1 /*
2  * Copyright (C) 2016-2018 Netronome Systems, Inc.
3  *
4  * This software is dual licensed under the GNU General License Version 2,
5  * June 1991 as shown in the file COPYING in the top-level directory of this
6  * source tree or the BSD 2-Clause License provided below.  You have the
7  * option to license this software under the complete terms of either license.
8  *
9  * The BSD 2-Clause License:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      1. Redistributions of source code must retain the above
16  *         copyright notice, this list of conditions and the following
17  *         disclaimer.
18  *
19  *      2. Redistributions in binary form must reproduce the above
20  *         copyright notice, this list of conditions and the following
21  *         disclaimer in the documentation and/or other materials
22  *         provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #ifndef __NFP_BPF_H__
35 #define __NFP_BPF_H__ 1
36 
37 #include <linux/bitfield.h>
38 #include <linux/bpf.h>
39 #include <linux/bpf_verifier.h>
40 #include <linux/kernel.h>
41 #include <linux/list.h>
42 #include <linux/rhashtable.h>
43 #include <linux/skbuff.h>
44 #include <linux/types.h>
45 #include <linux/wait.h>
46 
47 #include "../nfp_asm.h"
48 #include "fw.h"
49 
50 /* For relocation logic use up-most byte of branch instruction as scratch
51  * area.  Remember to clear this before sending instructions to HW!
52  */
53 #define OP_RELO_TYPE	0xff00000000000000ULL
54 
55 enum nfp_relo_type {
56 	RELO_NONE = 0,
57 	/* standard internal jumps */
58 	RELO_BR_REL,
59 	/* internal jumps to parts of the outro */
60 	RELO_BR_GO_OUT,
61 	RELO_BR_GO_ABORT,
62 	/* external jumps to fixed addresses */
63 	RELO_BR_NEXT_PKT,
64 	RELO_BR_HELPER,
65 	/* immediate relocation against load address */
66 	RELO_IMMED_REL,
67 };
68 
69 /* To make absolute relocated branches (branches other than RELO_BR_REL)
70  * distinguishable in user space dumps from normal jumps, add a large offset
71  * to them.
72  */
73 #define BR_OFF_RELO		15000
74 
75 enum static_regs {
76 	STATIC_REG_IMMA		= 20, /* Bank AB */
77 	STATIC_REG_IMM		= 21, /* Bank AB */
78 	STATIC_REG_STACK	= 22, /* Bank A */
79 	STATIC_REG_PKT_LEN	= 22, /* Bank B */
80 };
81 
82 enum pkt_vec {
83 	PKT_VEC_PKT_LEN		= 0,
84 	PKT_VEC_PKT_PTR		= 2,
85 };
86 
87 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
88 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
89 
90 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
91 #define stack_imm(np)	imm_b(np)
92 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
93 #define pptr_reg(np)	pv_ctm_ptr(np)
94 #define imm_a(np)	reg_a(STATIC_REG_IMM)
95 #define imm_b(np)	reg_b(STATIC_REG_IMM)
96 #define imma_a(np)	reg_a(STATIC_REG_IMMA)
97 #define imma_b(np)	reg_b(STATIC_REG_IMMA)
98 #define imm_both(np)	reg_both(STATIC_REG_IMM)
99 
100 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
101 #define   NFP_BPF_ABI_FLAG_MARK	1
102 
103 /**
104  * struct nfp_app_bpf - bpf app priv structure
105  * @app:		backpointer to the app
106  *
107  * @tag_allocator:	bitmap of control message tags in use
108  * @tag_alloc_next:	next tag bit to allocate
109  * @tag_alloc_last:	next tag bit to be freed
110  *
111  * @cmsg_replies:	received cmsg replies waiting to be consumed
112  * @cmsg_wq:		work queue for waiting for cmsg replies
113  *
114  * @map_list:		list of offloaded maps
115  * @maps_in_use:	number of currently offloaded maps
116  * @map_elems_in_use:	number of elements allocated to offloaded maps
117  *
118  * @maps_neutral:	hash table of offload-neutral maps (on pointer)
119  *
