irqchip/riscv-imsic: Move to common MSI library

Simplify the leaf MSI domain handling in the RISC-V IMSIC driver by
using msi_lib_init_dev_msi_info() and msi_lib_irq_domain_select()
provided by the common MSI library.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250217085657.789309-4-apatel@ventanamicro.com

Author: KAGA-KOKO

drivers/irqchip/Kconfig

@@ -589,13 +589,7 @@ config RISCV_IMSIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_IRQ_MATRIX_ALLOCATOR
 	select GENERIC_MSI_IRQ
-
-config RISCV_IMSIC_PCI
-	bool
-	depends on RISCV_IMSIC
-	depends on PCI
-	depends on PCI_MSI
-	default RISCV_IMSIC
+	select IRQ_MSI_LIB
 
 config SIFIVE_PLIC
 	bool

drivers/irqchip/irq-riscv-imsic-platform.c

@@ -20,6 +20,7 @@
 #include <linux/spinlock.h>
 #include <linux/smp.h>
 
+#include "irq-msi-lib.h"
 #include "irq-riscv-imsic-state.h"
 
 static bool imsic_cpu_page_phys(unsigned int cpu, unsigned int guest_index,
@@ -174,22 +175,6 @@ static void imsic_irq_domain_free(struct irq_domain *domain, unsigned int virq,
 	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
 }
 
-static int imsic_irq_domain_select(struct irq_domain *domain, struct irq_fwspec *fwspec,
-				   enum irq_domain_bus_token bus_token)
-{
-	const struct msi_parent_ops *ops = domain->msi_parent_ops;
-	u32 busmask = BIT(bus_token);
-
-	if (fwspec->fwnode != domain->fwnode || fwspec->param_count != 0)
-		return 0;
-
-	/* Handle pure domain searches */
-	if (bus_token == ops->bus_select_token)
-		return 1;
-
-	return !!(ops->bus_select_mask & busmask);
-}
-
 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
 static void imsic_irq_debug_show(struct seq_file *m, struct irq_domain *d,
 				 struct irq_data *irqd, int ind)
@@ -206,110 +191,21 @@ static void imsic_irq_debug_show(struct seq_file *m, struct irq_domain *d,
 static const struct irq_domain_ops imsic_base_domain_ops = {
 	.alloc		= imsic_irq_domain_alloc,
 	.free		= imsic_irq_domain_free,
-	.select		= imsic_irq_domain_select,
+	.select		= msi_lib_irq_domain_select,
 #ifdef CONFIG_GENERIC_IRQ_DEBUGFS
 	.debug_show	= imsic_irq_debug_show,
 #endif
 };
 
-#ifdef CONFIG_RISCV_IMSIC_PCI
-
-static void imsic_pci_mask_irq(struct irq_data *d)
-{
-	pci_msi_mask_irq(d);
-	irq_chip_mask_parent(d);
-}
-
-static void imsic_pci_unmask_irq(struct irq_data *d)
-{
-	irq_chip_unmask_parent(d);
-	pci_msi_unmask_irq(d);
-}
-
-#define MATCH_PCI_MSI		BIT(DOMAIN_BUS_PCI_MSI)
-
-#else
-
-#define MATCH_PCI_MSI		0
-
-#endif
-
-static bool imsic_init_dev_msi_info(struct device *dev,
-				    struct irq_domain *domain,
-				    struct irq_domain *real_parent,
-				    struct msi_domain_info *info)
-{
-	const struct msi_parent_ops *pops = real_parent->msi_parent_ops;
-
-	/* MSI parent domain specific settings */
-	switch (real_parent->bus_token) {
-	case DOMAIN_BUS_NEXUS:
-		if (WARN_ON_ONCE(domain != real_parent))
-			return false;
-#ifdef CONFIG_SMP
-		info->chip->irq_set_affinity = irq_chip_set_affinity_parent;
-#endif
-		break;
-	default:
-		WARN_ON_ONCE(1);
-		return false;
-	}
-
-	/* Is the target supported? */
-	switch (info->bus_token) {
-#ifdef CONFIG_RISCV_IMSIC_PCI
-	case DOMAIN_BUS_PCI_DEVICE_MSI:
-	case DOMAIN_BUS_PCI_DEVICE_MSIX:
-		info->chip->irq_mask = imsic_pci_mask_irq;
-		info->chip->irq_unmask = imsic_pci_unmask_irq;
-		break;
-#endif
-	case DOMAIN_BUS_DEVICE_MSI:
-		/*
-		 * Per-device MSI should never have any MSI feature bits
-		 * set. It's sole purpose is to create a dumb interrupt
-		 * chip which has a device specific irq_write_msi_msg()
-		 * callback.
-		 */
-		if (WARN_ON_ONCE(info->flags))
-			return false;
-
-		/* Core managed MSI descriptors */
-		info->flags |= MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS |
-			       MSI_FLAG_FREE_MSI_DESCS;
-		break;
-	case DOMAIN_BUS_WIRED_TO_MSI:
-		break;
-	default:
-		WARN_ON_ONCE(1);
-		return false;
-	}
-
-	/* Use hierarchial chip operations re-trigger */
-	info->chip->irq_retrigger = irq_chip_retrigger_hierarchy;
-
-	/*
-	 * Mask out the domain specific MSI feature flags which are not
-	 * supported by the real parent.
-	 */
-	info->flags &= pops->supported_flags;
-
-	/* Enforce the required flags */
-	info->flags |= pops->required_flags;
-
-	return true;
-}
-
-#define MATCH_PLATFORM_MSI		BIT(DOMAIN_BUS_PLATFORM_MSI)
-
 static const struct msi_parent_ops imsic_msi_parent_ops = {
 	.supported_flags	= MSI_GENERIC_FLAGS_MASK |
 				  MSI_FLAG_PCI_MSIX,
 	.required_flags		= MSI_FLAG_USE_DEF_DOM_OPS |
-				  MSI_FLAG_USE_DEF_CHIP_OPS,
+				  MSI_FLAG_USE_DEF_CHIP_OPS |
+				  MSI_FLAG_PCI_MSI_MASK_PARENT,
 	.bus_select_token	= DOMAIN_BUS_NEXUS,
 	.bus_select_mask	= MATCH_PCI_MSI | MATCH_PLATFORM_MSI,
-	.init_dev_msi_info	= imsic_init_dev_msi_info,
+	.init_dev_msi_info	= msi_lib_init_dev_msi_info,
 };
 
 int imsic_irqdomain_init(void)