linux-toradex.git/drivers/pci, branch v3.10.9

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

aerdrv: Move cper_print_aer() call out of interrupt context

2013-05-30T17:51:20+00:00

The following warning was seen on 3.9 when a corrected PCIe error was being
handled by the AER subsystem.

WARNING: at .../drivers/pci/search.c:214 pci_get_dev_by_id+0x8a/0x90()

This occurred because a call to pci_get_domain_bus_and_slot() was added to
cper_print_pcie() to setup for the call to cper_print_aer().  The warning
showed up because cper_print_pcie() is called in an interrupt context and
pci_get* functions are not supposed to be called in that context.

The solution is to move the cper_print_aer() call out of the interrupt
context and into aer_recover_work_func() to avoid any warnings when calling
pci_get* functions.

Signed-off-by: Lance Ortiz 
Acked-by: Borislav Petkov 
Acked-by: Rafael J. Wysocki 
Signed-off-by: Tony Luck

PCI: acpiphp: Re-enumerate devices when host bridge receives Bus Check

2013-05-17T20:12:06+00:00

When a PCI host bridge device receives a Bus Check notification, we
must re-enumerate starting with the bridge to discover changes (devices
that have been added or removed).

Prior to 668192b678 ("PCI: acpiphp: Move host bridge hotplug to
pci_root.c"), this happened in _handle_hotplug_event_bridge().  After that
commit, _handle_hotplug_event_bridge() is not installed for host bridges,
and the host bridge notify handler, _handle_hotplug_event_root() did not
re-enumerate.

This patch adds re-enumeration to _handle_hotplug_event_root().

This fixes cases where we don't notice the addition or removal of
PCI devices, e.g., the PCI-to-USB ExpressCard in the bugzilla below.

[bhelgaas: changelog, references]
Reference: https://lkml.kernel.org/r/CAAh6nkmbKR3HTqm5ommevsBwhL_u0N8Rk7Wsms_LfP=nBgKNew@mail.gmail.com
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=57961
Reported-by: Gavin Guo 
Tested-by: Gavin Guo 
Signed-off-by: Yinghai Lu 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Jiang Liu 
Acked-by: Rafael J. Wysocki 
CC: stable@vger.kernel.org	# v3.9+