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