xref: /openbmc/linux/drivers/net/wireless/ath/ath10k/htc.c (revision afb46f79)
1 /*
2  * Copyright (c) 2005-2011 Atheros Communications Inc.
3  * Copyright (c) 2011-2013 Qualcomm Atheros, Inc.
4  *
5  * Permission to use, copy, modify, and/or distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include "core.h"
19 #include "hif.h"
20 #include "debug.h"
21 
22 /********/
23 /* Send */
24 /********/
25 
26 static inline void ath10k_htc_send_complete_check(struct ath10k_htc_ep *ep,
27 						  int force)
28 {
29 	/*
30 	 * Check whether HIF has any prior sends that have finished,
31 	 * have not had the post-processing done.
32 	 */
33 	ath10k_hif_send_complete_check(ep->htc->ar, ep->ul_pipe_id, force);
34 }
35 
36 static void ath10k_htc_control_tx_complete(struct ath10k *ar,
37 					   struct sk_buff *skb)
38 {
39 	kfree_skb(skb);
40 }
41 
42 static struct sk_buff *ath10k_htc_build_tx_ctrl_skb(void *ar)
43 {
44 	struct sk_buff *skb;
45 	struct ath10k_skb_cb *skb_cb;
46 
47 	skb = dev_alloc_skb(ATH10K_HTC_CONTROL_BUFFER_SIZE);
48 	if (!skb) {
49 		ath10k_warn("Unable to allocate ctrl skb\n");
50 		return NULL;
51 	}
52 
53 	skb_reserve(skb, 20); /* FIXME: why 20 bytes? */
54 	WARN_ONCE((unsigned long)skb->data & 3, "unaligned skb");
55 
56 	skb_cb = ATH10K_SKB_CB(skb);
57 	memset(skb_cb, 0, sizeof(*skb_cb));
58 
59 	ath10k_dbg(ATH10K_DBG_HTC, "%s: skb %p\n", __func__, skb);
60 	return skb;
61 }
62 
63 static inline void ath10k_htc_restore_tx_skb(struct ath10k_htc *htc,
64 					     struct sk_buff *skb)
65 {
66 	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);
67 
68 	dma_unmap_single(htc->ar->dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
69 	skb_pull(skb, sizeof(struct ath10k_htc_hdr));
70 }
71 
72 static void ath10k_htc_notify_tx_completion(struct ath10k_htc_ep *ep,
73 					    struct sk_buff *skb)
74 {
75 	ath10k_dbg(ATH10K_DBG_HTC, "%s: ep %d skb %p\n", __func__,
76 		   ep->eid, skb);
77 
78 	ath10k_htc_restore_tx_skb(ep->htc, skb);
79 
80 	if (!ep->ep_ops.ep_tx_complete) {
81 		ath10k_warn("no tx handler for eid %d\n", ep->eid);
82 		dev_kfree_skb_any(skb);
83 		return;
84 	}
85 
86 	ep->ep_ops.ep_tx_complete(ep->htc->ar, skb);
87 }
88 
89 /* assumes tx_lock is held */
90 static bool ath10k_htc_ep_need_credit_update(struct ath10k_htc_ep *ep)
91 {
92 	if (!ep->tx_credit_flow_enabled)
93 		return false;
94 	if (ep->tx_credits >= ep->tx_credits_per_max_message)
95 		return false;
96 
97 	ath10k_dbg(ATH10K_DBG_HTC, "HTC: endpoint %d needs credit update\n",
98 		   ep->eid);
99 	return true;
100 }
101 
102 static void ath10k_htc_prepare_tx_skb(struct ath10k_htc_ep *ep,
103 				      struct sk_buff *skb)
104 {
105 	struct ath10k_htc_hdr *hdr;
106 
107 	hdr = (struct ath10k_htc_hdr *)skb->data;
108 
109 	hdr->eid = ep->eid;
110 	hdr->len = __cpu_to_le16(skb->len - sizeof(*hdr));
111 	hdr->flags = 0;
112 
113 	spin_lock_bh(&ep->htc->tx_lock);
114 	hdr->seq_no = ep->seq_no++;
115 
116 	if (ath10k_htc_ep_need_credit_update(ep))
117 		hdr->flags |= ATH10K_HTC_FLAG_NEED_CREDIT_UPDATE;
118 
119 	spin_unlock_bh(&ep->htc->tx_lock);
120 }
121 
122 int ath10k_htc_send(struct ath10k_htc *htc,
