be2net: fix adaptive interrupt coalescing

The current EQ delay calculation for AIC is based only on RX packet rate.
This fails to be effective when there's only TX and no RX.
This patch inclues:
- Calculating EQ-delay based on both RX and TX pps.
- Modifying EQ-delay of all EQs via one cmd, instead of issuing a separate
  cmd for each EQ.
- A new structure to store interrupt coalescing parameters, in a separate
  cache-line from the EQ-obj.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be.h

@@ -88,7 +88,7 @@ static inline char *nic_name(struct pci_dev *pdev)
 #define BE_MIN_MTU		256
 
 #define BE_NUM_VLANS_SUPPORTED	64
-#define BE_MAX_EQD		96u
+#define BE_MAX_EQD		128u
 #define	BE_MAX_TX_FRAG_COUNT	30
 
 #define EVNT_Q_LEN		1024
@@ -200,6 +200,17 @@ struct be_eq_obj {
 	struct be_adapter *adapter;
 } ____cacheline_aligned_in_smp;
 
+struct be_aic_obj {		/* Adaptive interrupt coalescing (AIC) info */
+	bool enable;
+	u32 min_eqd;		/* in usecs */
+	u32 max_eqd;		/* in usecs */
+	u32 prev_eqd;		/* in usecs */
+	u32 et_eqd;		/* configured val when aic is off */
+	ulong jiffies;
+	u64 rx_pkts_prev;	/* Used to calculate RX pps */
+	u64 tx_reqs_prev;	/* Used to calculate TX pps */
+};
+
 struct be_mcc_obj {
 	struct be_queue_info q;
 	struct be_queue_info cq;
@@ -238,15 +249,12 @@ struct be_rx_page_info {
 struct be_rx_stats {
 	u64 rx_bytes;
 	u64 rx_pkts;
-	u64 rx_pkts_prev;
-	ulong rx_jiffies;
 	u32 rx_drops_no_skbs;	/* skb allocation errors */
 	u32 rx_drops_no_frags;	/* HW has no fetched frags */
 	u32 rx_post_fail;	/* page post alloc failures */
 	u32 rx_compl;
 	u32 rx_mcast_pkts;
 	u32 rx_compl_err;	/* completions with err set */
-	u32 rx_pps;		/* pkts per second */
 	struct u64_stats_sync sync;
 };
 
@@ -403,6 +411,7 @@ struct be_adapter {
 	u32 big_page_size;	/* Compounded page size shared by rx wrbs */
 
 	struct be_drv_stats drv_stats;
+	struct be_aic_obj aic_obj[MAX_EVT_QS];
 	u16 vlans_added;
 	u8 vlan_tag[VLAN_N_VID];
 	u8 vlan_prio_bmap;	/* Available Priority BitMap */

drivers/net/ethernet/emulex/benet/be_cmds.c

@@ -1716,11 +1716,12 @@ err:
 /* set the EQ delay interval of an EQ to specified value
  * Uses async mcc
  */
-int be_cmd_modify_eqd(struct be_adapter *adapter, u32 eq_id, u32 eqd)
+int be_cmd_modify_eqd(struct be_adapter *adapter, struct be_set_eqd *set_eqd,
+		      int num)
 {
 	struct be_mcc_wrb *wrb;
 	struct be_cmd_req_modify_eq_delay *req;
-	int status = 0;
+	int status = 0, i;
 
 	spin_lock_bh(&adapter->mcc_lock);
 
@@ -1734,13 +1735,15 @@ int be_cmd_modify_eqd(struct be_adapter *adapter, u32 eq_id, u32 eqd)
 	be_wrb_cmd_hdr_prepare(&req->hdr, CMD_SUBSYSTEM_COMMON,
 		OPCODE_COMMON_MODIFY_EQ_DELAY, sizeof(*req), wrb, NULL);
 
