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 	PKT_VEC_QSEL_SET	= 4,
86 	PKT_VEC_QSEL_VAL	= 6,
87 };
88 
89 #define PKT_VEL_QSEL_SET_BIT	4
90 
91 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
92 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
93 #define pv_qsel_set(np)	reg_lm(1, PKT_VEC_QSEL_SET)
94 #define pv_qsel_val(np)	reg_lm(1, PKT_VEC_QSEL_VAL)
95 
96 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
97 #define stack_imm(np)	imm_b(np)
98 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
99 #define pptr_reg(np)	pv_ctm_ptr(np)
100 #define imm_a(np)	reg_a(STATIC_REG_IMM)
101 #define imm_b(np)	reg_b(STATIC_REG_IMM)
102 #define imma_a(np)	reg_a(STATIC_REG_IMMA)
103 #define imma_b(np)	reg_b(STATIC_REG_IMMA)
104 #define imm_both(np)	reg_both(STATIC_REG_IMM)
105 
106 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
107 #define   NFP_BPF_ABI_FLAG_MARK	1
108 
109 /**
110  * struct nfp_app_bpf - bpf app priv structure
111  * @app:		backpointer to the app
112  *
113  * @tag_allocator:	bitmap of control message tags in use
114  * @tag_alloc_next:	next tag bit to allocate
115  * @tag_alloc_last:	next tag bit to be freed
116  *
117  * @cmsg_replies:	received cmsg replies waiting to be consumed
118  * @cmsg_wq:		work queue for waiting for cmsg replies
119  *
120  * @map_list:		list of offloaded maps
121  * @maps_in_use:	number of currently offloaded maps
122  * @map_elems_in_use:	number of elements allocated to offloaded maps
123  *
124  * @maps_neutral:	hash table of offload-neutral maps (on pointer)
125  *
126  * @adjust_head:	adjust head capability
127  * @adjust_head.flags:		extra flags for adjust head
128  * @adjust_head.off_min:	minimal packet offset within buffer required
129  * @adjust_head.off_max:	maximum packet offset within buffer required
130  * @adjust_head.guaranteed_sub:	negative adjustment guaranteed possible
131  * @adjust_head.guaranteed_add:	positive adjustment guaranteed possible
132  *
133  * @maps:		map capability
134  * @maps.types:			supported map types
135  * @maps.max_maps:		max number of maps supported
136  * @maps.max_elems:		max number of entries in each map
137  * @maps.max_key_sz:		max size of map key
138  * @maps.max_val_sz:		max size of map value
139  * @maps.max_elem_sz:		max size of map entry (key + value)
140  *
141  * @helpers:		helper addressess for various calls
142  * @helpers.map_lookup:		map lookup helper address
143  * @helpers.map_update:		map update helper address
144  * @helpers.map_delete:		map delete helper address
145  * @helpers.perf_event_output:	output perf event to a ring buffer
146  *
147  * @pseudo_random:	FW initialized the pseudo-random machinery (CSRs)
148  * @queue_select:	BPF can set the RX queue ID in packet vector
149  */
150 struct nfp_app_bpf {
151 	struct nfp_app *app;
152 
153 	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
154 	u16 tag_alloc_next;
155 	u16 tag_alloc_last;
156 
157 	struct sk_buff_head cmsg_replies;
158 	struct wait_queue_head cmsg_wq;
159 
160 	struct list_head map_list;
161 	unsigned int maps_in_use;
162 	unsigned int map_elems_in_use;
163 
164 	struct rhashtable maps_neutral;
165 
166 	struct nfp_bpf_cap_adjust_head {
167 		u32 flags;
168 		int off_min;
169 		int off_max;
170 		int guaranteed_sub;
171 		int guaranteed_add;
172 	} adjust_head;
173 
174 	struct {
175 		u32 types;
176 		u32 max_maps;
177 		u32 max_elems;
178 		u32 max_key_sz;
179 		u32 max_val_sz;
180 		u32 max_elem_sz;
181 	} maps;
182 
183 	struct {
184 		u32 map_lookup;
185 		u32 map_update;
186 		u32 map_delete;
187 		u32 perf_event_output;
188 	} helpers;
189 
190 	bool pseudo_random;
191 	bool queue_select;
192 };
193 
194 enum nfp_bpf_map_use {
195 	NFP_MAP_UNUSED = 0,
196 	NFP_MAP_USE_READ,