123 		    enum ath10k_htc_ep_id eid,
124 		    struct sk_buff *skb)
125 {
126 	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
127 	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);
128 	struct ath10k_hif_sg_item sg_item;
129 	struct device *dev = htc->ar->dev;
130 	int credits = 0;
131 	int ret;
132 
133 	if (htc->ar->state == ATH10K_STATE_WEDGED)
134 		return -ECOMM;
135 
136 	if (eid >= ATH10K_HTC_EP_COUNT) {
137 		ath10k_warn("Invalid endpoint id: %d\n", eid);
138 		return -ENOENT;
139 	}
140 
141 	/* FIXME: This looks ugly, can we fix it? */
142 	spin_lock_bh(&htc->tx_lock);
143 	if (htc->stopped) {
144 		spin_unlock_bh(&htc->tx_lock);
145 		return -ESHUTDOWN;
146 	}
147 	spin_unlock_bh(&htc->tx_lock);
148 
149 	skb_push(skb, sizeof(struct ath10k_htc_hdr));
150 
151 	if (ep->tx_credit_flow_enabled) {
152 		credits = DIV_ROUND_UP(skb->len, htc->target_credit_size);
153 		spin_lock_bh(&htc->tx_lock);
154 		if (ep->tx_credits < credits) {
155 			spin_unlock_bh(&htc->tx_lock);
156 			ret = -EAGAIN;
157 			goto err_pull;
158 		}
159 		ep->tx_credits -= credits;
160 		spin_unlock_bh(&htc->tx_lock);
161 	}
162 
163 	ath10k_htc_prepare_tx_skb(ep, skb);
164 
165 	skb_cb->paddr = dma_map_single(dev, skb->data, skb->len, DMA_TO_DEVICE);
166 	ret = dma_mapping_error(dev, skb_cb->paddr);
167 	if (ret)
168 		goto err_credits;
169 
170 	sg_item.transfer_id = ep->eid;
171 	sg_item.transfer_context = skb;
172 	sg_item.vaddr = skb->data;
173 	sg_item.paddr = skb_cb->paddr;
174 	sg_item.len = skb->len;
175 
176 	ret = ath10k_hif_tx_sg(htc->ar, ep->ul_pipe_id, &sg_item, 1);
177 	if (ret)
178 		goto err_unmap;
179 
180 	return 0;
181 
182 err_unmap:
183 	dma_unmap_single(dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
184 err_credits:
185 	if (ep->tx_credit_flow_enabled) {
186 		spin_lock_bh(&htc->tx_lock);
187 		ep->tx_credits += credits;
188 		spin_unlock_bh(&htc->tx_lock);
189 
190 		if (ep->ep_ops.ep_tx_credits)
191 			ep->ep_ops.ep_tx_credits(htc->ar);
192 	}
193 err_pull:
194 	skb_pull(skb, sizeof(struct ath10k_htc_hdr));
195 	return ret;
196 }
197 
198 static int ath10k_htc_tx_completion_handler(struct ath10k *ar,
199 					    struct sk_buff *skb,
200 					    unsigned int eid)
201 {
202 	struct ath10k_htc *htc = &ar->htc;
203 	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
204 
205 	if (WARN_ON_ONCE(!skb))
206 		return 0;
207 
208 	ath10k_htc_notify_tx_completion(ep, skb);
209 	/* the skb now belongs to the completion handler */
210 
211 	return 0;
212 }
213 
214 /***********/
215 /* Receive */
216 /***********/
217 
218 static void
219 ath10k_htc_process_credit_report(struct ath10k_htc *htc,
220 				 const struct ath10k_htc_credit_report *report,
221 				 int len,
222 				 enum ath10k_htc_ep_id eid)
223 {
224 	struct ath10k_htc_ep *ep;
225 	int i, n_reports;
226 
227 	if (len % sizeof(*report))
228 		ath10k_warn("Uneven credit report len %d", len);
229 
230 	n_reports = len / sizeof(*report);
231 
232 	spin_lock_bh(&htc->tx_lock);
233 	for (i = 0; i < n_reports; i++, report++) {
234 		if (report->eid >= ATH10K_HTC_EP_COUNT)
235 			break;
