diff options
Diffstat (limited to 'target/linux/layerscape/patches-5.4/701-net-0047-sdk_dpaa-update-comments-about-recycling-and-back-po.patch')
| -rw-r--r-- | target/linux/layerscape/patches-5.4/701-net-0047-sdk_dpaa-update-comments-about-recycling-and-back-po.patch | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/701-net-0047-sdk_dpaa-update-comments-about-recycling-and-back-po.patch b/target/linux/layerscape/patches-5.4/701-net-0047-sdk_dpaa-update-comments-about-recycling-and-back-po.patch new file mode 100644 index 0000000000..a54dce9f28 --- /dev/null +++ b/target/linux/layerscape/patches-5.4/701-net-0047-sdk_dpaa-update-comments-about-recycling-and-back-po.patch @@ -0,0 +1,67 @@ +From 2d7b6e7daf076b63f461ce9c4ec6022ddc3d15bb Mon Sep 17 00:00:00 2001 +From: Camelia Groza <camelia.groza@nxp.com> +Date: Mon, 15 Jan 2018 17:42:42 +0200 +Subject: [PATCH] sdk_dpaa: update comments about recycling and back-pointer + storage + +Signed-off-by: Camelia Groza <camelia.groza@nxp.com> +--- + drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 18 ++++++++++++++++-- + 1 file changed, 16 insertions(+), 2 deletions(-) + +--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c ++++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c +@@ -121,6 +121,10 @@ static int _dpa_bp_add_8_bufs(const stru + put_page(virt_to_head_page(new_buf)); + goto build_skb_failed; + } ++ ++ /* Store the skb back-pointer before the start of the buffer. ++ * Otherwise it will be overwritten by the FMan. ++ */ + DPA_WRITE_SKB_PTR(skb, skbh, new_buf, -1); + + addr = dma_map_single(dev, new_buf, +@@ -344,7 +348,10 @@ bool dpa_buf_is_recyclable(struct sk_buf + * - buffer address aligned to cacheline bytes + * - offset of data from start of buffer no lower than a minimum value + * - offset of data from start of buffer no higher than a maximum value ++ * - the skb back-pointer is stored safely + */ ++ ++ /* guarantee both the minimum size and the minimum data offset */ + new = min(skb_end_pointer(skb) - min_size, skb->data - min_offset); + + /* left align to the nearest cacheline */ +@@ -694,6 +701,9 @@ int __hot skb_to_contig_fd(struct dpa_pr + dma_dir = DMA_BIDIRECTIONAL; + dma_map_size = dpa_bp->size; + ++ /* Store the skb back-pointer before the start of the buffer. ++ * Otherwise it will be overwritten by the FMan. ++ */ + DPA_WRITE_SKB_PTR(skb, skbh, buffer_start, -1); + *offset = skb_headroom(skb) - fd->offset; + } else +@@ -711,7 +721,7 @@ int __hot skb_to_contig_fd(struct dpa_pr + + /* The buffer will be Tx-confirmed, but the TxConf cb must + * necessarily look at our Tx private data to retrieve the +- * skbuff. (In short: can't use DPA_WRITE_SKB_PTR() here.) ++ * skbuff. Store the back-pointer inside the buffer. + */ + DPA_WRITE_SKB_PTR(skb, skbh, buffer_start, 0); + } +@@ -975,7 +985,11 @@ int __hot skb_to_sg_fd(struct dpa_priv_s + fd->length20 = skb->len; + fd->offset = priv->tx_headroom; + +- /* DMA map the SGT page */ ++ /* DMA map the SGT page ++ * ++ * It's safe to store the skb back-pointer inside the buffer since ++ * S/G frames are non-recyclable. ++ */ + DPA_WRITE_SKB_PTR(skb, skbh, sgt_buf, 0); + addr = dma_map_single(dpa_bp->dev, sgt_buf, + priv->tx_headroom + sgt_size, |