linux-toradex.git/drivers/pci, branch v3.10.19

PCI / ACPI / PM: Clear pme_poll for devices in D3cold on wakeup

2013-10-01T16:17:45+00:00

commit 834145156bedadfb50121f0bc5e9d9f9f942bcca upstream.

Commit 448bd85 (PCI/PM: add PCIe runtime D3cold support) added a
piece of code to pci_acpi_wake_dev() causing that function to behave
in a special way for devices in D3cold (so that their configuration
registers are not accessed before those devices are resumed).
However, it didn't take the clearing of the pme_poll flag into
account.  That has to be done for all devices, even if they are in
D3cold, or pci_pme_list_scan() will not know that wakeup has been
signaled for the device and will poll its PME Status bit
unnecessarily.

Fix the problem by moving the clearing of the pme_poll flag in
pci_acpi_wake_dev() before the code introduced by commit 448bd85.

Reported-and-tested-by: David E. Box 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

ACPI: Try harder to resolve _ADR collisions for bridges

2013-08-29T16:47:29+00:00

commit 60f75b8e97daf4a39790a20d962cb861b9220af5 upstream.

In theory, under a given ACPI namespace node there should be only
one child device object with _ADR whose value matches a given bus
address exactly.  In practice, however, there are systems in which
multiple child device objects under a given parent have _ADR matching
exactly the same address.  In those cases we use _STA to determine
which of the multiple matching devices is enabled, since some systems
are known to indicate which ACPI device object to associate with the
given physical (usually PCI) device this way.

Unfortunately, as it turns out, there are systems in which many
device objects under the same parent have _ADR matching exactly the
same bus address and none of them has _STA, in which case they all
should be regarded as enabled according to the spec.  Still, if
those device objects are supposed to represent bridges (e.g. this
is the case for device objects corresponding to PCIe ports), we can
try harder and skip the ones that have no child device objects in the
ACPI namespace.  With luck, we can avoid using device objects that we
are not expected to use this way.

Although this only works for bridges whose children also have ACPI
namespace representation, it is sufficient to address graphics
adapter detection issues on some systems, so rework the code finding
a matching device ACPI handle for a given bus address to implement
this idea.

Introduce a new function, acpi_find_child(), taking three arguments:
the ACPI handle of the device's parent, a bus address suitable for
the device's bus type and a bool indicating if the device is a
bridge and make it work as outlined above.  Reimplement the function
currently used for this purpose, acpi_get_child(), as a call to
acpi_find_child() with the last argument set to 'false' and make
the PCI subsystem use acpi_find_child() with the bridge information
passed as the last argument to it.  [Lan Tianyu notices that it is
not sufficient to use pci_is_bridge() for that, because the device's
subordinate pointer hasn't been set yet at this point, so use
hdr_type instead.]

This change fixes a regression introduced inadvertently by commit
33f767d (ACPI: Rework acpi_get_child() to be more efficient) which
overlooked the fact that for acpi_walk_namespace() "post-order" means
"after all children have been visited" rather than "on the way back",
so for device objects without children and for namespace walks of
depth 1, as in the acpi_get_child() case, the "post-order" callbacks
ordering is actually the same as the ordering of "pre-order" ones.
Since that commit changed the namespace walk in acpi_get_child() to
terminate after finding the first matching object instead of going
through all of them and returning the last one, it effectively
changed the result returned by that function in some rare cases and
that led to problems (the switch from a "pre-order" to a "post-order"
callback was supposed to prevent that from happening, but it was
ineffective).

As it turns out, the systems where the change made by commit
33f767d actually matters are those where there are multiple ACPI
device objects representing the same PCIe port (which effectively
is a bridge).  Moreover, only one of them, and the one we are
expected to use, has child device objects in the ACPI namespace,
so the regression can be addressed as described above.

