[RFC PATCH v3 15/17] ACPI: RISC-V: Create APLIC platform device

[Sunil V L <sunilvl@ventanamicro.com>]

Since APLIC needs to be a platform device, probe the MADT and create
platform devices for each APLIC in the system.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
 drivers/acpi/riscv/init.c |   2 +
 drivers/acpi/riscv/init.h |   5 ++
 drivers/acpi/riscv/irq.c  | 118 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 125 insertions(+)
 create mode 100644 drivers/acpi/riscv/init.h

diff --git a/drivers/acpi/riscv/init.c b/drivers/acpi/riscv/init.c
index b5807bbdb171..e7eff7ab1474 100644
--- a/drivers/acpi/riscv/init.c
+++ b/drivers/acpi/riscv/init.c
@@ -6,7 +6,9 @@
  */
 
 #include <linux/acpi.h>
+#include "init.h"
 
 void __init acpi_riscv_init(void)
 {
+	riscv_acpi_aplic_platform_init();
 }
diff --git a/drivers/acpi/riscv/init.h b/drivers/acpi/riscv/init.h
new file mode 100644
index 000000000000..17bcf0baaadb
--- /dev/null
+++ b/drivers/acpi/riscv/init.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <linux/init.h>
+
+void __init riscv_acpi_imsic_platform_init(void);
+void __init riscv_acpi_aplic_platform_init(void);
diff --git a/drivers/acpi/riscv/irq.c b/drivers/acpi/riscv/irq.c
index 36e0525b3235..d08a851ab6dc 100644
--- a/drivers/acpi/riscv/irq.c
+++ b/drivers/acpi/riscv/irq.c
@@ -6,7 +6,36 @@
  */
 
 #include <linux/acpi.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/platform_device.h>
 #include <linux/sort.h>
+#include "init.h"
+
+static LIST_HEAD(ext_intc_list);
+
+struct ext_intc_fwnode_list {
+	struct fwnode_handle *fwnode;
+	u32 gsi_base;
+	u32 nr_irqs;
+	struct list_head list;
+};
+
+struct fwnode_handle *ext_entc_get_gsi_domain_id(u32 gsi)
+{
+	struct ext_intc_fwnode_list *ext_intc_element;
+	struct list_head *i, *tmp;
+
+	/* Find the External Interrupt controller that manages this GSI. */
+	list_for_each_safe(i, tmp, &ext_intc_list) {
+		ext_intc_element = list_entry(i, struct ext_intc_fwnode_list, list);
+		if (gsi >= ext_intc_element->gsi_base &&
+		    gsi < (ext_intc_element->gsi_base + ext_intc_element->nr_irqs))
+			return ext_intc_element->fwnode;
+	}
+
+	return NULL;
+}
 
 static int irqchip_cmp_func(const void *in0, const void *in1)
 {
@@ -30,3 +59,92 @@ void arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr)
 		return;
 	sort(ape, nr, sizeof(*ape), irqchip_cmp_func, NULL);
 }
+
+static int __init irqchip_add_platform_device(char *irqchip_name, u32 irqchip_id,
+					      resource_size_t iomem_res_start,
+					      resource_size_t iomem_res_size,
+					      u32 gsi_base,
+					      u32 nr_irqs,
+					      union acpi_subtable_headers *header)
+{
+	struct ext_intc_fwnode_list *ext_intc_element;
+	struct platform_device *pdev;
+	struct fwnode_handle *fn;
+	struct resource *res;
+	int ret;
+
+	fn = irq_domain_alloc_named_id_fwnode(irqchip_name, irqchip_id);
+	if (!fn)
+		return -ENOMEM;
+
+	pdev = platform_device_alloc(irqchip_name, irqchip_id);
+	if (!pdev) {
+		irq_domain_free_fwnode(fn);
+		return -ENOMEM;
+	}
+
+	res = kcalloc(1, sizeof(*res), GFP_KERNEL);
+	if (!res) {
+		irq_domain_free_fwnode(fn);
+		platform_device_put(pdev);
+		return -ENOMEM;
+	}
+
+	ext_intc_element = kcalloc(1, sizeof(*ext_intc_element), GFP_KERNEL);
+	if (!ext_intc_element)
+		return -ENOMEM;
+
+	ext_intc_element->fwnode = fn;
+	ext_intc_element->gsi_base = gsi_base;
+	ext_intc_element->nr_irqs = nr_irqs;
+	list_add_tail(&ext_intc_element->list, &ext_intc_list);
+
+	res->start = iomem_res_start;
+	res->end = res->start + iomem_res_size - 1;
+	res->flags = IORESOURCE_MEM;
+	ret = platform_device_add_resources(pdev, res, 1);
+	/*
+	 * Resources are duplicated in platform_device_add_resources,
+	 * free their allocated memory
+	 */
+	kfree(res);
+
+	/*
+	 * Add copy of aplic pointer so that platform driver get aplic details.
+	 */
+	ret = platform_device_add_data(pdev, &header, sizeof(header));
+	if (ret) {
+		irq_domain_free_fwnode(fn);
+		platform_device_put(pdev);
+		return ret;
+	}
+
+	pdev->dev.fwnode = fn;
+	ret = platform_device_add(pdev);
+	if (ret) {
+		irq_domain_free_fwnode(fn);
+		platform_device_put(pdev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __init aplic_parse_madt(union acpi_subtable_headers *header,
+				   const unsigned long end)
+{
+	struct acpi_madt_aplic *aplic = (struct acpi_madt_aplic *)header;
+
+	return irqchip_add_platform_device("riscv-aplic",
+					   aplic->id,
+					   aplic->base_addr,
+					   aplic->size,
+					   aplic->gsi_base,
+					   aplic->num_sources,
+					   header);
+}
+
+void __init riscv_acpi_aplic_platform_init(void)
+{
+	acpi_table_parse_madt(ACPI_MADT_TYPE_APLIC, aplic_parse_madt, 0);
+}
-- 
2.39.2