236 
237 		ath10k_dbg(ATH10K_DBG_HTC, "ep %d got %d credits\n",
238 			   report->eid, report->credits);
239 
240 		ep = &htc->endpoint[report->eid];
241 		ep->tx_credits += report->credits;
242 
243 		if (ep->ep_ops.ep_tx_credits) {
244 			spin_unlock_bh(&htc->tx_lock);
245 			ep->ep_ops.ep_tx_credits(htc->ar);
246 			spin_lock_bh(&htc->tx_lock);
247 		}
248 	}
249 	spin_unlock_bh(&htc->tx_lock);
250 }
251 
252 static int ath10k_htc_process_trailer(struct ath10k_htc *htc,
253 				      u8 *buffer,
254 				      int length,
255 				      enum ath10k_htc_ep_id src_eid)
256 {
257 	int status = 0;
258 	struct ath10k_htc_record *record;
259 	u8 *orig_buffer;
260 	int orig_length;
261 	size_t len;
262 
263 	orig_buffer = buffer;
264 	orig_length = length;
265 
266 	while (length > 0) {
267 		record = (struct ath10k_htc_record *)buffer;
268 
269 		if (length < sizeof(record->hdr)) {
270 			status = -EINVAL;
271 			break;
272 		}
273 
274 		if (record->hdr.len > length) {
275 			/* no room left in buffer for record */
276 			ath10k_warn("Invalid record length: %d\n",
277 				    record->hdr.len);
278 			status = -EINVAL;
279 			break;
280 		}
281 
282 		switch (record->hdr.id) {
283 		case ATH10K_HTC_RECORD_CREDITS:
284 			len = sizeof(struct ath10k_htc_credit_report);
285 			if (record->hdr.len < len) {
286 				ath10k_warn("Credit report too long\n");
287 				status = -EINVAL;
288 				break;
289 			}
290 			ath10k_htc_process_credit_report(htc,
291 							 record->credit_report,
292 							 record->hdr.len,
293 							 src_eid);
294 			break;
295 		default:
296 			ath10k_warn("Unhandled record: id:%d length:%d\n",
297 				    record->hdr.id, record->hdr.len);
298 			break;
299 		}
300 
301 		if (status)
302 			break;
303 
304 		/* multiple records may be present in a trailer */
305 		buffer += sizeof(record->hdr) + record->hdr.len;
306 		length -= sizeof(record->hdr) + record->hdr.len;
307 	}
308 
309 	if (status)
310 		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc rx bad trailer", "",
311 				orig_buffer, orig_length);
312 
313 	return status;
314 }
315 
316 static int ath10k_htc_rx_completion_handler(struct ath10k *ar,
317 					    struct sk_buff *skb,
318 					    u8 pipe_id)
319 {
320 	int status = 0;
321 	struct ath10k_htc *htc = &ar->htc;
322 	struct ath10k_htc_hdr *hdr;
323 	struct ath10k_htc_ep *ep;
324 	u16 payload_len;
325 	u32 trailer_len = 0;
326 	size_t min_len;
327 	u8 eid;
328 	bool trailer_present;
329 
330 	hdr = (struct ath10k_htc_hdr *)skb->data;
331 	skb_pull(skb, sizeof(*hdr));
332 
333 	eid = hdr->eid;
334 
335 	if (eid >= ATH10K_HTC_EP_COUNT) {
336 		ath10k_warn("HTC Rx: invalid eid %d\n", eid);
337 		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc bad header", "",
338 				hdr, sizeof(*hdr));
339 		status = -EINVAL;
340 		goto out;
341 	}
342 
343 	ep = &htc->endpoint[eid];
344 
345 	/*
346 	 * If this endpoint that received a message from the target has
347 	 * a to-target HIF pipe whose send completions are polled rather
348 	 * than interrupt-driven, this is a good point to ask HIF to check
349 	 * whether it has any completed sends to handle.
