From da38c56417deede2ab223a77bff098843adac7d9 Mon Sep 17 00:00:00 2001 From: David L Stevens Date: Tue, 2 Dec 2014 15:31:13 -0500 Subject: [PATCH] sunvnet: add scatter/gather support This patch adds scatter/gather support to the sunvnet driver. Signed-off-by: David L Stevens Signed-off-by: David S. Miller --- drivers/net/ethernet/sun/sunvnet.c | 97 +++++++++++++++++++++++++++++--------- 1 file changed, 76 insertions(+), 21 deletions(-) diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c index 7a8da56..b6a53367 100644 --- a/drivers/net/ethernet/sun/sunvnet.c +++ b/drivers/net/ethernet/sun/sunvnet.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #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, - (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW)); + 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"); -- 2.7.4