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net: axienet: Wrap DMA pointer writes to prepare for 64 bit

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[ Upstream commit 6a00d0dd3fcfa2ef200973479fbeee62f3681130 ]

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 <andre.przywara@arm.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>
This commit is contained in:
Andre Przywara 2020-03-24 13:23:44 +00:00 • committed by Greg Kroah-Hartman
parent 2978228525
commit 67527bcb0f
1 changed files with 16 additions and 10 deletions
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26
drivers/net/ethernet/xilinx/xilinx_axienet_main.c
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@ -148,6 +148,12 @@ 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
@ -286,18 +292,18 @@ 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);
@ -758,7 +764,7 @@ 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;
@ -850,7 +856,7 @@ 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);
}
/**
@ -1683,18 +1689,18 @@ 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);