HP 6730b laptop has an ethernet NIC connected to one of the PCIe root
ports.  The root ports themselves are native PCIe hotplug capable.  Now,
during boot after PCI devices are scanned the BIOS triggers ACPI bus check
directly to the NIC:

  ACPI: \_SB_.PCI0.RP06.NIC_: Bus check in hotplug_event()

It is not clear why it is sending bus check but regardless the ACPI hotplug
notify handler calls enable_slot() directly (instead of going through
acpiphp_check_bridge() as there is no bridge), which ends up handling
special case for non-hotplug bridges with native PCIe hotplug.  This
results a crash of some kind but the reporter only sees black screen so it
is hard to figure out the exact spot and what actually happens.  Based on
a few fix proposals it was tracked to crash somewhere inside
pci_assign_unassigned_bridge_resources().

In any case we should not really be in that special branch at all because
the ACPI notify happened to a slot that is not a PCI bridge (it is just a
regular PCI device).

Fix this so that we only go to that special branch if we are calling
enable_slot() for a bridge (e.g., the ACPI notification was for the
bridge).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=201127
Fixes: 84c8b58e ("ACPI / hotplug / PCI: Don't scan bridges managed by native hotplug")
Reported-by: NPeter Anemone <peter.anemone@gmail.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: stable@vger.kernel.org	# v4.18+

When a PCI device is detected, pdev->is_added is set to 1 and proc and
sysfs entries are created.

When the device is removed, pdev->is_added is checked for one and then
device is detached with clearing of proc and sys entries and at end,
pdev->is_added is set to 0.

is_added and is_busmaster are bit fields in pci_dev structure sharing same
memory location.

A strange issue was observed with multiple removal and rescan of a PCIe
NVMe device using sysfs commands where is_added flag was observed as zero
instead of one while removing device and proc,sys entries are not cleared.
This causes issue in later device addition with warning message
"proc_dir_entry" already registered.

Debugging revealed a race condition between the PCI core setting the
is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue
setting the is_busmaster bit in pci_set_master().  As these fields are not
handled atomically, that clears the is_added bit.

Move the is_added bit to a separate private flag variable and use atomic
functions to set and retrieve the device addition state.  This avoids the
race because is_added no longer shares a memory location with is_busmaster.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283Signed-off-by: NHari Vyas <hari.vyas@broadcom.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLukas Wunner <lukas@wunner.de>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>

Remove unnecessary parentheses.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Following PCIehp mark the unplugged PCI devices disconnected.  This makes
sure PCI core code leaves the now missing hardware registers alone.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

When acpiphp re-enumerates a PCI hierarchy because of an ACPI Notify()
event, we should skip bridges managed by native hotplug (pciehp or shpchp).
We don't want to scan below a native hotplug bridge until the hotplug
controller generates a hot-add event.

A typical scenario is a Root Port leading to a Thunderbolt host router that
remains powered off until something is connected to it.  See [1] for the
lspci details.

  1. Before something is connected, only the Root Port exists.  It has
     PCI_EXP_SLTCAP_HPC set and pciehp is responsible for hotplug:

       00:1b.0 Root Port (HotPlug+)

  2. When a USB-C or Thunderbolt device is connected, the Switch in the
     Thunderbolt host router is powered up, the Root Port signals a hotplug
     add event and pciehp enumerates the Switch:

       01:00.0 Switch Upstream Port   to [bus 02-39]
       02:00.0 Switch Downstream Port to [bus 03]    (HotPlug-, to NHI)
       02:01.0 Switch Downstream Port to [bus 04-38] (HotPlug+, to Thunderbolt connector)
       02:02.0 Switch Downstream Port to [bus 39]    (HotPlug-, to xHCI)

     The 02:00.0 and 02:02.0 Ports lead to Endpoints that are not powered
     up yet.  The Ports have PCI_EXP_SLTCAP_HPC cleared, so pciehp doesn't
     handle hotplug for them and we assign minimal resources to them.

