commit f652e7d2916fe2fcf9e7d709aa5b7476b431e2dd upstream.

When we have an SHPC-capable bridge with a second SHPC-capable bridge
below it, pushing the upstream bridge's attention button causes a
deadlock.

The deadlock happens because we use the shpchp_wq workqueue to run
shpchp_pushbutton_thread(), which uses shpchp_disable_slot() to remove
devices below the upstream bridge.  When we remove the downstream bridge,
we call shpc_remove(), the shpchp driver's .remove() method.  That calls
flush_workqueue(shpchp_wq), which deadlocks because the
shpchp_pushbutton_thread() work item is still running.

This patch avoids the deadlock by creating a workqueue for every slot
and removing the single shared workqueue.

Here's the call path that leads to the deadlock:

  shpchp_queue_pushbutton_work
    queue_work(shpchp_wq)		# shpchp_pushbutton_thread
    ...

  shpchp_pushbutton_thread
    shpchp_disable_slot
      remove_board
        shpchp_unconfigure_device
          pci_stop_and_remove_bus_device
            ...
              shpc_remove		# shpchp driver .remove method
                hpc_release_ctlr
                  cleanup_slots
                    flush_workqueue(shpchp_wq)

This change is based on code inspection, since we don't have hardware
with this topology.

Based-on-patch-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d347e75847c1fb299c97736638f45e6ea39702d4 upstream.

Use non-ordered workqueue for attention button events.

Attention button events on each slot can be handled asynchronously. So
we should use non-ordered workqueue. This patch also removes ordered
workqueue in shpchp as a result.

486b10b9f4 ("PCI: pciehp: Handle push button event asynchronously") made
the same change to pciehp.  I split this out from a patch by Yijing Wang
<wangyijing@huawei.com> so we fix one thing at a time and to make the
shpchp history correspond more closely with the pciehp history.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c2be6f93b383c873a4f9d521afa49b1b67d06085 upstream.

When we have a hotplug-capable PCIe port with a second hotplug-capable
PCIe port below it, removing the device below the upstream port causes
a deadlock.

The deadlock happens because we use the pciehp_wq workqueue to run
pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices
below the upstream port.  When we remove the downstream PCIe port, we call
pciehp_remove(), the pciehp driver's .remove() method.  That calls
flush_workqueue(pciehp_wq), which deadlocks because the
pciehp_power_thread() work item is still running.

This patch avoids the deadlock by creating a workqueue for every PCIe port
and removing the single shared workqueue.

Here's the call path that leads to the deadlock:

  pciehp_queue_pushbutton_work
    queue_work(pciehp_wq)                   # queue pciehp_power_thread
    ...

  pciehp_power_thread
    pciehp_disable_slot
      remove_board
	pciehp_unconfigure_device
	  pci_stop_and_remove_bus_device
	    ...
	      pciehp_remove                 # pciehp driver .remove method
		pciehp_release_ctrl
		  pcie_cleanup_slot
		    flush_workqueue(pciehp_wq)

This is fairly urgent because it can be caused by simply unplugging a
Thunderbolt adapter, as reported by Daniel below.

[bhelgaas: changelog]
Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com
Reported-and-tested-by: Daniel J Blueman <daniel@quora.org>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull powerpc updates from Benjamin Herrenschmidt:
 "Some highlights in addition to the usual batch of fixes:

   - 64TB address space support for 64-bit processes by Aneesh Kumar

   - Gavin Shan did a major cleanup & re-organization of our EEH support
     code (IBM fancy PCI error handling & recovery infrastructure) which
     paves the way for supporting different platform backends, along
     with some rework of the PCIe code for the PowerNV platform in order
     to remove home made resource allocations and instead use the
     generic code (which is possible after some small improvements to it
     done by Gavin).

   - Uprobes support by Ananth N Mavinakayanahalli

   - A pile of embedded updates from Freescale folks, including new SoC
     and board supports, more KVM stuff including preparing for 64-bit
     BookE KVM support, ePAPR 1.1 updates, etc..."

