diff options
Diffstat (limited to 'target/linux/layerscape/patches-5.4/701-net-0080-sdk_dpaa-store-the-skb-backpointer-in-the-skb-headro.patch')
| -rw-r--r-- | target/linux/layerscape/patches-5.4/701-net-0080-sdk_dpaa-store-the-skb-backpointer-in-the-skb-headro.patch | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/target/linux/layerscape/patches-5.4/701-net-0080-sdk_dpaa-store-the-skb-backpointer-in-the-skb-headro.patch b/target/linux/layerscape/patches-5.4/701-net-0080-sdk_dpaa-store-the-skb-backpointer-in-the-skb-headro.patch new file mode 100644 index 0000000000..12e5d15795 --- /dev/null +++ b/target/linux/layerscape/patches-5.4/701-net-0080-sdk_dpaa-store-the-skb-backpointer-in-the-skb-headro.patch @@ -0,0 +1,84 @@ +From 1f00fa355829b510beb900ce1136f40802e6076e Mon Sep 17 00:00:00 2001 +From: Camelia Groza <camelia.groza@nxp.com> +Date: Mon, 10 Sep 2018 14:31:05 +0300 +Subject: [PATCH] sdk_dpaa: store the skb backpointer in the skb headroom + +The skb backpointer is stored right before the FMan buffer, in order to +avoid overwriting. The memory area storing the backpointer was outside of +the skb. This made it hard to guarantee its size. + +This patch changes the layout of the skb at buffer seed time: the area +reserved for storing the skb backpointer is part of the skb's headroom. +This makes it easier to track if the backpointer can be safely stored +when recycling the buffer. + +Signed-off-by: Camelia Groza <camelia.groza@nxp.com> +--- + .../net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c | 33 ++++++++++++++++------ + 1 file changed, 24 insertions(+), 9 deletions(-) + +--- a/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c ++++ b/drivers/net/ethernet/freescale/sdk_dpaa/dpaa_eth_sg.c +@@ -82,8 +82,8 @@ static void dpa_bp_recycle_frag(struct d + + static int _dpa_bp_add_8_bufs(const struct dpa_bp *dpa_bp) + { ++ void *new_buf, *fman_buf; + struct bm_buffer bmb[8]; +- void *new_buf; + dma_addr_t addr; + uint8_t i; + struct device *dev = dpa_bp->dev; +@@ -113,21 +113,37 @@ static int _dpa_bp_add_8_bufs(const stru + + if (unlikely(!new_buf)) + goto netdev_alloc_failed; +- new_buf = PTR_ALIGN(new_buf + SMP_CACHE_BYTES, SMP_CACHE_BYTES); ++ new_buf = PTR_ALIGN(new_buf, SMP_CACHE_BYTES); + +- skb = build_skb(new_buf, DPA_SKB_SIZE(dpa_bp->size) + +- SKB_DATA_ALIGN(sizeof(struct skb_shared_info))); ++ /* Apart from the buffer that will be used by the FMan, the ++ * skb also guarantees enough space to hold the backpointer ++ * in the headroom and the shared info at the end. ++ */ ++ skb = build_skb(new_buf, ++ SMP_CACHE_BYTES + DPA_SKB_SIZE(dpa_bp->size) + ++ SKB_DATA_ALIGN(sizeof(struct skb_shared_info))); + if (unlikely(!skb)) { + 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. ++ /* Reserve SMP_CACHE_BYTES in the skb's headroom to store the ++ * backpointer. This area will not be synced to, or ++ * overwritten by, the FMan. ++ */ ++ skb_reserve(skb, SMP_CACHE_BYTES); ++ ++ /* We don't sync the first SMP_CACHE_BYTES of the buffer to ++ * the FMan. The skb backpointer is stored at the end of the ++ * reserved headroom. Otherwise it will be overwritten by the ++ * FMan. ++ * The buffer synced with the FMan starts right after the ++ * reserved headroom. + */ +- DPA_WRITE_SKB_PTR(skb, skbh, new_buf, -1); ++ fman_buf = new_buf + SMP_CACHE_BYTES; ++ DPA_WRITE_SKB_PTR(skb, skbh, fman_buf, -1); + +- addr = dma_map_single(dev, new_buf, ++ addr = dma_map_single(dev, fman_buf, + dpa_bp->size, DMA_BIDIRECTIONAL); + if (unlikely(dma_mapping_error(dev, addr))) + goto dma_map_failed; +@@ -477,7 +493,6 @@ static struct sk_buff *__hot sg_fd_to_sk + DMA_BIDIRECTIONAL); + if (i == 0) { + DPA_READ_SKB_PTR(skb, skbh, sg_vaddr, -1); +- DPA_BUG_ON(skb->head != sg_vaddr); + #ifdef CONFIG_FSL_DPAA_1588 + if (priv->tsu && priv->tsu->valid && + priv->tsu->hwts_rx_en_ioctl) |