[PATCH hyperv-next v7 11/11] PCI: hv: Get vPCI MSI IRQ domain from DeviceTree

[Roman Kisel <romank@linux.microsoft.com>]

The hyperv-pci driver uses ACPI for MSI IRQ domain configuration on
arm64. It won't be able to do that in the VTL mode where only DeviceTree
can be used.

Update the hyperv-pci driver to get vPCI MSI IRQ domain in the DeviceTree
case, too.

Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/controller/pci-hyperv.c | 72 ++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 6084b38bdda1..2d7de07bbf38 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -50,6 +50,7 @@
 #include <linux/irqdomain.h>
 #include <linux/acpi.h>
 #include <linux/sizes.h>
+#include <linux/of_irq.h>
 #include <asm/mshyperv.h>
 
 /*
@@ -817,9 +818,17 @@ static int hv_pci_vec_irq_gic_domain_alloc(struct irq_domain *domain,
 	int ret;
 
 	fwspec.fwnode = domain->parent->fwnode;
-	fwspec.param_count = 2;
-	fwspec.param[0] = hwirq;
-	fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
+	if (is_of_node(fwspec.fwnode)) {
+		/* SPI lines for OF translations start at offset 32 */
+		fwspec.param_count = 3;
+		fwspec.param[0] = 0;
+		fwspec.param[1] = hwirq - 32;
+		fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
+	} else {
+		fwspec.param_count = 2;
+		fwspec.param[0] = hwirq;
+		fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
+	}
 
 	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 	if (ret)
@@ -887,10 +896,46 @@ static const struct irq_domain_ops hv_pci_domain_ops = {
 	.activate = hv_pci_vec_irq_domain_activate,
 };
 
+#ifdef CONFIG_OF
+
+static struct irq_domain *hv_pci_of_irq_domain_parent(void)
+{
+	struct device_node *parent;
+	struct irq_domain *domain;
+
+	parent = of_irq_find_parent(hv_get_vmbus_root_device()->of_node);
+	if (!parent)
+		return NULL;
+	domain = irq_find_host(parent);
+	of_node_put(parent);
+
+	return domain;
+}
+
+#endif
+
+#ifdef CONFIG_ACPI
+
+static struct irq_domain *hv_pci_acpi_irq_domain_parent(void)
+{
+	acpi_gsi_domain_disp_fn gsi_domain_disp_fn;
+
+	if (acpi_irq_model != ACPI_IRQ_MODEL_GIC)
+		return NULL;
+	gsi_domain_disp_fn = acpi_get_gsi_dispatcher();
+	if (!gsi_domain_disp_fn)
+		return NULL;
+	return irq_find_matching_fwnode(gsi_domain_disp_fn(0),
+				     DOMAIN_BUS_ANY);
+}
+
+#endif
+
 static int hv_pci_irqchip_init(void)
 {
 	static struct hv_pci_chip_data *chip_data;
 	struct fwnode_handle *fn = NULL;
+	struct irq_domain *irq_domain_parent = NULL;
 	int ret = -ENOMEM;
 
 	chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
@@ -907,9 +952,24 @@ static int hv_pci_irqchip_init(void)
 	 * way to ensure that all the corresponding devices are also gone and
 	 * no interrupts will be generated.
 	 */
-	hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
-							  fn, &hv_pci_domain_ops,
-							  chip_data);
+#ifdef CONFIG_ACPI
+	if (!acpi_disabled)
+		irq_domain_parent = hv_pci_acpi_irq_domain_parent();
+#endif
+#ifdef CONFIG_OF
+	if (!irq_domain_parent)
+		irq_domain_parent = hv_pci_of_irq_domain_parent();
+#endif
+	if (!irq_domain_parent) {
+		WARN_ONCE(1, "Invalid firmware configuration for VMBus interrupts\n");
+		ret = -EINVAL;
+		goto free_chip;
+	}
+
+	hv_msi_gic_irq_domain = irq_domain_create_hierarchy(irq_domain_parent, 0,
+		HV_PCI_MSI_SPI_NR,
+		fn, &hv_pci_domain_ops,
+		chip_data);
 
 	if (!hv_msi_gic_irq_domain) {
 		pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
-- 
2.43.0