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 #define cmsg_warn(bpf, msg...)	nn_dp_warn(&(bpf)->app->ctrl->dp, msg)
51 
52 /* For relocation logic use up-most byte of branch instruction as scratch
53  * area.  Remember to clear this before sending instructions to HW!
54  */
55 #define OP_RELO_TYPE	0xff00000000000000ULL
56 
57 enum nfp_relo_type {
58 	RELO_NONE = 0,
59 	/* standard internal jumps */
60 	RELO_BR_REL,
61 	/* internal jumps to parts of the outro */
62 	RELO_BR_GO_OUT,
63 	RELO_BR_GO_ABORT,
64 	RELO_BR_GO_CALL_PUSH_REGS,
65 	RELO_BR_GO_CALL_POP_REGS,
66 	/* external jumps to fixed addresses */
67 	RELO_BR_NEXT_PKT,
68 	RELO_BR_HELPER,
69 	/* immediate relocation against load address */
70 	RELO_IMMED_REL,
71 };
72 
73 /* To make absolute relocated branches (branches other than RELO_BR_REL)
74  * distinguishable in user space dumps from normal jumps, add a large offset
75  * to them.
76  */
77 #define BR_OFF_RELO		15000
78 
79 enum static_regs {
80 	STATIC_REG_IMMA		= 20, /* Bank AB */
81 	STATIC_REG_IMM		= 21, /* Bank AB */
82 	STATIC_REG_STACK	= 22, /* Bank A */
83 	STATIC_REG_PKT_LEN	= 22, /* Bank B */
84 };
85 
86 enum pkt_vec {
87 	PKT_VEC_PKT_LEN		= 0,
88 	PKT_VEC_PKT_PTR		= 2,
89 	PKT_VEC_QSEL_SET	= 4,
90 	PKT_VEC_QSEL_VAL	= 6,
91 };
92 
93 #define PKT_VEL_QSEL_SET_BIT	4
94 
95 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
96 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
97 #define pv_qsel_set(np)	reg_lm(1, PKT_VEC_QSEL_SET)
98 #define pv_qsel_val(np)	reg_lm(1, PKT_VEC_QSEL_VAL)
99 
100 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
101 #define stack_imm(np)	imm_b(np)
102 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
103 #define pptr_reg(np)	pv_ctm_ptr(np)
104 #define imm_a(np)	reg_a(STATIC_REG_IMM)
105 #define imm_b(np)	reg_b(STATIC_REG_IMM)
106 #define imma_a(np)	reg_a(STATIC_REG_IMMA)
107 #define imma_b(np)	reg_b(STATIC_REG_IMMA)
108 #define imm_both(np)	reg_both(STATIC_REG_IMM)
109 #define ret_reg(np)	imm_a(np)
110 
111 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
112 #define   NFP_BPF_ABI_FLAG_MARK	1
113 
114 /**
115  * struct nfp_app_bpf - bpf app priv structure
116  * @app:		backpointer to the app
117  *
118  * @bpf_dev:		BPF offload device handle
119  *
120  * @tag_allocator:	bitmap of control message tags in use
121  * @tag_alloc_next:	next tag bit to allocate
122  * @tag_alloc_last:	next tag bit to be freed
123  *
124  * @cmsg_replies:	received cmsg replies waiting to be consumed
125  * @cmsg_wq:		work queue for waiting for cmsg replies
126  *
127  * @cmsg_key_sz:	size of key in cmsg element array
128  * @cmsg_val_sz:	size of value in cmsg element array
129  *
130  * @map_list:		list of offloaded maps
131  * @maps_in_use:	number of currently offloaded maps
132  * @map_elems_in_use:	number of elements allocated to offloaded maps
133  *
134  * @maps_neutral:	hash table of offload-neutral maps (on pointer)
135  *
136  * @abi_version:	global BPF ABI version
137  *
138  * @adjust_head:	adjust head capability
139  * @adjust_head.flags:		extra flags for adjust head
140  * @adjust_head.off_min:	minimal packet offset within buffer required
141  * @adjust_head.off_max:	maximum packet offset within buffer required