References: https://bugzilla.kernel.org/show_bug.cgi?id=60561
Reported-by: Peter Wu 
Tested-by: Vladimir Lalov 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Bjorn Helgaas 
Cc: Peter Wu 
Signed-off-by: Greg Kroah-Hartman

PCI: Retry allocation of only the resource type that failed

2013-08-12T01:35:24+00:00

commit aa914f5ec25e4371ba18b312971314be1b9b1076 upstream.

Ben Herrenschmidt reported the following problem:

  - The bus has space for all desired MMIO resources, including optional
    space for SR-IOV devices
  - We attempt to allocate I/O port space, but it fails because the bus
    has no I/O space
  - Because of the I/O allocation failure, we retry MMIO allocation,
    requesting only the required space, without the optional SR-IOV space

This means we don't allocate the optional SR-IOV space, even though we
could.

This is related to 0c5be0cb0e ("PCI: Retry on IORESOURCE_IO type
allocations").

This patch changes how we handle allocation failures.  We will now retry
allocation of only the resource type that failed.  If MMIO allocation
fails, we'll retry only MMIO allocation.  If I/O port allocation fails,
we'll retry only I/O port allocation.

[bhelgaas: changelog]
Reference: https://lkml.kernel.org/r/1367712653.11982.19.camel@pasglop
Reported-by: Benjamin Herrenschmidt 
Tested-by: Gavin Shan 
Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device

2013-08-12T01:35:24+00:00

commit 29ed1f29b68a8395d5679b3c4e38352b617b3236 upstream.

Hot-removing a device with SR-IOV enabled causes a null pointer dereference
in v3.9 and v3.10.

This is a regression caused by ba518e3c17 ("PCI: pciehp: Iterate over all
devices in slot, not functions 0-7").  When we iterate over the
bus->devices list, we first remove the PF, which also removes all the VFs
from the list.  Then the list iterator blows up because more than just the
current entry was removed from the list.

ac205b7bb7 ("PCI: make sriov work with hotplug remove") works around a
similar problem in pci_stop_bus_devices() by iterating over the list in
reverse, so the VFs are stopped and removed from the list first, before the
PF.

This patch changes pciehp_unconfigure_device() to iterate over the list in
reverse, too.

[bhelgaas: bugzilla, changelog]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60604
Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas 
Acked-by: Yijing Wang 
Signed-off-by: Greg Kroah-Hartman

ahci: Add AMD CZ SATA device ID

2013-07-22T01:21:30+00:00

commit fafe5c3d82a470d73de53e6b08eb4e28d974d895 upstream.

To add AMD CZ SATA controller device ID of IDE mode.

[bhelgaas: drop pci_ids.h update]
Signed-off-by: Shane Huang 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

PCI: Fix refcount issue in pci_create_root_bus() error recovery path

2013-07-22T01:21:30+00:00

commit 343df771e671d821478dd3ef525a0610b808dbf8 upstream.

After calling device_register(&bridge->dev), the bridge is reference-
counted, and it is illegal to call kfree() on it except in the release
function.

[bhelgaas: changelog, use put_device() after device_register() failure]
Signed-off-by: Jiang Liu 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

PCI: Finish SR-IOV VF setup before adding the device

2013-07-22T01:21:30+00:00

commit fbf33f516bdbcc2ab1ba1e54dfb720b0cfaa6874 upstream.

Commit 4f535093cf "PCI: Put pci_dev in device tree as early as possible"
moves device registering from pci_bus_add_devices() to pci_device_add().
That causes problems for virtual functions because device_add(&virtfn->dev)
is called before setting the virtfn->is_virtfn flag, which then causes Xen
to report PCI virtual functions as PCI physical functions.

Fix it by setting virtfn->is_virtfn before calling pci_device_add().

[Jiang Liu]: Move the setting of virtfn->is_virtfn ahead further for better
readability and modify changelog.

Signed-off-by: Xudong Hao 
Signed-off-by: Jiang Liu 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

xen/pcifront: Deal with toolstack missing 'XenbusStateClosing' state.

2013-07-22T01:21:27+00:00

commit 098b1aeaf4d6149953b8f1f8d55c21d85536fbff upstream.

