[PATCH V5 15/21] irqchip/riscv-intc: Add ACPI support

Sunil V L
2023-05-08T11:55:10Z

Add support for initializing the RISC-V INTC driver on ACPI
platforms.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
drivers/irqchip/irq-riscv-intc.c | 70 +++++++++++++++++++++++++-------
1 file changed, 55 insertions(+), 15 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index f229e3e66387..4adeee1bc391 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -6,6 +6,7 @@
*/

#define pr_fmt(fmt) "riscv-intc: " fmt
+#include <linux/acpi.h>
#include <linux/atomic.h>
#include <linux/bits.h>
#include <linux/cpu.h>
@@ -112,6 +113,30 @@ static struct fwnode_handle *riscv_intc_hwnode(void)
return intc_domain->fwnode;
}

+static int __init riscv_intc_init_common(struct fwnode_handle *fn)
+{
+ int rc;
+
+ intc_domain = irq_domain_create_linear(fn, BITS_PER_LONG,
+ &riscv_intc_domain_ops, NULL);
+ if (!intc_domain) {
+ pr_err("unable to add IRQ domain\n");
+ return -ENXIO;
+ }
+
+ rc = set_handle_irq(&riscv_intc_irq);
+ if (rc) {
+ pr_err("failed to set irq handler\n");
+ return rc;
+ }
+
+ riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
+
+ pr_info("%d local interrupts mapped\n", BITS_PER_LONG);
+
+ return 0;
+}
+
static int __init riscv_intc_init(struct device_node *node,
struct device_node *parent)
{
@@ -133,24 +158,39 @@ static int __init riscv_intc_init(struct device_node *node,
if (riscv_hartid_to_cpuid(hartid) != smp_processor_id())
return 0;

- intc_domain = irq_domain_add_linear(node, BITS_PER_LONG,
- &riscv_intc_domain_ops, NULL);
- if (!intc_domain) {
- pr_err("unable to add IRQ domain\n");
- return -ENXIO;
- }
+ return riscv_intc_init_common(of_node_to_fwnode(node));
+}

- rc = set_handle_irq(&riscv_intc_irq);
- if (rc) {
- pr_err("failed to set irq handler\n");
- return rc;
- }
+IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init);

- riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
+#ifdef CONFIG_ACPI

- pr_info("%d local interrupts mapped\n", BITS_PER_LONG);
+static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct fwnode_handle *fn;
+ struct acpi_madt_rintc *rintc;

- return 0;
+ rintc = (struct acpi_madt_rintc *)header;
+
+ /*
+ * The ACPI MADT will have one INTC for each CPU (or HART)
+ * so riscv_intc_acpi_init() function will be called once
+ * for each INTC. We only do INTC initialization
+ * for the INTC belonging to the boot CPU (or boot HART).
+ */
+ if (riscv_hartid_to_cpuid(rintc->hart_id) != smp_processor_id())
+ return 0;
+
+ fn = irq_domain_alloc_named_fwnode("RISCV-INTC");
+ if (!fn) {
+ pr_err("unable to allocate INTC FW node\n");
+ return -ENOMEM;
+ }
+
+ return riscv_intc_init_common(fn);
}

-IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init);
+IRQCHIP_ACPI_DECLARE(riscv_intc, ACPI_MADT_TYPE_RINTC, NULL,
+ ACPI_MADT_RINTC_VERSION_V1, riscv_intc_acpi_init);
+#endif