static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
{
struct sk_buff *skb;
struct skb_data *entry;
int retval = 0;
unsigned long lockflags;
size_t size = dev->rx_urb_size;
/* prevent rx skb allocation when error ratio is high */
if (test_bit(EVENT_RX_KILL, &dev->flags)) {
usb_free_urb(urb);
return -ENOLINK;
}
skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, flags);
if (NET_IP_ALIGN && skb)
skb_reserve(skb, NET_IP_ALIGN);
if (!skb) {
netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
usb_free_urb (urb);
return -ENOMEM;
}
entry = (struct skb_data *) skb->cb;
entry->urb = urb;
entry->dev = dev;
entry->length = 0;
usb_fill_bulk_urb (urb, dev->udev, dev->in,
skb->data, size, rx_complete, skb);
spin_lock_irqsave (&dev->rxq.lock, lockflags);
if (netif_running (dev->net) &&
netif_device_present (dev->net) &&
!test_bit (EVENT_RX_HALT, &dev->flags) &&
!test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
case -EPIPE:
usbnet_defer_kevent (dev, EVENT_RX_HALT);
break;
case -ENOMEM:
usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
break;
case -ENODEV:
netif_dbg(dev, ifdown, dev->net, "device gone\n");
netif_device_detach (dev->net);
break;
case -EHOSTUNREACH:
retval = -ENOLINK;
break;
default:
netif_dbg(dev, rx_err, dev->net,
"rx submit, %d\n", retval);
tasklet_schedule (&dev->bh);
break;
case 0:
__usbnet_queue_skb(&dev->rxq, skb, rx_start);
}
} else {
netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
retval = -ENOLINK;
}
spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
if (retval) {
dev_kfree_skb_any (skb);
usb_free_urb (urb);
}
return retval;
}
/*
* Kernel thread for USB reception of data
*
* This thread waits for a kick; once kicked, it will allocate an skb
* and receive a single message to it from USB (using
* i2400mu_rx()). Once received, it is passed to the generic i2400m RX
* code for processing.
*
* When done processing, it runs some dirty statistics to verify if
* the last 100 messages received were smaller than half of the
* current RX buffer size. In that case, the RX buffer size is
* halved. This will helps lowering the pressure on the memory
* allocator.
*
* Hard errors force the thread to exit.
*/
static
int i2400mu_rxd(void *_i2400mu)
{
int result = 0;
struct i2400mu *i2400mu = _i2400mu;
struct i2400m *i2400m = &i2400mu->i2400m;
struct device *dev = &i2400mu->usb_iface->dev;
struct net_device *net_dev = i2400m->wimax_dev.net_dev;
size_t pending;
int rx_size;
struct sk_buff *rx_skb;
unsigned long flags;
d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
spin_lock_irqsave(&i2400m->rx_lock, flags);
BUG_ON(i2400mu->rx_kthread != NULL);
i2400mu->rx_kthread = current;
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
while (1) {
d_printf(2, dev, "RX: waiting for messages\n");
pending = 0;
wait_event_interruptible(
i2400mu->rx_wq,
(kthread_should_stop() /* check this first! */
|| (pending = atomic_read(&i2400mu->rx_pending_count)))
);
if (kthread_should_stop())
break;
if (pending == 0)
continue;
rx_size = i2400mu->rx_size;
d_printf(2, dev, "RX: reading up to %d bytes\n", rx_size);
rx_skb = __netdev_alloc_skb(net_dev, rx_size, GFP_KERNEL);
if (rx_skb == NULL) {
dev_err(dev, "RX: can't allocate skb [%d bytes]\n",
rx_size);
msleep(50); /* give it some time? */
continue;
}
/* Receive the message with the payloads */
rx_skb = i2400mu_rx(i2400mu, rx_skb);
result = PTR_ERR(rx_skb);
if (IS_ERR(rx_skb))
goto out;
atomic_dec(&i2400mu->rx_pending_count);
if (rx_skb == NULL || rx_skb->len == 0) {
/* some "ignorable" condition */
kfree_skb(rx_skb);
continue;
}
/* Deliver the message to the generic i2400m code */
i2400mu->rx_size_cnt++;
i2400mu->rx_size_acc += rx_skb->len;
result = i2400m_rx(i2400m, rx_skb);
if (result == -EIO
&& edc_inc(&i2400mu->urb_edc,
EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
goto error_reset;
}
/* Maybe adjust RX buffer size */
i2400mu_rx_size_maybe_shrink(i2400mu);
}
result = 0;
out:
spin_lock_irqsave(&i2400m->rx_lock, flags);
i2400mu->rx_kthread = NULL;
spin_unlock_irqrestore(&i2400m->rx_lock, flags);
d_fnend(4, dev, "(i2400mu %p) = %d\n", i2400mu, result);
return result;
error_reset:
dev_err(dev, "RX: maximum errors in received buffer exceeded; "
"resetting device\n");
usb_queue_reset_device(i2400mu->usb_iface);
goto out;
}
static void xennet_alloc_rx_buffers(struct net_device *dev)
{
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;
struct page *page;
int i, batch_target, notify;
RING_IDX req_prod = np->rx.req_prod_pvt;
grant_ref_t ref;
unsigned long pfn;
void *vaddr;
struct xen_netif_rx_request *req;
if (unlikely(!netif_carrier_ok(dev)))
return;
/*
* Allocate skbuffs greedily, even though we batch updates to the
* receive ring. This creates a less bursty demand on the memory
* allocator, so should reduce the chance of failed allocation requests
* both for ourself and for other kernel subsystems.
