include/net/xsk_buff_pool.h - linux - Git at Google

 /* 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;

 #define XSK_PRIV_MAX 24

 struct xdp_buff_xsk {
 	struct xdp_buff xdp;
 	u8 cb[XSK_PRIV_MAX];
 	dma_addr_t dma;
 	dma_addr_t frame_dma;
 	struct xsk_buff_pool *pool;
 	u64 orig_addr;
 	struct list_head free_list_node;
 };

 #define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb))

 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;
 	struct xdp_desc *tx_descs;
 	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_sock *umem_xs,
 			 struct net_device *dev, u16 queue_id);
 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs);
 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;

 	return pool->dma_pages_cnt &&
 	       !(pool->dma_pages[addr >> PAGE_SHIFT] & XSK_NEXT_PG_CONTIG_MASK);
 }

 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_ */
	/* 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;

	#define XSK_PRIV_MAX 24

	struct xdp_buff_xsk {
	struct xdp_buff xdp;
	u8 cb[XSK_PRIV_MAX];
	dma_addr_t dma;
	dma_addr_t frame_dma;
	struct xsk_buff_pool *pool;
	u64 orig_addr;
	struct list_head free_list_node;
	};

	#define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb))

	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;
	struct xdp_desc *tx_descs;
	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_sock umem_xs,
	struct net_device *dev, u16 queue_id);
	int xp_alloc_tx_descs(struct xsk_buff_pool pool, struct xdp_sock xs);
	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;

	return pool->dma_pages_cnt &&
	!(pool->dma_pages[addr >> PAGE_SHIFT] & XSK_NEXT_PG_CONTIG_MASK);
	}

	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_ */