     The 02:01.0 Port has PCI_EXP_SLTCAP_HPC set, so pciehp handles native
     hotplug events for it.

  3. The BIOS powers up the xHCI controller.  If a Thunderbolt device was
     connected (not just a USB-C device), it also powers up the NHI.  Then
     it sends an ACPI Notify() to the Root Port, and acpiphp enumerates the
     new device(s):

       03:00.0 Thunderbolt Host Controller (NHI) Endpoint
       39:00.0 xHCI Endpoint

  4. If a Thunderbolt device was connected, the host router firmware uses
     the NHI to set up Thunderbolt tunnels and triggers a native hotplug
     event (via 02:01.0 in this example).  Then pciehp enumerates the new
     Thunderbolt devices:

       04:00.0 Switch Upstream Port   to [bus 05-38]
       05:01.0 Switch Downstream Port to [bus 06-09] (HotPlug-)
       05:04.0 Switch Downstream Port to [bus 0a-38] (HotPlug+)

     In this example, 05:01.0 leads to another Switch and some NICs.  This
     subtree is static, so 05:01.0 doesn't support hotplug and has
     PCI_EXP_SLTCAP_HPC cleared.

In step 3, acpiphp previously enumerated everything below the Root Port,
including things below the 02:01.0 Port.  We don't want that because pciehp
expects to manage hotplug below that Port, and firmware on the host router
may be in the middle of configuring its Link so it may not be ready yet.

To make this work better with the native PCIe (pciehp) and standard PCI
(shpchp) hotplug drivers, we let them handle all slot management and
resource allocation for hotplug bridges and restrict ACPI hotplug to
non-hotplug bridges.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=199581#c5
Link: https://lkml.kernel.org/r/20180529160155.1738-1-mika.westerberg@linux.intel.comSigned-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: changelog, use hotplug_is_native() instead of
dev->is_hotplug_bridge]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

Mike Lothian reported that plugging in a USB-C device does not work
properly in his Dell Alienware system.  This system has an Intel Alpine
Ridge Thunderbolt controller providing USB-C functionality.  In these
systems the USB controller (xHCI) is hotplugged whenever a device is
connected to the port using ACPI-based hotplug.

The ACPI description of the root port in question is as follows:

  Device (RP01)
  {
      Name (_ADR, 0x001C0000)

      Device (PXSX)
      {
          Name (_ADR, 0x02)

          Method (_RMV, 0, NotSerialized)
          {
              // ...
          }
      }

Here _ADR 0x02 means device 0, function 2 on the bus under root port (RP01)
but that seems to be incorrect because device 0 is the upstream port of the
Alpine Ridge PCIe switch and it has no functions other than 0 (the bridge
itself).  When we get ACPI Notify() to the root port resulting from
connecting a USB-C device, Linux tries to read PCI_VENDOR_ID from device 0,
function 2 which of course always returns 0xffffffff because there is no
such function and we never find the device.

In Windows this works fine.

Now, since we get ACPI Notify() to the root port and not to the PXSX device
we should actually start our scan from there as well and not from the
non-existent PXSX device.  Fix this by checking presence of the slot itself
(function 0) if we fail to do that otherwise.

While there use pci_bus_read_dev_vendor_id() in get_slot_status(), which is
the recommended way to read Device and Vendor IDs of devices on PCI buses.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198557Reported-by: NMike Lothian <mike@fireburn.co.uk>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org

Add SPDX GPL-2.0+ to all PCI files that specified the GPL and allowed
either GPL version 2 or any later version.

Remove the boilerplate GPL version 2 or later language, relying on the
assertion in b2441318 ("License cleanup: add SPDX GPL-2.0 license
identifier to files with no license") that the SPDX identifier may be used
instead of the full boilerplate text.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Per ebfdc409 ("checkpatch: attempt to find unnecessary 'out of memory'
messages"), when a memory allocation fails, the memory subsystem emits
generic "out of memory" messages (see slab_out_of_memory() for some of this
logging).  Therefore, additional error messages in the caller don't add
much value.

Remove messages that merely report "out of memory".

