RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 11:18:11 +00:00
Code Issues Activity Actions

Kernel/Devices: Introduce the Device Control Device

Browse source 
This device will assist userspace to manage hotplug events.
A userspace application reads a DeviceEvent entry until the return value
is zero which indicates no events that are queued and waiting for
processing.
Trying to read with a buffer smaller than sizeof(DeviceEvent) results in
EOVERFLOW.
For now, there's no ioctl mechanism for this device but in the future an
acknowledgement mechanism can be implemented via ioctl(2) interface.
This commit is contained in:
Liav A 2021-12-20 11:10:35 +02:00 • committed by Linus Groh
parent b60e19fd34
commit b1ca39411b
7 changed files with 151 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

29
Kernel/Devices/DeviceManagement.cpp
View file

@ -37,6 +37,11 @@ UNMAP_AFTER_INIT void DeviceManagement::attach_null_device(NullDevice const& dev
m_null_device = device;
}
UNMAP_AFTER_INIT void DeviceManagement::attach_device_control_device(DeviceControlDevice const& device)
{
m_device_control_device = device;
}
DeviceManagement& DeviceManagement::the()
{
return *s_the;
@ -52,6 +57,14 @@ Device* DeviceManagement::get_device(MajorNumber major, MinorNumber minor)
});
}
Optional<DeviceEvent> DeviceManagement::dequeue_top_device_event(Badge<DeviceControlDevice>)
{
SpinlockLocker locker(m_event_queue_lock);
if (m_event_queue.is_empty())
return {};
return m_event_queue.dequeue();
}
void DeviceManagement::before_device_removal(Badge<Device>, Device& device)
{
u64 device_id = encoded_device(device.major(), device.minor());
@ -59,6 +72,14 @@ void DeviceManagement::before_device_removal(Badge<Device>, Device& device)
VERIFY(map.contains(device_id));
map.remove(encoded_device(device.major(), device.minor()));
});
{
DeviceEvent event { DeviceEvent::State::Removed, device.is_block_device(), device.major().value(), device.minor().value() };
SpinlockLocker locker(m_event_queue_lock);
m_event_queue.enqueue(event);
}
if (m_device_control_device)
m_device_control_device->evaluate_block_conditions();
}
void DeviceManagement::after_inserting_device(Badge<Device>, Device& device)
@ -75,6 +96,14 @@ void DeviceManagement::after_inserting_device(Badge<Device>, Device& device)
VERIFY_NOT_REACHED();
}
});
{
DeviceEvent event { DeviceEvent::State::Inserted, device.is_block_device(), device.major().value(), device.minor().value() };
SpinlockLocker locker(m_event_queue_lock);
m_event_queue.enqueue(event);
}
if (m_device_control_device)
m_device_control_device->evaluate_block_conditions();
}
void DeviceManagement::for_each(Function<void(Device&)> callback)