[irqchip: irq/irqchip-next] irqchip/riscv-intc: Allow drivers to directly discover INTC hwnode

[irqchip-bot for Anup Patel]

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID:     0c60a31ce62ca3e93550868fd699dfc4dfc4e795
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/0c60a31ce62ca3e93550868fd699dfc4dfc4e795
Author:        Anup Patel <apatel@xxxxxxxxxxxxxxxx>
AuthorDate:    Tue, 28 Mar 2023 09:22:18 +05:30
Committer:     Marc Zyngier <maz@xxxxxxxxxx>
CommitterDate: Sat, 08 Apr 2023 11:26:24 +01:00

irqchip/riscv-intc: Allow drivers to directly discover INTC hwnode

Various RISC-V drivers (such as SBI IPI, SBI Timer, SBI PMU, and
KVM RISC-V) don't have associated DT node but these drivers need
standard per-CPU (local) interrupts defined by the RISC-V privileged
specification.

We add riscv_get_intc_hwnode() in arch/riscv which allows RISC-V
drivers not having DT node to discover INTC hwnode which in-turn
helps these drivers to map per-CPU (local) interrupts provided
by the INTC driver.

Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230328035223.1480939-3-apatel@xxxxxxxxxxxxxxxx
---
 arch/riscv/include/asm/irq.h     |  4 ++++
 arch/riscv/kernel/irq.c          | 18 ++++++++++++++++++
 drivers/irqchip/irq-riscv-intc.c |  7 +++++++
 3 files changed, 29 insertions(+)

diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
index e4c4355..43b9ebf 100644
--- a/arch/riscv/include/asm/irq.h
+++ b/arch/riscv/include/asm/irq.h
@@ -12,6 +12,10 @@
 
 #include <asm-generic/irq.h>
 
+void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void));
+
+struct fwnode_handle *riscv_get_intc_hwnode(void);
+
 extern void __init init_IRQ(void);
 
 #endif /* _ASM_RISCV_IRQ_H */
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
index 7207fa0..96d3171 100644
--- a/arch/riscv/kernel/irq.c
+++ b/arch/riscv/kernel/irq.c
@@ -7,9 +7,27 @@
 
 #include <linux/interrupt.h>
 #include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
 #include <linux/seq_file.h>
 #include <asm/smp.h>
 
+static struct fwnode_handle *(*__get_intc_node)(void);
+
+void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void))
+{
+	__get_intc_node = fn;
+}
+
+struct fwnode_handle *riscv_get_intc_hwnode(void)
+{
+	if (__get_intc_node)
+		return __get_intc_node();
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode);
+
 int arch_show_interrupts(struct seq_file *p, int prec)
 {
 	show_ipi_stats(p, prec);
diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 499e5f8..9066467 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -92,6 +92,11 @@ static const struct irq_domain_ops riscv_intc_domain_ops = {
 	.xlate	= irq_domain_xlate_onecell,
 };
 
+static struct fwnode_handle *riscv_intc_hwnode(void)
+{
+	return intc_domain->fwnode;
+}
+
 static int __init riscv_intc_init(struct device_node *node,
 				  struct device_node *parent)
 {
@@ -126,6 +131,8 @@ static int __init riscv_intc_init(struct device_node *node,
 		return rc;
 	}
 
+	riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
+
 	cpuhp_setup_state(CPUHP_AP_IRQ_RISCV_STARTING,
 			  "irqchip/riscv/intc:starting",
 			  riscv_intc_cpu_starting,