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Commit e344e97f authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by Greg Kroah-Hartman
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sh_eth: unmap DMA buffers when freeing rings 



[ Upstream commit 1debdc8f9ebd07daf140e417b3841596911e0066 ]

The DMA API debugging (when enabled) causes:

WARNING: CPU: 0 PID: 1445 at lib/dma-debug.c:519 add_dma_entry+0xe0/0x12c
DMA-API: exceeded 7 overlapping mappings of cacheline 0x01b2974d

to be  printed after repeated initialization of the Ether device, e.g.
suspend/resume or 'ifconfig' up/down. This is because DMA buffers mapped
using dma_map_single() in sh_eth_ring_format() and sh_eth_start_xmit() are
never unmapped. Resolve this problem by unmapping the buffers when freeing
the descriptor  rings;  in order  to do it right, we'd have to add an extra
parameter to sh_eth_txfree() (we rename this function to sh_eth_tx_free(),
while at it).

Based on the commit a47b70ea86bd ("ravb: unmap descriptors when freeing
rings").

Signed-off-by: default avatarSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b4580d6f

drivers/net/ethernet/renesas/sh_eth.c

+67 −55
Original line number Diff line number Diff line
@@ -1059,41 +1059,90 @@ static struct mdiobb_ops bb_ops = { 
	.get_mdio_data = sh_get_mdio,

};



/* free skb and descriptor buffer */

static void sh_eth_ring_free(struct net_device *ndev)

/* free Tx skb function */

static int sh_eth_tx_free(struct net_device *ndev, bool sent_only)

{

	struct sh_eth_private *mdp = netdev_priv(ndev);

	int ringsize, i;

	struct sh_eth_txdesc *txdesc;

	int free_num = 0;

	int entry;

	bool sent;



	/* Free Rx skb ringbuffer */

	if (mdp->rx_skbuff) {

		for (i = 0; i < mdp->num_rx_ring; i++)

			dev_kfree_skb(mdp->rx_skbuff[i]);

	for (; mdp->cur_tx - mdp->dirty_tx > 0; mdp->dirty_tx++) {

		entry = mdp->dirty_tx % mdp->num_tx_ring;

		txdesc = &mdp->tx_ring[entry];

		sent = !(txdesc->status & cpu_to_le32(TD_TACT));

		if (sent_only && !sent)

			break;

		/* TACT bit must be checked before all the following reads */

		dma_rmb();

		netif_info(mdp, tx_done, ndev,

			   "tx entry %d status 0x%08x\n",

			   entry, le32_to_cpu(txdesc->status));

		/* Free the original skb. */

		if (mdp->tx_skbuff[entry]) {

			dma_unmap_single(&ndev->dev, le32_to_cpu(txdesc->addr),

					 le32_to_cpu(txdesc->len) >> 16,

					 DMA_TO_DEVICE);

			dev_kfree_skb_irq(mdp->tx_skbuff[entry]);

			mdp->tx_skbuff[entry] = NULL;

			free_num++;

		}

	kfree(mdp->rx_skbuff);

	mdp->rx_skbuff = NULL;

		txdesc->status = cpu_to_le32(TD_TFP);

		if (entry >= mdp->num_tx_ring - 1)

			txdesc->status |= cpu_to_le32(TD_TDLE);



	/* Free Tx skb ringbuffer */

	if (mdp->tx_skbuff) {

		for (i = 0; i < mdp->num_tx_ring; i++)

			dev_kfree_skb(mdp->tx_skbuff[i]);

		if (sent) {

			ndev->stats.tx_packets++;

			ndev->stats.tx_bytes += le32_to_cpu(txdesc->len) >> 16;

		}

	}

	return free_num;

}

	kfree(mdp->tx_skbuff);

	mdp->tx_skbuff = NULL;



/* free skb and descriptor buffer */

static void sh_eth_ring_free(struct net_device *ndev)

{

	struct sh_eth_private *mdp = netdev_priv(ndev);

	int ringsize, i;



	if (mdp->rx_ring) {

		for (i = 0; i < mdp->num_rx_ring; i++) {

			if (mdp->rx_skbuff[i]) {

				struct sh_eth_rxdesc *rxdesc = &mdp->rx_ring[i];



				dma_unmap_single(&ndev->dev,

						 le32_to_cpu(rxdesc->addr),

						 ALIGN(mdp->rx_buf_sz, 32),

						 DMA_FROM_DEVICE);

