free_rings);
34 
35 /**
36  * ishtp_read_list_flush() - Flush read queue
37  * @cl: ishtp client instance
38  *
39  * Used to remove all entries from read queue for a client
40  */
41 static void ishtp_read_list_flush(struct ishtp_cl *cl)
42 {
43 	struct ishtp_cl_rb *rb;
44 	struct ishtp_cl_rb *next;
45 	unsigned long	flags;
46 
47 	spin_lock_irqsave(&cl->dev->read_list_spinlock, flags);
48 	list_for_each_entry_safe(rb, next, &cl->dev->read_list.list, list)
49 		if (rb->cl && ishtp_cl_cmp_id(cl, rb->cl)) {
50 			list_del(&rb->list);
51 			ishtp_io_rb_free(rb);
52 		}
53 	spin_unlock_irqrestore(&cl->dev->read_list_spinlock, flags);
54 }
55 
56 /**
57  * ishtp_cl_flush_queues() - Flush all queues for a client
58  * @cl: ishtp client instance
59  *
60  * Used to remove all queues for a client. This is called when a client device
61  * needs reset due to error, S3 resume or during module removal
62  *
63  * Return: 0 on success else -EINVAL if device is NULL
64  */
65 int ishtp_cl_flush_queues(struct ishtp_cl *cl)
66 {
67 	if (WARN_ON(!cl || !cl->dev))
68 		return -EINVAL;
69 
70 	ishtp_read_list_flush(cl);
71 
72 	return 0;
73 }
74 EXPORT_SYMBOL(ishtp_cl_flush_queues);
75 
76 /**
77  * ishtp_cl_init() - Initialize all fields of a client device
78  * @cl: ishtp client instance
79  * @dev: ishtp device
80  *
81  * Initializes a client device fields: Init spinlocks, init queues etc.
82  * This function is called during new client creation
83  */
84 static void ishtp_cl_init(struct ishtp_cl *cl, struct ishtp_device *dev)
85 {
86 	memset(cl, 0, sizeof(struct ishtp_cl));
87 	init_waitqueue_head(&cl->wait_ctrl_res);
88 	spin_lock_init(&cl->free_list_spinlock);
89 	spin_lock_init(&cl->in_process_spinlock);
90 	spin_lock_init(&cl->tx_list_spinlock);
91 	spin_lock_init(&cl->tx_free_list_spinlock);
92 	spin_lock_init(&cl->fc_spinlock);
93 	INIT_LIST_HEAD(&cl->link);
94 	cl->dev = dev;
95 
96 	INIT_LIST_HEAD(&cl->free_rb_list.list);
97 	INIT_LIST_HEAD(&cl->tx_list.list);
98 	INIT_LIST_HEAD(&cl->tx_free_list.list);
99 	INIT_LIST_HEAD(&cl->in_process_list.list);
100 
101 	cl->rx_ring_size = CL_DEF_RX_RING_SIZE;
102 	cl->tx_ring_size = CL_DEF_TX_RING_SIZE;
103 	cl->tx_ring_free_size = cl->tx_ring_size;
104 
105 	/* dma */
106 	cl->last_tx_path = CL_TX_PATH_IPC;
107 	cl->last_dma_acked = 1;
108 	cl->last_dma_addr = NULL;
109 	cl->last_ipc_acked = 1;
110 }
111 
112 /**
113  * ishtp_cl_allocate() - allocates client structure and sets it up.
114  * @dev: ishtp device
115  *
116  * Allocate memory for new client device and call to initialize each field.
117  *
118  * Return: The allocated client instance or NULL on failure
119  */
120 struct ishtp_cl *ishtp_cl_allocate(struct ishtp_cl_device *cl_device)
121 {
122 	struct ishtp_cl *cl;
123 
124 	cl = kmalloc(sizeof(struct ishtp_cl), GFP_KERNEL);
125 	if (!cl)
126 		return NULL;
127 
128 	ishtp_cl_init(cl, cl_device->ishtp_dev);
129 	return cl;
130 }
131 EXPORT_SYMBOL(ishtp_cl_allocate);
132 
133 /**
134  * ishtp_cl_free() - Frees a client device
135  * @cl: client device instance
136  *
137  * Frees a client device
138  */
139 void	ishtp_cl_free(struct ishtp_cl *cl)
140 {
141 	struct ishtp_device *dev;
142 	unsigned long flags;
143 
144 	if (!cl)
145 		return;
146 
147 	dev = cl->dev;
148 	if (!dev)
149 		return;
150 
151 	spin_lock_irqsave(&dev->cl_list_lock, flags);
152 	ishtp_cl_free_rx_ring(cl);
153 	ishtp_cl_free_tx_ring(cl);
154 	kfree(cl);
155 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
156 }
157 EXPORT_SYMBOL(ishtp_cl_free);
158 
159 /**
160  * ishtp_cl_link() - Reserve a host id and link the client instance
161  * @cl: client device instance
162  *
163  * This allocates a single bit in the hostmap. This function will make sure
164  * that not many client sessions are opened at the same time. Once allocated
165  * the client device instance is added to the ishtp device in the current
166  * client list
167  *
168  * Return: 0 or error code on failure
