1 /* SPDX-License-Identifier: GPL-2.0-only */
4 * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
6 #ifndef __LINUX_NET_XDP_H__
7 #define __LINUX_NET_XDP_H__
9 #include <linux/skbuff.h> /* skb_shared_info */
10 #include <uapi/linux/netdev.h>
11 #include <linux/bitfield.h>
14 * DOC: XDP RX-queue information
16 * The XDP RX-queue info (xdp_rxq_info) is associated with the driver
17 * level RX-ring queues. It is information that is specific to how
18 * the driver have configured a given RX-ring queue.
20 * Each xdp_buff frame received in the driver carries a (pointer)
21 * reference to this xdp_rxq_info structure. This provides the XDP
22 * data-path read-access to RX-info for both kernel and bpf-side
25 * For now, direct access is only safe while running in NAPI/softirq
26 * context. Contents are read-mostly and must not be updated during
27 * driver NAPI/softirq poll.
29 * The driver usage API is a register and unregister API.
31 * The struct is not directly tied to the XDP prog. A new XDP prog
32 * can be attached as long as it doesn't change the underlying
33 * RX-ring. If the RX-ring does change significantly, the NIC driver
34 * naturally need to stop the RX-ring before purging and reallocating
35 * memory. In that process the driver MUST call unregister (which
36 * also applies for driver shutdown and unload). The register API is
37 * also mandatory during RX-ring setup.
41 MEM_TYPE_PAGE_SHARED = 0, /* Split-page refcnt based model */
42 MEM_TYPE_PAGE_ORDER0, /* Orig XDP full page model */
44 MEM_TYPE_XSK_BUFF_POOL,
48 typedef u32 xdp_features_t;
50 /* XDP flags for ndo_xdp_xmit */
51 #define XDP_XMIT_FLUSH (1U << 0) /* doorbell signal consumer */
52 #define XDP_XMIT_FLAGS_MASK XDP_XMIT_FLUSH
55 u32 type; /* enum xdp_mem_type, but known size type */
62 struct net_device *dev;
65 struct xdp_mem_info mem;
68 } ____cacheline_aligned; /* perf critical, avoid false-sharing */
71 struct net_device *dev;
75 XDP_FLAGS_HAS_FRAGS = BIT(0), /* non-linear xdp buff */
76 XDP_FLAGS_FRAGS_PF_MEMALLOC = BIT(1), /* xdp paged memory is under
85 void *data_hard_start;
86 struct xdp_rxq_info *rxq;
87 struct xdp_txq_info *txq;
88 u32 frame_sz; /* frame size to deduce data_hard_end/reserved tailroom*/
89 u32 flags; /* supported values defined in xdp_buff_flags */
92 static __always_inline bool xdp_buff_has_frags(struct xdp_buff *xdp)
94 return !!(xdp->flags & XDP_FLAGS_HAS_FRAGS);
97 static __always_inline void xdp_buff_set_frags_flag(struct xdp_buff *xdp)
99 xdp->flags |= XDP_FLAGS_HAS_FRAGS;
102 static __always_inline void xdp_buff_clear_frags_flag(struct xdp_buff *xdp)
104 xdp->flags &= ~XDP_FLAGS_HAS_FRAGS;
107 static __always_inline bool xdp_buff_is_frag_pfmemalloc(struct xdp_buff *xdp)
109 return !!(xdp->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
112 static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
114 xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
117 static __always_inline void
118 xdp_init_buff(struct xdp_buff *xdp, u32 frame_sz, struct xdp_rxq_info *rxq)
120 xdp->frame_sz = frame_sz;
125 static __always_inline void
126 xdp_prepare_buff(struct xdp_buff *xdp, unsigned char *hard_start,
127 int headroom, int data_len, const bool meta_valid)
129 unsigned char *data = hard_start + headroom;
131 xdp->data_hard_start = hard_start;
133 xdp->data_end = data + data_len;
134 xdp->data_meta = meta_valid ? data : data + 1;
137 /* Reserve memory area at end-of data area.
