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