120  * @adjust_head:	adjust head capability
121  * @adjust_head.flags:		extra flags for adjust head
122  * @adjust_head.off_min:	minimal packet offset within buffer required
123  * @adjust_head.off_max:	maximum packet offset within buffer required
124  * @adjust_head.guaranteed_sub:	negative adjustment guaranteed possible
125  * @adjust_head.guaranteed_add:	positive adjustment guaranteed possible
126  *
127  * @maps:		map capability
128  * @maps.types:			supported map types
129  * @maps.max_maps:		max number of maps supported
130  * @maps.max_elems:		max number of entries in each map
131  * @maps.max_key_sz:		max size of map key
132  * @maps.max_val_sz:		max size of map value
133  * @maps.max_elem_sz:		max size of map entry (key + value)
134  *
135  * @helpers:		helper addressess for various calls
136  * @helpers.map_lookup:		map lookup helper address
137  * @helpers.map_update:		map update helper address
138  * @helpers.map_delete:		map delete helper address
139  *
140  * @pseudo_random:	FW initialized the pseudo-random machinery (CSRs)
141  */
142 struct nfp_app_bpf {
143 	struct nfp_app *app;
144 
145 	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
146 	u16 tag_alloc_next;
147 	u16 tag_alloc_last;
148 
149 	struct sk_buff_head cmsg_replies;
150 	struct wait_queue_head cmsg_wq;
151 
152 	struct list_head map_list;
153 	unsigned int maps_in_use;
154 	unsigned int map_elems_in_use;
155 
156 	struct rhashtable maps_neutral;
157 
158 	struct nfp_bpf_cap_adjust_head {
159 		u32 flags;
160 		int off_min;
161 		int off_max;
162 		int guaranteed_sub;
163 		int guaranteed_add;
164 	} adjust_head;
165 
166 	struct {
167 		u32 types;
168 		u32 max_maps;
169 		u32 max_elems;
170 		u32 max_key_sz;
171 		u32 max_val_sz;
172 		u32 max_elem_sz;
173 	} maps;
174 
175 	struct {
176 		u32 map_lookup;
177 		u32 map_update;
178 		u32 map_delete;
179 	} helpers;
180 
181 	bool pseudo_random;
182 };
183 
184 enum nfp_bpf_map_use {
185 	NFP_MAP_UNUSED = 0,
186 	NFP_MAP_USE_READ,
187 	NFP_MAP_USE_WRITE,
188 	NFP_MAP_USE_ATOMIC_CNT,
189 };
190 
191 /**
192  * struct nfp_bpf_map - private per-map data attached to BPF maps for offload
193  * @offmap:	pointer to the offloaded BPF map
194  * @bpf:	back pointer to bpf app private structure
195  * @tid:	table id identifying map on datapath
196  * @l:		link on the nfp_app_bpf->map_list list
197  * @use_map:	map of how the value is used (in 4B chunks)
198  */
199 struct nfp_bpf_map {
200 	struct bpf_offloaded_map *offmap;
201 	struct nfp_app_bpf *bpf;
202 	u32 tid;
203 	struct list_head l;
204 	enum nfp_bpf_map_use use_map[];
205 };
206 
207 struct nfp_bpf_neutral_map {
208 	struct rhash_head l;
209 	struct bpf_map *ptr;
210 	u32 count;
211 };
212 
213 extern const struct rhashtable_params nfp_bpf_maps_neutral_params;
214 
215 struct nfp_prog;
216 struct nfp_insn_meta;
217 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
218 
219 #define nfp_prog_first_meta(nfp_prog)					\
220 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
221 #define nfp_prog_last_meta(nfp_prog)					\
222 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
223 #define nfp_meta_next(meta)	list_next_entry(meta, l)
224 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
225 
226 /**
227  * struct nfp_bpf_reg_state - register state for calls
228  * @reg: BPF register state from latest path
229  * @var_off: for stack arg - changes stack offset on different paths
230  */
231 struct nfp_bpf_reg_state {
232 	struct bpf_reg_state reg;
233 	bool var_off;
234 };
235 
236 #define FLAG_INSN_IS_JUMP_DST	BIT(0)
237 
238 /**
239  * struct nfp_insn_meta - BPF instruction wrapper
240  * @insn: BPF instruction