139 * This macro reserves tailroom in the XDP buffer by limiting the
140 * XDP/BPF data access to data_hard_end. Notice same area (and size)
141 * is used for XDP_PASS, when constructing the SKB via build_skb().
143 #define xdp_data_hard_end(xdp) \
144 ((xdp)->data_hard_start + (xdp)->frame_sz - \
145 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
147 static inline struct skb_shared_info *
148 xdp_get_shared_info_from_buff(struct xdp_buff *xdp)
150 return (struct skb_shared_info *)xdp_data_hard_end(xdp);
153 static __always_inline unsigned int xdp_get_buff_len(struct xdp_buff *xdp)
155 unsigned int len = xdp->data_end - xdp->data;
156 struct skb_shared_info *sinfo;
158 if (likely(!xdp_buff_has_frags(xdp)))
161 sinfo = xdp_get_shared_info_from_buff(xdp);
162 len += sinfo->xdp_frags_size;
171 u32 metasize; /* uses lower 8-bits */
172 /* Lifetime of xdp_rxq_info is limited to NAPI/enqueue time,
173 * while mem info is valid on remote CPU.
175 struct xdp_mem_info mem;
176 struct net_device *dev_rx; /* used by cpumap */
178 u32 flags; /* supported values defined in xdp_buff_flags */
181 static __always_inline bool xdp_frame_has_frags(struct xdp_frame *frame)
183 return !!(frame->flags & XDP_FLAGS_HAS_FRAGS);
186 static __always_inline bool xdp_frame_is_frag_pfmemalloc(struct xdp_frame *frame)
188 return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
191 #define XDP_BULK_QUEUE_SIZE 16
192 struct xdp_frame_bulk {
195 void *q[XDP_BULK_QUEUE_SIZE];
198 static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq)
200 /* bq->count will be zero'ed when bq->xa gets updated */
204 static inline struct skb_shared_info *
205 xdp_get_shared_info_from_frame(struct xdp_frame *frame)
207 void *data_hard_start = frame->data - frame->headroom - sizeof(*frame);
209 return (struct skb_shared_info *)(data_hard_start + frame->frame_sz -
210 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
213 struct xdp_cpumap_stats {
214 unsigned int redirect;
219 /* Clear kernel pointers in xdp_frame */
220 static inline void xdp_scrub_frame(struct xdp_frame *frame)
223 frame->dev_rx = NULL;
227 xdp_update_skb_shared_info(struct sk_buff *skb, u8 nr_frags,
228 unsigned int size, unsigned int truesize,
231 skb_shinfo(skb)->nr_frags = nr_frags;
234 skb->data_len += size;
235 skb->truesize += truesize;
236 skb->pfmemalloc |= pfmemalloc;
239 /* Avoids inlining WARN macro in fast-path */
240 void xdp_warn(const char *msg, const char *func, const int line);
241 #define XDP_WARN(msg) xdp_warn(msg, __func__, __LINE__)
243 struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp);
244 struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf,
246 struct net_device *dev);
247 struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf,
248 struct net_device *dev);
249 int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp);
250 struct xdp_frame *xdpf_clone(struct xdp_frame *xdpf);
253 void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp)
255 xdp->data_hard_start = frame->data - frame->headroom - sizeof(*frame);
256 xdp->data = frame->data;
257 xdp->data_end = frame->data + frame->len;
258 xdp->data_meta = frame->data - frame->metasize;
259 xdp->frame_sz = frame->frame_sz;
260 xdp->flags = frame->flags;
264 int xdp_update_frame_from_buff(struct xdp_buff *xdp,
265 struct xdp_frame *xdp_frame)
267 int metasize, headroom;
269 /* Assure headroom is available for storing info */
270 headroom = xdp->data - xdp->data_hard_start;
271 metasize = xdp->data - xdp->data_meta;
272 metasize = metasize > 0 ? metasize : 0;
273 if (unlikely((headroom - metasize) < sizeof(*xdp_frame)))
276 /* Catch if driver didn't reserve tailroom for skb_shared_info */
277 if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) {
278 XDP_WARN("Driver BUG: missing reserved tailroom");
