We can't do ASPM configuration at enumeration-time because enabling it
makes some defective hardware unresponsive, even if ASPM is disabled later
(see 41cd766b ("PCI: Don't enable aspm before drivers have had a chance
to veto it").  Therefore, we have to do it after a driver claims the
device.

We previously configured ASPM in pci_set_power_state(), but that's not a
very good place because it's not really related to setting the PCI device
power state, and doing it there means:

  - We incorrectly skipped ASPM config when setting a device that's
    already in D0 to D0.

  - We unnecessarily configured ASPM when setting a device to a low-power
    state (the ASPM feature only applies when the device is in D0).

  - We unnecessarily configured ASPM when called from a .resume() method
    (ASPM configuration needs to be restored during resume, but
    pci_restore_pcie_state() should already do this).

Move ASPM configuration from pci_set_power_state() to
do_pci_enable_device() so we do it when a driver enables a device.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=79621
Fixes: db288c9c ("PCI / PM: restore the original behavior of pci_set_power_state()")
Suggested-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NVidya Sagar <sagar.tv@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v3.6+

Commit d92a208d ("powerpc/pci: Mask linkDown on resetting PCI bus")
implemented same logic (resetting PCI secondary bus by bridge's config
register PCI_BRIDGE_CTL_BUS_RESET) in PCI core and arch-dependent code.  To
avoid the duplication, move the logic to pci_reset_secondary_bus().

That commit did not declare the pcibios_reset_secondary_bus() interface in
linux/include/pci.h.  Add the declaration.

No functional change.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

pci_wait_for_pending() uses word access, so we shouldn't be passing
an offset that is only byte aligned.  Use the control register offset
instead, shifting the mask to match.

Fixes: d0b4cc4e ("PCI: Wrong register used to check pending traffic")
Fixes: 157e876f ("PCI: Add pci_wait_for_pending() (refactor pci_wait_for_pending_transaction())
Reported-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
CC: stable@vger.kernel.org	# v3.14+

Merge quoted strings that are broken across lines into a single entity.
The compiler merges them anyway, but checkpatch complains about it, and
merging them makes it easier to grep for strings.

No functional change.

[bhelgaas: changelog, do the same for everything under drivers/pci]
Signed-off-by: NRyan Desfosses <ryan@desfo.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Fix various whitespace errors.

No functional change.

[bhelgaas: fix other similar problems]
Signed-off-by: NRyan Desfosses <ryan@desfo.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Move EXPORT_SYMBOL so it immediately follows the function or variable.

No functional change.

[bhelgaas: squash similar changes, fix hotplug, probe, rom, search, too]
Signed-off-by: NRyan Desfosses <ryan@desfo.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

pcibios_penalize_isa_irq() is only implemented by x86 now, and legacy ISA
is not used by some architectures.  Make pcibios_penalize_isa_irq() a
__weak function to simplify the code.  This removes the need for new
platforms to add stub implementations of pcibios_penalize_isa_irq().

[bhelgaas: changelog, comments]
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Notify a PCI device driver when its device's access is about to be disabled
for an impending reset attempt, then after the attempt completes and device
access is restored.  The notification is via the pci_error_handlers
interface.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The incorrect register offset is passed to pci_wait_for_pending(), which is
caused by commit 157e876f ("PCI: Add pci_wait_for_pending() (refactor
pci_wait_for_pending_transaction())").

Fixes: 157e876f ("PCI: Add pci_wait_for_pending() (refactor pci_wait_for_pending_transaction())
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NAlex Williamson <alex.williamson@gmail.com>
CC: stable@vger.kernel.org	# v3.14+

change made to resolve following checkpatch message:
    drivers/pci/pci.c:109: ERROR: "foo* bar" should be "foo *bar"
branch: Linux 3.14-rc8
Signed-off-by: NRyan Desfosses <ryan@desfo.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The problem was initially reported by Wendy who tried pass through
IPR adapter, which was connected to PHB root port directly, to KVM
based guest. When doing that, pci_reset_bridge_secondary_bus() was
called by VFIO driver and linkDown was detected by the root port.
That caused all PEs to be frozen.