350 	 */
351 	if (ep->ul_is_polled)
352 		ath10k_htc_send_complete_check(ep, 1);
353 
354 	payload_len = __le16_to_cpu(hdr->len);
355 
356 	if (payload_len + sizeof(*hdr) > ATH10K_HTC_MAX_LEN) {
357 		ath10k_warn("HTC rx frame too long, len: %zu\n",
358 			    payload_len + sizeof(*hdr));
359 		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc bad rx pkt len", "",
360 				hdr, sizeof(*hdr));
361 		status = -EINVAL;
362 		goto out;
363 	}
364 
365 	if (skb->len < payload_len) {
366 		ath10k_dbg(ATH10K_DBG_HTC,
367 			   "HTC Rx: insufficient length, got %d, expected %d\n",
368 			   skb->len, payload_len);
369 		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc bad rx pkt len",
370 				"", hdr, sizeof(*hdr));
371 		status = -EINVAL;
372 		goto out;
373 	}
374 
375 	/* get flags to check for trailer */
376 	trailer_present = hdr->flags & ATH10K_HTC_FLAG_TRAILER_PRESENT;
377 	if (trailer_present) {
378 		u8 *trailer;
379 
380 		trailer_len = hdr->trailer_len;
381 		min_len = sizeof(struct ath10k_ath10k_htc_record_hdr);
382 
383 		if ((trailer_len < min_len) ||
384 		    (trailer_len > payload_len)) {
385 			ath10k_warn("Invalid trailer length: %d\n",
386 				    trailer_len);
387 			status = -EPROTO;
388 			goto out;
389 		}
390 
391 		trailer = (u8 *)hdr;
392 		trailer += sizeof(*hdr);
393 		trailer += payload_len;
394 		trailer -= trailer_len;
395 		status = ath10k_htc_process_trailer(htc, trailer,
396 						    trailer_len, hdr->eid);
397 		if (status)
398 			goto out;
399 
400 		skb_trim(skb, skb->len - trailer_len);
401 	}
402 
403 	if (((int)payload_len - (int)trailer_len) <= 0)
404 		/* zero length packet with trailer data, just drop these */
405 		goto out;
406 
407 	if (eid == ATH10K_HTC_EP_0) {
408 		struct ath10k_htc_msg *msg = (struct ath10k_htc_msg *)skb->data;
409 
410 		switch (__le16_to_cpu(msg->hdr.message_id)) {
411 		default:
412 			/* handle HTC control message */
413 			if (completion_done(&htc->ctl_resp)) {
414 				/*
415 				 * this is a fatal error, target should not be
416 				 * sending unsolicited messages on the ep 0
417 				 */
418 				ath10k_warn("HTC rx ctrl still processing\n");
419 				status = -EINVAL;
420 				complete(&htc->ctl_resp);
421 				goto out;
422 			}
423 
424 			htc->control_resp_len =
425 				min_t(int, skb->len,
426 				      ATH10K_HTC_MAX_CTRL_MSG_LEN);
427 
428 			memcpy(htc->control_resp_buffer, skb->data,
429 			       htc->control_resp_len);
430 
431 			complete(&htc->ctl_resp);
432 			break;
433 		case ATH10K_HTC_MSG_SEND_SUSPEND_COMPLETE:
434 			htc->htc_ops.target_send_suspend_complete(ar);
435 		}
436 		goto out;
437 	}
438 
439 	ath10k_dbg(ATH10K_DBG_HTC, "htc rx completion ep %d skb %p\n",
440 		   eid, skb);
441 	ep->ep_ops.ep_rx_complete(ar, skb);
442 
443 	/* skb is now owned by the rx completion handler */
444 	skb = NULL;
445 out:
446 	kfree_skb(skb);
447 
448 	return status;
449 }
450 
451 static void ath10k_htc_control_rx_complete(struct ath10k *ar,
452 					   struct sk_buff *skb)
453 {
454 	/* This is unexpected. FW is not supposed to send regular rx on this
455 	 * endpoint. */
456 	ath10k_warn("unexpected htc rx\n");
457 	kfree_skb(skb);
