Skip to content

Commit

Permalink
sh_eth: unmap DMA buffers when freeing rings
Browse files Browse the repository at this point in the history 
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 a47b70e ("ravb: unmap descriptors when freeing
rings").

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
@davem330
Sergei Shtylyov authored and davem330 committed Apr 19, 2017
1 parent 005882e commit 1debdc8
Showing 1 changed file with 67 additions and 55 deletions.
122 changes: 67 additions & 55 deletions drivers/net/ethernet/renesas/sh_eth.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1127,12 +1127,70 @@ static struct mdiobb_ops bb_ops = {
.get_mdio_data = sh_get_mdio,
};

/* 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);
struct sh_eth_txdesc *txdesc;
int free_num = 0;
int entry;
bool sent;

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++;
}
txdesc->status = cpu_to_le32(TD_TFP);
if (entry >= mdp->num_tx_ring - 1)
txdesc->status |= cpu_to_le32(TD_TDLE);

if (sent) {
ndev->stats.tx_packets++;
ndev->stats.tx_bytes += le32_to_cpu(txdesc->len) >> 16;
}
}
return free_num;
}

/* 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++)
Expand All @@ -1141,27 +1199,18 @@ static void sh_eth_ring_free(struct net_device *ndev)
kfree(mdp->rx_skbuff);
mdp->rx_skbuff = NULL;

/* Free Tx skb ringbuffer */
if (mdp->tx_skbuff) {
for (i = 0; i < mdp->num_tx_ring; i++)
dev_kfree_skb(mdp->tx_skbuff[i]);
}
kfree(mdp->tx_skbuff);
mdp->tx_skbuff = NULL;

if (mdp->rx_ring) {
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;
}

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 */
Expand Down Expand Up @@ -1409,43 +1458,6 @@ 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)
{
Expand Down Expand Up @@ -1690,7 +1702,7 @@ 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)) {
Expand Down Expand Up @@ -1751,7 +1763,7 @@ 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);
}

Expand Down Expand Up @@ -2412,7 +2424,7 @@ 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);
Expand Down

0 comments on commit 1debdc8

Please sign in to comment.