spider_net.c

linux 内核源代码

 * packets, including updating the queue tail pointer.
 */
static void
spider_net_cleanup_tx_ring(struct spider_net_card *card)
{
	if ((spider_net_release_tx_chain(card, 0) != 0) &&
	    (card->netdev->flags & IFF_UP)) {
		spider_net_kick_tx_dma(card);
		netif_wake_queue(card->netdev);
	}
}

/**
 * spider_net_do_ioctl - called for device ioctls
 * @netdev: interface device structure
 * @ifr: request parameter structure for ioctl
 * @cmd: command code for ioctl
 *
 * returns 0 on success, <0 on failure. Currently, we have no special ioctls.
 * -EOPNOTSUPP is returned, if an unknown ioctl was requested
 */
static int
spider_net_do_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
{
	switch (cmd) {
	default:
		return -EOPNOTSUPP;
	}
}

/**
 * spider_net_pass_skb_up - takes an skb from a descriptor and passes it on
 * @descr: descriptor to process
 * @card: card structure
 *
 * Fills out skb structure and passes the data to the stack.
 * The descriptor state is not changed.
 */
static void
spider_net_pass_skb_up(struct spider_net_descr *descr,
		       struct spider_net_card *card)
{
	struct spider_net_hw_descr *hwdescr = descr->hwdescr;
	struct sk_buff *skb = descr->skb;
	struct net_device *netdev = card->netdev;
	u32 data_status = hwdescr->data_status;
	u32 data_error = hwdescr->data_error;

	skb_put(skb, hwdescr->valid_size);

	/* the card seems to add 2 bytes of junk in front
	 * of the ethernet frame */
#define SPIDER_MISALIGN		2
	skb_pull(skb, SPIDER_MISALIGN);
	skb->protocol = eth_type_trans(skb, netdev);

	/* checksum offload */
	if (card->options.rx_csum) {
		if ( ( (data_status & SPIDER_NET_DATA_STATUS_CKSUM_MASK) ==
		       SPIDER_NET_DATA_STATUS_CKSUM_MASK) &&
		     !(data_error & SPIDER_NET_DATA_ERR_CKSUM_MASK))
			skb->ip_summed = CHECKSUM_UNNECESSARY;
		else
			skb->ip_summed = CHECKSUM_NONE;
	} else
		skb->ip_summed = CHECKSUM_NONE;

	if (data_status & SPIDER_NET_VLAN_PACKET) {
		/* further enhancements: HW-accel VLAN
		 * vlan_hwaccel_receive_skb
		 */
	}

	/* update netdevice statistics */
	netdev->stats.rx_packets++;
	netdev->stats.rx_bytes += skb->len;

	/* pass skb up to stack */
	netif_receive_skb(skb);
}

static void show_rx_chain(struct spider_net_card *card)
{
	struct spider_net_descr_chain *chain = &card->rx_chain;
	struct spider_net_descr *start= chain->tail;
	struct spider_net_descr *descr= start;
	struct spider_net_hw_descr *hwd = start->hwdescr;
	struct device *dev = &card->netdev->dev;
	u32 curr_desc, next_desc;
	int status;

	int tot = 0;
	int cnt = 0;
	int off = start - chain->ring;
	int cstat = hwd->dmac_cmd_status;

	dev_info(dev, "Total number of descrs=%d\n",
		chain->num_desc);
	dev_info(dev, "Chain tail located at descr=%d, status=0x%x\n",
		off, cstat);

	curr_desc = spider_net_read_reg(card, SPIDER_NET_GDACTDPA);
	next_desc = spider_net_read_reg(card, SPIDER_NET_GDACNEXTDA);

	status = cstat;
	do
	{
		hwd = descr->hwdescr;
		off = descr - chain->ring;
		status = hwd->dmac_cmd_status;

		if (descr == chain->head)
			dev_info(dev, "Chain head is at %d, head status=0x%x\n",
			         off, status);

		if (curr_desc == descr->bus_addr)
			dev_info(dev, "HW curr desc (GDACTDPA) is at %d, status=0x%x\n",
			         off, status);

		if (next_desc == descr->bus_addr)
			dev_info(dev, "HW next desc (GDACNEXTDA) is at %d, status=0x%x\n",
			         off, status);