The patch fixes the issue by routing the reset for the secondary bus
of root port to underly firmware. For that, one more weak function
pci_reset_secondary_bus() is introduced so that the individual platforms
can override that and do specific reset for bridge's secondary bus.
Reported-by: NWendy Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

3448a19d "vgaarb: use bridges to control VGA routing where possible"
added the "flags & PCI_VGA_STATE_CHANGE_DECODES" condition to an existing
WARN_ON(), but used bitwise AND (&) instead of logical AND (&&), so the
condition is never true.  Replace with logical AND.

Found by Coverity (CID 142811).

Fixes: 3448a19d "vgaarb: use bridges to control VGA routing where possible"
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NDavid Airlie <airlied@redhat.com>

Many architectures implement pcibios_enable_device() the same way, so
provide a default implementation in the core.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Andreas reported that after 1f42db78 ("PCI: Enable INTx if BIOS left
them disabled"), pciehp surprise removal stopped working.

This happens because pci_reenable_device() on the hotplug bridge (used in
the pciehp_configure_device() path) clears the Interrupt Disable bit, which
apparently breaks the bridge's MSI hotplug event reporting.

Previously we cleared the Interrupt Disable bit in do_pci_enable_device(),
which is used by both pci_enable_device() and pci_reenable_device().  But
we use pci_reenable_device() after the driver may have enabled MSI or
MSI-X, and we *set* Interrupt Disable as part of enabling MSI/MSI-X.

This patch clears Interrupt Disable only when MSI/MSI-X has not been
enabled.

Fixes: 1f42db78 PCI: Enable INTx if BIOS left them disabled
Link: https://bugzilla.kernel.org/show_bug.cgi?id=71691Reported-and-tested-by: NAndreas Noever <andreas.noever@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>

Andreas reported that after 1f42db78 ("PCI: Enable INTx if BIOS left
them disabled"), pciehp surprise removal stopped working.

This happens because pci_reenable_device() on the hotplug bridge (used in
the pciehp_configure_device() path) clears the Interrupt Disable bit, which
apparently breaks the bridge's MSI hotplug event reporting.

Previously we cleared the Interrupt Disable bit in do_pci_enable_device(),
which is used by both pci_enable_device() and pci_reenable_device().  But
we use pci_reenable_device() after the driver may have enabled MSI or
MSI-X, and we *set* Interrupt Disable as part of enabling MSI/MSI-X.

This patch clears Interrupt Disable only when MSI/MSI-X has not been
enabled.

Fixes: 1f42db78 PCI: Enable INTx if BIOS left them disabled
Link: https://bugzilla.kernel.org/show_bug.cgi?id=71691Reported-and-tested-by: NAndreas Noever <andreas.noever@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>

When assigning addresses to resources, mark them with IORESOURCE_UNSET
before we start and clear IORESOURCE_UNSET if assignment is successful.
That means that if we print the resource during assignment, we will show
the size, not a meaningless address.

Also, clear IORESOURCE_UNSET if we do assign an address, so we print the
address when it is valid.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

If the resource hasn't been allocated yet, pci_find_parent_resource() is
documented as returning the region "where it should be allocated from."
This is impossible in general because there may be several candidates: a
prefetchable BAR can be put in either a prefetchable or non-prefetchable
window, a transparent bridge may have overlapping positively- and
subtractively-decoded windows, and a root bus may have several windows of
the same type.

Allocation should be done by pci_bus_alloc_resource(), which iterates
through all bus resources and looks for the best match, e.g., one with the
desired prefetchability attributes, and falls back to less-desired
possibilities.

The only valid use of pci_find_parent_resource() is to find the parent of
an already-allocated resource so we can claim it via request_resource(),
and all we need for that is a bus region of the correct type that contains
the resource.

Note that like 8c8def26 ("PCI: allow matching of prefetchable resources
to non-prefetchable windows"), this depends on pci_bus_for_each_resource()
iterating through positively-decoded regions before subtractively-decoded
ones.  We prefer not to return a subtractively-decoded region because
requesting from it will likely conflict with the overlapping positively-
decoded window (see Launchpad report below).