-	req->num_eq = cpu_to_le32(1);
-	req->delay[0].eq_id = cpu_to_le32(eq_id);
-	req->delay[0].phase = 0;
-	req->delay[0].delay_multiplier = cpu_to_le32(eqd);
+	req->num_eq = cpu_to_le32(num);
+	for (i = 0; i < num; i++) {
+		req->set_eqd[i].eq_id = cpu_to_le32(set_eqd[i].eq_id);
+		req->set_eqd[i].phase = 0;
+		req->set_eqd[i].delay_multiplier =
+				cpu_to_le32(set_eqd[i].delay_multiplier);
+	}
 
 	be_mcc_notify(adapter);
-
 err:
 	spin_unlock_bh(&adapter->mcc_lock);
 	return status;

drivers/net/ethernet/emulex/benet/be_cmds.h

@@ -1055,14 +1055,16 @@ struct be_cmd_resp_get_flow_control {
 } __packed;
 
 /******************** Modify EQ Delay *******************/
+struct be_set_eqd {
+	u32 eq_id;
+	u32 phase;
+	u32 delay_multiplier;
+};
+
 struct be_cmd_req_modify_eq_delay {
 	struct be_cmd_req_hdr hdr;
 	u32 num_eq;
-	struct {
-		u32 eq_id;
-		u32 phase;
-		u32 delay_multiplier;
-	} delay[8];
+	struct be_set_eqd set_eqd[MAX_EVT_QS];
 } __packed;
 
 struct be_cmd_resp_modify_eq_delay {
@@ -1894,8 +1896,7 @@ int lancer_cmd_get_pport_stats(struct be_adapter *adapter,
 			       struct be_dma_mem *nonemb_cmd);
 int be_cmd_get_fw_ver(struct be_adapter *adapter, char *fw_ver,
 		      char *fw_on_flash);
-
-int be_cmd_modify_eqd(struct be_adapter *adapter, u32 eq_id, u32 eqd);
+int be_cmd_modify_eqd(struct be_adapter *adapter, struct be_set_eqd *, int num);
 int be_cmd_vlan_config(struct be_adapter *adapter, u32 if_id, u16 *vtag_array,
 		       u32 num, bool untagged, bool promiscuous);
 int be_cmd_rx_filter(struct be_adapter *adapter, u32 flags, u32 status);

drivers/net/ethernet/emulex/benet/be_ethtool.c

@@ -290,19 +290,19 @@ static int be_get_coalesce(struct net_device *netdev,
 			   struct ethtool_coalesce *et)
 {
 	struct be_adapter *adapter = netdev_priv(netdev);
-	struct be_eq_obj *eqo = &adapter->eq_obj[0];
+	struct be_aic_obj *aic = &adapter->aic_obj[0];
 
 
-	et->rx_coalesce_usecs = eqo->cur_eqd;
-	et->rx_coalesce_usecs_high = eqo->max_eqd;
-	et->rx_coalesce_usecs_low = eqo->min_eqd;
+	et->rx_coalesce_usecs = aic->prev_eqd;
+	et->rx_coalesce_usecs_high = aic->max_eqd;
+	et->rx_coalesce_usecs_low = aic->min_eqd;
 
-	et->tx_coalesce_usecs = eqo->cur_eqd;
-	et->tx_coalesce_usecs_high = eqo->max_eqd;
-	et->tx_coalesce_usecs_low = eqo->min_eqd;
+	et->tx_coalesce_usecs = aic->prev_eqd;
+	et->tx_coalesce_usecs_high = aic->max_eqd;
+	et->tx_coalesce_usecs_low = aic->min_eqd;
 
