Re: [PATCH V3 2/8] Add a new zerocopy device flag

From: Ben Hutchings
Date: Wed Apr 20 2011 - 15:48:34 EST


On Wed, 2011-04-20 at 12:44 -0700, Shirley Ma wrote:
> This zerocopy flag is used to support device DMA userspace buffers.
>
> Signed-off-by: Shirley Ma <xma@xxxxxxxxxx>
> ---
>
> include/linux/netdevice.h | 3 +++
> 1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 0249fe7..0998d3d 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1067,6 +1067,9 @@ struct net_device {
> #define NETIF_F_RXHASH (1 << 28) /* Receive hashing offload */
> #define NETIF_F_RXCSUM (1 << 29) /* Receive checksumming offload */
>
> +/* bit 29 is for device to map userspace buffers -- zerocopy */
> +#define NETIF_F_ZEROCOPY (1 << 29)

Look above.

Ben.

> /* Segmentation offload features */
> #define NETIF_F_GSO_SHIFT 16
> #define NETIF_F_GSO_MASK 0x00ff0000
>
>
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--
Ben Hutchings, Senior Software Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

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