1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * arch/arm/include/asm/opcodes.h
4 */
5
6 #ifndef __ASM_ARM_OPCODES_H
7 #define __ASM_ARM_OPCODES_H
8
9 #ifndef __ASSEMBLY__
10 #include <linux/linkage.h>
11 extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
12 #endif
13
14 #define ARM_OPCODE_CONDTEST_FAIL 0
15 #define ARM_OPCODE_CONDTEST_PASS 1
16 #define ARM_OPCODE_CONDTEST_UNCOND 2
17
18
19 /*
20 * Assembler opcode byteswap helpers.
21 * These are only intended for use by this header: don't use them directly,
22 * because they will be suboptimal in most cases.
23 */
24 #define ___asm_opcode_swab32(x) ( \
25 (((x) << 24) & 0xFF000000) \
26 | (((x) << 8) & 0x00FF0000) \
27 | (((x) >> 8) & 0x0000FF00) \
28 | (((x) >> 24) & 0x000000FF) \
29 )
30 #define ___asm_opcode_swab16(x) ( \
31 (((x) << 8) & 0xFF00) \
32 | (((x) >> 8) & 0x00FF) \
33 )
34 #define ___asm_opcode_swahb32(x) ( \
35 (((x) << 8) & 0xFF00FF00) \
36 | (((x) >> 8) & 0x00FF00FF) \
37 )
38 #define ___asm_opcode_swahw32(x) ( \
39 (((x) << 16) & 0xFFFF0000) \
40 | (((x) >> 16) & 0x0000FFFF) \
41 )
42 #define ___asm_opcode_identity32(x) ((x) & 0xFFFFFFFF)
43 #define ___asm_opcode_identity16(x) ((x) & 0xFFFF)
44
45
46 /*
47 * Opcode byteswap helpers
48 *
49 * These macros help with converting instructions between a canonical integer
50 * format and in-memory representation, in an endianness-agnostic manner.
51 *
52 * __mem_to_opcode_*() convert from in-memory representation to canonical form.
53 * __opcode_to_mem_*() convert from canonical form to in-memory representation.
54 *
55 *
56 * Canonical instruction representation:
57 *
58 * ARM: 0xKKLLMMNN
59 * Thumb 16-bit: 0x0000KKLL, where KK < 0xE8
60 * Thumb 32-bit: 0xKKLLMMNN, where KK >= 0xE8
61 *
62 * There is no way to distinguish an ARM instruction in canonical representation
63 * from a Thumb instruction (just as these cannot be distinguished in memory).
64 * Where this distinction is important, it needs to be tracked separately.
65 *
66 * Note that values in the range 0x0000E800..0xE7FFFFFF intentionally do not
67 * represent any valid Thumb-2 instruction. For this range,
68 * __opcode_is_thumb32() and __opcode_is_thumb16() will both be false.
69 *
70 * The ___asm variants are intended only for use by this header, in situations
71 * involving inline assembler. For .S files, the normal __opcode_*() macros
72 * should do the right thing.
73 */
74 #ifdef __ASSEMBLY__
75
76 #define ___opcode_swab32(x) ___asm_opcode_swab32(x)
77 #define ___opcode_swab16(x) ___asm_opcode_swab16(x)
78 #define ___opcode_swahb32(x) ___asm_opcode_swahb32(x)
79 #define ___opcode_swahw32(x) ___asm_opcode_swahw32(x)
80 #define ___opcode_identity32(x) ___asm_opcode_identity32(x)
81 #define ___opcode_identity16(x) ___asm_opcode_identity16(x)
82
83 #else /* ! __ASSEMBLY__ */
84
85 #include <linux/types.h>
86 #include <linux/swab.h>
87
88 #define ___opcode_swab32(x) swab32(x)
89 #define ___opcode_swab16(x) swab16(x)
90 #define ___opcode_swahb32(x) swahb32(x)
91 #define ___opcode_swahw32(x) swahw32(x)
92 #define ___opcode_identity32(x) ((u32)(x))
93 #define ___opcode_identity16(x) ((u16)(x))
94
95 #endif /* ! __ASSEMBLY__ */
96
97
98 #ifdef CONFIG_CPU_ENDIAN_BE8
99
100 #define __opcode_to_mem_arm(x) ___opcode_swab32(x)
101 #define __opcode_to_mem_thumb16(x) ___opcode_swab16(x)
102 #define __opcode_to_mem_thumb32(x) ___opcode_swahb32(x)
103 #define ___asm_opcode_to_mem_arm(x) ___asm_opcode_swab32(x)
104 #define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_swab16(x)
105 #define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahb32(x)
106
107 #else /* ! CONFIG_CPU_ENDIAN_BE8 */
108
109 #define __opcode_to_mem_arm(x) ___opcode_identity32(x)
110 #define __opcode_to_mem_thumb16(x) ___opcode_identity16(x)
111 #define ___asm_opcode_to_mem_arm(x) ___asm_opcode_identity32(x)
112 #define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_identity16(x)
113 #ifdef CONFIG_CPU_ENDIAN_BE32
114 #ifndef __ASSEMBLY__
115 /*
116 * On BE32 systems, using 32-bit accesses to store Thumb instructions will not
117 * work in all cases, due to alignment constraints. For now, a correct
118 * version is not provided for BE32, but the prototype needs to be there
119 * to compile patch.c.
