xref: /openbmc/linux/arch/arc/include/asm/disasm.h (revision e2c75e76)
1 /*
2  * several functions that help interpret ARC instructions
3  * used for unaligned accesses, kprobes and kgdb
4  *
5  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #ifndef __ARC_DISASM_H__
13 #define __ARC_DISASM_H__
14 
15 enum {
16 	op_Bcc = 0, op_BLcc = 1, op_LD = 2, op_ST = 3, op_MAJOR_4 = 4,
17 	op_MAJOR_5 = 5, op_LD_ADD = 12, op_ADD_SUB_SHIFT = 13,
18 	op_ADD_MOV_CMP = 14, op_S = 15, op_LD_S = 16, op_LDB_S = 17,
19 	op_LDW_S = 18, op_LDWX_S = 19, op_ST_S = 20, op_STB_S = 21,
20 	op_STW_S = 22, op_Su5 = 23, op_SP = 24, op_GP = 25,
21 	op_Pcl = 26, op_MOV_S = 27, op_ADD_CMP = 28, op_BR_S = 29,
22 	op_B_S = 30, op_BL_S = 31
23 };
24 
25 enum flow {
26 	noflow,
27 	direct_jump,
28 	direct_call,
29 	indirect_jump,
30 	indirect_call,
31 	invalid_instr
32 };
33 
34 #define IS_BIT(word, n)		((word) & (1<<n))
35 #define BITS(word, s, e)	(((word) >> (s)) & (~((-2) << ((e) - (s)))))
36 
37 #define MAJOR_OPCODE(word)	(BITS((word), 27, 31))
38 #define MINOR_OPCODE(word)	(BITS((word), 16, 21))
39 #define FIELD_A(word)		(BITS((word), 0, 5))
40 #define FIELD_B(word)		((BITS((word), 12, 14)<<3) | \
41 				(BITS((word), 24, 26)))
42 #define FIELD_C(word)		(BITS((word), 6, 11))
43 #define FIELD_u6(word)		FIELDC(word)
44 #define FIELD_s12(word)		sign_extend(((BITS((word), 0, 5) << 6) | \
45 					BITS((word), 6, 11)), 12)
46 
47 /* note that for BL/BRcc these two macro's need another AND statement to mask
48  * out bit 1 (make the result a multiple of 4) */
49 #define FIELD_s9(word)		sign_extend(((BITS(word, 15, 15) << 8) | \
50 					BITS(word, 16, 23)), 9)
51 #define FIELD_s21(word)		sign_extend(((BITS(word, 6, 15) << 11) | \
52 					(BITS(word, 17, 26) << 1)), 12)
53 #define FIELD_s25(word)		sign_extend(((BITS(word, 0, 3) << 21) | \
54 					(BITS(word, 6, 15) << 11) | \
55 					(BITS(word, 17, 26) << 1)), 12)
56 
57 /* note: these operate on 16 bits! */
58 #define FIELD_S_A(word)		((BITS((word), 2, 2)<<3) | BITS((word), 0, 2))
59 #define FIELD_S_B(word)		((BITS((word), 10, 10)<<3) | \
60 				BITS((word), 8, 10))
61 #define FIELD_S_C(word)		((BITS((word), 7, 7)<<3) | BITS((word), 5, 7))
62 #define FIELD_S_H(word)		((BITS((word), 0, 2)<<3) | BITS((word), 5, 8))
63 #define FIELD_S_u5(word)	(BITS((word), 0, 4))
64 #define FIELD_S_u6(word)	(BITS((word), 0, 4) << 1)
65 #define FIELD_S_u7(word)	(BITS((word), 0, 4) << 2)
66 #define FIELD_S_u10(word)	(BITS((word), 0, 7) << 2)
67 #define FIELD_S_s7(word)	sign_extend(BITS((word), 0, 5) << 1, 9)
68 #define FIELD_S_s8(word)	sign_extend(BITS((word), 0, 7) << 1, 9)
69 #define FIELD_S_s9(word)	sign_extend(BITS((word), 0, 8), 9)
70 #define FIELD_S_s10(word)	sign_extend(BITS((word), 0, 8) << 1, 10)
71 #define FIELD_S_s11(word)	sign_extend(BITS((word), 0, 8) << 2, 11)
72 #define FIELD_S_s13(word)	sign_extend(BITS((word), 0, 10) << 2, 13)
73 
74 #define STATUS32_L		0x00000100
75 #define REG_LIMM		62
76 
77 struct disasm_state {
78 	/* generic info */
79 	unsigned long words[2];
80 	int instr_len;
81 	int major_opcode;
82 	/* info for branch/jump */
83 	int is_branch;
84 	int target;
85 	int delay_slot;
86 	enum flow flow;
87 	/* info for load/store */
88 	int src1, src2, src3, dest, wb_reg;
89 	int zz, aa, x, pref, di;
90 	int fault, write;
91 };
92 
93 static inline int sign_extend(int value, int bits)
94 {
95 	if (IS_BIT(value, (bits - 1)))
96 		value |= (0xffffffff << bits);
97 
98 	return value;
99 }
100 
101 static inline int is_short_instr(unsigned long addr)
102 {
103 	uint16_t word = *((uint16_t *)addr);
104 	int opcode = (word >> 11) & 0x1F;
105 	return (opcode >= 0x0B);
106 }
107 
108 void disasm_instr(unsigned long addr, struct disasm_state *state,
109 	int userspace, struct pt_regs *regs, struct callee_regs *cregs);
110 int disasm_next_pc(unsigned long pc, struct pt_regs *regs, struct callee_regs
111 	*cregs, unsigned long *fall_thru, unsigned long *target);
112 long get_reg(int reg, struct pt_regs *regs, struct callee_regs *cregs);
113 void set_reg(int reg, long val, struct pt_regs *regs,
114 		struct callee_regs *cregs);
115 
116 #endif	/* __ARC_DISASM_H__ */
117