This preserves some messages that report additional information, e.g.,
allocation failures that mean we drop hotplug events.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
[bhelgaas: changelog, squash patches, make similar changes to acpiphp,
cpqphp, ibmphp, keep warning when dropping hotplug event]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The following pattern is often used:

  list_for_each_entry(dev, &bus->devices, bus_list) {
    if (pci_is_bridge(dev)) {
      ...
    }
  }

Add a for_each_pci_bridge() helper to make that code easier to write and
read by reducing indentation level.  It also saves one or few lines of code
in each occurrence.

Convert PCI core parts here at the same time.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[bhelgaas: fold in http://lkml.kernel.org/r/20171013165352.25550-1-andriy.shevchenko@linux.intel.com]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

We're about to add runtime PM of hotplug ports, but we need to restrict it
to ports that are handled natively by the OS:  If they're handled by the
firmware (which is the case for Thunderbolt on non-Macs), things would
break if the OS put the ports into D3hot behind the firmware's back.

To determine if a hotplug port is handled natively, one has to walk up from
the port to the root bridge and check the cached _OSC Control Field for the
value of the "PCI Express Native Hot Plug control" bit.  There's already a
function to do that, device_is_managed_by_native_pciehp(), but it's private
to drivers/pci/hotplug/acpiphp_glue.c and only compiled in if
CONFIG_HOTPLUG_PCI_ACPI is enabled.

Make it public and move it to drivers/pci/pci-acpi.c, so that it is
available in the more general CONFIG_ACPI case.

The function contains a check if the device in question is a hotplug port
and returns false if it's not.  The caller we're going to add doesn't need
this as it only calls the function if it actually *is* a hotplug port.
Move the check out of the function into the single existing caller.

Rename it to pciehp_is_native() and add some kerneldoc and polish.

No functional change intended.
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We cache the PCI_EXP_SLTCAP_HPC bit in pci_dev->is_hotplug_bridge on device
probe, so there's no need to read it again when adding the ACPI hotplug
context.

Here's the call chain to prove that no ordering issue is introduced:

pci_scan_child_bus [drivers/pci/probe.c]
  pci_scan_slot
    pci_scan_single_device
      pci_scan_device
        pci_setup_device
          set_pcie_hotplug_bridge
            [is_hotplug_bridge bit is set here]
  pci_scan_bridge
    pci_add_new_bus
      pci_alloc_child_bus
        pcibios_add_bus  [arch/(x86|arm64|ia64)/...]
          acpi_pci_add_bus [drivers/pci/pci-acpi.c]
            acpiphp_enumerate_slots [drivers/pci/hotplug/acpiphp_glue.c]
              acpiphp_add_context
                device_is_managed_by_native_pciehp
                  [is_hotplug_bridge bit is queried here]

No functional change intended.
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If a PCI bridge (or PCIe port) that is runtime-suspended gets an ACPI
hotplug notification, such as a bus check, it has to be resumed before
re-scanning the devices below it, or those devices will not be
accessible and will be treated as hot-removed.

Make that happen and let the bridge suspend again after the bus below it
has been re-scanned.

This is a replacement for commit 16468c78 ("ACPI / hotplug / PCI:
Runtime resume bridge before rescan") that has been reverted, because it
introduced a system resume regression (due to missing bridge->pci_dev
checks that are necessary in case the notification is targeted at the
host bridge) and it is necessary for the code added by commit
006d44e4 ("PCI: Add runtime PM support for PCIe ports") to work as
expected.
Tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 16468c78.

Bisection showed that it was the root cause for a resume hang on a
bog-standard all-Intel laptop (Sony Vaio Pro 11), and reverting fixes
the hang.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a PCI bridge (or PCIe port) that is runtime suspended gets an ACPI
hotplug event, such as BUS_CHECK we need to make sure it is resumed before
devices below the bridge are re-scanned. Otherwise the devices behind the
port are not accessible and will be treated as hot-unplugged.

