1 /*
2  * Copyright (C) 2016 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 #include "../nfp_net.h"
45 
46 /* For branch fixup logic use up-most byte of branch instruction as scratch
47  * area.  Remember to clear this before sending instructions to HW!
48  */
49 #define OP_BR_SPECIAL	0xff00000000000000ULL
50 
51 enum br_special {
52 	OP_BR_NORMAL = 0,
53 	OP_BR_GO_OUT,
54 	OP_BR_GO_ABORT,
55 };
56 
57 enum static_regs {
58 	STATIC_REG_IMM		= 21, /* Bank AB */
59 	STATIC_REG_STACK	= 22, /* Bank A */
60 	STATIC_REG_PKT_LEN	= 22, /* Bank B */
61 };
62 
63 enum pkt_vec {
64 	PKT_VEC_PKT_LEN		= 0,
65 	PKT_VEC_PKT_PTR		= 2,
66 };
67 
68 #define pv_len(np)	reg_lm(1, PKT_VEC_PKT_LEN)
69 #define pv_ctm_ptr(np)	reg_lm(1, PKT_VEC_PKT_PTR)
70 
71 #define stack_reg(np)	reg_a(STATIC_REG_STACK)
72 #define stack_imm(np)	imm_b(np)
73 #define plen_reg(np)	reg_b(STATIC_REG_PKT_LEN)
74 #define pptr_reg(np)	pv_ctm_ptr(np)
75 #define imm_a(np)	reg_a(STATIC_REG_IMM)
76 #define imm_b(np)	reg_b(STATIC_REG_IMM)
77 #define imm_both(np)	reg_both(STATIC_REG_IMM)
78 
79 #define NFP_BPF_ABI_FLAGS	reg_imm(0)
80 #define   NFP_BPF_ABI_FLAG_MARK	1
81 
82 struct nfp_prog;
83 struct nfp_insn_meta;
84 typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);
85 
86 #define nfp_prog_first_meta(nfp_prog)					\
87 	list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
88 #define nfp_prog_last_meta(nfp_prog)					\
89 	list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
90 #define nfp_meta_next(meta)	list_next_entry(meta, l)
91 #define nfp_meta_prev(meta)	list_prev_entry(meta, l)
92 
93 /**
94  * struct nfp_insn_meta - BPF instruction wrapper
95  * @insn: BPF instruction
96  * @ptr: pointer type for memory operations
97  * @ptr_not_const: pointer is not always constant
98  * @off: index of first generated machine instruction (in nfp_prog.prog)
99  * @n: eBPF instruction number
100  * @skip: skip this instruction (optimized out)
101  * @double_cb: callback for second part of the instruction
102  * @l: link on nfp_prog->insns list
103  */
104 struct nfp_insn_meta {
105 	struct bpf_insn insn;
106 	struct bpf_reg_state ptr;
107 	bool ptr_not_const;
108 	unsigned int off;
109 	unsigned short n;
110 	bool skip;
111 	instr_cb_t double_cb;
112 
113 	struct list_head l;
114 };
115 
116 #define BPF_SIZE_MASK	0x18
117 
118 static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
119 {
120 	return BPF_CLASS(meta->insn.code);
121 }
122 
123 static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
124 {
125 	return BPF_SRC(meta->insn.code);
126 }
127 
128 static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
129 {
130 	return BPF_OP(meta->insn.code);
131 }
132 
133 static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
134 {
135 	return BPF_MODE(meta->insn.code);
136 }
137 
138 /**
139  * struct nfp_prog - nfp BPF program
140  * @prog: machine code
141  * @prog_len: number of valid instructions in @prog array
142  * @__prog_alloc_len: alloc size of @prog array
143  * @type: BPF program type
144  * @num_regs: number of registers used by this program
145  * @regs_per_thread: number of basic registers allocated per thread
146  * @start_off: address of the first instruction in the memory
147  * @tgt_out: jump target for normal exit
148  * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
149  * @tgt_done: jump target to get the next packet
150  * @n_translated: number of successfully translated instructions (for errors)
151  * @error: error code if something went wrong
152  * @stack_depth: max stack depth from the verifier
153  * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
154  */
155 struct nfp_prog {
156 	u64 *prog;
157 	unsigned int prog_len;
158 	unsigned int __prog_alloc_len;
159 
160 	enum bpf_prog_type type;
161 
162 	unsigned int num_regs;
163 	unsigned int regs_per_thread;
164 
165 	unsigned int start_off;
166 	unsigned int tgt_out;
167 	unsigned int tgt_abort;
168 	unsigned int tgt_done;
169 
170 	unsigned int n_translated;
171 	int error;
172 
173 	unsigned int stack_depth;
174 
175 	struct list_head insns;
176 };
177 
178 struct nfp_bpf_result {
179 	unsigned int n_instr;
180 	bool dense_mode;
181 };
182 
183 int
184 nfp_bpf_jit(struct bpf_prog *filter, void *prog,
185 	    unsigned int prog_start, unsigned int prog_done,
186 	    unsigned int prog_sz, struct nfp_bpf_result *res);
187 
188 int nfp_prog_verify(struct nfp_prog *nfp_prog, struct bpf_prog *prog);
189 
190 struct nfp_net;
191 struct tc_cls_bpf_offload;
192 
193 int nfp_net_bpf_offload(struct nfp_net *nn, struct tc_cls_bpf_offload *cls_bpf);
194 
195 #endif
196