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ddc64d0a | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
aecd67b6 JDB |
2 | /* include/net/xdp.h |
3 | * | |
4 | * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc. | |
aecd67b6 JDB |
5 | */ |
6 | #ifndef __LINUX_NET_XDP_H__ | |
7 | #define __LINUX_NET_XDP_H__ | |
8 | ||
f95f0f95 JDB |
9 | #include <linux/skbuff.h> /* skb_shared_info */ |
10 | ||
aecd67b6 JDB |
11 | /** |
12 | * DOC: XDP RX-queue information | |
13 | * | |
14 | * The XDP RX-queue info (xdp_rxq_info) is associated with the driver | |
15 | * level RX-ring queues. It is information that is specific to how | |
16 | * the driver have configured a given RX-ring queue. | |
17 | * | |
18 | * Each xdp_buff frame received in the driver carry a (pointer) | |
19 | * reference to this xdp_rxq_info structure. This provides the XDP | |
20 | * data-path read-access to RX-info for both kernel and bpf-side | |
21 | * (limited subset). | |
22 | * | |
23 | * For now, direct access is only safe while running in NAPI/softirq | |
24 | * context. Contents is read-mostly and must not be updated during | |
25 | * driver NAPI/softirq poll. | |
26 | * | |
27 | * The driver usage API is a register and unregister API. | |
28 | * | |
29 | * The struct is not directly tied to the XDP prog. A new XDP prog | |
30 | * can be attached as long as it doesn't change the underlying | |
31 | * RX-ring. If the RX-ring does change significantly, the NIC driver | |
32 | * naturally need to stop the RX-ring before purging and reallocating | |
33 | * memory. In that process the driver MUST call unregistor (which | |
34 | * also apply for driver shutdown and unload). The register API is | |
35 | * also mandatory during RX-ring setup. | |
36 | */ | |
37 | ||
5ab073ff JDB |
38 | enum xdp_mem_type { |
39 | MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */ | |
40 | MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */ | |
57d0a1c1 | 41 | MEM_TYPE_PAGE_POOL, |
2b43470a | 42 | MEM_TYPE_XSK_BUFF_POOL, |
5ab073ff JDB |
43 | MEM_TYPE_MAX, |
44 | }; | |
45 | ||
42b33468 | 46 | /* XDP flags for ndo_xdp_xmit */ |
42b33468 JDB |
47 | #define XDP_XMIT_FLUSH (1U << 0) /* doorbell signal consumer */ |
48 | #define XDP_XMIT_FLAGS_MASK XDP_XMIT_FLUSH | |
49 | ||
5ab073ff JDB |
50 | struct xdp_mem_info { |
51 | u32 type; /* enum xdp_mem_type, but known size type */ | |
8d5d8852 | 52 | u32 id; |
5ab073ff JDB |
53 | }; |
54 | ||
57d0a1c1 JDB |
55 | struct page_pool; |
56 | ||
aecd67b6 JDB |
57 | struct xdp_rxq_info { |
58 | struct net_device *dev; | |
59 | u32 queue_index; | |
60 | u32 reg_state; | |
5ab073ff | 61 | struct xdp_mem_info mem; |
b02e5a0e | 62 | unsigned int napi_id; |
aecd67b6 JDB |
63 | } ____cacheline_aligned; /* perf critical, avoid false-sharing */ |
64 | ||
64b59025 DA |
65 | struct xdp_txq_info { |
66 | struct net_device *dev; | |
67 | }; | |
68 | ||
106ca27f JDB |
69 | struct xdp_buff { |
70 | void *data; | |
71 | void *data_end; | |
72 | void *data_meta; | |
73 | void *data_hard_start; | |
74 | struct xdp_rxq_info *rxq; | |
64b59025 | 75 | struct xdp_txq_info *txq; |
f95f0f95 | 76 | u32 frame_sz; /* frame size to deduce data_hard_end/reserved tailroom*/ |
106ca27f | 77 | }; |
5ab073ff | 78 | |
43b5169d LB |
79 | static __always_inline void |
80 | xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq) | |
81 | { | |
82 | xdp->frame_sz = frame_sz; | |
83 | xdp->rxq = rxq; | |
84 | } | |
85 | ||
be9df4af LB |
86 | static __always_inline void |
87 | xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start, | |
88 | int headroom, int data_len, const bool meta_valid) | |
89 | { | |
90 | unsigned char *data = hard_start + headroom; | |
91 | ||
92 | xdp->data_hard_start = hard_start; | |
93 | xdp->data = data; | |
94 | xdp->data_end = data + data_len; | |
95 | xdp->data_meta = meta_valid ? data : data + 1; | |
