ps3_gelic_net.c

来自「linux 内核源代码」· C语言 代码 · 共 1,580 行 · 第 1/3 页

 *
 * gelic_net_disable_txdmac terminates processing on the DMA controller by
 * turing off DMA and issueing a force end
 */
static inline void gelic_net_disable_txdmac(struct gelic_net_card *card)
{
	int status;

	/* this hvc blocks until the DMA in progress really stopped */
	status = lv1_net_stop_tx_dma(bus_id(card), dev_id(card), 0);
	if (status)
		dev_err(ctodev(card),
			"lv1_net_stop_tx_dma faild, status=%d\n", status);
}

/**
 * gelic_net_stop - called upon ifconfig down
 * @netdev: interface device structure
 *
 * always returns 0
 */
static int gelic_net_stop(struct net_device *netdev)
{
	struct gelic_net_card *card = netdev_priv(netdev);

	napi_disable(&card->napi);
	netif_stop_queue(netdev);

	/* turn off DMA, force end */
	gelic_net_disable_rxdmac(card);
	gelic_net_disable_txdmac(card);

	gelic_net_set_irq_mask(card, 0);

	/* disconnect event port */
	free_irq(card->netdev->irq, card->netdev);
	ps3_sb_event_receive_port_destroy(card->dev, card->netdev->irq);
	card->netdev->irq = NO_IRQ;

	netif_carrier_off(netdev);

	/* release chains */
	gelic_net_release_tx_chain(card, 1);
	gelic_net_release_rx_chain(card);

	gelic_net_free_chain(card, card->tx_top);
	gelic_net_free_chain(card, card->rx_top);

	return 0;
}

/**
 * gelic_net_get_next_tx_descr - returns the next available tx descriptor
 * @card: device structure to get descriptor from
 *
 * returns the address of the next descriptor, or NULL if not available.
 */
static struct gelic_net_descr *
gelic_net_get_next_tx_descr(struct gelic_net_card *card)
{
	if (!card->tx_chain.head)
		return NULL;
	/*  see if the next descriptor is free */
	if (card->tx_chain.tail != card->tx_chain.head->next &&
	    gelic_net_get_descr_status(card->tx_chain.head) ==
	    GELIC_NET_DESCR_NOT_IN_USE)
		return card->tx_chain.head;
	else
		return NULL;

}

/**
 * gelic_net_set_txdescr_cmdstat - sets the tx descriptor command field
 * @descr: descriptor structure to fill out
 * @skb: packet to consider
 *
 * fills out the command and status field of the descriptor structure,
 * depending on hardware checksum settings. This function assumes a wmb()
 * has executed before.
 */
static void gelic_net_set_txdescr_cmdstat(struct gelic_net_descr *descr,
					  struct sk_buff *skb)
{
	if (skb->ip_summed != CHECKSUM_PARTIAL)
		descr->dmac_cmd_status = GELIC_NET_DMAC_CMDSTAT_NOCS |
			GELIC_NET_DMAC_CMDSTAT_END_FRAME;
	else {
		/* is packet ip?
		 * if yes: tcp? udp? */
		if (skb->protocol == htons(ETH_P_IP)) {
			if (ip_hdr(skb)->protocol == IPPROTO_TCP)
				descr->dmac_cmd_status =
					GELIC_NET_DMAC_CMDSTAT_TCPCS |
					GELIC_NET_DMAC_CMDSTAT_END_FRAME;

			else if (ip_hdr(skb)->protocol == IPPROTO_UDP)
				descr->dmac_cmd_status =
					GELIC_NET_DMAC_CMDSTAT_UDPCS |
					GELIC_NET_DMAC_CMDSTAT_END_FRAME;
			else	/*
				 * the stack should checksum non-tcp and non-udp
				 * packets on his own: NETIF_F_IP_CSUM
				 */
				descr->dmac_cmd_status =
					GELIC_NET_DMAC_CMDSTAT_NOCS |
					GELIC_NET_DMAC_CMDSTAT_END_FRAME;
		}
	}
}

