xref: /openbmc/linux/include/net/xdp_sock.h (revision ecd25094)
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 struct xsk_map;
73 struct xsk_map_node {
74 	struct list_head node;
75 	struct xsk_map *map;
76 	struct xdp_sock **map_entry;
77 };
78 
79 struct xdp_sock {
80 	/* struct sock must be the first member of struct xdp_sock */
81 	struct sock sk;
82 	struct xsk_queue *rx;
83 	struct net_device *dev;
84 	struct xdp_umem *umem;
85 	struct list_head flush_node;
86 	u16 queue_id;
87 	bool zc;
88 	enum {
89 		XSK_READY = 0,
90 		XSK_BOUND,
91 		XSK_UNBOUND,
92 	} state;
93 	/* Protects multiple processes in the control path */
94 	struct mutex mutex;
95 	struct xsk_queue *tx ____cacheline_aligned_in_smp;
96 	struct list_head list;
97 	/* Mutual exclusion of NAPI TX thread and sendmsg error paths
98 	 * in the SKB destructor callback.
99 	 */
100 	spinlock_t tx_completion_lock;
101 	/* Protects generic receive. */
102 	spinlock_t rx_lock;
103 	u64 rx_dropped;
104 	struct list_head map_list;
105 	/* Protects map_list */
106 	spinlock_t map_list_lock;
107 };
108 
109 struct xdp_buff;
110 #ifdef CONFIG_XDP_SOCKETS
111 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
112 int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
113 void xsk_flush(struct xdp_sock *xs);
114 bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
115 /* Used from netdev driver */
116 bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt);
117 u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr);
118 void xsk_umem_discard_addr(struct xdp_umem *umem);
119 void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries);
120 bool xsk_umem_consume_tx(struct xdp_umem *umem, struct xdp_desc *desc);
121 void xsk_umem_consume_tx_done(struct xdp_umem *umem);
122 struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries);
123 struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
124 					  struct xdp_umem_fq_reuse *newq);
125 void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq);
126 struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev, u16 queue_id);
127 void xsk_set_rx_need_wakeup(struct xdp_umem *umem);
128 void xsk_set_tx_need_wakeup(struct xdp_umem *umem);
129 void xsk_clear_rx_need_wakeup(struct xdp_umem *umem);
130 void xsk_clear_tx_need_wakeup(struct xdp_umem *umem);
131 bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem);
132 
133 void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
134 			     struct xdp_sock **map_entry);
135 int xsk_map_inc(struct xsk_map *map);
136 void xsk_map_put(struct xsk_map *map);
137 
138 static inline u64 xsk_umem_extract_addr(u64 addr)
139 {
140 	return addr & XSK_UNALIGNED_BUF_ADDR_MASK;
141 }
142 
143 static inline u64 xsk_umem_extract_offset(u64 addr)
144 {
145 	return addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT;
146 }
147 
148 static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
149 {
150 	return xsk_umem_extract_addr(addr) + xsk_umem_extract_offset(addr);
151 }
152 
153 static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
154 {
155 	unsigned long page_addr;
156 
157 	addr = xsk_umem_add_offset_to_addr(addr);
158 	page_addr = (unsigned long)umem->pages[addr >> PAGE_SHIFT].addr;
159 
160 	return (char *)(page_addr & PAGE_MASK) + (addr & ~PAGE_MASK);
161 }
162 
163 static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
164 {
165 	addr = xsk_umem_add_offset_to_addr(addr);
166 
167 	return umem->pages[addr >> PAGE_SHIFT].dma + (addr & ~PAGE_MASK);
168 }
169 
170 /* Reuse-queue aware version of FILL queue helpers */
171 static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
172 {
173 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
174 
175 	if (rq->length >= cnt)
176 		return true;
177 
178 	return xsk_umem_has_addrs(umem, cnt - rq->length);
179 }
180 
181 static inline u64 *xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
182 {
183 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
184 
185 	if (!rq->length)
186 		return xsk_umem_peek_addr(umem, addr);
187 
188 	*addr = rq->handles[rq->length - 1];
189 	return addr;
190 }
191 
192 static inline void xsk_umem_discard_addr_rq(struct xdp_umem *umem)
193 {
194 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
195 
196 	if (!rq->length)
197 		xsk_umem_discard_addr(umem);
198 	else
199 		rq->length--;
200 }
201 
202 static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
203 {
204 	struct xdp_umem_fq_reuse *rq = umem->fq_reuse;
205 
206 	rq->handles[rq->length++] = addr;
207 }
208 
209 /* Handle the offset appropriately depending on aligned or unaligned mode.
