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authorPasha <pasha@member.fsf.org>2024-02-20 18:55:36 +0000
committerPasha <pasha@member.fsf.org>2024-02-20 18:55:36 +0000
commit6fca8abef7e6d7be1a9e6d93dd0f2b7fbc5b28e5 (patch)
tree9f5ccbaa6ec19ff5a42d9b3cde01f739e1d7c77d /riscv/include/asm/clint.h
parent5e0b8d508ed51004bd836384293be00950ee62c9 (diff)
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initial risc-v exampleHEADmaster
Diffstat (limited to 'riscv/include/asm/clint.h')
-rw-r--r--riscv/include/asm/clint.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/riscv/include/asm/clint.h b/riscv/include/asm/clint.h
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+/* 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