From: Intel <intel.com>
Date: Mon, 22 Jul 2013 22:00:00 +0000 (+0200)
Subject: igb: use DD bit to count RX available descriptors
X-Git-Tag: spdx-start~11175
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=0f6b7c7f7a3752983a30cd9fb7fb1ffe3c3f4205;p=dpdk.git

igb: use DD bit to count RX available descriptors

Signed-off-by: Intel
---

diff --git a/lib/librte_pmd_e1000/em_ethdev.c b/lib/librte_pmd_e1000/em_ethdev.c
index 7c6bf77ad4..dd73e22ba8 100644
--- a/lib/librte_pmd_e1000/em_ethdev.c
+++ b/lib/librte_pmd_e1000/em_ethdev.c
@@ -147,7 +147,7 @@ static struct eth_dev_ops eth_em_ops = {
 	.vlan_offload_set     = eth_em_vlan_offload_set,
 	.rx_queue_setup       = eth_em_rx_queue_setup,
 	.rx_queue_release     = eth_em_rx_queue_release,
-	.rx_queue_count       = eth_em_rx_queue_count,	
+	.rx_queue_count       = eth_em_rx_queue_count,
 	.tx_queue_setup       = eth_em_tx_queue_setup,
 	.tx_queue_release     = eth_em_tx_queue_release,
 	.dev_led_on           = eth_em_led_on,
diff --git a/lib/librte_pmd_e1000/em_rxtx.c b/lib/librte_pmd_e1000/em_rxtx.c
index b63071f607..a6b2acd3ba 100644
--- a/lib/librte_pmd_e1000/em_rxtx.c
+++ b/lib/librte_pmd_e1000/em_rxtx.c
@@ -1420,10 +1420,10 @@ eth_em_rx_queue_setup(struct rte_eth_dev *dev,
 uint32_t 
 eth_em_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 {
+#define EM_RXQ_SCAN_INTERVAL 4
+	volatile struct e1000_rx_desc *rxdp;
 	struct em_rx_queue *rxq;
-	uint32_t nb_pkts_available;
-	uint32_t rx_rdh;
-	uint32_t rx_id;
+	uint32_t desc = 0;
 
 	if (rx_queue_id >= dev->data->nb_rx_queues) {
 		PMD_RX_LOG(DEBUG,"Invalid RX queue_id=%d\n", rx_queue_id);
@@ -1431,15 +1431,18 @@ eth_em_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	}
 
 	rxq = dev->data->rx_queues[rx_queue_id];
-	rx_id = (uint16_t) ((rxq->rx_tail == 0) ? (rxq->nb_rx_desc - 1) :
-							(rxq->rx_tail - 1));
-	rx_rdh = E1000_PCI_REG(rxq->rdh_reg_addr);
-	if (rx_rdh > rx_id) 
-		nb_pkts_available = rx_rdh - rx_id;
-	else 
-		nb_pkts_available = rx_rdh - rx_id + rxq->nb_rx_desc;
-	
-	return (nb_pkts_available);	
+	rxdp = &(rxq->rx_ring[rxq->rx_tail]);
+
+	while ((desc < rxq->nb_rx_desc) &&
+		(rxdp->status & E1000_RXD_STAT_DD)) {
+		desc += EM_RXQ_SCAN_INTERVAL;
+		rxdp += EM_RXQ_SCAN_INTERVAL;
+		if (rxq->rx_tail + desc >= rxq->nb_rx_desc)
+			rxdp = &(rxq->rx_ring[rxq->rx_tail +
+				desc - rxq->nb_rx_desc]);
+	}
+
+	return desc;
 }
 
 void
diff --git a/lib/librte_pmd_e1000/igb_rxtx.c b/lib/librte_pmd_e1000/igb_rxtx.c
index 87fe56f3f4..b816fb59f1 100644
--- a/lib/librte_pmd_e1000/igb_rxtx.c
+++ b/lib/librte_pmd_e1000/igb_rxtx.c
@@ -1391,26 +1391,29 @@ eth_igb_rx_queue_setup(struct rte_eth_dev *dev,
 uint32_t 
 eth_igb_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 {
+#define IGB_RXQ_SCAN_INTERVAL 4
+	volatile union e1000_adv_rx_desc *rxdp;
 	struct igb_rx_queue *rxq;
-	uint32_t nb_pkts_available;
-	uint32_t rx_rdh;
-	uint32_t rx_id;
+	uint32_t desc = 0;
 
 	if (rx_queue_id >= dev->data->nb_rx_queues) {
-		PMD_RX_LOG(DEBUG,"Invalid RX queue_id=%d\n", rx_queue_id);
+		PMD_RX_LOG(ERR, "Invalid RX queue id=%d\n", rx_queue_id);
 		return 0;
 	}
 
 	rxq = dev->data->rx_queues[rx_queue_id];
-	rx_id = (uint16_t) ((rxq->rx_tail == 0) ? (rxq->nb_rx_desc - 1) :
-							(rxq->rx_tail - 1));
-	rx_rdh = E1000_PCI_REG(rxq->rdh_reg_addr);
-	if (rx_rdh > rx_id) 
-		nb_pkts_available = rx_rdh - rx_id;
-	else
-		nb_pkts_available = rx_rdh - rx_id + rxq->nb_rx_desc;
-	
-	return (nb_pkts_available);
+	rxdp = &(rxq->rx_ring[rxq->rx_tail]);
+
+	while ((desc < rxq->nb_rx_desc) &&
+		(rxdp->wb.upper.status_error & E1000_RXD_STAT_DD)) {
+		desc += IGB_RXQ_SCAN_INTERVAL;
+		rxdp += IGB_RXQ_SCAN_INTERVAL;
+		if (rxq->rx_tail + desc >= rxq->nb_rx_desc)
+			rxdp = &(rxq->rx_ring[rxq->rx_tail +
+				desc - rxq->nb_rx_desc]);
+	}
+
+	return 0;
 }
 
 void