tree 040113ba2adcb26dc8a1370c08eec95d6c699c0c
parent f808873372381a401dcd86d7d45a5ee6fd164d50
author Boyan Karatotev <boyan.karatotev@arm.com> 1733132170 +0000
committer Boyan Karatotev <boyan.karatotev@arm.com> 1734362070 +0000

fix(trbe): add a tsb before context switching

Just like for SPE, we need to synchronize TRBE samples before we change
the context to ensure everything goes where it was intended to. If that
is not done, the in-flight entries might use any piece of now incorrect
context as there are no implicit ordering requirements.

Prior to root context, the buffer drain hooks would have done that. But
now that must happen much earlier. So add a tsb to prepare_el3_entry as
well.

Annoyingly, the barrier can be reordered relative to other instructions
by default (rule RCKVWP). So add an isb after the psb/tsb to assure that
they are ordered, at least as far as context is concerned.

Then, drop the buffer draining hooks. Everything they need to do is
already done by now. There's a notable difference in that there are no
dsb-s now. Since EL3 does not access the buffers or the feature
specific context, we don't need to wait for them to finish.

Finally, drop a stray isb in the context saving macro. It is now
absorbed into root context, but was missed.

Change-Id: I30797a40ac7f91d0bb71ad271a1597e85092ccd5
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>