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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
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8
Kernel/Storage/StorageManagement.cpp
View file

@ -53,7 +53,7 @@ UNMAP_AFTER_INIT void StorageManagement::enumerate_pci_controllers(bool force_pi
using SubclassID = PCI::MassStorage::SubclassID;
if (!kernel_command_line().disable_physical_storage()) {
PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
MUST(PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
if (device_identifier.class_code().value() != to_underlying(PCI::ClassID::MassStorage)) {
return;
}
@ -62,7 +62,7 @@ UNMAP_AFTER_INIT void StorageManagement::enumerate_pci_controllers(bool force_pi
constexpr PCI::HardwareID vmd_device = { 0x8086, 0x9a0b };
if (device_identifier.hardware_id() == vmd_device) {
auto controller = PCI::VolumeManagementDevice::must_create(device_identifier);
PCI::Access::the().add_host_controller_and_enumerate_attached_devices(move(controller), [this, nvme_poll](PCI::DeviceIdentifier const& device_identifier) -> void {
MUST(PCI::Access::the().add_host_controller_and_enumerate_attached_devices(move(controller), [this, nvme_poll](PCI::DeviceIdentifier const& device_identifier) -> void {
auto subclass_code = static_cast<SubclassID>(device_identifier.subclass_code().value());
if (subclass_code == SubclassID::NVMeController) {
auto controller = NVMeController::try_initialize(device_identifier, nvme_poll);
@ -72,7 +72,7 @@ UNMAP_AFTER_INIT void StorageManagement::enumerate_pci_controllers(bool force_pi
m_controllers.append(controller.release_value());
}
}
});
}));
}
}
@ -93,7 +93,7 @@ UNMAP_AFTER_INIT void StorageManagement::enumerate_pci_controllers(bool force_pi
m_controllers.append(controller.release_value());
}
}
});
}));
}
}