6.6-stable review patch. If anyone has any objections, please let me know.
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From: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com
[ Upstream commit d2c96b9d5f83e4327cf044d00d7f713edd7fecfd ]
If the driver would like to transmit a jumbo frame like 2KiB or more, it should be split into multiple queues. In the near future, to support this, add handling specific descriptor types F{START,MID,END}. However, such jumbo frames will not happen yet because the maximum MTU size is still default for now.
Signed-off-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 0c9547e6ccf4 ("net: renesas: rswitch: fix race window between tx start and complete") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/renesas/rswitch.c | 56 +++++++++++++++++++++----- 1 file changed, 46 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c index c01b4bd3f812..17be2479654a 100644 --- a/drivers/net/ethernet/renesas/rswitch.c +++ b/drivers/net/ethernet/renesas/rswitch.c @@ -1561,15 +1561,44 @@ static bool rswitch_ext_desc_set(struct rswitch_device *rdev, return true; }
+static u8 rswitch_ext_desc_get_die_dt(unsigned int nr_desc, unsigned int index) +{ + if (nr_desc == 1) + return DT_FSINGLE | DIE; + if (index == 0) + return DT_FSTART; + if (nr_desc - 1 == index) + return DT_FEND | DIE; + return DT_FMID; +} + +static u16 rswitch_ext_desc_get_len(u8 die_dt, unsigned int orig_len) +{ + switch (die_dt & DT_MASK) { + case DT_FSINGLE: + case DT_FEND: + return (orig_len % RSWITCH_DESC_BUF_SIZE) ?: RSWITCH_DESC_BUF_SIZE; + case DT_FSTART: + case DT_FMID: + return RSWITCH_DESC_BUF_SIZE; + default: + return 0; + } +} + static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *ndev) { struct rswitch_device *rdev = netdev_priv(ndev); struct rswitch_gwca_queue *gq = rdev->tx_queue; + dma_addr_t dma_addr, dma_addr_orig; netdev_tx_t ret = NETDEV_TX_OK; struct rswitch_ext_desc *desc; - dma_addr_t dma_addr; + unsigned int i, nr_desc; + u8 die_dt; + u16 len;
- if (rswitch_get_num_cur_queues(gq) >= gq->ring_size - 1) { + nr_desc = (skb->len - 1) / RSWITCH_DESC_BUF_SIZE + 1; + if (rswitch_get_num_cur_queues(gq) >= gq->ring_size - nr_desc) { netif_stop_subqueue(ndev, 0); return NETDEV_TX_BUSY; } @@ -1577,25 +1606,32 @@ static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *nd if (skb_put_padto(skb, ETH_ZLEN)) return ret;
- dma_addr = dma_map_single(ndev->dev.parent, skb->data, skb->len, DMA_TO_DEVICE); - if (dma_mapping_error(ndev->dev.parent, dma_addr)) + dma_addr_orig = dma_map_single(ndev->dev.parent, skb->data, skb->len, DMA_TO_DEVICE); + if (dma_mapping_error(ndev->dev.parent, dma_addr_orig)) goto err_kfree;
gq->skbs[gq->cur] = skb; - gq->unmap_addrs[gq->cur] = dma_addr; - desc = &gq->tx_ring[gq->cur]; - if (!rswitch_ext_desc_set(rdev, skb, desc, dma_addr, skb->len, DT_FSINGLE | DIE)) - goto err_unmap; + gq->unmap_addrs[gq->cur] = dma_addr_orig; + + /* DT_FSTART should be set at last. So, this is reverse order. */ + for (i = nr_desc; i-- > 0; ) { + desc = &gq->tx_ring[rswitch_next_queue_index(gq, true, i)]; + die_dt = rswitch_ext_desc_get_die_dt(nr_desc, i); + dma_addr = dma_addr_orig + i * RSWITCH_DESC_BUF_SIZE; + len = rswitch_ext_desc_get_len(die_dt, skb->len); + if (!rswitch_ext_desc_set(rdev, skb, desc, dma_addr, len, die_dt)) + goto err_unmap; + }
wmb(); /* gq->cur must be incremented after die_dt was set */
- gq->cur = rswitch_next_queue_index(gq, true, 1); + gq->cur = rswitch_next_queue_index(gq, true, nr_desc); rswitch_modify(rdev->addr, GWTRC(gq->index), 0, BIT(gq->index % 32));
return ret;
err_unmap: - dma_unmap_single(ndev->dev.parent, dma_addr, skb->len, DMA_TO_DEVICE); + dma_unmap_single(ndev->dev.parent, dma_addr_orig, skb->len, DMA_TO_DEVICE);
err_kfree: dev_kfree_skb_any(skb);