To fix this, resume PCI bridges from runtime suspend while rescanning.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In acpiphp_enable_slot(), there is a missing unlock path
when error occurred.  It needs to be unlocked before returning
an error.
Signed-off-by: NInsu Yun <wuninsu@gmail.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix all whitespace issues (missing or needed whitespace) in all files in
drivers/pci.  Code is compiled with allyesconfig before and after code
changes and objects are recorded and checked with objdiff and they are not
changed after this commit.
Signed-off-by: NBogicevic Sasa <brutallesale@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

If the ignore_hotplug flag is set for a PCI device without an ACPI
companion and a bus check notification is received for an ancestor bridge
that is not the device's parent, ACPIPHP will ignore that flag.

Namely, in that case acpiphp_check_bridge() is called for the target bridge
and if all of the devices immediately below the bridge are still present,
trim_stale_devices() will be called for each of them.  That function
recursively walks the hierarchy downwards and removes device objects
corresponding to devices that don't appear to be present any more.
Unfortunately, it only checks ignore_hotplug for devices having ACPI
companions, so it will remove the others (if they don't respond) regardless
of the ignore_hotplug value.

Fix the problem by making trim_stale_devices() take ignore_hotplug into
consideration regardless of whether or not an ACPI companion is present for
the device it has been called for.

[bhelgaas: This may fix bug 61891, depending on whether the bridge above a
device is removed along with the device]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=61891Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

We now configure each PCI device as it is enumerated, in pci_device_add(),
so remove the configuration done in acpiphp.

That configuration, in pci_configure_device(), does not include the
MPS/MRRS configuration done by pcie_bus_configure_settings(), so keep
that here.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

Powering off a hot-pluggable device, e.g., with pci_set_power_state(D3cold),
normally generates a hot-remove event that unbinds the driver.

Some drivers expect to remain bound to a device even while they power it
off and back on again.  This can be dangerous, because if the device is
removed or replaced while it is powered off, the driver doesn't know that
anything changed.  But some drivers accept that risk.

Add pci_ignore_hotplug() for use by drivers that know their device cannot
be removed.  Using pci_ignore_hotplug() tells the PCI core that hot-plug
events for the device should be ignored.

The radeon and nouveau drivers use this to switch between a low-power,
integrated GPU and a higher-power, higher-performance discrete GPU.  They
power off the unused GPU, but they want to remain bound to it.

This is a reimplementation of f244d8b6 ("ACPIPHP / radeon / nouveau:
Fix VGA switcheroo problem related to hotplug") but extends it to work with
both acpiphp and pciehp.

This fixes a problem where systems with dual GPUs using the radeon drivers
become unusable, freezing every few seconds (see bugzillas below).  The
resume of the radeon device may also fail, e.g.,

This fixes problems on dual GPU systems where the radeon driver becomes
unusable because of problems while suspending the device, as in bug 79701:

    [drm] radeon: finishing device.
    radeon 0000:01:00.0: Userspace still has active objects !
    radeon 0000:01:00.0: ffff8800cb4ec288 ffff8800cb4ec000 16384 4294967297 force free
    ...
    WARNING: CPU: 0 PID: 67 at /home/apw/COD/linux/drivers/gpu/drm/radeon/radeon_gart.c:234 radeon_gart_unbind+0xd2/0xe0 [radeon]()
    trying to unbind memory from uninitialized GART !

or while resuming it, as in bug 77261:

    radeon 0000:01:00.0: ring 0 stalled for more than 10158msec
    radeon 0000:01:00.0: GPU lockup ...
    radeon 0000:01:00.0: GPU pci config reset
    pciehp 0000:00:01.0:pcie04: Card not present on Slot(1-1)
    radeon 0000:01:00.0: GPU reset succeeded, trying to resume
    *ERROR* radeon: dpm resume failed
    radeon 0000:01:00.0: Wait for MC idle timedout !

