xref: /openbmc/linux/include/net/xdp_sock.h (revision f9834f18)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* AF_XDP internal functions
3  * Copyright(c) 2018 Intel Corporation.
4  */
5 
6 #ifndef _LINUX_XDP_SOCK_H
7 #define _LINUX_XDP_SOCK_H
8 
9 #include <linux/workqueue.h>
10 #include <linux/if_xdp.h>
11 #include <linux/mutex.h>
12 #include <linux/spinlock.h>
13 #include <linux/mm.h>
14 #include <net/sock.h>
15 
16 struct net_device;
17 struct xsk_queue;
18 
19 /* Masks for xdp_umem_page flags.
20  * The low 12-bits of the addr will be 0 since this is the page address, so we
21  * can use them for flags.
22  */
23 #define XSK_NEXT_PG_CONTIG_SHIFT 0
24 #define XSK_NEXT_PG_CONTIG_MASK (1ULL << XSK_NEXT_PG_CONTIG_SHIFT)
25 
26 struct xdp_umem_page {
27 	void *addr;
28 	dma_addr_t dma;
29 };
30 
31 struct xdp_umem_fq_reuse {
32 	u32 nentries;
33 	u32 length;
34 	u64 handles[];
35 };
36 
37 /* Flags for the umem flags field.
38  *
39  * The NEED_WAKEUP flag is 1 due to the reuse of the flags field for public
40  * flags. See inlude/uapi/include/linux/if_xdp.h.
41  */
42 #define XDP_UMEM_USES_NEED_WAKEUP (1 << 1)
43 
44 struct xdp_umem {
45 	struct xsk_queue *fq;
46 	struct xsk_queue *cq;
47 	struct xdp_umem_page *pages;
48 	u64 chunk_mask;
49 	u64 size;
50 	u32 headroom;
51 	u32 chunk_size_nohr;
52 	struct user_struct *user;
53 	unsigned long address;
54 	refcount_t users;
55 	struct work_struct work;
56 	struct page **pgs;
57 	u32 npgs;
58 	u16 queue_id;
59 	u8 need_wakeup;
60 	u8 flags;
61 	int id;
62 	struct net_device *dev;
63 	struct xdp_umem_fq_reuse *fq_reuse;
64 	bool zc;
65 	spinlock_t xsk_list_lock;
66 	struct list_head xsk_list;
67 };
68 
69 /* Nodes are linked in the struct xdp_sock map_list field, and used to
70  * track which maps a certain socket reside in.
71  */
72 
73 struct xsk_map {
74 	struct bpf_map map;
75 	spinlock_t lock; /* Synchronize map updates */
76 	struct xdp_sock *xsk_map[];
77 };
78 
79 struct xsk_map_node {
80 	struct list_head node;
81 	struct xsk_map *map;
82 	struct xdp_sock **map_entry;
83 };
84 
85 struct xdp_sock {
86 	/* struct sock must be the first member of struct xdp_sock */
87 	struct sock sk;
88 	struct xsk_queue *rx;
89 	struct net_device *dev;
90 	struct xdp_umem *umem;
91 	struct list_head flush_node;
92 	u16 queue_id;
93 	bool zc;
94 	enum {
95 		XSK_READY = 0,
96 		XSK_BOUND,
97 		XSK_UNBOUND,
98 	} state;
99 	/* Protects multiple processes in the control path */
100 	struct mutex mutex;
101 	struct xsk_queue *tx ____cacheline_aligned_in_smp;
102 	struct list_head list;
103 	/* Mutual exclusion of NAPI TX thread and sendmsg error paths
104 	 * in the SKB destructor callback.
105 	 */
106 	spinlock_t tx_completion_lock;
107 	/* Protects generic receive. */
108 	spinlock_t rx_lock;
109 	u64 rx_dropped;
110 	struct list_head map_list;
111 	/* Protects map_list */
112 	spinlock_t map_list_lock;
113 };
114 
115 struct xdp_buff;
116 #ifdef CONFIG_XDP_SOCKETS
117 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
118 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
119 /* Used from netdev driver */
120 bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt);
121 bool xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr);
122 void xsk_umem_release_addr(struct xdp_umem *umem);
123 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries);
124 bool xsk_umem_consume_tx(struct xdp_umem *umem, struct xdp_desc *desc);
125 void xsk_umem_consume_tx_done(struct xdp_umem *umem);
126 struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries);
127 struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
128 					  struct xdp_umem_fq_reuse *newq);
129 void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq);
130 struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev, u16 queue_id);
131 void xsk_set_rx_need_wakeup(struct xdp_umem *umem);
132 void xsk_set_tx_need_wakeup(struct xdp_umem *umem);
133 void xsk_clear_rx_need_wakeup(struct xdp_umem *umem);
134 void xsk_clear_tx_need_wakeup(struct xdp_umem *umem);
135 bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem);
136 
137 void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
138 			     struct xdp_sock **map_entry);
139 int xsk_map_inc(struct xsk_map *map);
140 void xsk_map_put(struct xsk_map *map);
141 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
142 void __xsk_map_flush(void);
143 
144 static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
145 						     u32 key)
146 {
147 	struct xsk_map *m = container_of(map, struct xsk_map, map);
148 	struct xdp_sock *xs;
149 
150 	if (key >= map->max_entries)
151 		return NULL;
152 
153 	xs = READ_ONCE(m->xsk_map[key]);
154 	return xs;
155 }
156 
157 static inline u64 xsk_umem_extract_addr(u64 addr)
158 {
159 	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
160 }
161 
162 static inline u64 xsk_umem_extract_offset(u64 addr)
163 {
164 	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
165 }
166 
167 static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
168 {
169 	return xsk_umem_extract_addr(addr) + xsk_umem_extract_offset(addr);
170 }
171 
172 static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
