fdt: Delete nodes of devices removed between boot and CAS

We recently fixed node creation at CAS in order to support early hotplug
of devices between boot and CAS. Let's handle node removal now to support
early hot *un*plug of devices.

This is achieved by associating a generation number to each FDT received
from QEMU and tagging all nodes with this number in a "slof,from-fdt"
property. The generation number is kept in the fdt-generation# variable.
It starts at 0 for the initial boot time FDT, and it is incremented at
each subsequent CAS. All boot time nodes hence get "slof,from-fdt" == 0,
all nodes present at CAS get "slof,from-fdt" == 1 and so on in case the
guest calls CAS again. If a device gets hot unplugged before quiesce, we
hence can detect it doesn't have the right generation number and thus
delete the node from the DT. Note that this only affects nodes coming
from the FDT. Nodes created by SLOF don't have the "slof,from-fdt"
property, and therefore cannot be candidates to deletion.

Signed-off-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

0 files changed, 0 insertions, 0 deletions