-	et->use_adaptive_rx_coalesce = eqo->enable_aic;
-	et->use_adaptive_tx_coalesce = eqo->enable_aic;
+	et->use_adaptive_rx_coalesce = aic->enable;
+	et->use_adaptive_tx_coalesce = aic->enable;
 
 	return 0;
 }
@@ -314,14 +314,17 @@ static int be_set_coalesce(struct net_device *netdev,
 			   struct ethtool_coalesce *et)
 {
 	struct be_adapter *adapter = netdev_priv(netdev);
+	struct be_aic_obj *aic = &adapter->aic_obj[0];
 	struct be_eq_obj *eqo;
 	int i;
 
 	for_all_evt_queues(adapter, eqo, i) {
-		eqo->enable_aic = et->use_adaptive_rx_coalesce;
-		eqo->max_eqd = min(et->rx_coalesce_usecs_high, BE_MAX_EQD);
-		eqo->min_eqd = min(et->rx_coalesce_usecs_low, eqo->max_eqd);
-		eqo->eqd = et->rx_coalesce_usecs;
+		aic->enable = et->use_adaptive_rx_coalesce;
+		aic->max_eqd = min(et->rx_coalesce_usecs_high, BE_MAX_EQD);
+		aic->min_eqd = min(et->rx_coalesce_usecs_low, aic->max_eqd);
+		aic->et_eqd = min(et->rx_coalesce_usecs, aic->max_eqd);
+		aic->et_eqd = max(aic->et_eqd, aic->min_eqd);
+		aic++;
 	}
 
 	return 0;

drivers/net/ethernet/emulex/benet/be_main.c

@@ -1261,53 +1261,79 @@ static int be_set_vf_tx_rate(struct net_device *netdev,
 	return status;
 }
 
-static void be_eqd_update(struct be_adapter *adapter, struct be_eq_obj *eqo)
+static void be_aic_update(struct be_aic_obj *aic, u64 rx_pkts, u64 tx_pkts,
+			  ulong now)
 {
-	struct be_rx_stats *stats = rx_stats(&adapter->rx_obj[eqo->idx]);
-	ulong now = jiffies;
-	ulong delta = now - stats->rx_jiffies;
-	u64 pkts;
-	unsigned int start, eqd;
+	aic->rx_pkts_prev = rx_pkts;
+	aic->tx_reqs_prev = tx_pkts;
+	aic->jiffies = now;
+}
 
-	if (!eqo->enable_aic) {
-		eqd = eqo->eqd;
-		goto modify_eqd;
-	}
+static void be_eqd_update(struct be_adapter *adapter)
+{
+	struct be_set_eqd set_eqd[MAX_EVT_QS];
+	int eqd, i, num = 0, start;
+	struct be_aic_obj *aic;
+	struct be_eq_obj *eqo;
+	struct be_rx_obj *rxo;
+	struct be_tx_obj *txo;
+	u64 rx_pkts, tx_pkts;
+	ulong now;
+	u32 pps, delta;
 
-	if (eqo->idx >= adapter->num_rx_qs)
-		return;
+	for_all_evt_queues(adapter, eqo, i) {
+		aic = &adapter->aic_obj[eqo->idx];
+		if (!aic->enable) {
+			if (aic->jiffies)
+				aic->jiffies = 0;
+			eqd = aic->et_eqd;
+			goto modify_eqd;
+		}
 
-	stats = rx_stats(&adapter->rx_obj[eqo->idx]);
+		rxo = &adapter->rx_obj[eqo->idx];
+		do {
+			start = u64_stats_fetch_begin_bh(&rxo->stats.sync);
+			rx_pkts = rxo->stats.rx_pkts;
+		} while (u64_stats_fetch_retry_bh(&rxo->stats.sync, start));
 
-	/* Wrapped around */
-	if (time_before(now, stats->rx_jiffies)) {
-		stats->rx_jiffies = now;
-		return;
-	}
+		txo = &adapter->tx_obj[eqo->idx];
+		do {
+			start = u64_stats_fetch_begin_bh(&txo->stats.sync);
+			tx_pkts = txo->stats.tx_reqs;
+		} while (u64_stats_fetch_retry_bh(&txo->stats.sync, start));
 
-	/* Update once a second */
-	if (delta < HZ)
-		return;
 