458 }
459 
460 /***************/
461 /* Init/Deinit */
462 /***************/
463 
464 static const char *htc_service_name(enum ath10k_htc_svc_id id)
465 {
466 	switch (id) {
467 	case ATH10K_HTC_SVC_ID_RESERVED:
468 		return "Reserved";
469 	case ATH10K_HTC_SVC_ID_RSVD_CTRL:
470 		return "Control";
471 	case ATH10K_HTC_SVC_ID_WMI_CONTROL:
472 		return "WMI";
473 	case ATH10K_HTC_SVC_ID_WMI_DATA_BE:
474 		return "DATA BE";
475 	case ATH10K_HTC_SVC_ID_WMI_DATA_BK:
476 		return "DATA BK";
477 	case ATH10K_HTC_SVC_ID_WMI_DATA_VI:
478 		return "DATA VI";
479 	case ATH10K_HTC_SVC_ID_WMI_DATA_VO:
480 		return "DATA VO";
481 	case ATH10K_HTC_SVC_ID_NMI_CONTROL:
482 		return "NMI Control";
483 	case ATH10K_HTC_SVC_ID_NMI_DATA:
484 		return "NMI Data";
485 	case ATH10K_HTC_SVC_ID_HTT_DATA_MSG:
486 		return "HTT Data";
487 	case ATH10K_HTC_SVC_ID_TEST_RAW_STREAMS:
488 		return "RAW";
489 	}
490 
491 	return "Unknown";
492 }
493 
494 static void ath10k_htc_reset_endpoint_states(struct ath10k_htc *htc)
495 {
496 	struct ath10k_htc_ep *ep;
497 	int i;
498 
499 	for (i = ATH10K_HTC_EP_0; i < ATH10K_HTC_EP_COUNT; i++) {
500 		ep = &htc->endpoint[i];
501 		ep->service_id = ATH10K_HTC_SVC_ID_UNUSED;
502 		ep->max_ep_message_len = 0;
503 		ep->max_tx_queue_depth = 0;
504 		ep->eid = i;
505 		ep->htc = htc;
506 		ep->tx_credit_flow_enabled = true;
507 	}
508 }
509 
510 static void ath10k_htc_setup_target_buffer_assignments(struct ath10k_htc *htc)
511 {
512 	struct ath10k_htc_svc_tx_credits *entry;
513 
514 	entry = &htc->service_tx_alloc[0];
515 
516 	/*
517 	 * for PCIE allocate all credists/HTC buffers to WMI.
518 	 * no buffers are used/required for data. data always
519 	 * remains on host.
520 	 */
521 	entry++;
522 	entry->service_id = ATH10K_HTC_SVC_ID_WMI_CONTROL;
523 	entry->credit_allocation = htc->total_transmit_credits;
524 }
525 
526 static u8 ath10k_htc_get_credit_allocation(struct ath10k_htc *htc,
527 					   u16 service_id)
528 {
529 	u8 allocation = 0;
530 	int i;
531 
532 	for (i = 0; i < ATH10K_HTC_EP_COUNT; i++) {
533 		if (htc->service_tx_alloc[i].service_id == service_id)
534 			allocation =
535 			    htc->service_tx_alloc[i].credit_allocation;
536 	}
537 
538 	return allocation;
539 }
540 
541 int ath10k_htc_wait_target(struct ath10k_htc *htc)
542 {
543 	int status = 0;
544 	struct ath10k_htc_svc_conn_req conn_req;
545 	struct ath10k_htc_svc_conn_resp conn_resp;
546 	struct ath10k_htc_msg *msg;
547 	u16 message_id;
548 	u16 credit_count;
549 	u16 credit_size;
550 
551 	status = wait_for_completion_timeout(&htc->ctl_resp,
552 					     ATH10K_HTC_WAIT_TIMEOUT_HZ);
553 	if (status <= 0) {
554 		if (status == 0)
555 			status = -ETIMEDOUT;
556 
557 		ath10k_err("ctl_resp never came in (%d)\n", status);
558 		return status;
559 	}
560 
561 	if (htc->control_resp_len < sizeof(msg->hdr) + sizeof(msg->ready)) {
562 		ath10k_err("Invalid HTC ready msg len:%d\n",
563 			   htc->control_resp_len);
564 		return -ECOMM;
565 	}
566 
567 	msg = (struct ath10k_htc_msg *)htc->control_resp_buffer;
568 	message_id   = __le16_to_cpu(msg->hdr.message_id);
569 	credit_count = __le16_to_cpu(msg->ready.credit_count);
