[PATCH v3 01/11] RISC-V: Add riscv_fw_parent_hartid() function

[Anup Patel]

We add common riscv_fw_parent_hartid() which help device drivers
to get parent hartid of the INTC (i.e. local interrupt controller)
fwnode. Currently, this new function only supports device tree
but it can be extended to support ACPI as well.

Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
 arch/riscv/include/asm/processor.h |  3 +++
 arch/riscv/kernel/cpu.c            | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 94a0590c6971..6fb8bbec8459 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -77,6 +77,9 @@ struct device_node;
 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
 
+struct fwnode_handle;
+int riscv_fw_parent_hartid(struct fwnode_handle *node, unsigned long *hartid);
+
 extern void riscv_fill_hwcap(void);
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 5de6fb703cc2..1adbe48b2b58 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -73,6 +73,18 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 	return -1;
 }
 
+/* Find hart ID of the CPU fwnode under which given fwnode falls. */
+int riscv_fw_parent_hartid(struct fwnode_handle *node, unsigned long *hartid)
+{
+	/*
+	 * Currently, this function only supports DT but it can be
+	 * extended to support ACPI as well.
+	 */
+	if (!is_of_node(node))
+		return -EINVAL;
+	return riscv_of_parent_hartid(to_of_node(node), hartid);
+}
+
 DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
 
 unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
-- 
2.34.1