1 /*
2  * Copyright (C) 2016-2017 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/skbuff.h>
43 #include <linux/types.h>
44 #include <linux/wait.h>
45 
46 #include "../nfp_asm.h"
47 #include "fw.h"
48 
49 /* For relocation logic use up-most byte of branch instruction as scratch
50  * area.  Remember to clear this before sending instructions to HW!
51  */
52 #define OP_RELO_TYPE	0xff00000000000000ULL
53 
54 enum nfp_relo_type {
55 	RELO_NONE = 0,
56 	/* standard internal jumps */
57 	RELO_BR_REL,
58 	/* internal jumps to parts of the outro */
59 	RELO_BR_GO_OUT,
60 	RELO_BR_GO_ABORT,
61 	/* external jumps to fixed addresses */
62 	RELO_BR_NEXT_PKT,
63 	RELO_BR_HELPER,
64 	/* immediate relocation against load address */
65 	RELO_IMMED_REL,
66 };
67 
68 /* To make absolute relocated branches (branches other than RELO_BR_REL)
69  * distinguishable in user space dumps from normal jumps, add a large offset
70  * to them.
71  */
72 #define BR_OFF_RELO		15000
73 
74 enum static_regs {
75 	STATIC_REG_IMMA		= 20, /* Bank AB */
76 	STATIC_REG_IMM		= 21, /* Bank AB */
77 	STATIC_REG_STACK	= 22, /* Bank A */
78 	STATIC_REG_PKT_LEN	= 22, /* Bank B */
79 };
80 
81 enum pkt_vec {
82 	PKT_VEC_PKT_LEN		= 0,
83 	PKT_VEC_PKT_PTR		= 2,
84 };
85 
86 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
87 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
88 
89 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
90 #define stack_imm(np)	imm_b(np)
91 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
92 #define pptr_reg(np)	pv_ctm_ptr(np)
93 #define imm_a(np)	reg_a(STATIC_REG_IMM)
94 #define imm_b(np)	reg_b(STATIC_REG_IMM)
95 #define imma_a(np)	reg_a(STATIC_REG_IMMA)
96 #define imma_b(np)	reg_b(STATIC_REG_IMMA)
97 #define imm_both(np)	reg_both(STATIC_REG_IMM)
98 
99 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
100 #define   NFP_BPF_ABI_FLAG_MARK	1
101 
102 /**
103  * struct nfp_app_bpf - bpf app priv structure
104  * @app:		backpointer to the app
105  *
106  * @tag_allocator:	bitmap of control message tags in use
107  * @tag_alloc_next:	next tag bit to allocate
108  * @tag_alloc_last:	next tag bit to be freed
109  *
110  * @cmsg_replies:	received cmsg replies waiting to be consumed
111  * @cmsg_wq:		work queue for waiting for cmsg replies
112  *
113  * @map_list:		list of offloaded maps
114  * @maps_in_use:	number of currently offloaded maps
115  * @map_elems_in_use:	number of elements allocated to offloaded maps
116  *
117  * @adjust_head:	adjust head capability
118  * @adjust_head.flags:		extra flags for adjust head
119  * @adjust_head.off_min:	minimal packet offset within buffer required
120  * @adjust_head.off_max:	maximum packet offset within buffer required
121  * @adjust_head.guaranteed_sub:	negative adjustment guaranteed possible
122  * @adjust_head.guaranteed_add:	positive adjustment guaranteed possible
123  *
124  * @maps:		map capability
125  * @maps.types:			supported map types
126  * @maps.max_maps:		max number of maps supported
127  * @maps.max_elems:		max number of entries in each map
128  * @maps.max_key_sz:		max size of map key
129  * @maps.max_val_sz:		max size of map value
130  * @maps.max_elem_sz:		max size of map entry (key + value)
131  *
132  * @helpers:		helper addressess for various calls
133  * @helpers.map_lookup:		map lookup helper address
134  * @helpers.map_update:		map update helper address
135  * @helpers.map_delete:		map delete helper address
136  */
137 struct nfp_app_bpf {
138 	struct nfp_app *app;
139 
140 	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
141 	u16 tag_alloc_next;
142 	u16 tag_alloc_last;
143 
144 	struct sk_buff_head cmsg_replies;
145 	struct wait_queue_head cmsg_wq;
146 
147 	struct list_head map_list;
148 	unsigned int maps_in_use;
149 	unsigned int map_elems_in_use;
150 
151 	struct nfp_bpf_cap_adjust_head {
152 		u32 flags;
153 		int off_min;
154 		int off_max;
155 		int guaranteed_sub;
156 		int guaranteed_add;
157 	} adjust_head;
158 
159 	struct {
160 		u32 types;
161 		u32 max_maps;
162 		u32 max_elems;
163 		u32 max_key_sz;
164 		u32 max_val_sz;
165 		u32 max_elem_sz;
166 	} maps;
167 
168 	struct {
169 		u32 map_lookup;
170 		u32 map_update;
171 		u32 map_delete;
172 	} helpers;
173 };
174 
