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3c59x: fix missing dma_mapping_error check and bad ring refill logic
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A few spots in 3c59x missed calls to dma_mapping_error checks, casuing
WARN_ONS to trigger.  Clean those up.  While we're at it, refactor the
refill code a bit so that if skb allocation or dma mapping fails, we
recycle the existing buffer.  This prevents holes in the rx ring, and
makes for much simpler logic

Note: This is compile only tested.  Ted, if you could run this and
confirm that it continues to work properly, I would appreciate it, as I
currently don't have access to this hardware

Signed-off-by: Neil Horman <nhorman@redhat.com>
CC: Steffen Klassert <klassert@mathematik.tu-chemnitz.de>
CC: "David S. Miller" <davem@davemloft.net>
Reported-by: tedheadster@gmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
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Neil Horman authored and David S. Miller committed Jan 3, 2018
1 parent 74c88af commit ee4aa8d
Showing 1 changed file with 38 additions and 52 deletions.
90 changes: 38 additions & 52 deletions drivers/net/ethernet/3com/3c59x.c
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Original file line number Diff line number Diff line change
Expand Up @@ -602,7 +602,7 @@ struct vortex_private {
struct sk_buff* rx_skbuff[RX_RING_SIZE];
struct sk_buff* tx_skbuff[TX_RING_SIZE];
unsigned int cur_rx, cur_tx; /* The next free ring entry */
unsigned int dirty_rx, dirty_tx; /* The ring entries to be free()ed. */
unsigned int dirty_tx; /* The ring entries to be free()ed. */
struct vortex_extra_stats xstats; /* NIC-specific extra stats */
struct sk_buff *tx_skb; /* Packet being eaten by bus master ctrl. */
dma_addr_t tx_skb_dma; /* Allocated DMA address for bus master ctrl DMA. */
Expand All @@ -618,7 +618,6 @@ struct vortex_private {

/* The remainder are related to chip state, mostly media selection. */
struct timer_list timer; /* Media selection timer. */
struct timer_list rx_oom_timer; /* Rx skb allocation retry timer */
int options; /* User-settable misc. driver options. */
unsigned int media_override:4, /* Passed-in media type. */
default_media:4, /* Read from the EEPROM/Wn3_Config. */
Expand Down Expand Up @@ -760,7 +759,6 @@ static void mdio_sync(struct vortex_private *vp, int bits);
static int mdio_read(struct net_device *dev, int phy_id, int location);
static void mdio_write(struct net_device *vp, int phy_id, int location, int value);
static void vortex_timer(struct timer_list *t);
static void rx_oom_timer(struct timer_list *t);
static netdev_tx_t vortex_start_xmit(struct sk_buff *skb,
struct net_device *dev);
static netdev_tx_t boomerang_start_xmit(struct sk_buff *skb,
Expand Down Expand Up @@ -1601,7 +1599,6 @@ vortex_up(struct net_device *dev)

timer_setup(&vp->timer, vortex_timer, 0);
mod_timer(&vp->timer, RUN_AT(media_tbl[dev->if_port].wait));
timer_setup(&vp->rx_oom_timer, rx_oom_timer, 0);

if (vortex_debug > 1)
pr_debug("%s: Initial media type %s.\n",
Expand Down Expand Up @@ -1676,7 +1673,7 @@ vortex_up(struct net_device *dev)
window_write16(vp, 0x0040, 4, Wn4_NetDiag);

if (vp->full_bus_master_rx) { /* Boomerang bus master. */
vp->cur_rx = vp->dirty_rx = 0;
vp->cur_rx = 0;
/* Initialize the RxEarly register as recommended. */
iowrite16(SetRxThreshold + (1536>>2), ioaddr + EL3_CMD);
iowrite32(0x0020, ioaddr + PktStatus);
Expand Down Expand Up @@ -1729,6 +1726,7 @@ vortex_open(struct net_device *dev)
struct vortex_private *vp = netdev_priv(dev);
int i;
int retval;
dma_addr_t dma;

/* Use the now-standard shared IRQ implementation. */
if ((retval = request_irq(dev->irq, vp->full_bus_master_rx ?
Expand All @@ -1753,7 +1751,11 @@ vortex_open(struct net_device *dev)
break; /* Bad news! */

skb_reserve(skb, NET_IP_ALIGN); /* Align IP on 16 byte boundaries */
vp->rx_ring[i].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data, PKT_BUF_SZ, PCI_DMA_FROMDEVICE));
dma = pci_map_single(VORTEX_PCI(vp), skb->data,
PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
if (dma_mapping_error(&VORTEX_PCI(vp)->dev, dma))
break;
vp->rx_ring[i].addr = cpu_to_le32(dma);
}
if (i != RX_RING_SIZE) {
pr_emerg("%s: no memory for rx ring\n", dev->name);
Expand Down Expand Up @@ -2067,6 +2069,12 @@ vortex_start_xmit(struct sk_buff *skb, struct net_device *dev)
int len = (skb->len + 3) & ~3;
vp->tx_skb_dma = pci_map_single(VORTEX_PCI(vp), skb->data, len,
PCI_DMA_TODEVICE);
if (dma_mapping_error(&VORTEX_PCI(vp)->dev, vp->tx_skb_dma)) {
dev_kfree_skb_any(skb);
dev->stats.tx_dropped++;
return NETDEV_TX_OK;
}

