PCI: endpoint: pci-epf-test: Expose supported IRQ types in CAPS register

Expose the supported IRQ types in the CAPS register.

This way, the host side driver (drivers/misc/pci_endpoint_test.c) can
know which IRQ types that the endpoint supports.

The host side driver will make use of this information in a follow-up
commit.

Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Link: https://lore.kernel.org/r/20250310111016.859445-15-cassel@kernel.org

Author: floatious

drivers/pci/endpoint/functions/pci-epf-test.c

@@ -45,6 +45,9 @@
 #define TIMER_RESOLUTION		1
 
 #define CAP_UNALIGNED_ACCESS		BIT(0)
+#define CAP_MSI				BIT(1)
+#define CAP_MSIX			BIT(2)
+#define CAP_INTX			BIT(3)
 
 static struct workqueue_struct *kpcitest_workqueue;
 
@@ -753,6 +756,15 @@ static void pci_epf_test_set_capabilities(struct pci_epf *epf)
 	if (epc->ops->align_addr)
 		caps |= CAP_UNALIGNED_ACCESS;
 
+	if (epf_test->epc_features->msi_capable)
+		caps |= CAP_MSI;
+
+	if (epf_test->epc_features->msix_capable)
+		caps |= CAP_MSIX;
+
+	if (epf_test->epc_features->intx_capable)
+		caps |= CAP_INTX;
+
 	reg->caps = cpu_to_le32(caps);
 }