xsk_buff_pool.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/* Copyright(c) 2020 Intel Corporation. */
  3
  4#ifndef XSK_BUFF_POOL_H_
  5#define XSK_BUFF_POOL_H_
  6
  7#include <linux/if_xdp.h>
  8#include <linux/types.h>
  9#include <linux/dma-mapping.h>
 10#include <linux/bpf.h>
 11#include <net/xdp.h>
 12
 13struct xsk_buff_pool;
 14struct xdp_rxq_info;
 15struct xsk_cb_desc;
 16struct xsk_queue;
 17struct xdp_desc;
 18struct xdp_umem;
 19struct xdp_sock;
 20struct device;
 21struct page;
 22
 23#define XSK_PRIV_MAX 24
 24
 25struct xdp_buff_xsk {
 26	struct xdp_buff xdp;
 27	u8 cb[XSK_PRIV_MAX];
 28	dma_addr_t dma;
 29	dma_addr_t frame_dma;
 30	struct xsk_buff_pool *pool;
 31	struct list_head list_node;
 32} __aligned_largest;
 33
 34#define XSK_CHECK_PRIV_TYPE(t) BUILD_BUG_ON(sizeof(t) > offsetofend(struct xdp_buff_xsk, cb))
 35#define XSK_TX_COMPL_FITS(t) BUILD_BUG_ON(sizeof(struct xsk_tx_metadata_compl) > sizeof(t))
 36
 37struct xsk_dma_map {
 38	dma_addr_t *dma_pages;
 39	struct device *dev;
 40	struct net_device *netdev;
 41	refcount_t users;
 42	struct list_head list; /* Protected by the RTNL_LOCK */
 43	u32 dma_pages_cnt;
 44};
 45
 46struct xsk_buff_pool {
 47	/* Members only used in the control path first. */
 48	struct device *dev;
 49	struct net_device *netdev;
 50	struct list_head xsk_tx_list;
 51	/* Protects modifications to the xsk_tx_list */
 52	spinlock_t xsk_tx_list_lock;
 53	refcount_t users;
 54	struct xdp_umem *umem;
 55	struct work_struct work;
 56	/* Protects generic receive in shared and non-shared umem mode. */
 57	spinlock_t rx_lock;
 58	struct list_head free_list;
 59	struct list_head xskb_list;
 60	u32 heads_cnt;
 61	u16 queue_id;
 62
 63	/* Data path members as close to free_heads at the end as possible. */
 64	struct xsk_queue *fq ____cacheline_aligned_in_smp;
 65	struct xsk_queue *cq;
 66	/* For performance reasons, each buff pool has its own array of dma_pages
 67	 * even when they are identical.
 68	 */
 69	dma_addr_t *dma_pages;
 70	struct xdp_buff_xsk *heads;
 71	struct xdp_desc *tx_descs;
 72	u64 chunk_mask;
 73	u64 addrs_cnt;
 74	u32 free_list_cnt;
 75	u32 dma_pages_cnt;
 76	u32 free_heads_cnt;
 77	u32 headroom;
 78	u32 chunk_size;
 79	u32 chunk_shift;
 80	u32 frame_len;
 81	u32 xdp_zc_max_segs;
 82	u8 tx_metadata_len; /* inherited from umem */
 83	u8 cached_need_wakeup;
 84	bool uses_need_wakeup;
 85	bool unaligned;
 86	bool tx_sw_csum;
 87	void *addrs;
 88	/* Mutual exclusion of the completion ring in the SKB mode.
 89	 * Protect: NAPI TX thread and sendmsg error paths in the SKB
 90	 * destructor callback.
 91	 */
 92	spinlock_t cq_prod_lock;
 93	/* Mutual exclusion of the completion ring in the SKB mode.
 94	 * Protect: when sockets share a single cq when the same netdev
 95	 * and queue id is shared.
 96	 */
 97	spinlock_t cq_cached_prod_lock;
 98	struct xdp_buff_xsk *free_heads[];
 99};
100
101/* Masks for xdp_umem_page flags.
102 * The low 12-bits of the addr will be 0 since this is the page address, so we
103 * can use them for flags.
