/**
 * gelic_net_release_tx_descr - processes a used tx descriptor
 * @card: card structure
 * @descr: descriptor to release
 *
 * releases a used tx descriptor (unmapping, freeing of skb)
 */
static void gelic_net_release_tx_descr(struct gelic_net_card *card,
			    struct gelic_net_descr *descr)
{
	struct sk_buff *skb;


	if (descr->data_status & (1 << GELIC_NET_TXDESC_TAIL)) {
		/* 2nd descriptor */
		skb = descr->skb;
		dma_unmap_single(ctodev(card), descr->buf_addr, skb->len,
				 DMA_TO_DEVICE);
		dev_kfree_skb_any(skb);
	} else {
		dma_unmap_single(ctodev(card), descr->buf_addr,
				 descr->buf_size, DMA_TO_DEVICE);
	}

	descr->buf_addr = 0;
	descr->buf_size = 0;
	descr->next_descr_addr = 0;
	descr->result_size = 0;
	descr->valid_size = 0;
	descr->data_status = 0;
	descr->data_error = 0;
	descr->skb = NULL;

	/* set descr status */
	gelic_net_set_descr_status(descr, GELIC_NET_DESCR_NOT_IN_USE);
}

/**
 * gelic_net_open_device - open device and map dma region
 * @card: card structure
 */
static int gelic_net_open_device(struct gelic_net_card *card)
{
	int result;

	result = ps3_sb_event_receive_port_setup(card->dev, PS3_BINDING_CPU_ANY,
		&card->netdev->irq);

	if (result) {
		dev_info(ctodev(card),
			 "%s:%d: gelic_net_open_device failed (%d)\n",
			 __func__, __LINE__, result);
		result = -EPERM;
		goto fail_alloc_irq;
	}

	result = request_irq(card->netdev->irq, gelic_net_interrupt,
			     IRQF_DISABLED, card->netdev->name, card->netdev);

	if (result) {
		dev_info(ctodev(card), "%s:%d: request_irq failed (%d)\n",
			__func__, __LINE__, result);
		goto fail_request_irq;
	}

	return 0;

fail_request_irq:
	ps3_sb_event_receive_port_destroy(card->dev, card->netdev->irq);
	card->netdev->irq = NO_IRQ;
fail_alloc_irq:
	return result;
}

/**
 * gelic_net_set_multi - sets multicast addresses and promisc flags
 * @netdev: interface device structure
 *
 * gelic_net_set_multi configures multicast addresses as needed for the
 * netdev interface. It also sets up multicast, allmulti and promisc
 * flags appropriately
 */
void gelic_net_set_multi(struct net_device *netdev)
{
	struct gelic_card *card = netdev_card(netdev);
	struct dev_mc_list *mc;
	unsigned int i;
	uint8_t *p;
	u64 addr;
	int status;

	/* clear all multicast address */
	status = lv1_net_remove_multicast_address(bus_id(card), dev_id(card),
						  0, 1);
	if (status)
		dev_err(ctodev(card),
			"lv1_net_remove_multicast_address failed %d\n",
			status);
	/* set broadcast address */
	status = lv1_net_add_multicast_address(bus_id(card), dev_id(card),
					       GELIC_NET_BROADCAST_ADDR, 0);
	if (status)
		dev_err(ctodev(card),
			"lv1_net_add_multicast_address failed, %d\n",
			status);

	if ((netdev->flags & IFF_ALLMULTI) ||
	    (netdev->mc_count > GELIC_NET_MC_COUNT_MAX)) {
		status = lv1_net_add_multicast_address(bus_id(card),
						       dev_id(card),
						       0, 1);
		if (status)
			dev_err(ctodev(card),
				"lv1_net_add_multicast_address failed, %d\n",
				status);
		return;
	}

	/* set multicast addresses */
	for (mc = netdev->mc_list; mc; mc = mc->next) {
		addr = 0;
		p = mc->dmi_addr;
		for (i = 0; i < ETH_ALEN; i++) {
			addr <<= 8;
			addr |= *p++;
		}
		status = lv1_net_add_multicast_address(bus_id(card),
						       dev_id(card),
						       addr, 0);
		if (status)
			dev_err(ctodev(card),
				"lv1_net_add_multicast_address failed, %d\n",
				status);
	}
}