570 	credit_size  = __le16_to_cpu(msg->ready.credit_size);
571 
572 	if (message_id != ATH10K_HTC_MSG_READY_ID) {
573 		ath10k_err("Invalid HTC ready msg: 0x%x\n", message_id);
574 		return -ECOMM;
575 	}
576 
577 	htc->total_transmit_credits = credit_count;
578 	htc->target_credit_size = credit_size;
579 
580 	ath10k_dbg(ATH10K_DBG_HTC,
581 		   "Target ready! transmit resources: %d size:%d\n",
582 		   htc->total_transmit_credits,
583 		   htc->target_credit_size);
584 
585 	if ((htc->total_transmit_credits == 0) ||
586 	    (htc->target_credit_size == 0)) {
587 		ath10k_err("Invalid credit size received\n");
588 		return -ECOMM;
589 	}
590 
591 	ath10k_htc_setup_target_buffer_assignments(htc);
592 
593 	/* setup our pseudo HTC control endpoint connection */
594 	memset(&conn_req, 0, sizeof(conn_req));
595 	memset(&conn_resp, 0, sizeof(conn_resp));
596 	conn_req.ep_ops.ep_tx_complete = ath10k_htc_control_tx_complete;
597 	conn_req.ep_ops.ep_rx_complete = ath10k_htc_control_rx_complete;
598 	conn_req.max_send_queue_depth = ATH10K_NUM_CONTROL_TX_BUFFERS;
599 	conn_req.service_id = ATH10K_HTC_SVC_ID_RSVD_CTRL;
600 
601 	/* connect fake service */
602 	status = ath10k_htc_connect_service(htc, &conn_req, &conn_resp);
603 	if (status) {
604 		ath10k_err("could not connect to htc service (%d)\n", status);
605 		return status;
606 	}
607 
608 	return 0;
609 }
610 
611 int ath10k_htc_connect_service(struct ath10k_htc *htc,
612 			       struct ath10k_htc_svc_conn_req *conn_req,
613 			       struct ath10k_htc_svc_conn_resp *conn_resp)
614 {
615 	struct ath10k_htc_msg *msg;
616 	struct ath10k_htc_conn_svc *req_msg;
617 	struct ath10k_htc_conn_svc_response resp_msg_dummy;
618 	struct ath10k_htc_conn_svc_response *resp_msg = &resp_msg_dummy;
619 	enum ath10k_htc_ep_id assigned_eid = ATH10K_HTC_EP_COUNT;
620 	struct ath10k_htc_ep *ep;
621 	struct sk_buff *skb;
622 	unsigned int max_msg_size = 0;
623 	int length, status;
624 	bool disable_credit_flow_ctrl = false;
625 	u16 message_id, service_id, flags = 0;
626 	u8 tx_alloc = 0;
627 
628 	/* special case for HTC pseudo control service */
629 	if (conn_req->service_id == ATH10K_HTC_SVC_ID_RSVD_CTRL) {
630 		disable_credit_flow_ctrl = true;
631 		assigned_eid = ATH10K_HTC_EP_0;
632 		max_msg_size = ATH10K_HTC_MAX_CTRL_MSG_LEN;
633 		memset(&resp_msg_dummy, 0, sizeof(resp_msg_dummy));
634 		goto setup;
635 	}
636 
637 	tx_alloc = ath10k_htc_get_credit_allocation(htc,
638 						    conn_req->service_id);
639 	if (!tx_alloc)
640 		ath10k_dbg(ATH10K_DBG_BOOT,
641 			   "boot htc service %s does not allocate target credits\n",
642 			   htc_service_name(conn_req->service_id));
643 
644 	skb = ath10k_htc_build_tx_ctrl_skb(htc->ar);
645 	if (!skb) {
646 		ath10k_err("Failed to allocate HTC packet\n");
647 		return -ENOMEM;
648 	}
649 
650 	length = sizeof(msg->hdr) + sizeof(msg->connect_service);
651 	skb_put(skb, length);
652 	memset(skb->data, 0, length);
653 
654 	msg = (struct ath10k_htc_msg *)skb->data;
655 	msg->hdr.message_id =
656 		__cpu_to_le16(ATH10K_HTC_MSG_CONNECT_SERVICE_ID);
657 
658 	flags |= SM(tx_alloc, ATH10K_HTC_CONN_FLAGS_RECV_ALLOC);
659 
660 	/* Only enable credit flow control for WMI ctrl service */
