This class already has variables named m_lock, and it's also strange
that locals are named with the `m_` prefix. So lets fix that to make
the code more readable.
Found by PVS-Studio.
This is mainly useful when adding an HostController but due to OOM
condition, we abort temporary Vector insertion of a DeviceIdentifier
and then exit the iteration loop to report back the error if occured.
Instead, hold the lock while we copy the contents to a stack-based
Vector then iterate on it without any locking.
Because we rely on heap allocations, we need to propagate errors back
in case of OOM condition, therefore, both PCI::enumerate API function
and PCI::Access::add_host_controller_and_enumerate_attached_devices use
now a ErrorOr<void> return value to propagate errors. OOM Error can only
occur when enumerating the m_device_identifiers vector under a spinlock
and trying to expand the temporary Vector which will be used locklessly
to actually iterate over the PCI::DeviceIdentifiers objects.
If there's no PCI bus, then it's safe to assume that we run on a x86
machine that has an ISA IDE controller in the system. In such case, we
just instantiate a ISAIDEController object that assumes fixed locations
of IDE IO ports.
Function-local `static constexpr` variables can be `constexpr`. This
can reduce memory consumption, binary size, and offer additional
compiler optimizations.
These changes result in a stripped x86_64 kernel binary size reduction
of 592 bytes.
As make<T> is infallible, it really should not be used anywhere in the
Kernel. Instead replace with fallible `new (nothrow)` calls, that will
eventually be error-propagated.
Add polling support to NVMe so that it does not use interrupt to
complete a IO but instead actively polls for completion. This probably
is not very efficient in terms of CPU usage but it does not use
interrupts to complete a IO which is beneficial at the moment as there
is no MSI(X) support and it can reduce the latency of an IO in a very
fast NVMe device.
The NVMeQueue class has been made the base class for NVMeInterruptQueue
and NVMePollQueue. The factory function `NVMeQueue::try_create` will
return the appropriate queue to the controller based on the polling
boot parameter.
The polling mode can be enabled by adding an extra boot parameter:
`nvme_poll`.
This is being used by GUID partitions so the first three dash-delimited
fields of the GUID are stored in little endian order but the last two
fields are stored in big endian order, hence it's a representation which
is mixed.
If we panic the kernel for a storage-related reason, we might as well be
helpful and print out a list of detected storage devices and their
partitions to help with debugging.
Reasons for such a panic include:
- No boot device with the given name found
- No boot device with the given UUID found
- Failing to open the root filesystem after determining a boot device
Before attempting to remove the device while handling an AHCI port
interrupt, check if m_connected_device is even non-null.
This happened during my bare metal run and caused a kernel panic.
There was a bug while calculating the next index in submit_sync_sqe
function. Use the NVMeQueue's class variable m_qdepth instead of the
hardcoded IO_QUEUE_SIZE.
Apologies for the enormous commit, but I don't see a way to split this
up nicely. In the vast majority of cases it's a simple change. A few
extra places can use TRY instead of manual error checking though. :^)
Instead, try to allocate the DMA buffer before trying to construct the
NVMeQueue. This allows us to fail early if we can't allocate the DMA
buffer before allocating and creating the heavier NVMeQueue object.
Only a generic struct definition was present for NVMeSubmission. To
improve type safety and clarity, added an union of NVMeSubmission
structs that are applicable to the command being submitted.
The CAP.TO is 0 based. Even though I don't see that mentioned in the
spec explicitly, all major OSs such as Linux, FreeBSD add 1 to the
CAP.TO while calculating the timeout.
IO::delay was added as a lazy alternative to looping with a timeout
error if the condition was not satisfied. Now that we have the
wait_for_ready function, remove the delay in the reset and start
controller function.
This mostly just moved the problem, as a lot of the callers are not
capable of propagating the errors themselves, but it's a step in the
right direction.