173 {
174 	unsigned long page_addr;
175 
176 	addr = xsk_umem_add_offset_to_addr(addr);
177 	page_addr = (unsigned long)umem->pages[addr >> PAGE_SHIFT].addr;
178 
179 	return (char *)(page_addr & PAGE_MASK) + (addr & ~PAGE_MASK);
180 }
181 
182 static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
183 {
184 	addr = xsk_umem_add_offset_to_addr(addr);
185 
186 	return umem->pages[addr >> PAGE_SHIFT].dma + (addr & ~PAGE_MASK);
187 }
188 
189 /* Reuse-queue aware version of FILL queue helpers */
190 static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
191 {
192 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
193 
194 	if (rq->length >= cnt)
195 		return true;
196 
197 	return xsk_umem_has_addrs(umem, cnt - rq->length);
198 }
199 
200 static inline bool xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
201 {
202 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
203 
204 	if (!rq->length)
205 		return xsk_umem_peek_addr(umem, addr);
206 
207 	*addr = rq->handles[rq->length - 1];
208 	return addr;
209 }
210 
211 static inline void xsk_umem_release_addr_rq(struct xdp_umem *umem)
212 {
213 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
214 
215 	if (!rq->length)
216 		xsk_umem_release_addr(umem);
217 	else
218 		rq->length--;
219 }
220 
221 static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
222 {
223 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
224 
225 	rq->handles[rq->length++] = addr;
226 }
227 
228 /* Handle the offset appropriately depending on aligned or unaligned mode.
229  * For unaligned mode, we store the offset in the upper 16-bits of the address.
230  * For aligned mode, we simply add the offset to the address.
231  */
232 static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address,
233 					 u64 offset)
234 {
235 	if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG)
236 		return address + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
237 	else
238 		return address + offset;
239 }
240 #else
241 static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
242 {
243 	return -ENOTSUPP;
244 }
245 
246 static inline bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
247 {
248 	return false;
249 }
250 
251 static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
252 {
253 	return false;
254 }
255 
256 static inline u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
257 {
258 	return NULL;
259 }
260 
261 static inline void xsk_umem_release_addr(struct xdp_umem *umem)
262 {
263 }
264 
265 static inline void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
266 {
267 }
268 
269 static inline bool xsk_umem_consume_tx(struct xdp_umem *umem,
270 				       struct xdp_desc *desc)
271 {
272 	return false;
273 }
274 
275 static inline void xsk_umem_consume_tx_done(struct xdp_umem *umem)
276 {
277 }
278 
279 static inline struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
280 {
281 	return NULL;
282 }
283 
284 static inline struct xdp_umem_fq_reuse *xsk_reuseq_swap(
285 	struct xdp_umem *umem,
286 	struct xdp_umem_fq_reuse *newq)
287 {
288 	return NULL;
289 }
290 static inline void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
291 {
292 }
293 
294 static inline struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,
295 						     u16 queue_id)
296 {
297 	return NULL;
298 }
299 
300 static inline u64 xsk_umem_extract_addr(u64 addr)
301 {
302 	return 0;
303 }
304 
305 static inline u64 xsk_umem_extract_offset(u64 addr)
306 {
307 	return 0;
308 }
309 
310 static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
311 {
312 	return 0;
313 }
314 
315 static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
316 {
317 	return NULL;
318 }
319 
320 static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
321 {
322 	return 0;
323 }
324 
325 static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
326 {
327 	return false;
328 }
329 
330 static inline u64 *xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
331 {
332 	return NULL;
333 }
334 
335 static inline void xsk_umem_release_addr_rq(struct xdp_umem *umem)
336 {
337 }
338 
339 static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
340 {
341 }
342 
343 static inline void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
344 {
345 }
346 
347 static inline void xsk_set_tx_need_wakeup(struct xdp_umem *umem)
348 {
349 }
350 
351 static inline void xsk_clear_rx_need_wakeup(struct xdp_umem *umem)
352 {
353 }
354 
355 static inline void xsk_clear_tx_need_wakeup(struct xdp_umem *umem)
356 {
357 }
358 
359 static inline bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
360 {
361 	return false;
362 }
363 
364 static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle,
365 					 u64 offset)
366 {
367 	return 0;
368 }
369 
370 static inline int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp)
371 {
372 	return -EOPNOTSUPP;
373 }
374 
375 static inline void __xsk_map_flush(void)
376 {
377 }
378 
379 static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,
380 						     u32 key)
381 {
382 	return NULL;
383 }
384 #endif /* CONFIG_XDP_SOCKETS */
385 
386 #endif /* _LINUX_XDP_SOCK_H */
387