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[v18,05/15] irqchip/gic-v3-its: Add support for device tree msi-map and msi-mask

Message ID 20250414-ep-msi-v18-5-f69b49917464@nxp.com
State New
Headers show
Series PCI: EP: Add RC-to-EP doorbell with platform MSI controller | expand

Commit Message

Frank Li April 14, 2025, 6:30 p.m. UTC 
Some platform devices create child devices dynamically and require the
parent device's msi-map to map device IDs to actual sideband information.

A typical use case is using ITS as a PCIe Endpoint Controller(EPC)'s
doorbell function, where PCI hosts send TLP memory writes to the EP
controller. The EP controller converts these writes to AXI transactions
and appends platform-specific sideband information.

EPC's DTS will provide such information by msi-map and msi-mask. A
simplified dts as

pcie-ep@10000000 {
	...
	msi-map = <0 &its 0xc 8>;
                          ^^^ 0xc is implement defined sideband information,
			      which append to AXI write transaction.
	           ^ 0 is function index.

	msi-mask = <0x7>
}

Check msi-map if msi-parent missed to keep compatility with existed system.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change from v15 to v16
- remove ascii figures in commit message

change from v14 to v15
- none

change from v13 to v14
new patch
---
 drivers/irqchip/irq-gic-v3-its-msi-parent.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/drivers/irqchip/irq-gic-v3-its-msi-parent.c b/drivers/irqchip/irq-gic-v3-its-msi-parent.c
index bdb04c8081480..68f9ba4085ce5 100644
--- a/drivers/irqchip/irq-gic-v3-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-v3-its-msi-parent.c
@@ -118,6 +118,14 @@  static int of_pmsi_get_dev_id(struct irq_domain *domain, struct device *dev,
 		index++;
 	} while (!ret);
 
+	if (ret) {
+		struct device_node *np = NULL;
+
+		ret = of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &np, dev_id);
+		if (np)
+			of_node_put(np);
+	}
+
 	return ret;
 }