RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 04:57:44 +00:00
Code Issues Activity Actions

Kernel/PCI: Don't hold spinlocks when doing fast device enumeration

Browse source 
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.
This commit is contained in:
Liav A 2022-02-04 19:48:13 +02:00 • committed by Andreas Kling
parent c0ed656c94
commit 3fb289e27d
14 changed files with 69 additions and 42 deletions
Download patch file Download diff file Expand all files Collapse all files

4
Kernel/Devices/Audio/Management.cpp
View file

@ -39,7 +39,7 @@ UNMAP_AFTER_INIT AudioManagement::AudioManagement()
UNMAP_AFTER_INIT void AudioManagement::enumerate_hardware_controllers()
{
if (!PCI::Access::is_disabled()) {
PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
MUST(PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
// Note: Only consider PCI audio controllers
if (device_identifier.class_code().value() != to_underlying(PCI::ClassID::Multimedia)
|| device_identifier.subclass_code().value() != to_underlying(PCI::Multimedia::SubclassID::AudioController))
@ -53,7 +53,7 @@ UNMAP_AFTER_INIT void AudioManagement::enumerate_hardware_controllers()
return;
}
m_controllers_list.append(ac97_device.release_value());
});
}));
}
}