169  */
170 int ishtp_cl_link(struct ishtp_cl *cl)
171 {
172 	struct ishtp_device *dev;
173 	unsigned long flags, flags_cl;
174 	int id, ret = 0;
175 
176 	if (WARN_ON(!cl || !cl->dev))
177 		return -EINVAL;
178 
179 	dev = cl->dev;
180 
181 	spin_lock_irqsave(&dev->device_lock, flags);
182 
183 	if (dev->open_handle_count >= ISHTP_MAX_OPEN_HANDLE_COUNT) {
184 		ret = -EMFILE;
185 		goto unlock_dev;
186 	}
187 
188 	id = find_first_zero_bit(dev->host_clients_map, ISHTP_CLIENTS_MAX);
189 
190 	if (id >= ISHTP_CLIENTS_MAX) {
191 		spin_unlock_irqrestore(&dev->device_lock, flags);
192 		dev_err(&cl->device->dev, "id exceeded %d", ISHTP_CLIENTS_MAX);
193 		return -ENOENT;
194 	}
195 
196 	dev->open_handle_count++;
197 	cl->host_client_id = id;
198 	spin_lock_irqsave(&dev->cl_list_lock, flags_cl);
199 	if (dev->dev_state != ISHTP_DEV_ENABLED) {
200 		ret = -ENODEV;
201 		goto unlock_cl;
202 	}
203 	list_add_tail(&cl->link, &dev->cl_list);
204 	set_bit(id, dev->host_clients_map);
205 	cl->state = ISHTP_CL_INITIALIZING;
206 
207 unlock_cl:
208 	spin_unlock_irqrestore(&dev->cl_list_lock, flags_cl);
209 unlock_dev:
210 	spin_unlock_irqrestore(&dev->device_lock, flags);
211 	return ret;
212 }
213 EXPORT_SYMBOL(ishtp_cl_link);
214 
215 /**
216  * ishtp_cl_unlink() - remove fw_cl from the client device list
217  * @cl: client device instance
218  *
219  * Remove a previously linked device to a ishtp device
220  */
221 void ishtp_cl_unlink(struct ishtp_cl *cl)
222 {
223 	struct ishtp_device *dev;
224 	struct ishtp_cl *pos;
225 	unsigned long	flags;
226 
227 	/* don't shout on error exit path */
228 	if (!cl || !cl->dev)
229 		return;
230 
231 	dev = cl->dev;
232 
233 	spin_lock_irqsave(&dev->device_lock, flags);
234 	if (dev->open_handle_count > 0) {
235 		clear_bit(cl->host_client_id, dev->host_clients_map);
236 		dev->open_handle_count--;
237 	}
238 	spin_unlock_irqrestore(&dev->device_lock, flags);
239 
240 	/*
241 	 * This checks that 'cl' is actually linked into device's structure,
242 	 * before attempting 'list_del'
243 	 */
244 	spin_lock_irqsave(&dev->cl_list_lock, flags);
245 	list_for_each_entry(pos, &dev->cl_list, link)
246 		if (cl->host_client_id == pos->host_client_id) {
247 			list_del_init(&pos->link);
248 			break;
249 		}
250 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
251 }
252 EXPORT_SYMBOL(ishtp_cl_unlink);
253 
254 /**
255  * ishtp_cl_disconnect() - Send disconnect request to firmware
256  * @cl: client device instance
257  *
258  * Send a disconnect request for a client to firmware.
259  *
260  * Return: 0 if successful disconnect response from the firmware or error
261  * code on failure
262  */
263 int ishtp_cl_disconnect(struct ishtp_cl *cl)
264 {
265 	struct ishtp_device *dev;
266 	int err;
267 
268 	if (WARN_ON(!cl || !cl->dev))
269 		return -ENODEV;
270 
271 	dev = cl->dev;
272 
273 	dev->print_log(dev, "%s() state %d\n", __func__, cl->state);
274 
275 	if (cl->state != ISHTP_CL_DISCONNECTING) {
276 		dev->print_log(dev, "%s() Disconnect in progress\n", __func__);
277 		return 0;
278 	}
279 
280 	if (ishtp_hbm_cl_disconnect_req(dev, cl)) {
281 		dev->print_log(dev, "%s() Failed to disconnect\n", __func__);
282 		dev_err(&cl->device->dev, "failed to disconnect.\n");
283 		return -ENODEV;
284 	}
285 
286 	err = wait_event_interruptible_timeout(cl->wait_ctrl_res,
287 			(dev->dev_state != ISHTP_DEV_ENABLED ||
288 			cl->state == ISHTP_CL_DISCONNECTED),
289 			ishtp_secs_to_jiffies(ISHTP_CL_CONNECT_TIMEOUT));
290 
291 	/*
292 	 * If FW reset arrived, this will happen. Don't check cl->,
293 	 * as 'cl' may be freed already
294 	 */
295 	if (dev->dev_state != ISHTP_DEV_ENABLED) {
296 		dev->print_log(dev, "%s() dev_state != ISHTP_DEV_ENABLED\n",
297 			       __func__);
298 		return -ENODEV;
299 	}
300 
301 	if (cl->state == ISHTP_CL_DISCONNECTED) {
302 		dev->print_log(dev, "%s() successful\n", __func__);
303 		return 0;
304 	}
305 
306 	return -ENODEV;
307 }
