1/*
2 * Copyright (c) 2007-2011 Atheros Communications Inc.
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17#include "core.h"
18#include "debug.h"
19#include "hif-ops.h"
20
21#define HTC_PACKET_CONTAINER_ALLOCATION 32
22#define HTC_CONTROL_BUFFER_SIZE (HTC_MAX_CTRL_MSG_LEN + HTC_HDR_LENGTH)
23
24static int ath6kl_htc_pipe_tx(struct htc_target *handle,
25			      struct htc_packet *packet);
26static void ath6kl_htc_pipe_cleanup(struct htc_target *handle);
27
28/* htc pipe tx path */
29static inline void restore_tx_packet(struct htc_packet *packet)
30{
31	if (packet->info.tx.flags & HTC_FLAGS_TX_FIXUP_NETBUF) {
32		skb_pull(packet->skb, sizeof(struct htc_frame_hdr));
33		packet->info.tx.flags &= ~HTC_FLAGS_TX_FIXUP_NETBUF;
34	}
35}
36
37static void do_send_completion(struct htc_endpoint *ep,
38			       struct list_head *queue_to_indicate)
39{
40	struct htc_packet *packet;
41
42	if (list_empty(queue_to_indicate)) {
43		/* nothing to indicate */
44		return;
45	}
46
47	if (ep->ep_cb.tx_comp_multi != NULL) {
48		ath6kl_dbg(ATH6KL_DBG_HTC,
49			   "%s: calling ep %d, send complete multiple callback (%d pkts)\n",
50			   __func__, ep->eid,
51			   get_queue_depth(queue_to_indicate));
52		/*
53		 * a multiple send complete handler is being used,
54		 * pass the queue to the handler
55		 */
56		ep->ep_cb.tx_comp_multi(ep->target, queue_to_indicate);
57		/*
58		 * all packets are now owned by the callback,
59		 * reset queue to be safe
60		 */
61		INIT_LIST_HEAD(queue_to_indicate);
62	} else {
63		/* using legacy EpTxComplete */
64		do {
65			packet = list_first_entry(queue_to_indicate,
66						  struct htc_packet, list);
67
68			list_del(&packet->list);
69			ath6kl_dbg(ATH6KL_DBG_HTC,
70				   "%s: calling ep %d send complete callback on packet 0x%p\n",
71				   __func__, ep->eid, packet);
72			ep->ep_cb.tx_complete(ep->target, packet);
73		} while (!list_empty(queue_to_indicate));
74	}
75}
76
77static void send_packet_completion(struct htc_target *target,
78				   struct htc_packet *packet)
79{
80	struct htc_endpoint *ep = &target->endpoint[packet->endpoint];
81	struct list_head container;
82
83	restore_tx_packet(packet);
84	INIT_LIST_HEAD(&container);
85	list_add_tail(&packet->list, &container);
86
87	/* do completion */
88	do_send_completion(ep, &container);
89}
90
91static void get_htc_packet_credit_based(struct htc_target *target,
92					struct htc_endpoint *ep,
93					struct list_head *queue)
94{
95	int credits_required;
96	int remainder;
97	u8 send_flags;
98	struct htc_packet *packet;
99	unsigned int transfer_len;
100
101	/* NOTE : the TX lock is held when this function is called */
102
103	/* loop until we can grab as many packets out of the queue as we can */
104	while (true) {
105		send_flags = 0;
106		if (list_empty(&ep->txq))
107			break;
108
109		/* get packet at head, but don't remove it */
110		packet = list_first_entry(&ep->txq, struct htc_packet, list);
111
112		ath6kl_dbg(ATH6KL_DBG_HTC,
113			   "%s: got head packet:0x%p , queue depth: %d\n",
114			   __func__, packet, get_queue_depth(&ep->txq));
115
116		transfer_len = packet->act_len + HTC_HDR_LENGTH;
117
118		if (transfer_len <= target->tgt_cred_sz) {
119			credits_required = 1;
120		} else {
121			/* figure out how many credits this message requires */
122			credits_required = transfer_len / target->tgt_cred_sz;
123			remainder = transfer_len % target->tgt_cred_sz;
124
125			if (remainder)
126				credits_required++;
127		}
128
129		ath6kl_dbg(ATH6KL_DBG_HTC, "%s: creds required:%d got:%d\n",
130			   __func__, credits_required, ep->cred_dist.credits);
131
132		if (ep->eid == ENDPOINT_0) {
133			/*
134			 * endpoint 0 is special, it always has a credit and
135			 * does not require credit based flow control
136			 */
137			credits_required = 0;
138
139		} else {
140			if (ep->cred_dist.credits < credits_required)
141				break;
142
143			ep->cred_dist.credits -= credits_required;
144			ep->ep_st.cred_cosumd += credits_required;
145
146			/* check if we need credits back from the target */
147			if (ep->cred_dist.credits <
148					ep->cred_dist.cred_per_msg) {
149				/* tell the target we need credits ASAP! */
150				send_flags |= HTC_FLAGS_NEED_CREDIT_UPDATE;
151				ep->ep_st.cred_low_indicate += 1;
152				ath6kl_dbg(ATH6KL_DBG_HTC,
153					   "%s: host needs credits\n",
154					   __func__);
155			}
156		}
157
158		/* now we can fully dequeue */
159		packet = list_first_entry(&ep->txq, struct htc_packet, list);
160
161		list_del(&packet->list);
162		/* save the number of credits this packet consumed */
163		packet->info.tx.cred_used = credits_required;
164		/* save send flags */
165		packet->info.tx.flags = send_flags;
166		packet->info.tx.seqno = ep->seqno;
167		ep->seqno++;
168		/* queue this packet into the caller's queue */
169		list_add_tail(&packet->list, queue);
170	}
171}
172
173static void get_htc_packet(struct htc_target *target,
174			   struct htc_endpoint *ep,
175			   struct list_head *queue, int resources)
176{
177	struct htc_packet *packet;
178
179	/* NOTE : the TX lock is held when this function is called */
180
181	/* loop until we can grab as many packets out of the queue as we can */
182	while (resources) {
183		if (list_empty(&ep->txq))
184			break;
185
186		packet = list_first_entry(&ep->txq, struct htc_packet, list);
187		list_del(&packet->list);
188
189		ath6kl_dbg(ATH6KL_DBG_HTC,
190			   "%s: got packet:0x%p , new queue depth: %d\n",
191			   __func__, packet, get_queue_depth(&ep->txq));
192		packet->info.tx.seqno = ep->seqno;
193		packet->info.tx.flags = 0;
194		packet->info.tx.cred_used = 0;
195		ep->seqno++;
196
197		/* queue this packet into the caller's queue */
198		list_add_tail(&packet->list, queue);
199		resources--;
200	}
201}
202
203static int htc_issue_packets(struct htc_target *target,
204			     struct htc_endpoint *ep,
205			     struct list_head *pkt_queue)
206{
207	int status = 0;
208	u16 payload_len;
209	struct sk_buff *skb;
210	struct htc_frame_hdr *htc_hdr;
211	struct htc_packet *packet;
212
213	ath6kl_dbg(ATH6KL_DBG_HTC,
214		   "%s: queue: 0x%p, pkts %d\n", __func__,
215		   pkt_queue, get_queue_depth(pkt_queue));
216
217	while (!list_empty(pkt_queue)) {
218		packet = list_first_entry(pkt_queue, struct htc_packet, list);
219		list_del(&packet->list);
220
221		skb = packet->skb;
222		if (!skb) {
223			WARN_ON_ONCE(1);
224			status = -EINVAL;
225			break;
226		}
227
228		payload_len = packet->act_len;
229
230		/* setup HTC frame header */
231		htc_hdr = skb_push(skb, sizeof(*htc_hdr));
232		if (!htc_hdr) {
233			WARN_ON_ONCE(1);
234			status = -EINVAL;
235			break;
236		}
237
238		packet->info.tx.flags |= HTC_FLAGS_TX_FIXUP_NETBUF;
239
240		/* Endianess? */
241		put_unaligned((u16) payload_len, &htc_hdr->payld_len);
242		htc_hdr->flags = packet->info.tx.flags;
243		htc_hdr->eid = (u8) packet->endpoint;
244		htc_hdr->ctrl[0] = 0;
245		htc_hdr->ctrl[1] = (u8) packet->info.tx.seqno;
246
247		spin_lock_bh(&target->tx_lock);
248
249		/* store in look up queue to match completions */
250		list_add_tail(&packet->list, &ep->pipe.tx_lookup_queue);
251		ep->ep_st.tx_issued += 1;
252		spin_unlock_bh(&target->tx_lock);
253
254		status = ath6kl_hif_pipe_send(target->dev->ar,
255					      ep->pipe.pipeid_ul, NULL, skb);
256
257		if (status != 0) {
258			if (status != -ENOMEM) {
259				/* TODO: if more than 1 endpoint maps to the
260				 * same PipeID, it is possible to run out of
261				 * resources in the HIF layer.