Link: https://bugzilla.kernel.org/show_bug.cgi?id=77261
Link: https://bugzilla.kernel.org/show_bug.cgi?id=79701Reported-by: NShawn Starr <shawn.starr@rogers.com>
Reported-by: NJose P. <lbdkmjdf@sharklasers.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Acked-by: NRajat Jain <rajatxjain@gmail.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NDave Airlie <airlied@redhat.com>
CC: stable@vger.kernel.org	# v3.15+

Fixes the following sparse warning:

drivers/pci/hotplug/acpiphp_glue.c:923:6: warning:
 symbol 'acpiphp_drop_bridge' was not declared. Should it be static?
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since all of the acpi_set_hp_context() callers pass at least one NULL
function pointer and one caller passes NULL function pointers only
to it, drop function pointer arguments from acpi_set_hp_context()
and make the callers initialize the function pointers in struct
acpi_hotplug_context by themselves before passing it to
acpi_set_hp_context().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

Since acpiphp_dev_to_bridge() is only called by
acpiphp_check_host_bridge(), move the code from it to that function
directly which reduces the call chain depth and makes the code
slightly easier to follow.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

After relatively recent changes in the ACPI-based PCI hotplug
(ACPIPHP) code, the acpiphp_check_host_bridge() executed for PCI
host bridges via acpi_pci_root_scan_dependent() doesn't do anything
useful, because those bridges do not have hotplug contexts.  That
happens by mistake, so fix it by making acpiphp_enumerate_slots()
add hotplug contexts to PCI host bridges too and modify
acpiphp_remove_slots() to drop those contexts for host bridges
as appropriate.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=76901
Fixes: 2d8b1d56 (ACPI / hotplug / PCI: Get rid of check_sub_bridges())
Reported-and-tested-by: NGavin Guo <gavin.guo@canonical.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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>

Use pci_is_bridge() to simplify code.  No functional change.

Requires: 326c1cda PCI: Rename pci_is_bridge() to pci_has_subordinate()
Requires: 1c86438c PCI: Add new pci_is_bridge() interface
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Some PCI functions used to be marked __devinit.  When CONFIG_HOTPLUG was
not set, these functions were discarded after boot.  A few callers of these
__devinit functions were marked __ref to indicate that they could safely
call the __devinit functions even though the callers were not __devinit.

But CONFIG_HOTPLUG and __devinit are now gone, and the need for the __ref
annotations is also gone, so remove them.  Relevant historical commits:

  54b956b9 Remove __dev* markings from init.h
  a8e4b9c1 PCI: add generic pci_hp_add_bridge()
  0ab2b57f PCI: fix section mismatch warning in pci_scan_child_bus
  451124a7 PCI: fix 4x section mismatch warnings
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

None of these files are actually using any __init type directives and hence
don't need to include <linux/init.h>.   Most are just a left over from
__devinit and __cpuinit removal, or simply due to code getting copied from
one driver to the next.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Make the ACPI-based PCI hotplug (ACPIPHP) code use
pci_device_is_present() for checking if devices are present instead
of open coding the same thing.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>

In order to avoid the need to register special ACPI dock
operations for SATA devices add a .uevent() callback pointer to
struct acpi_hotplug_context and make dock_hotplug_event() use that
callback if available.  Also rename the existing .event() callback
in struct acpi_hotplug_context to .notify() to avoid possible
confusion in the future.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of requiring a set of special dock operations to be registered
via register_hotplug_dock_device() for each ACPI dock device, it is
much more straightforward to use callback pointers from the devices'
hotplug contexts if available.

For this reason, modify dock_hotplug_event() to use callback pointers
from the hotplug contexts of ACPI devices and fall back to using the
special dock operarions only if those callbacks are missing.  Also
make the ACPI-based PCI hotplug (ACPIPHP) subsystem set the .fixup
callback pointer in the hotplug contexts of devices handled by it to
a new function, acpiphp_post_dock_fixup(), so that the dock station
driver can use the callbacks from those contexts instead of special
dock operations registered via register_hotplug_dock_device().

Along with the above changes drop the ACPIPHP's dock operations that
are not necessary any more.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Rework the ACPI dock station driver to store ACPI device object
pointers instead of ACPI handles in its internal data structures.