			}

		}

		ringsize = sizeof(struct sh_eth_rxdesc) * mdp->num_rx_ring;

		dma_free_coherent(NULL, ringsize, mdp->rx_ring,

				  mdp->rx_desc_dma);

		mdp->rx_ring = NULL;

	}



	/* Free Rx skb ringbuffer */

	if (mdp->rx_skbuff) {

		for (i = 0; i < mdp->num_rx_ring; i++)

			dev_kfree_skb(mdp->rx_skbuff[i]);

	}

	kfree(mdp->rx_skbuff);

	mdp->rx_skbuff = NULL;



	if (mdp->tx_ring) {

		sh_eth_tx_free(ndev, false);



		ringsize = sizeof(struct sh_eth_txdesc) * mdp->num_tx_ring;

		dma_free_coherent(NULL, ringsize, mdp->tx_ring,

				  mdp->tx_desc_dma);

		mdp->tx_ring = NULL;

	}



	/* Free Tx skb ringbuffer */

	kfree(mdp->tx_skbuff);

	mdp->tx_skbuff = NULL;

}



/* format skb and descriptor buffer */
@@ -1341,43 +1390,6 @@ static void sh_eth_dev_exit(struct net_device *ndev) 
	update_mac_address(ndev);

}



/* free Tx skb function */

static int sh_eth_txfree(struct net_device *ndev)

{

	struct sh_eth_private *mdp = netdev_priv(ndev);

	struct sh_eth_txdesc *txdesc;

	int free_num = 0;

	int entry;



	for (; mdp->cur_tx - mdp->dirty_tx > 0; mdp->dirty_tx++) {

		entry = mdp->dirty_tx % mdp->num_tx_ring;

		txdesc = &mdp->tx_ring[entry];

		if (txdesc->status & cpu_to_le32(TD_TACT))

			break;

		/* TACT bit must be checked before all the following reads */

		dma_rmb();

		netif_info(mdp, tx_done, ndev,

			   "tx entry %d status 0x%08x\n",

			   entry, le32_to_cpu(txdesc->status));

		/* Free the original skb. */

		if (mdp->tx_skbuff[entry]) {

			dma_unmap_single(&ndev->dev, le32_to_cpu(txdesc->addr),

					 le32_to_cpu(txdesc->len) >> 16,

					 DMA_TO_DEVICE);

			dev_kfree_skb_irq(mdp->tx_skbuff[entry]);

			mdp->tx_skbuff[entry] = NULL;

			free_num++;

		}

		txdesc->status = cpu_to_le32(TD_TFP);

		if (entry >= mdp->num_tx_ring - 1)

			txdesc->status |= cpu_to_le32(TD_TDLE);



		ndev->stats.tx_packets++;

		ndev->stats.tx_bytes += le32_to_cpu(txdesc->len) >> 16;

	}

	return free_num;

}



/* Packet receive function */

static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota)

{
@@ -1620,7 +1632,7 @@ static void sh_eth_error(struct net_device *ndev, u32 intr_status) 
			   intr_status, mdp->cur_tx, mdp->dirty_tx,

			   (u32)ndev->state, edtrr);

		/* dirty buffer free */

		sh_eth_txfree(ndev);

		sh_eth_tx_free(ndev, true);



		/* SH7712 BUG */

		if (edtrr ^ sh_eth_get_edtrr_trns(mdp)) {
@@ -1679,7 +1691,7 @@ static irqreturn_t sh_eth_interrupt(int irq, void *netdev) 
		/* Clear Tx interrupts */

		sh_eth_write(ndev, intr_status & cd->tx_check, EESR);



		sh_eth_txfree(ndev);

		sh_eth_tx_free(ndev, true);

		netif_wake_queue(ndev);

	}
@@ -2307,7 +2319,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev) 


	spin_lock_irqsave(&mdp->lock, flags);

	if ((mdp->cur_tx - mdp->dirty_tx) >= (mdp->num_tx_ring - 4)) {

		if (!sh_eth_txfree(ndev)) {

		if (!sh_eth_tx_free(ndev, true)) {

			netif_warn(mdp, tx_queued, ndev, "TxFD exhausted.\n");

			netif_stop_queue(ndev);

			spin_unlock_irqrestore(&mdp->lock, flags);