1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Just-In-Time compiler for BPF filters on MIPS
 4 *
 5 * Copyright (c) 2014 Imagination Technologies Ltd.
 6 * Author: Markos Chandras <markos.chandras@imgtec.com>
 7 */
 8
 9#ifndef BPF_JIT_MIPS_OP_H
10#define BPF_JIT_MIPS_OP_H
11
12/* Registers used by JIT */
13#define MIPS_R_ZERO	0
14#define MIPS_R_V0	2
15#define MIPS_R_A0	4
16#define MIPS_R_A1	5
17#define MIPS_R_T4	12
18#define MIPS_R_T5	13
19#define MIPS_R_T6	14
20#define MIPS_R_T7	15
21#define MIPS_R_S0	16
22#define MIPS_R_S1	17
23#define MIPS_R_S2	18
24#define MIPS_R_S3	19
25#define MIPS_R_S4	20
26#define MIPS_R_S5	21
27#define MIPS_R_S6	22
28#define MIPS_R_S7	23
29#define MIPS_R_SP	29
30#define MIPS_R_RA	31
31
32/* Conditional codes */
33#define MIPS_COND_EQ	0x1
34#define MIPS_COND_GE	(0x1 << 1)
35#define MIPS_COND_GT	(0x1 << 2)
36#define MIPS_COND_NE	(0x1 << 3)
37#define MIPS_COND_ALL	(0x1 << 4)
38/* Conditionals on X register or K immediate */
39#define MIPS_COND_X	(0x1 << 5)
40#define MIPS_COND_K	(0x1 << 6)
41
42#define r_ret	MIPS_R_V0
43
44/*
45 * Use 2 scratch registers to avoid pipeline interlocks.
46 * There is no overhead during epilogue and prologue since
47 * any of the $s0-$s6 registers will only be preserved if
48 * they are going to actually be used.
49 */
50#define r_skb_hl	MIPS_R_S0 /* skb header length */
51#define r_skb_data	MIPS_R_S1 /* skb actual data */
52#define r_off		MIPS_R_S2
53#define r_A		MIPS_R_S3
54#define r_X		MIPS_R_S4
55#define r_skb		MIPS_R_S5
56#define r_M		MIPS_R_S6
57#define r_skb_len	MIPS_R_S7
58#define r_s0		MIPS_R_T4 /* scratch reg 1 */
59#define r_s1		MIPS_R_T5 /* scratch reg 2 */
60#define r_tmp_imm	MIPS_R_T6 /* No need to preserve this */
61#define r_tmp		MIPS_R_T7 /* No need to preserve this */
62#define r_zero		MIPS_R_ZERO
63#define r_sp		MIPS_R_SP
64#define r_ra		MIPS_R_RA
65
66#ifndef __ASSEMBLY__
67
68/* Declare ASM helpers */
69
70#define DECLARE_LOAD_FUNC(func) \
71	extern u8 func(unsigned long *skb, int offset); \
72	extern u8 func##_negative(unsigned long *skb, int offset); \
73	extern u8 func##_positive(unsigned long *skb, int offset)
74
75DECLARE_LOAD_FUNC(sk_load_word);
76DECLARE_LOAD_FUNC(sk_load_half);
77DECLARE_LOAD_FUNC(sk_load_byte);
78
79#endif
80
81#endif /* BPF_JIT_MIPS_OP_H */