308 EXPORT_SYMBOL(ishtp_cl_disconnect);
309 
310 /**
311  * ishtp_cl_is_other_connecting() - Check other client is connecting
312  * @cl: client device instance
313  *
314  * Checks if other client with the same fw client id is connecting
315  *
316  * Return: true if other client is connected else false
317  */
318 static bool ishtp_cl_is_other_connecting(struct ishtp_cl *cl)
319 {
320 	struct ishtp_device *dev;
321 	struct ishtp_cl *pos;
322 	unsigned long	flags;
323 
324 	if (WARN_ON(!cl || !cl->dev))
325 		return false;
326 
327 	dev = cl->dev;
328 	spin_lock_irqsave(&dev->cl_list_lock, flags);
329 	list_for_each_entry(pos, &dev->cl_list, link) {
330 		if ((pos->state == ISHTP_CL_CONNECTING) && (pos != cl) &&
331 				cl->fw_client_id == pos->fw_client_id) {
332 			spin_unlock_irqrestore(&dev->cl_list_lock, flags);
333 			return true;
334 		}
335 	}
336 	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
337 
338 	return false;
339 }
340 
341 /**
342  * ishtp_cl_connect() - Send connect request to firmware
343  * @cl: client device instance
344  *
345  * Send a connect request for a client to firmware. If successful it will
346  * RX and TX ring buffers
347  *
348  * Return: 0 if successful connect response from the firmware and able
349  * to bind and allocate ring buffers or error code on failure
350  */
351 int ishtp_cl_connect(struct ishtp_cl *cl)
352 {
353 	struct ishtp_device *dev;
354 	int rets;
355 
356 	if (WARN_ON(!cl || !cl->dev))
357 		return -ENODEV;
358 
359 	dev = cl->dev;
360 
361 	dev->print_log(dev, "%s() current_state = %d\n", __func__, cl->state);
362 
363 	if (ishtp_cl_is_other_connecting(cl)) {
364 		dev->print_log(dev, "%s() Busy\n", __func__);
365 		return	-EBUSY;
366 	}
367 
368 	if (ishtp_hbm_cl_connect_req(dev, cl)) {
369 		dev->print_log(dev, "%s() HBM connect req fail\n", __func__);
370 		return -ENODEV;
371 	}
372 
373 	rets = wait_event_interruptible_timeout(cl->wait_ctrl_res,
374 				(dev->dev_state == ISHTP_DEV_ENABLED &&
375 				(cl->state == ISHTP_CL_CONNECTED ||
376 				 cl->state == ISHTP_CL_DISCONNECTED)),
377 				ishtp_secs_to_jiffies(
378 					ISHTP_CL_CONNECT_TIMEOUT));
379 	/*
380 	 * If FW reset arrived, this will happen. Don't check cl->,
381 	 * as 'cl' may be freed already
382 	 */
383 	if (dev->dev_state != ISHTP_DEV_ENABLED) {
384 		dev->print_log(dev, "%s() dev_state != ISHTP_DEV_ENABLED\n",
385 			       __func__);
386 		return -EFAULT;
387 	}
388 
389 	if (cl->state != ISHTP_CL_CONNECTED) {
390 		dev->print_log(dev, "%s() state != ISHTP_CL_CONNECTED\n",
391 			       __func__);
392 		return -EFAULT;
393 	}
394 
395 	rets = cl->status;
396 	if (rets) {
397 		dev->print_log(dev, "%s() Invalid status\n", __func__);
398 		return rets;
399 	}
400 
401 	rets = ishtp_cl_device_bind(cl);
402 	if (rets) {
403 		dev->print_log(dev, "%s() Bind error\n", __func__);
404 		ishtp_cl_disconnect(cl);
405 		return rets;
406 	}
407 
408 	rets = ishtp_cl_alloc_rx_ring(cl);
409 	if (rets) {
410 		dev->print_log(dev, "%s() Alloc RX ring failed\n", __func__);
411 		/* if failed allocation, disconnect */
412 		ishtp_cl_disconnect(cl);
413 		return rets;
414 	}
415 
416 	rets = ishtp_cl_alloc_tx_ring(cl);
417 	if (rets) {
418 		dev->print_log(dev, "%s() Alloc TX ring failed\n", __func__);
419 		/* if failed allocation, disconnect */
420 		ishtp_cl_free_rx_ring(cl);
421 		ishtp_cl_disconnect(cl);
422 		return rets;
423 	}
424 
425 	/* Upon successful connection and allocation, emit flow-control */
426 	rets = ishtp_cl_read_start(cl);
427 
428 	dev->print_log(dev, "%s() successful\n", __func__);
429 
430 	return rets;
431 }
432 EXPORT_SYMBOL(ishtp_cl_connect);
433 
434 /**
435  * ishtp_cl_read_start() - Prepare to read client message
436  * @cl: client device instance
437  *
438  * Get a free buffer from pool of free read buffers and add to read buffer
439  * pool to add contents. Send a flow control request to firmware to be able
440  * send next message.
