/**
* axienet_dma_bd_init - Setup buffer descriptor rings for Axi DMA
* @ndev: Pointer to the net_device structure
*
* Return: 0, on success -ENOMEM, on failure
*
* This function is called to initialize the Rx and Tx DMA descriptor
* rings. This initializes the descriptors with required default values
* and is called when Axi Ethernet driver reset is called.
*/
static int axienet_dma_bd_init(struct net_device *ndev)
{
u32 cr;
int i;
struct sk_buff *skb;
struct axienet_local *lp = netdev_priv(ndev);
/* Reset the indexes which are used for accessing the BDs */
lp->tx_bd_ci = 0;
lp->tx_bd_tail = 0;
lp->rx_bd_ci = 0;
/* Allocate the Tx and Rx buffer descriptors. */
lp->tx_bd_v = dma_zalloc_coherent(ndev->dev.parent,
sizeof(*lp->tx_bd_v) * TX_BD_NUM,
&lp->tx_bd_p, GFP_KERNEL);
if (!lp->tx_bd_v)
goto out;
lp->rx_bd_v = dma_zalloc_coherent(ndev->dev.parent,
sizeof(*lp->rx_bd_v) * RX_BD_NUM,
&lp->rx_bd_p, GFP_KERNEL);
if (!lp->rx_bd_v)
goto out;
for (i = 0; i < TX_BD_NUM; i++) {
lp->tx_bd_v[i].next = lp->tx_bd_p +
sizeof(*lp->tx_bd_v) *
((i + 1) % TX_BD_NUM);
}
for (i = 0; i < RX_BD_NUM; i++) {
lp->rx_bd_v[i].next = lp->rx_bd_p +
sizeof(*lp->rx_bd_v) *
((i + 1) % RX_BD_NUM);
skb = netdev_alloc_skb_ip_align(ndev, lp->max_frm_size);
if (!skb)
goto out;
lp->rx_bd_v[i].sw_id_offset = (u32) skb;
lp->rx_bd_v[i].phys = dma_map_single(ndev->dev.parent,
skb->data,
lp->max_frm_size,
DMA_FROM_DEVICE);
lp->rx_bd_v[i].cntrl = lp->max_frm_size;
}
/* Start updating the Rx channel control register */
cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
/* Update the interrupt coalesce count */
cr = ((cr & ~XAXIDMA_COALESCE_MASK) |
((lp->coalesce_count_rx) << XAXIDMA_COALESCE_SHIFT));
/* Update the delay timer count */
cr = ((cr & ~XAXIDMA_DELAY_MASK) |
(XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
/* Enable coalesce, delay timer and error interrupts */
cr |= XAXIDMA_IRQ_ALL_MASK;
/* Write to the Rx channel control register */
axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
/* Start updating the Tx channel control register */
cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
/* Update the interrupt coalesce count */
cr = (((cr & ~XAXIDMA_COALESCE_MASK)) |
((lp->coalesce_count_tx) << XAXIDMA_COALESCE_SHIFT));
/* Update the delay timer count */
cr = (((cr & ~XAXIDMA_DELAY_MASK)) |
(XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
/* Enable coalesce, delay timer and error interrupts */
cr |= XAXIDMA_IRQ_ALL_MASK;
/* Write to the Tx channel control register */
axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
/* 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);
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) * (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);
cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET,
cr | XAXIDMA_CR_RUNSTOP_MASK);
return 0;
out:
axienet_dma_bd_release(ndev);
return -ENOMEM;
}
static int axienet_dma_bd_init(struct net_device *ndev)
{
u32 cr;
int i;
struct sk_buff *skb;
struct axienet_local *lp = netdev_priv(ndev);
lp->tx_bd_ci = 0;
lp->tx_bd_tail = 0;
lp->rx_bd_ci = 0;
lp->tx_bd_v = dma_alloc_coherent(ndev->dev.parent,
sizeof(*lp->tx_bd_v) * TX_BD_NUM,
&lp->tx_bd_p,
GFP_KERNEL);
if (!lp->tx_bd_v) {
dev_err(&ndev->dev, "unable to allocate DMA Tx buffer "
"descriptors");
goto out;
}
lp->rx_bd_v = dma_alloc_coherent(ndev->dev.parent,
sizeof(*lp->rx_bd_v) * RX_BD_NUM,
&lp->rx_bd_p,
GFP_KERNEL);
if (!lp->rx_bd_v) {
dev_err(&ndev->dev, "unable to allocate DMA Rx buffer "
"descriptors");
goto out;
}
memset(lp->tx_bd_v, 0, sizeof(*lp->tx_bd_v) * TX_BD_NUM);
for (i = 0; i < TX_BD_NUM; i++) {
lp->tx_bd_v[i].next = lp->tx_bd_p +
sizeof(*lp->tx_bd_v) *
((i + 1) % TX_BD_NUM);
}
memset(lp->rx_bd_v, 0, sizeof(*lp->rx_bd_v) * RX_BD_NUM);
for (i = 0; i < RX_BD_NUM; i++) {
lp->rx_bd_v[i].next = lp->rx_bd_p +
sizeof(*lp->rx_bd_v) *
((i + 1) % RX_BD_NUM);
skb = netdev_alloc_skb_ip_align(ndev, lp->max_frm_size);
if (!skb) {
dev_err(&ndev->dev, "alloc_skb error %d\n", i);
goto out;
}
lp->rx_bd_v[i].sw_id_offset = (u32) skb;
lp->rx_bd_v[i].phys = dma_map_single(ndev->dev.parent,
skb->data,
lp->max_frm_size,
DMA_FROM_DEVICE);
lp->rx_bd_v[i].cntrl = lp->max_frm_size;
}
cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
cr = ((cr & ~XAXIDMA_COALESCE_MASK) |
((lp->coalesce_count_rx) << XAXIDMA_COALESCE_SHIFT));
cr = ((cr & ~XAXIDMA_DELAY_MASK) |
(XAXIDMA_DFT_RX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
cr |= XAXIDMA_IRQ_ALL_MASK;
axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
cr = (((cr & ~XAXIDMA_COALESCE_MASK)) |
((lp->coalesce_count_tx) << XAXIDMA_COALESCE_SHIFT));
cr = (((cr & ~XAXIDMA_DELAY_MASK)) |
(XAXIDMA_DFT_TX_WAITBOUND << XAXIDMA_DELAY_SHIFT));
cr |= XAXIDMA_IRQ_ALL_MASK;
axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
axienet_dma_out32(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) * (RX_BD_NUM - 1)));
axienet_dma_out32(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);
return 0;
out:
axienet_dma_bd_release(ndev);
return -ENOMEM;
}