262				 * Don't emit the error
263				 */
264				ath6kl_dbg(ATH6KL_DBG_HTC,
265					   "%s: failed status:%d\n",
266					   __func__, status);
267			}
268			spin_lock_bh(&target->tx_lock);
269			list_del(&packet->list);
270
271			/* reclaim credits */
272			ep->cred_dist.credits += packet->info.tx.cred_used;
273			spin_unlock_bh(&target->tx_lock);
274
275			/* put it back into the callers queue */
276			list_add(&packet->list, pkt_queue);
277			break;
278		}
279	}
280
281	if (status != 0) {
282		while (!list_empty(pkt_queue)) {
283			if (status != -ENOMEM) {
284				ath6kl_dbg(ATH6KL_DBG_HTC,
285					   "%s: failed pkt:0x%p status:%d\n",
286					   __func__, packet, status);
287			}
288
289			packet = list_first_entry(pkt_queue,
290						  struct htc_packet, list);
291			list_del(&packet->list);
292			packet->status = status;
293			send_packet_completion(target, packet);
294		}
295	}
296
297	return status;
298}
299
300static enum htc_send_queue_result htc_try_send(struct htc_target *target,
301					       struct htc_endpoint *ep,
302					       struct list_head *txq)
303{
304	struct list_head send_queue;	/* temp queue to hold packets */
305	struct htc_packet *packet, *tmp_pkt;
306	struct ath6kl *ar = target->dev->ar;
307	enum htc_send_full_action action;
308	int tx_resources, overflow, txqueue_depth, i, good_pkts;
309	u8 pipeid;
310
311	ath6kl_dbg(ATH6KL_DBG_HTC, "%s: (queue:0x%p depth:%d)\n",
312		   __func__, txq,
313		   (txq == NULL) ? 0 : get_queue_depth(txq));
314
315	/* init the local send queue */
316	INIT_LIST_HEAD(&send_queue);
317
318	/*
319	 * txq equals to NULL means
320	 * caller didn't provide a queue, just wants us to
321	 * check queues and send
322	 */
323	if (txq != NULL) {
324		if (list_empty(txq)) {
325			/* empty queue */
326			return HTC_SEND_QUEUE_DROP;
327		}
328
329		spin_lock_bh(&target->tx_lock);
330		txqueue_depth = get_queue_depth(&ep->txq);
331		spin_unlock_bh(&target->tx_lock);
332
333		if (txqueue_depth >= ep->max_txq_depth) {
334			/* we've already overflowed */
335			overflow = get_queue_depth(txq);
336		} else {
337			/* get how much we will overflow by */
338			overflow = txqueue_depth;
339			overflow += get_queue_depth(txq);
340			/* get how much we will overflow the TX queue by */
341			overflow -= ep->max_txq_depth;
342		}
343
344		/* if overflow is negative or zero, we are okay */
345		if (overflow > 0) {
346			ath6kl_dbg(ATH6KL_DBG_HTC,
347				   "%s: Endpoint %d, TX queue will overflow :%d, Tx Depth:%d, Max:%d\n",
348				   __func__, ep->eid, overflow, txqueue_depth,
349				   ep->max_txq_depth);
350		}
351		if ((overflow <= 0) ||
352		    (ep->ep_cb.tx_full == NULL)) {
353			/*
354			 * all packets will fit or caller did not provide send
355			 * full indication handler -- just move all of them
356			 * to the local send_queue object
357			 */
358			list_splice_tail_init(txq, &send_queue);
359		} else {
360			good_pkts = get_queue_depth(txq) - overflow;
361			if (good_pkts < 0) {
362				WARN_ON_ONCE(1);
363				return HTC_SEND_QUEUE_DROP;
364			}
365
366			/* we have overflowed, and a callback is provided */
367			/* dequeue all non-overflow packets to the sendqueue */
368			for (i = 0; i < good_pkts; i++) {
369				/* pop off caller's queue */
370				packet = list_first_entry(txq,
371							  struct htc_packet,
372							  list);
373				/* move to local queue */
374				list_move_tail(&packet->list, &send_queue);
375			}
376
377			/*
378			 * the caller's queue has all the packets that won't fit
379			 * walk through the caller's queue and indicate each to
380			 * the send full handler
381			 */
382			list_for_each_entry_safe(packet, tmp_pkt,
383						 txq, list) {
384				ath6kl_dbg(ATH6KL_DBG_HTC,
385					   "%s: Indicate overflowed TX pkts: %p\n",
386					   __func__, packet);
387				action = ep->ep_cb.tx_full(ep->target, packet);
388				if (action == HTC_SEND_FULL_DROP) {
389					/* callback wants the packet dropped */
390					ep->ep_st.tx_dropped += 1;
391
392					/* leave this one in the caller's queue
393					 * for cleanup */
394				} else {
395					/* callback wants to keep this packet,
396					 * move from caller's queue to the send
397					 * queue */
398					list_move_tail(&packet->list,
399						       &send_queue);
400				}
401			}
402
403			if (list_empty(&send_queue)) {
404				/* no packets made it in, caller will cleanup */
405				return HTC_SEND_QUEUE_DROP;
406			}
407		}
408	}
409
410	if (!ep->pipe.tx_credit_flow_enabled) {
411		tx_resources =
412		    ath6kl_hif_pipe_get_free_queue_number(ar,
413							  ep->pipe.pipeid_ul);
414	} else {
415		tx_resources = 0;
416	}
417
418	spin_lock_bh(&target->tx_lock);
419	if (!list_empty(&send_queue)) {
420		/* transfer packets to tail */
421		list_splice_tail_init(&send_queue, &ep->txq);
422		if (!list_empty(&send_queue)) {
423			WARN_ON_ONCE(1);
424			spin_unlock_bh(&target->tx_lock);
425			return HTC_SEND_QUEUE_DROP;
426		}
427		INIT_LIST_HEAD(&send_queue);
428	}
429
430	/* increment tx processing count on entry */
431	ep->tx_proc_cnt++;
432
433	if (ep->tx_proc_cnt > 1) {
434		/*
435		 * Another thread or task is draining the TX queues on this
436		 * endpoint that thread will reset the tx processing count
437		 * when the queue is drained.
438		 */
439		ep->tx_proc_cnt--;
440		spin_unlock_bh(&target->tx_lock);
441		return HTC_SEND_QUEUE_OK;
442	}
443
444	/***** beyond this point only 1 thread may enter ******/
445
446	/*
447	 * Now drain the endpoint TX queue for transmission as long as we have
448	 * enough transmit resources.
