1 files changed, 91 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h
new file mode 100644
index 000000000..a06697846
--- /dev/null
+++ b/arch/riscv/include/asm/timex.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ */
+
+#ifndef _ASM_RISCV_TIMEX_H
+#define _ASM_RISCV_TIMEX_H
+
+#include <asm/csr.h>
+
+typedef unsigned long cycles_t;
+
+#ifdef CONFIG_RISCV_M_MODE
+
+#include <asm/clint.h>
+
+#ifdef CONFIG_64BIT
+static inline cycles_t get_cycles(void)
+{
+	return readq_relaxed(clint_time_val);
+}
+#else /* !CONFIG_64BIT */
+static inline u32 get_cycles(void)
+{
+	return readl_relaxed(((u32 *)clint_time_val));
+}
+#define get_cycles get_cycles
+
+static inline u32 get_cycles_hi(void)
+{
+	return readl_relaxed(((u32 *)clint_time_val) + 1);
+}
+#define get_cycles_hi get_cycles_hi
+#endif /* CONFIG_64BIT */
+
+/*
+ * Much like MIPS, we may not have a viable counter to use at an early point
+ * in the boot process. Unfortunately we don't have a fallback, so instead
+ * we just return 0.
+ */
+static inline unsigned long random_get_entropy(void)
+{
+	if (unlikely(clint_time_val == NULL))
+		return random_get_entropy_fallback();
+	return get_cycles();
+}
+#define random_get_entropy()	random_get_entropy()
+
+#else /* CONFIG_RISCV_M_MODE */
+
+static inline cycles_t get_cycles(void)
+{
+	return csr_read(CSR_TIME);
+}
+#define get_cycles get_cycles
+
+static inline u32 get_cycles_hi(void)
+{
+	return csr_read(CSR_TIMEH);
+}
+#define get_cycles_hi get_cycles_hi
+
+#endif /* !CONFIG_RISCV_M_MODE */
+
+#ifdef CONFIG_64BIT
+static inline u64 get_cycles64(void)
+{
+	return get_cycles();
+}
+#else /* CONFIG_64BIT */
+static inline u64 get_cycles64(void)
+{
+	u32 hi, lo;
+
+	do {
+		hi = get_cycles_hi();
+		lo = get_cycles();
+	} while (hi != get_cycles_hi());
+
+	return ((u64)hi << 32) | lo;
+}
+#endif /* CONFIG_64BIT */
+
+#define ARCH_HAS_READ_CURRENT_TIMER
+static inline int read_current_timer(unsigned long *timer_val)
+{
+	*timer_val = get_cycles();
+	return 0;
+}
+
+#endif /* _ASM_RISCV_TIMEX_H */