		if (hwd->next_descr_addr == 0)
			dev_info(dev, "chain is cut at %d\n", off);

		if (cstat != status) {
			int from = (chain->num_desc + off - cnt) % chain->num_desc;
			int to = (chain->num_desc + off - 1) % chain->num_desc;
			dev_info(dev, "Have %d (from %d to %d) descrs "
			         "with stat=0x%08x\n", cnt, from, to, cstat);
			cstat = status;
			cnt = 0;
		}

		cnt ++;
		tot ++;
		descr = descr->next;
	} while (descr != start);

	dev_info(dev, "Last %d descrs with stat=0x%08x "
	         "for a total of %d descrs\n", cnt, cstat, tot);

#ifdef DEBUG
	/* Now dump the whole ring */
	descr = start;
	do
	{
		struct spider_net_hw_descr *hwd = descr->hwdescr;
		status = spider_net_get_descr_status(hwd);
		cnt = descr - chain->ring;
		dev_info(dev, "Descr %d stat=0x%08x skb=%p\n",
		         cnt, status, descr->skb);
		dev_info(dev, "bus addr=%08x buf addr=%08x sz=%d\n",
		         descr->bus_addr, hwd->buf_addr, hwd->buf_size);
		dev_info(dev, "next=%08x result sz=%d valid sz=%d\n",
		         hwd->next_descr_addr, hwd->result_size,
		         hwd->valid_size);
		dev_info(dev, "dmac=%08x data stat=%08x data err=%08x\n",
		         hwd->dmac_cmd_status, hwd->data_status,
		         hwd->data_error);
		dev_info(dev, "\n");

		descr = descr->next;
	} while (descr != start);
#endif

}

/**
 * spider_net_resync_head_ptr - Advance head ptr past empty descrs
 *
 * If the driver fails to keep up and empty the queue, then the
 * hardware wil run out of room to put incoming packets. This
 * will cause the hardware to skip descrs that are full (instead
 * of halting/retrying). Thus, once the driver runs, it wil need
 * to "catch up" to where the hardware chain pointer is at.
 */
static void spider_net_resync_head_ptr(struct spider_net_card *card)
{
	unsigned long flags;
	struct spider_net_descr_chain *chain = &card->rx_chain;
	struct spider_net_descr *descr;
	int i, status;

	/* Advance head pointer past any empty descrs */
	descr = chain->head;
	status = spider_net_get_descr_status(descr->hwdescr);

	if (status == SPIDER_NET_DESCR_NOT_IN_USE)
		return;

	spin_lock_irqsave(&chain->lock, flags);

	descr = chain->head;
	status = spider_net_get_descr_status(descr->hwdescr);
	for (i=0; i<chain->num_desc; i++) {
		if (status != SPIDER_NET_DESCR_CARDOWNED) break;
		descr = descr->next;
		status = spider_net_get_descr_status(descr->hwdescr);
	}
	chain->head = descr;

	spin_unlock_irqrestore(&chain->lock, flags);
}

static int spider_net_resync_tail_ptr(struct spider_net_card *card)
{
	struct spider_net_descr_chain *chain = &card->rx_chain;
	struct spider_net_descr *descr;
	int i, status;

	/* Advance tail pointer past any empty and reaped descrs */
	descr = chain->tail;
	status = spider_net_get_descr_status(descr->hwdescr);

	for (i=0; i<chain->num_desc; i++) {
		if ((status != SPIDER_NET_DESCR_CARDOWNED) &&
		    (status != SPIDER_NET_DESCR_NOT_IN_USE)) break;
		descr = descr->next;
		status = spider_net_get_descr_status(descr->hwdescr);
	}
	chain->tail = descr;

	if ((i == chain->num_desc) || (i == 0))
		return 1;
	return 0;
}

/**
 * spider_net_decode_one_descr - processes an RX descriptor
 * @card: card structure
 *
 * Returns 1 if a packet has been sent to the stack, otherwise 0.
 *
 * Processes an RX descriptor by iommu-unmapping the data buffer
 * and passing the packet up to the stack. This function is called
 * in softirq context, e.g. either bottom half from interrupt or
 * NAPI polling context.
 */
static int
spider_net_decode_one_descr(struct spider_net_card *card)
{
	struct net_device *dev = card->netdev;
	struct spider_net_descr_chain *chain = &card->rx_chain;
	struct spider_net_descr *descr = chain->tail;
	struct spider_net_hw_descr *hwdescr = descr->hwdescr;
	u32 hw_buf_addr;
	int status;

	status = spider_net_get_descr_status(hwdescr);

