ether.c

来自「omap3 linux 2.6 用nocc去除了冗余代码」· C语言 代码 · 共 2,360 行 · 第 1/5 页

}

static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p)
{
	struct eth_dev	*dev = netdev_priv(net);
	strlcpy(p->driver, shortname, sizeof p->driver);
	strlcpy(p->version, DRIVER_VERSION, sizeof p->version);
	strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version);
	strlcpy (p->bus_info, dev->gadget->dev.bus_id, sizeof p->bus_info);
}

static u32 eth_get_link(struct net_device *net)
{
	struct eth_dev	*dev = netdev_priv(net);
	return dev->gadget->speed != USB_SPEED_UNKNOWN;
}

static struct ethtool_ops ops = {
	.get_drvinfo = eth_get_drvinfo,
	.get_link = eth_get_link
};

static void defer_kevent (struct eth_dev *dev, int flag)
{
	if (test_and_set_bit (flag, &dev->todo))
		return;
	if (!schedule_work (&dev->work))
		ERROR (dev, "kevent %d may have been dropped\n", flag);
	else
		DEBUG (dev, "kevent %d scheduled\n", flag);
}

static void rx_complete (struct usb_ep *ep, struct usb_request *req);

static int
rx_submit (struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
{
	struct sk_buff		*skb;
	int			retval = -ENOMEM;
	size_t			size;

	/* 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 synch on their own.
	 */
	size = (sizeof (struct ethhdr) + dev->net->mtu + RX_EXTRA);
	size += dev->out_ep->maxpacket - 1;
	if (rndis_active(dev))
		size += sizeof (struct rndis_packet_msg_type);
	size -= size % dev->out_ep->maxpacket;

	if ((skb = alloc_skb (size + NET_IP_ALIGN, gfp_flags)) == 0) {
		DEBUG (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.
	 */
	skb_reserve(skb, NET_IP_ALIGN);

	req->buf = skb->data;
	req->length = size;
	req->complete = rx_complete;
	req->context = skb;

	retval = usb_ep_queue (dev->out_ep, req, gfp_flags);
	if (retval == -ENOMEM)
enomem:
		defer_kevent (dev, WORK_RX_MEMORY);
	if (retval) {
		DEBUG (dev, "rx submit --> %d\n", retval);
		if (skb)
			dev_kfree_skb_any(skb);
		spin_lock(&dev->req_lock);
		list_add (&req->list, &dev->rx_reqs);
		spin_unlock(&dev->req_lock);
	}
	return retval;
}

static void rx_complete (struct usb_ep *ep, struct usb_request *req)
{
	struct sk_buff	*skb = req->context;
	struct eth_dev	*dev = ep->driver_data;
	int		status = req->status;

	switch (status) {

	/* normal completion */
	case 0:
		skb_put (skb, req->actual);
		/* we know MaxPacketsPerTransfer == 1 here */
		if (rndis_active(dev))
			status = rndis_rm_hdr (skb);
		if (status < 0
				|| ETH_HLEN > skb->len
				|| skb->len > ETH_FRAME_LEN) {
			dev->stats.rx_errors++;
			dev->stats.rx_length_errors++;
			DEBUG (dev, "rx length %d\n", skb->len);
			break;
		}

		skb->protocol = eth_type_trans (skb, dev->net);
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += skb->len;

		/* no buffer copies needed, unless hardware can't
		 * use skb buffers.
		 */
		status = netif_rx (skb);
		skb = NULL;
		break;

	/* software-driven interface shutdown */
	case -ECONNRESET:		// unlink
	case -ESHUTDOWN:		// disconnect etc
		VDEBUG (dev, "rx shutdown, code %d\n", status);
		goto quiesce;

	/* for hardware automagic (such as pxa) */
	case -ECONNABORTED:		// endpoint reset
		DEBUG (dev, "rx %s reset\n", ep->name);
		defer_kevent (dev, WORK_RX_MEMORY);
quiesce:
		dev_kfree_skb_any (skb);
		goto clean;

	/* data overrun */
	case -EOVERFLOW:
		dev->stats.rx_over_errors++;
		// FALLTHROUGH

	default:
		dev->stats.rx_errors++;
		DEBUG (dev, "rx status %d\n", status);
		break;
	}

	if (skb)
		dev_kfree_skb_any (skb);
	if (!netif_running (dev->net)) {
clean:
		spin_lock(&dev->req_lock);
		list_add (&req->list, &dev->rx_reqs);
		spin_unlock(&dev->req_lock);
		req = NULL;
	}
	if (req)
		rx_submit (dev, req, GFP_ATOMIC);
}

static int prealloc (struct list_head *list, struct usb_ep *ep,
			unsigned n, gfp_t gfp_flags)
{
	unsigned		i;
	struct usb_request	*req;

	if (!n)
		return -ENOMEM;

