xref: /openbmc/linux/samples/bpf/bpf_insn.h (revision 63705da3)
1 /* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
2 /* eBPF instruction mini library */
3 #ifndef __BPF_INSN_H
4 #define __BPF_INSN_H
5 
6 struct bpf_insn;
7 
8 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
9 
10 #define BPF_ALU64_REG(OP, DST, SRC)				\
11 	((struct bpf_insn) {					\
12 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
13 		.dst_reg = DST,					\
14 		.src_reg = SRC,					\
15 		.off   = 0,					\
16 		.imm   = 0 })
17 
18 #define BPF_ALU32_REG(OP, DST, SRC)				\
19 	((struct bpf_insn) {					\
20 		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
21 		.dst_reg = DST,					\
22 		.src_reg = SRC,					\
23 		.off   = 0,					\
24 		.imm   = 0 })
25 
26 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
27 
28 #define BPF_ALU64_IMM(OP, DST, IMM)				\
29 	((struct bpf_insn) {					\
30 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
31 		.dst_reg = DST,					\
32 		.src_reg = 0,					\
33 		.off   = 0,					\
34 		.imm   = IMM })
35 
36 #define BPF_ALU32_IMM(OP, DST, IMM)				\
37 	((struct bpf_insn) {					\
38 		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
39 		.dst_reg = DST,					\
40 		.src_reg = 0,					\
41 		.off   = 0,					\
42 		.imm   = IMM })
43 
44 /* Short form of mov, dst_reg = src_reg */
45 
46 #define BPF_MOV64_REG(DST, SRC)					\
47 	((struct bpf_insn) {					\
48 		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
49 		.dst_reg = DST,					\
50 		.src_reg = SRC,					\
51 		.off   = 0,					\
52 		.imm   = 0 })
53 
54 #define BPF_MOV32_REG(DST, SRC)					\
55 	((struct bpf_insn) {					\
56 		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
57 		.dst_reg = DST,					\
58 		.src_reg = SRC,					\
59 		.off   = 0,					\
60 		.imm   = 0 })
61 
62 /* Short form of mov, dst_reg = imm32 */
63 
64 #define BPF_MOV64_IMM(DST, IMM)					\
65 	((struct bpf_insn) {					\
66 		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
67 		.dst_reg = DST,					\
68 		.src_reg = 0,					\
69 		.off   = 0,					\
70 		.imm   = IMM })
71 
72 #define BPF_MOV32_IMM(DST, IMM)					\
73 	((struct bpf_insn) {					\
74 		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
75 		.dst_reg = DST,					\
76 		.src_reg = 0,					\
77 		.off   = 0,					\
78 		.imm   = IMM })
79 
80 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
81 #define BPF_LD_IMM64(DST, IMM)					\
82 	BPF_LD_IMM64_RAW(DST, 0, IMM)
83 
84 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
85 	((struct bpf_insn) {					\
86 		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
87 		.dst_reg = DST,					\
88 		.src_reg = SRC,					\
89 		.off   = 0,					\
90 		.imm   = (__u32) (IMM) }),			\
91 	((struct bpf_insn) {					\
92 		.code  = 0, /* zero is reserved opcode */	\
93 		.dst_reg = 0,					\
94 		.src_reg = 0,					\
95 		.off   = 0,					\
96 		.imm   = ((__u64) (IMM)) >> 32 })
97 
98 #ifndef BPF_PSEUDO_MAP_FD
99 # define BPF_PSEUDO_MAP_FD	1
100 #endif
101 
102 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
103 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
104 	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
105 
106 
107 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
108 
109 #define BPF_LD_ABS(SIZE, IMM)					\
110 	((struct bpf_insn) {					\
111 		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
112 		.dst_reg = 0,					\
113 		.src_reg = 0,					\
114 		.off   = 0,					\
115 		.imm   = IMM })
116 
117 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
118 
119 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
120 	((struct bpf_insn) {					\
121 		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
122 		.dst_reg = DST,					\
123 		.src_reg = SRC,					\
124 		.off   = OFF,					\
125 		.imm   = 0 })
126 
127 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
128 
129 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
130 	((struct bpf_insn) {					\
131 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
132 		.dst_reg = DST,					\
133 		.src_reg = SRC,					\
134 		.off   = OFF,					\
135 		.imm   = 0 })
136 
137 /*
138  * Atomic operations:
139  *
140  *   BPF_ADD                  *(uint *) (dst_reg + off16) += src_reg
141  *   BPF_AND                  *(uint *) (dst_reg + off16) &= src_reg
142  *   BPF_OR                   *(uint *) (dst_reg + off16) |= src_reg
143  *   BPF_XOR                  *(uint *) (dst_reg + off16) ^= src_reg
144  *   BPF_ADD | BPF_FETCH      src_reg = atomic_fetch_add(dst_reg + off16, src_reg);
145  *   BPF_AND | BPF_FETCH      src_reg = atomic_fetch_and(dst_reg + off16, src_reg);
146  *   BPF_OR | BPF_FETCH       src_reg = atomic_fetch_or(dst_reg + off16, src_reg);
147  *   BPF_XOR | BPF_FETCH      src_reg = atomic_fetch_xor(dst_reg + off16, src_reg);
148  *   BPF_XCHG                 src_reg = atomic_xchg(dst_reg + off16, src_reg)
149  *   BPF_CMPXCHG              r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg)
150  */
151 
152 #define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF)			\
153 	((struct bpf_insn) {					\
154 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC,	\
155 		.dst_reg = DST,					\
156 		.src_reg = SRC,					\
157 		.off   = OFF,					\
158 		.imm   = OP })
159 
160 /* Legacy alias */
161 #define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF)
162 
163 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
164 
165 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
166 	((struct bpf_insn) {					\
167 		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
168 		.dst_reg = DST,					\
169 		.src_reg = 0,					\
170 		.off   = OFF,					\
171 		.imm   = IMM })
172 
173 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
174 
175 #define BPF_JMP_REG(OP, DST, SRC, OFF)				\
176 	((struct bpf_insn) {					\
177 		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
178 		.dst_reg = DST,					\
179 		.src_reg = SRC,					\
180 		.off   = OFF,					\
181 		.imm   = 0 })
182 
183 /* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
184 
185 #define BPF_JMP32_REG(OP, DST, SRC, OFF)			\
186 	((struct bpf_insn) {					\
187 		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\
188 		.dst_reg = DST,					\
189 		.src_reg = SRC,					\
190 		.off   = OFF,					\
191 		.imm   = 0 })
192 
193 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
194 
195 #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
196 	((struct bpf_insn) {					\
197 		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
198 		.dst_reg = DST,					\
199 		.src_reg = 0,					\
200 		.off   = OFF,					\
201 		.imm   = IMM })
202 
203 /* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
204 
205 #define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\
206 	((struct bpf_insn) {					\
207 		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\
208 		.dst_reg = DST,					\
209 		.src_reg = 0,					\
210 		.off   = OFF,					\
211 		.imm   = IMM })
212 
213 /* Raw code statement block */
214 
215 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
216 	((struct bpf_insn) {					\
217 		.code  = CODE,					\
218 		.dst_reg = DST,					\
219 		.src_reg = SRC,					\
220 		.off   = OFF,					\
221 		.imm   = IMM })
222 
223 /* Program exit */
224 
225 #define BPF_EXIT_INSN()						\
226 	((struct bpf_insn) {					\
227 		.code  = BPF_JMP | BPF_EXIT,			\
228 		.dst_reg = 0,					\
229 		.src_reg = 0,					\
230 		.off   = 0,					\
231 		.imm   = 0 })
232 
233 #endif
234