282 xdp_frame->data = xdp->data;
283 xdp_frame->len = xdp->data_end - xdp->data;
284 xdp_frame->headroom = headroom - sizeof(*xdp_frame);
285 xdp_frame->metasize = metasize;
286 xdp_frame->frame_sz = xdp->frame_sz;
287 xdp_frame->flags = xdp->flags;
292 /* Convert xdp_buff to xdp_frame */
294 struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp)
296 struct xdp_frame *xdp_frame;
298 if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL)
299 return xdp_convert_zc_to_xdp_frame(xdp);
301 /* Store info in top of packet */
302 xdp_frame = xdp->data_hard_start;
303 if (unlikely(xdp_update_frame_from_buff(xdp, xdp_frame) < 0))
306 /* rxq only valid until napi_schedule ends, convert to xdp_mem_info */
307 xdp_frame->mem = xdp->rxq->mem;
312 void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
313 struct xdp_buff *xdp);
314 void xdp_return_frame(struct xdp_frame *xdpf);
315 void xdp_return_frame_rx_napi(struct xdp_frame *xdpf);
316 void xdp_return_buff(struct xdp_buff *xdp);
317 void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq);
318 void xdp_return_frame_bulk(struct xdp_frame *xdpf,
319 struct xdp_frame_bulk *bq);
321 static __always_inline unsigned int xdp_get_frame_len(struct xdp_frame *xdpf)
323 struct skb_shared_info *sinfo;
324 unsigned int len = xdpf->len;
326 if (likely(!xdp_frame_has_frags(xdpf)))
329 sinfo = xdp_get_shared_info_from_frame(xdpf);
330 len += sinfo->xdp_frags_size;
335 int __xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
336 struct net_device *dev, u32 queue_index,
337 unsigned int napi_id, u32 frag_size);
339 xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
340 struct net_device *dev, u32 queue_index,
341 unsigned int napi_id)
343 return __xdp_rxq_info_reg(xdp_rxq, dev, queue_index, napi_id, 0);
346 void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq);
347 void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq);
348 bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq);
349 int xdp_rxq_info_reg_mem_model(struct xdp_rxq_info *xdp_rxq,
350 enum xdp_mem_type type, void *allocator);
351 void xdp_rxq_info_unreg_mem_model(struct xdp_rxq_info *xdp_rxq);
352 int xdp_reg_mem_model(struct xdp_mem_info *mem,
353 enum xdp_mem_type type, void *allocator);
354 void xdp_unreg_mem_model(struct xdp_mem_info *mem);
356 /* Drivers not supporting XDP metadata can use this helper, which
357 * rejects any room expansion for metadata as a result.
359 static __always_inline void
360 xdp_set_data_meta_invalid(struct xdp_buff *xdp)
362 xdp->data_meta = xdp->data + 1;
365 static __always_inline bool
366 xdp_data_meta_unsupported(const struct xdp_buff *xdp)
368 return unlikely(xdp->data_meta > xdp->data);
371 static inline bool xdp_metalen_invalid(unsigned long metalen)
373 return (metalen & (sizeof(__u32) - 1)) || (metalen > 32);
376 struct xdp_attachment_info {
377 struct bpf_prog *prog;
382 void xdp_attachment_setup(struct xdp_attachment_info *info,
383 struct netdev_bpf *bpf);
385 #define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE
387 #define XDP_METADATA_KFUNC_xxx \
388 XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_TIMESTAMP, \
389 bpf_xdp_metadata_rx_timestamp) \
390 XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \
391 bpf_xdp_metadata_rx_hash) \
394 #define XDP_METADATA_KFUNC(name, _) name,
395 XDP_METADATA_KFUNC_xxx
396 #undef XDP_METADATA_KFUNC
397 MAX_XDP_METADATA_KFUNC,
400 enum xdp_rss_hash_type {
401 /* First part: Individual bits for L3/L4 types */
402 XDP_RSS_L3_IPV4 = BIT(0),
403 XDP_RSS_L3_IPV6 = BIT(1),
405 /* The fixed (L3) IPv4 and IPv6 headers can both be followed by
406 * variable/dynamic headers, IPv4 called Options and IPv6 called
407 * Extension Headers. HW RSS type can contain this info.