449	 */
450	while (true) {
451		if (get_queue_depth(&ep->txq) == 0)
452			break;
453
454		if (ep->pipe.tx_credit_flow_enabled) {
455			/*
456			 * Credit based mechanism provides flow control
457			 * based on target transmit resource availability,
458			 * we assume that the HIF layer will always have
459			 * bus resources greater than target transmit
460			 * resources.
461			 */
462			get_htc_packet_credit_based(target, ep, &send_queue);
463		} else {
464			/*
465			 * Get all packets for this endpoint that we can
466			 * for this pass.
467			 */
468			get_htc_packet(target, ep, &send_queue, tx_resources);
469		}
470
471		if (get_queue_depth(&send_queue) == 0) {
472			/*
473			 * Didn't get packets due to out of resources or TX
474			 * queue was drained.
475			 */
476			break;
477		}
478
479		spin_unlock_bh(&target->tx_lock);
480
481		/* send what we can */
482		htc_issue_packets(target, ep, &send_queue);
483
484		if (!ep->pipe.tx_credit_flow_enabled) {
485			pipeid = ep->pipe.pipeid_ul;
486			tx_resources =
487			    ath6kl_hif_pipe_get_free_queue_number(ar, pipeid);
488		}
489
490		spin_lock_bh(&target->tx_lock);
491	}
492
493	/* done with this endpoint, we can clear the count */
494	ep->tx_proc_cnt = 0;
495	spin_unlock_bh(&target->tx_lock);
496
497	return HTC_SEND_QUEUE_OK;
498}
499
500/* htc control packet manipulation */
501static void destroy_htc_txctrl_packet(struct htc_packet *packet)
502{
503	struct sk_buff *skb;
504	skb = packet->skb;
505	dev_kfree_skb(skb);
506	kfree(packet);
507}
508
509static struct htc_packet *build_htc_txctrl_packet(void)
510{
511	struct htc_packet *packet = NULL;
512	struct sk_buff *skb;
513
514	packet = kzalloc(sizeof(struct htc_packet), GFP_KERNEL);
515	if (packet == NULL)
516		return NULL;
517
518	skb = __dev_alloc_skb(HTC_CONTROL_BUFFER_SIZE, GFP_KERNEL);
519
520	if (skb == NULL) {
521		kfree(packet);
522		return NULL;
523	}
524	packet->skb = skb;
525
526	return packet;
527}
528
529static void htc_free_txctrl_packet(struct htc_target *target,
530				   struct htc_packet *packet)
531{
532	destroy_htc_txctrl_packet(packet);
533}
534
535static struct htc_packet *htc_alloc_txctrl_packet(struct htc_target *target)
536{
537	return build_htc_txctrl_packet();
538}
539
540static void htc_txctrl_complete(struct htc_target *target,
541				struct htc_packet *packet)
542{
543	htc_free_txctrl_packet(target, packet);
544}
545
546#define MAX_MESSAGE_SIZE 1536
547
548static int htc_setup_target_buffer_assignments(struct htc_target *target)
549{
550	int status, credits, credit_per_maxmsg, i;
551	struct htc_pipe_txcredit_alloc *entry;
552	unsigned int hif_usbaudioclass = 0;
553
554	credit_per_maxmsg = MAX_MESSAGE_SIZE / target->tgt_cred_sz;
555	if (MAX_MESSAGE_SIZE % target->tgt_cred_sz)
556		credit_per_maxmsg++;
557
558	/* TODO, this should be configured by the caller! */
559
560	credits = target->tgt_creds;
561	entry = &target->pipe.txcredit_alloc[0];
562
563	status = -ENOMEM;
564
565	/* FIXME: hif_usbaudioclass is always zero */
566	if (hif_usbaudioclass) {
567		ath6kl_dbg(ATH6KL_DBG_HTC,
568			   "%s: For USB Audio Class- Total:%d\n",
569			   __func__, credits);
570		entry++;
571		entry++;
572		/* Setup VO Service To have Max Credits */
573		entry->service_id = WMI_DATA_VO_SVC;
574		entry->credit_alloc = (credits - 6);
575		if (entry->credit_alloc == 0)
576			entry->credit_alloc++;
577
578		credits -= (int) entry->credit_alloc;
579		if (credits <= 0)
580			return status;
581
582		entry++;
583		entry->service_id = WMI_CONTROL_SVC;
584		entry->credit_alloc = credit_per_maxmsg;
585		credits -= (int) entry->credit_alloc;
586		if (credits <= 0)
587			return status;
588
589		/* leftovers go to best effort */
590		entry++;
591		entry++;
592		entry->service_id = WMI_DATA_BE_SVC;
593		entry->credit_alloc = (u8) credits;
594		status = 0;
595	} else {
596		entry++;
597		entry->service_id = WMI_DATA_VI_SVC;
598		entry->credit_alloc = credits / 4;
599		if (entry->credit_alloc == 0)
600			entry->credit_alloc++;
601
602		credits -= (int) entry->credit_alloc;
603		if (credits <= 0)
604			return status;
605
606		entry++;
607		entry->service_id = WMI_DATA_VO_SVC;
608		entry->credit_alloc = credits / 4;
609		if (entry->credit_alloc == 0)
610			entry->credit_alloc++;
611
612		credits -= (int) entry->credit_alloc;
613		if (credits <= 0)
614			return status;
615
616		entry++;
617		entry->service_id = WMI_CONTROL_SVC;
618		entry->credit_alloc = credit_per_maxmsg;
619		credits -= (int) entry->credit_alloc;
620		if (credits <= 0)
621			return status;
622
623		entry++;
624		entry->service_id = WMI_DATA_BK_SVC;
625		entry->credit_alloc = credit_per_maxmsg;
626		credits -= (int) entry->credit_alloc;
627		if (credits <= 0)
628			return status;
629
630		/* leftovers go to best effort */
631		entry++;
632		entry->service_id = WMI_DATA_BE_SVC;
633		entry->credit_alloc = (u8) credits;
634		status = 0;
635	}
636
637	if (status == 0) {
638		for (i = 0; i < ENDPOINT_MAX; i++) {
639			if (target->pipe.txcredit_alloc[i].service_id != 0) {
640				ath6kl_dbg(ATH6KL_DBG_HTC,
641					   "HTC Service Index : %d TX : 0x%2.2X : alloc:%d\n",
642					   i,
643					   target->pipe.txcredit_alloc[i].
644					   service_id,
645					   target->pipe.txcredit_alloc[i].
646					   credit_alloc);
647			}
648		}
649	}
650	return status;
651}
652
653/* process credit reports and call distribution function */
654static void htc_process_credit_report(struct htc_target *target,
655				      struct htc_credit_report *rpt,
656				      int num_entries,
657				      enum htc_endpoint_id from_ep)
658{
659	int total_credits = 0, i;
660	struct htc_endpoint *ep;
661
662	/* lock out TX while we update credits */
663	spin_lock_bh(&target->tx_lock);
664
665	for (i = 0; i < num_entries; i++, rpt++) {
666		if (rpt->eid >= ENDPOINT_MAX) {
667			WARN_ON_ONCE(1);
668			spin_unlock_bh(&target->tx_lock);
669			return;
670		}
671
672		ep = &target->endpoint[rpt->eid];
673		ep->cred_dist.credits += rpt->credits;
674
675		if (ep->cred_dist.credits && get_queue_depth(&ep->txq)) {
676			spin_unlock_bh(&target->tx_lock);
677			htc_try_send(target, ep, NULL);
678			spin_lock_bh(&target->tx_lock);
679		}
680
681		total_credits += rpt->credits;
682	}
683	ath6kl_dbg(ATH6KL_DBG_HTC,
684		   "Report indicated %d credits to distribute\n",
685		   total_credits);
686
687	spin_unlock_bh(&target->tx_lock);
688}
689
690/* flush endpoint TX queue */
691static void htc_flush_tx_endpoint(struct htc_target *target,
692				  struct htc_endpoint *ep, u16 tag)
693{
694	struct htc_packet *packet;
695
696	spin_lock_bh(&target->tx_lock);
697	while (get_queue_depth(&ep->txq)) {
698		packet = list_first_entry(&ep->txq, struct htc_packet, list);
699		list_del(&packet->list);
700		packet->status = 0;
701		send_packet_completion(target, packet);
702	}
703	spin_unlock_bh(&target->tx_lock);
704}
705
706/*
707 * In the adapted HIF layer, struct sk_buff * are passed between HIF and HTC,
708 * since upper layers expects struct htc_packet containers we use the completed
709 * skb and lookup it's corresponding HTC packet buffer from a lookup list.
