iommu/amd: Convert to msi_create_parent_irq_domain() helper

Now that we have a concise helper to create an MSI parent domain,
switch the AMD IOMMU remapping over to that.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nam Cao <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241204124549.607054-9-maz@kernel.org
Link: https://lore.kernel.org/r/92e5ae97a03e4ffc272349d0863cd2cc8f904c44.1750858125.git.namcao@linutronix.de
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

Author: Marc Zyngier

drivers/iommu/amd/Kconfig

@@ -7,6 +7,7 @@ config AMD_IOMMU
 	select PCI_ATS
 	select PCI_PRI
 	select PCI_PASID
+	select IRQ_MSI_LIB
 	select MMU_NOTIFIER
 	select IOMMU_API
 	select IOMMU_IOVA

drivers/iommu/amd/iommu.c

@@ -25,6 +25,7 @@
 #include <linux/notifier.h>
 #include <linux/export.h>
 #include <linux/irq.h>
+#include <linux/irqchip/irq-msi-lib.h>
 #include <linux/msi.h>
 #include <linux/irqdomain.h>
 #include <linux/percpu.h>
@@ -3970,29 +3971,30 @@ static struct irq_chip amd_ir_chip = {
 
 static const struct msi_parent_ops amdvi_msi_parent_ops = {
 	.supported_flags	= X86_VECTOR_MSI_FLAGS_SUPPORTED | MSI_FLAG_MULTI_PCI_MSI,
+	.bus_select_token	= DOMAIN_BUS_AMDVI,
+	.bus_select_mask	= MATCH_PCI_MSI,
 	.prefix			= "IR-",
 	.init_dev_msi_info	= msi_parent_init_dev_msi_info,
 };
 
 int amd_iommu_create_irq_domain(struct amd_iommu *iommu)
 {
-	struct fwnode_handle *fn;
+	struct irq_domain_info info = {
+		.fwnode		= irq_domain_alloc_named_id_fwnode("AMD-IR", iommu->index),
+		.ops		= &amd_ir_domain_ops,
+		.domain_flags	= IRQ_DOMAIN_FLAG_ISOLATED_MSI,
+		.host_data	= iommu,
+		.parent		= arch_get_ir_parent_domain(),
+	};
 
-	fn = irq_domain_alloc_named_id_fwnode("AMD-IR", iommu->index);
-	if (!fn)
+	if (!info.fwnode)
 		return -ENOMEM;
-	iommu->ir_domain = irq_domain_create_hierarchy(arch_get_ir_parent_domain(), 0, 0,
-						       fn, &amd_ir_domain_ops, iommu);
+
+	iommu->ir_domain = msi_create_parent_irq_domain(&info, &amdvi_msi_parent_ops);
 	if (!iommu->ir_domain) {
-		irq_domain_free_fwnode(fn);
+		irq_domain_free_fwnode(info.fwnode);
 		return -ENOMEM;
 	}
-
-	irq_domain_update_bus_token(iommu->ir_domain,  DOMAIN_BUS_AMDVI);
-	iommu->ir_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT |
-				   IRQ_DOMAIN_FLAG_ISOLATED_MSI;
-	iommu->ir_domain->msi_parent_ops = &amdvi_msi_parent_ops;
-
 	return 0;
 }