MFC 303497,303559,303645: Disable PCI-e hotplug on bridges with power

controllers.

303497:
Add a loader tunable (hw.pci.enable_pcie_hp) to disable PCI-e HotPlug.

Some systems and/or devices (such as riser cards) do not include a
non-compliant implementation of PCI-e HotPlug that can result in devices
not being attached (e.g. the HotPlug code might assume that a card is
being unplugged and will power the slot off and detach it).  This
tunable can be set to 0 to disable support for PCI-e HotPlug ignoring
the incorrect HotPlug state on these slots.

303559:
Try to declare _hw_pci for all sysctl cases needed after r303497.

303645:
Disable PCI hotplug support for slots with power controllers.

After further review of the spec, I do not think the current HotPlug
code handles slots with power controllers correctly.  In particular,
the power state of the slot is to be inferred from other events, not
from examining the state of the power control bit in SLOT_CTL.  For now,
disable PCI hotplug support on such slots.

PR:		211081
Approved by:	re (gjb)

0 files changed, 0 insertions, 0 deletions