Hi Samuel,
That's ok, nice work.
Regards,
Aloisio
On Fri, Aug 19, 2011 at 10:47 AM, Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxxxxxxx>
> ---
> drivers/nfc/pn533.c | 17 +++--------------
> include/linux/nfc.h | 2 ++
> include/net/nfc.h | 7 ++++++-
> net/nfc/core.c | 6 +++++-
> net/nfc/rawsock.c | 13 ++++++-------
> 5 files changed, 22 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
> index c77e054..f81a93e 100644
> --- a/drivers/nfc/pn533.c
> +++ b/drivers/nfc/pn533.c
> @@ -1246,7 +1246,6 @@ static int pn533_data_exchange_tx_frame(struct pn533 *dev, struct sk_buff *skb)
> {
> int payload_len = skb->len;
> struct pn533_frame *out_frame;
> - struct sk_buff *discarded;
> u8 tg;
>
> nfc_dev_dbg(&dev->interface->dev, "%s - Sending %d bytes", __func__,
> @@ -1260,18 +1259,6 @@ static int pn533_data_exchange_tx_frame(struct pn533 *dev, struct sk_buff *skb)
> return -ENOSYS;
> }
>
> - /* Reserving header space */
> - if (skb_cow_head(skb, PN533_CMD_DATAEXCH_HEAD_LEN)) {
> - nfc_dev_err(&dev->interface->dev, "Error to add header data");
> - return -ENOMEM;
> - }
> -
> - /* Reserving tail space, see pn533_tx_frame_finish */
> - if (skb_cow_data(skb, PN533_FRAME_TAIL_SIZE, &discarded) < 0) {
> - nfc_dev_err(&dev->interface->dev, "Error to add tail data");
> - return -ENOMEM;
> - }
> -
> skb_push(skb, PN533_CMD_DATAEXCH_HEAD_LEN);
> out_frame = (struct pn533_frame *) skb->data;
>
> @@ -1536,7 +1523,9 @@ static int pn533_probe(struct usb_interface *interface,
> | NFC_PROTO_ISO14443_MASK
> | NFC_PROTO_NFC_DEP_MASK;
>
> - dev->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols);
> + dev->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols,
> + PN533_CMD_DATAEXCH_HEAD_LEN,
> + PN533_FRAME_TAIL_SIZE);
> if (!dev->nfc_dev)
> goto kill_tasklet;
>
> diff --git a/include/linux/nfc.h b/include/linux/nfc.h
> index 330a4c5..c525e0b 100644
> --- a/include/linux/nfc.h
> +++ b/include/linux/nfc.h
> @@ -123,4 +123,6 @@ struct sockaddr_nfc {
> #define NFC_SOCKPROTO_RAW 0
> #define NFC_SOCKPROTO_MAX 1
>
> +#define NFC_HEADER_SIZE 1
> +
> #endif /*__LINUX_NFC_H */
> diff --git a/include/net/nfc.h b/include/net/nfc.h
> index cc01303..87b51fe 100644
> --- a/include/net/nfc.h
> +++ b/include/net/nfc.h
> @@ -82,6 +82,9 @@ struct nfc_dev {
> struct nfc_genl_data genl_data;
> u32 supported_protocols;
>
> + int tx_headroom;
> + int tx_tailroom;
> +
> struct nfc_ops *ops;
> };
> #define to_nfc_dev(_dev) container_of(_dev, struct nfc_dev, dev)
> @@ -89,7 +92,9 @@ struct nfc_dev {
> extern struct class nfc_class;
>
> struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
> - u32 supported_protocols);
> + u32 supported_protocols,
> + int tx_headroom,
> + int tx_tailroom);
>
> /**
> * nfc_free_device - free nfc device
> diff --git a/net/nfc/core.c b/net/nfc/core.c
> index b6fd4e1..284e2f6 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 52de84a..9fd652a 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);
> --
> 1.7.5.3
>
> --
> Intel Open Source Technology Centre
> http://oss.intel.com/
>
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