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[Valentin Haudiquet]

Hello,

I have tested this patchseries on my K3 board. I had to patch U-Boot
SPL and EDK2 with the mentioned DTS changes.

Afterwards, booting the upstream 7.2 kernel with Spacemit patches
(still in mailing list) works but the kernel hangs in initramfs.

I had to add 3 patches to make it work properly, see the series
below.

I believe one of the issues is that the v3 HSM wakes A100 core 8 only 
when Linux onlines CPU 8. The vendor kernel onlines all 16 CPUs
so ESOS starts and RPMI works. Mainline uses only the X100 complex 
(harts 0-7), so CPU 8 is never onlined, core 8 is never woken,
ESOS never runs, and RPMI mailbox transactions time out.
Patch 3/3 wakes core 8 in OpenSBI pre_init so ESOS is available 
regardless of which CPUs Linux uses.

For the other patches, I'm not sure why the issues are not encountered
with the vendor kernel.

I have adapted those patches from the Spacemit OpenSBI 1.6 vendor tree
logic, through a lot of trial and error. I'm not sure I deeply understand
the hardware-specific details at play, so any comments would be appreciated.

Feel free to take this in as part of the patchseries and modify it if needed,
or send review comments and I can also improve them.

Tested-by: Valentin Haudiquet <valentin.haudiquet at canonical.com>