static inline struct sk_buff *gelic_put_vlan_tag(struct sk_buff *skb,
						 unsigned short tag)
{
	struct vlan_ethhdr *veth;
	static unsigned int c;

	if (skb_headroom(skb) < VLAN_HLEN) {
		struct sk_buff *sk_tmp = skb;
		pr_debug("%s: hd=%d c=%ud\n", __func__, skb_headroom(skb), c);
		skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
		if (!skb)
			return NULL;
		dev_kfree_skb_any(sk_tmp);
	}
	veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);

	/* Move the mac addresses to the top of buffer */
	memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);

	veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
	veth->h_vlan_TCI = htons(tag);

	return skb;
}

/**
 * gelic_net_prepare_tx_descr_v - get dma address of skb_data
 * @card: card structure
 * @descr: descriptor structure
 * @skb: packet to use
 *
 * returns 0 on success, <0 on failure.
 *
 */
static int gelic_net_prepare_tx_descr_v(struct gelic_net_card *card,
					struct gelic_net_descr *descr,
					struct sk_buff *skb)
{
	dma_addr_t buf;

	if (card->vlan_index != -1) {
		struct sk_buff *skb_tmp;
		skb_tmp = gelic_put_vlan_tag(skb,
					     card->vlan_id[card->vlan_index]);
		if (!skb_tmp)
			return -ENOMEM;
		skb = skb_tmp;
	}

	buf = dma_map_single(ctodev(card), skb->data, skb->len, DMA_TO_DEVICE);

	if (!buf) {
		dev_err(ctodev(card),
			"dma map 2 failed (%p, %i). Dropping packet\n",
			skb->data, skb->len);
		return -ENOMEM;
	}

	descr->buf_addr = buf;
	descr->buf_size = skb->len;
	descr->skb = skb;
	descr->data_status = 0;
	descr->next_descr_addr = 0; /* terminate hw descr */
	gelic_net_set_txdescr_cmdstat(descr, skb);

	/* bump free descriptor pointer */
	card->tx_chain.head = descr->next;
	return 0;
}

/**
 * gelic_net_kick_txdma - enables TX DMA processing
 * @card: card structure
 * @descr: descriptor address to enable TX processing at
 *
 */
static int gelic_net_kick_txdma(struct gelic_net_card *card,
				struct gelic_net_descr *descr)
{
	int status = 0;

	if (card->tx_dma_progress)
		return 0;

	if (gelic_net_get_descr_status(descr) == GELIC_NET_DESCR_CARDOWNED) {
		card->tx_dma_progress = 1;
		status = lv1_net_start_tx_dma(bus_id(card), dev_id(card),
					      descr->bus_addr, 0);
		if (status)
			dev_info(ctodev(card), "lv1_net_start_txdma failed," \
				 "status=%d\n", status);
	}
	return status;
}

/**
 * gelic_net_xmit - transmits a frame over the device
 * @skb: packet to send out
 * @netdev: interface device structure
 *
 * returns 0 on success, <0 on failure
 */
static int gelic_net_xmit(struct sk_buff *skb, struct net_device *netdev)
{
	struct gelic_net_card *card = netdev_priv(netdev);
	struct gelic_net_descr *descr;
	int result;
	unsigned long flags;

	spin_lock_irqsave(&card->tx_dma_lock, flags);

	gelic_net_release_tx_chain(card, 0);

	descr = gelic_net_get_next_tx_descr(card);
	if (!descr) {
		/*
		 * no more descriptors free
		 */
		netif_stop_queue(netdev);
		spin_unlock_irqrestore(&card->tx_dma_lock, flags);
		return NETDEV_TX_BUSY;
	}

