To do this we also need to get rid of LockRefPtrs in the USB code as
well.
Most of the SysFS nodes are statically generated during boot and are not
mutated afterwards.
The same goes for general device code - once we generate the appropriate
SysFS nodes, we almost never mutate the node pointers afterwards, making
locking unnecessary.
Decompose the current monolithic USBD Pipe interface into several
subclasses, one for each pair of endpoint type & direction. This is to
make it more clear what data and functionality belongs to which Pipe
type, and prevent nonsensical things like trying to execute a control
transfer on a non-control pipe. This is important, because the Pipe
class is the interface by which USB device drivers will interact with
the HCD, so the clearer and more explicit this interface is the better.
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:
- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable
This patch renames the Kernel classes so that they can coexist with
the original AK classes:
- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable
The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
Instead of having two separate implementations of AK::RefCounted, one
for userspace and one for kernelspace, there is now RefCounted and
AtomicRefCounted.
Some other parts of the USB stack may require us to perform a control
transfer. Instead of abusing `friend` to expose the default pipe, let's
just expose it via a function.
This also introduces a new class, `USBConfiguration` that stores a
configuration. The device, when instructed, sets this configuration and
holds a pointer to it so we have a record of what configuration is
currently active.
We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace!
This was a slightly tedious refactoring that took a long time, so it's
not unlikely that some bugs crept in.
Nevertheless, it does pass basic functionality testing, and it's just
real nice to finally see the same pattern in all contexts. :^)
A hub can technically have up to 255 ports, given that bNbrPorts is a
u8 and the DeviceRemovable field is a VLA to support up to 255 ports.
Source: USB 2.0 Specification Section 11.23.2.1
That means this enum is not going to scale well in terms of size.
Replacing it with a raw u8 allows me to remove the two port assumption
and a cast.
This removes Pipes dependency on the UHCIController by introducing a
controller base class. This will be used to implement other controllers
such as OHCI.
Additionally, there can be multiple instances of a UHCI controller.
For example, multiple UHCI instances can be required for systems with
EHCI controllers. EHCI relies on using multiple of either UHCI or OHCI
controllers to drive USB 1.x devices.
This means UHCIController can no longer be a singleton. Multiple
instances of it can now be created and passed to the device and then to
the pipe.
To handle finding and creating these instances, USBManagement has been
introduced. It has the same pattern as the other management classes
such as NetworkManagement.
