PCI: Equalize hotplug memory and io for occupied and empty slots
Currently, a hotplug bridge will be given hpmemsize additional memory
and hpiosize additional io if available, in order to satisfy any future
hotplug allocation requirements.
These calculations don't consider the current memory/io size of the
hotplug bridge/slot, so hotplug bridges/slots which have downstream
devices will be allocated their current allocation in addition to the
hpmemsize value.
This makes for possibly undesirable results with a mix of unoccupied and
occupied slots (ex, with hpmemsize=2M):
02:03.0 PCI bridge: <-- Occupied
Memory behind bridge:
d6200000-
d64fffff [size=3M]
02:04.0 PCI bridge: <-- Unoccupied
Memory behind bridge:
d6500000-
d66fffff [size=2M]
This change considers the current allocation size when using the
hpmemsize/hpiosize parameters to make the reservations predictable for
the mix of unoccupied and occupied slots:
02:03.0 PCI bridge: <-- Occupied
Memory behind bridge:
d6200000-
d63fffff [size=2M]
02:04.0 PCI bridge: <-- Unoccupied
Memory behind bridge:
d6400000-
d65fffff [size=2M]
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>