1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*
* arch/arm/include/asm/opcodes.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARM_OPCODES_H
#define __ASM_ARM_OPCODES_H
#ifndef __ASSEMBLY__
extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
#endif
#define ARM_OPCODE_CONDTEST_FAIL 0
#define ARM_OPCODE_CONDTEST_PASS 1
#define ARM_OPCODE_CONDTEST_UNCOND 2
/*
* Assembler opcode byteswap helpers.
* These are only intended for use by this header: don't use them directly,
* because they will be suboptimal in most cases.
*/
#define ___asm_opcode_swab32(x) ( \
(((x) << 24) & 0xFF000000) \
| (((x) << 8) & 0x00FF0000) \
| (((x) >> 8) & 0x0000FF00) \
| (((x) >> 24) & 0x000000FF) \
)
#define ___asm_opcode_swab16(x) ( \
(((x) << 8) & 0xFF00) \
| (((x) >> 8) & 0x00FF) \
)
#define ___asm_opcode_swahb32(x) ( \
(((x) << 8) & 0xFF00FF00) \
| (((x) >> 8) & 0x00FF00FF) \
)
#define ___asm_opcode_swahw32(x) ( \
(((x) << 16) & 0xFFFF0000) \
| (((x) >> 16) & 0x0000FFFF) \
)
#define ___asm_opcode_identity32(x) ((x) & 0xFFFFFFFF)
#define ___asm_opcode_identity16(x) ((x) & 0xFFFF)
/*
* Opcode byteswap helpers
*
* These macros help with converting instructions between a canonical integer
* format and in-memory representation, in an endianness-agnostic manner.
*
* __mem_to_opcode_*() convert from in-memory representation to canonical form.
* __opcode_to_mem_*() convert from canonical form to in-memory representation.
*
*
* Canonical instruction representation:
*
* ARM: 0xKKLLMMNN
* Thumb 16-bit: 0x0000KKLL, where KK < 0xE8
* Thumb 32-bit: 0xKKLLMMNN, where KK >= 0xE8
*
* There is no way to distinguish an ARM instruction in canonical representation
* from a Thumb instruction (just as these cannot be distinguished in memory).
* Where this distinction is important, it needs to be tracked separately.
*
* Note that values in the range 0x0000E800..0xE7FFFFFF intentionally do not
* represent any valid Thumb-2 instruction. For this range,
* __opcode_is_thumb32() and __opcode_is_thumb16() will both be false.
*
* The ___asm variants are intended only for use by this header, in situations
* involving inline assembler. For .S files, the normal __opcode_*() macros
* should do the right thing.
*/
#ifdef __ASSEMBLY__
#define ___opcode_swab32(x) ___asm_opcode_swab32(x)
#define ___opcode_swab16(x) ___asm_opcode_swab16(x)
#define ___opcode_swahb32(x) ___asm_opcode_swahb32(x)
#define ___opcode_swahw32(x) ___asm_opcode_swahw32(x)
#define ___opcode_identity32(x) ___asm_opcode_identity32(x)
#define ___opcode_identity16(x) ___asm_opcode_identity16(x)
#else /* ! __ASSEMBLY__ */
#include <linux/types.h>
#include <linux/swab.h>
#define ___opcode_swab32(x) swab32(x)
#define ___opcode_swab16(x) swab16(x)
#define ___opcode_swahb32(x) swahb32(x)
#define ___opcode_swahw32(x) swahw32(x)
#define ___opcode_identity32(x) ((u32)(x))
#define ___opcode_identity16(x) ((u16)(x))
#endif /* ! __ASSEMBLY__ */
#ifdef CONFIG_CPU_ENDIAN_BE8
#define __opcode_to_mem_arm(x) ___opcode_swab32(x)
#define __opcode_to_mem_thumb16(x) ___opcode_swab16(x)
#define __opcode_to_mem_thumb32(x) ___opcode_swahb32(x)
#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_swab32(x)
#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_swab16(x)
#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahb32(x)
#else /* ! CONFIG_CPU_ENDIAN_BE8 */
#define __opcode_to_mem_arm(x) ___opcode_identity32(x)
#define __opcode_to_mem_thumb16(x) ___opcode_identity16(x)
#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_identity32(x)
#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_identity16(x)
#ifndef CONFIG_CPU_ENDIAN_BE32
/*
* On BE32 systems, using 32-bit accesses to store Thumb instructions will not
* work in all cases, due to alignment constraints. For now, a correct
* version is not provided for BE32.