710 * This is extra overhead that can be fixed by re-aligning HIF interfaces with
711 * HTC.
712 */
713static struct htc_packet *htc_lookup_tx_packet(struct htc_target *target,
714					       struct htc_endpoint *ep,
715					       struct sk_buff *skb)
716{
717	struct htc_packet *packet, *tmp_pkt, *found_packet = NULL;
718
719	spin_lock_bh(&target->tx_lock);
720
721	/*
722	 * interate from the front of tx lookup queue
723	 * this lookup should be fast since lower layers completes in-order and
724	 * so the completed packet should be at the head of the list generally
725	 */
726	list_for_each_entry_safe(packet, tmp_pkt, &ep->pipe.tx_lookup_queue,
727				 list) {
728		/* check for removal */
729		if (skb == packet->skb) {
730			/* found it */
731			list_del(&packet->list);
732			found_packet = packet;
733			break;
734		}
735	}
736
737	spin_unlock_bh(&target->tx_lock);
738
739	return found_packet;
740}
741
742static int ath6kl_htc_pipe_tx_complete(struct ath6kl *ar, struct sk_buff *skb)
743{
744	struct htc_target *target = ar->htc_target;
745	struct htc_frame_hdr *htc_hdr;
746	struct htc_endpoint *ep;
747	struct htc_packet *packet;
748	u8 ep_id, *netdata;
749
750	netdata = skb->data;
751
752	htc_hdr = (struct htc_frame_hdr *) netdata;
753
754	ep_id = htc_hdr->eid;
755	ep = &target->endpoint[ep_id];
756
757	packet = htc_lookup_tx_packet(target, ep, skb);
758	if (packet == NULL) {
759		/* may have already been flushed and freed */
760		ath6kl_err("HTC TX lookup failed!\n");
761	} else {
762		/* will be giving this buffer back to upper layers */
763		packet->status = 0;
764		send_packet_completion(target, packet);
765	}
766	skb = NULL;
767
768	if (!ep->pipe.tx_credit_flow_enabled) {
769		/*
770		 * note: when using TX credit flow, the re-checking of queues
771		 * happens when credits flow back from the target. in the
772		 * non-TX credit case, we recheck after the packet completes
773		 */
774		htc_try_send(target, ep, NULL);
775	}
776
777	return 0;
778}
779
780static int htc_send_packets_multiple(struct htc_target *target,
781				     struct list_head *pkt_queue)
782{
783	struct htc_endpoint *ep;
784	struct htc_packet *packet, *tmp_pkt;
785
786	if (list_empty(pkt_queue))
787		return -EINVAL;
788
789	/* get first packet to find out which ep the packets will go into */
790	packet = list_first_entry(pkt_queue, struct htc_packet, list);
791
792	if (packet->endpoint >= ENDPOINT_MAX) {
793		WARN_ON_ONCE(1);
794		return -EINVAL;
795	}
796	ep = &target->endpoint[packet->endpoint];
797
798	htc_try_send(target, ep, pkt_queue);
799
800	/* do completion on any packets that couldn't get in */
801	if (!list_empty(pkt_queue)) {
802		list_for_each_entry_safe(packet, tmp_pkt, pkt_queue, list) {
803			packet->status = -ENOMEM;
804		}
805
806		do_send_completion(ep, pkt_queue);
807	}
808
809	return 0;
810}
811
812/* htc pipe rx path */
813static struct htc_packet *alloc_htc_packet_container(struct htc_target *target)
814{
815	struct htc_packet *packet;
816	spin_lock_bh(&target->rx_lock);
817
818	if (target->pipe.htc_packet_pool == NULL) {
819		spin_unlock_bh(&target->rx_lock);
820		return NULL;
821	}
822
823	packet = target->pipe.htc_packet_pool;
824	target->pipe.htc_packet_pool = (struct htc_packet *) packet->list.next;
825
826	spin_unlock_bh(&target->rx_lock);
827
828	packet->list.next = NULL;
829	return packet;
830}
831
832static void free_htc_packet_container(struct htc_target *target,
833				      struct htc_packet *packet)
834{
835	struct list_head *lh;
836
837	spin_lock_bh(&target->rx_lock);
838
839	if (target->pipe.htc_packet_pool == NULL) {
840		target->pipe.htc_packet_pool = packet;
841		packet->list.next = NULL;
842	} else {
843		lh = (struct list_head *) target->pipe.htc_packet_pool;
844		packet->list.next = lh;
845		target->pipe.htc_packet_pool = packet;
846	}
847
848	spin_unlock_bh(&target->rx_lock);
849}
850
851static int htc_process_trailer(struct htc_target *target, u8 *buffer,
852			       int len, enum htc_endpoint_id from_ep)
853{
854	struct htc_credit_report *report;
855	struct htc_record_hdr *record;
856	u8 *record_buf;
857	int status = 0;
858
859	while (len > 0) {
860		if (len < sizeof(struct htc_record_hdr)) {
861			status = -EINVAL;
862			break;
863		}
864
865		/* these are byte aligned structs */
866		record = (struct htc_record_hdr *) buffer;
867		len -= sizeof(struct htc_record_hdr);
868		buffer += sizeof(struct htc_record_hdr);
869
870		if (record->len > len) {
871			/* no room left in buffer for record */
872			ath6kl_dbg(ATH6KL_DBG_HTC,
873				   "invalid length: %d (id:%d) buffer has: %d bytes left\n",
874				   record->len, record->rec_id, len);
875			status = -EINVAL;
876			break;
877		}
878
879		/* start of record follows the header */
880		record_buf = buffer;
881
882		switch (record->rec_id) {
883		case HTC_RECORD_CREDITS:
884			if (record->len < sizeof(struct htc_credit_report)) {
885				WARN_ON_ONCE(1);
886				return -EINVAL;
887			}
888
889			report = (struct htc_credit_report *) record_buf;
890			htc_process_credit_report(target, report,
891						  record->len / sizeof(*report),
892						  from_ep);
893			break;
894		default:
895			ath6kl_dbg(ATH6KL_DBG_HTC,
896				   "unhandled record: id:%d length:%d\n",
897				   record->rec_id, record->len);
898			break;
899		}
900
901		/* advance buffer past this record for next time around */
902		buffer += record->len;
903		len -= record->len;
904	}
905
906	return status;
907}
908
909static void do_recv_completion(struct htc_endpoint *ep,
910			       struct list_head *queue_to_indicate)
911{
912	struct htc_packet *packet;
913
914	if (list_empty(queue_to_indicate)) {
915		/* nothing to indicate */
916		return;
917	}
918
919	/* using legacy EpRecv */
920	while (!list_empty(queue_to_indicate)) {
921		packet = list_first_entry(queue_to_indicate,
922					  struct htc_packet, list);
923		list_del(&packet->list);
924		ep->ep_cb.rx(ep->target, packet);
925	}
926
927	return;
928}
929
930static void recv_packet_completion(struct htc_target *target,
931				   struct htc_endpoint *ep,
932				   struct htc_packet *packet)
933{
934	struct list_head container;
935	INIT_LIST_HEAD(&container);
936	list_add_tail(&packet->list, &container);
937
938	/* do completion */
939	do_recv_completion(ep, &container);
940}
941
942static int ath6kl_htc_pipe_rx_complete(struct ath6kl *ar, struct sk_buff *skb,
943				       u8 pipeid)
944{
945	struct htc_target *target = ar->htc_target;
946	u8 *netdata, *trailer, hdr_info;
947	struct htc_frame_hdr *htc_hdr;
948	u32 netlen, trailerlen = 0;
949	struct htc_packet *packet;
950	struct htc_endpoint *ep;
951	u16 payload_len;
952	int status = 0;
953
954	/*
955	 * ar->htc_target can be NULL due to a race condition that can occur
956	 * during driver initialization(we do 'ath6kl_hif_power_on' before
957	 * initializing 'ar->htc_target' via 'ath6kl_htc_create').
