xref: /linux/drivers/net/wireless/ath/ath10k/htc.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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 		return NULL;
50 
51 	skb_reserve(skb, 20); /* FIXME: why 20 bytes? */
52 	WARN_ONCE((unsigned long)skb->data & 3, "unaligned skb");
53 
54 	skb_cb = ATH10K_SKB_CB(skb);
55 	memset(skb_cb, 0, sizeof(*skb_cb));
56 
57 	ath10k_dbg(ar, ATH10K_DBG_HTC, "%s: skb %p\n", __func__, skb);
58 	return skb;
59 }
60 
61 static inline void ath10k_htc_restore_tx_skb(struct ath10k_htc *htc,
62 					     struct sk_buff *skb)
63 {
64 	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);
65 
66 	dma_unmap_single(htc->ar->dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
67 	skb_pull(skb, sizeof(struct ath10k_htc_hdr));
68 }
69 
70 static void ath10k_htc_notify_tx_completion(struct ath10k_htc_ep *ep,
71 					    struct sk_buff *skb)
72 {
73 	struct ath10k *ar = ep->htc->ar;
74 
75 	ath10k_dbg(ar, 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(ar, "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 	struct ath10k *ar = ep->htc->ar;
93 
94 	if (!ep->tx_credit_flow_enabled)
95 		return false;
96 	if (ep->tx_credits >= ep->tx_credits_per_max_message)
97 		return false;
98 
99 	ath10k_dbg(ar, ATH10K_DBG_HTC, "HTC: endpoint %d needs credit update\n",
100 		   ep->eid);
101 	return true;
102 }
103 
104 static void ath10k_htc_prepare_tx_skb(struct ath10k_htc_ep *ep,
105 				      struct sk_buff *skb)
106 {
107 	struct ath10k_htc_hdr *hdr;
108 
109 	hdr = (struct ath10k_htc_hdr *)skb->data;
110 
111 	hdr->eid = ep->eid;
112 	hdr->len = __cpu_to_le16(skb->len - sizeof(*hdr));
113 	hdr->flags = 0;
114 
115 	spin_lock_bh(&ep->htc->tx_lock);
116 	hdr->seq_no = ep->seq_no++;
117 
118 	if (ath10k_htc_ep_need_credit_update(ep))
119 		hdr->flags |= ATH10K_HTC_FLAG_NEED_CREDIT_UPDATE;
120 
121 	spin_unlock_bh(&ep->htc->tx_lock);
122 }
123 
124 int ath10k_htc_send(struct ath10k_htc *htc,
125 		    enum ath10k_htc_ep_id eid,
126 		    struct sk_buff *skb)
127 {
128 	struct ath10k *ar = htc->ar;
129 	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
130 	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);
131 	struct ath10k_hif_sg_item sg_item;
132 	struct device *dev = htc->ar->dev;
133 	int credits = 0;
134 	int ret;
135 
136 	if (htc->ar->state == ATH10K_STATE_WEDGED)
137 		return -ECOMM;
138 
139 	if (eid >= ATH10K_HTC_EP_COUNT) {
140 		ath10k_warn(ar, "Invalid endpoint id: %d\n", eid);
141 		return -ENOENT;
142 	}
143 
144 	skb_push(skb, sizeof(struct ath10k_htc_hdr));
145 
146 	if (ep->tx_credit_flow_enabled) {
147 		credits = DIV_ROUND_UP(skb->len, htc->target_credit_size);
148 		spin_lock_bh(&htc->tx_lock);
149 		if (ep->tx_credits < credits) {
150 			spin_unlock_bh(&htc->tx_lock);
151 			ret = -EAGAIN;
152 			goto err_pull;
153 		}
154 		ep->tx_credits -= credits;
155 		ath10k_dbg(ar, ATH10K_DBG_HTC,
156 			   "htc ep %d consumed %d credits (total %d)\n",
157 			   eid, credits, ep->tx_credits);
158 		spin_unlock_bh(&htc->tx_lock);
159 	}
160 
161 	ath10k_htc_prepare_tx_skb(ep, skb);
162 
163 	skb_cb->eid = eid;
164 	skb_cb->paddr = dma_map_single(dev, skb->data, skb->len, DMA_TO_DEVICE);
165 	ret = dma_mapping_error(dev, skb_cb->paddr);
166 	if (ret)
167 		goto err_credits;
168 
169 	sg_item.transfer_id = ep->eid;