-	do {
-		start = u64_stats_fetch_begin_bh(&stats->sync);
-		pkts = stats->rx_pkts;
-	} while (u64_stats_fetch_retry_bh(&stats->sync, start));
+		/* Skip, if wrapped around or first calculation */
+		now = jiffies;
+		if (!aic->jiffies || time_before(now, aic->jiffies) ||
+		    rx_pkts < aic->rx_pkts_prev ||
+		    tx_pkts < aic->tx_reqs_prev) {
+			be_aic_update(aic, rx_pkts, tx_pkts, now);
+			continue;
+		}
 
-	stats->rx_pps = (unsigned long)(pkts - stats->rx_pkts_prev) / (delta / HZ);
-	stats->rx_pkts_prev = pkts;
-	stats->rx_jiffies = now;
-	eqd = (stats->rx_pps / 110000) << 3;
-	eqd = min(eqd, eqo->max_eqd);
-	eqd = max(eqd, eqo->min_eqd);
-	if (eqd < 10)
-		eqd = 0;
+		delta = jiffies_to_msecs(now - aic->jiffies);
+		pps = (((u32)(rx_pkts - aic->rx_pkts_prev) * 1000) / delta) +
+			(((u32)(tx_pkts - aic->tx_reqs_prev) * 1000) / delta);
+		eqd = (pps / 15000) << 2;
 
+		if (eqd < 8)
+			eqd = 0;
+		eqd = min_t(u32, eqd, aic->max_eqd);
+		eqd = max_t(u32, eqd, aic->min_eqd);
+
+		be_aic_update(aic, rx_pkts, tx_pkts, now);
 modify_eqd:
-	if (eqd != eqo->cur_eqd) {
-		be_cmd_modify_eqd(adapter, eqo->q.id, eqd);
-		eqo->cur_eqd = eqd;
+		if (eqd != aic->prev_eqd) {
+			set_eqd[num].delay_multiplier = (eqd * 65)/100;
+			set_eqd[num].eq_id = eqo->q.id;
+			aic->prev_eqd = eqd;
+			num++;
+		}
 	}
+
+	if (num)
+		be_cmd_modify_eqd(adapter, set_eqd, num);
 }
 
 static void be_rx_stats_update(struct be_rx_obj *rxo,
@@ -1924,6 +1950,7 @@ static int be_evt_queues_create(struct be_adapter *adapter)
 {
 	struct be_queue_info *eq;
 	struct be_eq_obj *eqo;
+	struct be_aic_obj *aic;
 	int i, rc;
 
 	adapter->num_evt_qs = min_t(u16, num_irqs(adapter),
@@ -1932,11 +1959,12 @@ static int be_evt_queues_create(struct be_adapter *adapter)
 	for_all_evt_queues(adapter, eqo, i) {
 		netif_napi_add(adapter->netdev, &eqo->napi, be_poll,
 			       BE_NAPI_WEIGHT);
+		aic = &adapter->aic_obj[i];
 		eqo->adapter = adapter;
 		eqo->tx_budget = BE_TX_BUDGET;
 		eqo->idx = i;
-		eqo->max_eqd = BE_MAX_EQD;
-		eqo->enable_aic = true;
+		aic->max_eqd = BE_MAX_EQD;
+		aic->enable = true;
 
 		eq = &eqo->q;
 		rc = be_queue_alloc(adapter, eq, EVNT_Q_LEN,
@@ -4240,7 +4268,6 @@ static void be_worker(struct work_struct *work)
 	struct be_adapter *adapter =
 		container_of(work, struct be_adapter, work.work);
 	struct be_rx_obj *rxo;
-	struct be_eq_obj *eqo;
 	int i;
 
 	/* when interrupts are not yet enabled, just reap any pending
@@ -4271,8 +4298,7 @@ static void be_worker(struct work_struct *work)
 		}
 	}
 
-	for_all_evt_queues(adapter, eqo, i)
-		be_eqd_update(adapter, eqo);
+	be_eqd_update(adapter);
 
 reschedule:
 	adapter->work_counter++;