	result = gelic_net_prepare_tx_descr_v(card, descr, skb);
	if (result) {
		/*
		 * DMA map failed.  As chanses are that failure
		 * would continue, just release skb and return
		 */
		card->netdev->stats.tx_dropped++;
		dev_kfree_skb_any(skb);
		spin_unlock_irqrestore(&card->tx_dma_lock, flags);
		return NETDEV_TX_OK;
	}
	/*
	 * link this prepared descriptor to previous one
	 * to achieve high performance
	 */
	descr->prev->next_descr_addr = descr->bus_addr;
	/*
	 * as hardware descriptor is modified in the above lines,
	 * ensure that the hardware sees it
	 */
	wmb();
	if (gelic_net_kick_txdma(card, descr)) {
		/*
		 * kick failed.
		 * release descriptors which were just prepared
		 */
		card->netdev->stats.tx_dropped++;
		gelic_net_release_tx_descr(card, descr);
		gelic_net_release_tx_descr(card, descr->next);
		card->tx_chain.tail = descr->next->next;
		dev_info(ctodev(card), "%s: kick failure\n", __func__);
	} else {
		/* OK, DMA started/reserved */
		netdev->trans_start = jiffies;
	}

	spin_unlock_irqrestore(&card->tx_dma_lock, flags);
	return NETDEV_TX_OK;
}

/**
 * gelic_net_pass_skb_up - takes an skb from a descriptor and passes it on
 * @descr: descriptor to process
 * @card: card structure
 *
 * iommu-unmaps the skb, fills out skb structure and passes the data to the
 * stack. The descriptor state is not changed.
 */
static void gelic_net_pass_skb_up(struct gelic_net_descr *descr,
				 struct gelic_net_card *card)
{
	struct sk_buff *skb;
	struct net_device *netdev;
	u32 data_status, data_error;

	data_status = descr->data_status;
	data_error = descr->data_error;
	netdev = card->netdev;
	/* unmap skb buffer */
	skb = descr->skb;
	dma_unmap_single(ctodev(card), descr->buf_addr, GELIC_NET_MAX_MTU,
			 DMA_FROM_DEVICE);

	skb_put(skb, descr->valid_size? descr->valid_size : descr->result_size);
	if (!descr->valid_size)
		dev_info(ctodev(card), "buffer full %x %x %x\n",
			 descr->result_size, descr->buf_size,
			 descr->dmac_cmd_status);

	descr->skb = NULL;
	/*
	 * the card put 2 bytes vlan tag in front
	 * of the ethernet frame
	 */
	skb_pull(skb, 2);
	skb->protocol = eth_type_trans(skb, netdev);

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

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

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

/**
 * gelic_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
 */
static int gelic_net_decode_one_descr(struct gelic_net_card *card)
{
	enum gelic_net_descr_status status;
	struct gelic_net_descr_chain *chain = &card->rx_chain;
	struct gelic_net_descr *descr = chain->tail;
	int dmac_chain_ended;

	status = gelic_net_get_descr_status(descr);
	/* is this descriptor terminated with next_descr == NULL? */
	dmac_chain_ended =
		descr->dmac_cmd_status & GELIC_NET_DMAC_CMDSTAT_RXDCEIS;

	if (status == GELIC_NET_DESCR_CARDOWNED)
		return 0;

	if (status == GELIC_NET_DESCR_NOT_IN_USE) {
		dev_dbg(ctodev(card), "dormant descr? %p\n", descr);
		return 0;
	}

	if ((status == GELIC_NET_DESCR_RESPONSE_ERROR) ||
	    (status == GELIC_NET_DESCR_PROTECTION_ERROR) ||
	    (status == GELIC_NET_DESCR_FORCE_END)) {
		dev_info(ctodev(card), "dropping RX descriptor with state %x\n",
			 status);
		card->netdev->stats.rx_dropped++;
		goto refill;
	}

	if (status == GELIC_NET_DESCR_BUFFER_FULL) {
		/*
		 * Buffer full would occur if and only if
		 * the frame length was longer than the size of this
		 * descriptor's buffer.  If the frame length was equal
		 * to or shorter than buffer'size, FRAME_END condition
		 * would occur.
		 * Anyway this frame was longer than the MTU,
		 * just drop it.
		 */
		dev_info(ctodev(card), "overlength frame\n");
		goto refill;
	}
	/*
	 * descriptoers any other than FRAME_END here should
	 * be treated as error.
	 */
	if (status != GELIC_NET_DESCR_FRAME_END) {
		dev_dbg(ctodev(card), "RX descriptor with state %x\n",
			status);
		goto refill;
	}

