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Commit 924cc268 authored by David Daney's avatar David Daney Committed by Ralf Baechle
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Staging: Octeon Ethernet: Enable scatter-gather. 



Octeon ethernet hardware can handle NETIF_F_SG, so we enable it.

A gather list of up to six fragments will fit in the SKB's CB
structure, so no extra memory is required.  If a SKB has more than six
fragments, we must linearize it.

Signed-off-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
To: gregkh@suse.de
Patchwork: http://patchwork.linux-mips.org/patch/838/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 3368c784

drivers/staging/octeon/ethernet-tx.c

+50 −7
Original line number Diff line number Diff line
@@ -53,6 +53,8 @@ 


#include "cvmx-gmxx-defs.h"



#define CVM_OCT_SKB_CB(skb)	((u64 *)((skb)->cb))



/*

 * You can define GET_SKBUFF_QOS() to override how the skbuff output

 * function determines which output queue is used. The default
@@ -121,6 +123,7 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev) 
	uint64_t old_scratch;

	uint64_t old_scratch2;

	int qos;

	int i;

	enum {QUEUE_CORE, QUEUE_HW, QUEUE_DROP} queue_type;

	struct octeon_ethernet *priv = netdev_priv(dev);

	struct sk_buff *to_free_list;
@@ -170,6 +173,28 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev) 
					       MAX_SKB_TO_FREE);

	}



	/*

	 * We have space for 6 segment pointers, If there will be more

	 * than that, we must linearize.

	 */

	if (unlikely(skb_shinfo(skb)->nr_frags > 5)) {

		if (unlikely(__skb_linearize(skb))) {

			queue_type = QUEUE_DROP;

			if (USE_ASYNC_IOBDMA) {

				/* Get the number of skbuffs in use by the hardware */

				CVMX_SYNCIOBDMA;

				skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);

			} else {

				/* Get the number of skbuffs in use by the hardware */

				skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,

								       MAX_SKB_TO_FREE);

			}

			skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau + qos * 4);

			spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);

			goto skip_xmit;

		}

	}



	/*

	 * The CN3XXX series of parts has an errata (GMX-401) which

	 * causes the GMX block to hang if a collision occurs towards
@@ -198,13 +223,6 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev) 
		}

	}



	/* Build the PKO buffer pointer */

	hw_buffer.u64 = 0;

	hw_buffer.s.addr = cvmx_ptr_to_phys(skb->data);

	hw_buffer.s.pool = 0;

	hw_buffer.s.size =

	    (unsigned long)skb_end_pointer(skb) - (unsigned long)skb->head;



	/* Build the PKO command */

	pko_command.u64 = 0;

	pko_command.s.n2 = 1;	/* Don't pollute L2 with the outgoing packet */
@@ -215,6 +233,31 @@ int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev) 


	pko_command.s.dontfree = 1;

	pko_command.s.reg0 = priv->fau + qos * 4;



	/* Build the PKO buffer pointer */

	hw_buffer.u64 = 0;

	if (skb_shinfo(skb)->nr_frags == 0) {

		hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);

		hw_buffer.s.pool = 0;

		hw_buffer.s.size = skb->len;

	} else {

		hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);

		hw_buffer.s.pool = 0;

		hw_buffer.s.size = skb_headlen(skb);

		CVM_OCT_SKB_CB(skb)[0] = hw_buffer.u64;

		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {

			struct skb_frag_struct *fs = skb_shinfo(skb)->frags + i;

			hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)(page_address(fs->page) + fs->page_offset));

			hw_buffer.s.size = fs->size;

			CVM_OCT_SKB_CB(skb)[i + 1] = hw_buffer.u64;

		}

		hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)CVM_OCT_SKB_CB(skb));

		hw_buffer.s.size = skb_shinfo(skb)->nr_frags + 1;

		pko_command.s.segs = skb_shinfo(skb)->nr_frags + 1;

		pko_command.s.gather = 1;

		goto dont_put_skbuff_in_hw;

	}



	/*

	 * See if we can put this skb in the FPA pool. Any strange

	 * behavior from the Linux networking stack will most likely

drivers/staging/octeon/ethernet.c

+5 −2
Original line number Diff line number Diff line
@@ -484,8 +484,11 @@ int cvm_oct_common_init(struct net_device *dev) 
	    && (always_use_pow || strstr(pow_send_list, dev->name)))

		priv->queue = -1;



	if (priv->queue != -1 && USE_HW_TCPUDP_CHECKSUM)

	if (priv->queue != -1) {

		dev->features |= NETIF_F_SG;

		if (USE_HW_TCPUDP_CHECKSUM)

			dev->features |= NETIF_F_IP_CSUM;

	}



	/* We do our own locking, Linux doesn't need to */

	dev->features |= NETIF_F_LLTX;