958	 * 'ath6kl_hif_power_on' assigns 'ath6kl_recv_complete' as
959	 * usb_complete_t/callback function for 'usb_fill_bulk_urb'.
960	 * Thus the possibility of ar->htc_target being NULL
961	 * via ath6kl_recv_complete -> ath6kl_usb_io_comp_work.
962	 */
963	if (!target) {
964		ath6kl_dbg(ATH6KL_DBG_HTC, "Target not yet initialized\n");
965		status = -EINVAL;
966		goto free_skb;
967	}
968
969
970	netdata = skb->data;
971	netlen = skb->len;
972
973	htc_hdr = (struct htc_frame_hdr *) netdata;
974
975	if (htc_hdr->eid >= ENDPOINT_MAX) {
976		ath6kl_dbg(ATH6KL_DBG_HTC,
977			   "HTC Rx: invalid EndpointID=%d\n",
978			   htc_hdr->eid);
979		status = -EINVAL;
980		goto free_skb;
981	}
982	ep = &target->endpoint[htc_hdr->eid];
983
984	payload_len = le16_to_cpu(get_unaligned(&htc_hdr->payld_len));
985
986	if (netlen < (payload_len + HTC_HDR_LENGTH)) {
987		ath6kl_dbg(ATH6KL_DBG_HTC,
988			   "HTC Rx: insufficient length, got:%d expected =%zu\n",
989			   netlen, payload_len + HTC_HDR_LENGTH);
990		status = -EINVAL;
991		goto free_skb;
992	}
993
994	/* get flags to check for trailer */
995	hdr_info = htc_hdr->flags;
996	if (hdr_info & HTC_FLG_RX_TRAILER) {
997		/* extract the trailer length */
998		hdr_info = htc_hdr->ctrl[0];
999		if ((hdr_info < sizeof(struct htc_record_hdr)) ||
1000		    (hdr_info > payload_len)) {
1001			ath6kl_dbg(ATH6KL_DBG_HTC,
1002				   "invalid header: payloadlen should be %d, CB[0]: %d\n",
1003				   payload_len, hdr_info);
1004			status = -EINVAL;
1005			goto free_skb;
1006		}
1007
1008		trailerlen = hdr_info;
1009		/* process trailer after hdr/apps payload */
1010		trailer = (u8 *) htc_hdr + HTC_HDR_LENGTH +
1011			payload_len - hdr_info;
1012		status = htc_process_trailer(target, trailer, hdr_info,
1013					     htc_hdr->eid);
1014		if (status != 0)
1015			goto free_skb;
1016	}
1017
1018	if (((int) payload_len - (int) trailerlen) <= 0) {
1019		/* zero length packet with trailer, just drop these */
1020		goto free_skb;
1021	}
1022
1023	if (htc_hdr->eid == ENDPOINT_0) {
1024		/* handle HTC control message */
1025		if (target->htc_flags & HTC_OP_STATE_SETUP_COMPLETE) {
1026			/*
1027			 * fatal: target should not send unsolicited
1028			 * messageson the endpoint 0
1029			 */
1030			ath6kl_dbg(ATH6KL_DBG_HTC,
1031				   "HTC ignores Rx Ctrl after setup complete\n");
1032			status = -EINVAL;
1033			goto free_skb;
1034		}
1035
1036		/* remove HTC header */
1037		skb_pull(skb, HTC_HDR_LENGTH);
1038
1039		netdata = skb->data;
1040		netlen = skb->len;
1041
1042		spin_lock_bh(&target->rx_lock);
1043
1044		target->pipe.ctrl_response_valid = true;
1045		target->pipe.ctrl_response_len = min_t(int, netlen,
1046						       HTC_MAX_CTRL_MSG_LEN);
1047		memcpy(target->pipe.ctrl_response_buf, netdata,
1048		       target->pipe.ctrl_response_len);
1049
1050		spin_unlock_bh(&target->rx_lock);
1051
1052		dev_kfree_skb(skb);
1053		skb = NULL;
1054
1055		goto free_skb;
1056	}
1057
1058	/*
1059	 * TODO: the message based HIF architecture allocates net bufs
1060	 * for recv packets since it bridges that HIF to upper layers,
1061	 * which expects HTC packets, we form the packets here
1062	 */
1063	packet = alloc_htc_packet_container(target);
1064	if (packet == NULL) {
1065		status = -ENOMEM;
1066		goto free_skb;
1067	}
1068
1069	packet->status = 0;
1070	packet->endpoint = htc_hdr->eid;
1071	packet->pkt_cntxt = skb;
1072
1073	/* TODO: for backwards compatibility */
1074	packet->buf = skb_push(skb, 0) + HTC_HDR_LENGTH;
1075	packet->act_len = netlen - HTC_HDR_LENGTH - trailerlen;
1076
1077	/*
1078	 * TODO: this is a hack because the driver layer will set the
1079	 * actual len of the skb again which will just double the len
1080	 */
1081	skb_trim(skb, 0);
1082
1083	recv_packet_completion(target, ep, packet);
1084
1085	/* recover the packet container */
1086	free_htc_packet_container(target, packet);
1087	skb = NULL;
1088
1089free_skb:
1090	dev_kfree_skb(skb);
1091
1092	return status;
1093}
1094
1095static void htc_flush_rx_queue(struct htc_target *target,
1096			       struct htc_endpoint *ep)
1097{
1098	struct list_head container;
1099	struct htc_packet *packet;
1100
1101	spin_lock_bh(&target->rx_lock);
1102
1103	while (1) {
1104		if (list_empty(&ep->rx_bufq))
1105			break;
1106
1107		packet = list_first_entry(&ep->rx_bufq,
1108					  struct htc_packet, list);
1109		list_del(&packet->list);
1110
1111		spin_unlock_bh(&target->rx_lock);
1112		packet->status = -ECANCELED;
1113		packet->act_len = 0;
1114
1115		ath6kl_dbg(ATH6KL_DBG_HTC,
1116			   "Flushing RX packet:0x%p, length:%d, ep:%d\n",
1117			   packet, packet->buf_len,
1118			   packet->endpoint);
1119
1120		INIT_LIST_HEAD(&container);
1121		list_add_tail(&packet->list, &container);
1122
1123		/* give the packet back */
1124		do_recv_completion(ep, &container);
1125		spin_lock_bh(&target->rx_lock);
1126	}
1127
1128	spin_unlock_bh(&target->rx_lock);
1129}
1130
1131/* polling routine to wait for a control packet to be received */
1132static int htc_wait_recv_ctrl_message(struct htc_target *target)
1133{
1134	int count = HTC_TARGET_RESPONSE_POLL_COUNT;
1135
1136	while (count > 0) {
1137		spin_lock_bh(&target->rx_lock);
1138
1139		if (target->pipe.ctrl_response_valid) {
1140			target->pipe.ctrl_response_valid = false;
1141			spin_unlock_bh(&target->rx_lock);
1142			break;
1143		}
1144
1145		spin_unlock_bh(&target->rx_lock);
1146
1147		count--;
1148
1149		msleep_interruptible(HTC_TARGET_RESPONSE_POLL_WAIT);
1150	}
1151
1152	if (count <= 0) {
1153		ath6kl_warn("htc pipe control receive timeout!\n");