142  * @adjust_head.guaranteed_sub:	negative adjustment guaranteed possible
143  * @adjust_head.guaranteed_add:	positive adjustment guaranteed possible
144  *
145  * @maps:		map capability
146  * @maps.types:			supported map types
147  * @maps.max_maps:		max number of maps supported
148  * @maps.max_elems:		max number of entries in each map
149  * @maps.max_key_sz:		max size of map key
150  * @maps.max_val_sz:		max size of map value
151  * @maps.max_elem_sz:		max size of map entry (key + value)
152  *
153  * @helpers:		helper addressess for various calls
154  * @helpers.map_lookup:		map lookup helper address
155  * @helpers.map_update:		map update helper address
156  * @helpers.map_delete:		map delete helper address
157  * @helpers.perf_event_output:	output perf event to a ring buffer
158  *
159  * @pseudo_random:	FW initialized the pseudo-random machinery (CSRs)
160  * @queue_select:	BPF can set the RX queue ID in packet vector
161  * @adjust_tail:	BPF can simply trunc packet size for adjust tail
162  */
163 struct nfp_app_bpf {
164 	struct nfp_app *app;
165 
166 	struct bpf_offload_dev *bpf_dev;
167 
168 	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
169 	u16 tag_alloc_next;
170 	u16 tag_alloc_last;
171 
172 	struct sk_buff_head cmsg_replies;
173 	struct wait_queue_head cmsg_wq;
174 
175 	unsigned int cmsg_key_sz;
176 	unsigned int cmsg_val_sz;
177 
178 	struct list_head map_list;
179 	unsigned int maps_in_use;
180 	unsigned int map_elems_in_use;
181 
182 	struct rhashtable maps_neutral;
183 
184 	u32 abi_version;
185 
186 	struct nfp_bpf_cap_adjust_head {
187 		u32 flags;
188 		int off_min;
189 		int off_max;
190 		int guaranteed_sub;
191 		int guaranteed_add;
192 	} adjust_head;
193 
194 	struct {
195 		u32 types;
196 		u32 max_maps;
197 		u32 max_elems;
198 		u32 max_key_sz;
199 		u32 max_val_sz;
200 		u32 max_elem_sz;
201 	} maps;
202 
203 	struct {
204 		u32 map_lookup;
205 		u32 map_update;
206 		u32 map_delete;
207 		u32 perf_event_output;
208 	} helpers;
209 
210 	bool pseudo_random;
211 	bool queue_select;
212 	bool adjust_tail;
213 };
214 
215 enum nfp_bpf_map_use {
216 	NFP_MAP_UNUSED = 0,
217 	NFP_MAP_USE_READ,
218 	NFP_MAP_USE_WRITE,
219 	NFP_MAP_USE_ATOMIC_CNT,
220 };
221 
222 /**
223  * struct nfp_bpf_map - private per-map data attached to BPF maps for offload
224  * @offmap:	pointer to the offloaded BPF map
225  * @bpf:	back pointer to bpf app private structure
226  * @tid:	table id identifying map on datapath
227  * @l:		link on the nfp_app_bpf->map_list list
228  * @use_map:	map of how the value is used (in 4B chunks)
229  */
230 struct nfp_bpf_map {
231 	struct bpf_offloaded_map *offmap;
232 	struct nfp_app_bpf *bpf;
233 	u32 tid;
234 	struct list_head l;
235 	enum nfp_bpf_map_use use_map[];
236 };
237 
238 struct nfp_bpf_neutral_map {
239 	struct rhash_head l;
240 	struct bpf_map *ptr;
241 	u32 map_id;
242 	u32 count;
243 };
244 
245 extern const struct rhashtable_params nfp_bpf_maps_neutral_params;
246 
247 struct nfp_prog;
248 struct nfp_insn_meta;
249 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
250 
251 #define nfp_prog_first_meta(nfp_prog)					\
252 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