175 enum nfp_bpf_map_use {
176 	NFP_MAP_UNUSED = 0,
177 	NFP_MAP_USE_READ,
178 	NFP_MAP_USE_WRITE,
179 	NFP_MAP_USE_ATOMIC_CNT,
180 };
181 
182 /**
183  * struct nfp_bpf_map - private per-map data attached to BPF maps for offload
184  * @offmap:	pointer to the offloaded BPF map
185  * @bpf:	back pointer to bpf app private structure
186  * @tid:	table id identifying map on datapath
187  * @l:		link on the nfp_app_bpf->map_list list
188  * @use_map:	map of how the value is used (in 4B chunks)
189  */
190 struct nfp_bpf_map {
191 	struct bpf_offloaded_map *offmap;
192 	struct nfp_app_bpf *bpf;
193 	u32 tid;
194 	struct list_head l;
195 	enum nfp_bpf_map_use use_map[];
196 };
197 
198 struct nfp_prog;
199 struct nfp_insn_meta;
200 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
201 
202 #define nfp_prog_first_meta(nfp_prog)					\
203 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
204 #define nfp_prog_last_meta(nfp_prog)					\
205 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
206 #define nfp_meta_next(meta)	list_next_entry(meta, l)
207 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
208 
209 /**
210  * struct nfp_bpf_reg_state - register state for calls
211  * @reg: BPF register state from latest path
212  * @var_off: for stack arg - changes stack offset on different paths
213  */
214 struct nfp_bpf_reg_state {
215 	struct bpf_reg_state reg;
216 	bool var_off;
217 };
218 
219 #define FLAG_INSN_IS_JUMP_DST	BIT(0)
220 
221 /**
222  * struct nfp_insn_meta - BPF instruction wrapper
223  * @insn: BPF instruction
224  * @ptr: pointer type for memory operations
225  * @ldst_gather_len: memcpy length gathered from load/store sequence
226  * @paired_st: the paired store insn at the head of the sequence
227  * @ptr_not_const: pointer is not always constant
228  * @pkt_cache: packet data cache information
229  * @pkt_cache.range_start: start offset for associated packet data cache
230  * @pkt_cache.range_end: end offset for associated packet data cache
231  * @pkt_cache.do_init: this read needs to initialize packet data cache
232  * @xadd_over_16bit: 16bit immediate is not guaranteed
233  * @xadd_maybe_16bit: 16bit immediate is possible
234  * @jmp_dst: destination info for jump instructions
235  * @func_id: function id for call instructions
236  * @arg1: arg1 for call instructions
237  * @arg2: arg2 for call instructions
238  * @off: index of first generated machine instruction (in nfp_prog.prog)
239  * @n: eBPF instruction number
240  * @flags: eBPF instruction extra optimization flags
241  * @skip: skip this instruction (optimized out)
242  * @double_cb: callback for second part of the instruction
243  * @l: link on nfp_prog->insns list
244  */
245 struct nfp_insn_meta {
246 	struct bpf_insn insn;
247 	union {
248 		/* pointer ops (ld/st/xadd) */
249 		struct {
250 			struct bpf_reg_state ptr;
251 			struct bpf_insn *paired_st;
252 			s16 ldst_gather_len;
253 			bool ptr_not_const;
254 			struct {
255 				s16 range_start;
256 				s16 range_end;
257 				bool do_init;
258 			} pkt_cache;
259 			bool xadd_over_16bit;
260 			bool xadd_maybe_16bit;
261 		};
262 		/* jump */
263 		struct nfp_insn_meta *jmp_dst;
264 		/* function calls */
265 		struct {
266 			u32 func_id;
267 			struct bpf_reg_state arg1;
268 			struct nfp_bpf_reg_state arg2;
269 		};
270 	};
271 	unsigned int off;
272 	unsigned short n;
273 	unsigned short flags;
274 	bool skip;
275 	instr_cb_t double_cb;
276 
277 	struct list_head l;
278 };
279 
280 #define BPF_SIZE_MASK	0x18
281 
282 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
283 {
284 	return BPF_CLASS(meta->insn.code);
285 }
286 
287 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
288 {
289 	return BPF_SRC(meta->insn.code);
290 }
291 
292 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
293 {
294 	return BPF_OP(meta->insn.code);
295 }
296 
297 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
298 {
299 	return BPF_MODE(meta->insn.code);
300 }
301 
302 static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
303 {
304 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
305 }
306 
307 static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
308 {
309 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