170 	sg_item.transfer_context = skb;
171 	sg_item.vaddr = skb->data;
172 	sg_item.paddr = skb_cb->paddr;
173 	sg_item.len = skb->len;
174 
175 	ret = ath10k_hif_tx_sg(htc->ar, ep->ul_pipe_id, &sg_item, 1);
176 	if (ret)
177 		goto err_unmap;
178 
179 	return 0;
180 
181 err_unmap:
182 	dma_unmap_single(dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
183 err_credits:
184 	if (ep->tx_credit_flow_enabled) {
185 		spin_lock_bh(&htc->tx_lock);
186 		ep->tx_credits += credits;
187 		ath10k_dbg(ar, ATH10K_DBG_HTC,
188 			   "htc ep %d reverted %d credits back (total %d)\n",
189 			   eid, credits, ep->tx_credits);
190 		spin_unlock_bh(&htc->tx_lock);
191 
192 		if (ep->ep_ops.ep_tx_credits)
193 			ep->ep_ops.ep_tx_credits(htc->ar);
194 	}
195 err_pull:
196 	skb_pull(skb, sizeof(struct ath10k_htc_hdr));
197 	return ret;
198 }
199 
200 static int ath10k_htc_tx_completion_handler(struct ath10k *ar,
201 					    struct sk_buff *skb)
202 {
203 	struct ath10k_htc *htc = &ar->htc;
204 	struct ath10k_skb_cb *skb_cb;
205 	struct ath10k_htc_ep *ep;
206 
207 	if (WARN_ON_ONCE(!skb))
208 		return 0;
209 
210 	skb_cb = ATH10K_SKB_CB(skb);
211 	ep = &htc->endpoint[skb_cb->eid];
212 
213 	ath10k_htc_notify_tx_completion(ep, skb);
214 	/* the skb now belongs to the completion handler */
215 
216 	return 0;
217 }
218 
219 /***********/
220 /* Receive */
221 /***********/
222 
223 static void
224 ath10k_htc_process_credit_report(struct ath10k_htc *htc,
225 				 const struct ath10k_htc_credit_report *report,
226 				 int len,
227 				 enum ath10k_htc_ep_id eid)
228 {
229 	struct ath10k *ar = htc->ar;
230 	struct ath10k_htc_ep *ep;
231 	int i, n_reports;
232 
233 	if (len % sizeof(*report))
234 		ath10k_warn(ar, "Uneven credit report len %d", len);
235 
236 	n_reports = len / sizeof(*report);
237 
238 	spin_lock_bh(&htc->tx_lock);
239 	for (i = 0; i < n_reports; i++, report++) {
240 		if (report->eid >= ATH10K_HTC_EP_COUNT)
241 			break;
242 
243 		ep = &htc->endpoint[report->eid];
244 		ep->tx_credits += report->credits;
245 
246 		ath10k_dbg(ar, ATH10K_DBG_HTC, "htc ep %d got %d credits (total %d)\n",
247 			   report->eid, report->credits, ep->tx_credits);
248 
249 		if (ep->ep_ops.ep_tx_credits) {
250 			spin_unlock_bh(&htc->tx_lock);
251 			ep->ep_ops.ep_tx_credits(htc->ar);
252 			spin_lock_bh(&htc->tx_lock);
253 		}
254 	}
255 	spin_unlock_bh(&htc->tx_lock);
256 }
257 
258 static int ath10k_htc_process_trailer(struct ath10k_htc *htc,
259 				      u8 *buffer,
260 				      int length,
261 				      enum ath10k_htc_ep_id src_eid)
262 {
263 	struct ath10k *ar = htc->ar;
264 	int status = 0;
265 	struct ath10k_htc_record *record;
266 	u8 *orig_buffer;
267 	int orig_length;
268 	size_t len;
269 
270 	orig_buffer = buffer;
271 	orig_length = length;
272 
273 	while (length > 0) {
274 		record = (struct ath10k_htc_record *)buffer;
275 
276 		if (length < sizeof(record->hdr)) {
277 			status = -EINVAL;
278 			break;
279 		}
280 
281 		if (record->hdr.len > length) {
282 			/* no room left in buffer for record */
283 			ath10k_warn(ar, "Invalid record length: %d\n",
284 				    record->hdr.len);
285 			status = -EINVAL;
286 			break;
287 		}
288 
289 		switch (record->hdr.id) {
290 		case ATH10K_HTC_RECORD_CREDITS:
291 			len = sizeof(struct ath10k_htc_credit_report);
