xdp: introduce a new xdp_frame type

This is needed to convert drivers tuntap and virtio_net.

This is a generalization of what is done inside cpumap, which will be
converted later.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesper Dangaard Brouer 2018-04-17 16:45:42 +02:00 committed by David S. Miller
parent 106ca27f29
commit c0048cff8a

View file

@ -58,6 +58,46 @@ struct xdp_buff {
struct xdp_rxq_info *rxq;
};
struct xdp_frame {
void *data;
u16 len;
u16 headroom;
u16 metasize;
/* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time,
* while mem info is valid on remote CPU.
*/
struct xdp_mem_info mem;
};
/* Convert xdp_buff to xdp_frame */
static inline
struct xdp_frame *convert_to_xdp_frame(struct xdp_buff *xdp)
{
struct xdp_frame *xdp_frame;
int metasize;
int headroom;
/* Assure headroom is available for storing info */
headroom = xdp->data - xdp->data_hard_start;
metasize = xdp->data - xdp->data_meta;
metasize = metasize > 0 ? metasize : 0;
if (unlikely((headroom - metasize) < sizeof(*xdp_frame)))
return NULL;
/* Store info in top of packet */
xdp_frame = xdp->data_hard_start;
xdp_frame->data = xdp->data;
xdp_frame->len = xdp->data_end - xdp->data;
xdp_frame->headroom = headroom - sizeof(*xdp_frame);
xdp_frame->metasize = metasize;
/* rxq only valid until napi_schedule ends, convert to xdp_mem_info */
xdp_frame->mem = xdp->rxq->mem;
return xdp_frame;
}
static inline
void xdp_return_frame(void *data, struct xdp_mem_info *mem)
{