Messages in this thread Patch in this message | | | Subject | [PATCH V4 2/8] netdevice.h: Add a new zerocopy device flag | From | Shirley Ma <> | Date | Wed, 04 May 2011 00:55:17 -0700 |
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Signed-off-by: Shirley Ma <xma@us.ibm.com> ---
include/linux/netdevice.h | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 0249fe7..0808f1e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1067,6 +1067,16 @@ struct net_device { #define NETIF_F_RXHASH (1 << 28) /* Receive hashing offload */ #define NETIF_F_RXCSUM (1 << 29) /* Receive checksumming offload */ +/* + * Bit 31 is for device to map userspace buffers -- zerocopy + * Device can set this flag when it supports HIGHDMA. + * Device can't recycle this kind of skb buffers. + * There are 256 bytes copied, the rest of buffers are mapped. + * The userspace callback should only be called when last reference to this skb + * is gone. + */ +#define NETIF_F_ZEROCOPY (1 << 31) + /* Segmentation offload features */ #define NETIF_F_GSO_SHIFT 16 #define NETIF_F_GSO_MASK 0x00ff0000
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