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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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4
Kernel/Graphics/GraphicsManagement.cpp
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@ -231,14 +231,14 @@ UNMAP_AFTER_INIT bool GraphicsManagement::initialize()
else if (framebuffer_devices_use_bootloader_framebuffer())
dbgln("Forcing use of framebuffer set up by the bootloader");
PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
MUST(PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
// Note: Each graphics controller will try to set its native screen resolution
// upon creation. Later on, if we don't want to have framebuffer devices, a
// framebuffer console will take the control instead.
if (!is_vga_compatible_pci_device(device_identifier) && !is_display_controller_pci_device(device_identifier))
return;
determine_and_initialize_graphics_device(device_identifier);
});
}));
if (!m_console) {
// If no graphics driver was instantiated and we had a bootloader provided