253 #define nfp_prog_last_meta(nfp_prog)					\
254 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
255 #define nfp_meta_next(meta)	list_next_entry(meta, l)
256 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
257 
258 /**
259  * struct nfp_bpf_reg_state - register state for calls
260  * @reg: BPF register state from latest path
261  * @var_off: for stack arg - changes stack offset on different paths
262  */
263 struct nfp_bpf_reg_state {
264 	struct bpf_reg_state reg;
265 	bool var_off;
266 };
267 
268 #define FLAG_INSN_IS_JUMP_DST			BIT(0)
269 #define FLAG_INSN_IS_SUBPROG_START		BIT(1)
270 
271 /**
272  * struct nfp_insn_meta - BPF instruction wrapper
273  * @insn: BPF instruction
274  * @ptr: pointer type for memory operations
275  * @ldst_gather_len: memcpy length gathered from load/store sequence
276  * @paired_st: the paired store insn at the head of the sequence
277  * @ptr_not_const: pointer is not always constant
278  * @pkt_cache: packet data cache information
279  * @pkt_cache.range_start: start offset for associated packet data cache
280  * @pkt_cache.range_end: end offset for associated packet data cache
281  * @pkt_cache.do_init: this read needs to initialize packet data cache
282  * @xadd_over_16bit: 16bit immediate is not guaranteed
283  * @xadd_maybe_16bit: 16bit immediate is possible
284  * @jmp_dst: destination info for jump instructions
285  * @jump_neg_op: jump instruction has inverted immediate, use ADD instead of SUB
286  * @num_insns_after_br: number of insns following a branch jump, used for fixup
287  * @func_id: function id for call instructions
288  * @arg1: arg1 for call instructions
289  * @arg2: arg2 for call instructions
290  * @umin_src: copy of core verifier umin_value for src opearnd.
291  * @umax_src: copy of core verifier umax_value for src operand.
292  * @umin_dst: copy of core verifier umin_value for dst opearnd.
293  * @umax_dst: copy of core verifier umax_value for dst operand.
294  * @off: index of first generated machine instruction (in nfp_prog.prog)
295  * @n: eBPF instruction number
296  * @flags: eBPF instruction extra optimization flags
297  * @subprog_idx: index of subprogram to which the instruction belongs
298  * @skip: skip this instruction (optimized out)
299  * @double_cb: callback for second part of the instruction
300  * @l: link on nfp_prog->insns list
301  */
302 struct nfp_insn_meta {
303 	struct bpf_insn insn;
304 	union {
305 		/* pointer ops (ld/st/xadd) */
306 		struct {
307 			struct bpf_reg_state ptr;
308 			struct bpf_insn *paired_st;
309 			s16 ldst_gather_len;
310 			bool ptr_not_const;
311 			struct {
312 				s16 range_start;
313 				s16 range_end;
314 				bool do_init;
315 			} pkt_cache;
316 			bool xadd_over_16bit;
317 			bool xadd_maybe_16bit;
318 		};
319 		/* jump */
320 		struct {
321 			struct nfp_insn_meta *jmp_dst;
322 			bool jump_neg_op;
323 			u32 num_insns_after_br; /* only for BPF-to-BPF calls */
324 		};
325 		/* function calls */
326 		struct {
327 			u32 func_id;
328 			struct bpf_reg_state arg1;
329 			struct nfp_bpf_reg_state arg2;
330 		};
331 		/* We are interested in range info for operands of ALU
332 		 * operations. For example, shift amount, multiplicand and
333 		 * multiplier etc.