441  *
442  * Return: 0 if successful or error code on failure
443  */
444 int ishtp_cl_read_start(struct ishtp_cl *cl)
445 {
446 	struct ishtp_device *dev;
447 	struct ishtp_cl_rb *rb;
448 	int rets;
449 	int i;
450 	unsigned long	flags;
451 	unsigned long	dev_flags;
452 
453 	if (WARN_ON(!cl || !cl->dev))
454 		return -ENODEV;
455 
456 	dev = cl->dev;
457 
458 	if (cl->state != ISHTP_CL_CONNECTED)
459 		return -ENODEV;
460 
461 	if (dev->dev_state != ISHTP_DEV_ENABLED)
462 		return -ENODEV;
463 
464 	i = ishtp_fw_cl_by_id(dev, cl->fw_client_id);
465 	if (i < 0) {
466 		dev_err(&cl->device->dev, "no such fw client %d\n",
467 			cl->fw_client_id);
468 		return -ENODEV;
469 	}
470 
471 	/* The current rb is the head of the free rb list */
472 	spin_lock_irqsave(&cl->free_list_spinlock, flags);
473 	if (list_empty(&cl->free_rb_list.list)) {
474 		dev_warn(&cl->device->dev,
475 			 "[ishtp-ish] Rx buffers pool is empty\n");
476 		rets = -ENOMEM;
477 		rb = NULL;
478 		spin_unlock_irqrestore(&cl->free_list_spinlock, flags);
479 		goto out;
480 	}
481 	rb = list_entry(cl->free_rb_list.list.next, struct ishtp_cl_rb, list);
482 	list_del_init(&rb->list);
483 	spin_unlock_irqrestore(&cl->free_list_spinlock, flags);
484 
485 	rb->cl = cl;
486 	rb->buf_idx = 0;
487 
488 	INIT_LIST_HEAD(&rb->list);
489 	rets = 0;
490 
491 	/*
492 	 * This must be BEFORE sending flow control -
493 	 * response in ISR may come too fast...
494 	 */
495 	spin_lock_irqsave(&dev->read_list_spinlock, dev_flags);
496 	list_add_tail(&rb->list, &dev->read_list.list);
497 	spin_unlock_irqrestore(&dev->read_list_spinlock, dev_flags);
498 	if (ishtp_hbm_cl_flow_control_req(dev, cl)) {
499 		rets = -ENODEV;
500 		goto out;
501 	}
502 out:
503 	/* if ishtp_hbm_cl_flow_control_req failed, return rb to free list */
504 	if (rets && rb) {
505 		spin_lock_irqsave(&dev->read_list_spinlock, dev_flags);
506 		list_del(&rb->list);
507 		spin_unlock_irqrestore(&dev->read_list_spinlock, dev_flags);
508 
509 		spin_lock_irqsave(&cl->free_list_spinlock, flags);
510 		list_add_tail(&rb->list, &cl->free_rb_list.list);
511 		spin_unlock_irqrestore(&cl->free_list_spinlock, flags);
512 	}
513 	return rets;
514 }
515 
516 /**
517  * ishtp_cl_send() - Send a message to firmware
518  * @cl: client device instance
519  * @buf: message buffer
520  * @length: length of message
521  *
522  * If the client is correct state to send message, this function gets a buffer
523  * from tx ring buffers, copy the message data and call to send the message
524  * using ishtp_cl_send_msg()
525  *
526  * Return: 0 if successful or error code on failure
527  */
528 int ishtp_cl_send(struct ishtp_cl *cl, uint8_t *buf, size_t length)
529 {
530 	struct ishtp_device	*dev;
531 	int	id;
532 	struct ishtp_cl_tx_ring	*cl_msg;
533 	int	have_msg_to_send = 0;
534 	unsigned long	tx_flags, tx_free_flags;
535 
536 	if (WARN_ON(!cl || !cl->dev))
537 		return -ENODEV;
538 
539 	dev = cl->dev;
540 
541 	if (cl->state != ISHTP_CL_CONNECTED) {
542 		++cl->err_send_msg;
543 		return -EPIPE;
544 	}
545 
546 	if (dev->dev_state != ISHTP_DEV_ENABLED) {
547 		++cl->err_send_msg;
548 		return -ENODEV;
549 	}
550 
551 	/* Check if we have fw client device */
552 	id = ishtp_fw_cl_by_id(dev, cl->fw_client_id);
553 	if (id < 0) {
554 		++cl->err_send_msg;
555 		return -ENOENT;
556 	}
557 
558 	if (length > dev->fw_clients[id].props.max_msg_length) {
559 		++cl->err_send_msg;
560 		return -EMSGSIZE;
561 	}
562 
563 	/* No free bufs */
564 	spin_lock_irqsave(&cl->tx_free_list_spinlock, tx_free_flags);
565 	if (list_empty(&cl->tx_free_list.list)) {
566 		spin_unlock_irqrestore(&cl->tx_free_list_spinlock,
567 			tx_free_flags);
568 		++cl->err_send_msg;
569 		return	-ENOMEM;
570 	}
571 
572 	cl_msg = list_first_entry(&cl->tx_free_list.list,
573 		struct ishtp_cl_tx_ring, list);
574 	if (!cl_msg->send_buf.data) {
575 		spin_unlock_irqrestore(&cl->tx_free_list_spinlock,
576 			tx_free_flags);
577 		return	-EIO;
578 		/* Should not happen, as free list is pre-allocated */
579 	}
580 	/*
581 	 * This is safe, as 'length' is already checked for not exceeding
582 	 * max ISHTP message size per client
583 	 */
584 	list_del_init(&cl_msg->list);
585 	--cl->tx_ring_free_size;
586 
587 	spin_unlock_irqrestore(&cl->tx_free_list_spinlock, tx_free_flags);
588 	memcpy(cl_msg->send_buf.data, buf, length);
589 	cl_msg->send_buf.size = length;
