irqchip/irq-msi-lib: Prepare for PCI MSI/MSIX

Add the bus tokens for DOMAIN_BUS_PCI_DEVICE_MSI and
DOMAIN_BUS_PCI_DEVICE_MSIX to the common child init
function.

Provide the match mask which can be used by parent domain
implementation so the bitmask based child bus token match
works.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Shivamurthy Shastri <shivamurthy.shastri@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240623142234.964056815@linutronix.de

drivers/irqchip/irq-msi-lib.c

@@ -28,6 +28,7 @@ bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
 			       struct msi_domain_info *info)
 {
 	const struct msi_parent_ops *pops = real_parent->msi_parent_ops;
+	u32 required_flags;
 
 	/* Parent ops available? */
 	if (WARN_ON_ONCE(!pops))
@@ -46,8 +47,16 @@ bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
 		return false;
 	}
 
+	required_flags = pops->required_flags;
+
 	/* Is the target domain bus token supported? */
 	switch(info->bus_token) {
+	case DOMAIN_BUS_PCI_DEVICE_MSI:
+	case DOMAIN_BUS_PCI_DEVICE_MSIX:
+		if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_PCI_MSI)))
+			return false;
+
+		break;
 	default:
 		/*
 		 * This should never be reached. See
@@ -63,7 +72,7 @@ bool msi_lib_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
 	 */
 	info->flags			&= pops->supported_flags;
 	/* Enforce the required flags */
-	info->flags			|= pops->required_flags;
+	info->flags			|= required_flags;
 
 	/* Chip updates for all child bus types */
 	if (!info->chip->irq_eoi)

drivers/irqchip/irq-msi-lib.h

@@ -9,6 +9,12 @@
 #include <linux/irqdomain.h>
 #include <linux/msi.h>
 
+#ifdef CONFIG_PCI_MSI
+#define MATCH_PCI_MSI		BIT(DOMAIN_BUS_PCI_MSI)
+#else
+#define MATCH_PCI_MSI		(0)
+#endif
+
 int msi_lib_irq_domain_select(struct irq_domain *d, struct irq_fwspec *fwspec,
 			      enum irq_domain_bus_token bus_token);