qcacld-3.0: Borrow credits from other txq group

In case the current selected txq group, does not have enough credits,
try to borrow credits from the other txq group.

Change-Id: I86fbe990853d90598f6e09b13f7061e4ba1a78ae
CRs-fixed: 2246206

core/dp/txrx/ol_tx_queue.c

@@ -1748,6 +1748,93 @@ ol_tx_ac_has_tx_queue_group(
 	return false;
 }
 
+#ifdef FEATURE_HL_DBS_GROUP_CREDIT_SHARING
+static inline struct ol_tx_queue_group_t *
+ol_tx_txq_find_other_group(struct ol_txrx_pdev_t *pdev,
+			   struct ol_tx_queue_group_t *txq_grp)
+{
+	int i;
+	struct ol_tx_queue_group_t *other_grp = NULL;
+
+	for (i = 0; i < OL_TX_MAX_TXQ_GROUPS; i++) {
+		if (&pdev->txq_grps[i] != txq_grp) {
+			other_grp = &pdev->txq_grps[i];
+			break;
+		}
+	}
+	return other_grp;
+}
+
+u32 ol_tx_txq_group_credit_limit(
+	struct ol_txrx_pdev_t *pdev,
+	struct ol_tx_frms_queue_t *txq,
+	u32 credit)
+{
+	struct ol_tx_queue_group_t *txq_grp = txq->group_ptrs[0];
+	struct ol_tx_queue_group_t *other_grp;
+	u32 ask;
+	u32 updated_credit;
+	u32 credit_oth_grp;
+
+	if (qdf_unlikely(!txq_grp))
+		return credit;
+
+	updated_credit = qdf_atomic_read(&txq_grp->credit);
+
+	if (credit <= updated_credit)
+		/* We have enough credits */
+		return credit;
+
+	ask = credit - updated_credit;
+	other_grp = ol_tx_txq_find_other_group(pdev, txq_grp);
+	if (qdf_unlikely(!other_grp))
+		return credit;
+
+	credit_oth_grp = qdf_atomic_read(&other_grp->credit);
+	if (other_grp->frm_count < credit_oth_grp) {
+		u32 spare = credit_oth_grp - other_grp->frm_count;
+
+		if (pdev->limit_lend) {
+			if (spare > pdev->min_reserve)
+				spare -= pdev->min_reserve;
+			else
+				spare = 0;
+		}
+		updated_credit += min(spare, ask);
+	}
+	return updated_credit;
+}
+
+u32 ol_tx_txq_update_borrowed_group_credits(struct ol_txrx_pdev_t *pdev,
+					    struct ol_tx_frms_queue_t *txq,
+					    u32 credits_used)
+{
+	struct ol_tx_queue_group_t *txq_grp = txq->group_ptrs[0];
+	u32 credits_cur_grp;
+	u32 credits_brwd;
+
+	if (qdf_unlikely(!txq_grp))
+		return credits_used;
+
+	credits_cur_grp = qdf_atomic_read(&txq_grp->credit);
+	if (credits_used > credits_cur_grp) {
+		struct ol_tx_queue_group_t *other_grp =
+			ol_tx_txq_find_other_group(pdev, txq_grp);
+
+		if (qdf_likely(other_grp)) {
+			credits_brwd = credits_used - credits_cur_grp;
+			/*
+			 * All the credits were used from the active txq group.
+			 */
+			credits_used = credits_cur_grp;
+			/* Deduct credits borrowed from other group */
+			ol_txrx_update_group_credit(other_grp, -credits_brwd,
+						    0);
+		}
+	}
+	return credits_used;
+}
+#else /* FEATURE_HL_DBS_GROUP_CREDIT_SHARING */
 u_int32_t ol_tx_txq_group_credit_limit(
 	struct ol_txrx_pdev_t *pdev,
 	struct ol_tx_frms_queue_t *txq,
@@ -1774,6 +1861,7 @@ u_int32_t ol_tx_txq_group_credit_limit(
 
 	return credit;
 }
+#endif /* FEATURE_HL_DBS_GROUP_CREDIT_SHARING */
 
 void ol_tx_txq_group_credit_update(
 	struct ol_txrx_pdev_t *pdev,

core/dp/txrx/ol_tx_queue.h

@@ -456,7 +456,6 @@ static inline void ol_tx_throttle_init_period(struct cdp_pdev *ppdev,
 #endif
 
