/*
   * Copyright (c) 2007-2011 Atheros Communications Inc.
   * Copyright (c) 2011-2012 Qualcomm Atheros, Inc.
   *
   * Permission to use, copy, modify, and/or distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include "core.h"
  #include "hif.h"
  #include "debug.h"
  #include "hif-ops.h"
  #include "trace.h"
  
  #include <asm/unaligned.h>
  
  #define CALC_TXRX_PADDED_LEN(dev, len)  (__ALIGN_MASK((len), (dev)->block_mask))
  
  static void ath6kl_htc_mbox_cleanup(struct htc_target *target);
  static void ath6kl_htc_mbox_stop(struct htc_target *target);
  static int ath6kl_htc_mbox_add_rxbuf_multiple(struct htc_target *target,
  					      struct list_head *pkt_queue);
  static void ath6kl_htc_set_credit_dist(struct htc_target *target,
  				       struct ath6kl_htc_credit_info *cred_info,
  				       u16 svc_pri_order[], int len);
  
  /* threshold to re-enable Tx bundling for an AC*/
  #define TX_RESUME_BUNDLE_THRESHOLD	1500
  
  /* Functions for Tx credit handling */
  static void ath6kl_credit_deposit(struct ath6kl_htc_credit_info *cred_info,
  				  struct htc_endpoint_credit_dist *ep_dist,
  				  int credits)
  {
  	ath6kl_dbg(ATH6KL_DBG_CREDIT, "credit deposit ep %d credits %d
  ",
  		   ep_dist->endpoint, credits);
  
  	ep_dist->credits += credits;
  	ep_dist->cred_assngd += credits;
  	cred_info->cur_free_credits -= credits;
  }
  
  static void ath6kl_credit_init(struct ath6kl_htc_credit_info *cred_info,
  			       struct list_head *ep_list,
  			       int tot_credits)
  {
  	struct htc_endpoint_credit_dist *cur_ep_dist;
  	int count;
  
  	ath6kl_dbg(ATH6KL_DBG_CREDIT, "credit init total %d
  ", tot_credits);
  
  	cred_info->cur_free_credits = tot_credits;
  	cred_info->total_avail_credits = tot_credits;
  
  	list_for_each_entry(cur_ep_dist, ep_list, list) {
  		if (cur_ep_dist->endpoint == ENDPOINT_0)
  			continue;
  
  		cur_ep_dist->cred_min = cur_ep_dist->cred_per_msg;
  
  		if (tot_credits > 4) {
  			if ((cur_ep_dist->svc_id == WMI_DATA_BK_SVC) ||
  			    (cur_ep_dist->svc_id == WMI_DATA_BE_SVC)) {
  				ath6kl_credit_deposit(cred_info,
  						      cur_ep_dist,
  						      cur_ep_dist->cred_min);
  				cur_ep_dist->dist_flags |= HTC_EP_ACTIVE;
  			}
  		}
  
  		if (cur_ep_dist->svc_id == WMI_CONTROL_SVC) {
  			ath6kl_credit_deposit(cred_info, cur_ep_dist,
  					      cur_ep_dist->cred_min);
  			/*
  			 * Control service is always marked active, it
  			 * never goes inactive EVER.
  			 */
  			cur_ep_dist->dist_flags |= HTC_EP_ACTIVE;
  		}
  
  		/*
  		 * Streams have to be created (explicit | implicit) for all
  		 * kinds of traffic. BE endpoints are also inactive in the
  		 * beginning. When BE traffic starts it creates implicit
  		 * streams that redistributes credits.
  		 *
  		 * Note: all other endpoints have minimums set but are
  		 * initially given NO credits. credits will be distributed
  		 * as traffic activity demands
  		 */
  	}
  
  	/*
  	 * For ath6kl_credit_seek function,
  	 * it use list_for_each_entry_reverse to walk around the whole ep list.
  	 * Therefore assign this lowestpri_ep_dist after walk around the ep_list
  	 */
  	cred_info->lowestpri_ep_dist = cur_ep_dist->list;
  
  	WARN_ON(cred_info->cur_free_credits <= 0);
  
  	list_for_each_entry(cur_ep_dist, ep_list, list) {
  		if (cur_ep_dist->endpoint == ENDPOINT_0)
  			continue;
  
  		if (cur_ep_dist->svc_id == WMI_CONTROL_SVC) {
  			cur_ep_dist->cred_norm = cur_ep_dist->cred_per_msg;
  		} else {
  			/*
  			 * For the remaining data endpoints, we assume that
  			 * each cred_per_msg are the same. We use a simple
  			 * calculation here, we take the remaining credits
  			 * and determine how many max messages this can
  			 * cover and then set each endpoint's normal value
  			 * equal to 3/4 this amount.
  			 */
  			count = (cred_info->cur_free_credits /
  				 cur_ep_dist->cred_per_msg)
  				* cur_ep_dist->cred_per_msg;
  			count = (count * 3) >> 2;
  			count = max(count, cur_ep_dist->cred_per_msg);
  			cur_ep_dist->cred_norm = count;
  		}
  
  		ath6kl_dbg(ATH6KL_DBG_CREDIT,
  			   "credit ep %d svc_id %d credits %d per_msg %d norm %d min %d
  ",
  			   cur_ep_dist->endpoint,
  			   cur_ep_dist->svc_id,
  			   cur_ep_dist->credits,
  			   cur_ep_dist->cred_per_msg,
  			   cur_ep_dist->cred_norm,
  			   cur_ep_dist->cred_min);
  	}
  }
  
  /* initialize and setup credit distribution */
  static int ath6kl_htc_mbox_credit_setup(struct htc_target *htc_target,
  			       struct ath6kl_htc_credit_info *cred_info)
  {
  	u16 servicepriority[5];
  
  	memset(cred_info, 0, sizeof(struct ath6kl_htc_credit_info));
  
  	servicepriority[0] = WMI_CONTROL_SVC;  /* highest */
  	servicepriority[1] = WMI_DATA_VO_SVC;
  	servicepriority[2] = WMI_DATA_VI_SVC;
  	servicepriority[3] = WMI_DATA_BE_SVC;
  	servicepriority[4] = WMI_DATA_BK_SVC; /* lowest */
  
  	/* set priority list */
  	ath6kl_htc_set_credit_dist(htc_target, cred_info, servicepriority, 5);
  
  	return 0;
  }
  
  /* reduce an ep's credits back to a set limit */
  static void ath6kl_credit_reduce(struct ath6kl_htc_credit_info *cred_info,
  				 struct htc_endpoint_credit_dist *ep_dist,
  				 int limit)
  {
  	int credits;
  
  	ath6kl_dbg(ATH6KL_DBG_CREDIT, "credit reduce ep %d limit %d
  ",
  		   ep_dist->endpoint, limit);
  
  	ep_dist->cred_assngd = limit;
  
  	if (ep_dist->credits <= limit)
  		return;
  
  	credits = ep_dist->credits - limit;
  	ep_dist->credits -= credits;
  	cred_info->cur_free_credits += credits;
  }
  
  static void ath6kl_credit_update(struct ath6kl_htc_credit_info *cred_info,
  				 struct list_head *epdist_list)
  {
  	struct htc_endpoint_credit_dist *cur_list;
  
  	list_for_each_entry(cur_list, epdist_list, list) {
  		if (cur_list->endpoint == ENDPOINT_0)
  			continue;
  
  		if (cur_list->cred_to_dist > 0) {
  			cur_list->credits += cur_list->cred_to_dist;
  			cur_list->cred_to_dist = 0;
  
  			if (cur_list->credits > cur_list->cred_assngd)
  				ath6kl_credit_reduce(cred_info,
  						     cur_list,
  						     cur_list->cred_assngd);
  
  			if (cur_list->credits > cur_list->cred_norm)
  				ath6kl_credit_reduce(cred_info, cur_list,
  						     cur_list->cred_norm);
  
  			if (!(cur_list->dist_flags & HTC_EP_ACTIVE)) {
  				if (cur_list->txq_depth == 0)
  					ath6kl_credit_reduce(cred_info,
  							     cur_list, 0);
  			}
  		}
  	}
  }
  
  /*
   * HTC has an endpoint that needs credits, ep_dist is the endpoint in
   * question.
   */
  static void ath6kl_credit_seek(struct ath6kl_htc_credit_info *cred_info,
  				struct htc_endpoint_credit_dist *ep_dist)
  {
  	struct htc_endpoint_credit_dist *curdist_list;
  	int credits = 0;
  	int need;
  
  	if (ep_dist->svc_id == WMI_CONTROL_SVC)
  		goto out;
  
  	if ((ep_dist->svc_id == WMI_DATA_VI_SVC) ||
  	    (ep_dist->svc_id == WMI_DATA_VO_SVC))
  		if ((ep_dist->cred_assngd >= ep_dist->cred_norm))
  			goto out;
  
  	/*
  	 * For all other services, we follow a simple algorithm of:
  	 *
  	 * 1. checking the free pool for credits
  	 * 2. checking lower priority endpoints for credits to take
  	 */
  
  	credits = min(cred_info->cur_free_credits, ep_dist->seek_cred);
  
  	if (credits >= ep_dist->seek_cred)
  		goto out;
  
  	/*
  	 * We don't have enough in the free pool, try taking away from
  	 * lower priority services The rule for taking away credits:
  	 *
  	 *   1. Only take from lower priority endpoints
  	 *   2. Only take what is allocated above the minimum (never
  	 *      starve an endpoint completely)
  	 *   3. Only take what you need.
  	 */
  
  	list_for_each_entry_reverse(curdist_list,
  				    &cred_info->lowestpri_ep_dist,
  				    list) {
  		if (curdist_list == ep_dist)
  			break;
  
  		need = ep_dist->seek_cred - cred_info->cur_free_credits;
  
  		if ((curdist_list->cred_assngd - need) >=
  		     curdist_list->cred_min) {
  			/*
  			 * The current one has been allocated more than
  			 * it's minimum and it has enough credits assigned
  			 * above it's minimum to fulfill our need try to
  			 * take away just enough to fulfill our need.
  			 */
  			ath6kl_credit_reduce(cred_info, curdist_list,
  					     curdist_list->cred_assngd - need);
  
  			if (cred_info->cur_free_credits >=
  			    ep_dist->seek_cred)
  				break;
  		}
  
  		if (curdist_list->endpoint == ENDPOINT_0)
  			break;
  	}
  
  	credits = min(cred_info->cur_free_credits, ep_dist->seek_cred);
  
  out:
  	/* did we find some credits? */
  	if (credits)
  		ath6kl_credit_deposit(cred_info, ep_dist, credits);
  
  	ep_dist->seek_cred = 0;
  }
  
  /* redistribute credits based on activity change */
  static void ath6kl_credit_redistribute(struct ath6kl_htc_credit_info *info,
  				       struct list_head *ep_dist_list)
  {
  	struct htc_endpoint_credit_dist *curdist_list;
  
  	list_for_each_entry(curdist_list, ep_dist_list, list) {
  		if (curdist_list->endpoint == ENDPOINT_0)
  			continue;
  
  		if ((curdist_list->svc_id == WMI_DATA_BK_SVC)  ||
  		    (curdist_list->svc_id == WMI_DATA_BE_SVC))
  			curdist_list->dist_flags |= HTC_EP_ACTIVE;
  
  		if ((curdist_list->svc_id != WMI_CONTROL_SVC) &&
  		    !(curdist_list->dist_flags & HTC_EP_ACTIVE)) {
  			if (curdist_list->txq_depth == 0)
  				ath6kl_credit_reduce(info, curdist_list, 0);
  			else
  				ath6kl_credit_reduce(info,
  						     curdist_list,
  						     curdist_list->cred_min);
  		}
  	}
  }
  
  /*
   *
   * This function is invoked whenever endpoints require credit
   * distributions. A lock is held while this function is invoked, this
   * function shall NOT block. The ep_dist_list is a list of distribution
   * structures in prioritized order as defined by the call to the
   * htc_set_credit_dist() api.
   */
  static void ath6kl_credit_distribute(struct ath6kl_htc_credit_info *cred_info,
  				     struct list_head *ep_dist_list,
  			      enum htc_credit_dist_reason reason)
  {
  	switch (reason) {
  	case HTC_CREDIT_DIST_SEND_COMPLETE:
  		ath6kl_credit_update(cred_info, ep_dist_list);
  		break;
  	case HTC_CREDIT_DIST_ACTIVITY_CHANGE:
  		ath6kl_credit_redistribute(cred_info, ep_dist_list);
  		break;
  	default:
  		break;
  	}
  
  	WARN_ON(cred_info->cur_free_credits > cred_info->total_avail_credits);
  	WARN_ON(cred_info->cur_free_credits < 0);
  }
  
  static void ath6kl_htc_tx_buf_align(u8 **buf, unsigned long len)
  {
  	u8 *align_addr;
  
  	if (!IS_ALIGNED((unsigned long) *buf, 4)) {
  		align_addr = PTR_ALIGN(*buf - 4, 4);
  		memmove(align_addr, *buf, len);
  		*buf = align_addr;
  	}
  }
  
  static void ath6kl_htc_tx_prep_pkt(struct htc_packet *packet, u8 flags,
  				   int ctrl0, int ctrl1)
  {
  	struct htc_frame_hdr *hdr;
  
  	packet->buf -= HTC_HDR_LENGTH;
  	hdr =  (struct htc_frame_hdr *)packet->buf;
  