590 	spin_lock_irqsave(&cl->tx_list_spinlock, tx_flags);
591 	have_msg_to_send = !list_empty(&cl->tx_list.list);
592 	list_add_tail(&cl_msg->list, &cl->tx_list.list);
593 	spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
594 
595 	if (!have_msg_to_send && cl->ishtp_flow_ctrl_creds > 0)
596 		ishtp_cl_send_msg(dev, cl);
597 
598 	return	0;
599 }
600 EXPORT_SYMBOL(ishtp_cl_send);
601 
602 /**
603  * ishtp_cl_read_complete() - read complete
604  * @rb: Pointer to client request block
605  *
606  * If the message is completely received call ishtp_cl_bus_rx_event()
607  * to process message
608  */
609 static void ishtp_cl_read_complete(struct ishtp_cl_rb *rb)
610 {
611 	unsigned long	flags;
612 	int	schedule_work_flag = 0;
613 	struct ishtp_cl	*cl = rb->cl;
614 
615 	spin_lock_irqsave(&cl->in_process_spinlock, flags);
616 	/*
617 	 * if in-process list is empty, then need to schedule
618 	 * the processing thread
619 	 */
620 	schedule_work_flag = list_empty(&cl->in_process_list.list);
621 	list_add_tail(&rb->list, &cl->in_process_list.list);
622 	spin_unlock_irqrestore(&cl->in_process_spinlock, flags);
623 
624 	if (schedule_work_flag)
625 		ishtp_cl_bus_rx_event(cl->device);
626 }
627 
628 /**
629  * ipc_tx_callback() - IPC tx callback function
630  * @prm: Pointer to client device instance
631  *
632  * Send message over IPC either first time or on callback on previous message
633  * completion
634  */
635 static void ipc_tx_callback(void *prm)
636 {
637 	struct ishtp_cl	*cl = prm;
638 	struct ishtp_cl_tx_ring	*cl_msg;
639 	size_t	rem;
640 	struct ishtp_device	*dev = (cl ? cl->dev : NULL);
641 	struct ishtp_msg_hdr	ishtp_hdr;
642 	unsigned long	tx_flags, tx_free_flags;
643 	unsigned char	*pmsg;
644 
645 	if (!dev)
646 		return;
647 
648 	/*
649 	 * Other conditions if some critical error has
650 	 * occurred before this callback is called
651 	 */
652 	if (dev->dev_state != ISHTP_DEV_ENABLED)
653 		return;
654 
655 	if (cl->state != ISHTP_CL_CONNECTED)
656 		return;
657 
658 	spin_lock_irqsave(&cl->tx_list_spinlock, tx_flags);
659 	if (list_empty(&cl->tx_list.list)) {
660 		spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
661 		return;
662 	}
663 
664 	if (cl->ishtp_flow_ctrl_creds != 1 && !cl->sending) {
665 		spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
666 		return;
667 	}
668 
669 	if (!cl->sending) {
670 		--cl->ishtp_flow_ctrl_creds;
671 		cl->last_ipc_acked = 0;
672 		cl->last_tx_path = CL_TX_PATH_IPC;
673 		cl->sending = 1;
674 	}
675 
676 	cl_msg = list_entry(cl->tx_list.list.next, struct ishtp_cl_tx_ring,
677 			    list);
678 	rem = cl_msg->send_buf.size - cl->tx_offs;
679 
680 	ishtp_hdr.host_addr = cl->host_client_id;
681 	ishtp_hdr.fw_addr = cl->fw_client_id;
682 	ishtp_hdr.reserved = 0;
683 	pmsg = cl_msg->send_buf.data + cl->tx_offs;
684 
685 	if (rem <= dev->mtu) {
686 		ishtp_hdr.length = rem;
687 		ishtp_hdr.msg_complete = 1;
688 		cl->sending = 0;
689 		list_del_init(&cl_msg->list);	/* Must be before write */
690 		spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
691 		/* Submit to IPC queue with no callback */
692 		ishtp_write_message(dev, &ishtp_hdr, pmsg);
693 		spin_lock_irqsave(&cl->tx_free_list_spinlock, tx_free_flags);
694 		list_add_tail(&cl_msg->list, &cl->tx_free_list.list);
695 		++cl->tx_ring_free_size;
696 		spin_unlock_irqrestore(&cl->tx_free_list_spinlock,
697 			tx_free_flags);
698 	} else {
699 		/* Send IPC fragment */
700 		spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
701 		cl->tx_offs += dev->mtu;
702 		ishtp_hdr.length = dev->mtu;
703 		ishtp_hdr.msg_complete = 0;
704 		ishtp_send_msg(dev, &ishtp_hdr, pmsg, ipc_tx_callback, cl);
705 	}
706 }
707 
708 /**
709  * ishtp_cl_send_msg_ipc() -Send message using IPC
710  * @dev: ISHTP device instance
711  * @cl: Pointer to client device instance
712  *
713  * Send message over IPC not using DMA
714  */
715 static void ishtp_cl_send_msg_ipc(struct ishtp_device *dev,
716 				  struct ishtp_cl *cl)
717 {
718 	/* If last DMA message wasn't acked yet, leave this one in Tx queue */
719 	if (cl->last_tx_path == CL_TX_PATH_DMA && cl->last_dma_acked == 0)
720 		return;
721 
722 	cl->tx_offs = 0;
723 	ipc_tx_callback(cl);
724 	++cl->send_msg_cnt_ipc;
725 }
726 
727 /**
728  * ishtp_cl_send_msg_dma() -Send message using DMA
729  * @dev: ISHTP device instance
730  * @cl: Pointer to client device instance
