genirq/msi: Extend msi_parent_ops

Supporting per device MSI domains on ARM64, RISC-V and the zoo of
interrupt mechanisms needs a bit more information than what the
initial x86 implementation provides.

Add the following fields:

  - required_flags: 	The flags which a parent domain requires to be set
  - bus_select_token:	The bus token of the parent domain for select()
  - bus_select_mask:	A bitmask of supported child domain bus types

This allows to provide library functions which can be shared between
various interrupt chip implementations and avoids replicating mostly
similar code all over the place.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240127161753.114685-4-apatel@ventanamicro.com

include/linux/msi.h

@@ -572,6 +572,11 @@ enum {
  * struct msi_parent_ops - MSI parent domain callbacks and configuration info
  *
  * @supported_flags:	Required: The supported MSI flags of the parent domain
+ * @required_flags:	Optional: The required MSI flags of the parent MSI domain
+ * @bus_select_token:	Optional: The bus token of the real parent domain for
+ *			irq_domain::select()
+ * @bus_select_mask:	Optional: A mask of supported BUS_DOMAINs for
+ *			irq_domain::select()
  * @prefix:		Optional: Prefix for the domain and chip name
  * @init_dev_msi_info:	Required: Callback for MSI parent domains to setup parent
  *			domain specific domain flags, domain ops and interrupt chip
@@ -579,6 +584,9 @@ enum {
  */
 struct msi_parent_ops {
 	u32		supported_flags;
+	u32		required_flags;
+	u32		bus_select_token;
+	u32		bus_select_mask;
 	const char	*prefix;
 	bool		(*init_dev_msi_info)(struct device *dev, struct irq_domain *domain,
 					     struct irq_domain *msi_parent_domain,