Merge branches 'pci/host-aardvark', 'pci/host-altera', 'pci/host-artpec', 'pci/host-designware', 'pci/host-hv', 'pci/host-keystone', 'pci/host-rcar', 'pci/host-rockchip', 'pci/host-tegra' and 'pci/host-xilinx' into next

* pci/host-aardvark:
  PCI: aardvark: Remove redundant dev_err call in advk_pcie_probe()

* pci/host-altera:
  PCI: altera: Remove redundant platform_get_resource() return value check
  PCI: altera: Move retrain from fixup to altera_pcie_host_init()
  PCI: altera: Rework config accessors for use without a struct pci_bus
  PCI: altera: Poll for link training status after retraining the link

* pci/host-artpec:
  PCI: artpec6: Drop __init from artpec6_add_pcie_port()

* pci/host-designware:
  PCI: designware: Remove redundant platform_get_resource() return value check
  PCI: designware: Exchange viewport of `MEMORYs' and `CFGs/IOs'
  PCI: designware: Keep viewport fixed for IO transaction if num_viewport > 2
  PCI: designware: Check LTSSM training bit before deciding link is up
  PCI: designware: Add iATU Unroll feature
  PCI: designware: Wait for iATU enable
  PCI: designware: Move link wait definitions to .c file
  PCI: designware: Return data directly from dw_pcie_readl_rc()

* pci/host-hv:
  PCI: hv: Handle hv_pci_generic_compl() error case
  PCI: hv: Handle vmbus_sendpacket() failure in hv_compose_msi_msg()
  PCI: hv: Remove the unused 'wrk' in struct hv_pcibus_device
  PCI: hv: Use pci_function_description[0] in struct definitions
  PCI: hv: Use zero-length array in struct pci_packet
  PCI: hv: Use list_move_tail() instead of list_del() + list_add_tail()

* pci/host-keystone:
  PCI: keystone: Propagate request_irq() failure

* pci/host-rcar:
  PCI: rcar: Try increasing PCIe link speed to 5 GT/s at boot
  PCI: rcar: Fix some checkpatch warnings
  PCI: rcar: Add multi-MSI support
  PCI: rcar: Don't disable/unprepare clocks on prepare/enable failure
  PCI: rcar: Consolidate register space lookup and ioremap

* pci/host-rockchip:
  PCI: rockchip: Fix wrong transmitted FTS count
  PCI: rockchip: Improve the deassert sequence of four reset pins
  PCI: rockchip: Increase the Max Credit update interval
  PCI: rockchip: Add Rockchip PCIe controller support
  dt-bindings: PCI: rockchip: Add DT bindings for Rockchip PCIe controller

* pci/host-tegra:
  PCI: tegra: Use of_device_get_match_data()
  PCI: tegra: Remove redundant _data suffix

* pci/host-xilinx:
  microblaze/PCI: Add multidomain support for procfs
  PCI: xilinx: Dispose of MSI virtual IRQ
  PCI: xilinx: Clear correct MSI set bit
  PCI: xilinx: Clear interrupt register for invalid interrupt
  PCI: xilinx: Keep both legacy and MSI interrupt domain references
  PCI: xilinx-nwl: Enable all MSI interrupts using MSI mask
  PCI: xilinx-nwl: Expand error logging

Conflicts:
	drivers/pci/host/pcie-xilinx.c

If the expected number of FTS aren't received by RC when exiting from L0s,
the LTSSM will fall into recover state, which means it will need to send TS
for retraining which makes the latency of exiting from L0s a little longer
than expected.  This issue is caused by an incorrect reset value of FTS
count on PLC1 register (offset 0x4).  The expected value for Gen1/2 should
be more than 240 and we may leave a little margin here.  Fix this before
starting Gen1 training which will make TS1 contain the correct FTS count.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Per TRM, we need to deassert the four reset pins simultaneously.  Currently
the reset framework doesn't support that so we did it one by one.  It seems
no side effect found but it does impact the state machine of controller, so
sometimes the change speed bit is not set when sending training sequence
from recover state.  After the silicon RTL review from SoC guys, we don't
need to do the sequence recommended by TRM, and could just move the
deassert of mgmt_sticky_rst to the first place.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Increase the likelihood of link state to automatically go to L1 and save
some power.