  	/* Endianess? */
  	put_unaligned((u16)packet->act_len, &hdr->payld_len);
  	hdr->flags = flags;
  	hdr->eid = packet->endpoint;
  	hdr->ctrl[0] = ctrl0;
  	hdr->ctrl[1] = ctrl1;
  }
  
  static void htc_reclaim_txctrl_buf(struct htc_target *target,
  				   struct htc_packet *pkt)
  {
  	spin_lock_bh(&target->htc_lock);
  	list_add_tail(&pkt->list, &target->free_ctrl_txbuf);
  	spin_unlock_bh(&target->htc_lock);
  }
  
  static struct htc_packet *htc_get_control_buf(struct htc_target *target,
  					      bool tx)
  {
  	struct htc_packet *packet = NULL;
  	struct list_head *buf_list;
  
  	buf_list = tx ? &target->free_ctrl_txbuf : &target->free_ctrl_rxbuf;
  
  	spin_lock_bh(&target->htc_lock);
  
  	if (list_empty(buf_list)) {
  		spin_unlock_bh(&target->htc_lock);
  		return NULL;
  	}
  
  	packet = list_first_entry(buf_list, struct htc_packet, list);
  	list_del(&packet->list);
  	spin_unlock_bh(&target->htc_lock);
  
  	if (tx)
  		packet->buf = packet->buf_start + HTC_HDR_LENGTH;
  
  	return packet;
  }
  
  static void htc_tx_comp_update(struct htc_target *target,
  			       struct htc_endpoint *endpoint,
  			       struct htc_packet *packet)
  {
  	packet->completion = NULL;
  	packet->buf += HTC_HDR_LENGTH;
  
  	if (!packet->status)
  		return;
  
  	ath6kl_err("req failed (status:%d, ep:%d, len:%d creds:%d)
  ",
  		   packet->status, packet->endpoint, packet->act_len,
  		   packet->info.tx.cred_used);
  
  	/* on failure to submit, reclaim credits for this packet */
  	spin_lock_bh(&target->tx_lock);
  	endpoint->cred_dist.cred_to_dist +=
  				packet->info.tx.cred_used;
  	endpoint->cred_dist.txq_depth = get_queue_depth(&endpoint->txq);
  
  	ath6kl_dbg(ATH6KL_DBG_HTC, "htc tx ctxt 0x%p dist 0x%p
  ",
  		   target->credit_info, &target->cred_dist_list);
  
  	ath6kl_credit_distribute(target->credit_info,
  				 &target->cred_dist_list,
  				 HTC_CREDIT_DIST_SEND_COMPLETE);
  
  	spin_unlock_bh(&target->tx_lock);
  }
  
  static void htc_tx_complete(struct htc_endpoint *endpoint,
  			    struct list_head *txq)
  {
  	if (list_empty(txq))
  		return;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc tx complete ep %d pkts %d
  ",
  		   endpoint->eid, get_queue_depth(txq));
  
  	ath6kl_tx_complete(endpoint->target, txq);
  }
  
  static void htc_tx_comp_handler(struct htc_target *target,
  				struct htc_packet *packet)
  {
  	struct htc_endpoint *endpoint = &target->endpoint[packet->endpoint];
  	struct list_head container;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC, "htc tx complete seqno %d
  ",
  		   packet->info.tx.seqno);
  
  	htc_tx_comp_update(target, endpoint, packet);
  	INIT_LIST_HEAD(&container);
  	list_add_tail(&packet->list, &container);
  	/* do completion */
  	htc_tx_complete(endpoint, &container);
  }
  
  static void htc_async_tx_scat_complete(struct htc_target *target,
  				       struct hif_scatter_req *scat_req)
  {
  	struct htc_endpoint *endpoint;
  	struct htc_packet *packet;
  	struct list_head tx_compq;
  	int i;
  
  	INIT_LIST_HEAD(&tx_compq);
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc tx scat complete len %d entries %d
  ",
  		   scat_req->len, scat_req->scat_entries);
  
  	if (scat_req->status)
  		ath6kl_err("send scatter req failed: %d
  ", scat_req->status);
  
  	packet = scat_req->scat_list[0].packet;
  	endpoint = &target->endpoint[packet->endpoint];
  
  	/* walk through the scatter list and process */
  	for (i = 0; i < scat_req->scat_entries; i++) {
  		packet = scat_req->scat_list[i].packet;
  		if (!packet) {
  			WARN_ON(1);
  			return;
  		}
  
  		packet->status = scat_req->status;
  		htc_tx_comp_update(target, endpoint, packet);
  		list_add_tail(&packet->list, &tx_compq);
  	}
  
  	/* free scatter request */
  	hif_scatter_req_add(target->dev->ar, scat_req);
  
  	/* complete all packets */
  	htc_tx_complete(endpoint, &tx_compq);
  }
  
  static int ath6kl_htc_tx_issue(struct htc_target *target,
  			       struct htc_packet *packet)
  {
  	int status;
  	bool sync = false;
  	u32 padded_len, send_len;
  
  	if (!packet->completion)
  		sync = true;
  
  	send_len = packet->act_len + HTC_HDR_LENGTH;
  
  	padded_len = CALC_TXRX_PADDED_LEN(target, send_len);
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc tx issue len %d seqno %d padded_len %d mbox 0x%X %s
  ",
  		   send_len, packet->info.tx.seqno, padded_len,
  		   target->dev->ar->mbox_info.htc_addr,
  		   sync ? "sync" : "async");
  
  	if (sync) {
  		status = hif_read_write_sync(target->dev->ar,
  				target->dev->ar->mbox_info.htc_addr,
  				 packet->buf, padded_len,
  				 HIF_WR_SYNC_BLOCK_INC);
  
  		packet->status = status;
  		packet->buf += HTC_HDR_LENGTH;
  	} else
  		status = hif_write_async(target->dev->ar,
  				target->dev->ar->mbox_info.htc_addr,
  				packet->buf, padded_len,
  				HIF_WR_ASYNC_BLOCK_INC, packet);
  
  	trace_ath6kl_htc_tx(status, packet->endpoint, packet->buf, send_len);
  
  	return status;
  }
  
  static int htc_check_credits(struct htc_target *target,
  			     struct htc_endpoint *ep, u8 *flags,
  			     enum htc_endpoint_id eid, unsigned int len,
  			     int *req_cred)
  {
  	*req_cred = (len > target->tgt_cred_sz) ?
  		     DIV_ROUND_UP(len, target->tgt_cred_sz) : 1;
  
  	ath6kl_dbg(ATH6KL_DBG_CREDIT, "credit check need %d got %d
  ",
  		   *req_cred, ep->cred_dist.credits);
  
  	if (ep->cred_dist.credits < *req_cred) {
  		if (eid == ENDPOINT_0)
  			return -EINVAL;
  
  		/* Seek more credits */
  		ep->cred_dist.seek_cred = *req_cred - ep->cred_dist.credits;
  
  		ath6kl_credit_seek(target->credit_info, &ep->cred_dist);
  
  		ep->cred_dist.seek_cred = 0;
  
  		if (ep->cred_dist.credits < *req_cred) {
  			ath6kl_dbg(ATH6KL_DBG_CREDIT,
  				   "credit not found for ep %d
  ",
  				   eid);
  			return -EINVAL;
  		}
  	}
  
  	ep->cred_dist.credits -= *req_cred;
  	ep->ep_st.cred_cosumd += *req_cred;
  
  	 /* When we are getting low on credits, ask for more */
  	if (ep->cred_dist.credits < ep->cred_dist.cred_per_msg) {
  		ep->cred_dist.seek_cred =
  		ep->cred_dist.cred_per_msg - ep->cred_dist.credits;
  
  		ath6kl_credit_seek(target->credit_info, &ep->cred_dist);
  
  		/* see if we were successful in getting more */
  		if (ep->cred_dist.credits < ep->cred_dist.cred_per_msg) {
  			/* tell the target we need credits ASAP! */
  			*flags |= HTC_FLAGS_NEED_CREDIT_UPDATE;
  			ep->ep_st.cred_low_indicate += 1;
  			ath6kl_dbg(ATH6KL_DBG_CREDIT,
  				   "credit we need credits asap
  ");
  		}
  	}
  
  	return 0;
  }
  
  static void ath6kl_htc_tx_pkts_get(struct htc_target *target,
  				   struct htc_endpoint *endpoint,
  				   struct list_head *queue)
  {
  	int req_cred;
  	u8 flags;
  	struct htc_packet *packet;
  	unsigned int len;
  
  	while (true) {
  		flags = 0;
  
  		if (list_empty(&endpoint->txq))
  			break;
  		packet = list_first_entry(&endpoint->txq, struct htc_packet,
  					  list);
  
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc tx got packet 0x%p queue depth %d
  ",
  			   packet, get_queue_depth(&endpoint->txq));
  
  		len = CALC_TXRX_PADDED_LEN(target,
  					   packet->act_len + HTC_HDR_LENGTH);
  
  		if (htc_check_credits(target, endpoint, &flags,
  				      packet->endpoint, len, &req_cred))
  			break;
  
  		/* now we can fully move onto caller's queue */
  		packet = list_first_entry(&endpoint->txq, struct htc_packet,
  					  list);
  		list_move_tail(&packet->list, queue);
  
  		/* save the number of credits this packet consumed */
  		packet->info.tx.cred_used = req_cred;
  
  		/* all TX packets are handled asynchronously */
  		packet->completion = htc_tx_comp_handler;
  		packet->context = target;
  		endpoint->ep_st.tx_issued += 1;
  
  		/* save send flags */
  		packet->info.tx.flags = flags;
  		packet->info.tx.seqno = endpoint->seqno;
  		endpoint->seqno++;
  	}
  }
  
  /* See if the padded tx length falls on a credit boundary */
  static int htc_get_credit_padding(unsigned int cred_sz, int *len,
  				  struct htc_endpoint *ep)
  {
  	int rem_cred, cred_pad;
  
  	rem_cred = *len % cred_sz;
  
  	/* No padding needed */
  	if  (!rem_cred)
  		return 0;
  
  	if (!(ep->conn_flags & HTC_FLGS_TX_BNDL_PAD_EN))
  		return -1;
  
  	/*
  	 * The transfer consumes a "partial" credit, this
  	 * packet cannot be bundled unless we add
  	 * additional "dummy" padding (max 255 bytes) to
  	 * consume the entire credit.
  	 */
  	cred_pad = *len < cred_sz ? (cred_sz - *len) : rem_cred;
  
  	if ((cred_pad > 0) && (cred_pad <= 255))
  		*len += cred_pad;
  	else
  		/* The amount of padding is too large, send as non-bundled */
  		return -1;
  
  	return cred_pad;
  }
  
  static int ath6kl_htc_tx_setup_scat_list(struct htc_target *target,
  					 struct htc_endpoint *endpoint,
  					 struct hif_scatter_req *scat_req,
  					 int n_scat,
  					 struct list_head *queue)
  {
  	struct htc_packet *packet;
  	int i, len, rem_scat, cred_pad;
  	int status = 0;
  	u8 flags;
  
  	rem_scat = target->max_tx_bndl_sz;
  
  	for (i = 0; i < n_scat; i++) {
  		scat_req->scat_list[i].packet = NULL;
  
  		if (list_empty(queue))
  			break;
  
  		packet = list_first_entry(queue, struct htc_packet, list);
  		len = CALC_TXRX_PADDED_LEN(target,
  					   packet->act_len + HTC_HDR_LENGTH);
  
  		cred_pad = htc_get_credit_padding(target->tgt_cred_sz,
  						  &len, endpoint);
  		if (cred_pad < 0 || rem_scat < len) {
  			status = -ENOSPC;
  			break;
  		}
  
  		rem_scat -= len;
  		/* now remove it from the queue */
  		list_del(&packet->list);
  
  		scat_req->scat_list[i].packet = packet;
  		/* prepare packet and flag message as part of a send bundle */
  		flags = packet->info.tx.flags | HTC_FLAGS_SEND_BUNDLE;
  		ath6kl_htc_tx_prep_pkt(packet, flags,
  				       cred_pad, packet->info.tx.seqno);
  		/* Make sure the buffer is 4-byte aligned */
  		ath6kl_htc_tx_buf_align(&packet->buf,
  					packet->act_len + HTC_HDR_LENGTH);
  		scat_req->scat_list[i].buf = packet->buf;
  		scat_req->scat_list[i].len = len;
  
  		scat_req->len += len;
  		scat_req->scat_entries++;
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc tx adding (%d) pkt 0x%p seqno %d len %d remaining %d
  ",
  			   i, packet, packet->info.tx.seqno, len, rem_scat);
  	}
  
