Message ID | 20200110115415.75683-7-andre.przywara@arm.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | net: axienet: Error handling, SGMII and 64-bit DMA fixes | expand |
> -----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
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)) { + dev_kfree_skb(skb); + 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; + 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;
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(-)