731  *
732  * Send message using DMA
733  */
734 static void ishtp_cl_send_msg_dma(struct ishtp_device *dev,
735 	struct ishtp_cl *cl)
736 {
737 	struct ishtp_msg_hdr	hdr;
738 	struct dma_xfer_hbm	dma_xfer;
739 	unsigned char	*msg_addr;
740 	int off;
741 	struct ishtp_cl_tx_ring	*cl_msg;
742 	unsigned long tx_flags, tx_free_flags;
743 
744 	/* If last IPC message wasn't acked yet, leave this one in Tx queue */
745 	if (cl->last_tx_path == CL_TX_PATH_IPC && cl->last_ipc_acked == 0)
746 		return;
747 
748 	spin_lock_irqsave(&cl->tx_list_spinlock, tx_flags);
749 	if (list_empty(&cl->tx_list.list)) {
750 		spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
751 		return;
752 	}
753 
754 	cl_msg = list_entry(cl->tx_list.list.next, struct ishtp_cl_tx_ring,
755 		list);
756 
757 	msg_addr = ishtp_cl_get_dma_send_buf(dev, cl_msg->send_buf.size);
758 	if (!msg_addr) {
759 		spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
760 		if (dev->transfer_path == CL_TX_PATH_DEFAULT)
761 			ishtp_cl_send_msg_ipc(dev, cl);
762 		return;
763 	}
764 
765 	list_del_init(&cl_msg->list);	/* Must be before write */
766 	spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
767 
768 	--cl->ishtp_flow_ctrl_creds;
769 	cl->last_dma_acked = 0;
770 	cl->last_dma_addr = msg_addr;
771 	cl->last_tx_path = CL_TX_PATH_DMA;
772 
773 	/* write msg to dma buf */
774 	memcpy(msg_addr, cl_msg->send_buf.data, cl_msg->send_buf.size);
775 
776 	/* send dma_xfer hbm msg */
777 	off = msg_addr - (unsigned char *)dev->ishtp_host_dma_tx_buf;
778 	ishtp_hbm_hdr(&hdr, sizeof(struct dma_xfer_hbm));
779 	dma_xfer.hbm = DMA_XFER;
780 	dma_xfer.fw_client_id = cl->fw_client_id;
781 	dma_xfer.host_client_id = cl->host_client_id;
782 	dma_xfer.reserved = 0;
783 	dma_xfer.msg_addr = dev->ishtp_host_dma_tx_buf_phys + off;
784 	dma_xfer.msg_length = cl_msg->send_buf.size;
785 	dma_xfer.reserved2 = 0;
786 	ishtp_write_message(dev, &hdr, (unsigned char *)&dma_xfer);
787 	spin_lock_irqsave(&cl->tx_free_list_spinlock, tx_free_flags);
788 	list_add_tail(&cl_msg->list, &cl->tx_free_list.list);
789 	++cl->tx_ring_free_size;
790 	spin_unlock_irqrestore(&cl->tx_free_list_spinlock, tx_free_flags);
791 	++cl->send_msg_cnt_dma;
792 }
793 
794 /**
795  * ishtp_cl_send_msg() -Send message using DMA or IPC
796  * @dev: ISHTP device instance
797  * @cl: Pointer to client device instance
798  *
799  * Send message using DMA or IPC based on transfer_path
800  */
801 void ishtp_cl_send_msg(struct ishtp_device *dev, struct ishtp_cl *cl)
802 {
803 	if (dev->transfer_path == CL_TX_PATH_DMA)
804 		ishtp_cl_send_msg_dma(dev, cl);
805 	else
806 		ishtp_cl_send_msg_ipc(dev, cl);
807 }
808 
809 /**
810  * recv_ishtp_cl_msg() -Receive client message
811  * @dev: ISHTP device instance
812  * @ishtp_hdr: Pointer to message header
813  *
814  * Receive and dispatch ISHTP client messages. This function executes in ISR
815  * or work queue context
816  */
817 void recv_ishtp_cl_msg(struct ishtp_device *dev,
818 		       struct ishtp_msg_hdr *ishtp_hdr)
819 {
820 	struct ishtp_cl *cl;
821 	struct ishtp_cl_rb *rb;
822 	struct ishtp_cl_rb *new_rb;
823 	unsigned char *buffer = NULL;
824 	struct ishtp_cl_rb *complete_rb = NULL;
825 	unsigned long	flags;
826 	int	rb_count;
827 
828 	if (ishtp_hdr->reserved) {
829 		dev_err(dev->devc, "corrupted message header.\n");
830 		goto	eoi;
831 	}
832 
833 	if (ishtp_hdr->length > IPC_PAYLOAD_SIZE) {
834 		dev_err(dev->devc,
835 			"ISHTP message length in hdr exceeds IPC MTU\n");
836 		goto	eoi;
837 	}
838 
839 	spin_lock_irqsave(&dev->read_list_spinlock, flags);
840 	rb_count = -1;
841 	list_for_each_entry(rb, &dev->read_list.list, list) {
842 		++rb_count;
843 		cl = rb->cl;
844 		if (!cl || !(cl->host_client_id == ishtp_hdr->host_addr &&
845 				cl->fw_client_id == ishtp_hdr->fw_addr) ||
846 				!(cl->state == ISHTP_CL_CONNECTED))
847 			continue;
848 
849 		 /* If no Rx buffer is allocated, disband the rb */
850 		if (rb->buffer.size == 0 || rb->buffer.data == NULL) {
851 			spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
852 			dev_err(&cl->device->dev,
853 				"Rx buffer is not allocated.\n");
854 			list_del(&rb->list);
855 			ishtp_io_rb_free(rb);
856 			cl->status = -ENOMEM;
857 			goto	eoi;
858 		}
859 
860 		/*
861 		 * If message buffer overflown (exceeds max. client msg
862 		 * size, drop message and return to free buffer.