1154		return -ETIMEDOUT;
1155	}
1156
1157	return 0;
1158}
1159
1160static void htc_rxctrl_complete(struct htc_target *context,
1161				struct htc_packet *packet)
1162{
1163	struct sk_buff *skb = packet->skb;
1164
1165	if (packet->endpoint == ENDPOINT_0 &&
1166	    packet->status == -ECANCELED &&
1167	    skb != NULL)
1168		dev_kfree_skb(skb);
1169}
1170
1171/* htc pipe initialization */
1172static void reset_endpoint_states(struct htc_target *target)
1173{
1174	struct htc_endpoint *ep;
1175	int i;
1176
1177	for (i = ENDPOINT_0; i < ENDPOINT_MAX; i++) {
1178		ep = &target->endpoint[i];
1179		ep->svc_id = 0;
1180		ep->len_max = 0;
1181		ep->max_txq_depth = 0;
1182		ep->eid = i;
1183		INIT_LIST_HEAD(&ep->txq);
1184		INIT_LIST_HEAD(&ep->pipe.tx_lookup_queue);
1185		INIT_LIST_HEAD(&ep->rx_bufq);
1186		ep->target = target;
1187		ep->pipe.tx_credit_flow_enabled = true;
1188	}
1189}
1190
1191/* start HTC, this is called after all services are connected */
1192static int htc_config_target_hif_pipe(struct htc_target *target)
1193{
1194	return 0;
1195}
1196
1197/* htc service functions */
1198static u8 htc_get_credit_alloc(struct htc_target *target, u16 service_id)
1199{
1200	u8 allocation = 0;
1201	int i;
1202
1203	for (i = 0; i < ENDPOINT_MAX; i++) {
1204		if (target->pipe.txcredit_alloc[i].service_id == service_id)
1205			allocation =
1206				target->pipe.txcredit_alloc[i].credit_alloc;
1207	}
1208
1209	if (allocation == 0) {
1210		ath6kl_dbg(ATH6KL_DBG_HTC,
1211			   "HTC Service TX : 0x%2.2X : allocation is zero!\n",
1212			   service_id);
1213	}
1214
1215	return allocation;
1216}
1217
1218static int ath6kl_htc_pipe_conn_service(struct htc_target *target,
1219		     struct htc_service_connect_req *conn_req,
1220		     struct htc_service_connect_resp *conn_resp)
1221{
1222	struct ath6kl *ar = target->dev->ar;
1223	struct htc_packet *packet = NULL;
1224	struct htc_conn_service_resp *resp_msg;
1225	struct htc_conn_service_msg *conn_msg;
1226	enum htc_endpoint_id assigned_epid = ENDPOINT_MAX;
1227	bool disable_credit_flowctrl = false;
1228	unsigned int max_msg_size = 0;
1229	struct htc_endpoint *ep;
1230	int length, status = 0;
1231	struct sk_buff *skb;
1232	u8 tx_alloc;
1233	u16 flags;
1234
1235	if (conn_req->svc_id == 0) {
1236		WARN_ON_ONCE(1);
1237		status = -EINVAL;
1238		goto free_packet;
1239	}
1240
1241	if (conn_req->svc_id == HTC_CTRL_RSVD_SVC) {
1242		/* special case for pseudo control service */
1243		assigned_epid = ENDPOINT_0;
1244		max_msg_size = HTC_MAX_CTRL_MSG_LEN;
1245		tx_alloc = 0;
1246
1247	} else {
1248		tx_alloc = htc_get_credit_alloc(target, conn_req->svc_id);
1249		if (tx_alloc == 0) {
1250			status = -ENOMEM;
1251			goto free_packet;
1252		}
1253
1254		/* allocate a packet to send to the target */
1255		packet = htc_alloc_txctrl_packet(target);
1256
1257		if (packet == NULL) {
1258			WARN_ON_ONCE(1);
1259			status = -ENOMEM;
1260			goto free_packet;
1261		}
1262
1263		skb = packet->skb;
1264		length = sizeof(struct htc_conn_service_msg);
1265
1266		/* assemble connect service message */
1267		conn_msg = skb_put(skb, length);
1268		if (conn_msg == NULL) {
1269			WARN_ON_ONCE(1);
1270			status = -EINVAL;
1271			goto free_packet;
1272		}
1273
1274		memset(conn_msg, 0,
1275		       sizeof(struct htc_conn_service_msg));
1276		conn_msg->msg_id = cpu_to_le16(HTC_MSG_CONN_SVC_ID);
1277		conn_msg->svc_id = cpu_to_le16(conn_req->svc_id);
1278		conn_msg->conn_flags = cpu_to_le16(conn_req->conn_flags &
1279					~HTC_CONN_FLGS_SET_RECV_ALLOC_MASK);
1280
1281		/* tell target desired recv alloc for this ep */
1282		flags = tx_alloc << HTC_CONN_FLGS_SET_RECV_ALLOC_SHIFT;
1283		conn_msg->conn_flags |= cpu_to_le16(flags);
1284
1285		if (conn_req->conn_flags &
1286		    HTC_CONN_FLGS_DISABLE_CRED_FLOW_CTRL) {
1287			disable_credit_flowctrl = true;
1288		}
1289
1290		set_htc_pkt_info(packet, NULL, (u8 *) conn_msg,
1291				 length,
1292				 ENDPOINT_0, HTC_SERVICE_TX_PACKET_TAG);
1293
1294		status = ath6kl_htc_pipe_tx(target, packet);
1295
1296		/* we don't own it anymore */
1297		packet = NULL;
1298		if (status != 0)
1299			goto free_packet;
1300
1301		/* wait for response */
1302		status = htc_wait_recv_ctrl_message(target);
1303		if (status != 0)
1304			goto free_packet;
1305
1306		/* we controlled the buffer creation so it has to be
1307		 * properly aligned
1308		 */
1309		resp_msg = (struct htc_conn_service_resp *)
1310		    target->pipe.ctrl_response_buf;
1311
1312		if (resp_msg->msg_id != cpu_to_le16(HTC_MSG_CONN_SVC_RESP_ID) ||
1313		    (target->pipe.ctrl_response_len < sizeof(*resp_msg))) {
1314			/* this message is not valid */
1315			WARN_ON_ONCE(1);
1316			status = -EINVAL;
1317			goto free_packet;
1318		}
1319
1320		ath6kl_dbg(ATH6KL_DBG_TRC,
1321			   "%s: service 0x%X conn resp: status: %d ep: %d\n",
1322			   __func__, resp_msg->svc_id, resp_msg->status,
1323			   resp_msg->eid);
1324
1325		conn_resp->resp_code = resp_msg->status;
1326		/* check response status */
1327		if (resp_msg->status != HTC_SERVICE_SUCCESS) {
1328			ath6kl_dbg(ATH6KL_DBG_HTC,
1329				   "Target failed service 0x%X connect request (status:%d)\n",
1330				   resp_msg->svc_id, resp_msg->status);
1331			status = -EINVAL;
1332			goto free_packet;
1333		}
1334
1335		assigned_epid = (enum htc_endpoint_id) resp_msg->eid;
1336		max_msg_size = le16_to_cpu(resp_msg->max_msg_sz);
1337	}
1338
1339	/* the rest are parameter checks so set the error status */
1340	status = -EINVAL;
1341
1342	if (assigned_epid >= ENDPOINT_MAX) {
1343		WARN_ON_ONCE(1);
1344		goto free_packet;