/**
 * gelic_card_init_chain - links descriptor chain
 * @card: card structure
 * @chain: address of chain
 * @start_descr: address of descriptor array
 * @no: number of descriptors
 *
 * we manage a circular list that mirrors the hardware structure,
 * except that the hardware uses bus addresses.
 *
 * returns 0 on success, <0 on failure
 */
static int __devinit gelic_card_init_chain(struct gelic_card *card,
					   struct gelic_descr_chain *chain,
					   struct gelic_descr *start_descr,
					   int no)
{
	int i;
	struct gelic_descr *descr;

	descr = start_descr;
	memset(descr, 0, sizeof(*descr) * no);

	/* set up the hardware pointers in each descriptor */
	for (i = 0; i < no; i++, descr++) {
		gelic_descr_set_status(descr, GELIC_DESCR_DMA_NOT_IN_USE);
		descr->bus_addr =
			dma_map_single(ctodev(card), descr,
				       GELIC_DESCR_SIZE,
				       DMA_BIDIRECTIONAL);

		if (!descr->bus_addr)
			goto iommu_error;

		descr->next = descr + 1;
		descr->prev = descr - 1;
	}
	/* make them as ring */
	(descr - 1)->next = start_descr;
	start_descr->prev = (descr - 1);

	/* chain bus addr of hw descriptor */
	descr = start_descr;
	for (i = 0; i < no; i++, descr++) {
		descr->next_descr_addr = cpu_to_be32(descr->next->bus_addr);
	}

	chain->head = start_descr;
	chain->tail = start_descr;

	/* do not chain last hw descriptor */
	(descr - 1)->next_descr_addr = 0;

	return 0;

iommu_error:
	for (i--, descr--; 0 <= i; i--, descr--)
		if (descr->bus_addr)
			dma_unmap_single(ctodev(card), descr->bus_addr,
					 GELIC_DESCR_SIZE,
					 DMA_BIDIRECTIONAL);
	return -ENOMEM;
}

/**
 * gelic_net_open - called upon ifonfig up
 * @netdev: interface device structure
 *
 * returns 0 on success, <0 on failure
 *
 * gelic_net_open allocates all the descriptors and memory needed for
 * operation, sets up multicast list and enables interrupts
 */
int gelic_net_open(struct net_device *netdev)
{
	struct gelic_card *card = netdev_card(netdev);

	dev_dbg(ctodev(card), " -> %s %p\n", __func__, netdev);

	gelic_card_up(card);

	netif_start_queue(netdev);
	gelic_card_get_ether_port_status(card, 1);

	dev_dbg(ctodev(card), " <- %s\n", __func__);
	return 0;
}

/**
 * gelic_net_pass_skb_up - takes an skb from a descriptor and passes it on
 * @descr: descriptor to process
 * @card: card structure
 * @netdev: net_device structure to be passed packet
 *
 * 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_descr *descr,
				  struct gelic_card *card,
				  struct net_device *netdev)

{
	struct sk_buff *skb = descr->skb;
	u32 data_status, data_error;

	data_status = be32_to_cpu(descr->data_status);
	data_error = be32_to_cpu(descr->data_error);
	/* unmap skb buffer */
	dma_unmap_single(ctodev(card), be32_to_cpu(descr->buf_addr),
			 GELIC_NET_MAX_MTU,
			 DMA_FROM_DEVICE);

	skb_put(skb, be32_to_cpu(descr->valid_size)?
		be32_to_cpu(descr->valid_size) :
		be32_to_cpu(descr->result_size));
	if (!descr->valid_size)
		dev_info(ctodev(card), "buffer full %x %x %x\n",
			 be32_to_cpu(descr->result_size),
			 be32_to_cpu(descr->buf_size),
			 be32_to_cpu(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_DESCR_DATA_STATUS_CHK_MASK) &&
		    (!(data_error & GELIC_DESCR_DATA_ERROR_CHK_MASK)))
			skb->ip_summed = CHECKSUM_UNNECESSARY;
		else
			skb->ip_summed = CHECKSUM_NONE;
	} else
		skb->ip_summed = CHECKSUM_NONE;

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

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

/**
 * gelic_net_prepare_rx_descr - reinitializes a rx descriptor
 * @card: card structure
 * @descr: descriptor to re-init
 *
 * return 0 on succes, <0 on failure
 *
 * allocates a new rx skb, iommu-maps it and attaches it to the descriptor.
 * Activate the descriptor state-wise
 */
static int gelic_net_prepare_rx_descr(struct gelic_net_card *card,
				      struct gelic_net_descr *descr)
{
	int offset;
	unsigned int bufsize;

	if (gelic_net_get_descr_status(descr) !=  GELIC_NET_DESCR_NOT_IN_USE) {
		dev_info(ctodev(card), "%s: ERROR status \n", __func__);
	}
	/* we need to round up the buffer size to a multiple of 128 */
	bufsize = ALIGN(GELIC_NET_MAX_MTU, GELIC_NET_RXBUF_ALIGN);