	/* ok, we've got a packet in descr */
	gelic_net_pass_skb_up(descr, card);
refill:
	/*
	 * So that always DMAC can see the end
	 * of the descriptor chain to avoid
	 * from unwanted DMAC overrun.
	 */
	descr->next_descr_addr = 0;

	/* change the descriptor state: */
	gelic_net_set_descr_status(descr, GELIC_NET_DESCR_NOT_IN_USE);

	/*
	 * this call can fail, but for now, just leave this
	 * decriptor without skb
	 */
	gelic_net_prepare_rx_descr(card, descr);

	chain->head = descr;
	chain->tail = descr->next;

	/*
	 * Set this descriptor the end of the chain.
	 */
	descr->prev->next_descr_addr = descr->bus_addr;

	/*
	 * If dmac chain was met, DMAC stopped.
	 * thus re-enable it
	 */
	if (dmac_chain_ended) {
		card->rx_dma_restart_required = 1;
		dev_dbg(ctodev(card), "reenable rx dma scheduled\n");
	}

	return 1;
}

/**
 * gelic_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.
 *
 */
static int gelic_net_poll(struct napi_struct *napi, int budget)
{
	struct gelic_net_card *card = container_of(napi, struct gelic_net_card, napi);
	struct net_device *netdev = card->netdev;
	int packets_done = 0;

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

		packets_done++;
	}

	if (packets_done < budget) {
		netif_rx_complete(netdev, napi);
		gelic_net_rx_irq_on(card);
	}
	return packets_done;
}
/**
 * gelic_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 gelic_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 < GELIC_NET_MIN_MTU) ||
	    (new_mtu > GELIC_NET_MAX_MTU)) {
		return -EINVAL;
	}
	netdev->mtu = new_mtu;
	return 0;
}

/**
 * gelic_net_interrupt - event handler for gelic_net
 */
static irqreturn_t gelic_net_interrupt(int irq, void *ptr)
{
	unsigned long flags;
	struct net_device *netdev = ptr;
	struct gelic_net_card *card = netdev_priv(netdev);
	u64 status;

	status = card->irq_status;

	if (!status)
		return IRQ_NONE;

	if (card->rx_dma_restart_required) {
		card->rx_dma_restart_required = 0;
		gelic_net_enable_rxdmac(card);
	}

	if (status & GELIC_NET_RXINT) {
		gelic_net_rx_irq_off(card);
		netif_rx_schedule(netdev, &card->napi);
	}

	if (status & GELIC_NET_TXINT) {
		spin_lock_irqsave(&card->tx_dma_lock, flags);
		card->tx_dma_progress = 0;
		gelic_net_release_tx_chain(card, 0);
		/* kick outstanding tx descriptor if any */
		gelic_net_kick_txdma(card, card->tx_chain.tail);
		spin_unlock_irqrestore(&card->tx_dma_lock, flags);
	}
	return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/**
 * gelic_net_poll_controller - artificial interrupt for netconsole etc.
 * @netdev: interface device structure
 *
 * see Documentation/networking/netconsole.txt
 */
static void gelic_net_poll_controller(struct net_device *netdev)
{
	struct gelic_net_card *card = netdev_priv(netdev);

	gelic_net_set_irq_mask(card, 0);
	gelic_net_interrupt(netdev->irq, netdev);
	gelic_net_set_irq_mask(card, card->ghiintmask);
}