  	/* Roll back scatter setup in case of any failure */
  	if (scat_req->scat_entries < HTC_MIN_HTC_MSGS_TO_BUNDLE) {
  		for (i = scat_req->scat_entries - 1; i >= 0; i--) {
  			packet = scat_req->scat_list[i].packet;
  			if (packet) {
  				packet->buf += HTC_HDR_LENGTH;
  				list_add(&packet->list, queue);
  			}
  		}
  		return -EAGAIN;
  	}
  
  	return status;
  }
  
  /*
   * Drain a queue and send as bundles this function may return without fully
   * draining the queue when
   *
   *    1. scatter resources are exhausted
   *    2. a message that will consume a partial credit will stop the
   *    bundling process early
   *    3. we drop below the minimum number of messages for a bundle
   */
  static void ath6kl_htc_tx_bundle(struct htc_endpoint *endpoint,
  				 struct list_head *queue,
  				 int *sent_bundle, int *n_bundle_pkts)
  {
  	struct htc_target *target = endpoint->target;
  	struct hif_scatter_req *scat_req = NULL;
  	int n_scat, n_sent_bundle = 0, tot_pkts_bundle = 0, i;
  	struct htc_packet *packet;
  	int status;
  	u32 txb_mask;
  	u8 ac = WMM_NUM_AC;
  
  	if ((HTC_CTRL_RSVD_SVC != endpoint->svc_id) &&
  	    (WMI_CONTROL_SVC != endpoint->svc_id))
  		ac = target->dev->ar->ep2ac_map[endpoint->eid];
  
  	while (true) {
  		status = 0;
  		n_scat = get_queue_depth(queue);
  		n_scat = min(n_scat, target->msg_per_bndl_max);
  
  		if (n_scat < HTC_MIN_HTC_MSGS_TO_BUNDLE)
  			/* not enough to bundle */
  			break;
  
  		scat_req = hif_scatter_req_get(target->dev->ar);
  
  		if (!scat_req) {
  			/* no scatter resources  */
  			ath6kl_dbg(ATH6KL_DBG_HTC,
  				   "htc tx no more scatter resources
  ");
  			break;
  		}
  
  		if ((ac < WMM_NUM_AC) && (ac != WMM_AC_BK)) {
  			if (WMM_AC_BE == ac)
  				/*
  				 * BE, BK have priorities and bit
  				 * positions reversed
  				 */
  				txb_mask = (1 << WMM_AC_BK);
  			else
  				/*
  				 * any AC with priority lower than
  				 * itself
  				 */
  				txb_mask = ((1 << ac) - 1);
  
  			/*
  			 * when the scatter request resources drop below a
  			 * certain threshold, disable Tx bundling for all
  			 * AC's with priority lower than the current requesting
  			 * AC. Otherwise re-enable Tx bundling for them
  			 */
  			if (scat_req->scat_q_depth < ATH6KL_SCATTER_REQS)
  				target->tx_bndl_mask &= ~txb_mask;
  			else
  				target->tx_bndl_mask |= txb_mask;
  		}
  
  		ath6kl_dbg(ATH6KL_DBG_HTC, "htc tx pkts to scatter: %d
  ",
  			   n_scat);
  
  		scat_req->len = 0;
  		scat_req->scat_entries = 0;
  
  		status = ath6kl_htc_tx_setup_scat_list(target, endpoint,
  						       scat_req, n_scat,
  						       queue);
  		if (status == -EAGAIN) {
  			hif_scatter_req_add(target->dev->ar, scat_req);
  			break;
  		}
  
  		/* send path is always asynchronous */
  		scat_req->complete = htc_async_tx_scat_complete;
  		n_sent_bundle++;
  		tot_pkts_bundle += scat_req->scat_entries;
  
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc tx scatter bytes %d entries %d
  ",
  			   scat_req->len, scat_req->scat_entries);
  
  		for (i = 0; i < scat_req->scat_entries; i++) {
  			packet = scat_req->scat_list[i].packet;
  			trace_ath6kl_htc_tx(packet->status, packet->endpoint,
  					    packet->buf, packet->act_len);
  		}
  
  		ath6kl_hif_submit_scat_req(target->dev, scat_req, false);
  
  		if (status)
  			break;
  	}
  
  	*sent_bundle = n_sent_bundle;
  	*n_bundle_pkts = tot_pkts_bundle;
  	ath6kl_dbg(ATH6KL_DBG_HTC, "htc tx bundle sent %d pkts
  ",
  		   n_sent_bundle);
  
  	return;
  }
  
  static void ath6kl_htc_tx_from_queue(struct htc_target *target,
  				     struct htc_endpoint *endpoint)
  {
  	struct list_head txq;
  	struct htc_packet *packet;
  	int bundle_sent;
  	int n_pkts_bundle;
  	u8 ac = WMM_NUM_AC;
  	int status;
  
  	spin_lock_bh(&target->tx_lock);
  
  	endpoint->tx_proc_cnt++;
  	if (endpoint->tx_proc_cnt > 1) {
  		endpoint->tx_proc_cnt--;
  		spin_unlock_bh(&target->tx_lock);
  		ath6kl_dbg(ATH6KL_DBG_HTC, "htc tx busy
  ");
  		return;
  	}
  
  	/*
  	 * drain the endpoint TX queue for transmission as long
  	 * as we have enough credits.
  	 */
  	INIT_LIST_HEAD(&txq);
  
  	if ((HTC_CTRL_RSVD_SVC != endpoint->svc_id) &&
  	    (WMI_CONTROL_SVC != endpoint->svc_id))
  		ac = target->dev->ar->ep2ac_map[endpoint->eid];
  
  	while (true) {
  		if (list_empty(&endpoint->txq))
  			break;
  
  		ath6kl_htc_tx_pkts_get(target, endpoint, &txq);
  
  		if (list_empty(&txq))
  			break;
  
  		spin_unlock_bh(&target->tx_lock);
  
  		bundle_sent = 0;
  		n_pkts_bundle = 0;
  
  		while (true) {
  			/* try to send a bundle on each pass */
  			if ((target->tx_bndl_mask) &&
  			    (get_queue_depth(&txq) >=
  			    HTC_MIN_HTC_MSGS_TO_BUNDLE)) {
  				int temp1 = 0, temp2 = 0;
  
  				/* check if bundling is enabled for an AC */
  				if (target->tx_bndl_mask & (1 << ac)) {
  					ath6kl_htc_tx_bundle(endpoint, &txq,
  							     &temp1, &temp2);
  					bundle_sent += temp1;
  					n_pkts_bundle += temp2;
  				}
  			}
  
  			if (list_empty(&txq))
  				break;
  
  			packet = list_first_entry(&txq, struct htc_packet,
  						  list);
  			list_del(&packet->list);
  
  			ath6kl_htc_tx_prep_pkt(packet, packet->info.tx.flags,
  					       0, packet->info.tx.seqno);
  			status = ath6kl_htc_tx_issue(target, packet);
  
  			if (status) {
  				packet->status = status;
  				packet->completion(packet->context, packet);
  			}
  		}
  
  		spin_lock_bh(&target->tx_lock);
  
  		endpoint->ep_st.tx_bundles += bundle_sent;
  		endpoint->ep_st.tx_pkt_bundled += n_pkts_bundle;
  
  		/*
  		 * if an AC has bundling disabled and no tx bundling
  		 * has occured continously for a certain number of TX,
  		 * enable tx bundling for this AC
  		 */
  		if (!bundle_sent) {
  			if (!(target->tx_bndl_mask & (1 << ac)) &&
  			    (ac < WMM_NUM_AC)) {
  				if (++target->ac_tx_count[ac] >=
  					TX_RESUME_BUNDLE_THRESHOLD) {
  					target->ac_tx_count[ac] = 0;
  					target->tx_bndl_mask |= (1 << ac);
  				}
  			}
  		} else {
  			/* tx bundling will reset the counter */
  			if (ac < WMM_NUM_AC)
  				target->ac_tx_count[ac] = 0;
  		}
  	}
  
  	endpoint->tx_proc_cnt = 0;
  	spin_unlock_bh(&target->tx_lock);
  }
  
  static bool ath6kl_htc_tx_try(struct htc_target *target,
  			      struct htc_endpoint *endpoint,
  			      struct htc_packet *tx_pkt)
  {
  	struct htc_ep_callbacks ep_cb;
  	int txq_depth;
  	bool overflow = false;
  
  	ep_cb = endpoint->ep_cb;
  
  	spin_lock_bh(&target->tx_lock);
  	txq_depth = get_queue_depth(&endpoint->txq);
  	spin_unlock_bh(&target->tx_lock);
  
  	if (txq_depth >= endpoint->max_txq_depth)
  		overflow = true;
  
  	if (overflow)
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc tx overflow ep %d depth %d max %d
  ",
  			   endpoint->eid, txq_depth,
  			   endpoint->max_txq_depth);
  
  	if (overflow && ep_cb.tx_full) {
  		if (ep_cb.tx_full(endpoint->target, tx_pkt) ==
  		    HTC_SEND_FULL_DROP) {
  			endpoint->ep_st.tx_dropped += 1;
  			return false;
  		}
  	}
  
  	spin_lock_bh(&target->tx_lock);
  	list_add_tail(&tx_pkt->list, &endpoint->txq);
  	spin_unlock_bh(&target->tx_lock);
  
  	ath6kl_htc_tx_from_queue(target, endpoint);
  
  	return true;
  }
  
  static void htc_chk_ep_txq(struct htc_target *target)
  {
  	struct htc_endpoint *endpoint;
  	struct htc_endpoint_credit_dist *cred_dist;
  
  	/*
  	 * Run through the credit distribution list to see if there are
  	 * packets queued. NOTE: no locks need to be taken since the
  	 * distribution list is not dynamic (cannot be re-ordered) and we
  	 * are not modifying any state.
  	 */
  	list_for_each_entry(cred_dist, &target->cred_dist_list, list) {
  		endpoint = cred_dist->htc_ep;
  
  		spin_lock_bh(&target->tx_lock);
  		if (!list_empty(&endpoint->txq)) {
  			ath6kl_dbg(ATH6KL_DBG_HTC,
  				   "htc creds ep %d credits %d pkts %d
  ",
  				   cred_dist->endpoint,
  				   endpoint->cred_dist.credits,
  				   get_queue_depth(&endpoint->txq));
  			spin_unlock_bh(&target->tx_lock);
  			/*
  			 * Try to start the stalled queue, this list is
  			 * ordered by priority. If there are credits
  			 * available the highest priority queue will get a
  			 * chance to reclaim credits from lower priority
  			 * ones.
  			 */
  			ath6kl_htc_tx_from_queue(target, endpoint);
  			spin_lock_bh(&target->tx_lock);
  		}
  		spin_unlock_bh(&target->tx_lock);
  	}
  }
  
  static int htc_setup_tx_complete(struct htc_target *target)
  {
  	struct htc_packet *send_pkt = NULL;
  	int status;
  
  	send_pkt = htc_get_control_buf(target, true);
  
  	if (!send_pkt)
  		return -ENOMEM;
  
  	if (target->htc_tgt_ver >= HTC_VERSION_2P1) {
  		struct htc_setup_comp_ext_msg *setup_comp_ext;
  		u32 flags = 0;
  
  		setup_comp_ext =
  		    (struct htc_setup_comp_ext_msg *)send_pkt->buf;
  		memset(setup_comp_ext, 0, sizeof(*setup_comp_ext));
  		setup_comp_ext->msg_id =
  			cpu_to_le16(HTC_MSG_SETUP_COMPLETE_EX_ID);
  
  		if (target->msg_per_bndl_max > 0) {
  			/* Indicate HTC bundling to the target */
  			flags |= HTC_SETUP_COMP_FLG_RX_BNDL_EN;
  			setup_comp_ext->msg_per_rxbndl =
  						target->msg_per_bndl_max;
  		}
  
  		memcpy(&setup_comp_ext->flags, &flags,
  		       sizeof(setup_comp_ext->flags));
  		set_htc_pkt_info(send_pkt, NULL, (u8 *) setup_comp_ext,
  				 sizeof(struct htc_setup_comp_ext_msg),
  				 ENDPOINT_0, HTC_SERVICE_TX_PACKET_TAG);
  
  	} else {
  		struct htc_setup_comp_msg *setup_comp;
  		setup_comp = (struct htc_setup_comp_msg *)send_pkt->buf;
  		memset(setup_comp, 0, sizeof(struct htc_setup_comp_msg));
  		setup_comp->msg_id = cpu_to_le16(HTC_MSG_SETUP_COMPLETE_ID);
  		set_htc_pkt_info(send_pkt, NULL, (u8 *) setup_comp,
  				 sizeof(struct htc_setup_comp_msg),
  				 ENDPOINT_0, HTC_SERVICE_TX_PACKET_TAG);
  	}
  