The default credit update interval of 7.5 us results in the rootport
sending UpdateFC-P and UpdateFC-NP packets too often, thus resulting in the
link never going to L1, and always staying in L0/L0s.  The value 24 us was
chosen after some experiments and peeking over the PCIe bus to see that we
do enter L1 substate when there is not enough traffic on the PCIe bus.
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Shawn Lin <shawn.lin@rock-chips.com>

The PCIe link speed is initially set to 2.5 GT/s.  Try to increase the link
speed to 5 GT/s.

Based on original patch by Grigory Kletsko
<grigory.kletsko@cogentembedded.com>.

[bhelgaas: remove "Trying speed up" message, remove unused SPCHG]
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>

* pci/virtualization:
  PCI: xilinx: Relax device number checking to allow SR-IOV
  PCI: designware: Relax device number checking to allow SR-IOV
  PCI: altera: Relax device number checking to allow SR-IOV
  PCI: Check for pci_setup_device() failure in pci_iov_add_virtfn()
  PCI: Mark Atheros AR9580 to avoid bus reset

* pci/resource:
  PCI: Ignore requested alignment for VF BARs
  PCI: Ignore requested alignment for PROBE_ONLY and fixed resources

* pci/pm:
  PCI: Avoid unnecessary resume after direct-complete
  PCI: Recognize D3cold in pci_update_current_state()
  PCI: Query platform firmware for device power state
  PCI: Afford direct-complete to devices with non-standard PM

* pci/msi:
  PCI/MSI: Enable PCI_MSI_IRQ_DOMAIN support for ARC

* pci/misc:
  PCI: Drop CONFIG_KEXEC_CORE ifdeffery

* pci/hotplug:
  x86/PCI: VMD: Request userspace control of PCIe hotplug indicators
  PCI: pciehp: Allow exclusive userspace control of indicators
  PCI: pciehp: Remove useless pciehp_get_latch_status() calls
  PCI: pciehp: Clean up dmesg "Slot(%s)" messages
  PCI: pciehp: Remove unnecessary guard
  PCI: pciehp: Don't re-read Slot Status when handling surprise event
  PCI: pciehp: Don't re-read Slot Status when queuing hotplug event
  PCI: pciehp: Process all hotplug events before looking for new ones
  PCI: pciehp: Return IRQ_NONE when we can't read interrupt status
  PCI: pciehp: Rename pcie_isr() locals for clarity
  PCI: pciehp: Clear attention LED on device add

* pci/enumeration:
  PCI: tegra: Fix pci_remap_iospace() failure path
  PCI: generic: Fix pci_remap_iospace() failure path
  PCI: rcar: Fix pci_remap_iospace() failure path
  PCI: versatile: Fix pci_remap_iospace() failure path
  PCI: designware: Fix pci_remap_iospace() failure path
  PCI: aardvark: Fix pci_remap_iospace() failure path

* pci/aer:
  PCI/AER: Fix aer_probe() kernel-doc comment
  PCI/AER: Cache capability position
  PCI/AER: Avoid memory allocation in interrupt handling path
  ACPI / APEI: Send correct severity to calculate AER severity
  PCI/AER: Remove duplicate AER severity translation
  PCI/AER: Remove aerdriver.forceload kernel parameter
  PCI/AER: Remove aerdriver.nosourceid kernel parameter
  x86/PCI: VMD: Add quirk for AER to ignore source ID
  PCI/AER: Add bus flag to skip source ID matching

Conflicts:
	drivers/pci/probe.c

0516c8bc ("PCI: PCIe portdrv: Simplily probe callback of service
drivers") removed the "id" argument of aer_probe() but neglected to remove
the kernel-doc comment.  Update the comment.

[bhelgaas: changelog]
Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Resource allocation for VFs is done via the VF BARx registers in the PF's
SR-IOV Capability, and the BARs in the VFs themselves are read-only zeros
(see SR-IOV spec r1.1, secs 3.3.14 and 3.4.1.11).

Even though the actual VF BARs are read-only zeros, the VF dev->resource[]
structs describe the space allocated for the VF (this is a piece of the
space described by the VF BARx register in the PF's SR-IOV capability).

It's meaningless to request additional alignment for a VF: the VF BAR
alignment is completely determined by the alignment of the VF BARx in the
PF and the size of the VF BAR.

Ignore the user's alignment requests for VF devices.
Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Users may request additional alignment of PCI resources, e.g., to align
BARs on page boundaries so they can be shared with guests via VFIO.  This
of course may require reallocation if firmware has already assigned the
BARs with smaller alignments.

