On 22/07/2020 14:26, Oliver O'Halloran wrote:

The EEH core has a concept of a "PE tree" to support PowerNV. The PE tree
follows the PCI bus structures because a reset asserted on an upstream
bridge will be propagated to the downstream bridges. On pseries there's a
1-1 correspondence between what the guest sees are a PHB and a PE so the
"tree" is really just a single node.

Current the EEH core is reponsible for setting up this PE tree which it
does by traversing the pci_dn tree. The structure of the pci_dn tree
matches the bus tree on PowerNV which leads to the PE tree being "correct"
this setup method doesn't make a whole lot of sense and it's actively
confusing for the pseries case where it doesn't really do anything.

We want to remove the dependence on pci_dn anyway so this patch move
choosing where to insert a new PE into the platform code rather than
being part of the generic EEH code. For PowerNV this simplifies the
tree building logic and removes the use of pci_dn. For pseries we
keep the existing logic. I'm not really convinced it does anything
due to the 1-1 PE-to-PHB correspondence so every device under that
PHB should be in the same PE, but I'd rather not remove it entirely
until we've had a chance to look at it more deeply.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <redacted>
---
v2: Reworked pseries PE setup slightly. NOT DONE YET. mostly done needs test

So far it was looking good and now this :)

When is it going to be done? Is this the broken stuff you mentioned
elsewhere?


-- 
Alexey