  	/* we want synchronous operation */
  	send_pkt->completion = NULL;
  	ath6kl_htc_tx_prep_pkt(send_pkt, 0, 0, 0);
  	status = ath6kl_htc_tx_issue(target, send_pkt);
  	htc_reclaim_txctrl_buf(target, send_pkt);
  
  	return status;
  }
  
  static void ath6kl_htc_set_credit_dist(struct htc_target *target,
  				struct ath6kl_htc_credit_info *credit_info,
  				u16 srvc_pri_order[], int list_len)
  {
  	struct htc_endpoint *endpoint;
  	int i, ep;
  
  	target->credit_info = credit_info;
  
  	list_add_tail(&target->endpoint[ENDPOINT_0].cred_dist.list,
  		      &target->cred_dist_list);
  
  	for (i = 0; i < list_len; i++) {
  		for (ep = ENDPOINT_1; ep < ENDPOINT_MAX; ep++) {
  			endpoint = &target->endpoint[ep];
  			if (endpoint->svc_id == srvc_pri_order[i]) {
  				list_add_tail(&endpoint->cred_dist.list,
  					      &target->cred_dist_list);
  				break;
  			}
  		}
  		if (ep >= ENDPOINT_MAX) {
  			WARN_ON(1);
  			return;
  		}
  	}
  }
  
  static int ath6kl_htc_mbox_tx(struct htc_target *target,
  			      struct htc_packet *packet)
  {
  	struct htc_endpoint *endpoint;
  	struct list_head queue;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc tx ep id %d buf 0x%p len %d
  ",
  		   packet->endpoint, packet->buf, packet->act_len);
  
  	if (packet->endpoint >= ENDPOINT_MAX) {
  		WARN_ON(1);
  		return -EINVAL;
  	}
  
  	endpoint = &target->endpoint[packet->endpoint];
  
  	if (!ath6kl_htc_tx_try(target, endpoint, packet)) {
  		packet->status = (target->htc_flags & HTC_OP_STATE_STOPPING) ?
  				 -ECANCELED : -ENOSPC;
  		INIT_LIST_HEAD(&queue);
  		list_add(&packet->list, &queue);
  		htc_tx_complete(endpoint, &queue);
  	}
  
  	return 0;
  }
  
  /* flush endpoint TX queue */
  static void ath6kl_htc_mbox_flush_txep(struct htc_target *target,
  			   enum htc_endpoint_id eid, u16 tag)
  {
  	struct htc_packet *packet, *tmp_pkt;
  	struct list_head discard_q, container;
  	struct htc_endpoint *endpoint = &target->endpoint[eid];
  
  	if (!endpoint->svc_id) {
  		WARN_ON(1);
  		return;
  	}
  
  	/* initialize the discard queue */
  	INIT_LIST_HEAD(&discard_q);
  
  	spin_lock_bh(&target->tx_lock);
  
  	list_for_each_entry_safe(packet, tmp_pkt, &endpoint->txq, list) {
  		if ((tag == HTC_TX_PACKET_TAG_ALL) ||
  		    (tag == packet->info.tx.tag))
  			list_move_tail(&packet->list, &discard_q);
  	}
  
  	spin_unlock_bh(&target->tx_lock);
  
  	list_for_each_entry_safe(packet, tmp_pkt, &discard_q, list) {
  		packet->status = -ECANCELED;
  		list_del(&packet->list);
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc tx flushing pkt 0x%p len %d  ep %d tag 0x%x
  ",
  			   packet, packet->act_len,
  			   packet->endpoint, packet->info.tx.tag);
  
  		INIT_LIST_HEAD(&container);
  		list_add_tail(&packet->list, &container);
  		htc_tx_complete(endpoint, &container);
  	}
  }
  
  static void ath6kl_htc_flush_txep_all(struct htc_target *target)
  {
  	struct htc_endpoint *endpoint;
  	int i;
  
  	dump_cred_dist_stats(target);
  
  	for (i = ENDPOINT_0; i < ENDPOINT_MAX; i++) {
  		endpoint = &target->endpoint[i];
  		if (endpoint->svc_id == 0)
  			/* not in use.. */
  			continue;
  		ath6kl_htc_mbox_flush_txep(target, i, HTC_TX_PACKET_TAG_ALL);
  	}
  }
  
  static void ath6kl_htc_mbox_activity_changed(struct htc_target *target,
  					     enum htc_endpoint_id eid,
  					     bool active)
  {
  	struct htc_endpoint *endpoint = &target->endpoint[eid];
  	bool dist = false;
  
  	if (endpoint->svc_id == 0) {
  		WARN_ON(1);
  		return;
  	}
  
  	spin_lock_bh(&target->tx_lock);
  
  	if (active) {
  		if (!(endpoint->cred_dist.dist_flags & HTC_EP_ACTIVE)) {
  			endpoint->cred_dist.dist_flags |= HTC_EP_ACTIVE;
  			dist = true;
  		}
  	} else {
  		if (endpoint->cred_dist.dist_flags & HTC_EP_ACTIVE) {
  			endpoint->cred_dist.dist_flags &= ~HTC_EP_ACTIVE;
  			dist = true;
  		}
  	}
  
  	if (dist) {
  		endpoint->cred_dist.txq_depth =
  			get_queue_depth(&endpoint->txq);
  
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc tx activity ctxt 0x%p dist 0x%p
  ",
  			   target->credit_info, &target->cred_dist_list);
  
  		ath6kl_credit_distribute(target->credit_info,
  					 &target->cred_dist_list,
  					 HTC_CREDIT_DIST_ACTIVITY_CHANGE);
  	}
  
  	spin_unlock_bh(&target->tx_lock);
  
  	if (dist && !active)
  		htc_chk_ep_txq(target);
  }
  
  /* HTC Rx */
  
  static inline void ath6kl_htc_rx_update_stats(struct htc_endpoint *endpoint,
  					      int n_look_ahds)
  {
  	endpoint->ep_st.rx_pkts++;
  	if (n_look_ahds == 1)
  		endpoint->ep_st.rx_lkahds++;
  	else if (n_look_ahds > 1)
  		endpoint->ep_st.rx_bundle_lkahd++;
  }
  
  static inline bool htc_valid_rx_frame_len(struct htc_target *target,
  					  enum htc_endpoint_id eid, int len)
  {
  	return (eid == target->dev->ar->ctrl_ep) ?
  		len <= ATH6KL_BUFFER_SIZE : len <= ATH6KL_AMSDU_BUFFER_SIZE;
  }
  
  static int htc_add_rxbuf(struct htc_target *target, struct htc_packet *packet)
  {
  	struct list_head queue;
  
  	INIT_LIST_HEAD(&queue);
  	list_add_tail(&packet->list, &queue);
  	return ath6kl_htc_mbox_add_rxbuf_multiple(target, &queue);
  }
  
  static void htc_reclaim_rxbuf(struct htc_target *target,
  			      struct htc_packet *packet,
  			      struct htc_endpoint *ep)
  {
  	if (packet->info.rx.rx_flags & HTC_RX_PKT_NO_RECYCLE) {
  		htc_rxpkt_reset(packet);
  		packet->status = -ECANCELED;
  		ep->ep_cb.rx(ep->target, packet);
  	} else {
  		htc_rxpkt_reset(packet);
  		htc_add_rxbuf((void *)(target), packet);
  	}
  }
  
  static void reclaim_rx_ctrl_buf(struct htc_target *target,
  				struct htc_packet *packet)
  {
  	spin_lock_bh(&target->htc_lock);
  	list_add_tail(&packet->list, &target->free_ctrl_rxbuf);
  	spin_unlock_bh(&target->htc_lock);
  }
  
  static int ath6kl_htc_rx_packet(struct htc_target *target,
  				struct htc_packet *packet,
  				u32 rx_len)
  {
  	struct ath6kl_device *dev = target->dev;
  	u32 padded_len;
  	int status;
  
  	padded_len = CALC_TXRX_PADDED_LEN(target, rx_len);
  
  	if (padded_len > packet->buf_len) {
  		ath6kl_err("not enough receive space for packet - padlen %d recvlen %d bufferlen %d
  ",
  			   padded_len, rx_len, packet->buf_len);
  		return -ENOMEM;
  	}
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc rx 0x%p hdr 0x%x len %d mbox 0x%x
  ",
  		   packet, packet->info.rx.exp_hdr,
  		   padded_len, dev->ar->mbox_info.htc_addr);
  
  	status = hif_read_write_sync(dev->ar,
  				     dev->ar->mbox_info.htc_addr,
  				     packet->buf, padded_len,
  				     HIF_RD_SYNC_BLOCK_FIX);
  
  	packet->status = status;
  
  	return status;
  }
  
  /*
   * optimization for recv packets, we can indicate a
   * "hint" that there are more  single-packets to fetch
   * on this endpoint.
   */
  static void ath6kl_htc_rx_set_indicate(u32 lk_ahd,
  				       struct htc_endpoint *endpoint,
  				       struct htc_packet *packet)
  {
  	struct htc_frame_hdr *htc_hdr = (struct htc_frame_hdr *)&lk_ahd;
  
  	if (htc_hdr->eid == packet->endpoint) {
  		if (!list_empty(&endpoint->rx_bufq))
  			packet->info.rx.indicat_flags |=
  					HTC_RX_FLAGS_INDICATE_MORE_PKTS;
  	}
  }
  
  static void ath6kl_htc_rx_chk_water_mark(struct htc_endpoint *endpoint)
  {
  	struct htc_ep_callbacks ep_cb = endpoint->ep_cb;
  
  	if (ep_cb.rx_refill_thresh > 0) {
  		spin_lock_bh(&endpoint->target->rx_lock);
  		if (get_queue_depth(&endpoint->rx_bufq)
  		    < ep_cb.rx_refill_thresh) {
  			spin_unlock_bh(&endpoint->target->rx_lock);
  			ep_cb.rx_refill(endpoint->target, endpoint->eid);
  			return;
  		}
  		spin_unlock_bh(&endpoint->target->rx_lock);
  	}
  }
  
  /* This function is called with rx_lock held */
  static int ath6kl_htc_rx_setup(struct htc_target *target,
  			       struct htc_endpoint *ep,
  			       u32 *lk_ahds, struct list_head *queue, int n_msg)
  {
  	struct htc_packet *packet;
  	/* FIXME: type of lk_ahds can't be right */
  	struct htc_frame_hdr *htc_hdr = (struct htc_frame_hdr *)lk_ahds;
  	struct htc_ep_callbacks ep_cb;
  	int status = 0, j, full_len;
  	bool no_recycle;
  
  	full_len = CALC_TXRX_PADDED_LEN(target,
  					le16_to_cpu(htc_hdr->payld_len) +
  					sizeof(*htc_hdr));
  
  	if (!htc_valid_rx_frame_len(target, ep->eid, full_len)) {
  		ath6kl_warn("Rx buffer requested with invalid length htc_hdr:eid %d, flags 0x%x, len %d
  ",
  			    htc_hdr->eid, htc_hdr->flags,
  			    le16_to_cpu(htc_hdr->payld_len));
  		return -EINVAL;
  	}
  
  	ep_cb = ep->ep_cb;
  	for (j = 0; j < n_msg; j++) {
  		/*
  		 * Reset flag, any packets allocated using the
  		 * rx_alloc() API cannot be recycled on
  		 * cleanup,they must be explicitly returned.
  		 */
  		no_recycle = false;
  
  		if (ep_cb.rx_allocthresh &&
  		    (full_len > ep_cb.rx_alloc_thresh)) {
  			ep->ep_st.rx_alloc_thresh_hit += 1;
  			ep->ep_st.rxalloc_thresh_byte +=
  				le16_to_cpu(htc_hdr->payld_len);
  
  			spin_unlock_bh(&target->rx_lock);
  			no_recycle = true;
  
  			packet = ep_cb.rx_allocthresh(ep->target, ep->eid,
  						      full_len);
  			spin_lock_bh(&target->rx_lock);
  		} else {
  			/* refill handler is being used */
  			if (list_empty(&ep->rx_bufq)) {
  				if (ep_cb.rx_refill) {
  					spin_unlock_bh(&target->rx_lock);
  					ep_cb.rx_refill(ep->target, ep->eid);
  					spin_lock_bh(&target->rx_lock);
  				}
  			}
  
  			if (list_empty(&ep->rx_bufq)) {
  				packet = NULL;
  			} else {
  				packet = list_first_entry(&ep->rx_bufq,
  						struct htc_packet, list);
  				list_del(&packet->list);
  			}
  		}
  
  		if (!packet) {
  			target->rx_st_flags |= HTC_RECV_WAIT_BUFFERS;
  			target->ep_waiting = ep->eid;
  			return -ENOSPC;
  		}
  
  		/* clear flags */
  		packet->info.rx.rx_flags = 0;
  		packet->info.rx.indicat_flags = 0;
  		packet->status = 0;
  
  		if (no_recycle)
  			/*
  			 * flag that these packets cannot be
  			 * recycled, they have to be returned to
  			 * the user
  			 */
  			packet->info.rx.rx_flags |= HTC_RX_PKT_NO_RECYCLE;
  