spin_lock_irq(&vp->window_lock);
window_set(vp, 7);
iowrite32(vp->tx_skb_dma, ioaddr + Wn7_MasterAddr);
Expand Down Expand Up @@ -2593,7 +2601,7 @@ boomerang_rx(struct net_device *dev)
int entry = vp->cur_rx % RX_RING_SIZE;
void __iomem *ioaddr = vp->ioaddr;
int rx_status;
int rx_work_limit = vp->dirty_rx + RX_RING_SIZE - vp->cur_rx;
int rx_work_limit = RX_RING_SIZE;

if (vortex_debug > 5)
pr_debug("boomerang_rx(): status %4.4x\n", ioread16(ioaddr+EL3_STATUS));
Expand All @@ -2614,7 +2622,8 @@ boomerang_rx(struct net_device *dev)
} else {
/* The packet length: up to 4.5K!. */
int pkt_len = rx_status & 0x1fff;
struct sk_buff *skb;
struct sk_buff *skb, *newskb;
dma_addr_t newdma;
dma_addr_t dma = le32_to_cpu(vp->rx_ring[entry].addr);

if (vortex_debug > 4)
Expand All @@ -2633,9 +2642,27 @@ boomerang_rx(struct net_device *dev)
pci_dma_sync_single_for_device(VORTEX_PCI(vp), dma, PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
vp->rx_copy++;
} else {
/* Pre-allocate the replacement skb. If it or its
* mapping fails then recycle the buffer thats already
* in place
*/
newskb = netdev_alloc_skb_ip_align(dev, PKT_BUF_SZ);
if (!newskb) {
dev->stats.rx_dropped++;
goto clear_complete;
}
newdma = pci_map_single(VORTEX_PCI(vp), newskb->data,
PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
if (dma_mapping_error(&VORTEX_PCI(vp)->dev, newdma)) {
dev->stats.rx_dropped++;
consume_skb(newskb);
goto clear_complete;
}

/* Pass up the skbuff already on the Rx ring. */
skb = vp->rx_skbuff[entry];
vp->rx_skbuff[entry] = NULL;
vp->rx_skbuff[entry] = newskb;
vp->rx_ring[entry].addr = cpu_to_le32(newdma);
skb_put(skb, pkt_len);
pci_unmap_single(VORTEX_PCI(vp), dma, PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
vp->rx_nocopy++;
Expand All @@ -2653,55 +2680,15 @@ boomerang_rx(struct net_device *dev)
netif_rx(skb);
dev->stats.rx_packets++;
}
entry = (++vp->cur_rx) % RX_RING_SIZE;
}
/* Refill the Rx ring buffers. */
for (; vp->cur_rx - vp->dirty_rx > 0; vp->dirty_rx++) {
struct sk_buff *skb;
entry = vp->dirty_rx % RX_RING_SIZE;
if (vp->rx_skbuff[entry] == NULL) {
skb = netdev_alloc_skb_ip_align(dev, PKT_BUF_SZ);
if (skb == NULL) {
static unsigned long last_jif;
if (time_after(jiffies, last_jif + 10 * HZ)) {
pr_warn("%s: memory shortage\n",
dev->name);
last_jif = jiffies;
}
if ((vp->cur_rx - vp->dirty_rx) == RX_RING_SIZE)
mod_timer(&vp->rx_oom_timer, RUN_AT(HZ * 1));
break; /* Bad news! */
}

vp->rx_ring[entry].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data, PKT_BUF_SZ, PCI_DMA_FROMDEVICE));
vp->rx_skbuff[entry] = skb;
}
clear_complete:
vp->rx_ring[entry].status = 0; /* Clear complete bit. */
iowrite16(UpUnstall, ioaddr + EL3_CMD);
entry = (++vp->cur_rx) % RX_RING_SIZE;
}
return 0;
}

/*
* If we've hit a total OOM refilling the Rx ring we poll once a second
* for some memory. Otherwise there is no way to restart the rx process.
*/
static void
rx_oom_timer(struct timer_list *t)
{
struct vortex_private *vp = from_timer(vp, t, rx_oom_timer);
struct net_device *dev = vp->mii.dev;

spin_lock_irq(&vp->lock);
if ((vp->cur_rx - vp->dirty_rx) == RX_RING_SIZE) /* This test is redundant, but makes me feel good */
boomerang_rx(dev);
if (vortex_debug > 1) {
pr_debug("%s: rx_oom_timer %s\n", dev->name,
((vp->cur_rx - vp->dirty_rx) != RX_RING_SIZE) ? "succeeded" : "retrying");
}
spin_unlock_irq(&vp->lock);
}

static void
vortex_down(struct net_device *dev, int final_down)
{
Expand All @@ -2711,7 +2698,6 @@ vortex_down(struct net_device *dev, int final_down)
netdev_reset_queue(dev);
netif_stop_queue(dev);

del_timer_sync(&vp->rx_oom_timer);
del_timer_sync(&vp->timer);

/* Turn off statistics ASAP. We update dev->stats below. */
Expand Down

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