*/
#define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x)
#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x)
#endif
#endif /* ! CONFIG_CPU_ENDIAN_BE8 */
#define __mem_to_opcode_arm(x) __opcode_to_mem_arm(x)
#define __mem_to_opcode_thumb16(x) __opcode_to_mem_thumb16(x)
#ifndef CONFIG_CPU_ENDIAN_BE32
#define __mem_to_opcode_thumb32(x) __opcode_to_mem_thumb32(x)
#endif
/* Operations specific to Thumb opcodes */
/* Instruction size checks: */
#define __opcode_is_thumb32(x) ( \
((x) & 0xF8000000) == 0xE8000000 \
|| ((x) & 0xF0000000) == 0xF0000000 \
)
#define __opcode_is_thumb16(x) ( \
((x) & 0xFFFF0000) == 0 \
&& !(((x) & 0xF800) == 0xE800 || ((x) & 0xF000) == 0xF000) \
)
/* Operations to construct or split 32-bit Thumb instructions: */
#define __opcode_thumb32_first(x) (___opcode_identity16((x) >> 16))
#define __opcode_thumb32_second(x) (___opcode_identity16(x))
#define __opcode_thumb32_compose(first, second) ( \
(___opcode_identity32(___opcode_identity16(first)) << 16) \
| ___opcode_identity32(___opcode_identity16(second)) \
)
#define ___asm_opcode_thumb32_first(x) (___asm_opcode_identity16((x) >> 16))
#define ___asm_opcode_thumb32_second(x) (___asm_opcode_identity16(x))
#define ___asm_opcode_thumb32_compose(first, second) ( \
(___asm_opcode_identity32(___asm_opcode_identity16(first)) << 16) \
| ___asm_opcode_identity32(___asm_opcode_identity16(second)) \
)
/*
* Opcode injection helpers
*
* In rare cases it is necessary to assemble an opcode which the
* assembler does not support directly, or which would normally be
* rejected because of the CFLAGS or AFLAGS used to build the affected
* file.
*
* Before using these macros, consider carefully whether it is feasible
* instead to change the build flags for your file, or whether it really
* makes sense to support old assembler versions when building that
* particular kernel feature.
*
* The macros defined here should only be used where there is no viable
* alternative.
*
*
* __inst_arm(x): emit the specified ARM opcode
* __inst_thumb16(x): emit the specified 16-bit Thumb opcode
* __inst_thumb32(x): emit the specified 32-bit Thumb opcode
*
* __inst_arm_thumb16(arm, thumb): emit either the specified arm or
* 16-bit Thumb opcode, depending on whether an ARM or Thumb-2
* kernel is being built
*
* __inst_arm_thumb32(arm, thumb): emit either the specified arm or
* 32-bit Thumb opcode, depending on whether an ARM or Thumb-2
* kernel is being built
*
*
* Note that using these macros directly is poor practice. Instead, you
* should use them to define human-readable wrapper macros to encode the
* instructions that you care about. In code which might run on ARMv7 or
* above, you can usually use the __inst_arm_thumb{16,32} macros to
* specify the ARM and Thumb alternatives at the same time. This ensures
* that the correct opcode gets emitted depending on the instruction set
* used for the kernel build.
*
* Look at opcodes-virt.h for an example of how to use these macros.
*/
#include <linux/stringify.h>
#define __inst_arm(x) ___inst_arm(___asm_opcode_to_mem_arm(x))
#define __inst_thumb32(x) ___inst_thumb32( \
___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_first(x)), \
___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_second(x)) \
)
#define __inst_thumb16(x) ___inst_thumb16(___asm_opcode_to_mem_thumb16(x))
#ifdef CONFIG_THUMB2_KERNEL
#define __inst_arm_thumb16(arm_opcode, thumb_opcode) \
__inst_thumb16(thumb_opcode)
#define __inst_arm_thumb32(arm_opcode, thumb_opcode) \
__inst_thumb32(thumb_opcode)
#else
#define __inst_arm_thumb16(arm_opcode, thumb_opcode) __inst_arm(arm_opcode)
#define __inst_arm_thumb32(arm_opcode, thumb_opcode) __inst_arm(arm_opcode)
#endif
/* Helpers for the helpers. Don't use these directly. */
#ifdef __ASSEMBLY__
#define ___inst_arm(x) .long x
#define ___inst_thumb16(x) .short x
#define ___inst_thumb32(first, second) .short first, second
#else
#define ___inst_arm(x) ".long " __stringify(x) "\n\t"
#define ___inst_thumb16(x) ".short " __stringify(x) "\n\t"
#define ___inst_thumb32(first, second) \
".short " __stringify(first) ", " __stringify(second) "\n\t"
#endif
#endif /* __ASM_ARM_OPCODES_H */
|