  		/* Caller needs to free this upon any failure */
  		list_add_tail(&packet->list, queue);
  
  		if (target->htc_flags & HTC_OP_STATE_STOPPING) {
  			status = -ECANCELED;
  			break;
  		}
  
  		if (j) {
  			packet->info.rx.rx_flags |= HTC_RX_PKT_REFRESH_HDR;
  			packet->info.rx.exp_hdr = 0xFFFFFFFF;
  		} else
  			/* set expected look ahead */
  			packet->info.rx.exp_hdr = *lk_ahds;
  
  		packet->act_len = le16_to_cpu(htc_hdr->payld_len) +
  			HTC_HDR_LENGTH;
  	}
  
  	return status;
  }
  
  static int ath6kl_htc_rx_alloc(struct htc_target *target,
  			       u32 lk_ahds[], int msg,
  			       struct htc_endpoint *endpoint,
  			       struct list_head *queue)
  {
  	int status = 0;
  	struct htc_packet *packet, *tmp_pkt;
  	struct htc_frame_hdr *htc_hdr;
  	int i, n_msg;
  
  	spin_lock_bh(&target->rx_lock);
  
  	for (i = 0; i < msg; i++) {
  		htc_hdr = (struct htc_frame_hdr *)&lk_ahds[i];
  
  		if (htc_hdr->eid >= ENDPOINT_MAX) {
  			ath6kl_err("invalid ep in look-ahead: %d
  ",
  				   htc_hdr->eid);
  			status = -ENOMEM;
  			break;
  		}
  
  		if (htc_hdr->eid != endpoint->eid) {
  			ath6kl_err("invalid ep in look-ahead: %d should be : %d (index:%d)
  ",
  				   htc_hdr->eid, endpoint->eid, i);
  			status = -ENOMEM;
  			break;
  		}
  
  		if (le16_to_cpu(htc_hdr->payld_len) > HTC_MAX_PAYLOAD_LENGTH) {
  			ath6kl_err("payload len %d exceeds max htc : %d !
  ",
  				   htc_hdr->payld_len,
  				   (u32) HTC_MAX_PAYLOAD_LENGTH);
  			status = -ENOMEM;
  			break;
  		}
  
  		if (endpoint->svc_id == 0) {
  			ath6kl_err("ep %d is not connected !
  ", htc_hdr->eid);
  			status = -ENOMEM;
  			break;
  		}
  
  		if (htc_hdr->flags & HTC_FLG_RX_BNDL_CNT) {
  			/*
  			 * HTC header indicates that every packet to follow
  			 * has the same padded length so that it can be
  			 * optimally fetched as a full bundle.
  			 */
  			n_msg = (htc_hdr->flags & HTC_FLG_RX_BNDL_CNT) >>
  				HTC_FLG_RX_BNDL_CNT_S;
  
  			/* the count doesn't include the starter frame */
  			n_msg++;
  			if (n_msg > target->msg_per_bndl_max) {
  				status = -ENOMEM;
  				break;
  			}
  
  			endpoint->ep_st.rx_bundle_from_hdr += 1;
  			ath6kl_dbg(ATH6KL_DBG_HTC,
  				   "htc rx bundle pkts %d
  ",
  				   n_msg);
  		} else
  			/* HTC header only indicates 1 message to fetch */
  			n_msg = 1;
  
  		/* Setup packet buffers for each message */
  		status = ath6kl_htc_rx_setup(target, endpoint, &lk_ahds[i],
  					     queue, n_msg);
  
  		/*
  		 * This is due to unavailabilty of buffers to rx entire data.
  		 * Return no error so that free buffers from queue can be used
  		 * to receive partial data.
  		 */
  		if (status == -ENOSPC) {
  			spin_unlock_bh(&target->rx_lock);
  			return 0;
  		}
  
  		if (status)
  			break;
  	}
  
  	spin_unlock_bh(&target->rx_lock);
  
  	if (status) {
  		list_for_each_entry_safe(packet, tmp_pkt, queue, list) {
  			list_del(&packet->list);
  			htc_reclaim_rxbuf(target, packet,
  					  &target->endpoint[packet->endpoint]);
  		}
  	}
  
  	return status;
  }
  
  static void htc_ctrl_rx(struct htc_target *context, struct htc_packet *packets)
  {
  	if (packets->endpoint != ENDPOINT_0) {
  		WARN_ON(1);
  		return;
  	}
  
  	if (packets->status == -ECANCELED) {
  		reclaim_rx_ctrl_buf(context, packets);
  		return;
  	}
  
  	if (packets->act_len > 0) {
  		ath6kl_err("htc_ctrl_rx, got message with len:%zu
  ",
  			   packets->act_len + HTC_HDR_LENGTH);
  
  		ath6kl_dbg_dump(ATH6KL_DBG_HTC,
  				"htc rx unexpected endpoint 0 message", "",
  				packets->buf - HTC_HDR_LENGTH,
  				packets->act_len + HTC_HDR_LENGTH);
  	}
  
  	htc_reclaim_rxbuf(context, packets, &context->endpoint[0]);
  }
  
  static void htc_proc_cred_rpt(struct htc_target *target,
  			      struct htc_credit_report *rpt,
  			      int n_entries,
  			      enum htc_endpoint_id from_ep)
  {
  	struct htc_endpoint *endpoint;
  	int tot_credits = 0, i;
  	bool dist = false;
  
  	spin_lock_bh(&target->tx_lock);
  
  	for (i = 0; i < n_entries; i++, rpt++) {
  		if (rpt->eid >= ENDPOINT_MAX) {
  			WARN_ON(1);
  			spin_unlock_bh(&target->tx_lock);
  			return;
  		}
  
  		endpoint = &target->endpoint[rpt->eid];
  
  		ath6kl_dbg(ATH6KL_DBG_CREDIT,
  			   "credit report ep %d credits %d
  ",
  			   rpt->eid, rpt->credits);
  
  		endpoint->ep_st.tx_cred_rpt += 1;
  		endpoint->ep_st.cred_retnd += rpt->credits;
  
  		if (from_ep == rpt->eid) {
  			/*
  			 * This credit report arrived on the same endpoint
  			 * indicating it arrived in an RX packet.
  			 */
  			endpoint->ep_st.cred_from_rx += rpt->credits;
  			endpoint->ep_st.cred_rpt_from_rx += 1;
  		} else if (from_ep == ENDPOINT_0) {
  			/* credit arrived on endpoint 0 as a NULL message */
  			endpoint->ep_st.cred_from_ep0 += rpt->credits;
  			endpoint->ep_st.cred_rpt_ep0 += 1;
  		} else {
  			endpoint->ep_st.cred_from_other += rpt->credits;
  			endpoint->ep_st.cred_rpt_from_other += 1;
  		}
  
  		if (rpt->eid == ENDPOINT_0)
  			/* always give endpoint 0 credits back */
  			endpoint->cred_dist.credits += rpt->credits;
  		else {
  			endpoint->cred_dist.cred_to_dist += rpt->credits;
  			dist = true;
  		}
  
  		/*
  		 * Refresh tx depth for distribution function that will
  		 * recover these credits NOTE: this is only valid when
  		 * there are credits to recover!
  		 */
  		endpoint->cred_dist.txq_depth =
  			get_queue_depth(&endpoint->txq);
  
  		tot_credits += rpt->credits;
  	}
  
  	if (dist) {
  		/*
  		 * This was a credit return based on a completed send
  		 * operations note, this is done with the lock held
  		 */
  		ath6kl_credit_distribute(target->credit_info,
  					 &target->cred_dist_list,
  					 HTC_CREDIT_DIST_SEND_COMPLETE);
  	}
  
  	spin_unlock_bh(&target->tx_lock);
  
  	if (tot_credits)
  		htc_chk_ep_txq(target);
  }
  
  static int htc_parse_trailer(struct htc_target *target,
  			     struct htc_record_hdr *record,
  			     u8 *record_buf, u32 *next_lk_ahds,
  			     enum htc_endpoint_id endpoint,
  			     int *n_lk_ahds)
  {
  	struct htc_bundle_lkahd_rpt *bundle_lkahd_rpt;
  	struct htc_lookahead_report *lk_ahd;
  	int len;
  
  	switch (record->rec_id) {
  	case HTC_RECORD_CREDITS:
  		len = record->len / sizeof(struct htc_credit_report);
  		if (!len) {
  			WARN_ON(1);
  			return -EINVAL;
  		}
  
  		htc_proc_cred_rpt(target,
  				  (struct htc_credit_report *) record_buf,
  				  len, endpoint);
  		break;
  	case HTC_RECORD_LOOKAHEAD:
  		len = record->len / sizeof(*lk_ahd);
  		if (!len) {
  			WARN_ON(1);
  			return -EINVAL;
  		}
  
  		lk_ahd = (struct htc_lookahead_report *) record_buf;
  		if ((lk_ahd->pre_valid == ((~lk_ahd->post_valid) & 0xFF)) &&
  		    next_lk_ahds) {
  			ath6kl_dbg(ATH6KL_DBG_HTC,
  				   "htc rx lk_ahd found pre_valid 0x%x post_valid 0x%x
  ",
  				   lk_ahd->pre_valid, lk_ahd->post_valid);
  
  			/* look ahead bytes are valid, copy them over */
  			memcpy((u8 *)&next_lk_ahds[0], lk_ahd->lk_ahd, 4);
  
  			ath6kl_dbg_dump(ATH6KL_DBG_HTC,
  					"htc rx next look ahead",
  					"", next_lk_ahds, 4);
  
  			*n_lk_ahds = 1;
  		}
  		break;
  	case HTC_RECORD_LOOKAHEAD_BUNDLE:
  		len = record->len / sizeof(*bundle_lkahd_rpt);
  		if (!len || (len > HTC_HOST_MAX_MSG_PER_BUNDLE)) {
  			WARN_ON(1);
  			return -EINVAL;
  		}
  
  		if (next_lk_ahds) {
  			int i;
  
  			bundle_lkahd_rpt =
  				(struct htc_bundle_lkahd_rpt *) record_buf;
  
  			ath6kl_dbg_dump(ATH6KL_DBG_HTC, "htc rx bundle lk_ahd",
  					"", record_buf, record->len);
  
  			for (i = 0; i < len; i++) {
  				memcpy((u8 *)&next_lk_ahds[i],
  				       bundle_lkahd_rpt->lk_ahd, 4);
  				bundle_lkahd_rpt++;
  			}
  
  			*n_lk_ahds = i;
  		}
  		break;
  	default:
  		ath6kl_err("unhandled record: id:%d len:%d
  ",
  			   record->rec_id, record->len);
  		break;
  	}
  
  	return 0;
  }
  
  static int htc_proc_trailer(struct htc_target *target,
  			    u8 *buf, int len, u32 *next_lk_ahds,
  			    int *n_lk_ahds, enum htc_endpoint_id endpoint)
  {
  	struct htc_record_hdr *record;
  	int orig_len;
  	int status;
  	u8 *record_buf;
  	u8 *orig_buf;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC, "htc rx trailer len %d
  ", len);
  	ath6kl_dbg_dump(ATH6KL_DBG_HTC, NULL, "", buf, len);
  
  	orig_buf = buf;
  	orig_len = len;
  	status = 0;
  
  	while (len > 0) {
  		if (len < sizeof(struct htc_record_hdr)) {
  			status = -ENOMEM;
  			break;
  		}
  		/* these are byte aligned structs */
  		record = (struct htc_record_hdr *) buf;
  		len -= sizeof(struct htc_record_hdr);
  		buf += sizeof(struct htc_record_hdr);
  
  		if (record->len > len) {
  			ath6kl_err("invalid record len: %d (id:%d) buf has: %d bytes left
  ",
  				   record->len, record->rec_id, len);
  			status = -ENOMEM;
  			break;
  		}
  		record_buf = buf;
  
  		status = htc_parse_trailer(target, record, record_buf,
  					   next_lk_ahds, endpoint, n_lk_ahds);
  
  		if (status)
  			break;
  
  		/* advance buffer past this record for next time around */
  		buf += record->len;
  		len -= record->len;
  	}
  
  	if (status)
  		ath6kl_dbg_dump(ATH6KL_DBG_HTC, "htc rx bad trailer",
  				"", orig_buf, orig_len);
  
  	return status;
  }
  
  static int ath6kl_htc_rx_process_hdr(struct htc_target *target,
  				     struct htc_packet *packet,
  				     u32 *next_lkahds, int *n_lkahds)
  {
  	int status = 0;
  	u16 payload_len;
  	u32 lk_ahd;
  	struct htc_frame_hdr *htc_hdr = (struct htc_frame_hdr *)packet->buf;
  
  	if (n_lkahds != NULL)
  		*n_lkahds = 0;
  
  	/*
  	 * NOTE: we cannot assume the alignment of buf, so we use the safe
  	 * macros to retrieve 16 bit fields.
  	 */
  	payload_len = le16_to_cpu(get_unaligned(&htc_hdr->payld_len));
  
  	memcpy((u8 *)&lk_ahd, packet->buf, sizeof(lk_ahd));
  
  	if (packet->info.rx.rx_flags & HTC_RX_PKT_REFRESH_HDR) {
  		/*
  		 * Refresh the expected header and the actual length as it
  		 * was unknown when this packet was grabbed as part of the
  		 * bundle.
  		 */
  		packet->info.rx.exp_hdr = lk_ahd;
  		packet->act_len = payload_len + HTC_HDR_LENGTH;
  
