genirq/msi: Add bus token to struct msi_domain_info

Add a bus token member to struct msi_domain_info and let
msi_create_irq_domain() set the bus token.

That allows to remove the bus token updates at the call sites.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20221111122014.294554462@linutronix.de

include/linux/msi.h

@@ -16,6 +16,7 @@
  * abuse. The only function which is relevant for drivers is msi_get_virq().
  */
 
+#include <linux/irqdomain_defs.h>
 #include <linux/cpumask.h>
 #include <linux/xarray.h>
 #include <linux/mutex.h>
@@ -365,6 +366,7 @@ struct msi_domain_ops {
 /**
  * struct msi_domain_info - MSI interrupt domain data
  * @flags:		Flags to decribe features and capabilities
+ * @bus_token:		The domain bus token
  * @ops:		The callback data structure
  * @chip:		Optional: associated interrupt chip
  * @chip_data:		Optional: associated interrupt chip data
@@ -374,14 +376,15 @@ struct msi_domain_ops {
  * @data:		Optional: domain specific data
  */
 struct msi_domain_info {
-	u32			flags;
-	struct msi_domain_ops	*ops;
-	struct irq_chip		*chip;
-	void			*chip_data;
-	irq_flow_handler_t	handler;
-	void			*handler_data;
-	const char		*handler_name;
-	void			*data;
+	u32				flags;
+	enum irq_domain_bus_token	bus_token;
+	struct msi_domain_ops		*ops;
+	struct irq_chip			*chip;
+	void				*chip_data;
+	irq_flow_handler_t		handler;
+	void				*handler_data;
+	const char			*handler_name;
+	void				*data;
 };
 
 /* Flags for msi_domain_info */

kernel/irq/msi.c

@@ -694,8 +694,11 @@ struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode,
 	domain = irq_domain_create_hierarchy(parent, IRQ_DOMAIN_FLAG_MSI, 0,
 					     fwnode, &msi_domain_ops, info);
 
-	if (domain && !domain->name && info->chip)
-		domain->name = info->chip->name;
+	if (domain) {
+		if (!domain->name && info->chip)
+			domain->name = info->chip->name;
+		irq_domain_update_bus_token(domain, info->bus_token);
+	}
 
 	return domain;
 }