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/424142Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>

Some firmware leaves the Interrupt Disable bit set even if the device uses
INTx interrupts.  Clear Interrupt Disable so we get those interrupts.

Based on the report mentioned below, if the user selects the "EHCI only"
option in the Intel Baytrail BIOS, the EHCI device is handed off to the OS
with the PCI_COMMAND_INTX_DISABLE bit set.

Link: http://lkml.kernel.org/r/20140114181721.GC12126@xanatos
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70601Reported-by: NChris Cheng <chris.cheng@atrustcorp.com>
Reported-and-tested-by: NJamie Chen <jamie.chen@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>

Some firmware leaves the Interrupt Disable bit set even if the device uses
INTx interrupts.  Clear Interrupt Disable so we get those interrupts.

Based on the report mentioned below, if the user selects the "EHCI only"
option in the Intel Baytrail BIOS, the EHCI device is handed off to the OS
with the PCI_COMMAND_INTX_DISABLE bit set.

Link: http://lkml.kernel.org/r/20140114181721.GC12126@xanatos
Link: https://bugzilla.kernel.org/show_bug.cgi?id=70601Reported-by: NChris Cheng <chris.cheng@atrustcorp.com>
Reported-and-tested-by: NJamie Chen <jamie.chen@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>

Replace list_for_each() with list_for_each_entry(), which means we no
longer need pci_bus_b() and can remove it.
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Some devices support PCI ACS-like features, but don't report it using the
standard PCIe capabilities.  We already provide hooks for device-specific
testing of ACS, but not for device-specific enabling of ACS.  This provides
that setup hook.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

list_for_each_entry() handles empty lists just fine, so there's no need to
check whether the list is empty first.

No functional change.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>

Fix typos in pci_check_and_unmask_intx() function comment.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

When doing a function/slot/bus reset PCI grabs the device_lock for each
device to block things like suspend and driver probes, but call paths exist
where this lock may already be held.  This creates an opportunity for
deadlock.  For instance, vfio allows userspace to issue resets so long as
it owns the device(s).  If a driver unbind .remove callback races with
userspace issuing a reset, we have a deadlock as userspace gets stuck
waiting on device_lock while another thread has device_lock and waits for
.remove to complete.  To resolve this, we can make a version of the reset
interfaces which use trylock.  With this, we can safely attempt a reset and
return error to userspace if there is contention.

[bhelgaas: the deadlock happens when A (userspace) has a file descriptor for
the device, and B waits in this path:

  driver_detach
    device_lock                     # take device_lock
    __device_release_driver
      pci_device_remove             # pci_bus_type.remove
        vfio_pci_remove             # pci_driver .remove
          vfio_del_group_dev
            wait_event(vfio.release_q, !vfio_dev_present)   # wait (holding device_lock)

Now B is stuck until A gives up the file descriptor.  If A tries to acquire
device_lock for any reason, we deadlock because A is waiting for B to release
the lock, and B is waiting for A to release the file descriptor.]
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Using 'make namespacecheck' identify code which should be declared static.
Checked for users in other driver/archs as well.  Compile tested only.

This stops exporting the following interfaces to modules:

    pci_target_state()
    pci_load_saved_state()

[bhelgaas: retained pci_find_next_ext_capability() and pci_cfg_space_size()]
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This reverts b48d4425 ("PCI: add ID-based ordering enable/disable
support"), removing these interfaces:

    pci_enable_ido()
    pci_disable_ido()

[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>

My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This reverts 48a92a81 ("PCI: add OBFF enable/disable support"),
removing these interfaces:

    pci_enable_obff()
    pci_disable_obff()

[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>

My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This reverts 51c2e0a7 ("PCI: add latency tolerance reporting
enable/disable support"), removing these interfaces:

    pci_enable_ltr()
    pci_disable_ltr()
    pci_set_ltr()

[bhelgaas: split to separate patch, also remove prototypes from pci.h]
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>

While we don't really have any infrastructure for making use of VC
support, the system BIOS can configure the topology to non-default
VC values prior to boot.  This may be due to silicon bugs, desire to
reserve traffic classes, or perhaps just BIOS bugs.  When we reset
devices, the VC configuration may return to default values, which can
be incompatible with devices upstream.  For instance, Nvidia GRID
cards provide a PCIe switch and some number of GPUs, all supporting
VC.  The power-on default for VC is to support TC0-7 across VC0,
however some platforms will only enable TC0/VC0 mapping across the
topology.  When we do a secondary bus reset on the downstream switch
port, the GPU is reset to a TC0-7/VC0 mapping while the opposite end
of the link only enables TC0/VC0.  If the GPU attempts to use TC1-7,
it fails.