120 */
121 extern __u32 __opcode_to_mem_thumb32(__u32);
122 #endif
123 #else
124 #define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x)
125 #define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x)
126 #endif
127
128 #endif /* ! CONFIG_CPU_ENDIAN_BE8 */
129
130 #define __mem_to_opcode_arm(x) __opcode_to_mem_arm(x)
131 #define __mem_to_opcode_thumb16(x) __opcode_to_mem_thumb16(x)
132 #ifndef CONFIG_CPU_ENDIAN_BE32
133 #define __mem_to_opcode_thumb32(x) __opcode_to_mem_thumb32(x)
134 #endif
135
136 /* Operations specific to Thumb opcodes */
137
138 /* Instruction size checks: */
139 #define __opcode_is_thumb32(x) ( \
140 ((x) & 0xF8000000) == 0xE8000000 \
141 || ((x) & 0xF0000000) == 0xF0000000 \
142 )
143 #define __opcode_is_thumb16(x) ( \
144 ((x) & 0xFFFF0000) == 0 \
145 && !(((x) & 0xF800) == 0xE800 || ((x) & 0xF000) == 0xF000) \
146 )
147
148 /* Operations to construct or split 32-bit Thumb instructions: */
149 #define __opcode_thumb32_first(x) (___opcode_identity16((x) >> 16))
150 #define __opcode_thumb32_second(x) (___opcode_identity16(x))
151 #define __opcode_thumb32_compose(first, second) ( \
152 (___opcode_identity32(___opcode_identity16(first)) << 16) \
153 | ___opcode_identity32(___opcode_identity16(second)) \
154 )
155 #define ___asm_opcode_thumb32_first(x) (___asm_opcode_identity16((x) >> 16))
156 #define ___asm_opcode_thumb32_second(x) (___asm_opcode_identity16(x))
157 #define ___asm_opcode_thumb32_compose(first, second) ( \
158 (___asm_opcode_identity32(___asm_opcode_identity16(first)) << 16) \
159 | ___asm_opcode_identity32(___asm_opcode_identity16(second)) \
160 )
161
162 /*
163 * Opcode injection helpers
164 *
165 * In rare cases it is necessary to assemble an opcode which the
166 * assembler does not support directly, or which would normally be
167 * rejected because of the CFLAGS or AFLAGS used to build the affected
168 * file.
169 *
170 * Before using these macros, consider carefully whether it is feasible
171 * instead to change the build flags for your file, or whether it really
172 * makes sense to support old assembler versions when building that
173 * particular kernel feature.
174 *
175 * The macros defined here should only be used where there is no viable
176 * alternative.
177 *
178 *
179 * __inst_arm(x): emit the specified ARM opcode
180 * __inst_thumb16(x): emit the specified 16-bit Thumb opcode
181 * __inst_thumb32(x): emit the specified 32-bit Thumb opcode
182 *
183 * __inst_arm_thumb16(arm, thumb): emit either the specified arm or
184 * 16-bit Thumb opcode, depending on whether an ARM or Thumb-2
185 * kernel is being built
186 *
187 * __inst_arm_thumb32(arm, thumb): emit either the specified arm or
188 * 32-bit Thumb opcode, depending on whether an ARM or Thumb-2
189 * kernel is being built
190 *
191 *
192 * Note that using these macros directly is poor practice. Instead, you
193 * should use them to define human-readable wrapper macros to encode the
194 * instructions that you care about. In code which might run on ARMv7 or
195 * above, you can usually use the __inst_arm_thumb{16,32} macros to
196 * specify the ARM and Thumb alternatives at the same time. This ensures
197 * that the correct opcode gets emitted depending on the instruction set
198 * used for the kernel build.
199 *
200 * Look at opcodes-virt.h for an example of how to use these macros.
201 */
202 #include <linux/stringify.h>
203
204 #define __inst_arm(x) ___inst_arm(___asm_opcode_to_mem_arm(x))
205 #define __inst_thumb32(x) ___inst_thumb32( \
206 ___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_first(x)), \
207 ___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_second(x)) \
208 )
209 #define __inst_thumb16(x) ___inst_thumb16(___asm_opcode_to_mem_thumb16(x))
210
211 #ifdef CONFIG_THUMB2_KERNEL
212 #define __inst_arm_thumb16(arm_opcode, thumb_opcode) \
213 __inst_thumb16(thumb_opcode)
214 #define __inst_arm_thumb32(arm_opcode, thumb_opcode) \
215 __inst_thumb32(thumb_opcode)
216 #else
217 #define __inst_arm_thumb16(arm_opcode, thumb_opcode) __inst_arm(arm_opcode)
218 #define __inst_arm_thumb32(arm_opcode, thumb_opcode) __inst_arm(arm_opcode)
219 #endif
220
221 /* Helpers for the helpers. Don't use these directly. */
222 #ifdef __ASSEMBLY__
223 #define ___inst_arm(x) .long x
224 #define ___inst_thumb16(x) .short x
225 #define ___inst_thumb32(first, second) .short first, second
226 #else
227 #define ___inst_arm(x) ".long " __stringify(x) "\n\t"
228 #define ___inst_thumb16(x) ".short " __stringify(x) "\n\t"
229 #define ___inst_thumb32(first, second) \
230 ".short " __stringify(first) ", " __stringify(second) "\n\t"
231 #endif
232
233 #endif /* __ASM_ARM_OPCODES_H */
234
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.