From 6a00d0dd3fcfa2ef200973479fbeee62f3681130 Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Tue, 24 Mar 2020 13:23:44 +0000 Subject: net: axienet: Wrap DMA pointer writes to prepare for 64 bit Newer versions of the Xilink DMA IP support busses with more than 32 address bits, by introducing an MSB word for the registers holding DMA pointers (tail/current, RX/TX descriptor addresses). On IP configured for more than 32 bits, it is also *required* to write both words, to let the IP recognise this as a start condition for an MM2S request, for instance. Wrap the DMA pointer writes with a separate function, to add this functionality later. For now we stick to the lower 32 bits. Signed-off-by: Andre Przywara Signed-off-by: David S. Miller --- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 26 ++++++++++++++--------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index dc533d7a090c..e7469eb241ad 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -147,6 +147,12 @@ static inline void axienet_dma_out32(struct axienet_local *lp, iowrite32(value, lp->dma_regs + reg); } +static void axienet_dma_out_addr(struct axienet_local *lp, off_t reg, + dma_addr_t addr) +{ + axienet_dma_out32(lp, reg, lower_32_bits(addr)); +} + /** * axienet_dma_bd_release - Release buffer descriptor rings * @ndev: Pointer to the net_device structure @@ -285,18 +291,18 @@ static int axienet_dma_bd_init(struct net_device *ndev) /* Populate the tail pointer and bring the Rx Axi DMA engine out of * halted state. This will make the Rx side ready for reception. */ - axienet_dma_out32(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p); + axienet_dma_out_addr(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p); cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET); axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr | XAXIDMA_CR_RUNSTOP_MASK); - axienet_dma_out32(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p + - (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1))); + axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p + + (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1))); /* Write to the RS (Run-stop) bit in the Tx channel control register. * Tx channel is now ready to run. But only after we write to the * tail pointer register that the Tx channel will start transmitting. */ - axienet_dma_out32(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p); + axienet_dma_out_addr(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p); cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET); axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr | XAXIDMA_CR_RUNSTOP_MASK); @@ -757,7 +763,7 @@ axienet_start_xmit(struct sk_buff *skb, struct net_device *ndev) tail_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail; /* Start the transfer */ - axienet_dma_out32(lp, XAXIDMA_TX_TDESC_OFFSET, tail_p); + axienet_dma_out_addr(lp, XAXIDMA_TX_TDESC_OFFSET, tail_p); if (++lp->tx_bd_tail >= lp->tx_bd_num) lp->tx_bd_tail = 0; @@ -849,7 +855,7 @@ static void axienet_recv(struct net_device *ndev) ndev->stats.rx_bytes += size; if (tail_p) - axienet_dma_out32(lp, XAXIDMA_RX_TDESC_OFFSET, tail_p); + axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, tail_p); } /** @@ -1671,18 +1677,18 @@ static void axienet_dma_err_handler(struct work_struct *work) /* Populate the tail pointer and bring the Rx Axi DMA engine out of * halted state. This will make the Rx side ready for reception. */ - axienet_dma_out32(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p); + axienet_dma_out_addr(lp, XAXIDMA_RX_CDESC_OFFSET, lp->rx_bd_p); cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET); axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr | XAXIDMA_CR_RUNSTOP_MASK); - axienet_dma_out32(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p + - (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1))); + axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p + + (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1))); /* Write to the RS (Run-stop) bit in the Tx channel control register. * Tx channel is now ready to run. But only after we write to the * tail pointer register that the Tx channel will start transmitting */ - axienet_dma_out32(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p); + axienet_dma_out_addr(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p); cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET); axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr | XAXIDMA_CR_RUNSTOP_MASK); -- cgit v1.2.3-59-g8ed1b