197 	NFP_MAP_USE_WRITE,
198 	NFP_MAP_USE_ATOMIC_CNT,
199 };
200 
201 /**
202  * struct nfp_bpf_map - private per-map data attached to BPF maps for offload
203  * @offmap:	pointer to the offloaded BPF map
204  * @bpf:	back pointer to bpf app private structure
205  * @tid:	table id identifying map on datapath
206  * @l:		link on the nfp_app_bpf->map_list list
207  * @use_map:	map of how the value is used (in 4B chunks)
208  */
209 struct nfp_bpf_map {
210 	struct bpf_offloaded_map *offmap;
211 	struct nfp_app_bpf *bpf;
212 	u32 tid;
213 	struct list_head l;
214 	enum nfp_bpf_map_use use_map[];
215 };
216 
217 struct nfp_bpf_neutral_map {
218 	struct rhash_head l;
219 	struct bpf_map *ptr;
220 	u32 count;
221 };
222 
223 extern const struct rhashtable_params nfp_bpf_maps_neutral_params;
224 
225 struct nfp_prog;
226 struct nfp_insn_meta;
227 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
228 
229 #define nfp_prog_first_meta(nfp_prog)					\
230 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
231 #define nfp_prog_last_meta(nfp_prog)					\
232 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
233 #define nfp_meta_next(meta)	list_next_entry(meta, l)
234 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
235 
236 /**
237  * struct nfp_bpf_reg_state - register state for calls
238  * @reg: BPF register state from latest path
239  * @var_off: for stack arg - changes stack offset on different paths
240  */
241 struct nfp_bpf_reg_state {
242 	struct bpf_reg_state reg;
243 	bool var_off;
244 };
245 
246 #define FLAG_INSN_IS_JUMP_DST	BIT(0)
247 
248 /**
249  * struct nfp_insn_meta - BPF instruction wrapper
250  * @insn: BPF instruction
251  * @ptr: pointer type for memory operations
252  * @ldst_gather_len: memcpy length gathered from load/store sequence
253  * @paired_st: the paired store insn at the head of the sequence
254  * @ptr_not_const: pointer is not always constant
255  * @pkt_cache: packet data cache information
256  * @pkt_cache.range_start: start offset for associated packet data cache
257  * @pkt_cache.range_end: end offset for associated packet data cache
258  * @pkt_cache.do_init: this read needs to initialize packet data cache
259  * @xadd_over_16bit: 16bit immediate is not guaranteed
260  * @xadd_maybe_16bit: 16bit immediate is possible
261  * @jmp_dst: destination info for jump instructions
262  * @jump_neg_op: jump instruction has inverted immediate, use ADD instead of SUB
263  * @func_id: function id for call instructions
264  * @arg1: arg1 for call instructions
265  * @arg2: arg2 for call instructions
266  * @umin: copy of core verifier umin_value.
267  * @umax: copy of core verifier umax_value.
268  * @off: index of first generated machine instruction (in nfp_prog.prog)
269  * @n: eBPF instruction number
270  * @flags: eBPF instruction extra optimization flags
271  * @skip: skip this instruction (optimized out)
272  * @double_cb: callback for second part of the instruction
273  * @l: link on nfp_prog->insns list
274  */
275 struct nfp_insn_meta {
276 	struct bpf_insn insn;
277 	union {
278 		/* pointer ops (ld/st/xadd) */
279 		struct {
280 			struct bpf_reg_state ptr;
281 			struct bpf_insn *paired_st;
282 			s16 ldst_gather_len;
283 			bool ptr_not_const;
284 			struct {
285 				s16 range_start;
286 				s16 range_end;
287 				bool do_init;
288 			} pkt_cache;
289 			bool xadd_over_16bit;
290 			bool xadd_maybe_16bit;
291 		};
292 		/* jump */
293 		struct {
294 			struct nfp_insn_meta *jmp_dst;
295 			bool jump_neg_op;
296 		};
297 		/* function calls */
298 		struct {
299 			u32 func_id;
300 			struct bpf_reg_state arg1;
301 			struct nfp_bpf_reg_state arg2;
302 		};
303 		/* We are interested in range info for some operands,
304 		 * for example, the shift amount.
