- 根目录:
- arch
- arm
- include
- asm
- opcodes.h
/*
* arch/arm/include/asm/opcodes.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARM_OPCODES_H
#define __ASM_ARM_OPCODES_H
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
#endif
#define ARM_OPCODE_CONDTEST_FAIL 0
#define ARM_OPCODE_CONDTEST_PASS 1
#define ARM_OPCODE_CONDTEST_UNCOND 2
/*
* Assembler opcode byteswap helpers.
* These are only intended for use by this header: don't use them directly,
* because they will be suboptimal in most cases.
*/
#define ___asm_opcode_swab32(x) ( \
(((x) << 24) & 0xFF000000) \
| (((x) << 8) & 0x00FF0000) \
| (((x) >> 8) & 0x0000FF00) \
| (((x) >> 24) & 0x000000FF) \
)
#define ___asm_opcode_swab16(x) ( \
(((x) << 8) & 0xFF00) \
| (((x) >> 8) & 0x00FF) \
)
#define ___asm_opcode_swahb32(x) ( \
(((x) << 8) & 0xFF00FF00) \
| (((x) >> 8) & 0x00FF00FF) \
)
#define ___asm_opcode_swahw32(x) ( \
(((x) << 16) & 0xFFFF0000) \
| (((x) >> 16) & 0x0000FFFF) \
)
#define ___asm_opcode_identity32(x) ((x) & 0xFFFFFFFF)
#define ___asm_opcode_identity16(x) ((x) & 0xFFFF)
/*
* Opcode byteswap helpers
*
* These macros help with converting instructions between a canonical integer
* format and in-memory representation, in an endianness-agnostic manner.
*
* __mem_to_opcode_*() convert from in-memory representation to canonical form.
* __opcode_to_mem_*() convert from canonical form to in-memory representation.
*
*
* Canonical instruction representation:
*
* ARM: 0xKKLLMMNN
* Thumb 16-bit: 0x0000KKLL, where KK < 0xE8
* Thumb 32-bit: 0xKKLLMMNN, where KK >= 0xE8
*
* There is no way to distinguish an ARM instruction in canonical representation
* from a Thumb instruction (just as these cannot be distinguished in memory).
* Where this distinction is important, it needs to be tracked separately.
*
* Note that values in the range 0x0000E800..0xE7FFFFFF intentionally do not
* represent any valid Thumb-2 instruction. For this range,
* __opcode_is_thumb32() and __opcode_is_thumb16() will both be false.
*
* The ___asm variants are intended only for use by this header, in situations
* involving inline assembler. For .S files, the normal __opcode_*() macros
* should do the right thing.
*/
#ifdef __ASSEMBLY__
#define ___opcode_swab32(x) ___asm_opcode_swab32(x)
#define ___opcode_swab16(x) ___asm_opcode_swab16(x)
#define ___opcode_swahb32(x) ___asm_opcode_swahb32(x)
#define ___opcode_swahw32(x) ___asm_opcode_swahw32(x)
#define ___opcode_identity32(x) ___asm_opcode_identity32(x)
#define ___opcode_identity16(x) ___asm_opcode_identity16(x)
#else /* ! __ASSEMBLY__ */
#include <linux/types.h>
#include <linux/swab.h>
#define ___opcode_swab32(x) swab32(x)
#define ___opcode_swab16(x) swab16(x)
#define ___opcode_swahb32(x) swahb32(x)
#define ___opcode_swahw32(x) swahw32(x)
#define ___opcode_identity32(x) ((u32)(x))
#define ___opcode_identity16(x) ((u16)(x))
#endif /* ! __ASSEMBLY__ */
#ifdef CONFIG_CPU_ENDIAN_BE8
#define __opcode_to_mem_arm(x) ___opcode_swab32(x)
#define __opcode_to_mem_thumb16(x) ___opcode_swab16(x)
#define __opcode_to_mem_thumb32(x) ___opcode_swahb32(x)
#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_swab32(x)
#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_swab16(x)
#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahb32(x)
#else /* ! CONFIG_CPU_ENDIAN_BE8 */
#define __opcode_to_mem_arm(x) ___opcode_identity32(x)
#define __opcode_to_mem_thumb16(x) ___opcode_identity16(x)
#define ___asm_opcode_to_mem_arm(x) ___asm_opcode_identity32(x)
#define ___asm_opcode_to_mem_thumb16(x) ___asm_opcode_identity16(x)
#ifndef CONFIG_CPU_ENDIAN_BE32
/*
* On BE32 systems, using 32-bit accesses to store Thumb instructions will not
* work in all cases, due to alignment constraints. For now, a correct
* version is not provided for BE32.