1345	}
1346
1347	if (max_msg_size == 0) {
1348		WARN_ON_ONCE(1);
1349		goto free_packet;
1350	}
1351
1352	ep = &target->endpoint[assigned_epid];
1353	ep->eid = assigned_epid;
1354	if (ep->svc_id != 0) {
1355		/* endpoint already in use! */
1356		WARN_ON_ONCE(1);
1357		goto free_packet;
1358	}
1359
1360	/* return assigned endpoint to caller */
1361	conn_resp->endpoint = assigned_epid;
1362	conn_resp->len_max = max_msg_size;
1363
1364	/* setup the endpoint */
1365	ep->svc_id = conn_req->svc_id; /* this marks ep in use */
1366	ep->max_txq_depth = conn_req->max_txq_depth;
1367	ep->len_max = max_msg_size;
1368	ep->cred_dist.credits = tx_alloc;
1369	ep->cred_dist.cred_sz = target->tgt_cred_sz;
1370	ep->cred_dist.cred_per_msg = max_msg_size / target->tgt_cred_sz;
1371	if (max_msg_size % target->tgt_cred_sz)
1372		ep->cred_dist.cred_per_msg++;
1373
1374	/* copy all the callbacks */
1375	ep->ep_cb = conn_req->ep_cb;
1376
1377	/* initialize tx_drop_packet_threshold */
1378	ep->tx_drop_packet_threshold = MAX_HI_COOKIE_NUM;
1379
1380	status = ath6kl_hif_pipe_map_service(ar, ep->svc_id,
1381					     &ep->pipe.pipeid_ul,
1382					     &ep->pipe.pipeid_dl);
1383	if (status != 0)
1384		goto free_packet;
1385
1386	ath6kl_dbg(ATH6KL_DBG_HTC,
1387		   "SVC Ready: 0x%4.4X: ULpipe:%d DLpipe:%d id:%d\n",
1388		   ep->svc_id, ep->pipe.pipeid_ul,
1389		   ep->pipe.pipeid_dl, ep->eid);
1390
1391	if (disable_credit_flowctrl && ep->pipe.tx_credit_flow_enabled) {
1392		ep->pipe.tx_credit_flow_enabled = false;
1393		ath6kl_dbg(ATH6KL_DBG_HTC,
1394			   "SVC: 0x%4.4X ep:%d TX flow control off\n",
1395			   ep->svc_id, assigned_epid);
1396	}
1397
1398free_packet:
1399	if (packet != NULL)
1400		htc_free_txctrl_packet(target, packet);
1401	return status;
1402}
1403
1404/* htc export functions */
1405static void *ath6kl_htc_pipe_create(struct ath6kl *ar)
1406{
1407	int status = 0;
1408	struct htc_endpoint *ep = NULL;
1409	struct htc_target *target = NULL;
1410	struct htc_packet *packet;
1411	int i;
1412
1413	target = kzalloc(sizeof(struct htc_target), GFP_KERNEL);
1414	if (target == NULL) {
1415		ath6kl_err("htc create unable to allocate memory\n");
1416		status = -ENOMEM;
1417		goto fail_htc_create;
1418	}
1419
1420	spin_lock_init(&target->htc_lock);
1421	spin_lock_init(&target->rx_lock);
1422	spin_lock_init(&target->tx_lock);
1423
1424	reset_endpoint_states(target);
1425
1426	for (i = 0; i < HTC_PACKET_CONTAINER_ALLOCATION; i++) {
1427		packet = kzalloc(sizeof(struct htc_packet), GFP_KERNEL);
1428
1429		if (packet != NULL)
1430			free_htc_packet_container(target, packet);
1431	}
1432
1433	target->dev = kzalloc(sizeof(*target->dev), GFP_KERNEL);
1434	if (!target->dev) {
1435		ath6kl_err("unable to allocate memory\n");
1436		status = -ENOMEM;
1437		goto fail_htc_create;
1438	}
1439	target->dev->ar = ar;
1440	target->dev->htc_cnxt = target;
1441
1442	/* Get HIF default pipe for HTC message exchange */
1443	ep = &target->endpoint[ENDPOINT_0];
1444
1445	ath6kl_hif_pipe_get_default(ar, &ep->pipe.pipeid_ul,
1446				    &ep->pipe.pipeid_dl);
1447
1448	return target;
1449
1450fail_htc_create:
1451	if (status != 0) {
1452		if (target != NULL)
1453			ath6kl_htc_pipe_cleanup(target);
1454
1455		target = NULL;
1456	}
1457	return target;
1458}
1459
1460/* cleanup the HTC instance */
1461static void ath6kl_htc_pipe_cleanup(struct htc_target *target)
1462{
1463	struct htc_packet *packet;
1464
1465	while (true) {
1466		packet = alloc_htc_packet_container(target);
1467		if (packet == NULL)
1468			break;
1469		kfree(packet);
1470	}
1471
1472	kfree(target->dev);
1473
1474	/* kfree our instance */
1475	kfree(target);
1476}
1477
1478static int ath6kl_htc_pipe_start(struct htc_target *target)
1479{
1480	struct sk_buff *skb;
1481	struct htc_setup_comp_ext_msg *setup;
1482	struct htc_packet *packet;
1483
1484	htc_config_target_hif_pipe(target);
1485
1486	/* allocate a buffer to send */
1487	packet = htc_alloc_txctrl_packet(target);
1488	if (packet == NULL) {
1489		WARN_ON_ONCE(1);
1490		return -ENOMEM;
1491	}
1492
1493	skb = packet->skb;
1494
1495	/* assemble setup complete message */
1496	setup = skb_put(skb, sizeof(*setup));
1497	memset(setup, 0, sizeof(struct htc_setup_comp_ext_msg));
1498	setup->msg_id = cpu_to_le16(HTC_MSG_SETUP_COMPLETE_EX_ID);
1499
1500	ath6kl_dbg(ATH6KL_DBG_HTC, "HTC using TX credit flow control\n");
1501
1502	set_htc_pkt_info(packet, NULL, (u8 *) setup,
1503			 sizeof(struct htc_setup_comp_ext_msg),
1504			 ENDPOINT_0, HTC_SERVICE_TX_PACKET_TAG);
1505
1506	target->htc_flags |= HTC_OP_STATE_SETUP_COMPLETE;
1507
1508	return ath6kl_htc_pipe_tx(target, packet);
1509}
1510
1511static void ath6kl_htc_pipe_stop(struct htc_target *target)
1512{
1513	int i;
1514	struct htc_endpoint *ep;
1515
1516	/* cleanup endpoints */
1517	for (i = 0; i < ENDPOINT_MAX; i++) {
1518		ep = &target->endpoint[i];
1519		htc_flush_rx_queue(target, ep);
1520		htc_flush_tx_endpoint(target, ep, HTC_TX_PACKET_TAG_ALL);
1521	}
1522
1523	reset_endpoint_states(target);
1524	target->htc_flags &= ~HTC_OP_STATE_SETUP_COMPLETE;
1525}
1526
1527static int ath6kl_htc_pipe_get_rxbuf_num(struct htc_target *target,
1528					 enum htc_endpoint_id endpoint)
1529{
1530	int num;
1531
1532	spin_lock_bh(&target->rx_lock);
1533	num = get_queue_depth(&(target->endpoint[endpoint].rx_bufq));
1534	spin_unlock_bh(&target->rx_lock);
1535
1536	return num;
1537}
1538
1539static int ath6kl_htc_pipe_tx(struct htc_target *target,
1540			      struct htc_packet *packet)
1541{
1542	struct list_head queue;
1543
1544	ath6kl_dbg(ATH6KL_DBG_HTC,
