[PATCH net-next 1/4] dpaa_eth: fix SG mapping
From: Madalin Bucur <madalin.bucur@nxp.com>
Date: 2018-02-19 16:11:18
Also in:
lkml
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
An issue in the code mapping the skb fragments into scatter-gather frames was evidentiated by netperf TCP_SENDFILE tests. This patch addresses the issue. Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com> --- drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 27 ++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index a998c36..a5afa60 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c@@ -1889,7 +1889,7 @@ static int skb_to_sg_fd(struct dpaa_priv *priv, void *buffer_start; skb_frag_t *frag; dma_addr_t addr; - size_t frag_len; + size_t buff_len; void *sgt_buf; /* get a page frag to store the SGTable */
@@ -1916,8 +1916,10 @@ static int skb_to_sg_fd(struct dpaa_priv *priv, goto csum_failed; } + /* SGT[0] is used by the linear part */ sgt = (struct qm_sg_entry *)(sgt_buf + priv->tx_headroom); - qm_sg_entry_set_len(&sgt[0], skb_headlen(skb)); + buff_len = skb_headlen(skb); + qm_sg_entry_set_len(&sgt[0], buff_len); sgt[0].bpid = FSL_DPAA_BPID_INV; sgt[0].offset = 0; addr = dma_map_single(dev, skb->data,
@@ -1930,27 +1932,28 @@ static int skb_to_sg_fd(struct dpaa_priv *priv, qm_sg_entry_set64(&sgt[0], addr); /* populate the rest of SGT entries */ - frag = &skb_shinfo(skb)->frags[0]; - frag_len = frag->size; - for (i = 1; i <= nr_frags; i++, frag++) { + for (i = 0; i < nr_frags; i++) { + frag = &skb_shinfo(skb)->frags[i]; + buff_len = frag->size; WARN_ON(!skb_frag_page(frag)); addr = skb_frag_dma_map(dev, frag, 0, - frag_len, dma_dir); + buff_len, dma_dir); if (unlikely(dma_mapping_error(dev, addr))) { dev_err(dev, "DMA mapping failed"); err = -EINVAL; goto sg_map_failed; } - qm_sg_entry_set_len(&sgt[i], frag_len); - sgt[i].bpid = FSL_DPAA_BPID_INV; - sgt[i].offset = 0; + qm_sg_entry_set_len(&sgt[i + 1], buff_len); + sgt[i + 1].bpid = FSL_DPAA_BPID_INV; + sgt[i + 1].offset = 0; /* keep the offset in the address */ - qm_sg_entry_set64(&sgt[i], addr); - frag_len = frag->size; + qm_sg_entry_set64(&sgt[i + 1], addr); } - qm_sg_entry_set_f(&sgt[i - 1], frag_len); + + /* Set the final bit in the last used entry of the SGT */ + qm_sg_entry_set_f(&sgt[nr_frags], buff_len); qm_fd_set_sg(fd, priv->tx_headroom, skb->len);
--
2.1.0