If the platform has requested PCI_PROBE_ONLY, we should never change any
PCI BARs, so we can't provide any additional alignment.  Also, if a BAR is
marked as IORESOURCE_PCI_FIXED, e.g., for PCI Enhanced Allocation or if the
firmware depends on the current BAR value, we can't change the alignment.

In these cases, log a message and ignore the user's alignment requests.

[bhelgaas: changelog, use goto to simplify PCI_PROBE_ONLY check]
Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Commit 58a1fbbb ("PM / PCI / ACPI: Kick devices that might have been
reset by firmware") added a runtime resume for devices that were runtime
suspended when the system entered sleep.

The motivation was that devices might be in a reset-power-on state after
waking from system sleep, so their power state as perceived by Linux
(stored in pci_dev->current_state) would no longer reflect reality.  By
resuming such devices, we allow them to return to a low-power state via
autosuspend and also bring their current_state in sync with reality.

However for devices that are *not* in a reset-power-on state, doing an
unconditional resume wastes energy.  A more refined approach is called for
which issues a runtime resume only if the power state after direct-complete
is shallower than it was before. To achieve this, update the device's
current_state and compare it to its pre-sleep value.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Whenever a device is resumed or its power state is changed using the
platform, its new power state is read from the PM Control & Status Register
and cached in pci_dev->current_state by calling pci_update_current_state().

If the device is in D3cold, reading from config space typically results in
a fabricated "all ones" response.  But if it's in D3hot, the two bits
representing the power state in the PMCSR are *also* set to 1.  Thus D3hot
and D3cold are not discernible by just reading the PMCSR.

To account for this, pci_update_current_state() uses two workarounds:

- When transitioning to D3cold using pci_platform_power_transition(), the
  new power state is set blindly by pci_update_current_state(), i.e.
  without verifying that the device actually *is* in D3cold.  This is
  achieved by setting the "state" argument to PCI_D3cold.  The "state"
  argument was originally intended to convey the new state in case the
  device doesn't have the PM capability.  It is *also* used to convey the
  device state if the PM capability is present and the new state is D3cold,
  but this was never explained in the kerneldoc.

- Once the current_state is set to D3cold, further invocations of
  pci_update_current_state() will blindly assume that the device is still
  in D3cold and leave the current_state unmodified.  To get out of this
  impasse, the current_state has to be set directly, typically by calling
  pci_raw_set_power_state() or pci_enable_device().

It would be desirable if pci_update_current_state() could reliably detect
D3cold by itself.  That would allow us to do away with these workarounds,
and it would allow for a smarter, more energy conserving runtime resume
strategy after system sleep:  Currently devices which utilize
direct_complete are mandatorily runtime resumed in their ->complete stage.
This can be avoided if their power state after system sleep is the same as
before, but it requires a mechanism to detect the power state reliably.

We've just gained the ability to query the platform firmware for its
opinion on the device's power state.  On platforms conforming to ACPI 4.0
or newer, this allows recognition of D3cold.  Pre-4.0 platforms lack _PR3
and therefore the deepest power state that will ever be reported is D3hot,
even though the device may actually be in D3cold.  To detect D3cold in
those cases, accessibility of the vendor ID in config space is probed using
pci_device_is_present().  This also works for devices which are not
platform-power-manageable at all, but can be suspended to D3cold using a
nonstandard mechanism (e.g. some hybrid graphics laptops or Thunderbolt on
the Mac).
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Usually the most accurate way to determine a PCI device's power state is to
read its PM Control & Status Register.  There are two cases however when
this is not an option:  If the device doesn't have the PM capability at
all, or if it is in D3cold (in which case its config space is
inaccessible).

In both cases, we can alternatively query the platform firmware for its
opinion on the device's power state.  To facilitate this, augment struct
pci_platform_pm_ops with a ->get_power callback and implement it for
acpi_pci_platform_pm (the only pci_platform_pm_ops existing so far).

It is used by a forthcoming commit to let pci_update_current_state()
recognize D3cold.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There are devices not power-manageable by the platform, but still able to
runtime suspend to D3cold with a non-standard mechanism.  One example is
laptop hybrid graphics where the discrete GPU and its built-in HDA
controller are power-managed either with a _DSM (AMD PowerXpress, Nvidia
Optimus) or a separate gmux controller (MacBook Pro).  Another example is
Thunderbolt on Macs which is power-managed with custom ACPI methods.

