[PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Anup Patel <apatel@xxxxxxxxxxxxxxxx>]

We add a common riscv_get_intc_hartid() which help device drivers to
get hartid of the HART associated with a INTC (i.e. local interrupt
controller) fwnode. This new function is more generic compared to
the existing riscv_of_parent_hartid() function hence we also replace
use of riscv_of_parent_hartid() with riscv_get_intc_hartid().

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
 arch/riscv/include/asm/processor.h |  4 +++-
 arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
 drivers/irqchip/irq-riscv-intc.c   |  2 +-
 drivers/irqchip/irq-sifive-plic.c  |  3 ++-
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 3e23e1786d05..3ce64b3bea4e 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
 struct device_node;
 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_early_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_get_intc_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 157ace8b262c..ee583eac3c5b 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
  * To achieve this, we walk up the DT tree until we find an active
  * RISC-V core (HART) node and extract the cpuid from it.
  */
-int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
+static int riscv_of_parent_hartid(struct device_node *node,
+				  unsigned long *hartid)
 {
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
@@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 	return -1;
 }
 
+/* Find hart ID of the INTC fwnode. */
+int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
+{
+	/* Extend this function ACPI in the future. */
+	if (!is_of_node(node))
+		return -ENODEV;
+
+	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)
diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 4adeee1bc391..65f4a2afb381 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
 	int rc;
 	unsigned long hartid;
 
-	rc = riscv_of_parent_hartid(node, &hartid);
+	rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
 	if (rc < 0) {
 		pr_warn("unable to find hart id for %pOF\n", node);
 		return 0;
diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index e1484905b7bd..56b0544b1f27 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
 			continue;
 		}
 
-		error = riscv_of_parent_hartid(parent.np, &hartid);
+		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
+					      &hartid);
 		if (error < 0) {
 			pr_warn("failed to parse hart ID for context %d.\n", i);
 			continue;
-- 
2.34.1