acpi_pcihp_get_bsel implements functionality of object_property_get_int for
specific property named ACPI_PCIHP_PROP_BSEL, but fails to decrement object's
reference counter properly. Rewriting it using generic object_property_get_int
serves two purposes: reducing code duplication and fixing memory leak.
Signed-off-by: NKirill Batuzov <batuzovk@ispras.ru>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Split piix4_device_hotplug() into hotplug/unplug callbacks
and register them as "hotplug-handler" interface implementation of
PIIX4_PM device.

Replace pci_bus_hotplug() wiring with setting link on
PCI BUS "hotplug-handler" property to PIIX4_PM device.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Get rid of PCIDevice specific PCIDeviceClass.no_hotplug and use
generic DeviceClass.hotpluggable field instead.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

reduces acpi PCI hotplug code duplication by ~200LOC
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

due to recent change introduced by:
"pcihp: reduce number of device check events"

'up' field is cleared right after it's read.
This is incompatible with legacy BIOS ACPI code
where PCNF ACPI method reads this field 32 times.

To make pci_read mmio callback compatible with legacy
'up' behavior, pcihp code will need to know in which
mode it runs add 'legacy_piix' field to AcpiPciHpState
structure and alter register behavior accordingly.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

... removes dependency of mmio handler on PCI_HOTPLUG_ADDR.
It will be needed in case of Q35 where base could be different.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

enable_device() and disable_device() functions aren't reused anywere,
so replace them with respective oneliners at call sites.
Signed-off-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

PIIX created a made-up value for the UP register since it was read by
guest 32 times for each interrupt.
There's no reason to do this for the new PCIHP: register is only read
once for each interrupt, so clean up code by making read act as an
interrupt acknowledgement: the new UP register clear on read.

In this way we cut down the number of bus rescans
by a factor of 32, and drop a bunch of code that's
now unused.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

Add ACPI based PCI hotplug library with bridge hotplug
support.
Design
   - each bus gets assigned "bsel" property.
   - ACPI code writes this number
     to a new BNUM register, then uses existing
     UP/DOWN registers to probe slot status;
     to eject, write number to BNUM register,
     then slot into existing EJ.

The interface is actually backwards-compatible with
existing PIIX4 ACPI (though not migration compatible).

This is split out from PIIX4 codebase so we can
reuse it for Q35 as well.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>