[PATCH v7 01/15] 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().

Also, while we are here let us update riscv_of_parent_hartid() to
always return the hartid irrespective whether the CPU/HART DT node
is disabled or not.

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
---
 arch/riscv/include/asm/processor.h |  4 +++-
 arch/riscv/kernel/cpu.c            | 26 ++++++++++++++++++++------
 drivers/irqchip/irq-riscv-intc.c   |  2 +-
 drivers/irqchip/irq-sifive-plic.c  |  3 ++-
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index c950a8d9edef..662da1e112dd 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -79,7 +79,9 @@ 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 a2fc952318e9..c3eaa8a55bbe 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -81,21 +81,35 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har
  * 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)
 {
-	int rc;
-
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
-			rc = riscv_of_processor_hartid(node, hartid);
-			if (!rc)
-				return 0;
+			*hartid = (unsigned long)of_get_cpu_hwid(node, 0);
+			return 0;
 		}
 	}
 
 	return -1;
 }
 
+/* Find hart ID of the INTC fwnode. */
+int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
+{
+	int rc;
+	u64 temp;
+
+	if (!is_of_node(node)) {
+		rc = fwnode_property_read_u64_array(node, "hartid", &temp, 1);
+		if (!rc)
+			*hartid = temp;
+	} else
+		rc = riscv_of_parent_hartid(to_of_node(node), hartid);
+
+	return rc;
+}
+
 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