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