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Refactor the memrw functions to reduce the redundancy. (#415)

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The impact is limited now, but will increase when adding support for more architectures and more bit widths.
This commit is contained in:
Lionel Debroux
2024-07-16 09:55:13 +02:00
committed by GitHub
parent fa583c906b
commit 8d966d98f4
11 changed files with 109 additions and 148 deletions
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88
system/memrw.h Normal file
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// SPDX-License-Identifier: GPL-2.0
#ifndef MEMRW_H
#define MEMRW_H
/**
* \file
*
* Provides some 32/64-bit memory access functions. These stop the compiler
* optimizing accesses which need to be ordered and atomic. Mostly used
* for accessing memory-mapped hardware registers.
*
*//*
* Copyright (C) 2021-2022 Martin Whitaker.
* Copyright (C) 2024 Lionel Debroux.
*/
#include <stdint.h>
#define __MEMRW_SUFFIX_32BIT "l"
#define __MEMRW_SUFFIX_64BIT "q"
#define __MEMRW_READ_INSTRUCTIONS(bitwidth) "mov" __MEMRW_SUFFIX_##bitwidth##BIT " %1, %0"
#define __MEMRW_WRITE_INSTRUCTIONS(bitwidth) "mov" __MEMRW_SUFFIX_##bitwidth##BIT " %1, %0"
#define __MEMRW_FLUSH_INSTRUCTIONS(bitwidth) "mov" __MEMRW_SUFFIX_##bitwidth##BIT " %1, %0; mov" __MEMRW_SUFFIX_##bitwidth##BIT " %0, %1"
#define __MEMRW_READ_FUNC(bitwidth) \
static inline uint##bitwidth##_t read##bitwidth(const volatile uint##bitwidth##_t *ptr) \
{ \
uint##bitwidth##_t val; \
__asm__ __volatile__( \
__MEMRW_READ_INSTRUCTIONS(bitwidth) \
: "=r" (val) \
: "m" (*ptr) \
: "memory" \
); \
return val; \
}
#define __MEMRW_WRITE_FUNC(bitwidth) \
static inline void write##bitwidth(const volatile uint##bitwidth##_t *ptr, uint##bitwidth##_t val) \
{ \
__asm__ __volatile__( \
__MEMRW_WRITE_INSTRUCTIONS(bitwidth) \
: \
: "m" (*ptr), \
"r" (val) \
: "memory" \
); \
}
#define __MEMRW_FLUSH_FUNC(bitwidth) \
static inline void flush##bitwidth(const volatile uint##bitwidth##_t *ptr, uint##bitwidth##_t val) \
{ \
__asm__ __volatile__( \
__MEMRW_FLUSH_INSTRUCTIONS(bitwidth) \
: \
: "m" (*ptr), \
"r" (val) \
: "memory" \
); \
}
/**
* Reads and returns the value stored in the 32-bit memory location pointed to by ptr.
*/
__MEMRW_READ_FUNC(32)
/**
* Reads and returns the value stored in the 64-bit memory location pointed to by ptr.
*/
__MEMRW_READ_FUNC(64)
/**
* Writes val to the 32-bit memory location pointed to by ptr.
*/
__MEMRW_WRITE_FUNC(32)
/**
* Writes val to the 64-bit memory location pointed to by ptr.
*/
__MEMRW_WRITE_FUNC(64)
/**
* Writes val to the 32-bit memory location pointed to by ptr. Only returns when the write is complete.
*/
__MEMRW_FLUSH_FUNC(32)
/**
* Writes val to the 64-bit memory location pointed to by ptr. Only returns when the write is complete.
*/
__MEMRW_FLUSH_FUNC(64)
#endif // MEMRW_H