241  * @ptr: pointer type for memory operations
242  * @ldst_gather_len: memcpy length gathered from load/store sequence
243  * @paired_st: the paired store insn at the head of the sequence
244  * @ptr_not_const: pointer is not always constant
245  * @pkt_cache: packet data cache information
246  * @pkt_cache.range_start: start offset for associated packet data cache
247  * @pkt_cache.range_end: end offset for associated packet data cache
248  * @pkt_cache.do_init: this read needs to initialize packet data cache
249  * @xadd_over_16bit: 16bit immediate is not guaranteed
250  * @xadd_maybe_16bit: 16bit immediate is possible
251  * @jmp_dst: destination info for jump instructions
252  * @jump_neg_op: jump instruction has inverted immediate, use ADD instead of SUB
253  * @func_id: function id for call instructions
254  * @arg1: arg1 for call instructions
255  * @arg2: arg2 for call instructions
256  * @off: index of first generated machine instruction (in nfp_prog.prog)
257  * @n: eBPF instruction number
258  * @flags: eBPF instruction extra optimization flags
259  * @skip: skip this instruction (optimized out)
260  * @double_cb: callback for second part of the instruction
261  * @l: link on nfp_prog->insns list
262  */
263 struct nfp_insn_meta {
264 	struct bpf_insn insn;
265 	union {
266 		/* pointer ops (ld/st/xadd) */
267 		struct {
268 			struct bpf_reg_state ptr;
269 			struct bpf_insn *paired_st;
270 			s16 ldst_gather_len;
271 			bool ptr_not_const;
272 			struct {
273 				s16 range_start;
274 				s16 range_end;
275 				bool do_init;
276 			} pkt_cache;
277 			bool xadd_over_16bit;
278 			bool xadd_maybe_16bit;
279 		};
280 		/* jump */
281 		struct {
282 			struct nfp_insn_meta *jmp_dst;
283 			bool jump_neg_op;
284 		};
285 		/* function calls */
286 		struct {
287 			u32 func_id;
288 			struct bpf_reg_state arg1;
289 			struct nfp_bpf_reg_state arg2;
290 		};
291 	};
292 	unsigned int off;
293 	unsigned short n;
294 	unsigned short flags;
295 	bool skip;
296 	instr_cb_t double_cb;
297 
298 	struct list_head l;
299 };
300 
301 #define BPF_SIZE_MASK	0x18
302 
303 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
304 {
305 	return BPF_CLASS(meta->insn.code);
306 }
307 
308 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
309 {
310 	return BPF_SRC(meta->insn.code);
311 }
312 
313 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
314 {
315 	return BPF_OP(meta->insn.code);
316 }
317 
318 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
319 {
320 	return BPF_MODE(meta->insn.code);
321 }
322 
323 static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
324 {
325 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
326 }
327 
328 static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
329 {
330 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
331 }
332 
333 static inline bool is_mbpf_load_pkt(const struct nfp_insn_meta *meta)
334 {
335 	return is_mbpf_load(meta) && meta->ptr.type == PTR_TO_PACKET;
336 }
337 
338 static inline bool is_mbpf_store_pkt(const struct nfp_insn_meta *meta)
339 {
340 	return is_mbpf_store(meta) && meta->ptr.type == PTR_TO_PACKET;
341 }
342 
343 static inline bool is_mbpf_classic_load(const struct nfp_insn_meta *meta)
344 {
345 	u8 code = meta->insn.code;
346 
347 	return BPF_CLASS(code) == BPF_LD &&
348 	       (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND);
349 }
350 
351 static inline bool is_mbpf_classic_store(const struct nfp_insn_meta *meta)
352 {
353 	u8 code = meta->insn.code;
354 
355 	return BPF_CLASS(code) == BPF_ST && BPF_MODE(code) == BPF_MEM;
356 }
357 
358 static inline bool is_mbpf_classic_store_pkt(const struct nfp_insn_meta *meta)
