ath6kl: move all credit distribution code to htc.c

As htc is the only user there's no reason to keep it in main.c.

No functional changes.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 292 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/htc.c b/drivers/net/wireless/ath/ath6kl/htc.c
index 24dfc02225c..5cb03272255 100644
--- a/drivers/net/wireless/ath/ath6kl/htc.c
+++ b/drivers/net/wireless/ath/ath6kl/htc.c
@@ -22,6 +22,298 @@
 
 #define CALC_TXRX_PADDED_LEN(dev, len)  (__ALIGN_MASK((len), (dev)->block_mask))
 
+/* Functions for Tx credit handling */
+static void ath6kl_deposit_credit_to_ep(struct ath6kl_htc_credit_info
+					*cred_info,
+					struct htc_endpoint_credit_dist
+					*ep_dist, int 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;
+
+	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_deposit_credit_to_ep(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_deposit_credit_to_ep(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;
+		} else if (cur_ep_dist->svc_id == WMI_DATA_BK_SVC)
+			/* this is the lowest priority data endpoint */
+			/* FIXME: this looks fishy, check */
+			cred_info->lowestpri_ep_dist = cur_ep_dist->list;
+
+		/*
+		 * 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
+		 */
+	}
+
+	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;
+
+		}
+	}
+}
+
+/* initialize and setup credit distribution */
+int ath6kl_setup_credit_dist(void *htc_handle,
+			     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_handle, cred_info, servicepriority, 5);
+
+	return 0;
+}
+
+/* reduce an ep's credits back to a set limit */
+static void ath6kl_reduce_credits(struct ath6kl_htc_credit_info *cred_info,
+				  struct htc_endpoint_credit_dist *ep_dist,
+				  int limit)
+{
+	int credits;
+
+	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_dist_list;
+
+	list_for_each_entry(cur_dist_list, epdist_list, list) {
+		if (cur_dist_list->endpoint == ENDPOINT_0)
+			continue;
+
+		if (cur_dist_list->cred_to_dist > 0) {
+			cur_dist_list->credits +=
+					cur_dist_list->cred_to_dist;
+			cur_dist_list->cred_to_dist = 0;
+			if (cur_dist_list->credits >
+			    cur_dist_list->cred_assngd)
+				ath6kl_reduce_credits(cred_info,
+						cur_dist_list,
+						cur_dist_list->cred_assngd);
+
+			if (cur_dist_list->credits >
+			    cur_dist_list->cred_norm)
+				ath6kl_reduce_credits(cred_info, cur_dist_list,
+						      cur_dist_list->cred_norm);
+
+			if (!(cur_dist_list->dist_flags & HTC_EP_ACTIVE)) {
+				if (cur_dist_list->txq_depth == 0)
+					ath6kl_reduce_credits(cred_info,
+							      cur_dist_list, 0);
+			}
+		}
+	}
+}
+
+/*
+ * HTC has an endpoint that needs credits, ep_dist is the endpoint in
+ * question.
+ */
+static void ath6kl_seek_credits(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_reduce_credits(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_deposit_credit_to_ep(cred_info, ep_dist, credits);
+
+	ep_dist->seek_cred = 0;
+}
+
+/* redistribute credits based on activity change */
+static void ath6kl_redistribute_credits(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_reduce_credits(info, curdist_list, 0);
+			else
+				ath6kl_reduce_credits(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_redistribute_credits(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;