292 			if (record->hdr.len < len) {
293 				ath10k_warn(ar, "Credit report too long\n");
294 				status = -EINVAL;
295 				break;
296 			}
297 			ath10k_htc_process_credit_report(htc,
298 							 record->credit_report,
299 							 record->hdr.len,
300 							 src_eid);
301 			break;
302 		default:
303 			ath10k_warn(ar, "Unhandled record: id:%d length:%d\n",
304 				    record->hdr.id, record->hdr.len);
305 			break;
306 		}
307 
308 		if (status)
309 			break;
310 
311 		/* multiple records may be present in a trailer */
312 		buffer += sizeof(record->hdr) + record->hdr.len;
313 		length -= sizeof(record->hdr) + record->hdr.len;
314 	}
315 
316 	if (status)
317 		ath10k_dbg_dump(ar, ATH10K_DBG_HTC, "htc rx bad trailer", "",
318 				orig_buffer, orig_length);
319 
320 	return status;
321 }
322 
323 static int ath10k_htc_rx_completion_handler(struct ath10k *ar,
324 					    struct sk_buff *skb)
325 {
326 	int status = 0;
327 	struct ath10k_htc *htc = &ar->htc;
328 	struct ath10k_htc_hdr *hdr;
329 	struct ath10k_htc_ep *ep;
330 	u16 payload_len;
331 	u32 trailer_len = 0;
332 	size_t min_len;
333 	u8 eid;
334 	bool trailer_present;
335 
336 	hdr = (struct ath10k_htc_hdr *)skb->data;
337 	skb_pull(skb, sizeof(*hdr));
338 
339 	eid = hdr->eid;
340 
341 	if (eid >= ATH10K_HTC_EP_COUNT) {
342 		ath10k_warn(ar, "HTC Rx: invalid eid %d\n", eid);
343 		ath10k_dbg_dump(ar, ATH10K_DBG_HTC, "htc bad header", "",
344 				hdr, sizeof(*hdr));
345 		status = -EINVAL;
346 		goto out;
347 	}
348 
349 	ep = &htc->endpoint[eid];
350 
351 	/*
352 	 * If this endpoint that received a message from the target has
353 	 * a to-target HIF pipe whose send completions are polled rather
354 	 * than interrupt-driven, this is a good point to ask HIF to check
355 	 * whether it has any completed sends to handle.
356 	 */
357 	if (ep->ul_is_polled)
358 		ath10k_htc_send_complete_check(ep, 1);
359 
360 	payload_len = __le16_to_cpu(hdr->len);
361 
362 	if (payload_len + sizeof(*hdr) > ATH10K_HTC_MAX_LEN) {
363 		ath10k_warn(ar, "HTC rx frame too long, len: %zu\n",
364 			    payload_len + sizeof(*hdr));
365 		ath10k_dbg_dump(ar, ATH10K_DBG_HTC, "htc bad rx pkt len", "",
366 				hdr, sizeof(*hdr));
367 		status = -EINVAL;
368 		goto out;
369 	}
370 
371 	if (skb->len < payload_len) {
372 		ath10k_dbg(ar, ATH10K_DBG_HTC,
373 			   "HTC Rx: insufficient length, got %d, expected %d\n",
374 			   skb->len, payload_len);
375 		ath10k_dbg_dump(ar, ATH10K_DBG_HTC, "htc bad rx pkt len",
376 				"", hdr, sizeof(*hdr));
377 		status = -EINVAL;
378 		goto out;
379 	}
380 
381 	/* get flags to check for trailer */
382 	trailer_present = hdr->flags & ATH10K_HTC_FLAG_TRAILER_PRESENT;
383 	if (trailer_present) {
384 		u8 *trailer;
385 
386 		trailer_len = hdr->trailer_len;
387 		min_len = sizeof(struct ath10k_ath10k_htc_record_hdr);
388 
389 		if ((trailer_len < min_len) ||
390 		    (trailer_len > payload_len)) {
391 			ath10k_warn(ar, "Invalid trailer length: %d\n",
392 				    trailer_len);
393 			status = -EPROTO;
394 			goto out;
395 		}
396 
397 		trailer = (u8 *)hdr;
398 		trailer += sizeof(*hdr);
399 		trailer += payload_len;
400 		trailer -= trailer_len;
401 		status = ath10k_htc_process_trailer(htc, trailer,
402 						    trailer_len, hdr->eid);
403 		if (status)
404 			goto out;