96 | } | |
97 | ||
f95f0f95 JDB |
98 | /* Reserve memory area at end-of data area. |
99 | * | |
100 | * This macro reserves tailroom in the XDP buffer by limiting the | |
101 | * XDP/BPF data access to data_hard_end. Notice same area (and size) | |
102 | * is used for XDP_PASS, when constructing the SKB via build_skb(). | |
103 | */ | |
104 | #define xdp_data_hard_end(xdp) \ | |
105 | ((xdp)->data_hard_start + (xdp)->frame_sz - \ | |
106 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) | |
107 | ||
2f0bc54b LB |
108 | static inline struct skb_shared_info * |
109 | xdp_get_shared_info_from_buff(struct xdp_buff *xdp) | |
110 | { | |
111 | return (struct skb_shared_info *)xdp_data_hard_end(xdp); | |
112 | } | |
113 | ||
c0048cff JDB |
114 | struct xdp_frame { |
115 | void *data; | |
116 | u16 len; | |
117 | u16 headroom; | |
34cc0b33 JDB |
118 | u32 metasize:8; |
119 | u32 frame_sz:24; | |
c0048cff JDB |
120 | /* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time, |
121 | * while mem info is valid on remote CPU. | |
122 | */ | |
123 | struct xdp_mem_info mem; | |
70280ed9 | 124 | struct net_device *dev_rx; /* used by cpumap */ |
c0048cff JDB |
125 | }; |
126 | ||
89653987 LB |
127 | #define XDP_BULK_QUEUE_SIZE 16 |
128 | struct xdp_frame_bulk { | |
129 | int count; | |
130 | void *xa; | |
131 | void *q[XDP_BULK_QUEUE_SIZE]; | |
132 | }; | |
133 | ||
134 | static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq) | |
135 | { | |
136 | /* bq->count will be zero'ed when bq->xa gets updated */ | |
137 | bq->xa = NULL; | |
138 | } | |
dee72f8a | 139 | |
2f0bc54b LB |
140 | static inline struct skb_shared_info * |
141 | xdp_get_shared_info_from_frame(struct xdp_frame *frame) | |
142 | { | |
143 | void *data_hard_start = frame->data - frame->headroom - sizeof(*frame); | |
144 | ||
145 | return (struct skb_shared_info *)(data_hard_start + frame->frame_sz - | |
146 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info))); | |
147 | } | |
148 | ||
92164774 | 149 | struct xdp_cpumap_stats { |
28b1520e | 150 | unsigned int redirect; |
92164774 LB |
151 | unsigned int pass; |
152 | unsigned int drop; | |
153 | }; | |
154 | ||
a8d5b4ab TM |
155 | /* Clear kernel pointers in xdp_frame */ |
156 | static inline void xdp_scrub_frame(struct xdp_frame *frame) | |
157 | { | |
158 | frame->data = NULL; | |
159 | frame->dev_rx = NULL; | |
160 | } | |
161 | ||
34cc0b33 JDB |
162 | /* Avoids inlining WARN macro in fast-path */ |
163 | void xdp_warn(const char *msg, const char *func, const int line); | |
164 | #define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__) | |
165 | ||
b0d1beef BT |
166 | struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp); |
167 | ||
fc379872 LB |
168 | static inline |
169 | void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp) | |
170 | { | |
171 | xdp->data_hard_start = frame->data - frame->headroom - sizeof(*frame); | |
172 | xdp->data = frame->data; | |
173 | xdp->data_end = frame->data + frame->len; | |
174 | xdp->data_meta = frame->data - frame->metasize; | |
175 | xdp->frame_sz = frame->frame_sz; | |
176 | } | |
177 | ||
c0048cff | 178 | static inline |
daa5cdc3 DA |
179 | int xdp_update_frame_from_buff(struct xdp_buff *xdp, |
180 | struct xdp_frame *xdp_frame) | |
c0048cff | 181 | { |
daa5cdc3 | 182 | int metasize, headroom; |
02b55e56 | 183 | |
c0048cff JDB |
184 | /* Assure headroom is available for storing info */ |
185 | headroom = xdp->data - xdp->data_hard_start; | |
186 | metasize = xdp->data - xdp->data_meta; | |
187 | metasize = metasize > 0 ? metasize : 0; | |
188 | if (unlikely((headroom - metasize) < sizeof(*xdp_frame))) | |
daa5cdc3 | 189 | return -ENOSPC; |
c0048cff | 190 | |
34cc0b33 JDB |
191 | /* Catch if driver didn't reserve tailroom for skb_shared_info */ |
192 | if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) { | |