	/* and we need to have it 128 byte aligned, therefore we allocate a
	 * bit more */
	descr->skb = netdev_alloc_skb(card->netdev,
		bufsize + GELIC_NET_RXBUF_ALIGN - 1);
	if (!descr->skb) {
		descr->buf_addr = 0; /* tell DMAC don't touch memory */
		dev_info(ctodev(card),
			 "%s:allocate skb failed !!\n", __func__);
		return -ENOMEM;
	}
	descr->buf_size = bufsize;
	descr->dmac_cmd_status = 0;
	descr->result_size = 0;
	descr->valid_size = 0;
	descr->data_error = 0;

	offset = ((unsigned long)descr->skb->data) &
		(GELIC_NET_RXBUF_ALIGN - 1);
	if (offset)
		skb_reserve(descr->skb, GELIC_NET_RXBUF_ALIGN - offset);
	/* io-mmu-map the skb */
	descr->buf_addr = dma_map_single(ctodev(card), descr->skb->data,
					 GELIC_NET_MAX_MTU,
					 DMA_FROM_DEVICE);
	if (!descr->buf_addr) {
		dev_kfree_skb_any(descr->skb);
		descr->skb = NULL;
		dev_info(ctodev(card),
			 "%s:Could not iommu-map rx buffer\n", __func__);
		gelic_net_set_descr_status(descr, GELIC_NET_DESCR_NOT_IN_USE);
		return -ENOMEM;
	} else {
		gelic_net_set_descr_status(descr, GELIC_NET_DESCR_CARDOWNED);
		return 0;
	}
}

/**
 * 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
 */
int gelic_net_xmit(struct sk_buff *skb, struct net_device *netdev)
{
	struct gelic_card *card = netdev_card(netdev);
	struct gelic_descr *descr;
	int result;
	unsigned long flags;

	spin_lock_irqsave(&card->tx_lock, flags);

	gelic_card_release_tx_chain(card, 0);

	descr = gelic_card_get_next_tx_descr(card);
	if (!descr) {
		/*
		 * no more descriptors free
		 */
		gelic_card_stop_queues(card);
		spin_unlock_irqrestore(&card->tx_lock, flags);
		return NETDEV_TX_BUSY;
	}

	result = gelic_descr_prepare_tx(card, descr, skb);
	if (result) {
		/*
		 * DMA map failed.  As chanses are that failure
		 * would continue, just release skb and return
		 */
		netdev->stats.tx_dropped++;
		dev_kfree_skb_any(skb);
		spin_unlock_irqrestore(&card->tx_lock, flags);
		return NETDEV_TX_OK;
	}
	/*
	 * link this prepared descriptor to previous one
	 * to achieve high performance
	 */
	descr->prev->next_descr_addr = cpu_to_be32(descr->bus_addr);
	/*
	 * as hardware descriptor is modified in the above lines,
	 * ensure that the hardware sees it
	 */
	wmb();
	if (gelic_card_kick_txdma(card, descr)) {
		/*
		 * kick failed.
		 * release descriptors which were just prepared
		 */
		netdev->stats.tx_dropped++;
		gelic_descr_release_tx(card, descr);
		gelic_descr_release_tx(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_lock, flags);
	return NETDEV_TX_OK;
}

/**
 * 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;
	int count = 10;

	if (card->tx_dma_progress)
		return 0;

	if (gelic_net_get_descr_status(descr) == GELIC_NET_DESCR_CARDOWNED) {
		card->tx_dma_progress = 1;
		/* sometimes we need retry here */
		while (count--) {
			status = lv1_net_start_tx_dma(bus_id(card),
						      dev_id(card),
						      descr->bus_addr, 0);
			if (!status)
				break;
		}
		if (!count)
			dev_info(ctodev(card), "lv1_net_start_txdma failed," \
				"status=%d %#lx\n",
				 status, card->irq_status);
	}
	return status;
}

