From 7c5b59556a559304ed5bb897552b312ff4e99cf9 Mon Sep 17 00:00:00 2001
From: Johannes Schlatow <johannes.schlatow@genode-labs.com>
Date: Fri, 8 Sep 2023 13:28:56 +0200
Subject: [PATCH] pci_decode: add <iommu> node to devices

genodelabs/genode#5002
---
 repos/os/src/app/pci_decode/main.cc | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/repos/os/src/app/pci_decode/main.cc b/repos/os/src/app/pci_decode/main.cc
index 6f4759df73..42c7460529 100644
--- a/repos/os/src/app/pci_decode/main.cc
+++ b/repos/os/src/app/pci_decode/main.cc
@@ -244,6 +244,35 @@ bus_t Main::parse_pci_function(Bdf             bdf,
 					gen.attribute("size",    rmrr.size);
 				});
 		});
+
+		/* XXX We currently only support unsegmented platforms with a single
+		 *     pci config space. Yet as soon as we do support those, we
+		 *     must assign the DMA-remapping hardware unit to the different pci
+		 *     segments resp. their devices.
+		 */
+
+		bool drhd_device_found = false;
+		drhd_list.for_each([&] (Drhd const & drhd) {
+			if (drhd_device_found) return;
+
+			bool device_match = false;
+			drhd.devices.for_each([&] (Drhd::Device const & device) {
+				if (device.bdf == bdf)
+					device_match = true;
+			});
+
+			if (device_match) {
+				drhd_device_found = true;
+				gen.node("io_mmu", [&] { gen.attribute("name", drhd.name()); });
+			}
+		});
+
+		if (!drhd_device_found) {
+			drhd_list.for_each([&] (Drhd const & drhd) {
+				if (drhd.scope == Drhd::Scope::INCLUDE_PCI_ALL)
+					gen.node("io_mmu", [&] { gen.attribute("name", drhd.name()); });
+			});
+		}
 	});
 
 	return subordinate_bus;