Instead of doing so in the constructor, let's do immediately after the
constructor, so we can safely pass a reference of a Device, so the
SysFSDeviceComponent constructor can use that object to identify whether
it's a block device or a character device.
This allows to us to not hold a device in SysFSDeviceComponent with a
RefPtr.
Also, we also call the before_removing method in both SlavePTY::unref
and File::unref, so because Device has that method being overrided, it
can ensure the device is removed always cleanly.
This is really a basic support for AHCI hotplug events, so we know how
to add a node representing the device in /sys/dev/block and removing it
according to the event type (insertion/removal).
This change doesn't take into account what happens if the device was
mounted or a read/write operation is being handled.
For this to work correctly, StorageManagement now uses the Singleton
container, as it might be accessed simultaneously from many CPUs
for hotplug events. DiskPartition holds a WeakPtr instead of a RefPtr,
to allow removal of a StorageDevice object from the heap.
StorageDevices are now stored and being referenced to via an
IntrusiveList to make it easier to remove them on hotplug event.
In future changes, all of the stated above might change, but for now,
this commit represents the least amount of changes to make everything
to work correctly.
These methods are no longer needed because SystemServer is able to
populate the DevFS on its own.
Device absolute_path no longer assume a path to the /dev location,
because it really should not assume any path to a Device node.
Because StorageManagement still needs to know the storage name, we
declare a virtual method only for StorageDevices to override, but this
technique should really be removed later on.
A couple of things were changed:
1. Semantic changes - PCI segments are now called PCI domains, to better
match what they are really. It's also the name that Linux gave, and it
seems that Wikipedia also uses this name.
We also remove PCI::ChangeableAddress, because it was used in the past
but now it's no longer being used.
2. There are no WindowedMMIOAccess or MMIOAccess classes anymore, as
they made a bunch of unnecessary complexity. Instead, Windowed access is
removed entirely (this was tested, but never was benchmarked), so we are
left with IO access and memory access options. The memory access option
is essentially mapping the PCI bus (from the chosen PCI domain), to
virtual memory as-is. This means that unless needed, at any time, there
is only one PCI bus being mapped, and this is changed if access to
another PCI bus in the same PCI domain is needed. For now, we don't
support mapping of different PCI buses from different PCI domains at the
same time, because basically it's still a non-issue for most machines
out there.
2. OOM-safety is increased, especially when constructing the Access
object. It means that we pre-allocating any needed resources, and we try
to find PCI domains (if requested to initialize memory access) after we
attempt to construct the Access object, so it's possible to fail at this
point "gracefully".
3. All PCI API functions are now separated into a different header file,
which means only "clients" of the PCI subsystem API will need to include
that header file.
4. Functional changes - we only allow now to enumerate the bus after
a hardware scan. This means that the old method "enumerate_hardware"
is removed, so, when initializing an Access object, the initializing
function must call rescan on it to force it to find devices. This makes
it possible to fail rescan, and also to defer it after construction from
both OOM-safety terms and hotplug capabilities.
This expands the reach of error propagation greatly throughout the
kernel. Sadly, it also exposes the fact that we're allocating (and
doing other fallible things) in constructors all over the place.
This patch doesn't attempt to address that of course. That's work for
our future selves.
The default template argument is only used in one place, and it
looks like it was probably just an oversight. The rest of the Kernel
code all uses u8 as the type. So lets make that the default and remove
the unused template argument, as there doesn't seem to be a reason to
allow the size to be customizable.
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.
...and also RangeAllocator => VirtualRangeAllocator.
This clarifies that the ranges we're dealing with are *virtual* memory
ranges and not anything else.
Problem:
- New `all_of` implementation takes the entire container so the user
does not need to pass explicit begin/end iterators. This is unused
except is in tests.
Solution:
- Make use of the new and more user-friendly version where possible.
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>.
The `#pragma GCC diagnostic` part is needed because the class has
virtual methods with the same name but different arguments, and Clang
tries to warn us that we are not actually overriding anything with
these.
Weirdly enough, GCC does not seem to care.
This fixes a bug that occurs when the controller's ports are not
(internally) numbered sequentially.
This is done by checking the bits set in PI.
This bug was found on bare-metal, on a laptop with 1 Port that
was reported as port 4.
If we are in a shared interrupt handler, the called handlers might
indicate it was not their interrupt, so we should not increment the
call counter of these handlers.
This has a quirk with the AMD Hudson-2 SATA controller. [1022:7801]
Having this flag set makes the controller become stuck in a busy loop.
I decided to remove the flag instead of making it a quirk as it still
works with Qemu, VirtualBox, VMware Player and the Intel Wildcat
Point-LP SATA Controller [8086:9c83] without it, thus making it simpler
to just remove it.
Partial fix for #7738 (as it still does not work in IDE mode)
This change allows the controller to utilize interrupts even if no
device was connected to a port when we initialize it, so we can support
hotplug events now.
This was proved to be a problematic option. I tested this option on
bare metal AHCI controller, and if we didn't reset the controller, the
firmware (SeaBIOS) could leave the controller state not clean, so an
plugged device signature was in place although the specific port had no
plugged device after rebooting.
Therefore, we need to ensure we use the controller in a clean state
always.
In addition to that, the Complete option was renamed to Aggressive, as
it represents better the consequences of choosing this option.