661 	if (conn_req->service_id != ATH10K_HTC_SVC_ID_WMI_CONTROL) {
662 		flags |= ATH10K_HTC_CONN_FLAGS_DISABLE_CREDIT_FLOW_CTRL;
663 		disable_credit_flow_ctrl = true;
664 	}
665 
666 	req_msg = &msg->connect_service;
667 	req_msg->flags = __cpu_to_le16(flags);
668 	req_msg->service_id = __cpu_to_le16(conn_req->service_id);
669 
670 	reinit_completion(&htc->ctl_resp);
671 
672 	status = ath10k_htc_send(htc, ATH10K_HTC_EP_0, skb);
673 	if (status) {
674 		kfree_skb(skb);
675 		return status;
676 	}
677 
678 	/* wait for response */
679 	status = wait_for_completion_timeout(&htc->ctl_resp,
680 					     ATH10K_HTC_CONN_SVC_TIMEOUT_HZ);
681 	if (status <= 0) {
682 		if (status == 0)
683 			status = -ETIMEDOUT;
684 		ath10k_err("Service connect timeout: %d\n", status);
685 		return status;
686 	}
687 
688 	/* we controlled the buffer creation, it's aligned */
689 	msg = (struct ath10k_htc_msg *)htc->control_resp_buffer;
690 	resp_msg = &msg->connect_service_response;
691 	message_id = __le16_to_cpu(msg->hdr.message_id);
692 	service_id = __le16_to_cpu(resp_msg->service_id);
693 
694 	if ((message_id != ATH10K_HTC_MSG_CONNECT_SERVICE_RESP_ID) ||
695 	    (htc->control_resp_len < sizeof(msg->hdr) +
696 	     sizeof(msg->connect_service_response))) {
697 		ath10k_err("Invalid resp message ID 0x%x", message_id);
698 		return -EPROTO;
699 	}
700 
701 	ath10k_dbg(ATH10K_DBG_HTC,
702 		   "HTC Service %s connect response: status: 0x%x, assigned ep: 0x%x\n",
703 		   htc_service_name(service_id),
704 		   resp_msg->status, resp_msg->eid);
705 
706 	conn_resp->connect_resp_code = resp_msg->status;
707 
708 	/* check response status */
709 	if (resp_msg->status != ATH10K_HTC_CONN_SVC_STATUS_SUCCESS) {
710 		ath10k_err("HTC Service %s connect request failed: 0x%x)\n",
711 			   htc_service_name(service_id),
712 			   resp_msg->status);
713 		return -EPROTO;
714 	}
715 
716 	assigned_eid = (enum ath10k_htc_ep_id)resp_msg->eid;
717 	max_msg_size = __le16_to_cpu(resp_msg->max_msg_size);
718 
719 setup:
720 
721 	if (assigned_eid >= ATH10K_HTC_EP_COUNT)
722 		return -EPROTO;
723 
724 	if (max_msg_size == 0)
725 		return -EPROTO;
726 
727 	ep = &htc->endpoint[assigned_eid];
728 	ep->eid = assigned_eid;
729 
730 	if (ep->service_id != ATH10K_HTC_SVC_ID_UNUSED)
731 		return -EPROTO;
732 
733 	/* return assigned endpoint to caller */
734 	conn_resp->eid = assigned_eid;
735 	conn_resp->max_msg_len = __le16_to_cpu(resp_msg->max_msg_size);
736 
737 	/* setup the endpoint */
738 	ep->service_id = conn_req->service_id;
739 	ep->max_tx_queue_depth = conn_req->max_send_queue_depth;
740 	ep->max_ep_message_len = __le16_to_cpu(resp_msg->max_msg_size);
741 	ep->tx_credits = tx_alloc;
742 	ep->tx_credit_size = htc->target_credit_size;
743 	ep->tx_credits_per_max_message = ep->max_ep_message_len /
744 					 htc->target_credit_size;
745 
746 	if (ep->max_ep_message_len % htc->target_credit_size)
747 		ep->tx_credits_per_max_message++;
748 
749 	/* copy all the callbacks */
750 	ep->ep_ops = conn_req->ep_ops;
751 
752 	status = ath10k_hif_map_service_to_pipe(htc->ar,
753 						ep->service_id,
754 						&ep->ul_pipe_id,
