Kernel: Rework AML namespace and object hierarchy

Remove tree-like structure from AML. This allows more spec compliant
parsing of named objects inside not yet declared devices.

This also allows AML to be run thread safely. All object adds/removes
are now guarded by a mutex.

kernel/include/kernel/ACPI/AML/Device.h

@@ -42,11 +42,13 @@ namespace Kernel::ACPI::AML
 			AML_DEBUG_PRINT("Device ");
 			name.debug_print();
 			AML_DEBUG_PRINTLN(" {");
-			for (const auto& [name, object] : objects)
-			{
-				object->debug_print(indent + 1);
-				AML_DEBUG_PRINTLN("");
-			}
+			Namespace::root_namespace()->for_each_child(scope,
+				[&](const auto&, const auto& child)
+				{
+					child->debug_print(indent + 1);
+					AML_DEBUG_PRINTLN("");
+				}
+			);
 			AML_DEBUG_PRINT_INDENT(indent);
 			AML_DEBUG_PRINT("}");
 		}

kernel/include/kernel/ACPI/AML/Method.h

@@ -59,7 +59,7 @@ namespace Kernel::ACPI::AML
 			if (!method_scope.has_value())
 				return ParseResult::Failure;
 			method->term_list = method_pkg.value();
-			method->scope = method_scope.release_value();
+			method->scope = AML::NameString(method_scope.release_value());
 
 #if AML_DEBUG_LEVEL >= 2
 			method->debug_print(0);

kernel/include/kernel/ACPI/AML/Names.h

@@ -36,6 +36,14 @@ namespace Kernel::ACPI::AML
 			aml_data = aml_data.slice(4);
 		}
 
+		BAN::StringView sv() const
+		{
+			size_t len = 4;
+			while (len > 0 && chars[len - 1] == '_')
+				len--;
+			return BAN::StringView(chars, len);
+		}
+
 		static BAN::Optional<NameSeg> parse(BAN::ConstByteSpan& aml_data)
 		{
 			if (aml_data.size() < 4)

kernel/include/kernel/ACPI/AML/Namespace.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <BAN/HashMap.h>
 #include <kernel/ACPI/AML/Scope.h>
 #include <kernel/ACPI/Headers.h>
 #include <kernel/Lock/Mutex.h>
@@ -11,12 +12,34 @@ namespace Kernel::ACPI::AML
 	{
 		static BAN::RefPtr<AML::Namespace> root_namespace();
 
+		template<typename F>
+		static void for_each_child(const AML::NameString& scope, const F& callback)
+		{
+			auto canonical_path = root_namespace()->resolve_path({}, scope);
+			ASSERT(canonical_path.has_value());
+
+			for (auto& [path, child] : root_namespace()->m_objects)
+			{
+				if (path.size() < canonical_path->size() + 1)
+					continue;
+				if (path[canonical_path->size()] != '.')
+					continue;
+				if (path.sv().substring(0, canonical_path->size()) != canonical_path->sv())
+					continue;
+				if (path.sv().substring(canonical_path->size() + 1).contains('.'))
+					continue;
+				callback(path, child);
+			}
+		}
+
 		Namespace(NameSeg name) : AML::Scope(Node::Type::Namespace, name) {}
 
 		static BAN::RefPtr<AML::Namespace> create_root_namespace();
 		bool parse(const SDTHeader& header);
 
-		BAN::Optional<AML::NameString> resolve_path(const AML::NameString& relative_base, const AML::NameString& relative_path);
+		void debug_print(int indent) const override;
+
+		BAN::Optional<BAN::String> resolve_path(const AML::NameString& relative_base, const AML::NameString& relative_path, bool allow_nonexistent = false);
 
 		// Find an object in the namespace. Returns nullptr if the object is not found.
 		BAN::RefPtr<NamedObject> find_object(const AML::NameString& relative_base, const AML::NameString& relative_path);
@@ -26,6 +49,10 @@ namespace Kernel::ACPI::AML
 
 		// Remove an object from the namespace. Returns false if the object could not be removed.
 		bool remove_named_object(const AML::NameString& absolute_path);
+
+	private:
+		BAN::HashMap<BAN::String, BAN::RefPtr<NamedObject>> m_objects;
+		mutable Mutex m_object_mutex;
 	};
 
 }

kernel/include/kernel/ACPI/AML/Scope.h

@@ -1,6 +1,5 @@
 #pragma once
 
-#include <BAN/HashMap.h>
 #include <kernel/ACPI/AML/NamedObject.h>
 #include <kernel/ACPI/AML/Names.h>
 
@@ -9,7 +8,6 @@ namespace Kernel::ACPI::AML
 
 	struct Scope : public AML::NamedObject
 	{
-		BAN::HashMap<NameSeg, BAN::RefPtr<NamedObject>> objects;
 		AML::NameString scope;
 
 		Scope(Node::Type type, NameSeg name)
@@ -19,7 +17,6 @@ namespace Kernel::ACPI::AML
 		virtual bool is_scope() const override { return true; }
 
 		static ParseResult parse(ParseContext& context);
-		virtual void debug_print(int indent) const override;
 
 	protected:
 		ParseResult enter_context_and_parse_term_list(ParseContext& outer_context, const AML::NameString& name, BAN::ConstByteSpan aml_data);