Rework pciehp event handling & add runtime PM

Rework pciehp to use modern, threaded IRQ handling. The slot is powered on and off synchronously in the IRQ thread, no indirection via a work queue anymore.

When the slot is enabled/disabled by the user via sysfs or an Attention Button press, a request is sent to the IRQ thread. The IRQ thread is thus the sole entity enabling/disabling the slot.

The IRQ thread can cope with missed events, e.g. if a card is inserted and immediately pulled out before the IRQ thread had a chance to react. It also tolerates an initially unstable link as observed in the wild by Stefan Roese.

Finally, runtime PM support is added. This was the original motivation of the series because runtime suspending hotplug ports is needed to power down Thunderbolt controllers on idle, which saves ~1.5W per controller. Runtime resuming ports takes tenths of milliseconds during which events may be missed, this in turn necessitated the event handling rework.

I've pushed the series to GitHub to ease reviewing/fetching:
https://github.com/l1k/linux/commits/pciehp_runpm_v2

Please review and test.

Thanks,

Lukas

Lukas Wunner (32):
PCI: hotplug: Don't leak pci_slot on registration failure
PCI: pciehp: Fix UAF on unplug
PCI: pciehp: Fix deadlock on unplug
PCI: pciehp: Fix unprotected list iteration in IRQ handler
PCI: pciehp: Drop unnecessary NULL pointer check
PCI: pciehp: Declare pciehp_unconfigure_device() void
PCI: pciehp: Document struct slot and struct controller
genirq: Synchronize only with single thread on free_irq()
PCI: pciehp: Convert to threaded IRQ
PCI: pciehp: Convert to threaded polling
PCI: pciehp: Stop blinking on slot enable failure
PCI: pciehp: Handle events synchronously
PCI: pciehp: Drop slot workqueue
PCI: hotplug: Demidlayer registration with the core
PCI: pciehp: Publish to user space last on probe
PCI: pciehp: Track enable/disable status
PCI: pciehp: Enable/disable exclusively from IRQ thread
PCI: pciehp: Drop enable/disable lock
PCI: pciehp: Declare pciehp_enable/disable_slot() static
PCI: pciehp: Tolerate initially unstable link
PCI: pciehp: Become resilient to missed events
PCI: pciehp: Always enable occupied slot on probe
PCI: pciehp: Avoid slot access during reset
PCI: portdrv: Deduplicate PM callback iterator
PCI: pciehp: Clear spurious events earlier on resume
PCI: pciehp: Obey compulsory command delay after resume
PCI: pciehp: Support interrupts sent from D3hot
PCI: pciehp: Resume to D0 on enable/disable
PCI: pciehp: Resume parent to D0 on config space access
PCI: sysfs: Resume to D0 on function reset
PCI: Whitelist native hotplug ports for runtime D3
PCI: Whitelist Thunderbolt ports for runtime D3

 drivers/pci/hotplug/acpiphp_core.c      |  22 +-
 drivers/pci/hotplug/cpci_hotplug_core.c |  14 +-
 drivers/pci/hotplug/cpqphp_core.c       |  16 +-
 drivers/pci/hotplug/ibmphp_core.c       |  15 +-
 drivers/pci/hotplug/ibmphp_ebda.c       |  20 --
 drivers/pci/hotplug/pci_hotplug_core.c  | 134 +++++++--
 drivers/pci/hotplug/pciehp.h            | 117 ++++++--
 drivers/pci/hotplug/pciehp_core.c       | 104 ++++---
 drivers/pci/hotplug/pciehp_ctrl.c       | 352 ++++++++++--------------
 drivers/pci/hotplug/pciehp_hpc.c        | 261 ++++++++++--------
 drivers/pci/hotplug/pciehp_pci.c        |  42 ++-
 drivers/pci/hotplug/pcihp_skeleton.c    |  16 +-
 drivers/pci/hotplug/pnv_php.c           |   5 +-
 drivers/pci/hotplug/rpaphp_core.c       |   2 +-
 drivers/pci/hotplug/rpaphp_slot.c       |  13 +-
 drivers/pci/hotplug/s390_pci_hpc.c      |  13 +-
 drivers/pci/hotplug/sgi_hotplug.c       |   9 +-
 drivers/pci/hotplug/shpchp_core.c       |  20 +-
 drivers/pci/pci-sysfs.c                 |   2 +
 drivers/pci/pci.c                       |  21 +-
 drivers/pci/pcie/portdrv.h              |   2 +
 drivers/pci/pcie/portdrv_core.c         |  30 +-
 drivers/pci/pcie/portdrv_pci.c          |   2 +
 drivers/platform/x86/asus-wmi.c         |  12 +-
 drivers/platform/x86/eeepc-laptop.c     |  12 +-
 include/linux/pci_hotplug.h             |  15 +-
 kernel/irq/manage.c                     |  21 +-
 27 files changed, 687 insertions(+), 605 deletions(-)

2.17.1