  		/* validate the actual header that was refreshed  */
  		if (packet->act_len > packet->buf_len) {
  			ath6kl_err("refreshed hdr payload len (%d) in bundled recv is invalid (hdr: 0x%X)
  ",
  				   payload_len, lk_ahd);
  			/*
  			 * Limit this to max buffer just to print out some
  			 * of the buffer.
  			 */
  			packet->act_len = min(packet->act_len, packet->buf_len);
  			status = -ENOMEM;
  			goto fail_rx;
  		}
  
  		if (packet->endpoint != htc_hdr->eid) {
  			ath6kl_err("refreshed hdr ep (%d) does not match expected ep (%d)
  ",
  				   htc_hdr->eid, packet->endpoint);
  			status = -ENOMEM;
  			goto fail_rx;
  		}
  	}
  
  	if (lk_ahd != packet->info.rx.exp_hdr) {
  		ath6kl_err("%s(): lk_ahd mismatch! (pPkt:0x%p flags:0x%X)
  ",
  			   __func__, packet, packet->info.rx.rx_flags);
  		ath6kl_dbg_dump(ATH6KL_DBG_HTC, "htc rx expected lk_ahd",
  				"", &packet->info.rx.exp_hdr, 4);
  		ath6kl_dbg_dump(ATH6KL_DBG_HTC, "htc rx current header",
  				"", (u8 *)&lk_ahd, sizeof(lk_ahd));
  		status = -ENOMEM;
  		goto fail_rx;
  	}
  
  	if (htc_hdr->flags & HTC_FLG_RX_TRAILER) {
  		if (htc_hdr->ctrl[0] < sizeof(struct htc_record_hdr) ||
  		    htc_hdr->ctrl[0] > payload_len) {
  			ath6kl_err("%s(): invalid hdr (payload len should be :%d, CB[0] is:%d)
  ",
  				   __func__, payload_len, htc_hdr->ctrl[0]);
  			status = -ENOMEM;
  			goto fail_rx;
  		}
  
  		if (packet->info.rx.rx_flags & HTC_RX_PKT_IGNORE_LOOKAHEAD) {
  			next_lkahds = NULL;
  			n_lkahds = NULL;
  		}
  
  		status = htc_proc_trailer(target, packet->buf + HTC_HDR_LENGTH
  					  + payload_len - htc_hdr->ctrl[0],
  					  htc_hdr->ctrl[0], next_lkahds,
  					   n_lkahds, packet->endpoint);
  
  		if (status)
  			goto fail_rx;
  
  		packet->act_len -= htc_hdr->ctrl[0];
  	}
  
  	packet->buf += HTC_HDR_LENGTH;
  	packet->act_len -= HTC_HDR_LENGTH;
  
  fail_rx:
  	if (status)
  		ath6kl_dbg_dump(ATH6KL_DBG_HTC, "htc rx bad packet",
  				"", packet->buf, packet->act_len);
  
  	return status;
  }
  
  static void ath6kl_htc_rx_complete(struct htc_endpoint *endpoint,
  				   struct htc_packet *packet)
  {
  		ath6kl_dbg(ATH6KL_DBG_HTC,
  			   "htc rx complete ep %d packet 0x%p
  ",
  			   endpoint->eid, packet);
  
  		endpoint->ep_cb.rx(endpoint->target, packet);
  }
  
  static int ath6kl_htc_rx_bundle(struct htc_target *target,
  				struct list_head *rxq,
  				struct list_head *sync_compq,
  				int *n_pkt_fetched, bool part_bundle)
  {
  	struct hif_scatter_req *scat_req;
  	struct htc_packet *packet;
  	int rem_space = target->max_rx_bndl_sz;
  	int n_scat_pkt, status = 0, i, len;
  
  	n_scat_pkt = get_queue_depth(rxq);
  	n_scat_pkt = min(n_scat_pkt, target->msg_per_bndl_max);
  
  	if ((get_queue_depth(rxq) - n_scat_pkt) > 0) {
  		/*
  		 * We were forced to split this bundle receive operation
  		 * all packets in this partial bundle must have their
  		 * lookaheads ignored.
  		 */
  		part_bundle = true;
  
  		/*
  		 * This would only happen if the target ignored our max
  		 * bundle limit.
  		 */
  		ath6kl_warn("%s(): partial bundle detected num:%d , %d
  ",
  			    __func__, get_queue_depth(rxq), n_scat_pkt);
  	}
  
  	len = 0;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc rx bundle depth %d pkts %d
  ",
  		   get_queue_depth(rxq), n_scat_pkt);
  
  	scat_req = hif_scatter_req_get(target->dev->ar);
  
  	if (scat_req == NULL)
  		goto fail_rx_pkt;
  
  	for (i = 0; i < n_scat_pkt; i++) {
  		int pad_len;
  
  		packet = list_first_entry(rxq, struct htc_packet, list);
  		list_del(&packet->list);
  
  		pad_len = CALC_TXRX_PADDED_LEN(target,
  						   packet->act_len);
  
  		if ((rem_space - pad_len) < 0) {
  			list_add(&packet->list, rxq);
  			break;
  		}
  
  		rem_space -= pad_len;
  
  		if (part_bundle || (i < (n_scat_pkt - 1)))
  			/*
  			 * Packet 0..n-1 cannot be checked for look-aheads
  			 * since we are fetching a bundle the last packet
  			 * however can have it's lookahead used
  			 */
  			packet->info.rx.rx_flags |=
  			    HTC_RX_PKT_IGNORE_LOOKAHEAD;
  
  		/* NOTE: 1 HTC packet per scatter entry */
  		scat_req->scat_list[i].buf = packet->buf;
  		scat_req->scat_list[i].len = pad_len;
  
  		packet->info.rx.rx_flags |= HTC_RX_PKT_PART_OF_BUNDLE;
  
  		list_add_tail(&packet->list, sync_compq);
  
  		WARN_ON(!scat_req->scat_list[i].len);
  		len += scat_req->scat_list[i].len;
  	}
  
  	scat_req->len = len;
  	scat_req->scat_entries = i;
  
  	status = ath6kl_hif_submit_scat_req(target->dev, scat_req, true);
  
  	if (!status)
  		*n_pkt_fetched = i;
  
  	/* free scatter request */
  	hif_scatter_req_add(target->dev->ar, scat_req);
  
  fail_rx_pkt:
  
  	return status;
  }
  
  static int ath6kl_htc_rx_process_packets(struct htc_target *target,
  					 struct list_head *comp_pktq,
  					 u32 lk_ahds[],
  					 int *n_lk_ahd)
  {
  	struct htc_packet *packet, *tmp_pkt;
  	struct htc_endpoint *ep;
  	int status = 0;
  
  	list_for_each_entry_safe(packet, tmp_pkt, comp_pktq, list) {
  		ep = &target->endpoint[packet->endpoint];
  
  		trace_ath6kl_htc_rx(packet->status, packet->endpoint,
  				    packet->buf, packet->act_len);
  
  		/* process header for each of the recv packet */
  		status = ath6kl_htc_rx_process_hdr(target, packet, lk_ahds,
  						   n_lk_ahd);
  		if (status)
  			return status;
  
  		list_del(&packet->list);
  
  		if (list_empty(comp_pktq)) {
  			/*
  			 * Last packet's more packet flag is set
  			 * based on the lookahead.
  			 */
  			if (*n_lk_ahd > 0)
  				ath6kl_htc_rx_set_indicate(lk_ahds[0],
  							   ep, packet);
  		} else
  			/*
  			 * Packets in a bundle automatically have
  			 * this flag set.
  			 */
  			packet->info.rx.indicat_flags |=
  				HTC_RX_FLAGS_INDICATE_MORE_PKTS;
  
  		ath6kl_htc_rx_update_stats(ep, *n_lk_ahd);
  
  		if (packet->info.rx.rx_flags & HTC_RX_PKT_PART_OF_BUNDLE)
  			ep->ep_st.rx_bundl += 1;
  
  		ath6kl_htc_rx_complete(ep, packet);
  	}
  
  	return status;
  }
  
  static int ath6kl_htc_rx_fetch(struct htc_target *target,
  			       struct list_head *rx_pktq,
  			       struct list_head *comp_pktq)
  {
  	int fetched_pkts;
  	bool part_bundle = false;
  	int status = 0;
  	struct list_head tmp_rxq;
  	struct htc_packet *packet, *tmp_pkt;
  
  	/* now go fetch the list of HTC packets */
  	while (!list_empty(rx_pktq)) {
  		fetched_pkts = 0;
  
  		INIT_LIST_HEAD(&tmp_rxq);
  
  		if (target->rx_bndl_enable && (get_queue_depth(rx_pktq) > 1)) {
  			/*
  			 * There are enough packets to attempt a
  			 * bundle transfer and recv bundling is
  			 * allowed.
  			 */
  			status = ath6kl_htc_rx_bundle(target, rx_pktq,
  						      &tmp_rxq,
  						      &fetched_pkts,
  						      part_bundle);
  			if (status)
  				goto fail_rx;
  
  			if (!list_empty(rx_pktq))
  				part_bundle = true;
  
  			list_splice_tail_init(&tmp_rxq, comp_pktq);
  		}
  
  		if (!fetched_pkts) {
  			packet = list_first_entry(rx_pktq, struct htc_packet,
  						   list);
  
  			/* fully synchronous */
  			packet->completion = NULL;
  
  			if (!list_is_singular(rx_pktq))
  				/*
  				 * look_aheads in all packet
  				 * except the last one in the
  				 * bundle must be ignored
  				 */
  				packet->info.rx.rx_flags |=
  					HTC_RX_PKT_IGNORE_LOOKAHEAD;
  
  			/* go fetch the packet */
  			status = ath6kl_htc_rx_packet(target, packet,
  						      packet->act_len);
  
  			list_move_tail(&packet->list, &tmp_rxq);
  
  			if (status)
  				goto fail_rx;
  
  			list_splice_tail_init(&tmp_rxq, comp_pktq);
  		}
  	}
  
  	return 0;
  
  fail_rx:
  
  	/*
  	 * Cleanup any packets we allocated but didn't use to
  	 * actually fetch any packets.
  	 */
  
  	list_for_each_entry_safe(packet, tmp_pkt, rx_pktq, list) {
  		list_del(&packet->list);
  		htc_reclaim_rxbuf(target, packet,
  				  &target->endpoint[packet->endpoint]);
  	}
  
  	list_for_each_entry_safe(packet, tmp_pkt, &tmp_rxq, list) {
  		list_del(&packet->list);
  		htc_reclaim_rxbuf(target, packet,
  				  &target->endpoint[packet->endpoint]);
  	}
  
  	return status;
  }
  
  int ath6kl_htc_rxmsg_pending_handler(struct htc_target *target,
  				     u32 msg_look_ahead, int *num_pkts)
  {
  	struct htc_packet *packets, *tmp_pkt;
  	struct htc_endpoint *endpoint;
  	struct list_head rx_pktq, comp_pktq;
  	int status = 0;
  	u32 look_aheads[HTC_HOST_MAX_MSG_PER_BUNDLE];
  	int num_look_ahead = 1;
  	enum htc_endpoint_id id;
  	int n_fetched = 0;
  
  	INIT_LIST_HEAD(&comp_pktq);
  	*num_pkts = 0;
  
  	/*
  	 * On first entry copy the look_aheads into our temp array for
  	 * processing
  	 */
  	look_aheads[0] = msg_look_ahead;
  
  	while (true) {
  		/*
  		 * First lookahead sets the expected endpoint IDs for all
  		 * packets in a bundle.
  		 */
  		id = ((struct htc_frame_hdr *)&look_aheads[0])->eid;
  		endpoint = &target->endpoint[id];
  
  		if (id >= ENDPOINT_MAX) {
  			ath6kl_err("MsgPend, invalid endpoint in look-ahead: %d
  ",
  				   id);
  			status = -ENOMEM;
  			break;
  		}
  
  		INIT_LIST_HEAD(&rx_pktq);
  		INIT_LIST_HEAD(&comp_pktq);
  
  		/*
  		 * Try to allocate as many HTC RX packets indicated by the
  		 * look_aheads.
  		 */
  		status = ath6kl_htc_rx_alloc(target, look_aheads,
  					     num_look_ahead, endpoint,
  					     &rx_pktq);
  		if (status)
  			break;
  
  		if (get_queue_depth(&rx_pktq) >= 2)
  			/*
  			 * A recv bundle was detected, force IRQ status
  			 * re-check again
  			 */
  			target->chk_irq_status_cnt = 1;
  
  		n_fetched += get_queue_depth(&rx_pktq);
  
  		num_look_ahead = 0;
  
  		status = ath6kl_htc_rx_fetch(target, &rx_pktq, &comp_pktq);
  
  		if (!status)
  			ath6kl_htc_rx_chk_water_mark(endpoint);
  
  		/* Process fetched packets */
  		status = ath6kl_htc_rx_process_packets(target, &comp_pktq,
  						       look_aheads,
  						       &num_look_ahead);
  
  		if (!num_look_ahead || status)
  			break;
  
  		/*
  		 * For SYNCH processing, if we get here, we are running
  		 * through the loop again due to a detected lookahead. Set
  		 * flag that we should re-check IRQ status registers again
  		 * before leaving IRQ processing, this can net better
  		 * performance in high throughput situations.
  		 */
  		target->chk_irq_status_cnt = 1;
  	}
  
  	if (status) {
  		ath6kl_err("failed to get pending recv messages: %d
  ",
  			   status);
  
  		/* cleanup any packets in sync completion queue */
  		list_for_each_entry_safe(packets, tmp_pkt, &comp_pktq, list) {
  			list_del(&packets->list);
  			htc_reclaim_rxbuf(target, packets,
  					  &target->endpoint[packets->endpoint]);
  		}
  
  		if (target->htc_flags & HTC_OP_STATE_STOPPING) {
  			ath6kl_warn("host is going to stop blocking receiver for htc_stop
  ");
  			ath6kl_hif_rx_control(target->dev, false);
  		}
  	}
  
