1 files changed, 40 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/htif.h b/arch/riscv/include/asm/htif.h
new file mode 100644
index 0000000000..b35afdd98e
--- /dev/null
+++ b/arch/riscv/include/asm/htif.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Ahmad Fatoum, Pengutronix
+ */
+
+#ifndef __ASM_HTIF_LL__
+#define __ASM_HTIF_LL__
+
+#define HTIF_DEFAULT_BASE_ADDR		0x40008000
+
+#define HTIF_DEV_SYSCALL		0
+#define		HTIF_CMD_SYSCALL	0
+
+#define HTIF_DEV_CONSOLE		1 /* blocking character device */
+#define		HTIF_CMD_GETCHAR	0
+#define		HTIF_CMD_PUTCHAR	1
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+#include <io-64-nonatomic-lo-hi.h>
+
+static inline void __htif_tohost(void __iomem *htif, u8 device, u8 command, u64 arg)
+{
+	writeq(((u64)device << 56) | ((u64)command << 48) | arg, htif);
+}
+
+static inline void htif_tohost(u8 device, u8 command, u64 arg)
+{
+	__htif_tohost(IOMEM(HTIF_DEFAULT_BASE_ADDR), device, command, arg);
+}
+
+static inline void htif_putc(void __iomem *base, int c)
+{
+	__htif_tohost(base, HTIF_DEV_CONSOLE, HTIF_CMD_PUTCHAR, c);
+}
+
+#endif
+
+#endif