1 /* SPDX-License-Identifier: GPL-2.0 */ 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 #ifndef CONFIG_CPU_ENDIAN_BE32 114 /* 115 * On BE32 systems, using 32-bit accesses to store Thumb instructions will not 116 * work in all cases, due to alignment constraints. For now, a correct 117 * version is not provided for BE32. 118 */ 119 #define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x) 120 #define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x) 121 #endif 122 123 #endif /* ! CONFIG_CPU_ENDIAN_BE8 */ 124 125 #define __mem_to_opcode_arm(x) __opcode_to_mem_arm(x) 126 #define __mem_to_opcode_thumb16(x) __opcode_to_mem_thumb16(x) 127 #ifndef CONFIG_CPU_ENDIAN_BE32 128 #define __mem_to_opcode_thumb32(x) __opcode_to_mem_thumb32(x) 129 #endif 130 131 /* Operations specific to Thumb opcodes */ 132 133 /* Instruction size checks: */ 134 #define __opcode_is_thumb32(x) ( \ 135 ((x) & 0xF8000000) == 0xE8000000 \ 136 || ((x) & 0xF0000000) == 0xF0000000 \ 137 ) 138 #define __opcode_is_thumb16(x) ( \ 139 ((x) & 0xFFFF0000) == 0 \ 140 && !(((x) & 0xF800) == 0xE800 || ((x) & 0xF000) == 0xF000) \ 141 ) 142 143 /* Operations to construct or split 32-bit Thumb instructions: */ 144 #define __opcode_thumb32_first(x) (___opcode_identity16((x) >> 16)) 145 #define __opcode_thumb32_second(x) (___opcode_identity16(x)) 146 #define __opcode_thumb32_compose(first, second) ( \ 147 (___opcode_identity32(___opcode_identity16(first)) << 16) \ 148 | ___opcode_identity32(___opcode_identity16(second)) \ 149 ) 150 #define ___asm_opcode_thumb32_first(x) (___asm_opcode_identity16((x) >> 16)) 151 #define ___asm_opcode_thumb32_second(x) (___asm_opcode_identity16(x)) 152 #define ___asm_opcode_thumb32_compose(first, second) ( \ 153 (___asm_opcode_identity32(___asm_opcode_identity16(first)) << 16) \ 154 | ___asm_opcode_identity32(___asm_opcode_identity16(second)) \ 155 ) 156 157 /* 158 * Opcode injection helpers 159 * 160 * In rare cases it is necessary to assemble an opcode which the 161 * assembler does not support directly, or which would normally be 162 * rejected because of the CFLAGS or AFLAGS used to build the affected 163 * file. 164 * 165 * Before using these macros, consider carefully whether it is feasible 166 * instead to change the build flags for your file, or whether it really 167 * makes sense to support old assembler versions when building that 168 * particular kernel feature. 169 * 170 * The macros defined here should only be used where there is no viable 171 * alternative. 172 * 173 * 174 * __inst_arm(x): emit the specified ARM opcode 175 * __inst_thumb16(x): emit the specified 16-bit Thumb opcode 176 * __inst_thumb32(x): emit the specified 32-bit Thumb opcode 177 * 178 * __inst_arm_thumb16(arm, thumb): emit either the specified arm or 179 * 16-bit Thumb opcode, depending on whether an ARM or Thumb-2 180 * kernel is being built 181 * 182 * __inst_arm_thumb32(arm, thumb): emit either the specified arm or 183 * 32-bit Thumb opcode, depending on whether an ARM or Thumb-2 184 * kernel is being built 185 * 186 * 187 * Note that using these macros directly is poor practice. Instead, you 188 * should use them to define human-readable wrapper macros to encode the 189 * instructions that you care about. In code which might run on ARMv7 or 190 * above, you can usually use the __inst_arm_thumb{16,32} macros to 191 * specify the ARM and Thumb alternatives at the same time. This ensures 192 * that the correct opcode gets emitted depending on the instruction set 193 * used for the kernel build. 194 * 195 * Look at opcodes-virt.h for an example of how to use these macros. 196 */ 197 #include <linux/stringify.h> 198 199 #define __inst_arm(x) ___inst_arm(___asm_opcode_to_mem_arm(x)) 200 #define __inst_thumb32(x) ___inst_thumb32( \ 201 ___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_first(x)), \ 202 ___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_second(x)) \ 203 ) 204 #define __inst_thumb16(x) ___inst_thumb16(___asm_opcode_to_mem_thumb16(x)) 205 206 #ifdef CONFIG_THUMB2_KERNEL 207 #define __inst_arm_thumb16(arm_opcode, thumb_opcode) \ 208 __inst_thumb16(thumb_opcode) 209 #define __inst_arm_thumb32(arm_opcode, thumb_opcode) \ 210 __inst_thumb32(thumb_opcode) 211 #else 212 #define __inst_arm_thumb16(arm_opcode, thumb_opcode) __inst_arm(arm_opcode) 213 #define __inst_arm_thumb32(arm_opcode, thumb_opcode) __inst_arm(arm_opcode) 214 #endif 215 216 /* Helpers for the helpers. Don't use these directly. */ 217 #ifdef __ASSEMBLY__ 218 #define ___inst_arm(x) .long x 219 #define ___inst_thumb16(x) .short x 220 #define ___inst_thumb32(first, second) .short first, second 221 #else 222 #define ___inst_arm(x) ".long " __stringify(x) "\n\t" 223 #define ___inst_thumb16(x) ".short " __stringify(x) "\n\t" 224 #define ___inst_thumb32(first, second) \ 225 ".short " __stringify(first) ", " __stringify(second) "\n\t" 226 #endif 227 228 #endif /* __ASM_ARM_OPCODES_H */ 229