irqchip/gic_v3_mbi: Switch over to parent domain

The MBI chip creates two MSI domains:
    - PCI/MSI
    - Platform device domain

Both have the MBI domain as parent and differ slightly in the interrupt
chip callbacks and the platform device domain supports level type
signaling.

Convert it over to the MSI parent domain mechanism by:

   - Providing the required templates
   
   - Implementing a custom init_dev_msi_info() callback which sets the chip
     callbacks and the level support flags depending on the domain bus token
     type of the per device domain.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240623142235.455849114@linutronix.de

drivers/irqchip/irq-gic-v3-mbi.c

@@ -18,6 +18,8 @@
 
 #include <linux/irqchip/arm-gic-v3.h>
 
+#include "irq-msi-lib.h"
+
 struct mbi_range {
 	u32			spi_start;
 	u32			nr_spis;
@@ -138,6 +140,7 @@ static void mbi_irq_domain_free(struct irq_domain *domain,
 }
 
 static const struct irq_domain_ops mbi_domain_ops = {
+	.select			= msi_lib_irq_domain_select,
 	.alloc			= mbi_irq_domain_alloc,
 	.free			= mbi_irq_domain_free,
 };
@@ -151,54 +154,6 @@ static void mbi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), msg);
 }
 
-#ifdef CONFIG_PCI_MSI
-/* PCI-specific irqchip */
-static void mbi_mask_msi_irq(struct irq_data *d)
-{
-	pci_msi_mask_irq(d);
-	irq_chip_mask_parent(d);
-}
-
-static void mbi_unmask_msi_irq(struct irq_data *d)
-{
-	pci_msi_unmask_irq(d);
-	irq_chip_unmask_parent(d);
-}
-
-static struct irq_chip mbi_msi_irq_chip = {
-	.name			= "MSI",
-	.irq_mask		= mbi_mask_msi_irq,
-	.irq_unmask		= mbi_unmask_msi_irq,
-	.irq_eoi		= irq_chip_eoi_parent,
-	.irq_compose_msi_msg	= mbi_compose_msi_msg,
-};
-
-static struct msi_domain_info mbi_msi_domain_info = {
-	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
-		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
-	.chip	= &mbi_msi_irq_chip,
-};
-
-static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
-				   struct irq_domain **pci_domain)
-{
-	*pci_domain = pci_msi_create_irq_domain(nexus_domain->parent->fwnode,
-						&mbi_msi_domain_info,
-						nexus_domain);
-	if (!*pci_domain)
-		return -ENOMEM;
-
-	return 0;
-}
-#else
-static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
-				   struct irq_domain **pci_domain)
-{
-	*pci_domain = NULL;
-	return 0;
-}
-#endif
-
 static void mbi_compose_mbi_msg(struct irq_data *data, struct msi_msg *msg)
 {
 	mbi_compose_msi_msg(data, msg);
@@ -210,28 +165,51 @@ static void mbi_compose_mbi_msg(struct irq_data *data, struct msi_msg *msg)
 	iommu_dma_compose_msi_msg(irq_data_get_msi_desc(data), &msg[1]);
 }
 
-/* Platform-MSI specific irqchip */
-static struct irq_chip mbi_pmsi_irq_chip = {
-	.name			= "pMSI",
-	.irq_set_type		= irq_chip_set_type_parent,
-	.irq_compose_msi_msg	= mbi_compose_mbi_msg,
-	.flags			= IRQCHIP_SUPPORTS_LEVEL_MSI,
-};
-
-static struct msi_domain_ops mbi_pmsi_ops = {
-};
+static bool mbi_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+				  struct irq_domain *real_parent, struct msi_domain_info *info)
+{
+	if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))
+		return false;
+
+	switch (info->bus_token) {
+	case DOMAIN_BUS_PCI_DEVICE_MSI:
+	case DOMAIN_BUS_PCI_DEVICE_MSIX:
+		info->chip->irq_compose_msi_msg = mbi_compose_msi_msg;
+		return true;
+
+	case DOMAIN_BUS_DEVICE_MSI:
+		info->chip->irq_compose_msi_msg = mbi_compose_mbi_msg;
+		info->chip->irq_set_type = irq_chip_set_type_parent;
+		info->chip->flags |= IRQCHIP_SUPPORTS_LEVEL_MSI;
+		info->flags |= MSI_FLAG_LEVEL_CAPABLE;
+		return true;
+
+	default:
+		WARN_ON_ONCE(1);
+		return false;
+	}
+}
 
-static struct msi_domain_info mbi_pmsi_domain_info = {
-	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
-		   MSI_FLAG_LEVEL_CAPABLE),
-	.ops	= &mbi_pmsi_ops,
-	.chip	= &mbi_pmsi_irq_chip,
+#define MBI_MSI_FLAGS_REQUIRED  (MSI_FLAG_USE_DEF_DOM_OPS |	\
+				 MSI_FLAG_USE_DEF_CHIP_OPS |	\
+				 MSI_FLAG_PCI_MSI_MASK_PARENT)
+
+#define MBI_MSI_FLAGS_SUPPORTED (MSI_GENERIC_FLAGS_MASK |	\
+				 MSI_FLAG_PCI_MSIX      |	\
+				 MSI_FLAG_MULTI_PCI_MSI)
+
+static const struct msi_parent_ops gic_v3_mbi_msi_parent_ops = {
+	.supported_flags	= MBI_MSI_FLAGS_SUPPORTED,
+	.required_flags		= MBI_MSI_FLAGS_REQUIRED,
+	.bus_select_token	= DOMAIN_BUS_NEXUS,
+	.bus_select_mask	= MATCH_PCI_MSI | MATCH_PLATFORM_MSI,
+	.prefix			= "MBI-",
+	.init_dev_msi_info	= mbi_init_dev_msi_info,
 };
 
-static int mbi_allocate_domains(struct irq_domain *parent)
+static int mbi_allocate_domain(struct irq_domain *parent)
 {
-	struct irq_domain *nexus_domain, *pci_domain, *plat_domain;
-	int err;
+	struct irq_domain *nexus_domain;
 
 	nexus_domain = irq_domain_create_hierarchy(parent, 0, 0, parent->fwnode,
 						   &mbi_domain_ops, NULL);
@@ -239,22 +217,8 @@ static int mbi_allocate_domains(struct irq_domain *parent)
 		return -ENOMEM;
 
 	irq_domain_update_bus_token(nexus_domain, DOMAIN_BUS_NEXUS);
-
-	err = mbi_allocate_pci_domain(nexus_domain, &pci_domain);
-
-	plat_domain = platform_msi_create_irq_domain(parent->fwnode,
-						     &mbi_pmsi_domain_info,
-						     nexus_domain);
-
-	if (err || !plat_domain) {
-		if (plat_domain)
-			irq_domain_remove(plat_domain);
-		if (pci_domain)
-			irq_domain_remove(pci_domain);
-		irq_domain_remove(nexus_domain);
-		return -ENOMEM;
-	}
-
+	nexus_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
+	nexus_domain->msi_parent_ops = &gic_v3_mbi_msi_parent_ops;
 	return 0;
 }
 
@@ -317,7 +281,7 @@ int __init mbi_init(struct fwnode_handle *fwnode, struct irq_domain *parent)
 
 	pr_info("Using MBI frame %pa\n", &mbi_phys_base);
 
-	ret = mbi_allocate_domains(parent);
+	ret = mbi_allocate_domain(parent);
 	if (ret)
 		goto err_free_mbi;