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

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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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4
Kernel/Bus/PCI/API.cpp
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@ -17,9 +17,9 @@ u8 read8(Address address, PCI::RegisterOffset field) { return Access::the().read
u16 read16(Address address, PCI::RegisterOffset field) { return Access::the().read16_field(address, to_underlying(field)); }
u32 read32(Address address, PCI::RegisterOffset field) { return Access::the().read32_field(address, to_underlying(field)); }
void enumerate(Function<void(DeviceIdentifier const&)> callback)
ErrorOr<void> enumerate(Function<void(DeviceIdentifier const&)> callback)
{
Access::the().fast_enumerate(callback);
return Access::the().fast_enumerate(callback);
}
DeviceIdentifier get_device_identifier(Address address)