There are two tool-stack that can instruct the Xen PCI frontend
and backend to change states: 'xm' (Python code with a daemon),
and 'xl' (C library - does not keep state changes).

With the 'xm', the path to disconnect a single PCI device (xm pci-detach
 ) is:

4(Connected)->7(Reconfiguring*)-> 8(Reconfigured)-> 4(Connected)->5(Closing*).

The * is for states that the tool-stack sets. For 'xl', it is similar:

4(Connected)->7(Reconfiguring*)-> 8(Reconfigured)-> 4(Connected)

Both of them also tear down the XenBus structure, so the backend
state ends up going in the 3(Initialised) and calls pcifront_xenbus_remove.

When a PCI device is plugged back in (xm pci-attach  )
both of them follow the same pattern:

2(InitWait*), 3(Initialized*), 4(Connected*)->4(Connected).

[xen-pcifront ignores the 2,3 state changes and only acts when
4 (Connected) has been reached]

Note that this is for a _single_ PCI device. If there were two
PCI devices and only one was disconnected 'xm' would show the same
state changes.

The problem is that git commit 3d925320e9e2de162bd138bf97816bda8c3f71be
("xen/pcifront: Use Xen-SWIOTLB when initting if required") introduced
a mechanism to initialize the SWIOTLB when the Xen PCI front moves to
Connected state. It also had some aggressive seatbelt code check that
would warn the user if one tried to change to Connected state without
hitting first the Closing state:

 pcifront pci-0: PCI frontend already installed!

However, that code can be relaxed and we can continue on working
even if the frontend is instructed to be the 'Connected' state with
no devices and then gets tickled to be in 'Connected' state again.

In other words, this 4(Connected)->5(Closing)->4(Connected) state
was expected, while 4(Connected)->.... anything but 5(Closing)->4(Connected)
was not. This patch removes that aggressive check and allows
Xen pcifront to work with the 'xl' toolstack (for one or more
PCI devices) and with 'xm' toolstack (for more than two PCI
devices).

Acked-by: Bjorn Helgaas 
Cc: linux-pci@vger.kernel.org
[v2: Added in the description about two PCI devices]
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

ACPI / dock / PCI: Synchronous handling of dock events for PCI devices

2013-06-24T09:22:53+00:00

The interactions between the ACPI dock driver and the ACPI-based PCI
hotplug (acpiphp) are currently problematic because of ordering
issues during hot-remove operations.

First of all, the current ACPI glue code expects that physical
devices will always be deleted before deleting the companion ACPI
device objects.  Otherwise, acpi_unbind_one() will fail with a
warning message printed to the kernel log, for example:

[  185.026073] usb usb5: Oops, 'acpi_handle' corrupt
[  185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
[  185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
[  180.013656]  port1: Oops, 'acpi_handle' corrupt

This means, in particular, that struct pci_dev objects have to
be deleted before the struct acpi_device objects they are "glued"
with.

Now, the following happens the during the undocking of an ACPI-based
dock station:
 1) hotplug_dock_devices() invokes registered hotplug callbacks to
    destroy physical devices associated with the ACPI device objects
    depending on the dock station.  It calls dd->ops->handler() for
    each of those device objects.
 2) For PCI devices dd->ops->handler() points to
    handle_hotplug_event_func() that queues up a separate work item
    to execute _handle_hotplug_event_func() for the given device and
    returns immediately.  That work item will be executed later.
 3) hotplug_dock_devices() calls dock_remove_acpi_device() for each
    device depending on the dock station.  This runs acpi_bus_trim()
    for each of them, which causes the underlying ACPI device object
    to be destroyed, but the work items queued up by
    handle_hotplug_event_func() haven't been started yet.
 4) _handle_hotplug_event_func() queued up in step 2) are executed
    and cause the above failure to happen, because the PCI devices
    they handle do not have the companion ACPI device objects any
    more (those objects have been deleted in step 3).

