[patch V2 15/40] irqchip/gic-msi-lib: Prepare for DEVICE MSI to replace platform MSI

[Thomas Gleixner]

Add the prerequisites for DEVICE MSI into the shared select() and child
domain init function. These domains are really trivial and just provide a
custom irq chip callback to write the MSI message.

Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
---
 drivers/irqchip/irq-gic-msi-lib.c |   13 +++++++++++++
 drivers/irqchip/irq-gic-msi-lib.h |    2 ++
 2 files changed, 15 insertions(+)

--- a/drivers/irqchip/irq-gic-msi-lib.c
+++ b/drivers/irqchip/irq-gic-msi-lib.c
@@ -55,6 +55,19 @@ bool gic_msi_lib_init_dev_msi_info(struc
 
 		pci_device_msi_mask_unmask_parent_enable();
 		break;
+	case DOMAIN_BUS_DEVICE_IMS:
+		/*
+		 * Per device IMS 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;
 	default:
 		/*
 		 * This should never be reached. See
--- a/drivers/irqchip/irq-gic-msi-lib.h
+++ b/drivers/irqchip/irq-gic-msi-lib.h
@@ -15,6 +15,8 @@
 #define MATCH_PCI_MSI		(0)
 #endif
 
+#define MATCH_PLATFORM_MSI	BIT(DOMAIN_BUS_PLATFORM_MSI)
+
 int gic_msi_lib_irq_domain_select(struct irq_domain *d, struct irq_fwspec *fwspec,
 				  enum irq_domain_bus_token bus_token);