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Message-ID: <547E2191.2090909@oracle.com>
Date: Tue, 02 Dec 2014 15:31:13 -0500
From: David L Stevens <david.stevens@...cle.com>
To: David Miller <davem@...emloft.net>
CC: netdev@...r.kernel.org,
Sowmini Varadhan <sowmini.varadhan@...cle.com>
Subject: [PATCH net-next 3/6] sunvnet: add scatter/gather support
This patch adds scatter/gather support to the sunvnet driver.
Signed-off-by: David L Stevens <david.stevens@...cle.com>
---
drivers/net/ethernet/sun/sunvnet.c | 97 ++++++++++++++++++++++++++++--------
1 files changed, 76 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c
index 7a8da56..b6a5336 100644
--- a/drivers/net/ethernet/sun/sunvnet.c
+++ b/drivers/net/ethernet/sun/sunvnet.c
@@ -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,
- (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");
--
1.7.1
--
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