334 		 */
335 		struct {
336 			u64 umin_src;
337 			u64 umax_src;
338 			u64 umin_dst;
339 			u64 umax_dst;
340 		};
341 	};
342 	unsigned int off;
343 	unsigned short n;
344 	unsigned short flags;
345 	unsigned short subprog_idx;
346 	bool skip;
347 	instr_cb_t double_cb;
348 
349 	struct list_head l;
350 };
351 
352 #define BPF_SIZE_MASK	0x18
353 
354 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
355 {
356 	return BPF_CLASS(meta->insn.code);
357 }
358 
359 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
360 {
361 	return BPF_SRC(meta->insn.code);
362 }
363 
364 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
365 {
366 	return BPF_OP(meta->insn.code);
367 }
368 
369 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
370 {
371 	return BPF_MODE(meta->insn.code);
372 }
373 
374 static inline bool is_mbpf_alu(const struct nfp_insn_meta *meta)
375 {
376 	return mbpf_class(meta) == BPF_ALU64 || mbpf_class(meta) == BPF_ALU;
377 }
378 
379 static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
380 {
381 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
382 }
383 
384 static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
385 {
386 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
387 }
388 
389 static inline bool is_mbpf_load_pkt(const struct nfp_insn_meta *meta)
390 {
391 	return is_mbpf_load(meta) && meta->ptr.type == PTR_TO_PACKET;
392 }
393 
394 static inline bool is_mbpf_store_pkt(const struct nfp_insn_meta *meta)
395 {
396 	return is_mbpf_store(meta) && meta->ptr.type == PTR_TO_PACKET;
397 }
398 
399 static inline bool is_mbpf_classic_load(const struct nfp_insn_meta *meta)
400 {
401 	u8 code = meta->insn.code;
402 
403 	return BPF_CLASS(code) == BPF_LD &&
404 	       (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND);
405 }
406 
407 static inline bool is_mbpf_classic_store(const struct nfp_insn_meta *meta)
408 {
409 	u8 code = meta->insn.code;
410 
411 	return BPF_CLASS(code) == BPF_ST && BPF_MODE(code) == BPF_MEM;
412 }
413 
414 static inline bool is_mbpf_classic_store_pkt(const struct nfp_insn_meta *meta)
415 {
416 	return is_mbpf_classic_store(meta) && meta->ptr.type == PTR_TO_PACKET;
417 }
418 
419 static inline bool is_mbpf_xadd(const struct nfp_insn_meta *meta)
420 {
421 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_XADD);
422 }
423 
424 static inline bool is_mbpf_mul(const struct nfp_insn_meta *meta)
425 {
426 	return is_mbpf_alu(meta) && mbpf_op(meta) == BPF_MUL;
427 }
428 
429 static inline bool is_mbpf_div(const struct nfp_insn_meta *meta)
430 {
431 	return is_mbpf_alu(meta) && mbpf_op(meta) == BPF_DIV;
432 }
433 
434 static inline bool is_mbpf_helper_call(const struct nfp_insn_meta *meta)
435 {
436 	struct bpf_insn insn = meta->insn;
437 
438 	return insn.code == (BPF_JMP | BPF_CALL) &&
439 		insn.src_reg != BPF_PSEUDO_CALL;
440 }
441 
442 static inline bool is_mbpf_pseudo_call(const struct nfp_insn_meta *meta)
443 {
444 	struct bpf_insn insn = meta->insn;
445 
446 	return insn.code == (BPF_JMP | BPF_CALL) &&
447 		insn.src_reg == BPF_PSEUDO_CALL;
448 }
449 
450 #define STACK_FRAME_ALIGN 64
451 
452 /**
453  * struct nfp_bpf_subprog_info - nfp BPF sub-program (a.k.a. function) info
454  * @stack_depth:	maximum stack depth used by this sub-program
455  * @needs_reg_push:	whether sub-program uses callee-saved registers
456  */
457 struct nfp_bpf_subprog_info {
458 	u16 stack_depth;
459 	u8 needs_reg_push : 1;
460 };
461 
462 /**
463  * struct nfp_prog - nfp BPF program
464  * @bpf: backpointer to the bpf app priv structure
465  * @prog: machine code
466  * @prog_len: number of valid instructions in @prog array
467  * @__prog_alloc_len: alloc size of @prog array
468  * @verifier_meta: temporary storage for verifier's insn meta
469  * @type: BPF program type
470  * @last_bpf_off: address of the last instruction translated from BPF
471  * @tgt_out: jump target for normal exit
472  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
473  * @tgt_call_push_regs: jump target for subroutine for saving R6~R9 to stack
474  * @tgt_call_pop_regs: jump target for subroutine used for restoring R6~R9
475  * @n_translated: number of successfully translated instructions (for errors)
476  * @error: error code if something went wrong
477  * @stack_frame_depth: max stack depth for current frame
478  * @adjust_head_location: if program has single adjust head call - the insn no.