	/* Nothing in the descriptor, or ring must be empty */
	if ((status == SPIDER_NET_DESCR_CARDOWNED) ||
	    (status == SPIDER_NET_DESCR_NOT_IN_USE))
		return 0;

	/* descriptor definitively used -- move on tail */
	chain->tail = descr->next;

	/* unmap descriptor */
	hw_buf_addr = hwdescr->buf_addr;
	hwdescr->buf_addr = 0xffffffff;
	pci_unmap_single(card->pdev, hw_buf_addr,
			SPIDER_NET_MAX_FRAME, PCI_DMA_FROMDEVICE);

	if ( (status == SPIDER_NET_DESCR_RESPONSE_ERROR) ||
	     (status == SPIDER_NET_DESCR_PROTECTION_ERROR) ||
	     (status == SPIDER_NET_DESCR_FORCE_END) ) {
		if (netif_msg_rx_err(card))
			dev_err(&dev->dev,
			       "dropping RX descriptor with state %d\n", status);
		dev->stats.rx_dropped++;
		goto bad_desc;
	}

	if ( (status != SPIDER_NET_DESCR_COMPLETE) &&
	     (status != SPIDER_NET_DESCR_FRAME_END) ) {
		if (netif_msg_rx_err(card))
			dev_err(&card->netdev->dev,
			       "RX descriptor with unknown state %d\n", status);
		card->spider_stats.rx_desc_unk_state++;
		goto bad_desc;
	}

	/* The cases we'll throw away the packet immediately */
	if (hwdescr->data_error & SPIDER_NET_DESTROY_RX_FLAGS) {
		if (netif_msg_rx_err(card))
			dev_err(&card->netdev->dev,
			       "error in received descriptor found, "
			       "data_status=x%08x, data_error=x%08x\n",
			       hwdescr->data_status, hwdescr->data_error);
		goto bad_desc;
	}

	if (hwdescr->dmac_cmd_status & SPIDER_NET_DESCR_BAD_STATUS) {
		dev_err(&card->netdev->dev, "bad status, cmd_status=x%08x\n",
			       hwdescr->dmac_cmd_status);
		pr_err("buf_addr=x%08x\n", hw_buf_addr);
		pr_err("buf_size=x%08x\n", hwdescr->buf_size);
		pr_err("next_descr_addr=x%08x\n", hwdescr->next_descr_addr);
		pr_err("result_size=x%08x\n", hwdescr->result_size);
		pr_err("valid_size=x%08x\n", hwdescr->valid_size);
		pr_err("data_status=x%08x\n", hwdescr->data_status);
		pr_err("data_error=x%08x\n", hwdescr->data_error);
		pr_err("which=%ld\n", descr - card->rx_chain.ring);

		card->spider_stats.rx_desc_error++;
		goto bad_desc;
	}

	/* Ok, we've got a packet in descr */
	spider_net_pass_skb_up(descr, card);
	descr->skb = NULL;
	hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
	return 1;

bad_desc:
	if (netif_msg_rx_err(card))
		show_rx_chain(card);
	dev_kfree_skb_irq(descr->skb);
	descr->skb = NULL;
	hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
	return 0;
}

/**
 * spider_net_poll - NAPI poll function called by the stack to return packets
 * @netdev: interface device structure
 * @budget: number of packets we can pass to the stack at most
 *
 * returns 0 if no more packets available to the driver/stack. Returns 1,
 * if the quota is exceeded, but the driver has still packets.
 *
 * spider_net_poll returns all packets from the rx descriptors to the stack
 * (using netif_receive_skb). If all/enough packets are up, the driver
 * reenables interrupts and returns 0. If not, 1 is returned.
 */
static int spider_net_poll(struct napi_struct *napi, int budget)
{
	struct spider_net_card *card = container_of(napi, struct spider_net_card, napi);
	struct net_device *netdev = card->netdev;
	int packets_done = 0;

	while (packets_done < budget) {
		if (!spider_net_decode_one_descr(card))
			break;

		packets_done++;
	}

	if ((packets_done == 0) && (card->num_rx_ints != 0)) {
		if (!spider_net_resync_tail_ptr(card))
			packets_done = budget;
		spider_net_resync_head_ptr(card);
	}
	card->num_rx_ints = 0;

	spider_net_refill_rx_chain(card);
	spider_net_enable_rxdmac(card);

	spider_net_cleanup_tx_ring(card);

