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Commit da38c564 authored by David L Stevens's avatar David L Stevens Committed by David S. Miller
Browse files

sunvnet: add scatter/gather support 



This patch adds scatter/gather support to the sunvnet driver.

Signed-off-by: default avatarDavid L Stevens <david.stevens@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6d0ba919

drivers/net/ethernet/sun/sunvnet.c

+76 −21
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/ethtool.h>

#include <linux/etherdevice.h>

#include <linux/mutex.h>

#include <linux/highmem.h>

#include <linux/if_vlan.h>



#if IS_ENABLED(CONFIG_IPV6)
@@ -978,11 +979,54 @@ static void vnet_clean_timer_expire(unsigned long port0) 
		del_timer(&port->clean_timer);

}



static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, void **pstart,

					     int *plen)

static inline int vnet_skb_map(struct ldc_channel *lp, struct sk_buff *skb,

			       struct ldc_trans_cookie *cookies, int ncookies,

			       unsigned int map_perm)

{

	int i, nc, err, blen;



	/* header */

	blen = skb_headlen(skb);

	if (blen < ETH_ZLEN)

		blen = ETH_ZLEN;

	blen += VNET_PACKET_SKIP;

	blen += 8 - (blen & 7);



	err = ldc_map_single(lp, skb->data-VNET_PACKET_SKIP, blen, cookies,

			     ncookies, map_perm);

	if (err < 0)

		return err;

	nc = err;



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

		skb_frag_t *f = &skb_shinfo(skb)->frags[i];

		u8 *vaddr;



		if (nc < ncookies) {

			vaddr = kmap_atomic(skb_frag_page(f));

			blen = skb_frag_size(f);

			blen += 8 - (blen & 7);

			err = ldc_map_single(lp, vaddr + f->page_offset,

					     blen, cookies + nc, ncookies - nc,

					     map_perm);

			kunmap_atomic(vaddr);

		} else {

			err = -EMSGSIZE;

		}



		if (err < 0) {

			ldc_unmap(lp, cookies, nc);

			return err;

		}

		nc += err;

	}

	return nc;

}



static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, int ncookies)

{

	struct sk_buff *nskb;

	int len, pad;

	int i, len, pad, docopy;



	len = skb->len;

	pad = 0;
@@ -992,14 +1036,25 @@ static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, void **pstart, 
	}

	len += VNET_PACKET_SKIP;

	pad += 8 - (len & 7);

	len += 8 - (len & 7);



	/* make sure we have enough cookies and alignment in every frag */

	docopy = skb_shinfo(skb)->nr_frags >= ncookies;

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

		skb_frag_t *f = &skb_shinfo(skb)->frags[i];



		docopy |= f->page_offset & 7;

	}

	if (((unsigned long)skb->data & 7) != VNET_PACKET_SKIP ||

	    skb_tailroom(skb) < pad ||

	    skb_headroom(skb) < VNET_PACKET_SKIP) {

	    skb_headroom(skb) < VNET_PACKET_SKIP || docopy) {

		int offset;



		nskb = alloc_and_align_skb(skb->dev, skb->len);

		len = skb->len > ETH_ZLEN ? skb->len : ETH_ZLEN;

		nskb = alloc_and_align_skb(skb->dev, len);

		if (nskb == NULL) {

			dev_kfree_skb(skb);

			return NULL;

		}

		skb_reserve(nskb, VNET_PACKET_SKIP);



		nskb->protocol = skb->protocol;
@@ -1022,9 +1077,6 @@ static inline struct sk_buff *vnet_skb_shape(struct sk_buff *skb, void **pstart, 
		dev_kfree_skb(skb);

		skb = nskb;

	}



	*pstart = skb->data - VNET_PACKET_SKIP;

	*plen = len;

	return skb;

}
@@ -1049,15 +1101,9 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	unsigned int len;

	struct sk_buff *freeskbs = NULL;

	int i, err, txi;

	void *start = NULL;

	int nlen = 0;

	unsigned pending = 0;

	struct netdev_queue *txq;



	skb = vnet_skb_shape(skb, &start, &nlen);

	if (unlikely(!skb))

		goto out_dropped;



	rcu_read_lock();

	port = __tx_port_find(vp, skb);

	if (unlikely(!port)) {
@@ -1097,6 +1143,13 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev) 
		goto out_dropped;

	}



	skb = vnet_skb_shape(skb, 2);



	if (unlikely(!skb)) {

		rcu_read_unlock();

		goto out_dropped;

	}



	dr = &port->vio.drings[VIO_DRIVER_TX_RING];

	i = skb_get_queue_mapping(skb);

	txq = netdev_get_tx_queue(dev, i);
@@ -1124,16 +1177,15 @@ static int vnet_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	if (len < ETH_ZLEN)

		len = ETH_ZLEN;



	port->tx_bufs[txi].skb = skb;

	skb = NULL;



	err = ldc_map_single(port->vio.lp, start, nlen,

			     port->tx_bufs[txi].cookies, VNET_MAXCOOKIES,

	err = vnet_skb_map(port->vio.lp, skb, port->tx_bufs[txi].cookies, 2,

			   (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW));

	if (err < 0) {

		netdev_info(dev, "tx buffer map error %d\n", err);

		goto out_dropped;

	}



	port->tx_bufs[txi].skb = skb;

	skb = NULL;

	port->tx_bufs[txi].ncookies = err;



	/* We don't rely on the ACKs to free the skb in vnet_start_xmit(),
@@ -1559,6 +1611,9 @@ static struct vnet *vnet_new(const u64 *local_mac) 
	dev->ethtool_ops = &vnet_ethtool_ops;

	dev->watchdog_timeo = VNET_TX_TIMEOUT;



	dev->hw_features = NETIF_F_SG;

	dev->features = dev->hw_features;



	err = register_netdev(dev);

	if (err) {

		pr_err("Cannot register net device, aborting\n");