| Message ID | E1pjOwe-00Fmki-6p@rmk-PC.armlinux.org.uk (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: mvneta: reduce size of TSO header allocation | expand |
On Mon, Apr 3, 2023 at 8:30 PM Russell King (Oracle) <rmk+kernel@armlinux.org.uk> wrote: > > The transmit code assumes that the transmit descriptors that are used > begin with the first descriptor in the ring, but this may not be the > case. Fix this by providing a new function that dma-unmaps a range of > numbered descriptor entries, and use that to do the unmapping. > > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Nice patch series ! I guess this one will need to be backported to stable versions. It would be nice adding: Fixes: 2adb719d74f6 ("net: mvneta: Implement software TSO") Thanks. > --- > drivers/net/ethernet/marvell/mvneta.c | 53 +++++++++++++++++---------- > 1 file changed, 33 insertions(+), 20 deletions(-) > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c > index 2cad76d0a50e..62400ff61e34 100644 > --- a/drivers/net/ethernet/marvell/mvneta.c > +++ b/drivers/net/ethernet/marvell/mvneta.c > @@ -2714,14 +2714,40 @@ mvneta_tso_put_data(struct net_device *dev, struct mvneta_tx_queue *txq, > return 0; > } > > +static void mvneta_release_descs(struct mvneta_port *pp, > + struct mvneta_tx_queue *txq, > + int first, int num) > +{ > + int desc_idx, i; > + > + desc_idx = first + num; > + if (desc_idx >= txq->size) > + desc_idx -= txq->size; > + > + for (i = num; i >= 0; i--) { > + struct mvneta_tx_desc *tx_desc = txq->descs + desc_idx; > + > + if (!IS_TSO_HEADER(txq, tx_desc->buf_phys_addr)) > + dma_unmap_single(pp->dev->dev.parent, > + tx_desc->buf_phys_addr, > + tx_desc->data_size, > + DMA_TO_DEVICE); > + > + mvneta_txq_desc_put(txq); > + > + if (desc_idx == 0) > + desc_idx = txq->size; > + desc_idx -= 1; > + } > +} > + > static int mvneta_tx_tso(struct sk_buff *skb, struct net_device *dev, > struct mvneta_tx_queue *txq) > { > int hdr_len, total_len, data_left; > - int desc_count = 0; > + int first_desc, desc_count = 0; > struct mvneta_port *pp = netdev_priv(dev); > struct tso_t tso; > - int i; > > /* Count needed descriptors */ > if ((txq->count + tso_count_descs(skb)) >= txq->size) > @@ -2732,6 +2758,8 @@ static int mvneta_tx_tso(struct sk_buff *skb, struct net_device *dev, > return 0; > } > > + first_desc = txq->txq_put_index; > + > /* Initialize the TSO handler, and prepare the first payload */ > hdr_len = tso_start(skb, &tso); > > @@ -2772,15 +2800,7 @@ static int mvneta_tx_tso(struct sk_buff *skb, struct net_device *dev, > /* Release all used data descriptors; header descriptors must not > * be DMA-unmapped. > */ > - for (i = desc_count - 1; i >= 0; i--) { > - struct mvneta_tx_desc *tx_desc = txq->descs + i; > - if (!IS_TSO_HEADER(txq, tx_desc->buf_phys_addr)) > - dma_unmap_single(pp->dev->dev.parent, > - tx_desc->buf_phys_addr, > - tx_desc->data_size, > - DMA_TO_DEVICE); > - mvneta_txq_desc_put(txq); > - } > + mvneta_release_descs(pp, txq, first_desc, desc_count - 1); > return 0; > } > > @@ -2790,6 +2810,7 @@ static int mvneta_tx_frag_process(struct mvneta_port *pp, struct sk_buff *skb, > { > struct mvneta_tx_desc *tx_desc; > int i, nr_frags = skb_shinfo(skb)->nr_frags; > + int first_desc = txq->txq_put_index; > > for (i = 0; i < nr_frags; i++) { > struct mvneta_tx_buf *buf = &txq->buf[txq->txq_put_index]; > @@ -2828,15 +2849,7 @@ static int mvneta_tx_frag_process(struct mvneta_port *pp, struct sk_buff *skb, > /* Release all descriptors that were used to map fragments of > * this packet, as well as the corresponding DMA mappings > */ > - for (i = i - 1; i >= 0; i--) { > - tx_desc = txq->descs + i; > - dma_unmap_single(pp->dev->dev.parent, > - tx_desc->buf_phys_addr, > - tx_desc->data_size, > - DMA_TO_DEVICE); > - mvneta_txq_desc_put(txq); > - } > - > + mvneta_release_descs(pp, txq, first_desc, i - 1); > return -ENOMEM; > } > > -- > 2.30.2 >
