platform_drv: don't restrict ownership to session

This is a prerequisite for letting the platform driver acquire control devices.

genodelabs/genode#4761

repos/os/src/drivers/platform/device.cc

@@ -15,12 +15,12 @@
 
 #include <device.h>
 #include <pci.h>
+#include <device_owner.h>
 #include <device_component.h>
-#include <session_component.h>
 
 
-Driver::Device::Owner::Owner(Session_component & session)
-: obj_id(reinterpret_cast<void*>(&session)) {}
+Driver::Device::Owner::Owner(Device_owner & owner)
+: obj_id(reinterpret_cast<void*>(&owner)) {}
 
 
 Driver::Device::Name Driver::Device::name() const { return _name; }
@@ -32,9 +32,9 @@ Driver::Device::Type Driver::Device::type() const { return _type; }
 Driver::Device::Owner Driver::Device::owner() const { return _owner; }
 
 
-void Driver::Device::acquire(Session_component & sc)
+void Driver::Device::acquire(Device_owner & owner)
 {
-	if (!_owner.valid()) _owner = sc;
+	if (!_owner.valid()) _owner = owner;
 
 	_power_domain_list.for_each([&] (Power_domain & p) {
 
@@ -81,19 +81,20 @@ void Driver::Device::acquire(Session_component & sc)
 		}
 	});
 
-	pci_enable(_env, sc.device_pd(), *this);
-	sc.update_devices_rom();
+	owner.enable_device(*this);
+	owner.update_devices_rom();
+
 	_model.device_status_changed();
 }
 
 
-void Driver::Device::release(Session_component & sc)
+void Driver::Device::release(Device_owner & owner)
 {
-	if (!(_owner == sc))
+	if (!(_owner == owner))
 		return;
 
 	if (!_leave_operational) {
-		pci_disable(_env, *this);
+		owner.disable_device(*this);
 
 		_reset_domain_list.for_each([&] (Reset_domain & r)
 		{
@@ -115,7 +116,7 @@ void Driver::Device::release(Session_component & sc)
 	}
 
 	_owner = Owner();
-	sc.update_devices_rom();
+	owner.update_devices_rom();
 	_model.device_status_changed();
 }
 

repos/os/src/drivers/platform/device.h

@@ -28,6 +28,7 @@
 #include <clock.h>
 #include <reset.h>
 #include <power.h>
+#include <device_owner.h>
 
 namespace Driver {
 
@@ -36,7 +37,7 @@ namespace Driver {
 	class  Device;
 	struct Device_reporter;
 	struct Device_model;
-	class  Session_component;
+	struct Device_owner;
 	struct Irq_update_policy;
 	struct Io_mem_update_policy;
 	struct Io_port_update_policy;
@@ -70,7 +71,7 @@ class Driver::Device : private List_model<Device>::Element
 			void * obj_id;
 
 			Owner() : obj_id(nullptr) {}
-			Owner(Session_component & session);
+			Owner(Device_owner & owner);
 
 			bool operator == (Owner const & o) const {
 				return obj_id == o.obj_id; }
@@ -218,8 +219,8 @@ class Driver::Device : private List_model<Device>::Element
 		Type  type()  const;
 		Owner owner() const;
 
-		virtual void acquire(Session_component &);
-		virtual void release(Session_component &);
+		virtual void acquire(Device_owner &);
+		virtual void release(Device_owner &);
 
 		template <typename FN> void for_each_irq(FN const & fn) const
 		{

repos/os/src/drivers/platform/device_owner.h

@@ -0,0 +1,32 @@
+/*
+ * \brief  Platform driver - Device owner abstraction
+ * \author Johannes Schlatow
+ * \date   2023-01-20
+ */
+
+/*
+ * 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.
+ */
+
+#ifndef _SRC__DRIVERS__PLATFORM__DEVICE_OWNER_H_
+#define _SRC__DRIVERS__PLATFORM__DEVICE_OWNER_H_
+
+namespace Driver
+{
+	struct Device;
+	struct Device_owner;
+}
+
+
+struct Driver::Device_owner
+{
+	virtual void enable_device(Device const &)  {};
+	virtual void disable_device(Device const &) {};
+	virtual void update_devices_rom() {};
+	virtual ~Device_owner() { }
+};
+
+#endif /* _SRC__DRIVERS__PLATFORM__DEVICE_OWNER_H_ */

repos/os/src/drivers/platform/session_component.cc

@@ -125,6 +125,18 @@ void Session_component::update_devices_rom()
 }
 
 
+void Session_component::enable_device(Device const & device)
+{
+	pci_enable(_env, device_pd(), device);
+}
+
+
+void Session_component::disable_device(Device const & device)
+{
+	pci_disable(_env, device);
+}
+
+
 Genode::Rom_session_capability Session_component::devices_rom() {
 	return _rom_session.cap(); }
 

repos/os/src/drivers/platform/session_component.h

@@ -26,6 +26,7 @@
 
 #include <device_component.h>
 #include <device_pd.h>
+#include <device_owner.h>
 
 namespace Driver {
 	class Session_component;
@@ -36,6 +37,7 @@ namespace Driver {
 class Driver::Session_component
 :
 	public  Session_object<Platform::Session>,
+	public  Device_owner,
 	private Registry<Driver::Session_component>::Element,
 	private Dynamic_rom_session::Xml_producer
 {
@@ -61,13 +63,19 @@ class Driver::Session_component
 		Device_pd & device_pd();
 
 		bool matches(Device const &) const;
-		void update_devices_rom();
 
 		Ram_quota_guard & ram_quota_guard() { return _ram_quota_guard(); }
 		Cap_quota_guard & cap_quota_guard() { return _cap_quota_guard(); }
 
 		void update_policy(bool info, Policy_version version);
 
+		/**************************
+		 ** Device Owner methods **
+		 **************************/
+
+		void enable_device(Device const &) override;
+		void disable_device(Device const &) override;
+		void update_devices_rom() override;
 
 		/**************************
 		 ** Platform Session API **