405 
406 		skb_trim(skb, skb->len - trailer_len);
407 	}
408 
409 	if (((int)payload_len - (int)trailer_len) <= 0)
410 		/* zero length packet with trailer data, just drop these */
411 		goto out;
412 
413 	if (eid == ATH10K_HTC_EP_0) {
414 		struct ath10k_htc_msg *msg = (struct ath10k_htc_msg *)skb->data;
415 
416 		switch (__le16_to_cpu(msg->hdr.message_id)) {
417 		default:
418 			/* handle HTC control message */
419 			if (completion_done(&htc->ctl_resp)) {
420 				/*
421 				 * this is a fatal error, target should not be
422 				 * sending unsolicited messages on the ep 0
423 				 */
424 				ath10k_warn(ar, "HTC rx ctrl still processing\n");
425 				status = -EINVAL;
426 				complete(&htc->ctl_resp);
427 				goto out;
428 			}
429 
430 			htc->control_resp_len =
431 				min_t(int, skb->len,
432 				      ATH10K_HTC_MAX_CTRL_MSG_LEN);
433 
434 			memcpy(htc->control_resp_buffer, skb->data,
435 			       htc->control_resp_len);
436 
437 			complete(&htc->ctl_resp);
438 			break;
439 		case ATH10K_HTC_MSG_SEND_SUSPEND_COMPLETE:
440 			htc->htc_ops.target_send_suspend_complete(ar);
441 		}
442 		goto out;
443 	}
444 
445 	ath10k_dbg(ar, ATH10K_DBG_HTC, "htc rx completion ep %d skb %p\n",
446 		   eid, skb);
447 	ep->ep_ops.ep_rx_complete(ar, skb);
448 
449 	/* skb is now owned by the rx completion handler */
450 	skb = NULL;
451 out:
452 	kfree_skb(skb);
453 
454 	return status;
455 }
456 
457 static void ath10k_htc_control_rx_complete(struct ath10k *ar,
458 					   struct sk_buff *skb)
459 {
460 	/* This is unexpected. FW is not supposed to send regular rx on this
461 	 * endpoint. */
462 	ath10k_warn(ar, "unexpected htc rx\n");
463 	kfree_skb(skb);
464 }
465 
466 /***************/
467 /* Init/Deinit */
468 /***************/
469 
470 static const char *htc_service_name(enum ath10k_htc_svc_id id)
471 {
472 	switch (id) {
473 	case ATH10K_HTC_SVC_ID_RESERVED:
474 		return "Reserved";
475 	case ATH10K_HTC_SVC_ID_RSVD_CTRL:
476 		return "Control";
477 	case ATH10K_HTC_SVC_ID_WMI_CONTROL:
478 		return "WMI";
479 	case ATH10K_HTC_SVC_ID_WMI_DATA_BE:
480 		return "DATA BE";
481 	case ATH10K_HTC_SVC_ID_WMI_DATA_BK:
482 		return "DATA BK";
483 	case ATH10K_HTC_SVC_ID_WMI_DATA_VI:
484 		return "DATA VI";
485 	case ATH10K_HTC_SVC_ID_WMI_DATA_VO:
486 		return "DATA VO";
487 	case ATH10K_HTC_SVC_ID_NMI_CONTROL:
488 		return "NMI Control";
489 	case ATH10K_HTC_SVC_ID_NMI_DATA:
490 		return "NMI Data";
491 	case ATH10K_HTC_SVC_ID_HTT_DATA_MSG:
492 		return "HTT Data";
493 	case ATH10K_HTC_SVC_ID_TEST_RAW_STREAMS:
494 		return "RAW";
495 	}
496 
497 	return "Unknown";
498 }
499 
500 static void ath10k_htc_reset_endpoint_states(struct ath10k_htc *htc)
501 {
502 	struct ath10k_htc_ep *ep;
503 	int i;
504 
505 	for (i = ATH10K_HTC_EP_0; i < ATH10K_HTC_EP_COUNT; i++) {
506 		ep = &htc->endpoint[i];
507 		ep->service_id = ATH10K_HTC_SVC_ID_UNUSED;
508 		ep->max_ep_message_len = 0;
509 		ep->max_tx_queue_depth = 0;
510 		ep->eid = i;
511 		ep->htc = htc;
512 		ep->tx_credit_flow_enabled = true;
513 	}
514 }
515 
516 static void ath10k_htc_setup_target_buffer_assignments(struct ath10k_htc *htc)
517 {
518 	struct ath10k_htc_svc_tx_credits *entry;
519 
520 	entry = &htc->service_tx_alloc[0];
521 
522 	/*
523 	 * for PCIE allocate all credists/HTC buffers to WMI.
