pasemi_mac: implement sg support (ad3c20d1) · Commits · github.com / kvm-riscv / linux

drivers/net/pasemi_mac.c

+117 −46

Original line number	Diff line number	Diff line
		@@ -160,6 +160,30 @@ static int pasemi_get_mac_addr(struct pasemi_mac *mac)
		return 0;
		}

		static int pasemi_mac_unmap_tx_skb(struct pasemi_mac *mac,
		struct sk_buff *skb,
		dma_addr_t *dmas)
		{
		int f;
		int nfrags = skb_shinfo(skb)->nr_frags;

		pci_unmap_single(mac->dma_pdev, dmas[0], skb_headlen(skb),
		PCI_DMA_TODEVICE);

		for (f = 0; f < nfrags; f++) {
		skb_frag_t *frag = &skb_shinfo(skb)->frags[f];

		pci_unmap_page(mac->dma_pdev, dmas[f+1], frag->size,
		PCI_DMA_TODEVICE);
		}
		dev_kfree_skb_irq(skb);

		/* Freed descriptor slot + main SKB ptr + nfrags additional ptrs,
		* aligned up to a power of 2
		*/
		return (nfrags + 3) & ~1;
		}

		static int pasemi_mac_setup_rx_resources(struct net_device *dev)
		{
		struct pasemi_mac_rxring *ring;
		@@ -300,23 +324,23 @@ static int pasemi_mac_setup_tx_resources(struct net_device *dev)
		static void pasemi_mac_free_tx_resources(struct net_device *dev)
		{
		struct pasemi_mac *mac = netdev_priv(dev);
		unsigned int i;
		unsigned int i, j;
		struct pasemi_mac_buffer *info;
		dma_addr_t dmas[MAX_SKB_FRAGS+1];
		int freed;

		for (i = 0; i < TX_RING_SIZE; i += 2) {
		for (i = 0; i < TX_RING_SIZE; i += freed) {
		info = &TX_RING_INFO(mac, i+1);
		if (info->dma && info->skb) {
		pci_unmap_single(mac->dma_pdev,
		info->dma,
		info->skb->len,
		PCI_DMA_TODEVICE);
		dev_kfree_skb_any(info->skb);
		for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++)
		dmas[j] = TX_RING_INFO(mac, i+1+j).dma;
		freed = pasemi_mac_unmap_tx_skb(mac, info->skb, dmas);
		} else
		freed = 2;
		}

		for (i = 0; i < TX_RING_SIZE; i++)
		TX_RING(mac, i) = 0;
		TX_RING(mac, i+1) = 0;
		info->dma = 0;
		info->skb = NULL;
		}

		dma_free_coherent(&mac->dma_pdev->dev,
		TX_RING_SIZE * sizeof(u64),
		@@ -573,27 +597,34 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
		return count;
		}

		/* Can't make this too large or we blow the kernel stack limits */
		#define TX_CLEAN_BATCHSIZE (128/MAX_SKB_FRAGS)

		static int pasemi_mac_clean_tx(struct pasemi_mac *mac)
		{
		int i;
		int i, j;
		struct pasemi_mac_buffer *info;
		unsigned int start, count, limit;
		unsigned int start, descr_count, buf_count, limit;
		unsigned int total_count;
		unsigned long flags;
		struct sk_buff *skbs[32];
		dma_addr_t dmas[32];
		struct sk_buff *skbs[TX_CLEAN_BATCHSIZE];
		dma_addr_t dmas[TX_CLEAN_BATCHSIZE][MAX_SKB_FRAGS+1];

		total_count = 0;
		limit = TX_CLEAN_BATCHSIZE;
		restart:
		spin_lock_irqsave(&mac->tx->lock, flags);

		start = mac->tx->next_to_clean;
		limit = min(mac->tx->next_to_fill, start+32);

		count = 0;
		buf_count = 0;
		descr_count = 0;

		for (i = start; i < limit; i += 2) {
		for (i = start;
		descr_count < limit && i < mac->tx->next_to_fill;
		i += buf_count) {
		u64 mactx = TX_RING(mac, i);

		if ((mactx & XCT_MACTX_E) \|\|
		(*mac->tx_status & PAS_STATUS_ERROR))
		pasemi_mac_tx_error(mac, mactx);
		@@ -603,30 +634,38 @@ static int pasemi_mac_clean_tx(struct pasemi_mac *mac)
		break;

		info = &TX_RING_INFO(mac, i+1);
		skbs[count] = info->skb;
		dmas[count] = info->dma;
		skbs[descr_count] = info->skb;

		buf_count = 2 + skb_shinfo(info->skb)->nr_frags;
		for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++)
		dmas[descr_count][j] = TX_RING_INFO(mac, i+1+j).dma;


		info->dma = 0;
		TX_RING(mac, i) = 0;
		TX_RING(mac, i+1) = 0;
		TX_RING_INFO(mac, i+1).skb = 0;
		TX_RING_INFO(mac, i+1).dma = 0;


		count++;
		/* Since we always fill with an even number of entries, make
		* sure we skip any unused one at the end as well.
		*/
		if (buf_count & 1)
		buf_count++;
		descr_count++;
		}
		mac->tx->next_to_clean += count * 2;
		mac->tx->next_to_clean = i;

		spin_unlock_irqrestore(&mac->tx->lock, flags);
		netif_wake_queue(mac->netdev);

		for (i = 0; i < count; i++) {
		pci_unmap_single(mac->dma_pdev, dmas[i],
		skbs[i]->len, PCI_DMA_TODEVICE);
		dev_kfree_skb_irq(skbs[i]);
		}
		for (i = 0; i < descr_count; i++)
		pasemi_mac_unmap_tx_skb(mac, skbs[i], dmas[i]);

		total_count += count;
		total_count += descr_count;

