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From: Olivier Matz <olivier.matz@6wind.com>
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Date: Thu, 24 Nov 2016 10:54:21 +0100
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Subject: [dpdk-dev] [RFC 9/9] net/e1000: add handler for tx queue descriptor
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Like for TX, use a binary search algorithm to get the number of used Tx
descriptors.
PR=52423
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Ivan Boule <ivan.boule@6wind.com>
---
drivers/net/e1000/e1000_ethdev.h | 5 +++-
drivers/net/e1000/em_ethdev.c | 1 +
drivers/net/e1000/em_rxtx.c | 51 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 56 insertions(+), 1 deletion(-)
diff --git a/drivers/net/e1000/e1000_ethdev.h b/drivers/net/e1000/e1000_ethdev.h
index ad9ddaf..8945916 100644
--- a/drivers/net/e1000/e1000_ethdev.h
+++ b/drivers/net/e1000/e1000_ethdev.h
@@ -364,7 +364,10 @@ int eth_em_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
struct rte_mempool *mb_pool);
uint32_t eth_em_rx_queue_count(struct rte_eth_dev *dev,
- uint16_t rx_queue_id);
+ uint16_t rx_queue_id);
+
+uint32_t eth_em_tx_queue_count(struct rte_eth_dev *dev,
+ uint16_t tx_queue_id);
int eth_em_rx_descriptor_done(void *rx_queue, uint16_t offset);
diff --git a/drivers/net/e1000/em_ethdev.c b/drivers/net/e1000/em_ethdev.c
index 866a5cf..7fe5e3b 100644
--- a/drivers/net/e1000/em_ethdev.c
+++ b/drivers/net/e1000/em_ethdev.c
@@ -190,6 +190,7 @@ static const struct eth_dev_ops eth_em_ops = {
.rx_queue_setup = eth_em_rx_queue_setup,
.rx_queue_release = eth_em_rx_queue_release,
.rx_queue_count = eth_em_rx_queue_count,
+ .tx_queue_count = eth_em_tx_queue_count,
.rx_descriptor_done = eth_em_rx_descriptor_done,
.tx_queue_setup = eth_em_tx_queue_setup,
.tx_queue_release = eth_em_tx_queue_release,
diff --git a/drivers/net/e1000/em_rxtx.c b/drivers/net/e1000/em_rxtx.c
index a469fd7..8afcfda 100644
--- a/drivers/net/e1000/em_rxtx.c
+++ b/drivers/net/e1000/em_rxtx.c
@@ -1432,6 +1432,57 @@ eth_em_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id)
return offset;
}
+uint32_t
+eth_em_tx_queue_count(struct rte_eth_dev *dev, uint16_t tx_queue_id)
+{
+ volatile uint8_t *status;
+ struct em_tx_queue *txq;
+ int32_t offset, interval, idx, resolution;
+
+ txq = dev->data->tx_queues[tx_queue_id];
+
+ /* check if ring empty */
+ idx = txq->tx_tail - 1;
+ if (idx < 0)
+ idx += txq->nb_tx_desc;
+ status = &txq->tx_ring[idx].upper.fields.status;
+ if (*status & E1000_TXD_STAT_DD)
+ return 0;
+
+ /* check if ring full */
+ idx = txq->tx_tail + 1;
+ if (idx >= txq->nb_tx_desc)
+ idx -= txq->nb_tx_desc;
+ status = &txq->tx_ring[idx].upper.fields.status;
+ if (!(*status & E1000_TXD_STAT_DD))
+ return txq->nb_tx_desc;
+
+ /* decrease the precision if ring is large */
+ if (txq->nb_tx_desc <= 256)
+ resolution = 4;
+ else
+ resolution = 16;
+
+ /* use a binary search */
+ offset = txq->nb_tx_desc >> 1;
+ interval = offset;
+
+ do {
+ idx = txq->tx_tail + offset;
+ if (idx >= txq->nb_tx_desc)
+ idx -= txq->nb_tx_desc;
+
+ interval >>= 1;
+ status = &txq->tx_ring[idx].upper.fields.status;
+ if (*status & E1000_TXD_STAT_DD)
+ offset += interval;
+ else
+ offset -= interval;
+ } while (interval >= resolution);
+
+ return txq->nb_tx_desc - offset;
+}
+
int
eth_em_rx_descriptor_done(void *rx_queue, uint16_t offset)
{
--
2.8.1