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Commit 15fb35fa authored by Ulrich Hecht's avatar Ulrich Hecht Committed by David S. Miller
Browse files

ravb: implement MTU change while device is up 



Pre-allocates buffers sufficient for the maximum supported MTU (2026) in
order to eliminate the possibility of resource exhaustion when changing the
MTU while the device is up.

Signed-off-by: default avatarUlrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: default avatarSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d7f9f47d

drivers/net/ethernet/renesas/ravb.h

+2 −1
Original line number Diff line number Diff line
@@ -955,6 +955,8 @@ enum RAVB_QUEUE { 
#define NUM_RX_QUEUE	2

#define NUM_TX_QUEUE	2



#define RX_BUF_SZ	(2048 - ETH_FCS_LEN + sizeof(__sum16))



/* TX descriptors per packet */

#define NUM_TX_DESC_GEN2	2

#define NUM_TX_DESC_GEN3	1
@@ -1018,7 +1020,6 @@ struct ravb_private { 
	u32 dirty_rx[NUM_RX_QUEUE];	/* Producer ring indices */

	u32 cur_tx[NUM_TX_QUEUE];

	u32 dirty_tx[NUM_TX_QUEUE];

	u32 rx_buf_sz;			/* Based on MTU+slack. */

	struct napi_struct napi[NUM_RX_QUEUE];

	struct work_struct work;

	/* MII transceiver section. */

drivers/net/ethernet/renesas/ravb_main.c

+14 −12
Original line number Diff line number Diff line
@@ -230,7 +230,7 @@ static void ravb_ring_free(struct net_device *ndev, int q) 
					       le32_to_cpu(desc->dptr)))

				dma_unmap_single(ndev->dev.parent,

						 le32_to_cpu(desc->dptr),

						 priv->rx_buf_sz,

						 RX_BUF_SZ,

						 DMA_FROM_DEVICE);

		}

		ring_size = sizeof(struct ravb_ex_rx_desc) *
@@ -293,9 +293,9 @@ static void ravb_ring_format(struct net_device *ndev, int q) 
	for (i = 0; i < priv->num_rx_ring[q]; i++) {

		/* RX descriptor */

		rx_desc = &priv->rx_ring[q][i];

		rx_desc->ds_cc = cpu_to_le16(priv->rx_buf_sz);

		rx_desc->ds_cc = cpu_to_le16(RX_BUF_SZ);

		dma_addr = dma_map_single(ndev->dev.parent, priv->rx_skb[q][i]->data,

					  priv->rx_buf_sz,

					  RX_BUF_SZ,

					  DMA_FROM_DEVICE);

		/* We just set the data size to 0 for a failed mapping which

		 * should prevent DMA from happening...
@@ -342,9 +342,6 @@ static int ravb_ring_init(struct net_device *ndev, int q) 
	int ring_size;

	int i;



	priv->rx_buf_sz = (ndev->mtu <= 1492 ? PKT_BUF_SZ : ndev->mtu) +

		ETH_HLEN + VLAN_HLEN + sizeof(__sum16);



	/* Allocate RX and TX skb rings */

	priv->rx_skb[q] = kcalloc(priv->num_rx_ring[q],

				  sizeof(*priv->rx_skb[q]), GFP_KERNEL);
@@ -354,7 +351,7 @@ static int ravb_ring_init(struct net_device *ndev, int q) 
		goto error;



	for (i = 0; i < priv->num_rx_ring[q]; i++) {

		skb = netdev_alloc_skb(ndev, priv->rx_buf_sz + RAVB_ALIGN - 1);

		skb = netdev_alloc_skb(ndev, RX_BUF_SZ + RAVB_ALIGN - 1);

		if (!skb)

			goto error;

		ravb_set_buffer_align(skb);
@@ -584,7 +581,7 @@ static bool ravb_rx(struct net_device *ndev, int *quota, int q) 
			skb = priv->rx_skb[q][entry];

			priv->rx_skb[q][entry] = NULL;

			dma_unmap_single(ndev->dev.parent, le32_to_cpu(desc->dptr),

					 priv->rx_buf_sz,

					 RX_BUF_SZ,

					 DMA_FROM_DEVICE);

			get_ts &= (q == RAVB_NC) ?

					RAVB_RXTSTAMP_TYPE_V2_L2_EVENT :
@@ -617,11 +614,11 @@ static bool ravb_rx(struct net_device *ndev, int *quota, int q) 
	for (; priv->cur_rx[q] - priv->dirty_rx[q] > 0; priv->dirty_rx[q]++) {

		entry = priv->dirty_rx[q] % priv->num_rx_ring[q];

		desc = &priv->rx_ring[q][entry];

		desc->ds_cc = cpu_to_le16(priv->rx_buf_sz);

		desc->ds_cc = cpu_to_le16(RX_BUF_SZ);



		if (!priv->rx_skb[q][entry]) {

			skb = netdev_alloc_skb(ndev,

					       priv->rx_buf_sz +

					       RX_BUF_SZ +

					       RAVB_ALIGN - 1);

			if (!skb)

				break;	/* Better luck next round. */
@@ -1801,10 +1798,15 @@ static int ravb_do_ioctl(struct net_device *ndev, struct ifreq *req, int cmd) 


static int ravb_change_mtu(struct net_device *ndev, int new_mtu)

{

	if (netif_running(ndev))

		return -EBUSY;

	struct ravb_private *priv = netdev_priv(ndev);



	ndev->mtu = new_mtu;



	if (netif_running(ndev)) {

		synchronize_irq(priv->emac_irq);

		ravb_emac_init(ndev);

	}



	netdev_update_features(ndev);



	return 0;