DPDK patches and discussions
 help / color / mirror / Atom feed
From: Thierry Herbelot <thierry.herbelot@6wind.com>
To: dev@dpdk.org
Cc: Olivier Matz <olivier.matz@6wind.com>,
	stable@dpdk.org, Thomas Monjalon <thomas@monjalon.net>
Subject: [dpdk-dev] [PATCH 19.11 V2 04/12] net/e1000: fix Tx descriptor status api (em)
Date: Wed,  7 Aug 2019 17:09:13 +0200	[thread overview]
Message-ID: <792a739c6df952d3d132ec0b4ebc7a0e370d0277.1565190405.git.thierry.herbelot@6wind.com> (raw)
In-Reply-To: <cover.1565190405.git.thierry.herbelot@6wind.com>
In-Reply-To: <cover.1565190405.git.thierry.herbelot@6wind.com>

From: Olivier Matz <olivier.matz@6wind.com>

The Tx descriptor status api was not behaving as expected. This API is
used to inspect the content of the descriptors in the Tx ring to
determine the length of the Tx queue.

Since the software advances the tail pointer and the hardware advances
the head pointer, the Tx queue is located before txq->tx_tail in the
ring. Therefore, a call to rte_eth_tx_descriptor_status(..., offset=20)
should inspect the 20th descriptor before the tail, not after.

As before, we still need to take care about only checking descriptors
that have the RS bit.

Additionally, we can avoid an access to the ring if offset is greater or
equal to nb_tx_desc - nb_tx_free.

Fixes: b9082317cab3 ("net/e1000: implement descriptor status API (em)")
Cc: stable@dpdk.org

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 drivers/net/e1000/em_rxtx.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/drivers/net/e1000/em_rxtx.c b/drivers/net/e1000/em_rxtx.c
index 5925e490641b..3061998c7768 100644
--- a/drivers/net/e1000/em_rxtx.c
+++ b/drivers/net/e1000/em_rxtx.c
@@ -152,6 +152,7 @@ struct em_tx_queue {
 	uint64_t               tx_ring_phys_addr; /**< TX ring DMA address. */
 	struct em_tx_entry    *sw_ring; /**< virtual address of SW ring. */
 	volatile uint32_t      *tdt_reg_addr; /**< Address of TDT register. */
+	volatile uint32_t      *tdh_reg_addr; /**< Address of TDH register. */
 	uint16_t               nb_tx_desc;    /**< number of TX descriptors. */
 	uint16_t               tx_tail;  /**< Current value of TDT register. */
 	/**< Start freeing TX buffers if there are less free descriptors than
@@ -1304,6 +1305,7 @@ eth_em_tx_queue_setup(struct rte_eth_dev *dev,
 	txq->port_id = dev->data->port_id;
 
 	txq->tdt_reg_addr = E1000_PCI_REG_ADDR(hw, E1000_TDT(queue_idx));
+	txq->tdh_reg_addr = E1000_PCI_REG_ADDR(hw, E1000_TDH(queue_idx));
 	txq->tx_ring_phys_addr = tz->iova;
 	txq->tx_ring = (struct e1000_data_desc *) tz->addr;
 
@@ -1557,22 +1559,33 @@ eth_em_tx_descriptor_status(void *tx_queue, uint16_t offset)
 {
 	struct em_tx_queue *txq = tx_queue;
 	volatile uint8_t *status;
-	uint32_t desc;
+	int32_t desc, dd;
 
 	if (unlikely(offset >= txq->nb_tx_desc))
 		return -EINVAL;
+	if (offset >= txq->nb_tx_desc - txq->nb_tx_free)
+		return RTE_ETH_TX_DESC_DONE;
 
-	desc = txq->tx_tail + offset;
-	/* go to next desc that has the RS bit */
-	desc = ((desc + txq->tx_rs_thresh - 1) / txq->tx_rs_thresh) *
-		txq->tx_rs_thresh;
-	if (desc >= txq->nb_tx_desc) {
-		desc -= txq->nb_tx_desc;
-		if (desc >= txq->nb_tx_desc)
-			desc -= txq->nb_tx_desc;
+	desc = txq->tx_tail - offset - 1;
+	if (desc < 0)
+		desc += txq->nb_tx_desc;
+
+	/* offset is too small, no other way than reading PCI reg */
+	if (unlikely(offset < txq->tx_rs_thresh)) {
+		int16_t tx_head, queue_size;
+		tx_head = e1000_read_addr(txq->tdh_reg_addr);
+		queue_size = txq->tx_tail - tx_head;
+		if (queue_size < 0)
+			queue_size += txq->nb_tx_desc;
+		return queue_size > offset ? RTE_ETH_TX_DESC_FULL :
+			RTE_ETH_TX_DESC_DONE;
 	}
 