This patch attempts to provide complete support for VC save/restore,
even beyond the minimally required use case above.  This includes
save/restore and reload of the arbitration table, save/restore and
reload of the port arbitration tables, and re-enabling of the
channels for VC, VC9, and MFVC capabilities.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Current save/restore is specific to standard capabilities.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

We currently have two instance of this loop which waits for a pending bit
to clear in a status dword.  Generalize the function for future users.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Modify tg3_chip_reset() and tg3_close() to check if the PCI network
adapter device is accessible at all in order to skip poking it or
trying to handle a carrier loss in vain when that's not the case.
Introduce a special PCI helper function pci_device_is_present()
for this purpose.

Of course, this uncovers the lack of the appropriate RTNL locking
in tg3_suspend() and tg3_resume(), so add that locking in there
too.

These changes prevent tg3 from burning a CPU at 100% load level for
solid several seconds after the Thunderbolt link is disconnected from
a Matrox DS1 docking station.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix whitespace, capitalization, and spelling errors.  No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Previously we enabled the upstream PCI-to-PCI bridge only when
"dev->bus->self != NULL".  In the case of a VF on a virtual bus, where
"bus->self == NULL", we didn't enable the upstream bridge.

This fixes that by enabling the upstream bridge of the PF corresponding to
the VF.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

f41f064c ("PCI: Workaround missing pci_set_master in pci drivers") made
pci_enable_bridge() turn on bus mastering if the driver hadn't done so
already.  It also added a warning in this case.  But there's no reason to
warn about it unless it's actually a problem to enable bus mastering here.

This patch drops the warning because I'm not aware of any such problem.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Paul Bolle <pebolle@tiscali.nl>

Ben Herrenschmidt found that commit 928bea96 ("PCI: Delay enabling
bridges until they're needed") breaks PCI in some powerpc environments.

The reason is that the PCIe port driver will call pci_enable_device() on
the bridge, so the device is enabled, but skips pci_set_master because
pcie_port_auto and no acpi on powerpc.

Because of that, pci_enable_bridge() later on (called as a result of the
child device driver doing pci_enable_device) will see the bridge as
already enabled and will not call pci_set_master() on it.

Fixed by add checking in pci_enable_bridge, and call pci_set_master
if driver skip that.

That will make the code more robot and wade off problem for missing
pci_set_master in drivers.
Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Previously, if kmalloc() failed, we claimed "PME# enabled" in dmesg,
even though we didn't add the device to the pci_pme_list.  This prints
a more correct warning.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Ben Herrenschmidt found that commit 928bea96 ("PCI: Delay enabling
bridges until they're needed") breaks PCI in some powerpc environments.

The reason is that the PCIe port driver will call pci_enable_device() on
the bridge, so the device is enabled, but skips pci_set_master because
pcie_port_auto and no acpi on powerpc.

Because of that, pci_enable_bridge() later on (called as a result of the
child device driver doing pci_enable_device) will see the bridge as
already enabled and will not call pci_set_master() on it.

Fixed by add checking in pci_enable_bridge, and call pci_set_master
if driver skip that.

That will make the code more robot and wade off problem for missing
pci_set_master in drivers.
Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This message isn't useful any more, so drop it.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60636Reported-by: NOleksil Shevchuk <alxchk@gmail.com>
Reference: http://lkml.kernel.org/r/CALCETrWkr53ZjqdN3t7rTTfr=+ZKZXJoYsuBcwPf0kN_33GfAw@mail.gmail.comReported-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Export pcie_get_mps() and pcie_set_mps() functions so drivers can use
them to simplify code.
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>