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> 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#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