From: Yuusuke Ashiduka <ashid...@jp.fujitsu.com> Sent: Tuesday, January 17,
2017 3:48 PM
>To: Andy Duan <fugang.d...@nxp.com>
>Cc: netdev@vger.kernel.org; Yuusuke Ashiduka <ashid...@jp.fujitsu.com>
>Subject: [PATCH] net: fec: Fixed panic problem with non-tso
>
>If highmem and 2GB or more of memory are valid, "this_frag-> page.p"
>indicates the highmem area, so the result of page_address() is NULL and panic
>occurs.
>
>This commit fixes this by using the skb_frag_dma_map() helper, which takes
>care of mapping the skb fragment properly. Additionally, the type of mapping
>is now tracked, so it can be unmapped using dma_unmap_page or
>dma_unmap_single when appropriate.
>---
> drivers/net/ethernet/freescale/fec.h | 1 +
> drivers/net/ethernet/freescale/fec_main.c | 48
>+++++++++++++++++++++++--------
> 2 files changed, 37 insertions(+), 12 deletions(-)
>
The patch itself seems fine.
The driver doesn't support skb from highmem, if to support highmem, it should
add frag_skb (highmem) support for tso and non-tso.
In driver net/core/tso.c, it also add highmem support, right ?
Thanks.
>diff --git a/drivers/net/ethernet/freescale/fec.h
>b/drivers/net/ethernet/freescale/fec.h
>index 5ea740b4cf14..5b187e8aacf0 100644
>--- a/drivers/net/ethernet/freescale/fec.h
>+++ b/drivers/net/ethernet/freescale/fec.h
>@@ -463,6 +463,7 @@ struct bufdesc_prop { struct fec_enet_priv_tx_q {
> struct bufdesc_prop bd;
> unsigned char *tx_bounce[TX_RING_SIZE];
>+ int tx_page_mapping[TX_RING_SIZE];
> struct sk_buff *tx_skbuff[TX_RING_SIZE];
>
> unsigned short tx_stop_threshold;
>diff --git a/drivers/net/ethernet/freescale/fec_main.c
>b/drivers/net/ethernet/freescale/fec_main.c
>index 38160c2bebcb..b1562107e337 100644
>--- a/drivers/net/ethernet/freescale/fec_main.c
>+++ b/drivers/net/ethernet/freescale/fec_main.c
>@@ -60,6 +60,7 @@
> #include <linux/if_vlan.h>
> #include <linux/pinctrl/consumer.h>
> #include <linux/prefetch.h>
>+#include <linux/highmem.h>
> #include <soc/imx/cpuidle.h>
>
> #include <asm/cacheflush.h>
>@@ -377,20 +378,28 @@ fec_enet_txq_submit_frag_skb(struct
>fec_enet_priv_tx_q *txq,
> ebdp->cbd_esc = cpu_to_fec32(estatus);
> }
>
>- bufaddr = page_address(this_frag->page.p) + this_frag-
>>page_offset;
>-
> index = fec_enet_get_bd_index(bdp, &txq->bd);
>- if (((unsigned long) bufaddr) & fep->tx_align ||
>+ txq->tx_page_mapping[index] = 0;
>+ if (this_frag->page_offset & fep->tx_align ||
> fep->quirks & FEC_QUIRK_SWAP_FRAME) {
>+ bufaddr = kmap_atomic(this_frag->page.p) +
>+ this_frag->page_offset;
> memcpy(txq->tx_bounce[index], bufaddr, frag_len);
>+ kunmap_atomic(bufaddr);
> bufaddr = txq->tx_bounce[index];
>
> if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
> swap_buffer(bufaddr, frag_len);
>+ addr = dma_map_single(&fep->pdev->dev,
>+ bufaddr,
>+ frag_len,
>+ DMA_TO_DEVICE);
>+ } else {
>+ txq->tx_page_mapping[index] = 1;
>+ addr = skb_frag_dma_map(&fep->pdev->dev,
>this_frag, 0,
>+ frag_len, DMA_TO_DEVICE);
> }
>
>- addr = dma_map_single(&fep->pdev->dev, bufaddr, frag_len,
>- DMA_TO_DEVICE);
> if (dma_mapping_error(&fep->pdev->dev, addr)) {
> if (net_ratelimit())
> netdev_err(ndev, "Tx DMA memory map
>failed\n"); @@ -411,8 +420,16 @@ fec_enet_txq_submit_frag_skb(struct
>fec_enet_priv_tx_q *txq,
> bdp = txq->bd.cur;
> for (i = 0; i < frag; i++) {
> bdp = fec_enet_get_nextdesc(bdp, &txq->bd);
>- dma_unmap_single(&fep->pdev->dev, fec32_to_cpu(bdp-
>>cbd_bufaddr),
>- fec16_to_cpu(bdp->cbd_datlen),
>DMA_TO_DEVICE);
>+ if (txq->tx_page_mapping[index])
>+ dma_unmap_page(&fep->pdev->dev,
>+ fec32_to_cpu(bdp->cbd_bufaddr),
>+ fec16_to_cpu(bdp->cbd_datlen),
>+ DMA_TO_DEVICE);
>+ else
>+ dma_unmap_single(&fep->pdev->dev,
>+ fec32_to_cpu(bdp->cbd_bufaddr),
>+ fec16_to_cpu(bdp->cbd_datlen),
>+ DMA_TO_DEVICE);
> }
> return ERR_PTR(-ENOMEM);
> }
>@@ -1201,11 +1218,18 @@ fec_enet_tx_queue(struct net_device *ndev, u16
>queue_id)
>
> skb = txq->tx_skbuff[index];
> txq->tx_skbuff[index] = NULL;
>- if (!IS_TSO_HEADER(txq, fec32_to_cpu(bdp->cbd_bufaddr)))
>- dma_unmap_single(&fep->pdev->dev,
>- fec32_to_cpu(bdp->cbd_bufaddr),
>- fec16_to_cpu(bdp->cbd_datlen),
>- DMA_TO_DEVICE);
>+ if (!IS_TSO_HEADER(txq, fec32_to_cpu(bdp->cbd_bufaddr)))
>{
>+ if (txq->tx_page_mapping[index])
>+ dma_unmap_page(&fep->pdev->dev,
>+ fec32_to_cpu(bdp->cbd_bufaddr),
>+ fec16_to_cpu(bdp->cbd_datlen),
>+ DMA_TO_DEVICE);
>+ else
>+ dma_unmap_single(&fep->pdev->dev,
>+ fec32_to_cpu(bdp-
>>cbd_bufaddr),
>+ fec16_to_cpu(bdp-
>>cbd_datlen),
>+ DMA_TO_DEVICE);
>+ }
> bdp->cbd_bufaddr = cpu_to_fec32(0);
> if (!skb)
> goto skb_done;
>--
>2.11.0