479  * @map_records_cnt: the number of map pointers recorded for this prog
480  * @subprog_cnt: number of sub-programs, including main function
481  * @map_records: the map record pointers from bpf->maps_neutral
482  * @subprog: pointer to an array of objects holding info about sub-programs
483  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
484  */
485 struct nfp_prog {
486 	struct nfp_app_bpf *bpf;
487 
488 	u64 *prog;
489 	unsigned int prog_len;
490 	unsigned int __prog_alloc_len;
491 
492 	struct nfp_insn_meta *verifier_meta;
493 
494 	enum bpf_prog_type type;
495 
496 	unsigned int last_bpf_off;
497 	unsigned int tgt_out;
498 	unsigned int tgt_abort;
499 	unsigned int tgt_call_push_regs;
500 	unsigned int tgt_call_pop_regs;
501 
502 	unsigned int n_translated;
503 	int error;
504 
505 	unsigned int stack_frame_depth;
506 	unsigned int adjust_head_location;
507 
508 	unsigned int map_records_cnt;
509 	unsigned int subprog_cnt;
510 	struct nfp_bpf_neutral_map **map_records;
511 	struct nfp_bpf_subprog_info *subprog;
512 
513 	struct list_head insns;
514 };
515 
516 /**
517  * struct nfp_bpf_vnic - per-vNIC BPF priv structure
518  * @tc_prog:	currently loaded cls_bpf program
519  * @start_off:	address of the first instruction in the memory
520  * @tgt_done:	jump target to get the next packet
521  */
522 struct nfp_bpf_vnic {
523 	struct bpf_prog *tc_prog;
524 	unsigned int start_off;
525 	unsigned int tgt_done;
526 };
527 
528 bool nfp_is_subprog_start(struct nfp_insn_meta *meta);
529 void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
530 int nfp_bpf_jit(struct nfp_prog *prog);
531 bool nfp_bpf_supported_opcode(u8 code);
532 
533 extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
534 
535 struct netdev_bpf;
536 struct nfp_app;
537 struct nfp_net;
538 
539 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn,
540 		struct netdev_bpf *bpf);
541 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
542 			bool old_prog, struct netlink_ext_ack *extack);
543 
544 struct nfp_insn_meta *
545 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
546 		  unsigned int insn_idx, unsigned int n_insns);
547 
548 void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv);
549 
550 unsigned int nfp_bpf_ctrl_cmsg_mtu(struct nfp_app_bpf *bpf);
551 long long int
552 nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map);
553 void
554 nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map);
555 int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
556 				void *next_key);
557 int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
558 			      void *key, void *value, u64 flags);
559 int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key);
560 int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
561 			      void *key, void *value);
562 int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
563 			       void *key, void *next_key);
564 
565 int nfp_bpf_event_output(struct nfp_app_bpf *bpf, const void *data,
566 			 unsigned int len);
567 
568 void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb);
569 void
570 nfp_bpf_ctrl_msg_rx_raw(struct nfp_app *app, const void *data,
571 			unsigned int len);
572 #endif
573