The purpose is moslty to make subsequent simplifications possible,
but also this allows the overall code size to be reduced slightly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In order for the ACPI dock station code to be able to use the
callbacks pointed to by the ACPI device objects' hotplug contexts
add a .fixup() callback pointer to struct acpi_hotplug_context.
That callback will be useful to handle PCI devices located in
dock stations.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

After recent changes adding dock station handling to the ACPI hotplug
core, it is not necessary to clear the .event() pointer in the
ACPIPHP device hotplug context for dock stations any more, so don't
do that.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, ACPIPHP does not add hotplug context to devices that
should be handled by the native PCI hotplug (PCIeHP) code.  The
reason why was because PCIeHP didn't know about the devices'
connections with ACPI and would not clean up things properly
during an eject of an ACPI-backed device, for example.

However, after recent changes that made the ACPI core create struct
acpi_device objects for all namespace nodes regardless of the
underlying devices' status and added PCI rescan-remove locking to
both ACPIPHP and PCIeHP, that concern is not valid any more.
Namely, after those changes PCIeHP need not care about the ACPI
side of things any more and it should be serialized with respect to
ACPIPHP and they won't be running concurrently with each other in
any case.

For this reason, make ACPIPHP to add its hotplug context to
all devices with ACPI companions, even the ones that should be
handled by PCIeHP in principle.  That may work around hotplug
issues on some systems where PCIeHP is supposed to work, but it
doesn't and the ACPI hotplug signaling works instead.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The name of register_slot() doesn't really reflect what the function
is does, so rename it to acpiphp_add_context() and add a proper
kerneldoc comment to it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace list_for_each() + pci_bus_b() with list_for_each_entry().
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>

The ACPI specification (ACPI 5.0A, Section 6.3.7) says:

 _STA may return bit 0 clear (not present) with bit 3 set (device is
 functional). This case is used to indicate a valid device for which
 no device driver should be loaded (for example, a bridge device.)
 Children of this device may be present and valid. OSPM should
 continue enumeration below a device whose _STA returns this bit
 combination.

Evidently, some BIOSes follow that and return 0x0A from _STA, which
causes problems to happen when they trigger bus check or device check
notifications for those devices too.  Namely, ACPIPHP thinks that they
are gone and may drop them, for example, if such a notification is
triggered during a resume from system suspend.

To fix that, modify ACPICA to regard devies as present and
functioning if _STA returns both the ACPI_STA_DEVICE_ENABLED
and ACPI_STA_DEVICE_FUNCTIONING bits set for them.
Reported-and-tested-by: NPeter Wu <lekensteyn@gmail.com>
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
[rjw: Subject and changelog, minor code modifications]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since acpi_device_hotplug() assumes that ACPI handles of device
objects passed to it will not become invalid while acpi_scan_lock
is being held, make acpiphp_disable_slot() acquire acpi_scan_lock,
because it generally causes _EJ0 to be executed for one of the
devices in the slot and that may cause its ACPI handle to become
invalid.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since the only existing caller of acpiphp_check_host_bridge(),
which is acpi_pci_root_scan_dependent(), already has a struct
acpi_device pointer needed to obtain the ACPIPHP context, it
doesn't make sense to execute acpi_bus_get_device() on its
handle in acpiphp_handle_to_bridge() just in order to get that
pointer back.

For this reason, modify acpiphp_check_host_bridge() to take
a struct acpi_device pointer as its argument and rearrange the
code accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Since acpi_bus_notify() is executed on all notifications for all
devices anyway, make it execute acpi_device_hotplug() for all
hotplug events instead of installing notify handlers pointing to
the same function for all hotplug devices.

This change reduces both the size and complexity of ACPI-based device
hotplug code.  Moreover, since acpi_device_hotplug() only does
significant things for devices that have either an ACPI scan handler,
or a hotplug context with .eject() defined, and those devices
had notify handlers pointing to acpi_hotplug_notify_cb() installed
before anyway, this modification shouldn't change functionality.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>