  	/*
  	 * Before leaving, check to see if host ran out of buffers and
  	 * needs to stop the receiver.
  	 */
  	if (target->rx_st_flags & HTC_RECV_WAIT_BUFFERS) {
  		ath6kl_warn("host has no rx buffers blocking receiver to prevent overrun
  ");
  		ath6kl_hif_rx_control(target->dev, false);
  	}
  	*num_pkts = n_fetched;
  
  	return status;
  }
  
  /*
   * Synchronously wait for a control message from the target,
   * This function is used at initialization time ONLY.  At init messages
   * on ENDPOINT 0 are expected.
   */
  static struct htc_packet *htc_wait_for_ctrl_msg(struct htc_target *target)
  {
  	struct htc_packet *packet = NULL;
  	struct htc_frame_hdr *htc_hdr;
  	u32 look_ahead;
  
  	if (ath6kl_hif_poll_mboxmsg_rx(target->dev, &look_ahead,
  				       HTC_TARGET_RESPONSE_TIMEOUT))
  		return NULL;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc rx wait ctrl look_ahead 0x%X
  ", look_ahead);
  
  	htc_hdr = (struct htc_frame_hdr *)&look_ahead;
  
  	if (htc_hdr->eid != ENDPOINT_0)
  		return NULL;
  
  	packet = htc_get_control_buf(target, false);
  
  	if (!packet)
  		return NULL;
  
  	packet->info.rx.rx_flags = 0;
  	packet->info.rx.exp_hdr = look_ahead;
  	packet->act_len = le16_to_cpu(htc_hdr->payld_len) + HTC_HDR_LENGTH;
  
  	if (packet->act_len > packet->buf_len)
  		goto fail_ctrl_rx;
  
  	/* we want synchronous operation */
  	packet->completion = NULL;
  
  	/* get the message from the device, this will block */
  	if (ath6kl_htc_rx_packet(target, packet, packet->act_len))
  		goto fail_ctrl_rx;
  
  	trace_ath6kl_htc_rx(packet->status, packet->endpoint,
  			    packet->buf, packet->act_len);
  
  	/* process receive header */
  	packet->status = ath6kl_htc_rx_process_hdr(target, packet, NULL, NULL);
  
  	if (packet->status) {
  		ath6kl_err("htc_wait_for_ctrl_msg, ath6kl_htc_rx_process_hdr failed (status = %d)
  ",
  			   packet->status);
  		goto fail_ctrl_rx;
  	}
  
  	return packet;
  
  fail_ctrl_rx:
  	if (packet != NULL) {
  		htc_rxpkt_reset(packet);
  		reclaim_rx_ctrl_buf(target, packet);
  	}
  
  	return NULL;
  }
  
  static int ath6kl_htc_mbox_add_rxbuf_multiple(struct htc_target *target,
  				  struct list_head *pkt_queue)
  {
  	struct htc_endpoint *endpoint;
  	struct htc_packet *first_pkt;
  	bool rx_unblock = false;
  	int status = 0, depth;
  
  	if (list_empty(pkt_queue))
  		return -ENOMEM;
  
  	first_pkt = list_first_entry(pkt_queue, struct htc_packet, list);
  
  	if (first_pkt->endpoint >= ENDPOINT_MAX)
  		return status;
  
  	depth = get_queue_depth(pkt_queue);
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc rx add multiple ep id %d cnt %d len %d
  ",
  		first_pkt->endpoint, depth, first_pkt->buf_len);
  
  	endpoint = &target->endpoint[first_pkt->endpoint];
  
  	if (target->htc_flags & HTC_OP_STATE_STOPPING) {
  		struct htc_packet *packet, *tmp_pkt;
  
  		/* walk through queue and mark each one canceled */
  		list_for_each_entry_safe(packet, tmp_pkt, pkt_queue, list) {
  			packet->status = -ECANCELED;
  			list_del(&packet->list);
  			ath6kl_htc_rx_complete(endpoint, packet);
  		}
  
  		return status;
  	}
  
  	spin_lock_bh(&target->rx_lock);
  
  	list_splice_tail_init(pkt_queue, &endpoint->rx_bufq);
  
  	/* check if we are blocked waiting for a new buffer */
  	if (target->rx_st_flags & HTC_RECV_WAIT_BUFFERS) {
  		if (target->ep_waiting == first_pkt->endpoint) {
  			ath6kl_dbg(ATH6KL_DBG_HTC,
  				   "htc rx blocked on ep %d, unblocking
  ",
  				   target->ep_waiting);
  			target->rx_st_flags &= ~HTC_RECV_WAIT_BUFFERS;
  			target->ep_waiting = ENDPOINT_MAX;
  			rx_unblock = true;
  		}
  	}
  
  	spin_unlock_bh(&target->rx_lock);
  
  	if (rx_unblock && !(target->htc_flags & HTC_OP_STATE_STOPPING))
  		/* TODO : implement a buffer threshold count? */
  		ath6kl_hif_rx_control(target->dev, true);
  
  	return status;
  }
  
  static void ath6kl_htc_mbox_flush_rx_buf(struct htc_target *target)
  {
  	struct htc_endpoint *endpoint;
  	struct htc_packet *packet, *tmp_pkt;
  	int i;
  
  	for (i = ENDPOINT_0; i < ENDPOINT_MAX; i++) {
  		endpoint = &target->endpoint[i];
  		if (!endpoint->svc_id)
  			/* not in use.. */
  			continue;
  
  		spin_lock_bh(&target->rx_lock);
  		list_for_each_entry_safe(packet, tmp_pkt,
  					 &endpoint->rx_bufq, list) {
  			list_del(&packet->list);
  			spin_unlock_bh(&target->rx_lock);
  			ath6kl_dbg(ATH6KL_DBG_HTC,
  				   "htc rx flush pkt 0x%p  len %d  ep %d
  ",
  				   packet, packet->buf_len,
  				   packet->endpoint);
  			/*
  			 * packets in rx_bufq of endpoint 0 have originally
  			 * been queued from target->free_ctrl_rxbuf where
  			 * packet and packet->buf_start are allocated
  			 * separately using kmalloc(). For other endpoint
  			 * rx_bufq, it is allocated as skb where packet is
  			 * skb->head. Take care of this difference while freeing
  			 * the memory.
  			 */
  			if (packet->endpoint == ENDPOINT_0) {
  				kfree(packet->buf_start);
  				kfree(packet);
  			} else {
  				dev_kfree_skb(packet->pkt_cntxt);
  			}
  			spin_lock_bh(&target->rx_lock);
  		}
  		spin_unlock_bh(&target->rx_lock);
  	}
  }
  
  static int ath6kl_htc_mbox_conn_service(struct htc_target *target,
  			    struct htc_service_connect_req *conn_req,
  			    struct htc_service_connect_resp *conn_resp)
  {
  	struct htc_packet *rx_pkt = NULL;
  	struct htc_packet *tx_pkt = NULL;
  	struct htc_conn_service_resp *resp_msg;
  	struct htc_conn_service_msg *conn_msg;
  	struct htc_endpoint *endpoint;
  	enum htc_endpoint_id assigned_ep = ENDPOINT_MAX;
  	unsigned int max_msg_sz = 0;
  	int status = 0;
  	u16 msg_id;
  
  	ath6kl_dbg(ATH6KL_DBG_HTC,
  		   "htc connect service target 0x%p service id 0x%x
  ",
  		   target, conn_req->svc_id);
  
  	if (conn_req->svc_id == HTC_CTRL_RSVD_SVC) {
  		/* special case for pseudo control service */
  		assigned_ep = ENDPOINT_0;
  		max_msg_sz = HTC_MAX_CTRL_MSG_LEN;
  	} else {
  		/* allocate a packet to send to the target */
  		tx_pkt = htc_get_control_buf(target, true);
  
  		if (!tx_pkt)
  			return -ENOMEM;
  
  		conn_msg = (struct htc_conn_service_msg *)tx_pkt->buf;
  		memset(conn_msg, 0, sizeof(*conn_msg));
  		conn_msg->msg_id = cpu_to_le16(HTC_MSG_CONN_SVC_ID);
  		conn_msg->svc_id = cpu_to_le16(conn_req->svc_id);
  		conn_msg->conn_flags = cpu_to_le16(conn_req->conn_flags);
  
  		set_htc_pkt_info(tx_pkt, NULL, (u8 *) conn_msg,
  				 sizeof(*conn_msg) + conn_msg->svc_meta_len,
  				 ENDPOINT_0, HTC_SERVICE_TX_PACKET_TAG);
  
  		/* we want synchronous operation */
  		tx_pkt->completion = NULL;
  		ath6kl_htc_tx_prep_pkt(tx_pkt, 0, 0, 0);
  		status = ath6kl_htc_tx_issue(target, tx_pkt);
  
  		if (status)
  			goto fail_tx;
  
  		/* wait for response */
  		rx_pkt = htc_wait_for_ctrl_msg(target);
  
  		if (!rx_pkt) {
  			status = -ENOMEM;
  			goto fail_tx;
  		}
  
  		resp_msg = (struct htc_conn_service_resp *)rx_pkt->buf;
  		msg_id = le16_to_cpu(resp_msg->msg_id);
  
  		if ((msg_id != HTC_MSG_CONN_SVC_RESP_ID) ||
  		    (rx_pkt->act_len < sizeof(*resp_msg))) {
  			status = -ENOMEM;
  			goto fail_tx;
  		}
  
  		conn_resp->resp_code = resp_msg->status;
  		/* check response status */
  		if (resp_msg->status != HTC_SERVICE_SUCCESS) {
  			ath6kl_err("target failed service 0x%X connect request (status:%d)
  ",
  				   resp_msg->svc_id, resp_msg->status);
  			status = -ENOMEM;
  			goto fail_tx;
  		}
  
  		assigned_ep = (enum htc_endpoint_id)resp_msg->eid;
  		max_msg_sz = le16_to_cpu(resp_msg->max_msg_sz);
  	}
  
  	if (WARN_ON_ONCE(assigned_ep == ENDPOINT_UNUSED ||
  			 assigned_ep >= ENDPOINT_MAX || !max_msg_sz)) {
  		status = -ENOMEM;
  		goto fail_tx;
  	}
  
  	endpoint = &target->endpoint[assigned_ep];
  	endpoint->eid = assigned_ep;
  	if (endpoint->svc_id) {
  		status = -ENOMEM;
  		goto fail_tx;
  	}
  
  	/* return assigned endpoint to caller */
  	conn_resp->endpoint = assigned_ep;
  	conn_resp->len_max = max_msg_sz;
  
  	/* setup the endpoint */
  
  	/* this marks the endpoint in use */
  	endpoint->svc_id = conn_req->svc_id;
  
  	endpoint->max_txq_depth = conn_req->max_txq_depth;
  	endpoint->len_max = max_msg_sz;
  	endpoint->ep_cb = conn_req->ep_cb;
  	endpoint->cred_dist.svc_id = conn_req->svc_id;
  	endpoint->cred_dist.htc_ep = endpoint;
  	endpoint->cred_dist.endpoint = assigned_ep;
  	endpoint->cred_dist.cred_sz = target->tgt_cred_sz;
  
  	switch (endpoint->svc_id) {
  	case WMI_DATA_BK_SVC:
  		endpoint->tx_drop_packet_threshold = MAX_DEF_COOKIE_NUM / 3;
  		break;
  	default:
  		endpoint->tx_drop_packet_threshold = MAX_HI_COOKIE_NUM;
  		break;
  	}
  
  	if (conn_req->max_rxmsg_sz) {
  		/*
  		 * Override cred_per_msg calculation, this optimizes
  		 * the credit-low indications since the host will actually
  		 * issue smaller messages in the Send path.
  		 */
  		if (conn_req->max_rxmsg_sz > max_msg_sz) {
  			status = -ENOMEM;
  			goto fail_tx;
  		}
  		endpoint->cred_dist.cred_per_msg =
  		    conn_req->max_rxmsg_sz / target->tgt_cred_sz;
  	} else
  		endpoint->cred_dist.cred_per_msg =
  		    max_msg_sz / target->tgt_cred_sz;
  
  	if (!endpoint->cred_dist.cred_per_msg)
  		endpoint->cred_dist.cred_per_msg = 1;
  
  	/* save local connection flags */
  	endpoint->conn_flags = conn_req->flags;
  
  fail_tx:
  	if (tx_pkt)
  		htc_reclaim_txctrl_buf(target, tx_pkt);
  
  	if (rx_pkt) {
  		htc_rxpkt_reset(rx_pkt);
  		reclaim_rx_ctrl_buf(target, rx_pkt);
  	}
  
  	return status;
  }
  
  static void reset_ep_state(struct htc_target *target)
  {
  	struct htc_endpoint *endpoint;
  	int i;
  
  	for (i = ENDPOINT_0; i < ENDPOINT_MAX; i++) {
  		endpoint = &target->endpoint[i];
  		memset(&endpoint->cred_dist, 0, sizeof(endpoint->cred_dist));
  		endpoint->svc_id = 0;
  		endpoint->len_max = 0;
  		endpoint->max_txq_depth = 0;
  		memset(&endpoint->ep_st, 0,
  		       sizeof(endpoint->ep_st));
  		INIT_LIST_HEAD(&endpoint->rx_bufq);
  		INIT_LIST_HEAD(&endpoint->txq);
  		endpoint->target = target;
  	}
  
