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