From e816020346a304dc703da9ab927b1015068cb2e1 Mon Sep 17 00:00:00 2001
From: Johannes Schlatow <johannes.schlatow@genode-labs.com>
Date: Fri, 18 Aug 2023 16:39:05 +0200
Subject: [PATCH] pci_decode: add intel_iommu devices to devices ROM

genodelabs/genode#5002
---
 repos/os/src/app/pci_decode/drhd.h  | 61 ++++++++++++++++++++++++++
 repos/os/src/app/pci_decode/main.cc | 66 +++++++++++++++++++++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 repos/os/src/app/pci_decode/drhd.h

diff --git a/repos/os/src/app/pci_decode/drhd.h b/repos/os/src/app/pci_decode/drhd.h
new file mode 100644
index 0000000000..6592687f1e
--- /dev/null
+++ b/repos/os/src/app/pci_decode/drhd.h
@@ -0,0 +1,61 @@
+/*
+ * \brief  DMA remapping hardware reporting from ACPI information in list models
+ * \author Johannes Schlatow
+ * \date   2023-08-14
+ */
+
+/*
+ * Copyright (C) 2023 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+
+#include <base/heap.h>
+#include <pci/types.h>
+#include <util/list_model.h>
+
+using namespace Genode;
+using namespace Pci;
+
+
+struct Drhd : List_model<Drhd>::Element
+{
+	using Drhd_name = String<16>;
+
+	enum Scope { INCLUDE_PCI_ALL, EXPLICIT };
+
+	addr_t   addr;
+	size_t   size;
+	unsigned segment;
+	Scope    scope;
+	unsigned number;
+
+	struct Device : Registry<Device>::Element
+	{
+		Bdf bdf;
+
+		Device(Registry<Device> & registry, Bdf bdf)
+		: Registry<Device>::Element(registry, *this), bdf(bdf)
+		{ }
+	};
+
+	Registry<Device> devices { };
+
+	Drhd(addr_t addr, size_t size, unsigned segment, Scope scope, unsigned number)
+	: addr(addr), size(size), segment(segment), scope(scope), number(number)
+	{ }
+
+	Drhd_name name() const { return Drhd_name("drhd", number); }
+
+	bool matches(Xml_node const &node) const
+	{
+		return addr == node.attribute_value("phys", 0UL);
+	}
+
+	static bool type_matches(Xml_node const &node)
+	{
+		return node.has_type("drhd");
+	}
+};
diff --git a/repos/os/src/app/pci_decode/main.cc b/repos/os/src/app/pci_decode/main.cc
index e250963955..6f4759df73 100644
--- a/repos/os/src/app/pci_decode/main.cc
+++ b/repos/os/src/app/pci_decode/main.cc
@@ -21,6 +21,7 @@
 
 #include <irq.h>
 #include <rmrr.h>
+#include <drhd.h>
 #include <pci/config.h>
 
 using namespace Genode;
@@ -41,6 +42,7 @@ struct Main
 	List_model<Irq_routing>  irq_routing_list  {};
 	List_model<Irq_override> irq_override_list {};
 	List_model<Rmrr>         reserved_memory_list {};
+	List_model<Drhd>         drhd_list {};
 
 	Constructible<Attached_io_mem_dataspace> pci_config_ds {};
 
@@ -412,6 +414,20 @@ void Main::parse_acpi_device_info(Xml_node const &xml, Xml_generator & gen)
 	 */
 	if (xml.has_sub_node("sci_int"))
 		parse_acpica_info(xml, gen);
+
+	/* Intel DMA-remapping hardware units */
+	drhd_list.for_each([&] (Drhd const & drhd) {
+		gen.node("device", [&]
+		{
+			gen.attribute("name", drhd.name());
+			gen.attribute("type", "intel_iommu");
+			gen.node("io_mem", [&]
+			{
+				gen.attribute("address", String<20>(Hex(drhd.addr)));
+				gen.attribute("size",    String<20>(Hex(drhd.size)));
+			});
+		});
+	});
 }
 
 
@@ -559,6 +575,56 @@ Main::Main(Env & env) : env(env)
 		[&] (Rmrr &, Xml_node const &) { }
 	);
 
+	unsigned nbr { 0 };
+	drhd_list.update_from_xml(xml,
+
+		/* create */
+		[&] (Xml_node const &node) -> Drhd &
+		{
+			addr_t   addr  = node.attribute_value("phys", 0UL);
+			size_t   size  = node.attribute_value("size", 0UL);
+			unsigned seg   = node.attribute_value("segment", 0U);
+			unsigned flags = node.attribute_value("flags", 0U);
+
+			Drhd * drhd;
+			if (flags & 0x1)
+				drhd = new (heap) Drhd(addr, size, seg,
+				                       Drhd::Scope::INCLUDE_PCI_ALL, nbr++);
+			else
+				drhd = new (heap) Drhd(addr, size, seg,
+				                       Drhd::Scope::EXPLICIT, nbr++);
+
+			/* parse device scopes which define the explicitly assigned devices */
+			bus_t bus = 0;
+			dev_t dev = 0;
+			func_t fn = 0;
+
+			node.for_each_sub_node("scope", [&] (Xml_node node) {
+				bus = node.attribute_value<uint8_t>("bus_start", 0U);
+				node.with_optional_sub_node("path", [&] (Xml_node node) {
+					dev = node.attribute_value<uint8_t>("dev", 0);
+					fn  = node.attribute_value<uint8_t>("func", 0);
+				});
+
+				new (heap) Drhd::Device(drhd->devices, {bus, dev, fn});
+			});
+
+			return *drhd;
+		},
+
+		/* destroy */
+		[&] (Drhd &drhd)
+		{
+			drhd.devices.for_each([&] (Drhd::Device & device) {
+				destroy(heap, &device); });
+			destroy(heap, &drhd);
+		},
+
+		/* update */
+		[&] (Drhd &, Xml_node const &) { }
+
+	);
+
 	pci_reporter.generate([&] (Xml_generator & generator)
 	{
 		parse_acpi_device_info(xml, generator);