2018-05-18 19:00:21 +07:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
|
/* XDP user-space packet buffer
|
2018-05-02 18:01:23 +07:00
|
|
|
* Copyright(c) 2018 Intel Corporation.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#ifndef XDP_UMEM_H_
|
|
|
|
|
#define XDP_UMEM_H_
|
|
|
|
|
|
2018-06-04 19:05:51 +07:00
|
|
|
#include <net/xdp_sock.h>
|
2018-05-02 18:01:23 +07:00
|
|
|
|
xsk: new descriptor addressing scheme
Currently, AF_XDP only supports a fixed frame-size memory scheme where
each frame is referenced via an index (idx). A user passes the frame
index to the kernel, and the kernel acts upon the data. Some NICs,
however, do not have a fixed frame-size model, instead they have a
model where a memory window is passed to the hardware and multiple
frames are filled into that window (referred to as the "type-writer"
model).
By changing the descriptor format from the current frame index
addressing scheme, AF_XDP can in the future be extended to support
these kinds of NICs.
In the index-based model, an idx refers to a frame of size
frame_size. Addressing a frame in the UMEM is done by offseting the
UMEM starting address by a global offset, idx * frame_size + offset.
Communicating via the fill- and completion-rings are done by means of
idx.
In this commit, the idx is removed in favor of an address (addr),
which is a relative address ranging over the UMEM. To convert an
idx-based address to the new addr is simply: addr = idx * frame_size +
offset.
We also stop referring to the UMEM "frame" as a frame. Instead it is
simply called a chunk.
To transfer ownership of a chunk to the kernel, the addr of the chunk
is passed in the fill-ring. Note, that the kernel will mask addr to
make it chunk aligned, so there is no need for userspace to do
that. E.g., for a chunk size of 2k, passing an addr of 2048, 2050 or
3000 to the fill-ring will refer to the same chunk.
On the completion-ring, the addr will match that of the Tx descriptor,
passed to the kernel.
Changing the descriptor format to use chunks/addr will allow for
future changes to move to a type-writer based model, where multiple
frames can reside in one chunk. In this model passing one single chunk
into the fill-ring, would potentially result in multiple Rx
descriptors.
This commit changes the uapi of AF_XDP sockets, and updates the
documentation.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-06-04 18:57:13 +07:00
|
|
|
static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
|
2018-05-02 18:01:27 +07:00
|
|
|
{
|
2018-06-04 19:05:52 +07:00
|
|
|
return umem->pages[addr >> PAGE_SHIFT].addr + (addr & (PAGE_SIZE - 1));
|
2018-05-02 18:01:27 +07:00
|
|
|
}
|
|
|
|
|
|
2018-06-04 19:05:57 +07:00
|
|
|
static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
|
|
|
|
|
{
|
|
|
|
|
return umem->pages[addr >> PAGE_SHIFT].dma + (addr & (PAGE_SIZE - 1));
|
|
|
|
|
}
|
|
|
|
|
|
2018-06-04 19:05:55 +07:00
|
|
|
int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
|
|
|
|
|
u32 queue_id, u16 flags);
|
2018-05-02 18:01:26 +07:00
|
|
|
bool xdp_umem_validate_queues(struct xdp_umem *umem);
|
2018-05-02 18:01:23 +07:00
|
|
|
void xdp_get_umem(struct xdp_umem *umem);
|
|
|
|
|
void xdp_put_umem(struct xdp_umem *umem);
|
2018-06-04 19:05:57 +07:00
|
|
|
void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs);
|
|
|
|
|
void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs);
|
2018-05-22 14:35:02 +07:00
|
|
|
struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr);
|
2018-05-02 18:01:23 +07:00
|
|
|
|
|
|
|
|
#endif /* XDP_UMEM_H_ */
|