/* Copyright 2018 SiFive, Inc */
/* SPDX-License-Identifier: Apache-2.0 */

#ifndef METAL__IO_H
#define METAL__IO_H

/* This macro enforces that the compiler will not elide the given access. */
#define __METAL_ACCESS_ONCE(x) (*(typeof(*x) volatile *)(x))

/* Allows users to specify arbitrary fences. */
#define __METAL_IO_FENCE(pred, succ) __asm__ volatile ("fence " #pred "," #succ ::: "memory");

/* Types that explicitly describe an address as being used for memory-mapped
 * IO.  These should only be accessed via __METAL_ACCESS_ONCE. */
typedef unsigned char  __metal_io_u8;
typedef unsigned short __metal_io_u16;
typedef unsigned int   __metal_io_u32;
#if __riscv_xlen >= 64
typedef unsigned long  __metal_io_u64;
#endif

#endif