310 }
311 
312 static inline bool is_mbpf_load_pkt(const struct nfp_insn_meta *meta)
313 {
314 	return is_mbpf_load(meta) && meta->ptr.type == PTR_TO_PACKET;
315 }
316 
317 static inline bool is_mbpf_store_pkt(const struct nfp_insn_meta *meta)
318 {
319 	return is_mbpf_store(meta) && meta->ptr.type == PTR_TO_PACKET;
320 }
321 
322 static inline bool is_mbpf_classic_load(const struct nfp_insn_meta *meta)
323 {
324 	u8 code = meta->insn.code;
325 
326 	return BPF_CLASS(code) == BPF_LD &&
327 	       (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND);
328 }
329 
330 static inline bool is_mbpf_classic_store(const struct nfp_insn_meta *meta)
331 {
332 	u8 code = meta->insn.code;
333 
334 	return BPF_CLASS(code) == BPF_ST && BPF_MODE(code) == BPF_MEM;
335 }
336 
337 static inline bool is_mbpf_classic_store_pkt(const struct nfp_insn_meta *meta)
338 {
339 	return is_mbpf_classic_store(meta) && meta->ptr.type == PTR_TO_PACKET;
340 }
341 
342 static inline bool is_mbpf_xadd(const struct nfp_insn_meta *meta)
343 {
344 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_XADD);
345 }
346 
347 /**
348  * struct nfp_prog - nfp BPF program
349  * @bpf: backpointer to the bpf app priv structure
350  * @prog: machine code
351  * @prog_len: number of valid instructions in @prog array
352  * @__prog_alloc_len: alloc size of @prog array
353  * @verifier_meta: temporary storage for verifier's insn meta
354  * @type: BPF program type
355  * @last_bpf_off: address of the last instruction translated from BPF
356  * @tgt_out: jump target for normal exit
357  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
358  * @n_translated: number of successfully translated instructions (for errors)
359  * @error: error code if something went wrong
360  * @stack_depth: max stack depth from the verifier
361  * @adjust_head_location: if program has single adjust head call - the insn no.
362  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
363  */
364 struct nfp_prog {
365 	struct nfp_app_bpf *bpf;
366 
367 	u64 *prog;
368 	unsigned int prog_len;
369 	unsigned int __prog_alloc_len;
370 
371 	struct nfp_insn_meta *verifier_meta;
372 
373 	enum bpf_prog_type type;
374 
375 	unsigned int last_bpf_off;
376 	unsigned int tgt_out;
377 	unsigned int tgt_abort;
378 
379 	unsigned int n_translated;
380 	int error;
381 
382 	unsigned int stack_depth;
383 	unsigned int adjust_head_location;
384 
385 	struct list_head insns;
386 };
387 
388 /**
389  * struct nfp_bpf_vnic - per-vNIC BPF priv structure
390  * @tc_prog:	currently loaded cls_bpf program
391  * @start_off:	address of the first instruction in the memory
392  * @tgt_done:	jump target to get the next packet
393  */
394 struct nfp_bpf_vnic {
395 	struct bpf_prog *tc_prog;
396 	unsigned int start_off;
397 	unsigned int tgt_done;
398 };
399 
400 void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
401 int nfp_bpf_jit(struct nfp_prog *prog);
402 bool nfp_bpf_supported_opcode(u8 code);
403 
404 extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
405 
406 struct netdev_bpf;
407 struct nfp_app;
408 struct nfp_net;
409 
410 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn,
411 		struct netdev_bpf *bpf);
412 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
413 			bool old_prog, struct netlink_ext_ack *extack);
414 
415 struct nfp_insn_meta *
416 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
417 		  unsigned int insn_idx, unsigned int n_insns);
418 
419 void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv);
420 
421 long long int
422 nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map);
423 void
424 nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map);
425 int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
426 				void *next_key);
427 int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
428 			      void *key, void *value, u64 flags);
429 int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key);
430 int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
431 			      void *key, void *value);
432 int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
433 			       void *key, void *next_key);
434 
435 void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb);
436 #endif
437