The possible breakage doesn't end here, though, because
hotplug_dock_devices() may return before at least some of the
_handle_hotplug_event_func() work items spawned by it have a
chance to complete and then undock() will cause _DCK to be
evaluated and that will cause the devices handled by the
_handle_hotplug_event_func() to go away possibly while they are
being accessed.

This means that dd->ops->handler() for PCI devices should not point
to handle_hotplug_event_func().  Instead, it should point to a
function that will do the work of _handle_hotplug_event_func()
synchronously.  For this reason, introduce such a function,
hotplug_event_func(), and modity acpiphp_dock_ops to point to
it as the handler.

Unfortunately, however, this is not sufficient, because if the dock
code were not changed further, hotplug_event_func() would now
deadlock with hotplug_dock_devices() that called it, since it would
run unregister_hotplug_dock_device() which in turn would attempt to
acquire the dock station's hp_lock mutex already acquired by
hotplug_dock_devices().

To resolve that deadlock use the observation that
unregister_hotplug_dock_device() won't need to acquire hp_lock
if PCI bridges the devices on the dock station depend on are
prevented from being removed prematurely while the first loop in
hotplug_dock_devices() is in progress.

To make that possible, introduce a mechanism by which the callers of
register_hotplug_dock_device() can provide "init" and "release"
routines that will be executed, respectively, during the addition
and removal of the physical device object associated with the
given ACPI device handle.  Make acpiphp use two new functions,
acpiphp_dock_init() and acpiphp_dock_release(), that call
get_bridge() and put_bridge(), respectively, on the acpiphp bridge
holding the given device, for this purpose.

In addition to that, remove the dock station's list of
"hotplug devices" and make the dock code always walk the whole list
of "dependent devices" instead in such a way that the loops in
hotplug_dock_devices() and dock_event() (replacing the loops over
"hotplug devices") will take references to the list entries that
register_hotplug_dock_device() has been called for.  That prevents
the "release" routines associated with those entries from being
called while the given entry is being processed and for PCI
devices this means that their bridges won't be removed (by a
concurrent thread) while hotplug_event_func() handling them is
being executed.

This change is based on two earlier patches from Jiang Liu.

References: https://bugzilla.kernel.org/show_bug.cgi?id=59501
Reported-and-tested-by: Alexander E. Patrakov 
Tracked-down-by: Jiang Liu 
Tested-by: Illya Klymov 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Yinghai Lu 
Cc: 3.9+

PCI / ACPI: Use boot-time resource allocation rules during hotplug

2013-06-22T23:01:35+00:00

On x86 platforms, the kernel respects PCI resource assignments from
the BIOS and only reassigns resources for unassigned BARs at boot
time.  However, with the ACPI-based hotplug (acpiphp), it ignores the
BIOS' PCI resource assignments completely and reassigns all resources
by itself.  This causes differences in PCI resource allocation
between boot time and runtime hotplug to occur, which is generally
undesirable and sometimes actively breaks things.

Namely, if there are enough resources, reassigning all PCI resources
during runtime hotplug should work, but it may fail if the resources
are constrained.  This may happen, for instance, when some PCI
devices with huge MMIO BARs are involved in the runtime hotplug
operations, because the current PCI MMIO alignment algorithm may
waste huge chunks of MMIO address space in those cases.

On the Alexander's Sony VAIO VPCZ23A4R the BIOS allocates limited
MMIO resources for the dock station which contains a device
(graphics adapter) with a 256MB MMIO BAR.  An attempt to reassign
that during runtime hotplug causes the dock station MMIO window to be
exhausted and acpiphp fails to allocate resources for the majority
of devices on the dock station as a result.

To prevent that from happening, modify acpiphp to follow the boot
time resources allocation behavior so that the BIOS' resource
assignments are respected during runtime hotplug too.

[rjw: Changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=56531
Reported-and-tested-by: Alexander E. Patrakov 
Tested-by: Illya Klymov 
Signed-off-by: Jiang Liu 
Acked-by: Yinghai Lu 
Cc: 3.9+ 
Signed-off-by: Rafael J. Wysocki