	/* queue/recycle up to N requests */
	i = n;
	list_for_each_entry (req, list, list) {
		if (i-- == 0)
			goto extra;
	}
	while (i--) {
		req = usb_ep_alloc_request (ep, gfp_flags);
		if (!req)
			return list_empty (list) ? -ENOMEM : 0;
		list_add (&req->list, list);
	}
	return 0;

extra:
	/* free extras */
	for (;;) {
		struct list_head	*next;

		next = req->list.next;
		list_del (&req->list);
		usb_ep_free_request (ep, req);

		if (next == list)
			break;

		req = container_of (next, struct usb_request, list);
	}
	return 0;
}

static int alloc_requests (struct eth_dev *dev, unsigned n, gfp_t gfp_flags)
{
	int status;

	spin_lock(&dev->req_lock);
	status = prealloc (&dev->tx_reqs, dev->in_ep, n, gfp_flags);
	if (status < 0)
		goto fail;
	status = prealloc (&dev->rx_reqs, dev->out_ep, n, gfp_flags);
	if (status < 0)
		goto fail;
	goto done;
fail:
	DEBUG (dev, "can't alloc requests\n");
done:
	spin_unlock(&dev->req_lock);
	return status;
}

static void rx_fill (struct eth_dev *dev, gfp_t gfp_flags)
{
	struct usb_request	*req;
	unsigned long		flags;

	/* fill unused rxq slots with some skb */
	spin_lock_irqsave(&dev->req_lock, flags);
	while (!list_empty (&dev->rx_reqs)) {
		req = container_of (dev->rx_reqs.next,
				struct usb_request, list);
		list_del_init (&req->list);
		spin_unlock_irqrestore(&dev->req_lock, flags);

		if (rx_submit (dev, req, gfp_flags) < 0) {
			defer_kevent (dev, WORK_RX_MEMORY);
			return;
		}

		spin_lock_irqsave(&dev->req_lock, flags);
	}
	spin_unlock_irqrestore(&dev->req_lock, flags);
}

static void eth_work (struct work_struct *work)
{
	struct eth_dev	*dev = container_of(work, struct eth_dev, work);

	if (test_and_clear_bit (WORK_RX_MEMORY, &dev->todo)) {
		if (netif_running (dev->net))
			rx_fill (dev, GFP_KERNEL);
	}

	if (dev->todo)
		DEBUG (dev, "work done, flags = 0x%lx\n", dev->todo);
}

static void tx_complete (struct usb_ep *ep, struct usb_request *req)
{
	struct sk_buff	*skb = req->context;
	struct eth_dev	*dev = ep->driver_data;

	switch (req->status) {
	default:
		dev->stats.tx_errors++;
		VDEBUG (dev, "tx err %d\n", req->status);
		/* FALLTHROUGH */
	case -ECONNRESET:		// unlink
	case -ESHUTDOWN:		// disconnect etc
		break;
	case 0:
		dev->stats.tx_bytes += skb->len;
	}
	dev->stats.tx_packets++;

	spin_lock(&dev->req_lock);
	list_add (&req->list, &dev->tx_reqs);
	spin_unlock(&dev->req_lock);
	dev_kfree_skb_any (skb);

	atomic_dec (&dev->tx_qlen);
	if (netif_carrier_ok (dev->net))
		netif_wake_queue (dev->net);
}

static inline int eth_is_promisc (struct eth_dev *dev)
{
	/* no filters for the CDC subset; always promisc */
	if (subset_active (dev))
		return 1;
	return dev->cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS;
}

static int eth_start_xmit (struct sk_buff *skb, struct net_device *net)
{
	struct eth_dev		*dev = netdev_priv(net);
	int			length = skb->len;
	int			retval;
	struct usb_request	*req = NULL;
	unsigned long		flags;

	/* apply outgoing CDC or RNDIS filters */
	if (!eth_is_promisc (dev)) {
		u8		*dest = skb->data;

		if (is_multicast_ether_addr(dest)) {
			u16	type;

			/* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
			 * SET_ETHERNET_MULTICAST_FILTERS requests
			 */
			if (is_broadcast_ether_addr(dest))
				type = USB_CDC_PACKET_TYPE_BROADCAST;
			else
				type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
			if (!(dev->cdc_filter & type)) {
				dev_kfree_skb_any (skb);
				return 0;
			}
		}
		/* ignores USB_CDC_PACKET_TYPE_DIRECTED */
	}

	spin_lock_irqsave(&dev->req_lock, flags);
	req = container_of (dev->tx_reqs.next, struct usb_request, list);
	list_del (&req->list);
	if (list_empty (&dev->tx_reqs))
		netif_stop_queue (net);
	spin_unlock_irqrestore(&dev->req_lock, flags);