305 		 */
306 		struct {
307 			u64 umin;
308 			u64 umax;
309 		};
310 	};
311 	unsigned int off;
312 	unsigned short n;
313 	unsigned short flags;
314 	bool skip;
315 	instr_cb_t double_cb;
316 
317 	struct list_head l;
318 };
319 
320 #define BPF_SIZE_MASK	0x18
321 
322 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
323 {
324 	return BPF_CLASS(meta->insn.code);
325 }
326 
327 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
328 {
329 	return BPF_SRC(meta->insn.code);
330 }
331 
332 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
333 {
334 	return BPF_OP(meta->insn.code);
335 }
336 
337 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
338 {
339 	return BPF_MODE(meta->insn.code);
340 }
341 
342 static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
343 {
344 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
345 }
346 
347 static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
348 {
349 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
350 }
351 
352 static inline bool is_mbpf_load_pkt(const struct nfp_insn_meta *meta)
353 {
354 	return is_mbpf_load(meta) && meta->ptr.type == PTR_TO_PACKET;
355 }
356 
357 static inline bool is_mbpf_store_pkt(const struct nfp_insn_meta *meta)
358 {
359 	return is_mbpf_store(meta) && meta->ptr.type == PTR_TO_PACKET;
360 }
361 
362 static inline bool is_mbpf_classic_load(const struct nfp_insn_meta *meta)
363 {
364 	u8 code = meta->insn.code;
365 
366 	return BPF_CLASS(code) == BPF_LD &&
367 	       (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND);
368 }
369 
370 static inline bool is_mbpf_classic_store(const struct nfp_insn_meta *meta)
371 {
372 	u8 code = meta->insn.code;
373 
374 	return BPF_CLASS(code) == BPF_ST && BPF_MODE(code) == BPF_MEM;
375 }
376 
377 static inline bool is_mbpf_classic_store_pkt(const struct nfp_insn_meta *meta)
378 {
379 	return is_mbpf_classic_store(meta) && meta->ptr.type == PTR_TO_PACKET;
380 }
381 
382 static inline bool is_mbpf_xadd(const struct nfp_insn_meta *meta)
383 {
384 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_XADD);
385 }
386 
387 static inline bool is_mbpf_indir_shift(const struct nfp_insn_meta *meta)
388 {
389 	u8 code = meta->insn.code;
390 	bool is_alu, is_shift;
391 	u8 opclass, opcode;
392 
393 	opclass = BPF_CLASS(code);
394 	is_alu = opclass == BPF_ALU64 || opclass == BPF_ALU;
395 	if (!is_alu)
396 		return false;
397 
398 	opcode = BPF_OP(code);
399 	is_shift = opcode == BPF_LSH || opcode == BPF_RSH || opcode == BPF_ARSH;
400 	if (!is_shift)
401 		return false;
402 
403 	return BPF_SRC(code) == BPF_X;
404 }
405 
406 /**
407  * struct nfp_prog - nfp BPF program
408  * @bpf: backpointer to the bpf app priv structure
409  * @prog: machine code
410  * @prog_len: number of valid instructions in @prog array
411  * @__prog_alloc_len: alloc size of @prog array
412  * @verifier_meta: temporary storage for verifier's insn meta
413  * @type: BPF program type
414  * @last_bpf_off: address of the last instruction translated from BPF
415  * @tgt_out: jump target for normal exit
416  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
417  * @n_translated: number of successfully translated instructions (for errors)
418  * @error: error code if something went wrong
419  * @stack_depth: max stack depth from the verifier
420  * @adjust_head_location: if program has single adjust head call - the insn no.
421  * @map_records_cnt: the number of map pointers recorded for this prog
422  * @map_records: the map record pointers from bpf->maps_neutral
423  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
424  */
425 struct nfp_prog {
426 	struct nfp_app_bpf *bpf;
427 
428 	u64 *prog;
429 	unsigned int prog_len;
430 	unsigned int __prog_alloc_len;
431 
432 	struct nfp_insn_meta *verifier_meta;
433 
434 	enum bpf_prog_type type;
435 
436 	unsigned int last_bpf_off;
437 	unsigned int tgt_out;
438 	unsigned int tgt_abort;
439 
440 	unsigned int n_translated;
441 	int error;
442 
443 	unsigned int stack_depth;
444 	unsigned int adjust_head_location;
445 
446 	unsigned int map_records_cnt;
447 	struct nfp_bpf_neutral_map **map_records;
448 
449 	struct list_head insns;
450 };
451 
452 /**
453  * struct nfp_bpf_vnic - per-vNIC BPF priv structure
454  * @tc_prog:	currently loaded cls_bpf program
455  * @start_off:	address of the first instruction in the memory
456  * @tgt_done:	jump target to get the next packet
457  */
458 struct nfp_bpf_vnic {
459 	struct bpf_prog *tc_prog;
460 	unsigned int start_off;
461 	unsigned int tgt_done;
462 };
463 
464 void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
465 int nfp_bpf_jit(struct nfp_prog *prog);
466 bool nfp_bpf_supported_opcode(u8 code);
467 
468 extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
469 
470 struct netdev_bpf;
471 struct nfp_app;
472 struct nfp_net;
473 
474 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn,
475 		struct netdev_bpf *bpf);
476 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
477 			bool old_prog, struct netlink_ext_ack *extack);
478 
479 struct nfp_insn_meta *
480 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
481 		  unsigned int insn_idx, unsigned int n_insns);
482 
483 void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv);
484 
485 long long int
486 nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map);
487 void
488 nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map);
489 int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
490 				void *next_key);
491 int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
492 			      void *key, void *value, u64 flags);
493 int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key);
494 int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
495 			      void *key, void *value);
496 int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
497 			       void *key, void *next_key);
498 
499 int nfp_bpf_event_output(struct nfp_app_bpf *bpf, struct sk_buff *skb);
500 
501 void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb);
502 #endif
503