arch/arm64/cpu-hotplug.rst

1 .. SPDX-License-Identifier: GPL-2.0
10 CPUs that were not available during boot to be added to the system later.
15 CPU Hotplug on physical systems - CPUs not present at boot
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34 boot to discover the system wide supported features. ACPI's MADT GICC
42 CPU Hotplug on virtual systems - CPUs not enabled at boot
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46 ever have can be described at boot. There are no power-domain considerations
63 that firmware wishes to disable either from boot (or later) should not be
64 ``enabled`` in the MADT GICC structures, but should have the ``online capable``
65 bit set, to indicate they can be enabled later. The boot CPU must be marked as
66 ``enabled``.  The 'always on' GICR structure must be used to describe the
69 CPUs described as ``online capable`` but not ``enabled`` can be set to enabled
72 be notified to the OS via device-check or eject-request.
74 CPUs described as ``enabled`` in the static table, should not have their _STA
75 modified dynamically by firmware. Soft-restart features such as kexec will
76 re-read the static properties of the system from these static tables, and
78 re-discover the dynamic properties of the system from the _STA method later
79 during boot.