1545		   "%s: endPointId: %d, buffer: 0x%p, length: %d\n",
1546		   __func__, packet->endpoint, packet->buf,
1547		   packet->act_len);
1548
1549	INIT_LIST_HEAD(&queue);
1550	list_add_tail(&packet->list, &queue);
1551
1552	return htc_send_packets_multiple(target, &queue);
1553}
1554
1555static int ath6kl_htc_pipe_wait_target(struct htc_target *target)
1556{
1557	struct htc_ready_ext_msg *ready_msg;
1558	struct htc_service_connect_req connect;
1559	struct htc_service_connect_resp resp;
1560	int status = 0;
1561
1562	status = htc_wait_recv_ctrl_message(target);
1563
1564	if (status != 0)
1565		return status;
1566
1567	if (target->pipe.ctrl_response_len < sizeof(*ready_msg)) {
1568		ath6kl_warn("invalid htc pipe ready msg len: %d\n",
1569			    target->pipe.ctrl_response_len);
1570		return -ECOMM;
1571	}
1572
1573	ready_msg = (struct htc_ready_ext_msg *) target->pipe.ctrl_response_buf;
1574
1575	if (ready_msg->ver2_0_info.msg_id != cpu_to_le16(HTC_MSG_READY_ID)) {
1576		ath6kl_warn("invalid htc pipe ready msg: 0x%x\n",
1577			    ready_msg->ver2_0_info.msg_id);
1578		return -ECOMM;
1579	}
1580
1581	ath6kl_dbg(ATH6KL_DBG_HTC,
1582		   "Target Ready! : transmit resources : %d size:%d\n",
1583		   ready_msg->ver2_0_info.cred_cnt,
1584		   ready_msg->ver2_0_info.cred_sz);
1585
1586	target->tgt_creds = le16_to_cpu(ready_msg->ver2_0_info.cred_cnt);
1587	target->tgt_cred_sz = le16_to_cpu(ready_msg->ver2_0_info.cred_sz);
1588
1589	if ((target->tgt_creds == 0) || (target->tgt_cred_sz == 0))
1590		return -ECOMM;
1591
1592	htc_setup_target_buffer_assignments(target);
1593
1594	/* setup our pseudo HTC control endpoint connection */
1595	memset(&connect, 0, sizeof(connect));
1596	memset(&resp, 0, sizeof(resp));
1597	connect.ep_cb.tx_complete = htc_txctrl_complete;
1598	connect.ep_cb.rx = htc_rxctrl_complete;
1599	connect.max_txq_depth = NUM_CONTROL_TX_BUFFERS;
1600	connect.svc_id = HTC_CTRL_RSVD_SVC;
1601
1602	/* connect fake service */
1603	status = ath6kl_htc_pipe_conn_service(target, &connect, &resp);
1604
1605	return status;
1606}
1607
1608static void ath6kl_htc_pipe_flush_txep(struct htc_target *target,
1609				       enum htc_endpoint_id endpoint, u16 tag)
1610{
1611	struct htc_endpoint *ep = &target->endpoint[endpoint];
1612
1613	if (ep->svc_id == 0) {
1614		WARN_ON_ONCE(1);
1615		/* not in use.. */
1616		return;
1617	}
1618
1619	htc_flush_tx_endpoint(target, ep, tag);
1620}
1621
1622static int ath6kl_htc_pipe_add_rxbuf_multiple(struct htc_target *target,
1623					      struct list_head *pkt_queue)
1624{
1625	struct htc_packet *packet, *tmp_pkt, *first;
1626	struct htc_endpoint *ep;
1627	int status = 0;
1628
1629	if (list_empty(pkt_queue))
1630		return -EINVAL;
1631
1632	first = list_first_entry(pkt_queue, struct htc_packet, list);
1633
1634	if (first->endpoint >= ENDPOINT_MAX) {
1635		WARN_ON_ONCE(1);
1636		return -EINVAL;
1637	}
1638
1639	ath6kl_dbg(ATH6KL_DBG_HTC, "%s: epid: %d, cnt:%d, len: %d\n",
1640		   __func__, first->endpoint, get_queue_depth(pkt_queue),
1641		   first->buf_len);
1642
1643	ep = &target->endpoint[first->endpoint];
1644
1645	spin_lock_bh(&target->rx_lock);
1646
1647	/* store receive packets */
1648	list_splice_tail_init(pkt_queue, &ep->rx_bufq);
1649
1650	spin_unlock_bh(&target->rx_lock);
1651
1652	if (status != 0) {
1653		/* walk through queue and mark each one canceled */
1654		list_for_each_entry_safe(packet, tmp_pkt, pkt_queue, list) {
1655			packet->status = -ECANCELED;
1656		}
1657
1658		do_recv_completion(ep, pkt_queue);
1659	}
1660
1661	return status;
1662}
1663
1664static void ath6kl_htc_pipe_activity_changed(struct htc_target *target,
1665					     enum htc_endpoint_id ep,
1666					     bool active)
1667{
1668	/* TODO */
1669}
1670
1671static void ath6kl_htc_pipe_flush_rx_buf(struct htc_target *target)
1672{
1673	struct htc_endpoint *endpoint;
1674	struct htc_packet *packet, *tmp_pkt;
1675	int i;
1676
1677	for (i = ENDPOINT_0; i < ENDPOINT_MAX; i++) {
1678		endpoint = &target->endpoint[i];
1679
1680		spin_lock_bh(&target->rx_lock);
1681
1682		list_for_each_entry_safe(packet, tmp_pkt,
1683					 &endpoint->rx_bufq, list) {
1684			list_del(&packet->list);
1685			spin_unlock_bh(&target->rx_lock);
1686			ath6kl_dbg(ATH6KL_DBG_HTC,
1687				   "htc rx flush pkt 0x%p len %d ep %d\n",
1688				   packet, packet->buf_len,
1689				   packet->endpoint);
1690			dev_kfree_skb(packet->pkt_cntxt);
1691			spin_lock_bh(&target->rx_lock);
1692		}
1693
1694		spin_unlock_bh(&target->rx_lock);
1695	}
1696}
1697
1698static int ath6kl_htc_pipe_credit_setup(struct htc_target *target,
1699					struct ath6kl_htc_credit_info *info)
1700{
1701	return 0;
1702}
1703
1704static const struct ath6kl_htc_ops ath6kl_htc_pipe_ops = {
1705	.create = ath6kl_htc_pipe_create,
1706	.wait_target = ath6kl_htc_pipe_wait_target,
1707	.start = ath6kl_htc_pipe_start,
1708	.conn_service = ath6kl_htc_pipe_conn_service,
1709	.tx = ath6kl_htc_pipe_tx,
1710	.stop = ath6kl_htc_pipe_stop,
1711	.cleanup = ath6kl_htc_pipe_cleanup,
1712	.flush_txep = ath6kl_htc_pipe_flush_txep,
1713	.flush_rx_buf = ath6kl_htc_pipe_flush_rx_buf,
1714	.activity_changed = ath6kl_htc_pipe_activity_changed,
1715	.get_rxbuf_num = ath6kl_htc_pipe_get_rxbuf_num,
1716	.add_rxbuf_multiple = ath6kl_htc_pipe_add_rxbuf_multiple,
1717	.credit_setup = ath6kl_htc_pipe_credit_setup,
1718	.tx_complete = ath6kl_htc_pipe_tx_complete,
1719	.rx_complete = ath6kl_htc_pipe_rx_complete,
1720};
1721
1722void ath6kl_htc_pipe_attach(struct ath6kl *ar)
1723{
1724	ar->htc_ops = &ath6kl_htc_pipe_ops;
1725}
1726