linux-stable.git/drivers/pci/hotplug, branch v3.2.99

PCI: shpchp: Enable bridge bus mastering if MSI is enabled

2017-11-26T13:51:01+00:00

commit 48b79a14505349a29b3e20f03619ada9b33c4b17 upstream.

An SHPC may generate MSIs to notify software about slot or controller
events (SHPC spec r1.0, sec 4.7).  A PCI device can only generate an MSI if
it has bus mastering enabled.

Enable bus mastering if the bridge contains an SHPC that uses MSI for event
notifications.

Signed-off-by: Aleksandr Bezzubikov 
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Marcel Apfelbaum 
Acked-by: Michael S. Tsirkin 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

powerpc/pci/rpadlpar: Fix device reference leaks

2017-03-16T02:18:25+00:00

commit 99e5cde5eae78bef95bfe7c16ccda87fb070149b upstream.

Make sure to drop any device reference taken by vio_find_node() when
adding and removing virtual I/O slots.

Fixes: 5eeb8c63a38f ("[PATCH] PCI Hotplug: rpaphp: Move VIO registration")
Signed-off-by: Johan Hovold 
Signed-off-by: Michael Ellerman 
Signed-off-by: Ben Hutchings

PCI: pciehp: Prevent NULL dereference during probe

2014-12-14T16:23:42+00:00

commit bceee4a97eb58bd0e80e39eff11b506ddd9e7ad3 upstream.

pciehp assumes that dev->subordinate, the struct pci_bus for a bridge's
secondary bus, exists.  But we do not create that bus if we run out of bus
numbers during enumeration.  This leads to a NULL dereference in
init_slot() (and other places).

Change pciehp_probe() to return -ENODEV when no secondary bus is present.

Signed-off-by: Andreas Noever 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Ben Hutchings

PCI: shpchp: Check bridge's secondary (not primary) bus speed

2014-06-09T12:29:12+00:00

commit 93fa9d32670f5592c8e56abc9928fc194e1e72fc upstream.

When a new device is added below a hotplug bridge, the bridge's secondary
bus speed and the device's bus speed must match.  The shpchp driver
previously checked the bridge's *primary* bus speed, not the secondary bus
speed.

This caused hot-add errors like:

  shpchp 0000:00:03.0: Speed of bus ff and adapter 0 mismatch

Check the secondary bus speed instead.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75251
Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: Marcel Apfelbaum 
Signed-off-by: Bjorn Helgaas 
Acked-by: Michael S. Tsirkin 
Signed-off-by: Ben Hutchings

PCI: shpchp: Use per-slot workqueues to avoid deadlock

2013-02-06T04:33:33+00:00

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 
Signed-off-by: Bjorn Helgaas 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

PCI: shpchp: Handle push button event asynchronously

2013-02-06T04:33:33+00:00

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
 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 
CC: Kenji Kaneshige 
Signed-off-by: Ben Hutchings

PCI: pciehp: Use per-slot workqueues to avoid deadlock

2013-02-06T04:33:32+00:00

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
Reviewed-by: Kenji Kaneshige
Signed-off-by: Yijing Wang
Signed-off-by: Bjorn Helgaas
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

PCI: pciehp: Handle push button event asynchronously

2013-02-06T04:33:32+00:00

commit 486b10b9f43500741cd63a878d0ef23cd87fc66d 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 pciehp as a result.

Signed-off-by: Kenji Kaneshige 
Signed-off-by: Jesse Barnes 
Signed-off-by: Ben Hutchings

PCI: pciehp: Fix wrong workqueue cleanup

2013-02-06T04:33:32+00:00

commit 027e8d52abdd44bc00e405af83cd2fbfb96c0824 upstream.

Fix improper workqueue cleanup.

In the current pciehp, pcied_cleanup() calls destroy_workqueue()
before calling pcie_port_service_unregister(). This causes kernel oops
because flush_workqueue() is called in the pcie_port_service_unregister()
code path after the workqueue was destroyed. So pcied_cleanup() must call
pcie_port_service_unregister() first before calling destroy_workqueue().

Signed-off-by: Kenji Kaneshige 
Signed-off-by: Jesse Barnes 
Signed-off-by: Ben Hutchings

PCI: acpiphp: check whether _ADR evaluation succeeded

2012-10-10T02:31:18+00:00

commit dfb117b3e50c52c7b3416db4a4569224b8db80bb upstream.

Check whether we evaluated _ADR successfully.  Previously we ignored
failure, so we would have used garbage data from the stack as the device
and function number.

We return AE_OK so that we ignore only this slot and continue looking
for other slots.

Found by Coverity (CID 113981).

Signed-off-by: Bjorn Helgaas 
Signed-off-by: Ben Hutchings