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Diffstat (limited to '')
-rw-r--r-- | arch/riscv/include/asm/clint.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/clint.h b/arch/riscv/include/asm/clint.h new file mode 100644 index 000000000..0789fd37b --- /dev/null +++ b/arch/riscv/include/asm/clint.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2020 Google, Inc + */ + +#ifndef _ASM_RISCV_CLINT_H +#define _ASM_RISCV_CLINT_H + +#include <linux/types.h> +#include <asm/mmio.h> + +#ifdef CONFIG_RISCV_M_MODE +/* + * This lives in the CLINT driver, but is accessed directly by timex.h to avoid + * any overhead when accessing the MMIO timer. + * + * The ISA defines mtime as a 64-bit memory-mapped register that increments at + * a constant frequency, but it doesn't define some other constraints we depend + * on (most notably ordering constraints, but also some simpler stuff like the + * memory layout). Thus, this is called "clint_time_val" instead of something + * like "riscv_mtime", to signify that these non-ISA assumptions must hold. + */ +extern u64 __iomem *clint_time_val; +#endif + +#endif |