524 	 * no buffers are used/required for data. data always
525 	 * remains on host.
526 	 */
527 	entry++;
528 	entry->service_id = ATH10K_HTC_SVC_ID_WMI_CONTROL;
529 	entry->credit_allocation = htc->total_transmit_credits;
530 }
531 
532 static u8 ath10k_htc_get_credit_allocation(struct ath10k_htc *htc,
533 					   u16 service_id)
534 {
535 	u8 allocation = 0;
536 	int i;
537 
538 	for (i = 0; i < ATH10K_HTC_EP_COUNT; i++) {
539 		if (htc->service_tx_alloc[i].service_id == service_id)
540 			allocation =
541 			    htc->service_tx_alloc[i].credit_allocation;
542 	}
543 
544 	return allocation;
545 }
546 
547 int ath10k_htc_wait_target(struct ath10k_htc *htc)
548 {
549 	struct ath10k *ar = htc->ar;
550 	int i, status = 0;
551 	struct ath10k_htc_svc_conn_req conn_req;
552 	struct ath10k_htc_svc_conn_resp conn_resp;
553 	struct ath10k_htc_msg *msg;
554 	u16 message_id;
555 	u16 credit_count;
556 	u16 credit_size;
557 
558 	status = wait_for_completion_timeout(&htc->ctl_resp,
559 					     ATH10K_HTC_WAIT_TIMEOUT_HZ);
560 	if (status == 0) {
561 		/* Workaround: In some cases the PCI HIF doesn't
562 		 * receive interrupt for the control response message
563 		 * even if the buffer was completed. It is suspected
564 		 * iomap writes unmasking PCI CE irqs aren't propagated
565 		 * properly in KVM PCI-passthrough sometimes.
566 		 */
567 		ath10k_warn(ar, "failed to receive control response completion, polling..\n");
568 
569 		for (i = 0; i < CE_COUNT; i++)
570 			ath10k_hif_send_complete_check(htc->ar, i, 1);
571 
572 		status = wait_for_completion_timeout(&htc->ctl_resp,
573 						     ATH10K_HTC_WAIT_TIMEOUT_HZ);
574 
575 		if (status == 0)
576 			status = -ETIMEDOUT;
577 	}
578 
579 	if (status < 0) {
580 		ath10k_err(ar, "ctl_resp never came in (%d)\n", status);
581 		return status;
582 	}
583 
584 	if (htc->control_resp_len < sizeof(msg->hdr) + sizeof(msg->ready)) {
585 		ath10k_err(ar, "Invalid HTC ready msg len:%d\n",
586 			   htc->control_resp_len);
587 		return -ECOMM;
588 	}
589 
590 	msg = (struct ath10k_htc_msg *)htc->control_resp_buffer;
591 	message_id   = __le16_to_cpu(msg->hdr.message_id);
592 	credit_count = __le16_to_cpu(msg->ready.credit_count);
593 	credit_size  = __le16_to_cpu(msg->ready.credit_size);
594 
595 	if (message_id != ATH10K_HTC_MSG_READY_ID) {
596 		ath10k_err(ar, "Invalid HTC ready msg: 0x%x\n", message_id);
597 		return -ECOMM;
598 	}
599 
600 	htc->total_transmit_credits = credit_count;
601 	htc->target_credit_size = credit_size;
602 
603 	ath10k_dbg(ar, ATH10K_DBG_HTC,
604 		   "Target ready! transmit resources: %d size:%d\n",
605 		   htc->total_transmit_credits,
606 		   htc->target_credit_size);
607 
608 	if ((htc->total_transmit_credits == 0) ||
609 	    (htc->target_credit_size == 0)) {
610 		ath10k_err(ar, "Invalid credit size received\n");
611 		return -ECOMM;
