From: Radhey Shyam Pandey <radheys@xilinx.com>
To: Andre Przywara <andre.przywara@arm.com>,
"David S . Miller" <davem@davemloft.net>
Cc: Robert Hancock <hancock@sedsystems.ca>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Michal Simek <michals@xilinx.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: RE: [PATCH 05/14] net: axienet: Factor out TX descriptor chain cleanup
Date: Fri, 10 Jan 2020 18:04:57 +0000 [thread overview]
Message-ID: <CH2PR02MB70003A0D500B9A78697FC311C7380@CH2PR02MB7000.namprd02.prod.outlook.com> (raw)
In-Reply-To: <20200110115415.75683-6-andre.przywara@arm.com>
> -----Original Message-----
> From: Andre Przywara <andre.przywara@arm.com>
> Sent: Friday, January 10, 2020 5:24 PM
> To: David S . Miller <davem@davemloft.net>; Radhey Shyam Pandey
> <radheys@xilinx.com>
> Cc: Michal Simek <michals@xilinx.com>; Robert Hancock
> <hancock@sedsystems.ca>; netdev@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org
> Subject: [PATCH 05/14] net: axienet: Factor out TX descriptor chain cleanup
>
> 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)
To be consistent we can add the doxygen function description.
The rest looks good. Feel free to add:
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
> +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 18:05 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 ` [PATCH 05/14] net: axienet: Factor out TX descriptor chain cleanup Andre Przywara
2020-01-10 18:04 ` Radhey Shyam Pandey [this message]
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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