When putting the system to sleep, we currently handle such devices
improperly by transitioning them from D3cold to D3hot (the default power
state defined at the top of pci_target_state()).  This wastes energy and
prolongs the suspend sequence (powering up the Thunderbolt controller takes
2 seconds).

Avoid that by assuming that a non-standard PM mechanism is at work if the
device is not platform-power-manageable but currently in D3cold.

If the device is wakeup enabled, we might still have to wake it up from
D3cold if PME cannot be signaled from that power state.

The check for devices without PM capability comes before the check for
D3cold since such devices could in theory also be powered down by
non-standard means and should then be afforded direct-complete as well.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Save the position of the error reporting capability so it doesn't need to
be rediscovered during error handling.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Lukas Wunner <lukas@wunner.de>

When handling AER events, we previously allocated a struct aer_err_info,
processed the error, and freed the struct.  But aer_isr_one_error() is
serialized by rpc_mutex, so we never need more than one copy of the struct,
and the struct is only about 70 bytes, so we're not saving much by
allocating it dynamically.

Embed a struct aer_err_info directly in struct aer_rpc, which is allocated
at probe-time by aer_probe().

[bhelgaas: changelog]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Add set_dev_domain_options() to set PCI domain-specific options as devices
are added.  The first usage is to request exclusive userspace control of
PCIe hotplug indicators in VMD domains.

Devices in a VMD domain use PCIe hotplug Attention and Power Indicators in
a non-standard way; tell pciehp to ignore the indicators so userspace can
control them via the sysfs "attention" file.

To determine whether a bus is within a VMD domain, add a bool to the
pci_sysdata structure that the VMD driver sets during initialization.

[bhelgaas: changelog]
Requested-by: Kapil Karkra <kapil.karkra@intel.com>
Tested-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCIe hotplug supports optional Attention and Power Indicators, which are
used internally by pciehp.  Users can't control the Power Indicator, but
they can control the Attention Indicator by writing to a sysfs "attention"
file.

The Slot Control register has two bits for each indicator, and the PCIe
spec defines the encodings for each as (Reserved/On/Blinking/Off).  For
sysfs "attention" writes, pciehp_set_attention_status() maps into these
encodings, so the only useful write values are 0 (Off), 1 (On), and 2
(Blinking).

However, some platforms use all four bits for platform-specific indicators,
and they need to allow direct user control of them while preventing pciehp
from using them at all.

Add a "hotplug_user_indicators" flag to the pci_dev structure.  When set,
pciehp does not use either the Attention Indicator or the Power Indicator,
and the low four bits (values 0x0 - 0xf) of sysfs "attention" write values
are written directly to the Attention Indicator Control and Power Indicator
Control fields.

[bhelgaas: changelog, rename flag and accessors to s/attention/indicator/]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Currently the AER severity is calculated by calling cper_severity_to_aer(),
but the parameter sent is actually the GHES severity.  This causes the AER
severity to be incorrect.

Fix the parameter to be the CPER severity instead of the GHES severity.
Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Borislav Petkov <bp@suse.de>

Currently the AER severity is being translated twice in the code flow for
PCIe errors.  It is first translated in ghes_do_proc() before calling into
the AER driver.  Then it is translated again when the AER driver calls
cper_print_aer().  This causes the severity that is used in
cper_print_aer() to be incorrect.

Remove the second translation that is in cper_print_aer() since this
function is already receiving the correct AER severity.
Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Borislav Petkov <bp@suse.de>

artpec6_add_pcie_port() is called from artpec6_pcie_probe(), which is not
marked __init.  It is wrong to call an __init function from a non-__init
one, so remove __init from artpec6_add_pcie_port().

[bhelgaas: changelog]
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The R-Car PCIe driver causes 13 warnings from scripts/checkpatch.pl --
let's fix at least 10 easier ones:

  - line over 80 characters;
  - blank line missing after declarations;
  - statements not starting on a tabstop.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>

Implement the MSI .setup_irqs() method which enables allocation of several
MSIs at once.

[Sergei Shtylyov: removed unrelated/unneeded changes, fixed too long lines,
reordered the variable declarations, reworded the summary/description.]
Signed-off-by: Grigory Kletsko <grigory.kletsko@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>

Per the PCI Firmware spec, r3.0, sec 4.5.1, on ACPI systems, the OS must
not use AER unless _OSC is present and _OSC grants AER control to the OS.
The aerdriver.forceload kernel parameter was a way to enable Linux AER
support on ACPI systems that lack _OSC or fail to grant control the the OS.