Fixup trivial conflicts in drivers/scsi/ipr.c

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits)
  powerpc/iommu: Fix multiple issues with IOMMU pools code
  powerpc: Fix VMX fix for memcpy case
  driver/mtd:IFC NAND:Initialise internal SRAM before any write
  powerpc/fsl-pci: use 'Header Type' to identify PCIE mode
  powerpc/eeh: Don't release eeh_mutex in eeh_phb_pe_get
  powerpc: Remove tlb batching hack for nighthawk
  powerpc: Set paca->data_offset = 0 for boot cpu
  powerpc/perf: Sample only if SIAR-Valid bit is set in P7+
  powerpc/fsl-pci: fix warning when CONFIG_SWIOTLB is disabled
  powerpc/mpc85xx: Update interrupt handling for IFC controller
  powerpc/85xx: Enable USB support in p1023rds_defconfig
  powerpc/smp: Do not disable IPI interrupts during suspend
  powerpc/eeh: Fix crash on converting OF node to edev
  powerpc/eeh: Lock module while handling EEH event
  powerpc/kprobe: Don't emulate store when kprobe stwu r1
  powerpc/kprobe: Complete kprobe and migrate exception frame
  powerpc/kprobe: Introduce a new thread flag
  powerpc: Remove unused __get_user64() and __put_user64()
  powerpc/eeh: Global mutex to protect PE tree
  powerpc/eeh: Remove EEH PE for normal PCI hotplug
  ...

Commit 0d52f54e2ef64c189dedc332e680b2eb4a34590a (PCI / ACPI: Make acpiphp
ignore root bridges using PCIe native hotplug) added code that made the
acpiphp driver completely ignore PCIe root complexes for which the kernel
had been granted control of the native PCIe hotplug feature by the BIOS
through _OSC. Later commit 619a5182d1f38a3d629ee48e04fa182ef9170052
"PCI hotplug: Always allow acpiphp to handle non-PCIe bridges" relaxed
the constraints to allow acpiphp driver handle non-PCIe bridges under
such a complex.  The constraint needs to be relaxed further to allow
acpiphp driver to handle PCIe ports without native PCIe hotplug capability.

Some MR-IOV switch chipsets, such PLX8696, support multiple virtual PCIe
switches and may migrate downstream ports among virtual switches.  To
migrate a downstream port from the source virtual switch to the target, the
port needs to be hot-removed from the source and hot-added into the target.
The pciehp driver can't be used here because there are no slots within the
virtual PCIe switch.  So acpiphp driver is used to support downstream port
migration.  A typical configuration is as below:

    [Root without native PCIe HP]
        [Upstream port of vswitch without native PCIe HP]
            [Downstream port of vswitch with native PCIe HP]
                [PCIe endpoint]

Here acpiphp driver will be used to handle root ports and upstream port
in the virtual switch, and pciehp driver will be used to handle downstream
ports in the virtual switch.

Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>

This patch changes .add/.remove interfaces of acpi_pci_driver.
In the current implementation acpi_handle is passed as a parameter
of .add/.remove interface.  However, the acpi_pci_root structure
contains more useful information than just the acpi_handle.  This
enables us to avoid some useless lookups in each acpi_pci_driver.

Note: This changes interfaces used by acpi_pci_register_driver(), an
exported symbol.  This patch updates all the in-kernel users, but any
out-of-kernel acpi_pci_register_driver() users will need updates.

[bhelgaas: changelog]
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Function eeh_rmv_from_parent_pe() could be called by the path of
either normal PCI hotplug, or EEH recovery. For the former case,
we need purge the corresponding PE on removal of the associated
PE bus.

The patch tries to cover that by passing more information to function
pcibios_remove_pci_devices() so that we know if the corresponding PE
needs to be purged or be marked as "invalid".

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

* pci/jiang-get-domain-bus-slot:
  xen-pcifront: Use hotplug-safe pci_get_domain_bus_and_slot()
  PCI: Use hotplug-safe pci_get_domain_bus_and_slot()
  PCI/cpcihp: Use hotplug-safe pci_get_domain_bus_and_slot()
  PCI/vga: Use hotplug-safe pci_get_domain_bus_and_slot()
  ia64/PCI: Use hotplug-safe pci_get_domain_bus_and_slot()