/**
 * gelic_net_open - called upon ifonfig up
 * @netdev: interface device structure
 *
 * returns 0 on success, <0 on failure
 *
 * gelic_net_open allocates all the descriptors and memory needed for
 * operation, sets up multicast list and enables interrupts
 */
static int gelic_net_open(struct net_device *netdev)
{
	struct gelic_net_card *card = netdev_priv(netdev);

	dev_dbg(ctodev(card), " -> %s:%d\n", __func__, __LINE__);

	gelic_net_open_device(card);

	if (gelic_net_init_chain(card, &card->tx_chain,
			card->descr, GELIC_NET_TX_DESCRIPTORS))
		goto alloc_tx_failed;
	if (gelic_net_init_chain(card, &card->rx_chain,
				 card->descr + GELIC_NET_TX_DESCRIPTORS,
				 GELIC_NET_RX_DESCRIPTORS))
		goto alloc_rx_failed;

	/* head of chain */
	card->tx_top = card->tx_chain.head;
	card->rx_top = card->rx_chain.head;
	dev_dbg(ctodev(card), "descr rx %p, tx %p, size %#lx, num %#x\n",
		card->rx_top, card->tx_top, sizeof(struct gelic_net_descr),
		GELIC_NET_RX_DESCRIPTORS);
	/* allocate rx skbs */
	if (gelic_net_alloc_rx_skbs(card))
		goto alloc_skbs_failed;

	card->tx_dma_progress = 0;
	card->ghiintmask = GELIC_NET_RXINT | GELIC_NET_TXINT;

	gelic_net_set_irq_mask(card, card->ghiintmask);
	gelic_net_enable_rxdmac(card);

	netif_start_queue(netdev);
	netif_carrier_on(netdev);

	return 0;

alloc_skbs_failed:
	gelic_net_free_chain(card, card->rx_top);
alloc_rx_failed:
	gelic_net_free_chain(card, card->tx_top);
alloc_tx_failed:
	return -ENOMEM;
}

/**
 * gelic_card_disable_rxdmac - disables the receive DMA controller
 * @card: card structure
 *
 * gelic_card_disable_rxdmac terminates processing on the DMA controller by
 * turing off DMA and issuing a force end
 */
static void gelic_card_disable_rxdmac(struct gelic_card *card)
{
	int status;

	/* this hvc blocks until the DMA in progress really stopped */
	status = lv1_net_stop_rx_dma(bus_id(card), dev_id(card));
	if (status)
		dev_err(ctodev(card),
			"lv1_net_stop_rx_dma failed, %d\n", status);
}

/**
 * gelic_net_disable_txdmac - disables the transmit DMA controller
 * @card: card structure
 *
 * 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_enable_rxdmac - enables the receive DMA controller
 * @card: card structure
 *
 * gelic_net_enable_rxdmac enables the DMA controller by setting RX_DMA_EN
 * in the GDADMACCNTR register
 */
static inline void gelic_net_enable_rxdmac(struct gelic_net_card *card)
{
	int status;

	status = lv1_net_start_rx_dma(bus_id(card), dev_id(card),
				card->rx_chain.tail->bus_addr, 0);
	if (status)
		dev_info(ctodev(card),
			 "lv1_net_start_rx_dma failed, status=%d\n", status);
}

/* set irq_mask */
int gelic_card_set_irq_mask(struct gelic_card *card, u64 mask)
{
	int status;

	status = lv1_net_set_interrupt_mask(bus_id(card), dev_id(card),
					    mask, 0);
	if (status)
		dev_info(ctodev(card),
			 "%s failed %d\n", __func__, status);
	return status;
}

/**
 * gelic_card_free_chain - free descriptor chain
 * @card: card structure
 * @descr_in: address of desc
 */
static void gelic_card_free_chain(struct gelic_card *card,
				  struct gelic_descr *descr_in)
{
	struct gelic_descr *descr;

	for (descr = descr_in; descr && descr->bus_addr; descr = descr->next) {
		dma_unmap_single(ctodev(card), descr->bus_addr,
				 GELIC_DESCR_SIZE, DMA_BIDIRECTIONAL);
		descr->bus_addr = 0;
	}
}

/**
 * gelic_ether_setup_netdev - initialization of net_device
 * @netdev: net_device structure
 * @card: card structure
 *
 * Returns 0 on success or <0 on failure
 *
 * gelic_ether_setup_netdev initializes the net_device structure
 * and register it.
 **/
int __devinit gelic_net_setup_netdev(struct net_device *netdev,
				     struct gelic_card *card)
{
	int status;
	u64 v1, v2;

	netdev->features = NETIF_F_IP_CSUM;