-	status = &txq->tx_ring[desc].upper.fields.status;
+	/* index of the dd bit to look at */
+	dd = (desc / txq->tx_rs_thresh + 1) * txq->tx_rs_thresh - 1;
+	dd = txq->sw_ring[dd].last_id;
+
+	status = &txq->tx_ring[dd].upper.fields.status;
 	if (*status & E1000_TXD_STAT_DD)
 		return RTE_ETH_TX_DESC_DONE;
 
-- 
2.11.0


  parent reply	other threads:[~2019-08-07 15:10 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-07 14:37 [dpdk-dev] [PATCH 19.11 00/12] Miscellaneous fixes Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 01/12] net/ixgbevf: fix stats update after a PF reset Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 02/12] ethdev: fix description of tx descriptor status Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 03/12] net/e1000: fix Tx descriptor status api (igb) Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 04/12] net/e1000: fix Tx descriptor status api (em) Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 05/12] net/ixgbe: fix Tx descriptor status api Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 06/12] net/i40e: " Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 07/12] net/i40e: set speed to undefined for default case in link update Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 08/12] virtio: fix rx stats with vectorized functions Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 09/12] virtio: get all pending rx packets " Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 10/12] drivers/crypto/openssl: use a local copy for the session contexts Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 11/12] drivers/crypto/dpaa_sec: update DPAA iova table in dpaa_mem_vtop Thierry Herbelot
2019-08-07 14:37 ` [dpdk-dev] [PATCH 19.11 12/12] drivers/crypto/octeontx: enable unbinding for the OcteonTx crypto engines Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 00/12] Miscellaneous fixes Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 " Thierry Herbelot
2019-08-08 13:19     ` Thierry Herbelot
2019-08-08 14:34       ` Thomas Monjalon
2019-10-10 13:01         ` David Marchand
2019-10-10 13:12           ` Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 01/12] net/ixgbevf: fix stats update after a PF reset Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 02/12] ethdev: fix description of tx descriptor status Thierry Herbelot
2019-08-08 10:37     ` Andrew Rybchenko
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 03/12] net/e1000: fix Tx descriptor status api (igb) Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 04/12] net/e1000: fix Tx descriptor status api (em) Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 05/12] net/ixgbe: fix Tx descriptor status api Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 06/12] net/i40e: " Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 07/12] net/i40e: set speed to undefined for default case in link update Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 08/12] virtio: fix rx stats with vectorized functions Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 09/12] virtio: get all pending rx packets " Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 10/12] drivers/crypto/openssl: use a local copy for the session contexts Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 11/12] drivers/crypto/dpaa_sec: update DPAA iova table in dpaa_mem_vtop Thierry Herbelot
2019-08-08  8:22   ` [dpdk-dev] [PATCH 19.11 V3 12/12] drivers/crypto/octeontx: enable unbinding for the OcteonTx crypto engines Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 01/12] net/ixgbevf: fix stats update after a PF reset Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 02/12] ethdev: fix description of tx descriptor status Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 03/12] net/e1000: fix Tx descriptor status api (igb) Thierry Herbelot
2019-08-07 15:09 ` Thierry Herbelot [this message]
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 05/12] net/ixgbe: fix Tx descriptor status api Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 06/12] net/i40e: " Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 07/12] net/i40e: set speed to undefined for default case in link update Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 08/12] virtio: fix rx stats with vectorized functions Thierry Herbelot
2019-08-08  5:15   ` [dpdk-dev] [dpdk-stable] " Tiwei Bie
2019-08-08  7:35     ` Thibaut Collet
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 09/12] virtio: get all pending rx packets " Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 10/12] drivers/crypto/openssl: use a local copy for the session contexts Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 11/12] drivers/crypto/dpaa_sec: update DPAA iova table in dpaa_mem_vtop Thierry Herbelot
2019-08-07 15:09 ` [dpdk-dev] [PATCH 19.11 V2 12/12] drivers/crypto/octeontx: enable unbinding for the OcteonTx crypto engines Thierry Herbelot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=792a739c6df952d3d132ec0b4ebc7a0e370d0277.1565190405.git.thierry.herbelot@6wind.com \
    --to=thierry.herbelot@6wind.com \
    --cc=dev@dpdk.org \
    --cc=olivier.matz@6wind.com \
    --cc=stable@dpdk.org \
    --cc=thomas@monjalon.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).