5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andre Przywara andre.przywara@arm.com
[ Upstream commit ab365c3393664f32116aa22fe322cb04a93fab31 ]
Factor out the code that cleans up a number of connected TX descriptors, as we will need it to properly roll back a failed _xmit() call. There are subtle differences between cleaning up a successfully sent chain (unknown number of involved descriptors, total data size needed) and a chain that was about to set up (number of descriptors known), so cater for those variations with some extra parameters.
Signed-off-by: Andre Przywara andre.przywara@arm.com Reviewed-by: Radhey Shyam Pandey radhey.shyam.pandey@xilinx.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 9ff2f816e2aa ("net: axienet: Fix register defines comment description") Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/xilinx/xilinx_axienet_main.c | 79 +++++++++++++------ 1 file changed, 57 insertions(+), 22 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 22222d79e4902..4467719095432 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -546,32 +546,46 @@ static int axienet_device_reset(struct net_device *ndev) }
/** - * axienet_start_xmit_done - Invoked once a transmit is completed by the - * Axi DMA Tx channel. + * axienet_free_tx_chain - Clean up a series of linked TX descriptors. * @ndev: Pointer to the net_device structure + * @first_bd: Index of first descriptor to clean up + * @nr_bds: Number of descriptors to clean up, can be -1 if unknown. + * @sizep: Pointer to a u32 filled with the total sum of all bytes + * in all cleaned-up descriptors. Ignored if NULL. * - * This function is invoked from the Axi DMA Tx isr to notify the completion - * of transmit operation. It clears fields in the corresponding Tx BDs and - * unmaps the corresponding buffer so that CPU can regain ownership of the - * buffer. It finally invokes "netif_wake_queue" to restart transmission if - * required. + * Would either be called after a successful transmit operation, or after + * there was an error when setting up the chain. + * Returns the number of descriptors handled. */ -static void axienet_start_xmit_done(struct net_device *ndev) +static int axienet_free_tx_chain(struct net_device *ndev, u32 first_bd, + int nr_bds, u32 *sizep) { - u32 size = 0; - u32 packets = 0; struct axienet_local *lp = netdev_priv(ndev); struct axidma_bd *cur_p; - unsigned int status = 0; + int max_bds = nr_bds; + unsigned int status; + int i; + + if (max_bds == -1) + max_bds = lp->tx_bd_num; + + for (i = 0; i < max_bds; i++) { + cur_p = &lp->tx_bd_v[(first_bd + i) % lp->tx_bd_num]; + status = cur_p->status; + + /* If no number is given, clean up *all* descriptors that have + * been completed by the MAC. + */ + if (nr_bds == -1 && !(status & XAXIDMA_BD_STS_COMPLETE_MASK)) + break;
- cur_p = &lp->tx_bd_v[lp->tx_bd_ci]; - status = cur_p->status; - while (status & XAXIDMA_BD_STS_COMPLETE_MASK) { dma_unmap_single(ndev->dev.parent, cur_p->phys, (cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK), DMA_TO_DEVICE); - if (cur_p->skb) + + if (cur_p->skb && (status & XAXIDMA_BD_STS_COMPLETE_MASK)) dev_consume_skb_irq(cur_p->skb); + cur_p->cntrl = 0; cur_p->app0 = 0; cur_p->app1 = 0; @@ -580,15 +594,36 @@ static void axienet_start_xmit_done(struct net_device *ndev) cur_p->status = 0; cur_p->skb = NULL;
- size += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK; - packets++; - - if (++lp->tx_bd_ci >= lp->tx_bd_num) - lp->tx_bd_ci = 0; - cur_p = &lp->tx_bd_v[lp->tx_bd_ci]; - status = cur_p->status; + if (sizep) + *sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK; }
+ return i; +} + +/** + * axienet_start_xmit_done - Invoked once a transmit is completed by the + * Axi DMA Tx channel. + * @ndev: Pointer to the net_device structure + * + * This function is invoked from the Axi DMA Tx isr to notify the completion + * of transmit operation. It clears fields in the corresponding Tx BDs and + * unmaps the corresponding buffer so that CPU can regain ownership of the + * buffer. It finally invokes "netif_wake_queue" to restart transmission if + * required. + */ +static void axienet_start_xmit_done(struct net_device *ndev) +{ + struct axienet_local *lp = netdev_priv(ndev); + u32 packets = 0; + u32 size = 0; + + packets = axienet_free_tx_chain(ndev, lp->tx_bd_ci, -1, &size); + + lp->tx_bd_ci += packets; + if (lp->tx_bd_ci >= lp->tx_bd_num) + lp->tx_bd_ci -= lp->tx_bd_num; + ndev->stats.tx_packets += packets; ndev->stats.tx_bytes += size;