	status = lv1_net_control(bus_id(card), dev_id(card),
				 GELIC_LV1_GET_MAC_ADDRESS,
				 0, 0, 0, &v1, &v2);
	v1 <<= 16;
	if (status || !is_valid_ether_addr((u8 *)&v1)) {
		dev_info(ctodev(card),
			 "%s:lv1_net_control GET_MAC_ADDR failed %d\n",
			 __func__, status);
		return -EINVAL;
	}
	memcpy(netdev->dev_addr, &v1, ETH_ALEN);

	if (card->vlan_required) {
		netdev->hard_header_len += VLAN_HLEN;
		/*
		 * As vlan is internally used,
		 * we can not receive vlan packets
		 */
		netdev->features |= NETIF_F_VLAN_CHALLENGED;
	}

	status = register_netdev(netdev);
	if (status) {
		dev_err(ctodev(card), "%s:Couldn't register %s %d\n",
			__func__, netdev->name, status);
		return status;
	}
	dev_info(ctodev(card), "%s: MAC addr %pM\n",
		 netdev->name, netdev->dev_addr);

	return 0;
}

/**
 * gelic_descr_prepare_tx - setup a descriptor for sending packets
 * @card: card structure
 * @descr: descriptor structure
 * @skb: packet to use
 *
 * returns 0 on success, <0 on failure.
 *
 */
static int gelic_descr_prepare_tx(struct gelic_card *card,
				  struct gelic_descr *descr,
				  struct sk_buff *skb)
{
	dma_addr_t buf;

	if (card->vlan_required) {
		struct sk_buff *skb_tmp;
		enum gelic_port_type type;

		type = netdev_port(skb->dev)->type;
		skb_tmp = gelic_put_vlan_tag(skb,
					     card->vlan[type].tx);
		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 = cpu_to_be32(buf);
	descr->buf_size = cpu_to_be32(skb->len);
	descr->skb = skb;
	descr->data_status = 0;
	descr->next_descr_addr = 0; /* terminate hw descr */
	gelic_descr_set_tx_cmdstat(descr, skb);

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

/**
 * gelic_card_release_tx_chain - processes sent tx descriptors
 * @card: adapter structure
 * @stop: net_stop sequence
 *
 * releases the tx descriptors that gelic has finished with
 */
static void gelic_card_release_tx_chain(struct gelic_card *card, int stop)
{
	struct gelic_descr_chain *tx_chain;
	enum gelic_descr_dma_status status;
	struct net_device *netdev;
	int release = 0;

	for (tx_chain = &card->tx_chain;
	     tx_chain->head != tx_chain->tail && tx_chain->tail;
	     tx_chain->tail = tx_chain->tail->next) {
		status = gelic_descr_get_status(tx_chain->tail);
		netdev = tx_chain->tail->skb->dev;
		switch (status) {
		case GELIC_DESCR_DMA_RESPONSE_ERROR:
		case GELIC_DESCR_DMA_PROTECTION_ERROR:
		case GELIC_DESCR_DMA_FORCE_END:
			if (printk_ratelimit())
				dev_info(ctodev(card),
					 "%s: forcing end of tx descriptor " \
					 "with status %x\n",
					 __func__, status);
			netdev->stats.tx_dropped++;
			break;

		case GELIC_DESCR_DMA_COMPLETE:
			if (tx_chain->tail->skb) {
				netdev->stats.tx_packets++;
				netdev->stats.tx_bytes +=
					tx_chain->tail->skb->len;
			}
			break;

		case GELIC_DESCR_DMA_CARDOWNED:
			/* pending tx request */
		default:
			/* any other value (== GELIC_DESCR_DMA_NOT_IN_USE) */
			if (!stop)
				goto out;
		}
		gelic_descr_release_tx(card, tx_chain->tail);
		release ++;
	}
out:
	if (!stop && release)
		gelic_card_wake_queues(card);
}

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

	if (card->tx_dma_progress)
		return 0;

	if (gelic_descr_get_status(descr) == GELIC_DESCR_DMA_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_card_release_rx_chain - free all skb of rx descr
 * @card: card structure
 *
 */
static void gelic_card_release_rx_chain(struct gelic_card *card)
{
	struct gelic_descr *descr = card->rx_chain.head;

	do {
		if (descr->skb) {
			dma_unmap_single(ctodev(card),
					 be32_to_cpu(descr->buf_addr),
					 descr->skb->len,
					 DMA_FROM_DEVICE);
			descr->buf_addr = 0;
			dev_kfree_skb_any(descr->skb);
			descr->skb = NULL;
			gelic_descr_set_status(descr,
					       GELIC_DESCR_DMA_NOT_IN_USE);
		}
		descr = descr->next;
	} while (descr != card->rx_chain.head);
}