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/list.h>
41 #include <linux/types.h>
42 
43 #include "../nfp_asm.h"
44 
45 /* For branch fixup logic use up-most byte of branch instruction as scratch
46  * area.  Remember to clear this before sending instructions to HW!
47  */
48 #define OP_BR_SPECIAL	0xff00000000000000ULL
49 
50 enum br_special {
51 	OP_BR_NORMAL = 0,
52 	OP_BR_GO_OUT,
53 	OP_BR_GO_ABORT,
54 };
55 
56 enum static_regs {
57 	STATIC_REG_IMM		= 21, /* Bank AB */
58 	STATIC_REG_STACK	= 22, /* Bank A */
59 	STATIC_REG_PKT_LEN	= 22, /* Bank B */
60 };
61 
62 enum pkt_vec {
63 	PKT_VEC_PKT_LEN		= 0,
64 	PKT_VEC_PKT_PTR		= 2,
65 };
66 
67 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
68 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
69 
70 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
71 #define stack_imm(np)	imm_b(np)
72 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
73 #define pptr_reg(np)	pv_ctm_ptr(np)
74 #define imm_a(np)	reg_a(STATIC_REG_IMM)
75 #define imm_b(np)	reg_b(STATIC_REG_IMM)
76 #define imm_both(np)	reg_both(STATIC_REG_IMM)
77 
78 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
79 #define   NFP_BPF_ABI_FLAG_MARK	1
80 
81 /**
82  * struct nfp_app_bpf - bpf app priv structure
83  * @app:		backpointer to the app
84  */
85 struct nfp_app_bpf {
86 	struct nfp_app *app;
87 };
88 
89 struct nfp_prog;
90 struct nfp_insn_meta;
91 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
92 
93 #define nfp_prog_first_meta(nfp_prog)					\
94 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
95 #define nfp_prog_last_meta(nfp_prog)					\
96 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
97 #define nfp_meta_next(meta)	list_next_entry(meta, l)
98 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
99 
100 #define FLAG_INSN_IS_JUMP_DST	BIT(0)
101 
102 /**
103  * struct nfp_insn_meta - BPF instruction wrapper
104  * @insn: BPF instruction
105  * @ptr: pointer type for memory operations
106  * @ldst_gather_len: memcpy length gathered from load/store sequence
107  * @paired_st: the paired store insn at the head of the sequence
108  * @ptr_not_const: pointer is not always constant
109  * @jmp_dst: destination info for jump instructions
110  * @off: index of first generated machine instruction (in nfp_prog.prog)
111  * @n: eBPF instruction number
112  * @flags: eBPF instruction extra optimization flags
113  * @skip: skip this instruction (optimized out)
114  * @double_cb: callback for second part of the instruction
115  * @l: link on nfp_prog->insns list
116  */
117 struct nfp_insn_meta {
118 	struct bpf_insn insn;
119 	union {
120 		struct {
121 			struct bpf_reg_state ptr;
122 			struct bpf_insn *paired_st;
123 			s16 ldst_gather_len;
124 			bool ptr_not_const;
125 		};
126 		struct nfp_insn_meta *jmp_dst;
127 	};
128 	unsigned int off;
129 	unsigned short n;
130 	unsigned short flags;
131 	bool skip;
132 	instr_cb_t double_cb;
133 
134 	struct list_head l;
135 };
136 
137 #define BPF_SIZE_MASK	0x18
138 
139 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
140 {
141 	return BPF_CLASS(meta->insn.code);
142 }
143 
144 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
145 {
146 	return BPF_SRC(meta->insn.code);
147 }
148 
149 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
150 {
151 	return BPF_OP(meta->insn.code);
152 }
153 
154 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
155 {
156 	return BPF_MODE(meta->insn.code);
157 }
158 
159 static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
160 {
161 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
162 }
163 
164 static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
165 {
166 	return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
167 }
168 
169 /**
170  * struct nfp_prog - nfp BPF program
171  * @bpf: backpointer to the bpf app priv structure
172  * @prog: machine code
173  * @prog_len: number of valid instructions in @prog array
174  * @__prog_alloc_len: alloc size of @prog array
175  * @verifier_meta: temporary storage for verifier's insn meta
176  * @type: BPF program type
177  * @start_off: address of the first instruction in the memory
178  * @last_bpf_off: address of the last instruction translated from BPF
179  * @tgt_out: jump target for normal exit
180  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
181  * @tgt_done: jump target to get the next packet
182  * @n_translated: number of successfully translated instructions (for errors)
183  * @error: error code if something went wrong
184  * @stack_depth: max stack depth from the verifier
185  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
186  */
187 struct nfp_prog {
188 	struct nfp_app_bpf *bpf;
189 
190 	u64 *prog;
191 	unsigned int prog_len;
192 	unsigned int __prog_alloc_len;
193 
194 	struct nfp_insn_meta *verifier_meta;
195 
196 	enum bpf_prog_type type;
197 
198 	unsigned int start_off;
199 	unsigned int last_bpf_off;
200 	unsigned int tgt_out;
201 	unsigned int tgt_abort;
202 	unsigned int tgt_done;
203 
204 	unsigned int n_translated;
205 	int error;
206 
207 	unsigned int stack_depth;
208 
209 	struct list_head insns;
210 };
211 
212 int nfp_bpf_jit(struct nfp_prog *prog);
213 
214 extern const struct bpf_ext_analyzer_ops nfp_bpf_analyzer_ops;
215 
216 struct netdev_bpf;
217 struct nfp_app;
218 struct nfp_net;
219 
220 int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
221 			bool old_prog);
222 
223 int nfp_bpf_verifier_prep(struct nfp_app *app, struct nfp_net *nn,
224 			  struct netdev_bpf *bpf);
225 int nfp_bpf_translate(struct nfp_app *app, struct nfp_net *nn,
226 		      struct bpf_prog *prog);
227 int nfp_bpf_destroy(struct nfp_app *app, struct nfp_net *nn,
228 		    struct bpf_prog *prog);
229 struct nfp_insn_meta *
230 nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
231 		  unsigned int insn_idx, unsigned int n_insns);
232 #endif
233