linux-yocto/include/net/xdp_sock_drv.h
Björn Töpel 2b43470add xsk: Introduce AF_XDP buffer allocation API
In order to simplify AF_XDP zero-copy enablement for NIC driver
developers, a new AF_XDP buffer allocation API is added. The
implementation is based on a single core (single producer/consumer)
buffer pool for the AF_XDP UMEM.

A buffer is allocated using the xsk_buff_alloc() function, and
returned using xsk_buff_free(). If a buffer is disassociated with the
pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is
said to be released. Currently, the release function is only used by
the AF_XDP internals and not visible to the driver.

Drivers using this API should register the XDP memory model with the
new MEM_TYPE_XSK_BUFF_POOL type.

The API is defined in net/xdp_sock_drv.h.

The buffer type is struct xdp_buff, and follows the lifetime of
regular xdp_buffs, i.e.  the lifetime of an xdp_buff is restricted to
a NAPI context. In other words, the API is not replacing xdp_frames.

In addition to introducing the API and implementations, the AF_XDP
core is migrated to use the new APIs.

rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test
         robot)
         Added headroom/chunk size getter. (Maxim/Björn)

v1->v2: Swapped SoBs. (Maxim)

v2->v3: Initialize struct xdp_buff member frame_sz. (Björn)
        Add API to query the DMA address of a frame. (Maxim)
        Do DMA sync for CPU till the end of the frame to handle
        possible growth (frame_sz). (Maxim)

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com
2020-05-21 17:31:26 -07:00

382 lines
8.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Interface for implementing AF_XDP zero-copy support in drivers.
* Copyright(c) 2020 Intel Corporation.
*/
#ifndef _LINUX_XDP_SOCK_DRV_H
#define _LINUX_XDP_SOCK_DRV_H
#include <net/xdp_sock.h>
#include <net/xsk_buff_pool.h>
#ifdef CONFIG_XDP_SOCKETS
bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt);
bool xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr);
void xsk_umem_release_addr(struct xdp_umem *umem);
void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries);
bool xsk_umem_consume_tx(struct xdp_umem *umem, struct xdp_desc *desc);
void xsk_umem_consume_tx_done(struct xdp_umem *umem);
struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries);
struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
struct xdp_umem_fq_reuse *newq);
void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq);
struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev, u16 queue_id);
void xsk_set_rx_need_wakeup(struct xdp_umem *umem);
void xsk_set_tx_need_wakeup(struct xdp_umem *umem);
void xsk_clear_rx_need_wakeup(struct xdp_umem *umem);
void xsk_clear_tx_need_wakeup(struct xdp_umem *umem);
bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem);
static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
{
unsigned long page_addr;
addr = xsk_umem_add_offset_to_addr(addr);
page_addr = (unsigned long)umem->pages[addr >> PAGE_SHIFT].addr;
return (char *)(page_addr & PAGE_MASK) + (addr & ~PAGE_MASK);
}
static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
{
addr = xsk_umem_add_offset_to_addr(addr);
return umem->pages[addr >> PAGE_SHIFT].dma + (addr & ~PAGE_MASK);
}
/* Reuse-queue aware version of FILL queue helpers */
static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
{
struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
if (rq->length >= cnt)
return true;
return xsk_umem_has_addrs(umem, cnt - rq->length);
}
static inline bool xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
{
struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
if (!rq->length)
return xsk_umem_peek_addr(umem, addr);
*addr = rq->handles[rq->length - 1];
return addr;
}
static inline void xsk_umem_release_addr_rq(struct xdp_umem *umem)
{
struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
if (!rq->length)
xsk_umem_release_addr(umem);
else
rq->length--;
}
static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
{
struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
rq->handles[rq->length++] = addr;
}
/* Handle the offset appropriately depending on aligned or unaligned mode.
* For unaligned mode, we store the offset in the upper 16-bits of the address.
* For aligned mode, we simply add the offset to the address.
*/
static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address,
u64 offset)
{
if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG)
return address + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
else
return address + offset;
}
static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem)
{
return umem->chunk_size_nohr;
}
static inline u32 xsk_umem_get_headroom(struct xdp_umem *umem)
{
return XDP_PACKET_HEADROOM + umem->headroom;
}
static inline u32 xsk_umem_get_chunk_size(struct xdp_umem *umem)
{
return umem->chunk_size;
}
static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem)
{
return xsk_umem_get_chunk_size(umem) - xsk_umem_get_headroom(umem);
}
static inline void xsk_buff_set_rxq_info(struct xdp_umem *umem,
struct xdp_rxq_info *rxq)
{
xp_set_rxq_info(umem->pool, rxq);
}
static inline void xsk_buff_dma_unmap(struct xdp_umem *umem,
unsigned long attrs)
{
xp_dma_unmap(umem->pool, attrs);
}
static inline int xsk_buff_dma_map(struct xdp_umem *umem, struct device *dev,
unsigned long attrs)
{
return xp_dma_map(umem->pool, dev, attrs, umem->pgs, umem->npgs);
}
static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
return xp_get_dma(xskb);
}
static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
return xp_get_frame_dma(xskb);
}
static inline struct xdp_buff *xsk_buff_alloc(struct xdp_umem *umem)
{
return xp_alloc(umem->pool);
}
static inline bool xsk_buff_can_alloc(struct xdp_umem *umem, u32 count)
{
return xp_can_alloc(umem->pool, count);
}
static inline void xsk_buff_free(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
xp_free(xskb);
}
static inline dma_addr_t xsk_buff_raw_get_dma(struct xdp_umem *umem, u64 addr)
{
return xp_raw_get_dma(umem->pool, addr);
}
static inline void *xsk_buff_raw_get_data(struct xdp_umem *umem, u64 addr)
{
return xp_raw_get_data(umem->pool, addr);
}
static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
{
struct xdp_buff_xsk *xskb = container_of(xdp, struct xdp_buff_xsk, xdp);
xp_dma_sync_for_cpu(xskb);
}
static inline void xsk_buff_raw_dma_sync_for_device(struct xdp_umem *umem,
dma_addr_t dma,
size_t size)
{
xp_dma_sync_for_device(umem->pool, dma, size);
}
#else
static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
{
return false;
}
static inline u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
{
return NULL;
}
static inline void xsk_umem_release_addr(struct xdp_umem *umem)
{
}
static inline void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
{
}
static inline bool xsk_umem_consume_tx(struct xdp_umem *umem,
struct xdp_desc *desc)
{
return false;
}
static inline void xsk_umem_consume_tx_done(struct xdp_umem *umem)
{
}
static inline struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
{
return NULL;
}
static inline struct xdp_umem_fq_reuse *xsk_reuseq_swap(
struct xdp_umem *umem, struct xdp_umem_fq_reuse *newq)
{
return NULL;
}
static inline void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
{
}
static inline struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,
u16 queue_id)
{
return NULL;
}
static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
{
return NULL;
}
static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
{
return 0;
}
static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
{
return false;
}
static inline u64 *xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
{
return NULL;
}
static inline void xsk_umem_release_addr_rq(struct xdp_umem *umem)
{
}
static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
{
}
static inline void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
{
}
static inline void xsk_set_tx_need_wakeup(struct xdp_umem *umem)
{
}
static inline void xsk_clear_rx_need_wakeup(struct xdp_umem *umem)
{
}
static inline void xsk_clear_tx_need_wakeup(struct xdp_umem *umem)
{
}
static inline bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
{
return false;
}
static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle,
u64 offset)
{
return 0;
}
static inline u32 xsk_umem_xdp_frame_sz(struct xdp_umem *umem)
{
return 0;
}
static inline u32 xsk_umem_get_headroom(struct xdp_umem *umem)
{
return 0;
}
static inline u32 xsk_umem_get_chunk_size(struct xdp_umem *umem)
{
return 0;
}
static inline u32 xsk_umem_get_rx_frame_size(struct xdp_umem *umem)
{
return 0;
}
static inline void xsk_buff_set_rxq_info(struct xdp_umem *umem,
struct xdp_rxq_info *rxq)
{
}
static inline void xsk_buff_dma_unmap(struct xdp_umem *umem,
unsigned long attrs)
{
}
static inline int xsk_buff_dma_map(struct xdp_umem *umem, struct device *dev,
unsigned long attrs)
{
return 0;
}
static inline dma_addr_t xsk_buff_xdp_get_dma(struct xdp_buff *xdp)
{
return 0;
}
static inline dma_addr_t xsk_buff_xdp_get_frame_dma(struct xdp_buff *xdp)
{
return 0;
}
static inline struct xdp_buff *xsk_buff_alloc(struct xdp_umem *umem)
{
return NULL;
}
static inline bool xsk_buff_can_alloc(struct xdp_umem *umem, u32 count)
{
return false;
}
static inline void xsk_buff_free(struct xdp_buff *xdp)
{
}
static inline dma_addr_t xsk_buff_raw_get_dma(struct xdp_umem *umem, u64 addr)
{
return 0;
}
static inline void *xsk_buff_raw_get_data(struct xdp_umem *umem, u64 addr)
{
return NULL;
}
static inline void xsk_buff_dma_sync_for_cpu(struct xdp_buff *xdp)
{
}
static inline void xsk_buff_raw_dma_sync_for_device(struct xdp_umem *umem,
dma_addr_t dma,
size_t size)
{
}
#endif /* CONFIG_XDP_SOCKETS */
#endif /* _LINUX_XDP_SOCK_DRV_H */