1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * several functions that help interpret ARC instructions
4  * used for unaligned accesses, kprobes and kgdb
5  *
6  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
7  */
8 
9 #ifndef __ARC_DISASM_H__
10 #define __ARC_DISASM_H__
11 
12 enum {
13 	op_Bcc = 0, op_BLcc = 1, op_LD = 2, op_ST = 3, op_MAJOR_4 = 4,
14 	op_MAJOR_5 = 5, op_LD_ADD = 12, op_ADD_SUB_SHIFT = 13,
15 	op_ADD_MOV_CMP = 14, op_S = 15, op_LD_S = 16, op_LDB_S = 17,
16 	op_LDW_S = 18, op_LDWX_S = 19, op_ST_S = 20, op_STB_S = 21,
17 	op_STW_S = 22, op_Su5 = 23, op_SP = 24, op_GP = 25,
18 	op_Pcl = 26, op_MOV_S = 27, op_ADD_CMP = 28, op_BR_S = 29,
19 	op_B_S = 30, op_BL_S = 31
20 };
21 
22 enum flow {
23 	noflow,
24 	direct_jump,
25 	direct_call,
26 	indirect_jump,
27 	indirect_call,
28 	invalid_instr
29 };
30 
31 #define IS_BIT(word, n)		((word) & (1<<n))
32 #define BITS(word, s, e)	(((word) >> (s)) & (~((-2) << ((e) - (s)))))
33 
34 #define MAJOR_OPCODE(word)	(BITS((word), 27, 31))
35 #define MINOR_OPCODE(word)	(BITS((word), 16, 21))
36 #define FIELD_A(word)		(BITS((word), 0, 5))
37 #define FIELD_B(word)		((BITS((word), 12, 14)<<3) | \
38 				(BITS((word), 24, 26)))
39 #define FIELD_C(word)		(BITS((word), 6, 11))
40 #define FIELD_u6(word)		FIELDC(word)
41 #define FIELD_s12(word)		sign_extend(((BITS((word), 0, 5) << 6) | \
42 					BITS((word), 6, 11)), 12)
43 
44 /* note that for BL/BRcc these two macro's need another AND statement to mask
45  * out bit 1 (make the result a multiple of 4) */
46 #define FIELD_s9(word)		sign_extend(((BITS(word, 15, 15) << 8) | \
47 					BITS(word, 16, 23)), 9)
48 #define FIELD_s21(word)		sign_extend(((BITS(word, 6, 15) << 11) | \
49 					(BITS(word, 17, 26) << 1)), 12)
50 #define FIELD_s25(word)		sign_extend(((BITS(word, 0, 3) << 21) | \
51 					(BITS(word, 6, 15) << 11) | \
52 					(BITS(word, 17, 26) << 1)), 12)
53 
54 /* note: these operate on 16 bits! */
55 #define FIELD_S_A(word)		((BITS((word), 2, 2)<<3) | BITS((word), 0, 2))
56 #define FIELD_S_B(word)		((BITS((word), 10, 10)<<3) | \
57 				BITS((word), 8, 10))
58 #define FIELD_S_C(word)		((BITS((word), 7, 7)<<3) | BITS((word), 5, 7))
59 #define FIELD_S_H(word)		((BITS((word), 0, 2)<<3) | BITS((word), 5, 8))
60 #define FIELD_S_u5(word)	(BITS((word), 0, 4))
61 #define FIELD_S_u6(word)	(BITS((word), 0, 4) << 1)
62 #define FIELD_S_u7(word)	(BITS((word), 0, 4) << 2)
63 #define FIELD_S_u10(word)	(BITS((word), 0, 7) << 2)
64 #define FIELD_S_s7(word)	sign_extend(BITS((word), 0, 5) << 1, 9)
65 #define FIELD_S_s8(word)	sign_extend(BITS((word), 0, 7) << 1, 9)
66 #define FIELD_S_s9(word)	sign_extend(BITS((word), 0, 8), 9)
67 #define FIELD_S_s10(word)	sign_extend(BITS((word), 0, 8) << 1, 10)
68 #define FIELD_S_s11(word)	sign_extend(BITS((word), 0, 8) << 2, 11)
69 #define FIELD_S_s13(word)	sign_extend(BITS((word), 0, 10) << 2, 13)
70 
71 #define STATUS32_L		0x00000100
72 #define REG_LIMM		62
73 
74 struct disasm_state {
75 	/* generic info */
76 	unsigned long words[2];
77 	int instr_len;
78 	int major_opcode;
79 	/* info for branch/jump */
80 	int is_branch;
81 	int target;
82 	int delay_slot;
83 	enum flow flow;
84 	/* info for load/store */
85 	int src1, src2, src3, dest, wb_reg;
86 	int zz, aa, x, pref, di;
87 	int fault, write;
88 };
89 
sign_extend(int value,int bits)90 static inline int sign_extend(int value, int bits)
91 {
92 	if (IS_BIT(value, (bits - 1)))
93 		value |= (0xffffffff << bits);
94 
95 	return value;
96 }
97 
is_short_instr(unsigned long addr)98 static inline int is_short_instr(unsigned long addr)
99 {
100 	uint16_t word = *((uint16_t *)addr);
101 	int opcode = (word >> 11) & 0x1F;
102 	return (opcode >= 0x0B);
103 }
104 
105 void disasm_instr(unsigned long addr, struct disasm_state *state,
106 	int userspace, struct pt_regs *regs, struct callee_regs *cregs);
107 int disasm_next_pc(unsigned long pc, struct pt_regs *regs, struct callee_regs
108 	*cregs, unsigned long *fall_thru, unsigned long *target);
109 long get_reg(int reg, struct pt_regs *regs, struct callee_regs *cregs);
110 void set_reg(int reg, long val, struct pt_regs *regs,
111 		struct callee_regs *cregs);
112 
113 #endif	/* __ARC_DISASM_H__ */
114