*/
batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!skb))
goto no_skb;
/* Align ip header to a 16 bytes boundary */
skb_reserve(skb, NET_IP_ALIGN);
page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
if (!page) {
kfree_skb(skb);
no_skb:
/* Any skbuffs queued for refill? Force them out. */
if (i != 0)
goto refill;
/* Could not allocate any skbuffs. Try again later. */
mod_timer(&np->rx_refill_timer,
jiffies + (HZ/10));
break;
}
skb_shinfo(skb)->frags[0].page = page;
skb_shinfo(skb)->nr_frags = 1;
__skb_queue_tail(&np->rx_batch, skb);
}
/* Is the batch large enough to be worthwhile? */
if (i < (np->rx_target/2)) {
if (req_prod > np->rx.sring->req_prod)
goto push;
return;
}
/* Adjust our fill target if we risked running out of buffers. */
if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
((np->rx_target *= 2) > np->rx_max_target))
np->rx_target = np->rx_max_target;
refill:
for (i = 0; ; i++) {
skb = __skb_dequeue(&np->rx_batch);
if (skb == NULL)
break;
skb->dev = dev;
id = xennet_rxidx(req_prod + i);
BUG_ON(np->rx_skbs[id]);
np->rx_skbs[id] = skb;
ref = gnttab_claim_grant_reference(&np->gref_rx_head);
BUG_ON((signed short)ref < 0);
np->grant_rx_ref[id] = ref;
pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page);
vaddr = page_address(skb_shinfo(skb)->frags[0].page);
req = RING_GET_REQUEST(&np->rx, req_prod + i);
gnttab_grant_foreign_access_ref(ref,
np->xbdev->otherend_id,
pfn_to_mfn(pfn),
0);
req->id = id;
req->gref = ref;
}
wmb(); /* barrier so backend seens requests */
/* Above is a suitable barrier to ensure backend will see requests. */
np->rx.req_prod_pvt = req_prod + i;
push:
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
if (notify)
notify_remote_via_irq(np->netdev->irq);
}
static int
rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
{
struct usb_gadget *g = dev->gadget;
struct sk_buff *skb;
int retval = -ENOMEM;
size_t size = 0;
struct usb_ep *out;
unsigned long flags;
spin_lock_irqsave(&dev->lock, flags);
if (dev->port_usb)
out = dev->port_usb->out_ep;
else
out = NULL;
spin_unlock_irqrestore(&dev->lock, flags);
if (!out)
return -ENOTCONN;
/* Padding up to RX_EXTRA handles minor disagreements with host.
* Normally we use the USB "terminate on short read" convention;
* so allow up to (N*maxpacket), since that memory is normally
* already allocated. Some hardware doesn't deal well with short
* reads (e.g. DMA must be N*maxpacket), so for now don't trim a
* byte off the end (to force hardware errors on overflow).
*
* RNDIS uses internal framing, and explicitly allows senders to
* pad to end-of-packet. That's potentially nice for speed, but
* means receivers can't recover lost synch on their own (because
* new packets don't only start after a short RX).
*/
size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA;
size += dev->port_usb->header_len;
if (g->quirk_ep_out_aligned_size) {
size += out->maxpacket - 1;
size -= size % out->maxpacket;
}
if (dev->port_usb->is_fixed)
size = max_t(size_t, size, dev->port_usb->fixed_out_len);
skb = __netdev_alloc_skb(dev->net, size + NET_IP_ALIGN, gfp_flags);
if (skb == NULL) {
DBG(dev, "no rx skb\n");
goto enomem;
}
/* Some platforms perform better when IP packets are aligned,
* but on at least one, checksumming fails otherwise. Note:
* RNDIS headers involve variable numbers of LE32 values.
*/
if (likely(!dev->no_skb_reserve))
skb_reserve(skb, NET_IP_ALIGN);
req->buf = skb->data;
req->length = size;
req->complete = rx_complete;
req->context = skb;
retval = usb_ep_queue(out, req, gfp_flags);
if (retval == -ENOMEM)
enomem:
defer_kevent(dev, WORK_RX_MEMORY);
if (retval) {
DBG(dev, "rx submit --> %d\n", retval);
if (skb)
dev_kfree_skb_any(skb);
spin_lock_irqsave(&dev->req_lock, flags);
list_add(&req->list, &dev->rx_reqs);
spin_unlock_irqrestore(&dev->req_lock, flags);
}
return retval;
}
