pci_decode: interpret reserved memory from ACPI

We need the information about reserved memory region reports
from the ACPI tables within the platform driver to pre-fill
IOMMU tables with the corresponding mappings. Therefore,
the pci_decode component now parses the information from the
ACPI ROM, and adds "reserved_memory" nodes to all related
devices in the devices report.

Ref genodelabs/genode#4578

repos/os/src/app/pci_decode/main.cc

@@ -19,6 +19,7 @@
 #include <os/reporter.h>
 
 #include <irq.h>
+#include <rmrr.h>
 #include <pci/config.h>
 
 using namespace Genode;
@@ -43,6 +44,7 @@ struct Main
 
 	List_model<Irq_routing>  irq_routing_list  {};
 	List_model<Irq_override> irq_override_list {};
+	List_model<Rmrr>         reserved_memory_list {};
 
 	Constructible<Attached_io_mem_dataspace> pci_config_ds {};
 
@@ -168,6 +170,15 @@ void Main::parse_pci_function(Bdf             bdf,
 
 			gen.attribute("number", irq);
 		});
+
+		reserved_memory_list.for_each([&] (Rmrr & rmrr) {
+			if (rmrr.bdf == bdf)
+				gen.node("reserved_memory", [&]
+				{
+					gen.attribute("address", rmrr.addr);
+					gen.attribute("size",    rmrr.size);
+				});
+		});
 	});
 }
 
@@ -259,6 +270,11 @@ void Main::sys_rom_update()
 		irq_routing_list.update_from_xml(policy, xml);
 	}
 
+	{
+		Rmrr_policy policy(heap);
+		reserved_memory_list.update_from_xml(policy, xml);
+	}
+
 	parse_pci_config_spaces(xml);
 }
 

repos/os/src/app/pci_decode/rmrr.h

@@ -0,0 +1,75 @@
+/*
+ * \brief  Reserved memory region reporting from ACPI information in list models
+ * \author Stefan Kalkowski
+ * \date   2022-09-12
+ */
+
+/*
+ * Copyright (C) 2022 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 Rmrr : List_model<Rmrr>::Element
+{
+	Bdf    bdf;
+	addr_t addr;
+	size_t size;
+
+	Rmrr(Bdf bdf, addr_t addr, size_t size)
+	: bdf(bdf), addr(addr), size(size) {}
+};
+
+
+struct Rmrr_policy : List_model<Rmrr>::Update_policy
+{
+	Heap & heap;
+
+	void destroy_element(Rmrr & rmrr) {
+		destroy(heap, &rmrr); }
+
+	Rmrr & create_element(Xml_node node)
+	{
+		bus_t bus = 0;
+		dev_t dev = 0;
+		func_t fn = 0;
+		addr_t start = node.attribute_value("start", 0UL);
+		addr_t end   = node.attribute_value("end", 0UL);
+
+		node.with_optional_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);
+			});
+		});
+
+		return *(new (heap) Rmrr({bus, dev, fn}, start, (end-start+1)));
+	}
+
+	void update_element(Rmrr &, Xml_node) {}
+
+	static bool element_matches_xml_node(Rmrr const & rmrr,
+	                                     Genode::Xml_node node)
+	{
+		addr_t start = node.attribute_value("start", 0UL);
+		addr_t end   = node.attribute_value("end", 0UL);
+		return rmrr.addr == start &&
+		       rmrr.size == (end-start+1);
+	}
+
+	static bool node_is_element(Genode::Xml_node node) {
+		return node.has_type("rmrr"); }
+
+	Rmrr_policy(Heap & heap) : heap(heap) {}
+};