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Commit a47b70ea authored by Kazuya Mizuguchi's avatar Kazuya Mizuguchi Committed by David S. Miller
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ravb: unmap descriptors when freeing rings 



"swiotlb buffer is full" errors occur after repeated initialisation of a
device - f.e. suspend/resume or ip link set up/down. This is because memory
mapped using dma_map_single() in ravb_ring_format() and ravb_start_xmit()
is not released.  Resolve this problem by unmapping descriptors when
freeing rings.

Fixes: c156633f ("Renesas Ethernet AVB driver proper")
Signed-off-by: default avatarKazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
[simon: reworked]
Signed-off-by: default avatarSimon Horman <horms+renesas@verge.net.au>
Acked-by: default avatarSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 086cb6a4

drivers/net/ethernet/renesas/ravb_main.c

+64 −48
Original line number Diff line number Diff line
@@ -179,6 +179,49 @@ static struct mdiobb_ops bb_ops = { 
	.get_mdio_data = ravb_get_mdio_data,

};



/* Free TX skb function for AVB-IP */

static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only)

{

	struct ravb_private *priv = netdev_priv(ndev);

	struct net_device_stats *stats = &priv->stats[q];

	struct ravb_tx_desc *desc;

	int free_num = 0;

	int entry;

	u32 size;



	for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {

		bool txed;



		entry = priv->dirty_tx[q] % (priv->num_tx_ring[q] *

					     NUM_TX_DESC);

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

		txed = desc->die_dt == DT_FEMPTY;

		if (free_txed_only && !txed)

			break;

		/* Descriptor type must be checked before all other reads */

		dma_rmb();

		size = le16_to_cpu(desc->ds_tagl) & TX_DS;

		/* Free the original skb. */

		if (priv->tx_skb[q][entry / NUM_TX_DESC]) {

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

					 size, DMA_TO_DEVICE);

			/* Last packet descriptor? */

			if (entry % NUM_TX_DESC == NUM_TX_DESC - 1) {

				entry /= NUM_TX_DESC;

				dev_kfree_skb_any(priv->tx_skb[q][entry]);

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

				if (txed)

					stats->tx_packets++;

			}

			free_num++;

		}

		if (txed)

			stats->tx_bytes += size;

		desc->die_dt = DT_EEMPTY;

	}

	return free_num;

}



/* Free skb's and DMA buffers for Ethernet AVB */

static void ravb_ring_free(struct net_device *ndev, int q)

{
@@ -194,19 +237,21 @@ static void ravb_ring_free(struct net_device *ndev, int q) 
	kfree(priv->rx_skb[q]);

	priv->rx_skb[q] = NULL;



	/* Free TX skb ringbuffer */

	if (priv->tx_skb[q]) {

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

			dev_kfree_skb(priv->tx_skb[q][i]);

	}

	kfree(priv->tx_skb[q]);

	priv->tx_skb[q] = NULL;



	/* Free aligned TX buffers */

	kfree(priv->tx_align[q]);

	priv->tx_align[q] = NULL;



	if (priv->rx_ring[q]) {

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

			struct ravb_ex_rx_desc *desc = &priv->rx_ring[q][i];



			if (!dma_mapping_error(ndev->dev.parent,

					       le32_to_cpu(desc->dptr)))

				dma_unmap_single(ndev->dev.parent,

						 le32_to_cpu(desc->dptr),

						 PKT_BUF_SZ,

						 DMA_FROM_DEVICE);

		}

		ring_size = sizeof(struct ravb_ex_rx_desc) *

			    (priv->num_rx_ring[q] + 1);

		dma_free_coherent(ndev->dev.parent, ring_size, priv->rx_ring[q],
@@ -215,12 +260,20 @@ static void ravb_ring_free(struct net_device *ndev, int q) 
	}



	if (priv->tx_ring[q]) {

		ravb_tx_free(ndev, q, false);



		ring_size = sizeof(struct ravb_tx_desc) *

			    (priv->num_tx_ring[q] * NUM_TX_DESC + 1);

		dma_free_coherent(ndev->dev.parent, ring_size, priv->tx_ring[q],

				  priv->tx_desc_dma[q]);

		priv->tx_ring[q] = NULL;

	}



	/* Free TX skb ringbuffer.

	 * SKBs are freed by ravb_tx_free() call above.

	 */

	kfree(priv->tx_skb[q]);

	priv->tx_skb[q] = NULL;

}



/* Format skb and descriptor buffer for Ethernet AVB */
@@ -431,44 +484,6 @@ static int ravb_dmac_init(struct net_device *ndev) 
	return 0;

}



/* Free TX skb function for AVB-IP */

static int ravb_tx_free(struct net_device *ndev, int q)

{

	struct ravb_private *priv = netdev_priv(ndev);

	struct net_device_stats *stats = &priv->stats[q];

	struct ravb_tx_desc *desc;

	int free_num = 0;

	int entry;

	u32 size;



	for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {

		entry = priv->dirty_tx[q] % (priv->num_tx_ring[q] *

					     NUM_TX_DESC);

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

		if (desc->die_dt != DT_FEMPTY)

			break;

		/* Descriptor type must be checked before all other reads */

		dma_rmb();

		size = le16_to_cpu(desc->ds_tagl) & TX_DS;

		/* Free the original skb. */

		if (priv->tx_skb[q][entry / NUM_TX_DESC]) {

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

					 size, DMA_TO_DEVICE);

			/* Last packet descriptor? */

			if (entry % NUM_TX_DESC == NUM_TX_DESC - 1) {

				entry /= NUM_TX_DESC;

				dev_kfree_skb_any(priv->tx_skb[q][entry]);

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

				stats->tx_packets++;

			}

			free_num++;

		}

		stats->tx_bytes += size;

		desc->die_dt = DT_EEMPTY;

	}

	return free_num;

}



static void ravb_get_tx_tstamp(struct net_device *ndev)

{

	struct ravb_private *priv = netdev_priv(ndev);
@@ -902,7 +917,7 @@ static int ravb_poll(struct napi_struct *napi, int budget) 
			spin_lock_irqsave(&priv->lock, flags);

			/* Clear TX interrupt */

			ravb_write(ndev, ~mask, TIS);

			ravb_tx_free(ndev, q);

			ravb_tx_free(ndev, q, true);

			netif_wake_subqueue(ndev, q);

			mmiowb();

			spin_unlock_irqrestore(&priv->lock, flags);
@@ -1567,7 +1582,8 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) 


	priv->cur_tx[q] += NUM_TX_DESC;

	if (priv->cur_tx[q] - priv->dirty_tx[q] >

	    (priv->num_tx_ring[q] - 1) * NUM_TX_DESC && !ravb_tx_free(ndev, q))

	    (priv->num_tx_ring[q] - 1) * NUM_TX_DESC &&

	    !ravb_tx_free(ndev, q, true))

		netif_stop_subqueue(ndev, q);



exit: