linux/include/net/xsk_buff_pool.h
Magnus Karlsson 94033cd8e7 xsk: Optimize for aligned case
Optimize for the aligned case by precomputing the parameter values of
the xdp_buff_xsk and xdp_buff structures in the heads array. We can do
this as the heads array size is equal to the number of chunks in the
umem for the aligned case. Then every entry in this array will reflect
a certain chunk/frame and can therefore be prepopulated with the
correct values and we can drop the use of the free_heads stack. Note
that it is not possible to allocate more buffers than what has been
allocated in the aligned case since each chunk can only contain a
single buffer.

We can unfortunately not do this in the unaligned case as one chunk
might contain multiple buffers. In this case, we keep the old scheme
of populating a heads entry every time it is used and using
the free_heads stack.

Also move xp_release() and xp_get_handle() to xsk_buff_pool.h. They
were for some reason in xsk.c even though they are buffer pool
operations.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922075613.12186-7-magnus.karlsson@gmail.com
2021-09-28 00:18:35 +02:00

228 lines
6.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright(c) 2020 Intel Corporation. */
#ifndef XSK_BUFF_POOL_H_
#define XSK_BUFF_POOL_H_
#include <linux/if_xdp.h>
#include <linux/types.h>
#include <linux/dma-mapping.h>
#include <linux/bpf.h>
#include <net/xdp.h>
struct xsk_buff_pool;
struct xdp_rxq_info;
struct xsk_queue;
struct xdp_desc;
struct xdp_umem;
struct xdp_sock;
struct device;
struct page;
struct xdp_buff_xsk {
struct xdp_buff xdp;
dma_addr_t dma;
dma_addr_t frame_dma;
struct xsk_buff_pool *pool;
u64 orig_addr;
struct list_head free_list_node;
};
struct xsk_dma_map {
dma_addr_t *dma_pages;
struct device *dev;
struct net_device *netdev;
refcount_t users;
struct list_head list; /* Protected by the RTNL_LOCK */
u32 dma_pages_cnt;
bool dma_need_sync;
};
struct xsk_buff_pool {
/* Members only used in the control path first. */
struct device *dev;
struct net_device *netdev;
struct list_head xsk_tx_list;
/* Protects modifications to the xsk_tx_list */
spinlock_t xsk_tx_list_lock;
refcount_t users;
struct xdp_umem *umem;
struct work_struct work;
struct list_head free_list;
u32 heads_cnt;
u16 queue_id;
/* Data path members as close to free_heads at the end as possible. */
struct xsk_queue *fq ____cacheline_aligned_in_smp;
struct xsk_queue *cq;
/* For performance reasons, each buff pool has its own array of dma_pages
* even when they are identical.
*/
dma_addr_t *dma_pages;
struct xdp_buff_xsk *heads;
u64 chunk_mask;
u64 addrs_cnt;
u32 free_list_cnt;
u32 dma_pages_cnt;
u32 free_heads_cnt;
u32 headroom;
u32 chunk_size;
u32 chunk_shift;
u32 frame_len;
u8 cached_need_wakeup;
bool uses_need_wakeup;
bool dma_need_sync;
bool unaligned;
void *addrs;
/* Mutual exclusion of the completion ring in the SKB mode. Two cases to protect:
* NAPI TX thread and sendmsg error paths in the SKB destructor callback and when
* sockets share a single cq when the same netdev and queue id is shared.
*/
spinlock_t cq_lock;
struct xdp_buff_xsk *free_heads[];
};
/* Masks for xdp_umem_page flags.
* The low 12-bits of the addr will be 0 since this is the page address, so we
* can use them for flags.
*/
#define XSK_NEXT_PG_CONTIG_SHIFT 0
#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
/* AF_XDP core. */
struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
struct xdp_umem *umem);
int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
u16 queue_id, u16 flags);
int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem,
struct net_device *dev, u16 queue_id);
void xp_destroy(struct xsk_buff_pool *pool);
void xp_get_pool(struct xsk_buff_pool *pool);
bool xp_put_pool(struct xsk_buff_pool *pool);
void xp_clear_dev(struct xsk_buff_pool *pool);
void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
/* AF_XDP, and XDP core. */
void xp_free(struct xdp_buff_xsk *xskb);
static inline void xp_init_xskb_addr(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
u64 addr)
{
xskb->orig_addr = addr;
xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
}
static inline void xp_init_xskb_dma(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
dma_addr_t *dma_pages, u64 addr)
{
xskb->frame_dma = (dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) +
(addr & ~PAGE_MASK);
xskb->dma = xskb->frame_dma + pool->headroom + XDP_PACKET_HEADROOM;
}
/* AF_XDP ZC drivers, via xdp_sock_buff.h */
void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq);
int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
unsigned long attrs, struct page **pages, u32 nr_pages);
void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs);
struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool);
u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max);
bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count);
void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr);
dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr);
static inline dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb)
{
return xskb->dma;
}
static inline dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb)
{
return xskb->frame_dma;
}
void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb);
static inline void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
{
xp_dma_sync_for_cpu_slow(xskb);
}
void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
size_t size);
static inline void xp_dma_sync_for_device(struct xsk_buff_pool *pool,
dma_addr_t dma, size_t size)
{
if (!pool->dma_need_sync)
return;
xp_dma_sync_for_device_slow(pool, dma, size);
}
/* Masks for xdp_umem_page flags.
* The low 12-bits of the addr will be 0 since this is the page address, so we
* can use them for flags.
*/
#define XSK_NEXT_PG_CONTIG_SHIFT 0
#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool,
u64 addr, u32 len)
{
bool cross_pg = (addr & (PAGE_SIZE - 1)) + len > PAGE_SIZE;
if (likely(!cross_pg))
return false;
if (pool->dma_pages_cnt) {
return !(pool->dma_pages[addr >> PAGE_SHIFT] &
XSK_NEXT_PG_CONTIG_MASK);
}
/* skb path */
return addr + len > pool->addrs_cnt;
}
static inline u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr)
{
return addr & pool->chunk_mask;
}
static inline u64 xp_unaligned_extract_addr(u64 addr)
{
return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
}
static inline u64 xp_unaligned_extract_offset(u64 addr)
{
return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
}
static inline u64 xp_unaligned_add_offset_to_addr(u64 addr)
{
return xp_unaligned_extract_addr(addr) +
xp_unaligned_extract_offset(addr);
}
static inline u32 xp_aligned_extract_idx(struct xsk_buff_pool *pool, u64 addr)
{
return xp_aligned_extract_addr(pool, addr) >> pool->chunk_shift;
}
static inline void xp_release(struct xdp_buff_xsk *xskb)
{
if (xskb->pool->unaligned)
xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
}
static inline u64 xp_get_handle(struct xdp_buff_xsk *xskb)
{
u64 offset = xskb->xdp.data - xskb->xdp.data_hard_start;
offset += xskb->pool->headroom;
if (!xskb->pool->unaligned)
return xskb->orig_addr + offset;
return xskb->orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
}
#endif /* XSK_BUFF_POOL_H_ */