pci: hotplug handler reworks

This is a resend with added RB's. @MST please pick up :)

This series reworks some pci hotplug handlers (except for s390, that will require more work but is not required for now).

1. Route all unplug calls via the hotplug handler when called from the unplug_request handler. This will be required to get multi-stage hotplug handlers running, but also makes sense on its own (just like we already did for some CPU/memory hotplug handlers).

2. Introduce some pre_plug handlers where it makes sense already.

3. Call the plug/pre_plug handler also for coldplugged devices. Especially pcihp is special as it overwrites hotplug handlers.

This series will not yet factor out pre_plug/plug/unplug from pci device realize/unrealize functions, this will require more work but this series is also required first to get it running.

In my opinion what needs to be done in the future:
1. Introduce pre_plug/plug/unplug_request/unplug handlers for all PCI buses
2. Move pci realize/unrealize parts to pre_plug/pkug/unplug functions like pci_pre_plug() ...
3. Call the pci pre_plug/plug/unplug handlers from the PCI bus hotplug handler at the right spots
4. Factor more checks from existing plug() handlers out into pre_plug() (e.g. after the call to pci_pre_plug())

v3 -> v4:
- RB's added

v2 -> v3:
- Added "pci: Reuse pci-bridge hotplug handler handlers for pcie-pci-bridge" -- Use one handler callback for pcie and !pcie
- "pci/shpc: perform unplug via the hotplug handler"
-- Use one handler callback for pcie and !pcie
-- Replace error check by an assertion
- Minor description changes.
- Added Rbs

v1 -> v2:
- Added "pci/pcie: rename hotplug handler callbacks"
- Added "pci/shpc: rename hotplug handler callbacks"
- Added "s390x/pci: rename hotplug handler callbacks"
- Dropped "pci/shpc: move hotplug checks to preplug handler" -- We will have to factor out stuff into pre_plug() first as described above
- Renamed and added more details to the "perform unplug via the hotplug handler" patches
- "pci/pcihp: overwrite hotplug handler recursively from the start" -- Perform the overwrite only for cold plugged bridges, to keep the existing behavior

David Hildenbrand (11):
pci/pcie: rename hotplug handler callbacks
pci/shpc: rename hotplug handler callbacks
s390x/pci: rename hotplug handler callbacks
pci/pcie: stop plug/unplug if the slot is locked pci/pcihp: perform check for bus capability in pre_plug handler pci/pcihp: overwrite hotplug handler recursively from the start pci/pcihp: perform unplug via the hotplug handler pci/pcie: perform unplug via the hotplug handler
pci: Reuse pci-bridge hotplug handler handlers for pcie-pci-bridge pci/shpc: perform unplug via the hotplug handler
spapr_pci: perform unplug via the hotplug handler

 hw/acpi/pcihp.c                 | 47 ++++++++++++++++++++++++++++-----
 hw/acpi/piix4.c                 | 39 ++++++++++++++-------------
 hw/pci-bridge/pci_bridge_dev.c  | 31 ++++++++++++++--------
 hw/pci-bridge/pcie_pci_bridge.c | 32 +++-------------------
 hw/pci/pcie.c                   | 46 +++++++++++++++++++++-----------
 hw/pci/pcie_port.c              |  6 +++--
 hw/pci/shpc.c                   | 25 ++++++++++++------
 hw/ppc/spapr_pci.c              | 33 ++++++++++++++---------
 hw/s390x/s390-pci-bus.c         | 12 ++++-----
 include/hw/acpi/pcihp.h         |  5 ++++
 include/hw/pci/pci_bridge.h     |  6 +++++
 include/hw/pci/pcie.h           | 12 ++++++---
 include/hw/pci/shpc.h           | 10 ++++---
 13 files changed, 187 insertions(+), 117 deletions(-)

2.17.2