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_IMM		= 21, /* Bank AB */
76 	STATIC_REG_STACK	= 22, /* Bank A */
77 	STATIC_REG_PKT_LEN	= 22, /* Bank B */
78 };
79 
80 enum pkt_vec {
81 	PKT_VEC_PKT_LEN		= 0,
82 	PKT_VEC_PKT_PTR		= 2,
83 };
84 
85 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
86 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
87 
88 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
89 #define stack_imm(np)	imm_b(np)
90 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
91 #define pptr_reg(np)	pv_ctm_ptr(np)
92 #define imm_a(np)	reg_a(STATIC_REG_IMM)
93 #define imm_b(np)	reg_b(STATIC_REG_IMM)
94 #define imm_both(np)	reg_both(STATIC_REG_IMM)
95 
96 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
97 #define   NFP_BPF_ABI_FLAG_MARK	1
98 
99 /**
100  * struct nfp_app_bpf - bpf app priv structure
101  * @app:		backpointer to the app
102  *
103  * @tag_allocator:	bitmap of control message tags in use
104  * @tag_alloc_next:	next tag bit to allocate
105  * @tag_alloc_last:	next tag bit to be freed
106  *
107  * @cmsg_replies:	received cmsg replies waiting to be consumed
108  * @cmsg_wq:		work queue for waiting for cmsg replies
109  *
110  * @map_list:		list of offloaded maps
111  *
112  * @adjust_head:	adjust head capability
113  * @flags:		extra flags for adjust head
114  * @off_min:		minimal packet offset within buffer required
115  * @off_max:		maximum packet offset within buffer required
116  * @guaranteed_sub:	amount of negative adjustment guaranteed possible
117  * @guaranteed_add:	amount of positive adjustment guaranteed possible
118  *
119  * @maps:		map capability
120  * @types:		supported map types
121  * @max_maps:		max number of maps supported
122  * @max_elems:		max number of entries in each map
123  * @max_key_sz:		max size of map key
124  * @max_val_sz:		max size of map value
125  * @max_elem_sz:	max size of map entry (key + value)
126  *
127  * @helpers:		helper addressess for various calls
128  * @map_lookup:		map lookup helper address
129  */
130 struct nfp_app_bpf {
131 	struct nfp_app *app;
132 
133 	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
134 	u16 tag_alloc_next;
135 	u16 tag_alloc_last;
136 
137 	struct sk_buff_head cmsg_replies;
138 	struct wait_queue_head cmsg_wq;
139 
140 	struct list_head map_list;
141 
142 	struct nfp_bpf_cap_adjust_head {
143 		u32 flags;
144 		int off_min;
145 		int off_max;
146 		int guaranteed_sub;
147 		int guaranteed_add;
148 	} adjust_head;
149 
150 	struct {
151 		u32 types;
152 		u32 max_maps;
153 		u32 max_elems;
154 		u32 max_key_sz;
155 		u32 max_val_sz;
156 		u32 max_elem_sz;
157 	} maps;
158 
159 	struct {
160 		u32 map_lookup;
161 	} helpers;
162 };
163 
164 /**
165  * struct nfp_bpf_map - private per-map data attached to BPF maps for offload
166  * @offmap:	pointer to the offloaded BPF map
167  * @bpf:	back pointer to bpf app private structure
168  * @tid:	table id identifying map on datapath
169  * @l:		link on the nfp_app_bpf->map_list list
170  */
171 struct nfp_bpf_map {
172 	struct bpf_offloaded_map *offmap;
173 	struct nfp_app_bpf *bpf;
174 	u32 tid;
175 	struct list_head l;
176 };
177 
178 struct nfp_prog;
179 struct nfp_insn_meta;
180 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
181 
182 #define nfp_prog_first_meta(nfp_prog)					\
183 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
184 #define nfp_prog_last_meta(nfp_prog)					\
185 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
186 #define nfp_meta_next(meta)	list_next_entry(meta, l)
187 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
188 
189 #define FLAG_INSN_IS_JUMP_DST	BIT(0)
190 
191 /**
192  * struct nfp_insn_meta - BPF instruction wrapper
193  * @insn: BPF instruction
194  * @ptr: pointer type for memory operations
195  * @ldst_gather_len: memcpy length gathered from load/store sequence
196  * @paired_st: the paired store insn at the head of the sequence
197  * @ptr_not_const: pointer is not always constant
198  * @jmp_dst: destination info for jump instructions
199  * @func_id: function id for call instructions
200  * @arg1: arg1 for call instructions
201  * @arg2: arg2 for call instructions
202  * @arg2_var_off: arg2 changes stack offset on different paths
203  * @off: index of first generated machine instruction (in nfp_prog.prog)
204  * @n: eBPF instruction number
205  * @flags: eBPF instruction extra optimization flags
206  * @skip: skip this instruction (optimized out)
