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 extern 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 */ 231