ACPI: bus: Add acpi_riscv_init() function

Add a new function for RISC-V to do architecture specific initialization
similar to acpi_arm_init(). Some of the ACPI tables are architecture
specific and there is no reason trying to find them on other
architectures. So, add acpi_riscv_init() similar to acpi_arm_init().
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://patch.msgid.link/20240812005929.113499-4-sunilvl@ventanamicro.comSigned-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/bus.c

@@ -1459,6 +1459,7 @@ static int __init acpi_init(void)
 	acpi_hest_init();
 	acpi_ghes_init();
 	acpi_arm_init();
+	acpi_riscv_init();
 	acpi_scan_init();
 	acpi_ec_init();
 	acpi_debugfs_init();

drivers/acpi/riscv/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
-obj-y					+= rhct.o
+obj-y					+= rhct.o init.o
 obj-$(CONFIG_ACPI_PROCESSOR_IDLE)	+= cpuidle.o
 obj-$(CONFIG_ACPI_CPPC_LIB)		+= cppc.o

drivers/acpi/riscv/init.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023-2024, Ventana Micro Systems Inc
+ *	Author: Sunil V L <sunilvl@ventanamicro.com>
+ */
+
+#include <linux/acpi.h>
+
+void __init acpi_riscv_init(void)
+{
+}

include/linux/acpi.h

@@ -1531,6 +1531,12 @@ void acpi_arm_init(void);
 static inline void acpi_arm_init(void) { }
 #endif
 
+#ifdef CONFIG_RISCV
+void acpi_riscv_init(void);
+#else
+static inline void acpi_riscv_init(void) { }
+#endif
+
 #ifdef CONFIG_ACPI_PCC
 void acpi_init_pcc(void);
 #else