From: Radhey Shyam Pandey <radheys@xilinx.com>
To: Andre Przywara <andre.przywara@arm.com>,
"David S . Miller" <davem@davemloft.net>
Cc: Michal Simek <michals@xilinx.com>,
Robert Hancock <hancock@sedsystems.ca>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 06/14] net: axienet: Check for DMA mapping errors
Date: Mon, 13 Jan 2020 05:54:42 +0000 [thread overview]
Message-ID: <CH2PR02MB70001247E6EE3EF6968CCC04C7350@CH2PR02MB7000.namprd02.prod.outlook.com> (raw)
In-Reply-To: <20200110115415.75683-7-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 06/14] net: axienet: Check for DMA mapping errors
>
> Especially with the default 32-bit DMA mask, DMA buffers are a limited
> resource, so their allocation can fail.
> So as the DMA API documentation requires, add error checking code after
> dma_map_single() calls to catch the case where we run out of "low" memory.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> .../net/ethernet/xilinx/xilinx_axienet_main.c | 22 ++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> index 82abe2b0f16a..8d2b67cbecf9 100644
> --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
> @@ -248,6 +248,11 @@ static int axienet_dma_bd_init(struct net_device
> *ndev)
> skb->data,
> lp->max_frm_size,
> DMA_FROM_DEVICE);
> + if (dma_mapping_error(ndev->dev.parent, lp->rx_bd_v[i].phys))
Prefer using unlikely compiler hint for dma_mapping_error.
Also, we need to add error print to report this condition to the user,
in case it isn't there in dma_mapping_error implementation.
> {
> + dev_kfree_skb(skb);
free of skb is already handled in _release. We can reuse that?
> + goto out;
> + }
> +
> lp->rx_bd_v[i].cntrl = lp->max_frm_size;
> }
>
> @@ -668,6 +673,7 @@ axienet_start_xmit(struct sk_buff *skb, struct
> net_device *ndev)
> dma_addr_t tail_p;
> struct axienet_local *lp = netdev_priv(ndev);
> struct axidma_bd *cur_p;
> + u32 orig_tail_ptr = lp->tx_bd_tail;
>
> num_frag = skb_shinfo(skb)->nr_frags;
> cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
> @@ -703,9 +709,11 @@ axienet_start_xmit(struct sk_buff *skb, struct
> net_device *ndev)
> cur_p->app0 |= 2; /* Tx Full Checksum Offload Enabled */
> }
>
> - cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;
> cur_p->phys = dma_map_single(ndev->dev.parent, skb->data,
> skb_headlen(skb), DMA_TO_DEVICE);
> + if (dma_mapping_error(ndev->dev.parent, cur_p->phys))
> + return NETDEV_TX_BUSY;
This is not ideally tx busy and related to available mem mapping in the system.
I just looked at other eth drivers and it seems they return TX_OK with drop
count stats incremented.
> + cur_p->cntrl = skb_headlen(skb) | XAXIDMA_BD_CTRL_TXSOF_MASK;
>
> for (ii = 0; ii < num_frag; ii++) {
> if (++lp->tx_bd_tail >= lp->tx_bd_num) @@ -716,6 +724,13 @@
> axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
> skb_frag_address(frag),
> skb_frag_size(frag),
> DMA_TO_DEVICE);
> + if (dma_mapping_error(ndev->dev.parent, cur_p->phys)) {
> + axienet_free_tx_chain(ndev, orig_tail_ptr, ii + 1,
> + NULL);
> + lp->tx_bd_tail = orig_tail_ptr;
> +
> + return NETDEV_TX_BUSY;
> + }
> cur_p->cntrl = skb_frag_size(frag);
> }
>
> @@ -796,6 +811,11 @@ static void axienet_recv(struct net_device *ndev)
> cur_p->phys = dma_map_single(ndev->dev.parent, new_skb-
> >data,
> lp->max_frm_size,
> DMA_FROM_DEVICE);
> + if (dma_mapping_error(ndev->dev.parent, cur_p->phys)) {
> + dev_kfree_skb(new_skb);
> + return;
> + }
> +
> cur_p->cntrl = lp->max_frm_size;
> cur_p->status = 0;
> cur_p->skb = new_skb;
> --
> 2.17.1
next prev parent reply other threads:[~2020-01-13 5:54 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
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 [this message]
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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