612 	}
613 
614 	ath10k_htc_setup_target_buffer_assignments(htc);
615 
616 	/* setup our pseudo HTC control endpoint connection */
617 	memset(&conn_req, 0, sizeof(conn_req));
618 	memset(&conn_resp, 0, sizeof(conn_resp));
619 	conn_req.ep_ops.ep_tx_complete = ath10k_htc_control_tx_complete;
620 	conn_req.ep_ops.ep_rx_complete = ath10k_htc_control_rx_complete;
621 	conn_req.max_send_queue_depth = ATH10K_NUM_CONTROL_TX_BUFFERS;
622 	conn_req.service_id = ATH10K_HTC_SVC_ID_RSVD_CTRL;
623 
624 	/* connect fake service */
625 	status = ath10k_htc_connect_service(htc, &conn_req, &conn_resp);
626 	if (status) {
627 		ath10k_err(ar, "could not connect to htc service (%d)\n",
628 			   status);
629 		return status;
630 	}
631 
632 	return 0;
633 }
634 
635 int ath10k_htc_connect_service(struct ath10k_htc *htc,
636 			       struct ath10k_htc_svc_conn_req *conn_req,
637 			       struct ath10k_htc_svc_conn_resp *conn_resp)
638 {
639 	struct ath10k *ar = htc->ar;
640 	struct ath10k_htc_msg *msg;
641 	struct ath10k_htc_conn_svc *req_msg;
642 	struct ath10k_htc_conn_svc_response resp_msg_dummy;
643 	struct ath10k_htc_conn_svc_response *resp_msg = &resp_msg_dummy;
644 	enum ath10k_htc_ep_id assigned_eid = ATH10K_HTC_EP_COUNT;
645 	struct ath10k_htc_ep *ep;
646 	struct sk_buff *skb;
647 	unsigned int max_msg_size = 0;
648 	int length, status;
649 	bool disable_credit_flow_ctrl = false;
650 	u16 message_id, service_id, flags = 0;
651 	u8 tx_alloc = 0;
652 
653 	/* special case for HTC pseudo control service */
654 	if (conn_req->service_id == ATH10K_HTC_SVC_ID_RSVD_CTRL) {
655 		disable_credit_flow_ctrl = true;
656 		assigned_eid = ATH10K_HTC_EP_0;
657 		max_msg_size = ATH10K_HTC_MAX_CTRL_MSG_LEN;
658 		memset(&resp_msg_dummy, 0, sizeof(resp_msg_dummy));
659 		goto setup;
660 	}
661 
662 	tx_alloc = ath10k_htc_get_credit_allocation(htc,
663 						    conn_req->service_id);
664 	if (!tx_alloc)
665 		ath10k_dbg(ar, ATH10K_DBG_BOOT,
666 			   "boot htc service %s does not allocate target credits\n",
667 			   htc_service_name(conn_req->service_id));
668 
669 	skb = ath10k_htc_build_tx_ctrl_skb(htc->ar);
670 	if (!skb) {
671 		ath10k_err(ar, "Failed to allocate HTC packet\n");
672 		return -ENOMEM;
673 	}
674 
675 	length = sizeof(msg->hdr) + sizeof(msg->connect_service);
676 	skb_put(skb, length);
677 	memset(skb->data, 0, length);
678 
679 	msg = (struct ath10k_htc_msg *)skb->data;
680 	msg->hdr.message_id =
681 		__cpu_to_le16(ATH10K_HTC_MSG_CONNECT_SERVICE_ID);
682 
683 	flags |= SM(tx_alloc, ATH10K_HTC_CONN_FLAGS_RECV_ALLOC);
684 
685 	/* Only enable credit flow control for WMI ctrl service */
686 	if (conn_req->service_id != ATH10K_HTC_SVC_ID_WMI_CONTROL) {
687 		flags |= ATH10K_HTC_CONN_FLAGS_DISABLE_CREDIT_FLOW_CTRL;
688 		disable_credit_flow_ctrl = true;
689 	}
690 
691 	req_msg = &msg->connect_service;
