From: Andre Przywara <andre.przywara@arm.com>
To: "David S . Miller" <davem@davemloft.net>,
Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Cc: Robert Hancock <hancock@sedsystems.ca>,
netdev@vger.kernel.org, Michal Simek <michal.simek@xilinx.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 05/14] net: axienet: Factor out TX descriptor chain cleanup
Date: Fri, 10 Jan 2020 11:54:06 +0000 [thread overview]
Message-ID: <20200110115415.75683-6-andre.przywara@arm.com> (raw)
In-Reply-To: <20200110115415.75683-1-andre.przywara@arm.com>
Factor out the code that cleans up a number of connected TX descriptors,
as we will need it to properly roll back a failed _xmit() call.
There are subtle differences between cleaning up a successfully sent
chain (unknown number of involved descriptors, total data size needed)
and a chain that was about to set up (number of descriptors known), so
cater for those variations with some extra parameters.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
.../net/ethernet/xilinx/xilinx_axienet_main.c | 75 ++++++++++++-------
1 file changed, 50 insertions(+), 25 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index ec5d01adc1d5..82abe2b0f16a 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -543,33 +543,37 @@ static int axienet_device_reset(struct net_device *ndev)
return 0;
}
-/**
- * axienet_start_xmit_done - Invoked once a transmit is completed by the
- * Axi DMA Tx channel.
- * @ndev: Pointer to the net_device structure
- *
- * This function is invoked from the Axi DMA Tx isr to notify the completion
- * of transmit operation. It clears fields in the corresponding Tx BDs and
- * unmaps the corresponding buffer so that CPU can regain ownership of the
- * buffer. It finally invokes "netif_wake_queue" to restart transmission if
- * required.
+/* Clean up a series of linked TX descriptors. Would either be called
+ * after a successful transmit operation, or after there was an error
+ * when setting up the chain.
+ * Returns the number of descriptors handled.
*/
-static void axienet_start_xmit_done(struct net_device *ndev)
+static int axienet_free_tx_chain(struct net_device *ndev, u32 first_bd,
+ int nr_bds, u32 *sizep)
{
- u32 size = 0;
- u32 packets = 0;
struct axienet_local *lp = netdev_priv(ndev);
+ int max_bds = (nr_bds != -1) ? nr_bds : lp->tx_bd_num;
struct axidma_bd *cur_p;
- unsigned int status = 0;
+ unsigned int status;
+ int i;
+
+ for (i = 0; i < max_bds; i++) {
+ cur_p = &lp->tx_bd_v[(first_bd + i) % lp->tx_bd_num];
+ status = cur_p->status;
+
+ /* If no number is given, clean up *all* descriptors that have
+ * been completed by the MAC.
+ */
+ if (nr_bds == -1 && !(status & XAXIDMA_BD_STS_COMPLETE_MASK))
+ break;
- cur_p = &lp->tx_bd_v[lp->tx_bd_ci];
- status = cur_p->status;
- while (status & XAXIDMA_BD_STS_COMPLETE_MASK) {
dma_unmap_single(ndev->dev.parent, cur_p->phys,
(cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK),
DMA_TO_DEVICE);
- if (cur_p->skb)
+
+ if (cur_p->skb && (status & XAXIDMA_BD_STS_COMPLETE_MASK))
dev_consume_skb_irq(cur_p->skb);
+
cur_p->cntrl = 0;
cur_p->app0 = 0;
cur_p->app1 = 0;
@@ -578,15 +582,36 @@ static void axienet_start_xmit_done(struct net_device *ndev)
cur_p->status = 0;
cur_p->skb = NULL;
- size += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
- packets++;
-
- if (++lp->tx_bd_ci >= lp->tx_bd_num)
- lp->tx_bd_ci = 0;
- cur_p = &lp->tx_bd_v[lp->tx_bd_ci];
- status = cur_p->status;
+ if (sizep)
+ *sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK;
}
+ return i;
+}
+
+/**
+ * axienet_start_xmit_done - Invoked once a transmit is completed by the
+ * Axi DMA Tx channel.
+ * @ndev: Pointer to the net_device structure
+ *
+ * This function is invoked from the Axi DMA Tx isr to notify the completion
+ * of transmit operation. It clears fields in the corresponding Tx BDs and
+ * unmaps the corresponding buffer so that CPU can regain ownership of the
+ * buffer. It finally invokes "netif_wake_queue" to restart transmission if
+ * required.
