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_ */
247

source code of linux/include/net/xsk_buff_pool.h