	/* if all packets are in the stack, enable interrupts and return 0 */
	/* if not, return 1 */
	if (packets_done < budget) {
		netif_rx_complete(netdev, napi);
		spider_net_rx_irq_on(card);
		card->ignore_rx_ramfull = 0;
	}

	return packets_done;
}

/**
 * spider_net_change_mtu - changes the MTU of an interface
 * @netdev: interface device structure
 * @new_mtu: new MTU value
 *
 * returns 0 on success, <0 on failure
 */
static int
spider_net_change_mtu(struct net_device *netdev, int new_mtu)
{
	/* no need to re-alloc skbs or so -- the max mtu is about 2.3k
	 * and mtu is outbound only anyway */
	if ( (new_mtu < SPIDER_NET_MIN_MTU ) ||
		(new_mtu > SPIDER_NET_MAX_MTU) )
		return -EINVAL;
	netdev->mtu = new_mtu;
	return 0;
}

/**
 * spider_net_set_mac - sets the MAC of an interface
 * @netdev: interface device structure
 * @ptr: pointer to new MAC address
 *
 * Returns 0 on success, <0 on failure. Currently, we don't support this
 * and will always return EOPNOTSUPP.
 */
static int
spider_net_set_mac(struct net_device *netdev, void *p)
{
	struct spider_net_card *card = netdev_priv(netdev);
	u32 macl, macu, regvalue;
	struct sockaddr *addr = p;

	if (!is_valid_ether_addr(addr->sa_data))
		return -EADDRNOTAVAIL;

	/* switch off GMACTPE and GMACRPE */
	regvalue = spider_net_read_reg(card, SPIDER_NET_GMACOPEMD);
	regvalue &= ~((1 << 5) | (1 << 6));
	spider_net_write_reg(card, SPIDER_NET_GMACOPEMD, regvalue);

	/* write mac */
	macu = (addr->sa_data[0]<<24) + (addr->sa_data[1]<<16) +
		(addr->sa_data[2]<<8) + (addr->sa_data[3]);
	macl = (addr->sa_data[4]<<8) + (addr->sa_data[5]);
	spider_net_write_reg(card, SPIDER_NET_GMACUNIMACU, macu);
	spider_net_write_reg(card, SPIDER_NET_GMACUNIMACL, macl);

	/* switch GMACTPE and GMACRPE back on */
	regvalue = spider_net_read_reg(card, SPIDER_NET_GMACOPEMD);
	regvalue |= ((1 << 5) | (1 << 6));
	spider_net_write_reg(card, SPIDER_NET_GMACOPEMD, regvalue);

	spider_net_set_promisc(card);

	/* look up, whether we have been successful */
	if (spider_net_get_mac_address(netdev))
		return -EADDRNOTAVAIL;
	if (memcmp(netdev->dev_addr,addr->sa_data,netdev->addr_len))
		return -EADDRNOTAVAIL;

	return 0;
}

/**
 * spider_net_link_reset
 * @netdev: net device structure
 *
 * This is called when the PHY_LINK signal is asserted. For the blade this is
 * not connected so we should never get here.
 *
 */
static void
spider_net_link_reset(struct net_device *netdev)
{

	struct spider_net_card *card = netdev_priv(netdev);

	del_timer_sync(&card->aneg_timer);

	/* clear interrupt, block further interrupts */
	spider_net_write_reg(card, SPIDER_NET_GMACST,
			     spider_net_read_reg(card, SPIDER_NET_GMACST));
	spider_net_write_reg(card, SPIDER_NET_GMACINTEN, 0);

	/* reset phy and setup aneg */
	spider_net_setup_aneg(card);
	mod_timer(&card->aneg_timer, jiffies + SPIDER_NET_ANEG_TIMER);

}

/**
 * spider_net_handle_error_irq - handles errors raised by an interrupt
 * @card: card structure
 * @status_reg: interrupt status register 0 (GHIINT0STS)