+ */
+static void axienet_start_xmit_done(struct net_device *ndev)
+{
+ u32 size = 0;
+ u32 packets = 0;
+ struct axienet_local *lp = netdev_priv(ndev);
+
+ packets = axienet_free_tx_chain(ndev, lp->tx_bd_ci, -1, &size);
+
+ lp->tx_bd_ci += packets;
+ if (lp->tx_bd_ci >= lp->tx_bd_num)
+ lp->tx_bd_ci -= lp->tx_bd_num;
+
ndev->stats.tx_packets += packets;
ndev->stats.tx_bytes += size;
--
2.17.1
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next prev parent reply other threads:[~2020-01-10 11:56 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 11:54 [PATCH 00/14] net: axienet: Error handling, SGMII and 64-bit DMA fixes Andre Przywara
2020-01-10 11:54 ` [PATCH 01/14] net: xilinx: temac: Relax Kconfig dependencies Andre Przywara
2020-01-10 14:19 ` Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 02/14] net: axienet: Propagate failure of DMA descriptor setup Andre Przywara
2020-01-10 14:54 ` Radhey Shyam Pandey
2020-01-10 17:53 ` Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 03/14] net: axienet: Fix DMA descriptor cleanup path Andre Przywara
2020-01-10 15:14 ` Radhey Shyam Pandey
2020-01-10 15:43 ` Andre Przywara
2020-01-10 17:05 ` Radhey Shyam Pandey
2020-01-16 18:03 ` Andre Przywara
2020-01-20 18:32 ` Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 04/14] net: axienet: Improve DMA error handling Andre Przywara
2020-01-10 15:26 ` Radhey Shyam Pandey
2020-01-10 11:54 ` Andre Przywara [this message]
2020-01-10 18:04 ` [PATCH 05/14] net: axienet: Factor out TX descriptor chain cleanup Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 06/14] net: axienet: Check for DMA mapping errors Andre Przywara
2020-01-13 5:54 ` Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 07/14] net: axienet: Fix SGMII support Andre Przywara
2020-01-10 14:04 ` Andrew Lunn
2020-01-10 14:20 ` Andre Przywara
2020-01-10 14:26 ` Andrew Lunn
2020-01-10 15:04 ` Russell King - ARM Linux admin
2020-01-10 15:22 ` Russell King - ARM Linux admin
2020-01-10 17:04 ` Russell King - ARM Linux admin
2020-01-18 11:22 ` Russell King - ARM Linux admin
2020-01-20 14:50 ` Andre Przywara
2020-01-20 15:45 ` Russell King - ARM Linux admin
2020-01-27 17:04 ` Andre Przywara
2020-01-27 17:20 ` Radhey Shyam Pandey
2020-01-27 18:53 ` Russell King - ARM Linux admin
2020-04-22 1:45 ` Xilinx axienet 1000BaseX support (was: Re: [PATCH 07/14] net: axienet: Fix SGMII support) Robert Hancock
2020-04-22 7:51 ` Russell King - ARM Linux admin
2020-04-22 16:31 ` Xilinx axienet 1000BaseX support Robert Hancock
2020-04-28 21:59 ` Robert Hancock
2020-04-28 23:01 ` Russell King - ARM Linux admin
2020-04-28 23:51 ` Robert Hancock
2020-04-29 8:21 ` Russell King - ARM Linux admin
2020-01-10 14:58 ` [PATCH 07/14] net: axienet: Fix SGMII support Russell King - ARM Linux admin
2020-01-10 17:32 ` Andre Przywara
2020-01-10 18:05 ` Russell King - ARM Linux admin
2020-01-10 19:33 ` Andrew Lunn
2020-01-10 11:54 ` [PATCH 08/14] net: axienet: Drop MDIO interrupt registers from ethtools dump Andre Przywara
2020-01-13 6:02 ` Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 09/14] net: axienet: Add mii-tool support Andre Przywara
2020-01-13 6:12 ` Radhey Shyam Pandey
2020-03-12 11:41 ` Andre Przywara
2020-01-10 11:54 ` [PATCH 10/14] net: axienet: Wrap DMA pointer writes to prepare for 64 bit Andre Przywara
2020-01-10 11:54 ` [PATCH 11/14] net: axienet: Upgrade descriptors to hold 64-bit addresses Andre Przywara
2020-01-14 16:35 ` Radhey Shyam Pandey
2020-01-14 17:29 ` Andre Przywara
2020-01-10 11:54 ` [PATCH 12/14] net: axienet: Autodetect 64-bit DMA capability Andre Przywara
2020-01-10 14:08 ` Andrew Lunn
2020-01-10 14:13 ` Andre Przywara
2020-01-10 14:22 ` Andrew Lunn
2020-01-10 15:08 ` Andre Przywara
2020-01-10 15:22 ` Andrew Lunn
2020-01-14 17:03 ` Radhey Shyam Pandey
2020-01-14 17:41 ` Andre Przywara
2020-01-15 6:02 ` Radhey Shyam Pandey
2020-01-10 11:54 ` [PATCH 13/14] net: axienet: Allow DMA to beyond 4GB Andre Przywara
2020-01-10 11:54 ` [PATCH 14/14] net: axienet: Update devicetree binding documentation Andre Przywara
2020-01-21 21:51 ` Rob Herring
2020-01-24 16:29 ` Andre Przywara
2020-01-27 9:28 ` Radhey Shyam Pandey
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