Enabling Linux AER support when the firmware doesn't want us to is a recipe
for problems, e.g., the firmware might be handling AER itself.

Remove the aerdriver.forceload kernel parameter and related supporting
code.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The aerdriver.nosourceid kernel parameter was intended for working around
broken chipsets don't supply the source ID for AER events.  We recently
added PCI_BUS_FLAGS_NO_AERSID, which can be set by quirks for the same
purpose.

Remove the aerdriver.nosourceid kernel parameter.  For anything other than
debugging, asking users to find and use kernel parameters is a poor user
experience.  Instead, we should add PCI_BUS_FLAGS_NO_AERSID quirks for any
hardware that needs it.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Long ago, we updated a "switch_save" field based on the latch status.  But
switch_save was unused, and ed6cbcf2 ("[PATCH] pciehp: miscellaneous
cleanups") removed it.

We no longer use the latch status, so remove calls to
pciehp_get_latch_status().  No functional change intended.
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Print slot name consistently as "Slot(%s)".  I don't know whether that's
ideal, but we can at least do it the same way all the time.  No functional
change intended.
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

In pcie_isr(), we return early if no status bits other than
PCI_EXP_SLTSTA_CC are set.  This was introduced by dbd79aed ("pciehp:
fix NULL dereference in interrupt handler"), but it is no longer necessary
because all the subsequent pcie_isr() code is already predicated on a
status bit being set.

Remove the unnecessary test for ~PCI_EXP_SLTSTA_CC.  No functional change
intended.
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Previously we read Slot Status when handling a surprise event.  But Slot
Status might have changed since we identified the event, and the event_type
already tells us whether to enable or disable the slot, so there's no need
to read it again.

Remove handle_surprise_event() and queue the power work directly.

[bhelgaas: changelog]
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mayurkumar Patel <mayurkumar.patel@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rajat Jain <rajatxjain@gmail.com>

Previously we read Slot Status to learn about hotplug events, then cleared
the events, then re-read Slot Status to find out what happened.  But Slot
Status might have changed before the second read.

Capture the Slot Status once before clearing the events.  Also capture the
Link Status if we had a link status change.

[bhelgaas: changelog, split to separate patch]
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mayurkumar Patel <mayurkumar.patel@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Previously we accumulated hotplug events, then processed them, essentially
like this:

  events = 0
  do {
    status = read(Slot Status)
    status &= EVENT_MASK              # only look at events
    events |= status                  # accumulate events
    write(Slot Status, events)        # clear events
  } while (status)
  process events

The problem is that as soon as we clear events in Slot Status, the hardware
may send notifications for new events, and we lose information about the
first events.  For example, we might see two Presence Detect Changed
events, but lose the fact that the slot was temporarily empty:

  read  PCI_EXP_SLTSTA_PDC set, PCI_EXP_SLTSTA_PDS clear  # slot empty
  write PCI_EXP_SLTSTA_PDC                                # clear PDC event
  read  PCI_EXP_SLTSTA_PDC set, PCI_EXP_SLTSTA_PDS set    # slot occupied

The current code does not process a removal; it only processes the
insertion, which fails because we didn't remove the original device.

To avoid this problem, read Slot Status once and process all the events
before reading it again, like this:

  do {
    read events
    clear events
    process events
  } while (events)

[bhelgaas: changelog, add external loop around pciehp_isr()]
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mayurkumar Patel <mayurkumar.patel@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

After 1469d17d ("PCI: pciehp: Handle invalid data when reading from
non-existent devices"), we returned IRQ_HANDLED when we failed to read
interrupt status from the bridge.  I think it's better to return IRQ_NONE,
as we do in other cases where there's no interrupt pending.  This will
facilitate refactoring the loop in pcie_isr(): we'll be able to call the
ISR in a loop as long as it returns IRQ_HANDLED.

Return IRQ_NONE if we couldn't read interrupt status.
Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

We create a procfs directory for every PCI bus.  Previously, the directory
name was just the bus number, so using the same bus number in different
domains caused a kernel crash when we tried to create a duplicate
directory.

Make pci_proc_domain() return the domain number, so procfs directories for
buses in domain 0 are named with just the bus number, and directories for
buses in other domains include both the domain number and the bus number.

[bhelgaas: changelog]
Signed-off-by: Bharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>

Dispose of virtual IRQ being created for MSI interrupts.
Signed-off-by: Bharat Kumar Gogada <bharatku@xilinx.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>