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 2cad76d0a50e..62400ff61e34 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -2714,14 +2714,40 @@ mvneta_tso_put_data(struct net_device *dev, struct mvneta_tx_queue *txq, return 0; } +static void mvneta_release_descs(struct mvneta_port *pp, + struct mvneta_tx_queue *txq, + int first, int num) +{ + int desc_idx, i; + + desc_idx = first + num; + if (desc_idx >= txq->size) + desc_idx -= txq->size; + + for (i = num; i >= 0; i--) { + struct mvneta_tx_desc *tx_desc = txq->descs + desc_idx; + + if (!IS_TSO_HEADER(txq, tx_desc->buf_phys_addr)) + dma_unmap_single(pp->dev->dev.parent, + tx_desc->buf_phys_addr, + tx_desc->data_size, + DMA_TO_DEVICE); + + mvneta_txq_desc_put(txq); + + if (desc_idx == 0) + desc_idx = txq->size; + desc_idx -= 1; + } +} + static int mvneta_tx_tso(struct sk_buff *skb, struct net_device *dev, struct mvneta_tx_queue *txq) { int hdr_len, total_len, data_left; - int desc_count = 0; + int first_desc, desc_count = 0; struct mvneta_port *pp = netdev_priv(dev); struct tso_t tso; - int i; /* Count needed descriptors */ if ((txq->count + tso_count_descs(skb)) >= txq->size) @@ -2732,6 +2758,8 @@ static int mvneta_tx_tso(struct sk_buff *skb, struct net_device *dev, return 0; } + first_desc = txq->txq_put_index; + /* Initialize the TSO handler, and prepare the first payload */ hdr_len = tso_start(skb, &tso); @@ -2772,15 +2800,7 @@ static int mvneta_tx_tso(struct sk_buff *skb, struct net_device *dev, /* Release all used data descriptors; header descriptors must not * be DMA-unmapped. */ - for (i = desc_count - 1; i >= 0; i--) { - struct mvneta_tx_desc *tx_desc = txq->descs + i; - if (!IS_TSO_HEADER(txq, tx_desc->buf_phys_addr)) - dma_unmap_single(pp->dev->dev.parent, - tx_desc->buf_phys_addr, - tx_desc->data_size, - DMA_TO_DEVICE); - mvneta_txq_desc_put(txq); - } + mvneta_release_descs(pp, txq, first_desc, desc_count - 1); return 0; } @@ -2790,6 +2810,7 @@ static int mvneta_tx_frag_process(struct mvneta_port *pp, struct sk_buff *skb, { struct mvneta_tx_desc *tx_desc; int i, nr_frags = skb_shinfo(skb)->nr_frags; + int first_desc = txq->txq_put_index; for (i = 0; i < nr_frags; i++) { struct mvneta_tx_buf *buf = &txq->buf[txq->txq_put_index]; @@ -2828,15 +2849,7 @@ static int mvneta_tx_frag_process(struct mvneta_port *pp, struct sk_buff *skb, /* Release all descriptors that were used to map fragments of * this packet, as well as the corresponding DMA mappings */ - for (i = i - 1; i >= 0; i--) { - tx_desc = txq->descs + i; - dma_unmap_single(pp->dev->dev.parent, - tx_desc->buf_phys_addr, - tx_desc->data_size, - DMA_TO_DEVICE); - mvneta_txq_desc_put(txq); - } - + mvneta_release_descs(pp, txq, first_desc, i - 1); return -ENOMEM; }
The transmit code assumes that the transmit descriptors that are used begin with the first descriptor in the ring, but this may not be the case. Fix this by providing a new function that dma-unmaps a range of numbered descriptor entries, and use that to do the unmapping. Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- drivers/net/ethernet/marvell/mvneta.c | 53 +++++++++++++++++---------- 1 file changed, 33 insertions(+), 20 deletions(-)