359 {
360 	return is_mbpf_classic_store(meta) && meta->ptr.type == PTR_TO_PACKET;
361 }
362 
363 static inline bool is_mbpf_xadd(const struct nfp_insn_meta *meta)
364 {
365 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_XADD);
366 }
367 
368 /**
369  * struct nfp_prog - nfp BPF program
370  * @bpf: backpointer to the bpf app priv structure
371  * @prog: machine code
372  * @prog_len: number of valid instructions in @prog array
373  * @__prog_alloc_len: alloc size of @prog array
374  * @verifier_meta: temporary storage for verifier's insn meta
375  * @type: BPF program type
376  * @last_bpf_off: address of the last instruction translated from BPF
377  * @tgt_out: jump target for normal exit
378  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
379  * @n_translated: number of successfully translated instructions (for errors)
380  * @error: error code if something went wrong
381  * @stack_depth: max stack depth from the verifier
382  * @adjust_head_location: if program has single adjust head call - the insn no.
383  * @map_records_cnt: the number of map pointers recorded for this prog
384  * @map_records: the map record pointers from bpf->maps_neutral
385  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
386  */
387 struct nfp_prog {
388 	struct nfp_app_bpf *bpf;
389 
390 	u64 *prog;
391 	unsigned int prog_len;
392 	unsigned int __prog_alloc_len;
393 
394 	struct nfp_insn_meta *verifier_meta;
395 
396 	enum bpf_prog_type type;
397 
398 	unsigned int last_bpf_off;
399 	unsigned int tgt_out;
400 	unsigned int tgt_abort;
401 
402 	unsigned int n_translated;
403 	int error;
404 
405 	unsigned int stack_depth;
406 	unsigned int adjust_head_location;
407 
408 	unsigned int map_records_cnt;
409 	struct nfp_bpf_neutral_map **map_records;
410 
411 	struct list_head insns;
412 };
413 
414 /**
415  * struct nfp_bpf_vnic - per-vNIC BPF priv structure
416  * @tc_prog:	currently loaded cls_bpf program
417  * @start_off:	address of the first instruction in the memory
418  * @tgt_done:	jump target to get the next packet
419  */
420 struct nfp_bpf_vnic {
421 	struct bpf_prog *tc_prog;
422 	unsigned int start_off;
423 	unsigned int tgt_done;
424 };
425 
426 void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
427 int nfp_bpf_jit(struct nfp_prog *prog);
428 bool nfp_bpf_supported_opcode(u8 code);
429 
430 extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
431 
432 struct netdev_bpf;
433 struct nfp_app;
434 struct nfp_net;
435 
436 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn,
437 		struct netdev_bpf *bpf);
438 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
439 			bool old_prog, struct netlink_ext_ack *extack);
440 
441 struct nfp_insn_meta *
442 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
443 		  unsigned int insn_idx, unsigned int n_insns);
444 
445 void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv);
446 
447 long long int
448 nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map);
449 void
450 nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map);
451 int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
452 				void *next_key);
453 int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
454 			      void *key, void *value, u64 flags);
455 int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key);
456 int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
457 			      void *key, void *value);
458 int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
459 			       void *key, void *next_key);
460 
461 void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb);
462 #endif
463