207  * @double_cb: callback for second part of the instruction
208  * @l: link on nfp_prog->insns list
209  */
210 struct nfp_insn_meta {
211 	struct bpf_insn insn;
212 	union {
213 		struct {
214 			struct bpf_reg_state ptr;
215 			struct bpf_insn *paired_st;
216 			s16 ldst_gather_len;
217 			bool ptr_not_const;
218 		};
219 		struct nfp_insn_meta *jmp_dst;
220 		struct {
221 			u32 func_id;
222 			struct bpf_reg_state arg1;
223 			struct bpf_reg_state arg2;
224 			bool arg2_var_off;
225 		};
226 	};
227 	unsigned int off;
228 	unsigned short n;
229 	unsigned short flags;
230 	bool skip;
231 	instr_cb_t double_cb;
232 
233 	struct list_head l;
234 };
235 
236 #define BPF_SIZE_MASK	0x18
237 
238 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
239 {
240 	return BPF_CLASS(meta->insn.code);
241 }
242 
243 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
244 {
245 	return BPF_SRC(meta->insn.code);
246 }
247 
248 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
249 {
250 	return BPF_OP(meta->insn.code);
251 }
252 
253 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
254 {
255 	return BPF_MODE(meta->insn.code);
256 }
257 
258 static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
259 {
260 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
261 }
262 
263 static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
264 {
265 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
266 }
267 
268 /**
269  * struct nfp_prog - nfp BPF program
270  * @bpf: backpointer to the bpf app priv structure
271  * @prog: machine code
272  * @prog_len: number of valid instructions in @prog array
273  * @__prog_alloc_len: alloc size of @prog array
274  * @verifier_meta: temporary storage for verifier's insn meta
275  * @type: BPF program type
276  * @last_bpf_off: address of the last instruction translated from BPF
277  * @tgt_out: jump target for normal exit
278  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
279  * @n_translated: number of successfully translated instructions (for errors)
280  * @error: error code if something went wrong
281  * @stack_depth: max stack depth from the verifier
282  * @adjust_head_location: if program has single adjust head call - the insn no.
283  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
284  */
285 struct nfp_prog {
286 	struct nfp_app_bpf *bpf;
287 
288 	u64 *prog;
289 	unsigned int prog_len;
290 	unsigned int __prog_alloc_len;
291 
292 	struct nfp_insn_meta *verifier_meta;
293 
294 	enum bpf_prog_type type;
295 
296 	unsigned int last_bpf_off;
297 	unsigned int tgt_out;
298 	unsigned int tgt_abort;
299 
300 	unsigned int n_translated;
301 	int error;
302 
303 	unsigned int stack_depth;
304 	unsigned int adjust_head_location;
305 
306 	struct list_head insns;
307 };
308 
309 /**
310  * struct nfp_bpf_vnic - per-vNIC BPF priv structure
311  * @tc_prog:	currently loaded cls_bpf program
312  * @start_off:	address of the first instruction in the memory
313  * @tgt_done:	jump target to get the next packet
314  */
315 struct nfp_bpf_vnic {
316 	struct bpf_prog *tc_prog;
317 	unsigned int start_off;
318 	unsigned int tgt_done;
319 };
320 
321 void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
322 int nfp_bpf_jit(struct nfp_prog *prog);
323 
324 extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
325 
326 struct netdev_bpf;
327 struct nfp_app;
328 struct nfp_net;
329 
330 int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn,
331 		struct netdev_bpf *bpf);
332 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
333 			bool old_prog);
334 
335 struct nfp_insn_meta *
336 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
337 		  unsigned int insn_idx, unsigned int n_insns);
338 
339 void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv);
340 
341 long long int
342 nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map);
343 void
344 nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map);
345 int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
346 				void *next_key);
347 int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
348 			      void *key, void *value, u64 flags);
349 int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key);
350 int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
351 			      void *key, void *value);
352 int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
353 			       void *key, void *next_key);
354 
355 void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb);
356 #endif
357