104 */
105#define XSK_NEXT_PG_CONTIG_SHIFT 0
106#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
107
108/* AF_XDP core. */
109struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
110						struct xdp_umem *umem);
111int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
112		  u16 queue_id, u16 flags);
113int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
114			 struct net_device *dev, u16 queue_id);
115int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs);
116void xp_destroy(struct xsk_buff_pool *pool);
117void xp_get_pool(struct xsk_buff_pool *pool);
118bool xp_put_pool(struct xsk_buff_pool *pool);
119void xp_clear_dev(struct xsk_buff_pool *pool);
120void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
121void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs);
122
123/* AF_XDP, and XDP core. */
124void xp_free(struct xdp_buff_xsk *xskb);
125
126static inline void xp_init_xskb_addr(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
127				     u64 addr)
128{
129	xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom;
130}
131
132static inline void xp_init_xskb_dma(struct xdp_buff_xsk *xskb, struct xsk_buff_pool *pool,
133				    dma_addr_t *dma_pages, u64 addr)
134{
135	xskb->frame_dma = (dma_pages[addr >> PAGE_SHIFT] & ~XSK_NEXT_PG_CONTIG_MASK) +
136		(addr & ~PAGE_MASK);
137	xskb->dma = xskb->frame_dma + pool->headroom + XDP_PACKET_HEADROOM;
138}
139
140/* AF_XDP ZC drivers, via xdp_sock_buff.h */
141void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq);
142void xp_fill_cb(struct xsk_buff_pool *pool, struct xsk_cb_desc *desc);
143int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
144	       unsigned long attrs, struct page **pages, u32 nr_pages);
145void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs);
146struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool);
147u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max);
148bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count);
149void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr);
150dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr);
151
152struct xdp_desc_ctx {
153	dma_addr_t dma;
154	struct xsk_tx_metadata *meta;
155};
156
157struct xdp_desc_ctx xp_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr);
158
159static inline dma_addr_t xp_get_dma(struct xdp_buff_xsk *xskb)
160{
161	return xskb->dma;
162}
163
164static inline dma_addr_t xp_get_frame_dma(struct xdp_buff_xsk *xskb)
165{
166	return xskb->frame_dma;
167}
168
169static inline void xp_dma_sync_for_cpu(struct xdp_buff_xsk *xskb)
170{
171	dma_sync_single_for_cpu(xskb->pool->dev, xskb->dma,
172				xskb->pool->frame_len,
173				DMA_BIDIRECTIONAL);
174}
175
176static inline void xp_dma_sync_for_device(struct xsk_buff_pool *pool,
177					  dma_addr_t dma, size_t size)
178{
179	dma_sync_single_for_device(pool->dev, dma, size, DMA_BIDIRECTIONAL);
180}
181
182/* Masks for xdp_umem_page flags.
183 * The low 12-bits of the addr will be 0 since this is the page address, so we
184 * can use them for flags.
185 */
186#define XSK_NEXT_PG_CONTIG_SHIFT 0
187#define XSK_NEXT_PG_CONTIG_MASK BIT_ULL(XSK_NEXT_PG_CONTIG_SHIFT)
188
189static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool,
190						 u64 addr, u32 len)
191{
192	bool cross_pg = (addr & (PAGE_SIZE - 1)) + len > PAGE_SIZE;
193
194	if (likely(!cross_pg))
195		return false;
196
197	return pool->dma_pages &&
198	       !(pool->dma_pages[addr >> PAGE_SHIFT] & XSK_NEXT_PG_CONTIG_MASK);
199}
200
201static inline bool xp_mb_desc(const struct xdp_desc *desc)
202{
203	return desc->options & XDP_PKT_CONTD;
204}
205
206static inline u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr)
207{
208	return addr & pool->chunk_mask;
209}
210
211static inline u64 xp_unaligned_extract_addr(u64 addr)
212{
213	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
214}
215
216static inline u64 xp_unaligned_extract_offset(u64 addr)
217{
218	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
219}
220
221static inline u64 xp_unaligned_add_offset_to_addr(u64 addr)
222{
223	return xp_unaligned_extract_addr(addr) +
224		xp_unaligned_extract_offset(addr);
225}
226
227static inline u32 xp_aligned_extract_idx(struct xsk_buff_pool *pool, u64 addr)
228{
229	return xp_aligned_extract_addr(pool, addr) >> pool->chunk_shift;
230}
231
232static inline void xp_release(struct xdp_buff_xsk *xskb)
233{
234	if (xskb->pool->unaligned)
235		xskb->pool->free_heads[xskb->pool->free_heads_cnt++] = xskb;
236}
237
238static inline u64 xp_get_handle(struct xdp_buff_xsk *xskb,
239				struct xsk_buff_pool *pool)
240{
241	u64 orig_addr = xskb->xdp.data - pool->addrs;
242	u64 offset;
243
244	if (!pool->unaligned)
245		return orig_addr;
246
247	offset = xskb->xdp.data - xskb->xdp.data_hard_start;
248	offset += pool->headroom;
249	orig_addr -= offset;
250	return orig_addr + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
251}
252
253static inline bool xp_tx_metadata_enabled(const struct xsk_buff_pool *pool)
254{
255	return pool->tx_metadata_len > 0;
256}
257
258#endif /* XSK_BUFF_POOL_H_ */