 #ifdef FEATURE_HL_GROUP_CREDIT_FLOW_CONTROL
-
 static inline bool
 ol_tx_is_txq_last_serviced_queue(struct ol_txrx_pdev_t *pdev,
 				 struct ol_tx_frms_queue_t *txq)
@@ -592,10 +591,22 @@ ol_tx_set_peer_group_ptr(
  * @param: num_frms - Number of frames to be added/removed from the group.
  */
 void ol_tx_update_grp_frm_count(struct ol_tx_frms_queue_t *txq, int num_frms);
+
+u32 ol_tx_txq_update_borrowed_group_credits(struct ol_txrx_pdev_t *pdev,
+					    struct ol_tx_frms_queue_t *txq,
+					    u32 credits_used);
 #else
 static inline void ol_tx_update_grp_frm_count(struct ol_tx_frms_queue_t *txq,
 					      int num_frms)
 {}
+
+static inline u32
+ol_tx_txq_update_borrowed_group_credits(struct ol_txrx_pdev_t *pdev,
+					struct ol_tx_frms_queue_t *txq,
+					u32 credits_used)
+{
+	return credits_used;
+}
 #endif /*
 	* FEATURE_HL_GROUP_CREDIT_FLOW_CONTROL &&
 	*  FEATURE_HL_DBS_GROUP_CREDIT_SHARING

core/dp/txrx/ol_tx_sched.c

@@ -842,7 +842,11 @@ ol_tx_sched_select_batch_wrr_adv(
 
 			OL_TX_SCHED_WRR_ADV_CAT_STAT_INC_DISPATCHED(category,
 								    frames);
+			/* Update used global credits */
 			used_credits = credit;
+			credit =
+			ol_tx_txq_update_borrowed_group_credits(pdev, txq,
+								credit);
 			category->state.frms -= frames;
 			category->state.bytes -= bytes;
 			if (txq->frms > 0) {

core/dp/txrx/ol_txrx.c

@@ -1473,6 +1473,8 @@ ol_txrx_pdev_post_attach(struct cdp_pdev *ppdev)
 		for (i = 0 ; i < OL_TX_MAX_TXQ_GROUPS; i++)
 			qdf_atomic_init(&pdev->txq_grps[i].credit);
 
+		ol_txrx_init_txq_group_limit_lend(pdev);
+
 		ol_tx_target_credit_init(pdev, desc_pool_size);
 	} else {
 		qdf_atomic_add(ol_cfg_target_tx_credit(pdev->ctrl_pdev),

core/dp/txrx/ol_txrx.h

@@ -210,4 +210,21 @@ bool ol_txrx_fwd_desc_thresh_check(struct ol_txrx_vdev_t *vdev)
 }
 
 #endif
+
+#if defined(FEATURE_HL_GROUP_CREDIT_FLOW_CONTROL) && \
+	defined(FEATURE_HL_DBS_GROUP_CREDIT_SHARING)
+static inline void
+ol_txrx_init_txq_group_limit_lend(struct ol_txrx_pdev_t *pdev)
+{
+	BUILD_BUG_ON(OL_TX_MAX_GROUPS_PER_QUEUE > 1);
+	BUILD_BUG_ON(OL_TX_MAX_TXQ_GROUPS > 2);
+	pdev->limit_lend = 0;
+	pdev->min_reserve = 0;
+}
+#else
+static inline void
+ol_txrx_init_txq_group_limit_lend(struct ol_txrx_pdev_t *pdev)
+{}
+#endif
+
 #endif /* _OL_TXRX__H_ */

core/dp/txrx/ol_txrx_types.h

@@ -995,6 +995,11 @@ struct ol_txrx_pdev_t {
 #endif /* CONFIG_Hl_SUPPORT && QCA_BAD_PEER_TX_FLOW_CL */
 
 	struct ol_tx_queue_group_t txq_grps[OL_TX_MAX_TXQ_GROUPS];
+#if defined(FEATURE_HL_GROUP_CREDIT_FLOW_CONTROL) && \
+	defined(FEATURE_HL_DBS_GROUP_CREDIT_SHARING)
+	bool limit_lend;
+	u16 min_reserve;
+#endif
 #ifdef DEBUG_HL_LOGGING
 		qdf_spinlock_t grp_stat_spinlock;
 		struct ol_tx_group_credit_stats_t grp_stats;