863 		 * Do we need to disconnect such a client? (We don't send
864 		 * back FC, so communication will be stuck anyway)
865 		 */
866 		if (rb->buffer.size < ishtp_hdr->length + rb->buf_idx) {
867 			spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
868 			dev_err(&cl->device->dev,
869 				"message overflow. size %d len %d idx %ld\n",
870 				rb->buffer.size, ishtp_hdr->length,
871 				rb->buf_idx);
872 			list_del(&rb->list);
873 			ishtp_cl_io_rb_recycle(rb);
874 			cl->status = -EIO;
875 			goto	eoi;
876 		}
877 
878 		buffer = rb->buffer.data + rb->buf_idx;
879 		dev->ops->ishtp_read(dev, buffer, ishtp_hdr->length);
880 
881 		rb->buf_idx += ishtp_hdr->length;
882 		if (ishtp_hdr->msg_complete) {
883 			/* Last fragment in message - it's complete */
884 			cl->status = 0;
885 			list_del(&rb->list);
886 			complete_rb = rb;
887 
888 			--cl->out_flow_ctrl_creds;
889 			/*
890 			 * the whole msg arrived, send a new FC, and add a new
891 			 * rb buffer for the next coming msg
892 			 */
893 			spin_lock(&cl->free_list_spinlock);
894 
895 			if (!list_empty(&cl->free_rb_list.list)) {
896 				new_rb = list_entry(cl->free_rb_list.list.next,
897 					struct ishtp_cl_rb, list);
898 				list_del_init(&new_rb->list);
899 				spin_unlock(&cl->free_list_spinlock);
900 				new_rb->cl = cl;
901 				new_rb->buf_idx = 0;
902 				INIT_LIST_HEAD(&new_rb->list);
903 				list_add_tail(&new_rb->list,
904 					&dev->read_list.list);
905 
906 				ishtp_hbm_cl_flow_control_req(dev, cl);
907 			} else {
908 				spin_unlock(&cl->free_list_spinlock);
909 			}
910 		}
911 		/* One more fragment in message (even if this was last) */
912 		++cl->recv_msg_num_frags;
913 
914 		/*
915 		 * We can safely break here (and in BH too),
916 		 * a single input message can go only to a single request!
917 		 */
918 		break;
919 	}
920 
921 	spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
922 	/* If it's nobody's message, just read and discard it */
923 	if (!buffer) {
924 		uint8_t	rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
925 
926 		dev_err(dev->devc, "Dropped Rx msg - no request\n");
927 		dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
928 		goto	eoi;
929 	}
930 
931 	if (complete_rb) {
932 		cl = complete_rb->cl;
933 		cl->ts_rx = ktime_get();
934 		++cl->recv_msg_cnt_ipc;
935 		ishtp_cl_read_complete(complete_rb);
936 	}
937 eoi:
938 	return;
939 }
940 
941 /**
942  * recv_ishtp_cl_msg_dma() -Receive client message
943  * @dev: ISHTP device instance
944  * @msg: message pointer
945  * @hbm: hbm buffer
946  *
947  * Receive and dispatch ISHTP client messages using DMA. This function executes
948  * in ISR or work queue context
949  */
950 void recv_ishtp_cl_msg_dma(struct ishtp_device *dev, void *msg,
951 			   struct dma_xfer_hbm *hbm)
952 {
953 	struct ishtp_cl *cl;
954 	struct ishtp_cl_rb *rb;
955 	struct ishtp_cl_rb *new_rb;
956 	unsigned char *buffer = NULL;
957 	struct ishtp_cl_rb *complete_rb = NULL;
958 	unsigned long	flags;
959 
960 	spin_lock_irqsave(&dev->read_list_spinlock, flags);
961 
962 	list_for_each_entry(rb, &dev->read_list.list, list) {
963 		cl = rb->cl;
964 		if (!cl || !(cl->host_client_id == hbm->host_client_id &&
965 				cl->fw_client_id == hbm->fw_client_id) ||
966 				!(cl->state == ISHTP_CL_CONNECTED))
967 			continue;
968 
969 		/*
970 		 * If no Rx buffer is allocated, disband the rb
971 		 */
972 		if (rb->buffer.size == 0 || rb->buffer.data == NULL) {
973 			spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
974 			dev_err(&cl->device->dev,
975 				"response buffer is not allocated.\n");
976 			list_del(&rb->list);
977 			ishtp_io_rb_free(rb);
978 			cl->status = -ENOMEM;
979 			goto	eoi;
980 		}
981 
982 		/*
983 		 * If message buffer overflown (exceeds max. client msg
984 		 * size, drop message and return to free buffer.
