pci: Do not reconcile MPS across PCI domainsstable/15

A PCI function can provide a host bridge into a synthetic PCI domain.
Intel VMD does this: the host facing VMD function remains in its
original domain while the hidden Root Ports and endpoints appear in a
separate domain.  The VMD function's Device Control does not describe
an upstream link in that synthetic hierarchy.

The hierarchy wide cold pass incorrectly used the VMD function's MPS
to reprogram the hidden ports and their endpoints.  Stop both cold
reconciliation and runtime path walks at a PCI domain boundary.  The
real Root Ports within the VMD domain continue to reconcile their
endpoints normally.

Reviewed by:	imp
Tested by:	Michael Butler <imb@protected-networks.net>
Fixes:		8e9fe9996a1f ("pci: Reconcile MPS before attaching PCIe devices")
Sponsored by:	BBOX.io
Differential Revision:	https://reviews.freebsd.org/D58837

(cherry picked from commit 57293f4541cdea8e4158f751a4439f69b3ec1711)

0 files changed, 0 insertions, 0 deletions