193 | XDP_WARN("Driver BUG: missing reserved tailroom"); | |
daa5cdc3 | 194 | return -ENOSPC; |
34cc0b33 JDB |
195 | } |
196 | ||
c0048cff JDB |
197 | xdp_frame->data = xdp->data; |
198 | xdp_frame->len = xdp->data_end - xdp->data; | |
199 | xdp_frame->headroom = headroom - sizeof(*xdp_frame); | |
200 | xdp_frame->metasize = metasize; | |
34cc0b33 | 201 | xdp_frame->frame_sz = xdp->frame_sz; |
c0048cff | 202 | |
daa5cdc3 DA |
203 | return 0; |
204 | } | |
205 | ||
206 | /* Convert xdp_buff to xdp_frame */ | |
207 | static inline | |
208 | struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp) | |
209 | { | |
210 | struct xdp_frame *xdp_frame; | |
211 | ||
212 | if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) | |
213 | return xdp_convert_zc_to_xdp_frame(xdp); | |
214 | ||
215 | /* Store info in top of packet */ | |
216 | xdp_frame = xdp->data_hard_start; | |
217 | if (unlikely(xdp_update_frame_from_buff(xdp, xdp_frame) < 0)) | |
218 | return NULL; | |
219 | ||
c0048cff JDB |
220 | /* rxq only valid until napi_schedule ends, convert to xdp_mem_info */ |
221 | xdp_frame->mem = xdp->rxq->mem; | |
222 | ||
223 | return xdp_frame; | |
224 | } | |
225 | ||
03993094 | 226 | void xdp_return_frame(struct xdp_frame *xdpf); |
389ab7f0 | 227 | void xdp_return_frame_rx_napi(struct xdp_frame *xdpf); |
c497176c | 228 | void xdp_return_buff(struct xdp_buff *xdp); |
89653987 LB |
229 | void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq); |
230 | void xdp_return_frame_bulk(struct xdp_frame *xdpf, | |
231 | struct xdp_frame_bulk *bq); | |
5ab073ff | 232 | |
6bf071bf JDB |
233 | /* When sending xdp_frame into the network stack, then there is no |
234 | * return point callback, which is needed to release e.g. DMA-mapping | |
235 | * resources with page_pool. Thus, have explicit function to release | |
236 | * frame resources. | |
237 | */ | |
238 | void __xdp_release_frame(void *data, struct xdp_mem_info *mem); | |
239 | static inline void xdp_release_frame(struct xdp_frame *xdpf) | |
240 | { | |
241 | struct xdp_mem_info *mem = &xdpf->mem; | |
242 | ||
243 | /* Curr only page_pool needs this */ | |
244 | if (mem->type == MEM_TYPE_PAGE_POOL) | |
245 | __xdp_release_frame(xdpf->data, mem); | |
246 | } | |
247 | ||
aecd67b6 | 248 | int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq, |
b02e5a0e | 249 | struct net_device *dev, u32 queue_index, unsigned int napi_id); |
aecd67b6 JDB |
250 | void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq); |
251 | void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq); | |
c0124f32 | 252 | bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq); |
5ab073ff JDB |
253 | int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq, |
254 | enum xdp_mem_type type, void *allocator); | |
dce5bd61 | 255 | void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq); |
aecd67b6 | 256 | |
106ca27f JDB |
257 | /* Drivers not supporting XDP metadata can use this helper, which |
258 | * rejects any room expansion for metadata as a result. | |
259 | */ | |
260 | static __always_inline void | |
261 | xdp_set_data_meta_invalid(struct xdp_buff *xdp) | |
262 | { | |
263 | xdp->data_meta = xdp->data + 1; | |
264 | } | |
265 | ||
266 | static __always_inline bool | |
267 | xdp_data_meta_unsupported(const struct xdp_buff *xdp) | |
268 | { | |
269 | return unlikely(xdp->data_meta > xdp->data); | |
270 | } | |
271 | ||
05296620 JK |
272 | struct xdp_attachment_info { |
273 | struct bpf_prog *prog; | |
274 | u32 flags; | |
275 | }; | |
276 | ||
277 | struct netdev_bpf; | |
05296620 JK |
278 | void xdp_attachment_setup(struct xdp_attachment_info *info, |
279 | struct netdev_bpf *bpf); | |
280 | ||
89653987 | 281 | #define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE |
788f87ac | 282 | |
aecd67b6 | 283 | #endif /* __LINUX_NET_XDP_H__ */ |