692 	req_msg->flags = __cpu_to_le16(flags);
693 	req_msg->service_id = __cpu_to_le16(conn_req->service_id);
694 
695 	reinit_completion(&htc->ctl_resp);
696 
697 	status = ath10k_htc_send(htc, ATH10K_HTC_EP_0, skb);
698 	if (status) {
699 		kfree_skb(skb);
700 		return status;
701 	}
702 
703 	/* wait for response */
704 	status = wait_for_completion_timeout(&htc->ctl_resp,
705 					     ATH10K_HTC_CONN_SVC_TIMEOUT_HZ);
706 	if (status == 0) {
707 		ath10k_err(ar, "Service connect timeout: %d\n", status);
708 		return -ETIMEDOUT;
709 	}
710 
711 	/* we controlled the buffer creation, it's aligned */
712 	msg = (struct ath10k_htc_msg *)htc->control_resp_buffer;
713 	resp_msg = &msg->connect_service_response;
714 	message_id = __le16_to_cpu(msg->hdr.message_id);
715 	service_id = __le16_to_cpu(resp_msg->service_id);
716 
717 	if ((message_id != ATH10K_HTC_MSG_CONNECT_SERVICE_RESP_ID) ||
718 	    (htc->control_resp_len < sizeof(msg->hdr) +
719 	     sizeof(msg->connect_service_response))) {
720 		ath10k_err(ar, "Invalid resp message ID 0x%x", message_id);
721 		return -EPROTO;
722 	}
723 
724 	ath10k_dbg(ar, ATH10K_DBG_HTC,
725 		   "HTC Service %s connect response: status: 0x%x, assigned ep: 0x%x\n",
726 		   htc_service_name(service_id),
727 		   resp_msg->status, resp_msg->eid);
728 
729 	conn_resp->connect_resp_code = resp_msg->status;
730 
731 	/* check response status */
732 	if (resp_msg->status != ATH10K_HTC_CONN_SVC_STATUS_SUCCESS) {
733 		ath10k_err(ar, "HTC Service %s connect request failed: 0x%x)\n",
734 			   htc_service_name(service_id),
735 			   resp_msg->status);
736 		return -EPROTO;
737 	}
738 
739 	assigned_eid = (enum ath10k_htc_ep_id)resp_msg->eid;
740 	max_msg_size = __le16_to_cpu(resp_msg->max_msg_size);
741 
742 setup:
743 
744 	if (assigned_eid >= ATH10K_HTC_EP_COUNT)
745 		return -EPROTO;
746 
747 	if (max_msg_size == 0)
748 		return -EPROTO;
749 
750 	ep = &htc->endpoint[assigned_eid];
751 	ep->eid = assigned_eid;
752 
753 	if (ep->service_id != ATH10K_HTC_SVC_ID_UNUSED)
754 		return -EPROTO;
755 
756 	/* return assigned endpoint to caller */
757 	conn_resp->eid = assigned_eid;
758 	conn_resp->max_msg_len = __le16_to_cpu(resp_msg->max_msg_size);
759 
760 	/* setup the endpoint */
761 	ep->service_id = conn_req->service_id;
762 	ep->max_tx_queue_depth = conn_req->max_send_queue_depth;
763 	ep->max_ep_message_len = __le16_to_cpu(resp_msg->max_msg_size);
764 	ep->tx_credits = tx_alloc;
765 	ep->tx_credit_size = htc->target_credit_size;
766 	ep->tx_credits_per_max_message = ep->max_ep_message_len /
767 					 htc->target_credit_size;
768 
769 	if (ep->max_ep_message_len % htc->target_credit_size)
770 		ep->tx_credits_per_max_message++;
771 
772 	/* copy all the callbacks */
773 	ep->ep_ops = conn_req->ep_ops;
774 
775 	status = ath10k_hif_map_service_to_pipe(htc->ar,
776 						ep->service_id,