		/* If the batch was full, try to clean more */
		if (count == 32)
		if (descr_count == limit)
		goto restart;

		return total_count;
		@@ -997,9 +1036,11 @@ static int pasemi_mac_start_tx(struct sk_buff skb, struct net_device dev)
		{
		struct pasemi_mac *mac = netdev_priv(dev);
		struct pasemi_mac_txring *txring;
		u64 dflags, mactx, ptr;
		dma_addr_t map;
		u64 dflags, mactx;
		dma_addr_t map[MAX_SKB_FRAGS+1];
		unsigned int map_size[MAX_SKB_FRAGS+1];
		unsigned long flags;
		int i, nfrags;

		dflags = XCT_MACTX_O \| XCT_MACTX_ST \| XCT_MACTX_SS \| XCT_MACTX_CRC_PAD;

		@@ -1020,25 +1061,40 @@ static int pasemi_mac_start_tx(struct sk_buff skb, struct net_device dev)
		}
		}

		map = pci_map_single(mac->dma_pdev, skb->data, skb->len, PCI_DMA_TODEVICE);
		nfrags = skb_shinfo(skb)->nr_frags;

		if (dma_mapping_error(map))
		return NETDEV_TX_BUSY;
		map[0] = pci_map_single(mac->dma_pdev, skb->data, skb_headlen(skb),
		PCI_DMA_TODEVICE);
		map_size[0] = skb_headlen(skb);
		if (dma_mapping_error(map[0]))
		goto out_err_nolock;

		for (i = 0; i < nfrags; i++) {
		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

		map[i+1] = pci_map_page(mac->dma_pdev, frag->page,
		frag->page_offset, frag->size,
		PCI_DMA_TODEVICE);
		map_size[i+1] = frag->size;
		if (dma_mapping_error(map[i+1])) {
		nfrags = i;
		goto out_err_nolock;
		}
		}

		mactx = dflags \| XCT_MACTX_LLEN(skb->len);
		ptr = XCT_PTR_LEN(skb->len) \| XCT_PTR_ADDR(map);

		txring = mac->tx;

		spin_lock_irqsave(&txring->lock, flags);

		if (RING_AVAIL(txring) <= 2) {
		if (RING_AVAIL(txring) <= nfrags+3) {
		spin_unlock_irqrestore(&txring->lock, flags);
		pasemi_mac_clean_tx(mac);
		pasemi_mac_restart_tx_intr(mac);
		spin_lock_irqsave(&txring->lock, flags);

		if (RING_AVAIL(txring) <= 2) {
		if (RING_AVAIL(txring) <= nfrags+3) {
		/* Still no room -- stop the queue and wait for tx
		* intr when there's room.
		*/
		@@ -1048,25 +1104,40 @@ static int pasemi_mac_start_tx(struct sk_buff skb, struct net_device dev)
		}

		TX_RING(mac, txring->next_to_fill) = mactx;
		TX_RING(mac, txring->next_to_fill+1) = ptr;
		txring->next_to_fill++;
		TX_RING_INFO(mac, txring->next_to_fill).skb = skb;
		for (i = 0; i <= nfrags; i++) {
		TX_RING(mac, txring->next_to_fill+i) =
		XCT_PTR_LEN(map_size[i]) \| XCT_PTR_ADDR(map[i]);
		TX_RING_INFO(mac, txring->next_to_fill+i).dma = map[i];
		}

		/* We have to add an even number of 8-byte entries to the ring
		* even if the last one is unused. That means always an odd number
		* of pointers + one mactx descriptor.
		*/
		if (nfrags & 1)
		nfrags++;

		TX_RING_INFO(mac, txring->next_to_fill+1).dma = map;
		TX_RING_INFO(mac, txring->next_to_fill+1).skb = skb;
		txring->next_to_fill += nfrags + 1;

		txring->next_to_fill += 2;

		dev->stats.tx_packets++;
		dev->stats.tx_bytes += skb->len;

		spin_unlock_irqrestore(&txring->lock, flags);

		write_dma_reg(mac, PAS_DMA_TXCHAN_INCR(mac->dma_txch), 1);
		write_dma_reg(mac, PAS_DMA_TXCHAN_INCR(mac->dma_txch), (nfrags+2) >> 1);

		return NETDEV_TX_OK;

		out_err:
		spin_unlock_irqrestore(&txring->lock, flags);
		pci_unmap_single(mac->dma_pdev, map, skb->len, PCI_DMA_TODEVICE);
		out_err_nolock:
		while (nfrags--)
		pci_unmap_single(mac->dma_pdev, map[nfrags], map_size[nfrags],
		PCI_DMA_TODEVICE);

		return NETDEV_TX_BUSY;
		}

		@@ -1202,7 +1273,7 @@ pasemi_mac_probe(struct pci_dev pdev, const struct pci_device_id ent)

		netif_napi_add(dev, &mac->napi, pasemi_mac_poll, 64);

		dev->features = NETIF_F_HW_CSUM \| NETIF_F_LLTX;
		dev->features = NETIF_F_HW_CSUM \| NETIF_F_LLTX \| NETIF_F_SG;

		/* These should come out of the device tree eventually */
		mac->dma_txch = index;