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authorSamuel Ortiz <sameo@linux.intel.com>2011-08-19 15:47:11 +0200
committerJohn W. Linville <linville@tuxdriver.com>2011-08-24 14:41:44 -0400
commite8753043f9fbabffbf087c7f4b514c50ef89541e (patch)
tree2c4b382a21500c228005a43e48134d39fdcccbe8 /net/nfc
parent4e0d8cc1006b889909a87f824943bad9a56358e8 (diff)
downloadblackbird-op-linux-e8753043f9fbabffbf087c7f4b514c50ef89541e.tar.gz
blackbird-op-linux-e8753043f9fbabffbf087c7f4b514c50ef89541e.zip
NFC: Reserve tx head and tail room
We can have the NFC core layer allocating the tx head and tail room for the drivers and avoid 1 or more SKBs copy on write on the Tx path. Signed-off-by: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/nfc')
-rw-r--r--net/nfc/core.c6
-rw-r--r--net/nfc/rawsock.c13
2 files changed, 11 insertions, 8 deletions
diff --git a/net/nfc/core.c b/net/nfc/core.c
index b6fd4e1f2057..284e2f6a14ff 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -322,7 +322,9 @@ struct nfc_dev *nfc_get_device(unsigned idx)
* @supported_protocols: NFC protocols supported by the device
*/
struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
- u32 supported_protocols)
+ u32 supported_protocols,
+ int tx_headroom,
+ int tx_tailroom)
{
static atomic_t dev_no = ATOMIC_INIT(0);
struct nfc_dev *dev;
@@ -345,6 +347,8 @@ struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
dev->ops = ops;
dev->supported_protocols = supported_protocols;
+ dev->tx_headroom = tx_headroom;
+ dev->tx_tailroom = tx_tailroom;
spin_lock_init(&dev->targets_lock);
nfc_genl_data_init(&dev->genl_data);
diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c
index 52de84a55115..9fd652a51424 100644
--- a/net/nfc/rawsock.c
+++ b/net/nfc/rawsock.c
@@ -123,11 +123,7 @@ error:
static int rawsock_add_header(struct sk_buff *skb)
{
-
- if (skb_cow_head(skb, 1))
- return -ENOMEM;
-
- *skb_push(skb, 1) = 0;
+ *skb_push(skb, NFC_HEADER_SIZE) = 0;
return 0;
}
@@ -197,6 +193,7 @@ static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
+ struct nfc_dev *dev = nfc_rawsock(sk)->dev;
struct sk_buff *skb;
int rc;
@@ -208,11 +205,13 @@ static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
if (sock->state != SS_CONNECTED)
return -ENOTCONN;
- skb = sock_alloc_send_skb(sk, len, msg->msg_flags & MSG_DONTWAIT,
- &rc);
+ skb = sock_alloc_send_skb(sk, len + dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE,
+ msg->msg_flags & MSG_DONTWAIT, &rc);
if (!skb)
return rc;
+ skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
+
rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
if (rc < 0) {
kfree_skb(skb);
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