777 						&ep->ul_pipe_id,
778 						&ep->dl_pipe_id,
779 						&ep->ul_is_polled,
780 						&ep->dl_is_polled);
781 	if (status)
782 		return status;
783 
784 	ath10k_dbg(ar, ATH10K_DBG_BOOT,
785 		   "boot htc service '%s' ul pipe %d dl pipe %d eid %d ready\n",
786 		   htc_service_name(ep->service_id), ep->ul_pipe_id,
787 		   ep->dl_pipe_id, ep->eid);
788 
789 	ath10k_dbg(ar, ATH10K_DBG_BOOT,
790 		   "boot htc ep %d ul polled %d dl polled %d\n",
791 		   ep->eid, ep->ul_is_polled, ep->dl_is_polled);
792 
793 	if (disable_credit_flow_ctrl && ep->tx_credit_flow_enabled) {
794 		ep->tx_credit_flow_enabled = false;
795 		ath10k_dbg(ar, ATH10K_DBG_BOOT,
796 			   "boot htc service '%s' eid %d TX flow control disabled\n",
797 			   htc_service_name(ep->service_id), assigned_eid);
798 	}
799 
800 	return status;
801 }
802 
803 struct sk_buff *ath10k_htc_alloc_skb(struct ath10k *ar, int size)
804 {
805 	struct sk_buff *skb;
806 
807 	skb = dev_alloc_skb(size + sizeof(struct ath10k_htc_hdr));
808 	if (!skb)
809 		return NULL;
810 
811 	skb_reserve(skb, sizeof(struct ath10k_htc_hdr));
812 
813 	/* FW/HTC requires 4-byte aligned streams */
814 	if (!IS_ALIGNED((unsigned long)skb->data, 4))
815 		ath10k_warn(ar, "Unaligned HTC tx skb\n");
816 
817 	return skb;
818 }
819 
820 int ath10k_htc_start(struct ath10k_htc *htc)
821 {
822 	struct ath10k *ar = htc->ar;
823 	struct sk_buff *skb;
824 	int status = 0;
825 	struct ath10k_htc_msg *msg;
826 
827 	skb = ath10k_htc_build_tx_ctrl_skb(htc->ar);
828 	if (!skb)
829 		return -ENOMEM;
830 
831 	skb_put(skb, sizeof(msg->hdr) + sizeof(msg->setup_complete_ext));
832 	memset(skb->data, 0, skb->len);
833 
834 	msg = (struct ath10k_htc_msg *)skb->data;
835 	msg->hdr.message_id =
836 		__cpu_to_le16(ATH10K_HTC_MSG_SETUP_COMPLETE_EX_ID);
837 
838 	ath10k_dbg(ar, ATH10K_DBG_HTC, "HTC is using TX credit flow control\n");
839 
840 	status = ath10k_htc_send(htc, ATH10K_HTC_EP_0, skb);
841 	if (status) {
842 		kfree_skb(skb);
843 		return status;
844 	}
845 
846 	return 0;
847 }
848 
849 /* registered target arrival callback from the HIF layer */
850 int ath10k_htc_init(struct ath10k *ar)
851 {
852 	struct ath10k_hif_cb htc_callbacks;
853 	struct ath10k_htc_ep *ep = NULL;
854 	struct ath10k_htc *htc = &ar->htc;
855 
856 	spin_lock_init(&htc->tx_lock);
857 
858 	ath10k_htc_reset_endpoint_states(htc);
859 
860 	/* setup HIF layer callbacks */
861 	htc_callbacks.rx_completion = ath10k_htc_rx_completion_handler;
862 	htc_callbacks.tx_completion = ath10k_htc_tx_completion_handler;
863 	htc->ar = ar;
864 
865 	/* Get HIF default pipe for HTC message exchange */
866 	ep = &htc->endpoint[ATH10K_HTC_EP_0];
867 
868 	ath10k_hif_set_callbacks(ar, &htc_callbacks);
869 	ath10k_hif_get_default_pipe(ar, &ep->ul_pipe_id, &ep->dl_pipe_id);
870 
871 	init_completion(&htc->ctl_resp);
872 
873 	return 0;
874 }
875