opcodes.h (8255B)
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> 11extern 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 */ 121extern __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 */