  	/* reset distribution list */
  	/* FIXME: free existing entries */
  	INIT_LIST_HEAD(&target->cred_dist_list);
  }
  
  static int ath6kl_htc_mbox_get_rxbuf_num(struct htc_target *target,
  			     enum htc_endpoint_id endpoint)
  {
  	int num;
  
  	spin_lock_bh(&target->rx_lock);
  	num = get_queue_depth(&(target->endpoint[endpoint].rx_bufq));
  	spin_unlock_bh(&target->rx_lock);
  	return num;
  }
  
  static void htc_setup_msg_bndl(struct htc_target *target)
  {
  	/* limit what HTC can handle */
  	target->msg_per_bndl_max = min(HTC_HOST_MAX_MSG_PER_BUNDLE,
  				       target->msg_per_bndl_max);
  
  	if (ath6kl_hif_enable_scatter(target->dev->ar)) {
  		target->msg_per_bndl_max = 0;
  		return;
  	}
  
  	/* limit bundle what the device layer can handle */
  	target->msg_per_bndl_max = min(target->max_scat_entries,
  				       target->msg_per_bndl_max);
  
  	ath6kl_dbg(ATH6KL_DBG_BOOT,
  		   "htc bundling allowed msg_per_bndl_max %d
  ",
  		   target->msg_per_bndl_max);
  
  	/* Max rx bundle size is limited by the max tx bundle size */
  	target->max_rx_bndl_sz = target->max_xfer_szper_scatreq;
  	/* Max tx bundle size if limited by the extended mbox address range */
  	target->max_tx_bndl_sz = min(HIF_MBOX0_EXT_WIDTH,
  				     target->max_xfer_szper_scatreq);
  
  	ath6kl_dbg(ATH6KL_DBG_BOOT, "htc max_rx_bndl_sz %d max_tx_bndl_sz %d
  ",
  		   target->max_rx_bndl_sz, target->max_tx_bndl_sz);
  
  	if (target->max_tx_bndl_sz)
  		/* tx_bndl_mask is enabled per AC, each has 1 bit */
  		target->tx_bndl_mask = (1 << WMM_NUM_AC) - 1;
  
  	if (target->max_rx_bndl_sz)
  		target->rx_bndl_enable = true;
  
  	if ((target->tgt_cred_sz % target->block_sz) != 0) {
  		ath6kl_warn("credit size: %d is not block aligned! Disabling send bundling
  ",
  			    target->tgt_cred_sz);
  
  		/*
  		 * Disallow send bundling since the credit size is
  		 * not aligned to a block size the I/O block
  		 * padding will spill into the next credit buffer
  		 * which is fatal.
  		 */
  		target->tx_bndl_mask = 0;
  	}
  }
  
  static int ath6kl_htc_mbox_wait_target(struct htc_target *target)
  {
  	struct htc_packet *packet = NULL;
  	struct htc_ready_ext_msg *rdy_msg;
  	struct htc_service_connect_req connect;
  	struct htc_service_connect_resp resp;
  	int status;
  
  	/* we should be getting 1 control message that the target is ready */
  	packet = htc_wait_for_ctrl_msg(target);
  
  	if (!packet)
  		return -ENOMEM;
  
  	/* we controlled the buffer creation so it's properly aligned */
  	rdy_msg = (struct htc_ready_ext_msg *)packet->buf;
  
  	if ((le16_to_cpu(rdy_msg->ver2_0_info.msg_id) != HTC_MSG_READY_ID) ||
  	    (packet->act_len < sizeof(struct htc_ready_msg))) {
  		status = -ENOMEM;
  		goto fail_wait_target;
  	}
  
  	if (!rdy_msg->ver2_0_info.cred_cnt || !rdy_msg->ver2_0_info.cred_sz) {
  		status = -ENOMEM;
  		goto fail_wait_target;
  	}
  
  	target->tgt_creds = le16_to_cpu(rdy_msg->ver2_0_info.cred_cnt);
  	target->tgt_cred_sz = le16_to_cpu(rdy_msg->ver2_0_info.cred_sz);
  
  	ath6kl_dbg(ATH6KL_DBG_BOOT,
  		   "htc target ready credits %d size %d
  ",
  		   target->tgt_creds, target->tgt_cred_sz);
  
  	/* check if this is an extended ready message */
  	if (packet->act_len >= sizeof(struct htc_ready_ext_msg)) {
  		/* this is an extended message */
  		target->htc_tgt_ver = rdy_msg->htc_ver;
  		target->msg_per_bndl_max = rdy_msg->msg_per_htc_bndl;
  	} else {
  		/* legacy */
  		target->htc_tgt_ver = HTC_VERSION_2P0;
  		target->msg_per_bndl_max = 0;
  	}
  
  	ath6kl_dbg(ATH6KL_DBG_BOOT, "htc using protocol %s (%d)
  ",
  		   (target->htc_tgt_ver == HTC_VERSION_2P0) ? "2.0" : ">= 2.1",
  		   target->htc_tgt_ver);
  
  	if (target->msg_per_bndl_max > 0)
  		htc_setup_msg_bndl(target);
  
  	/* setup our pseudo HTC control endpoint connection */
  	memset(&connect, 0, sizeof(connect));
  	memset(&resp, 0, sizeof(resp));
  	connect.ep_cb.rx = htc_ctrl_rx;
  	connect.ep_cb.rx_refill = NULL;
  	connect.ep_cb.tx_full = NULL;
  	connect.max_txq_depth = NUM_CONTROL_BUFFERS;
  	connect.svc_id = HTC_CTRL_RSVD_SVC;
  
  	/* connect fake service */
  	status = ath6kl_htc_mbox_conn_service((void *)target, &connect, &resp);
  
  	if (status)
  		/*
  		 * FIXME: this call doesn't make sense, the caller should
  		 * call ath6kl_htc_mbox_cleanup() when it wants remove htc
  		 */
  		ath6kl_hif_cleanup_scatter(target->dev->ar);
  
  fail_wait_target:
  	if (packet) {
  		htc_rxpkt_reset(packet);
  		reclaim_rx_ctrl_buf(target, packet);
  	}
  
  	return status;
  }
  
  /*
   * Start HTC, enable interrupts and let the target know
   * host has finished setup.
   */
  static int ath6kl_htc_mbox_start(struct htc_target *target)
  {
  	struct htc_packet *packet;
  	int status;
  
  	memset(&target->dev->irq_proc_reg, 0,
  	       sizeof(target->dev->irq_proc_reg));
  
  	/* Disable interrupts at the chip level */
  	ath6kl_hif_disable_intrs(target->dev);
  
  	target->htc_flags = 0;
  	target->rx_st_flags = 0;
  
  	/* Push control receive buffers into htc control endpoint */
  	while ((packet = htc_get_control_buf(target, false)) != NULL) {
  		status = htc_add_rxbuf(target, packet);
  		if (status)
  			return status;
  	}
  
  	/* NOTE: the first entry in the distribution list is ENDPOINT_0 */
  	ath6kl_credit_init(target->credit_info, &target->cred_dist_list,
  			   target->tgt_creds);
  
  	dump_cred_dist_stats(target);
  
  	/* Indicate to the target of the setup completion */
  	status = htc_setup_tx_complete(target);
  
  	if (status)
  		return status;
  
  	/* unmask interrupts */
  	status = ath6kl_hif_unmask_intrs(target->dev);
  
  	if (status)
  		ath6kl_htc_mbox_stop(target);
  
  	return status;
  }
  
  static int ath6kl_htc_reset(struct htc_target *target)
  {
  	u32 block_size, ctrl_bufsz;
  	struct htc_packet *packet;
  	int i;
  
  	reset_ep_state(target);
  
  	block_size = target->dev->ar->mbox_info.block_size;
  
  	ctrl_bufsz = (block_size > HTC_MAX_CTRL_MSG_LEN) ?
  		      (block_size + HTC_HDR_LENGTH) :
  		      (HTC_MAX_CTRL_MSG_LEN + HTC_HDR_LENGTH);
  
  	for (i = 0; i < NUM_CONTROL_BUFFERS; i++) {
  		packet = kzalloc(sizeof(*packet), GFP_KERNEL);
  		if (!packet)
  			return -ENOMEM;
  
  		packet->buf_start = kzalloc(ctrl_bufsz, GFP_KERNEL);
  		if (!packet->buf_start) {
  			kfree(packet);
  			return -ENOMEM;
  		}
  
  		packet->buf_len = ctrl_bufsz;
  		if (i < NUM_CONTROL_RX_BUFFERS) {
  			packet->act_len = 0;
  			packet->buf = packet->buf_start;
  			packet->endpoint = ENDPOINT_0;
  			list_add_tail(&packet->list, &target->free_ctrl_rxbuf);
  		} else {
  			list_add_tail(&packet->list, &target->free_ctrl_txbuf);
  		}
  	}
  
  	return 0;
  }
  
  /* htc_stop: stop interrupt reception, and flush all queued buffers */
  static void ath6kl_htc_mbox_stop(struct htc_target *target)
  {
  	spin_lock_bh(&target->htc_lock);
  	target->htc_flags |= HTC_OP_STATE_STOPPING;
  	spin_unlock_bh(&target->htc_lock);
  
  	/*
  	 * Masking interrupts is a synchronous operation, when this
  	 * function returns all pending HIF I/O has completed, we can
  	 * safely flush the queues.
  	 */
  	ath6kl_hif_mask_intrs(target->dev);
  
  	ath6kl_htc_flush_txep_all(target);
  
  	ath6kl_htc_mbox_flush_rx_buf(target);
  
  	ath6kl_htc_reset(target);
  }
  
  static void *ath6kl_htc_mbox_create(struct ath6kl *ar)
  {
  	struct htc_target *target = NULL;
  	int status = 0;
  
  	target = kzalloc(sizeof(*target), GFP_KERNEL);
  	if (!target) {
  		ath6kl_err("unable to allocate memory
  ");
  		return NULL;
  	}
  
  	target->dev = kzalloc(sizeof(*target->dev), GFP_KERNEL);
  	if (!target->dev) {
  		ath6kl_err("unable to allocate memory
  ");
  		status = -ENOMEM;
  		goto err_htc_cleanup;
  	}
  
  	spin_lock_init(&target->htc_lock);
  	spin_lock_init(&target->rx_lock);
  	spin_lock_init(&target->tx_lock);
  
  	INIT_LIST_HEAD(&target->free_ctrl_txbuf);
  	INIT_LIST_HEAD(&target->free_ctrl_rxbuf);
  	INIT_LIST_HEAD(&target->cred_dist_list);
  
  	target->dev->ar = ar;
  	target->dev->htc_cnxt = target;
  	target->ep_waiting = ENDPOINT_MAX;
  
  	status = ath6kl_hif_setup(target->dev);
  	if (status)
  		goto err_htc_cleanup;
  
  	status = ath6kl_htc_reset(target);
  	if (status)
  		goto err_htc_cleanup;
  
  	return target;
  
  err_htc_cleanup:
  	ath6kl_htc_mbox_cleanup(target);
  
  	return NULL;
  }
  
  /* cleanup the HTC instance */
  static void ath6kl_htc_mbox_cleanup(struct htc_target *target)
  {
  	struct htc_packet *packet, *tmp_packet;
  
  	ath6kl_hif_cleanup_scatter(target->dev->ar);
  
  	list_for_each_entry_safe(packet, tmp_packet,
  				 &target->free_ctrl_txbuf, list) {
  		list_del(&packet->list);
  		kfree(packet->buf_start);
  		kfree(packet);
  	}
  
  	list_for_each_entry_safe(packet, tmp_packet,
  				 &target->free_ctrl_rxbuf, list) {
  		list_del(&packet->list);
  		kfree(packet->buf_start);
  		kfree(packet);
  	}
  
  	kfree(target->dev);
  	kfree(target);
  }
  
  static const struct ath6kl_htc_ops ath6kl_htc_mbox_ops = {
  	.create = ath6kl_htc_mbox_create,
  	.wait_target = ath6kl_htc_mbox_wait_target,
  	.start = ath6kl_htc_mbox_start,
  	.conn_service = ath6kl_htc_mbox_conn_service,
  	.tx = ath6kl_htc_mbox_tx,
  	.stop = ath6kl_htc_mbox_stop,
  	.cleanup = ath6kl_htc_mbox_cleanup,
  	.flush_txep = ath6kl_htc_mbox_flush_txep,
  	.flush_rx_buf = ath6kl_htc_mbox_flush_rx_buf,
  	.activity_changed = ath6kl_htc_mbox_activity_changed,
  	.get_rxbuf_num = ath6kl_htc_mbox_get_rxbuf_num,
  	.add_rxbuf_multiple = ath6kl_htc_mbox_add_rxbuf_multiple,
  	.credit_setup = ath6kl_htc_mbox_credit_setup,
  };
  
  void ath6kl_htc_mbox_attach(struct ath6kl *ar)
  {
  	ar->htc_ops = &ath6kl_htc_mbox_ops;
  }