*/
#define __opcode_to_mem_thumb32(x) ___opcode_swahw32(x)
#define ___asm_opcode_to_mem_thumb32(x) ___asm_opcode_swahw32(x)
#endif
#endif /* ! CONFIG_CPU_ENDIAN_BE8 */
#define __mem_to_opcode_arm(x) __opcode_to_mem_arm(x)
#define __mem_to_opcode_thumb16(x) __opcode_to_mem_thumb16(x)
#ifndef CONFIG_CPU_ENDIAN_BE32
#define __mem_to_opcode_thumb32(x) __opcode_to_mem_thumb32(x)
#endif
/* Operations specific to Thumb opcodes */
/* Instruction size checks: */
#define __opcode_is_thumb32(x) ( \
((x) & 0xF8000000) == 0xE8000000 \
|| ((x) & 0xF0000000) == 0xF0000000 \
)
#define __opcode_is_thumb16(x) ( \
((x) & 0xFFFF0000) == 0 \
&& !(((x) & 0xF800) == 0xE800 || ((x) & 0xF000) == 0xF000) \
)
/* Operations to construct or split 32-bit Thumb instructions: */
#define __opcode_thumb32_first(x) (___opcode_identity16((x) >> 16))
#define __opcode_thumb32_second(x) (___opcode_identity16(x))
#define __opcode_thumb32_compose(first, second) ( \
(___opcode_identity32(___opcode_identity16(first)) << 16) \
| ___opcode_identity32(___opcode_identity16(second)) \
)
#define ___asm_opcode_thumb32_first(x) (___asm_opcode_identity16((x) >> 16))
#define ___asm_opcode_thumb32_second(x) (___asm_opcode_identity16(x))
#define ___asm_opcode_thumb32_compose(first, second) ( \
(___asm_opcode_identity32(___asm_opcode_identity16(first)) << 16) \
| ___asm_opcode_identity32(___asm_opcode_identity16(second)) \
)
/*
* Opcode injection helpers
*
* In rare cases it is necessary to assemble an opcode which the
* assembler does not support directly, or which would normally be
* rejected because of the CFLAGS or AFLAGS used to build the affected
* file.
*
* Before using these macros, consider carefully whether it is feasible
* instead to change the build flags for your file, or whether it really
* makes sense to support old assembler versions when building that
* particular kernel feature.
*
* The macros defined here should only be used where there is no viable
* alternative.
*
*
* __inst_arm(x): emit the specified ARM opcode
* __inst_thumb16(x): emit the specified 16-bit Thumb opcode
* __inst_thumb32(x): emit the specified 32-bit Thumb opcode
*
* __inst_arm_thumb16(arm, thumb): emit either the specified arm or
* 16-bit Thumb opcode, depending on whether an ARM or Thumb-2
* kernel is being built
*
* __inst_arm_thumb32(arm, thumb): emit either the specified arm or
* 32-bit Thumb opcode, depending on whether an ARM or Thumb-2
* kernel is being built
*
*
* Note that using these macros directly is poor practice. Instead, you
* should use them to define human-readable wrapper macros to encode the
* instructions that you care about. In code which might run on ARMv7 or
* above, you can usually use the __inst_arm_thumb{16,32} macros to
* specify the ARM and Thumb alternatives at the same time. This ensures
* that the correct opcode gets emitted depending on the instruction set
* used for the kernel build.
*
* Look at opcodes-virt.h for an example of how to use these macros.
*/
#include <linux/stringify.h>
#define __inst_arm(x) ___inst_arm(___asm_opcode_to_mem_arm(x))
#define __inst_thumb32(x) ___inst_thumb32( \
___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_first(x)), \
___asm_opcode_to_mem_thumb16(___asm_opcode_thumb32_second(x)) \
)
#define __inst_thumb16(x) ___inst_thumb16(___asm_opcode_to_mem_thumb16(x))
#ifdef CONFIG_THUMB2_KERNEL
#define __inst_arm_thumb16(arm_opcode, thumb_opcode) \
__inst_thumb16(thumb_opcode)
#define __inst_arm_thumb32(arm_opcode, thumb_opcode) \
__inst_thumb32(thumb_opcode)
#else
#define __inst_arm_thumb16(arm_opcode, thumb_opcode) __inst_arm(arm_opcode)
#define __inst_arm_thumb32(arm_opcode, thumb_opcode) __inst_arm(arm_opcode)
#endif
/* Helpers for the helpers. Don't use these directly. */
#ifdef __ASSEMBLY__
#define ___inst_arm(x) .long x
#define ___inst_thumb16(x) .short x
#define ___inst_thumb32(first, second) .short first, second
#else
#define ___inst_arm(x) ".long " __stringify(x) "\n\t"
#define ___inst_thumb16(x) ".short " __stringify(x) "\n\t"
#define ___inst_thumb32(first, second) \
".short " __stringify(first) ", " __stringify(second) "\n\t"
#endif
#endif /* __ASM_ARM_OPCODES_H */