Before of this change, many specific classes to VirtIO were in the
Kernel namespace, which polluted it.
Everything should be more organized now, but there's still room for
improvement later.
This class member was used only to determine the device type when
printing messages to the debug log. Instead, remove this class member,
and add a quick way to find the device type according to how the VirtIO
specification says to do that.
This simplifies construction of VirtIODevices a bit, because now the
constructor doesn't need to ask for a String identified with the device
type.
Now that the old PCI::Device was removed, we can complete the PCI
changes by making the PCI::DeviceController to be named PCI::Device.
Really the entire purpose and the distinction between the two was about
interrupts, but since this is no longer a problem, just rename it to
simplify things further.
This makes for nicer handling of errors compared to checking whether a
RefPtr is null. Additionally, this will give way to return different
types of errors in the future.
...and also RangeAllocator => VirtualRangeAllocator.
This clarifies that the ranges we're dealing with are *virtual* memory
ranges and not anything else.
Now that all KResult and KResultOr are used consistently throughout the
kernel, it's no longer necessary to return negative error codes.
However, we were still doing that in some places, so let's fix all those
(bugs) by removing the minuses. :^)
This allows us to specify virtual addresses for things the kernel should
access via virtual addresses later on. By doing this we can make the
kernel independent from specific physical addresses.
It's easy to forget the responsibility of validating and safely copying
kernel parameters in code that is far away from syscalls. ioctl's are
one such example, and bugs there are just as dangerous as at the root
syscall level.
To avoid this case, utilize the AK::Userspace<T> template in the ioctl
kernel interface so that implementors have no choice but to properly
validate and copy ioctl pointer arguments.
We don't need to have a dedicated API for creating a VMObject with a
single page, the multi-page API option works in all cases.
Also make the API take a Span<NonnullRefPtr<PhysicalPage>> instead of
a NonnullRefPtrVector<PhysicalPage>.
It is not legal to resize a VMObject after it has been created.
As far as I can tell, this code would never actually run since the
object was already populated with physical pages due to using
AllocationStrategy::AllocateNow.
The spec requires a flush after setting the new buffer resource id,
which is required by QEMUs SDL backend but not the GTK backend. This
brings us in line with the spec and makes it work for the SDL backend.
These functions are only used from within `dbgln_if` calls, so in
certain build configurations, they go unused. Similarly to variables, we
now signal to the compiler that we understand that these are not always
in use.
We were creating a new memory mapping every time WindowServer performed
a buffer flip. This was very visible in whole-system profiles, as the
mapping and unmapping of MMIO registers caused quite a bit of kmalloc()
and kfree() churn.
Avoid this problem by simply keeping the MMIO registers mapped.
Some devices may require DMA transfers to flush the updated buffer
areas prior to flipping. For those devices we track the areas that
require flushing prior to the next flip. For devices that do not
support flipping, but require flushing, we'll simply flush after
updating the front buffer.
This also adds a small optimization that skips these steps entirely for
a screen that doesn't have any updates that need to be rendered.