	/* no buffer copies needed, unless the network stack did it
	 * or the hardware can't use skb buffers.
	 * or there's not enough space for any RNDIS headers we need
	 */
	if (rndis_active(dev)) {
		struct sk_buff	*skb_rndis;

		skb_rndis = skb_realloc_headroom (skb,
				sizeof (struct rndis_packet_msg_type));
		if (!skb_rndis)
			goto drop;

		dev_kfree_skb_any (skb);
		skb = skb_rndis;
		rndis_add_hdr (skb);
		length = skb->len;
	}
	req->buf = skb->data;
	req->context = skb;
	req->complete = tx_complete;

	/* use zlp framing on tx for strict CDC-Ether conformance,
	 * though any robust network rx path ignores extra padding.
	 * and some hardware doesn't like to write zlps.
	 */
	req->zero = 1;
	if (!dev->zlp && (length % dev->in_ep->maxpacket) == 0)
		length++;

	req->length = length;

	/* throttle highspeed IRQ rate back slightly */
	req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH)
		? ((atomic_read (&dev->tx_qlen) % TX_DELAY) != 0)
		: 0;

	retval = usb_ep_queue (dev->in_ep, req, GFP_ATOMIC);
	switch (retval) {
	default:
		DEBUG (dev, "tx queue err %d\n", retval);
		break;
	case 0:
		net->trans_start = jiffies;
		atomic_inc (&dev->tx_qlen);
	}

	if (retval) {
drop:
		dev->stats.tx_dropped++;
		dev_kfree_skb_any (skb);
		spin_lock_irqsave(&dev->req_lock, flags);
		if (list_empty (&dev->tx_reqs))
			netif_start_queue (net);
		list_add (&req->list, &dev->tx_reqs);
		spin_unlock_irqrestore(&dev->req_lock, flags);
	}
	return 0;
}

/*-------------------------------------------------------------------------*/


/* The interrupt endpoint is used in RNDIS to notify the host when messages
 * other than data packets are available ... notably the REMOTE_NDIS_*_CMPLT
 * messages, but also REMOTE_NDIS_INDICATE_STATUS_MSG and potentially even
 * REMOTE_NDIS_KEEPALIVE_MSG.
 *
 * The RNDIS control queue is processed by GET_ENCAPSULATED_RESPONSE, and
 * normally just one notification will be queued.
 */

static struct usb_request *eth_req_alloc (struct usb_ep *, unsigned, gfp_t);
static void eth_req_free (struct usb_ep *ep, struct usb_request *req);

static void
rndis_control_ack_complete (struct usb_ep *ep, struct usb_request *req)
{
	struct eth_dev          *dev = ep->driver_data;

	if (req->status || req->actual != req->length)
		DEBUG (dev,
			"rndis control ack complete --> %d, %d/%d\n",
			req->status, req->actual, req->length);
	req->context = NULL;

	if (req != dev->stat_req)
		eth_req_free(ep, req);
}

static int rndis_control_ack (struct net_device *net)
{
	struct eth_dev          *dev = netdev_priv(net);
	int                     length;
	struct usb_request      *resp = dev->stat_req;

	/* in case RNDIS calls this after disconnect */
	if (!dev->status) {
		DEBUG (dev, "status ENODEV\n");
		return -ENODEV;
	}

	/* in case queue length > 1 */
	if (resp->context) {
		resp = eth_req_alloc (dev->status_ep, 8, GFP_ATOMIC);
		if (!resp)
			return -ENOMEM;
	}

	/* Send RNDIS RESPONSE_AVAILABLE notification;
	 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE should work too
	 */
	resp->length = 8;
	resp->complete = rndis_control_ack_complete;
	resp->context = dev;

	*((__le32 *) resp->buf) = __constant_cpu_to_le32 (1);
	*((__le32 *) resp->buf + 1) = __constant_cpu_to_le32 (0);

	length = usb_ep_queue (dev->status_ep, resp, GFP_ATOMIC);
	if (length < 0) {
		resp->status = 0;
		rndis_control_ack_complete (dev->status_ep, resp);
	}

	return 0;
}


static void eth_start (struct eth_dev *dev, gfp_t gfp_flags)
{
	DEBUG (dev, "%s\n", __FUNCTION__);

	/* fill the rx queue */
	rx_fill (dev, gfp_flags);

	/* and open the tx floodgates */
	atomic_set (&dev->tx_qlen, 0);
	netif_wake_queue (dev->net);
	if (rndis_active(dev)) {
		rndis_set_param_medium (dev->rndis_config,
					NDIS_MEDIUM_802_3,
					BITRATE(dev->gadget)/100);
		(void) rndis_signal_connect (dev->rndis_config);