985 		 * Do we need to disconnect such a client? (We don't send
986 		 * back FC, so communication will be stuck anyway)
987 		 */
988 		if (rb->buffer.size < hbm->msg_length) {
989 			spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
990 			dev_err(&cl->device->dev,
991 				"message overflow. size %d len %d idx %ld\n",
992 				rb->buffer.size, hbm->msg_length, rb->buf_idx);
993 			list_del(&rb->list);
994 			ishtp_cl_io_rb_recycle(rb);
995 			cl->status = -EIO;
996 			goto	eoi;
997 		}
998 
999 		buffer = rb->buffer.data;
1000 		memcpy(buffer, msg, hbm->msg_length);
1001 		rb->buf_idx = hbm->msg_length;
1002 
1003 		/* Last fragment in message - it's complete */
1004 		cl->status = 0;
1005 		list_del(&rb->list);
1006 		complete_rb = rb;
1007 
1008 		--cl->out_flow_ctrl_creds;
1009 		/*
1010 		 * the whole msg arrived, send a new FC, and add a new
1011 		 * rb buffer for the next coming msg
1012 		 */
1013 		spin_lock(&cl->free_list_spinlock);
1014 
1015 		if (!list_empty(&cl->free_rb_list.list)) {
1016 			new_rb = list_entry(cl->free_rb_list.list.next,
1017 				struct ishtp_cl_rb, list);
1018 			list_del_init(&new_rb->list);
1019 			spin_unlock(&cl->free_list_spinlock);
1020 			new_rb->cl = cl;
1021 			new_rb->buf_idx = 0;
1022 			INIT_LIST_HEAD(&new_rb->list);
1023 			list_add_tail(&new_rb->list,
1024 				&dev->read_list.list);
1025 
1026 			ishtp_hbm_cl_flow_control_req(dev, cl);
1027 		} else {
1028 			spin_unlock(&cl->free_list_spinlock);
1029 		}
1030 
1031 		/* One more fragment in message (this is always last) */
1032 		++cl->recv_msg_num_frags;
1033 
1034 		/*
1035 		 * We can safely break here (and in BH too),
1036 		 * a single input message can go only to a single request!
1037 		 */
1038 		break;
1039 	}
1040 
1041 	spin_unlock_irqrestore(&dev->read_list_spinlock, flags);
1042 	/* If it's nobody's message, just read and discard it */
1043 	if (!buffer) {
1044 		dev_err(dev->devc, "Dropped Rx (DMA) msg - no request\n");
1045 		goto	eoi;
1046 	}
1047 
1048 	if (complete_rb) {
1049 		cl = complete_rb->cl;
1050 		cl->ts_rx = ktime_get();
1051 		++cl->recv_msg_cnt_dma;
1052 		ishtp_cl_read_complete(complete_rb);
1053 	}
1054 eoi:
1055 	return;
1056 }
1057 
1058 void *ishtp_get_client_data(struct ishtp_cl *cl)
1059 {
1060 	return cl->client_data;
1061 }
1062 EXPORT_SYMBOL(ishtp_get_client_data);
1063 
1064 void ishtp_set_client_data(struct ishtp_cl *cl, void *data)
1065 {
1066 	cl->client_data = data;
1067 }
1068 EXPORT_SYMBOL(ishtp_set_client_data);
1069 
1070 struct ishtp_device *ishtp_get_ishtp_device(struct ishtp_cl *cl)
1071 {
1072 	return cl->dev;
1073 }
1074 EXPORT_SYMBOL(ishtp_get_ishtp_device);
1075 
1076 void ishtp_set_tx_ring_size(struct ishtp_cl *cl, int size)
1077 {
1078 	cl->tx_ring_size = size;
1079 }
1080 EXPORT_SYMBOL(ishtp_set_tx_ring_size);
1081 
1082 void ishtp_set_rx_ring_size(struct ishtp_cl *cl, int size)
1083 {
1084 	cl->rx_ring_size = size;
1085 }
1086 EXPORT_SYMBOL(ishtp_set_rx_ring_size);
1087 
1088 void ishtp_set_connection_state(struct ishtp_cl *cl, int state)
1089 {
1090 	cl->state = state;
1091 }
1092 EXPORT_SYMBOL(ishtp_set_connection_state);
1093 
1094 void ishtp_cl_set_fw_client_id(struct ishtp_cl *cl, int fw_client_id)
1095 {
1096 	cl->fw_client_id = fw_client_id;
1097 }
1098 EXPORT_SYMBOL(ishtp_cl_set_fw_client_id);
1099