clint.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright (C) 2020 Google, Inc
 4 */
 5
 6#ifndef _ASM_RISCV_CLINT_H
 7#define _ASM_RISCV_CLINT_H
 8
 9#include <linux/types.h>
10#include <asm/mmio.h>
11
12#ifdef CONFIG_RISCV_M_MODE
13/*
14 * This lives in the CLINT driver, but is accessed directly by timex.h to avoid
15 * any overhead when accessing the MMIO timer.
16 *
17 * The ISA defines mtime as a 64-bit memory-mapped register that increments at
18 * a constant frequency, but it doesn't define some other constraints we depend
19 * on (most notably ordering constraints, but also some simpler stuff like the
20 * memory layout).  Thus, this is called "clint_time_val" instead of something
21 * like "riscv_mtime", to signify that these non-ISA assumptions must hold.
22 */
23extern u64 __iomem *clint_time_val;
24#endif
25
26#endif