210  * For unaligned mode, we store the offset in the upper 16-bits of the address.
211  * For aligned mode, we simply add the offset to the address.
212  */
213 static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 address,
214 					 u64 offset)
215 {
216 	if (umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG)
217 		return address + (offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT);
218 	else
219 		return address + offset;
220 }
221 #else
222 static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
223 {
224 	return -ENOTSUPP;
225 }
226 
227 static inline int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
228 {
229 	return -ENOTSUPP;
230 }
231 
232 static inline void xsk_flush(struct xdp_sock *xs)
233 {
234 }
235 
236 static inline bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
237 {
238 	return false;
239 }
240 
241 static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
242 {
243 	return false;
244 }
245 
246 static inline u64 *xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr)
247 {
248 	return NULL;
249 }
250 
251 static inline void xsk_umem_discard_addr(struct xdp_umem *umem)
252 {
253 }
254 
255 static inline void xsk_umem_complete_tx(struct xdp_umem *umem, u32 nb_entries)
256 {
257 }
258 
259 static inline bool xsk_umem_consume_tx(struct xdp_umem *umem,
260 				       struct xdp_desc *desc)
261 {
262 	return false;
263 }
264 
265 static inline void xsk_umem_consume_tx_done(struct xdp_umem *umem)
266 {
267 }
268 
269 static inline struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
270 {
271 	return NULL;
272 }
273 
274 static inline struct xdp_umem_fq_reuse *xsk_reuseq_swap(
275 	struct xdp_umem *umem,
276 	struct xdp_umem_fq_reuse *newq)
277 {
278 	return NULL;
279 }
280 static inline void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
281 {
282 }
283 
284 static inline struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,
285 						     u16 queue_id)
286 {
287 	return NULL;
288 }
289 
290 static inline u64 xsk_umem_extract_addr(u64 addr)
291 {
292 	return 0;
293 }
294 
295 static inline u64 xsk_umem_extract_offset(u64 addr)
296 {
297 	return 0;
298 }
299 
300 static inline u64 xsk_umem_add_offset_to_addr(u64 addr)
301 {
302 	return 0;
303 }
304 
305 static inline char *xdp_umem_get_data(struct xdp_umem *umem, u64 addr)
306 {
307 	return NULL;
308 }
309 
310 static inline dma_addr_t xdp_umem_get_dma(struct xdp_umem *umem, u64 addr)
311 {
312 	return 0;
313 }
314 
315 static inline bool xsk_umem_has_addrs_rq(struct xdp_umem *umem, u32 cnt)
316 {
317 	return false;
318 }
319 
320 static inline u64 *xsk_umem_peek_addr_rq(struct xdp_umem *umem, u64 *addr)
321 {
322 	return NULL;
323 }
324 
325 static inline void xsk_umem_discard_addr_rq(struct xdp_umem *umem)
326 {
327 }
328 
329 static inline void xsk_umem_fq_reuse(struct xdp_umem *umem, u64 addr)
330 {
331 }
332 
333 static inline void xsk_set_rx_need_wakeup(struct xdp_umem *umem)
334 {
335 }
336 
337 static inline void xsk_set_tx_need_wakeup(struct xdp_umem *umem)
338 {
339 }
340 
341 static inline void xsk_clear_rx_need_wakeup(struct xdp_umem *umem)
342 {
343 }
344 
345 static inline void xsk_clear_tx_need_wakeup(struct xdp_umem *umem)
346 {
347 }
348 
349 static inline bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem)
350 {
351 	return false;
352 }
353 
354 static inline u64 xsk_umem_adjust_offset(struct xdp_umem *umem, u64 handle,
355 					 u64 offset)
356 {
357 	return 0;
358 }
359 
360 #endif /* CONFIG_XDP_SOCKETS */
361 
362 #endif /* _LINUX_XDP_SOCK_H */
363