409 XDP_RSS_L3_DYNHDR = BIT(2),
411 /* When RSS hash covers L4 then drivers MUST set XDP_RSS_L4 bit in
412 * addition to the protocol specific bit. This ease interaction with
413 * SKBs and avoids reserving a fixed mask for future L4 protocol bits.
415 XDP_RSS_L4 = BIT(3), /* L4 based hash, proto can be unknown */
416 XDP_RSS_L4_TCP = BIT(4),
417 XDP_RSS_L4_UDP = BIT(5),
418 XDP_RSS_L4_SCTP = BIT(6),
419 XDP_RSS_L4_IPSEC = BIT(7), /* L4 based hash include IPSEC SPI */
421 /* Second part: RSS hash type combinations used for driver HW mapping */
422 XDP_RSS_TYPE_NONE = 0,
423 XDP_RSS_TYPE_L2 = XDP_RSS_TYPE_NONE,
425 XDP_RSS_TYPE_L3_IPV4 = XDP_RSS_L3_IPV4,
426 XDP_RSS_TYPE_L3_IPV6 = XDP_RSS_L3_IPV6,
427 XDP_RSS_TYPE_L3_IPV4_OPT = XDP_RSS_L3_IPV4 | XDP_RSS_L3_DYNHDR,
428 XDP_RSS_TYPE_L3_IPV6_EX = XDP_RSS_L3_IPV6 | XDP_RSS_L3_DYNHDR,
430 XDP_RSS_TYPE_L4_ANY = XDP_RSS_L4,
431 XDP_RSS_TYPE_L4_IPV4_TCP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_TCP,
432 XDP_RSS_TYPE_L4_IPV4_UDP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_UDP,
433 XDP_RSS_TYPE_L4_IPV4_SCTP = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_SCTP,
434 XDP_RSS_TYPE_L4_IPV4_IPSEC = XDP_RSS_L3_IPV4 | XDP_RSS_L4 | XDP_RSS_L4_IPSEC,
436 XDP_RSS_TYPE_L4_IPV6_TCP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_TCP,
437 XDP_RSS_TYPE_L4_IPV6_UDP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_UDP,
438 XDP_RSS_TYPE_L4_IPV6_SCTP = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_SCTP,
439 XDP_RSS_TYPE_L4_IPV6_IPSEC = XDP_RSS_L3_IPV6 | XDP_RSS_L4 | XDP_RSS_L4_IPSEC,
441 XDP_RSS_TYPE_L4_IPV6_TCP_EX = XDP_RSS_TYPE_L4_IPV6_TCP | XDP_RSS_L3_DYNHDR,
442 XDP_RSS_TYPE_L4_IPV6_UDP_EX = XDP_RSS_TYPE_L4_IPV6_UDP | XDP_RSS_L3_DYNHDR,
443 XDP_RSS_TYPE_L4_IPV6_SCTP_EX = XDP_RSS_TYPE_L4_IPV6_SCTP | XDP_RSS_L3_DYNHDR,
447 u32 bpf_xdp_metadata_kfunc_id(int id);
448 bool bpf_dev_bound_kfunc_id(u32 btf_id);
449 void xdp_set_features_flag(struct net_device *dev, xdp_features_t val);
450 void xdp_features_set_redirect_target(struct net_device *dev, bool support_sg);
451 void xdp_features_clear_redirect_target(struct net_device *dev);
453 static inline u32 bpf_xdp_metadata_kfunc_id(int id) { return 0; }
454 static inline bool bpf_dev_bound_kfunc_id(u32 btf_id) { return false; }
457 xdp_set_features_flag(struct net_device *dev, xdp_features_t val)
462 xdp_features_set_redirect_target(struct net_device *dev, bool support_sg)
467 xdp_features_clear_redirect_target(struct net_device *dev)
472 static inline void xdp_clear_features_flag(struct net_device *dev)
474 xdp_set_features_flag(dev, 0);
477 #endif /* __LINUX_NET_XDP_H__ */