755 						&ep->dl_pipe_id,
756 						&ep->ul_is_polled,
757 						&ep->dl_is_polled);
758 	if (status)
759 		return status;
760 
761 	ath10k_dbg(ATH10K_DBG_BOOT,
762 		   "boot htc service '%s' ul pipe %d dl pipe %d eid %d ready\n",
763 		   htc_service_name(ep->service_id), ep->ul_pipe_id,
764 		   ep->dl_pipe_id, ep->eid);
765 
766 	ath10k_dbg(ATH10K_DBG_BOOT,
767 		   "boot htc ep %d ul polled %d dl polled %d\n",
768 		   ep->eid, ep->ul_is_polled, ep->dl_is_polled);
769 
770 	if (disable_credit_flow_ctrl && ep->tx_credit_flow_enabled) {
771 		ep->tx_credit_flow_enabled = false;
772 		ath10k_dbg(ATH10K_DBG_BOOT,
773 			   "boot htc service '%s' eid %d TX flow control disabled\n",
774 			   htc_service_name(ep->service_id), assigned_eid);
775 	}
776 
777 	return status;
778 }
779 
780 struct sk_buff *ath10k_htc_alloc_skb(int size)
781 {
782 	struct sk_buff *skb;
783 
784 	skb = dev_alloc_skb(size + sizeof(struct ath10k_htc_hdr));
785 	if (!skb) {
786 		ath10k_warn("could not allocate HTC tx skb\n");
787 		return NULL;
788 	}
789 
790 	skb_reserve(skb, sizeof(struct ath10k_htc_hdr));
791 
792 	/* FW/HTC requires 4-byte aligned streams */
793 	if (!IS_ALIGNED((unsigned long)skb->data, 4))
794 		ath10k_warn("Unaligned HTC tx skb\n");
795 
796 	return skb;
797 }
798 
799 int ath10k_htc_start(struct ath10k_htc *htc)
800 {
801 	struct sk_buff *skb;
802 	int status = 0;
803 	struct ath10k_htc_msg *msg;
804 
805 	skb = ath10k_htc_build_tx_ctrl_skb(htc->ar);
806 	if (!skb)
807 		return -ENOMEM;
808 
809 	skb_put(skb, sizeof(msg->hdr) + sizeof(msg->setup_complete_ext));
810 	memset(skb->data, 0, skb->len);
811 
812 	msg = (struct ath10k_htc_msg *)skb->data;
813 	msg->hdr.message_id =
814 		__cpu_to_le16(ATH10K_HTC_MSG_SETUP_COMPLETE_EX_ID);
815 
816 	ath10k_dbg(ATH10K_DBG_HTC, "HTC is using TX credit flow control\n");
817 
818 	status = ath10k_htc_send(htc, ATH10K_HTC_EP_0, skb);
819 	if (status) {
820 		kfree_skb(skb);
821 		return status;
822 	}
823 
824 	return 0;
825 }
826 
827 /*
828  * stop HTC communications, i.e. stop interrupt reception, and flush all
829  * queued buffers
830  */
831 void ath10k_htc_stop(struct ath10k_htc *htc)
832 {
833 	spin_lock_bh(&htc->tx_lock);
834 	htc->stopped = true;
835 	spin_unlock_bh(&htc->tx_lock);
836 
837 	ath10k_hif_stop(htc->ar);
838 }
839 
840 /* registered target arrival callback from the HIF layer */
841 int ath10k_htc_init(struct ath10k *ar)
842 {
843 	struct ath10k_hif_cb htc_callbacks;
844 	struct ath10k_htc_ep *ep = NULL;
845 	struct ath10k_htc *htc = &ar->htc;
846 
847 	spin_lock_init(&htc->tx_lock);
848 
849 	htc->stopped = false;
850 	ath10k_htc_reset_endpoint_states(htc);
851 
852 	/* setup HIF layer callbacks */
853 	htc_callbacks.rx_completion = ath10k_htc_rx_completion_handler;
854 	htc_callbacks.tx_completion = ath10k_htc_tx_completion_handler;
855 	htc->ar = ar;
856 
857 	/* Get HIF default pipe for HTC message exchange */
858 	ep = &htc->endpoint[ATH10K_HTC_EP_0];
859 
860 	ath10k_hif_set_callbacks(ar, &htc_callbacks);
861 	ath10k_hif_get_default_pipe(ar, &ep->ul_pipe_id, &ep->dl_pipe_id);
862 
863 	init_completion(&htc->ctl_resp);
864 
865 	return 0;
866 }
867