If we issue a hotplug command, go do something else, then come back and
wait for the command to complete, we don't have to wait the whole timeout
period, because some of it elapsed while we were doing something else.

Keep track of the time we issued the command, and wait only until the
timeout period from that point has elapsed.

For controllers with errata like Intel CF118, we previously timed out
before issuing the second hotplug command:

  At time T1 (during boot):
    - Write DLLSCE, ABPE, PDCE, etc. to Slot Control
  At time T2 (hotplug event):
    - Wait for command completion (CC) in Slot Status
    - Timeout at T2 + 1 second because CC is never set in Slot Status
    - Write PCC, PIC, etc. to Slot Control

With this change, we wait until T1 + 1 second instead of T2 + 1 second.
If the hotplug event is more than 1 second after the boot-time
initialization, we won't wait for the timeout at all.

We still emit a "Timeout on hotplug command" message if it timed out; we
should see this on the first hotplug event on every controller with this
erratum, as well as on real errors on controllers without the erratum.

Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e7-v2-spec-update.html
Tested-by: Rajat Jain <rajatxjain@gmail.com>	(IDT 807a controller)
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

Previously we issued a hotplug command and waited for it to complete.  But
there's no need to wait until we're ready to issue the *next* command.  The
next command will probably be much later, so the first one may have already
completed and we may not have to actually wait at all.

Because of hardware errata, some controllers generate command completion
events for some commands but not others.  In the case of Intel CF118 (see
spec update reference), the controller indicates command completion only
for Slot Control writes that change the value of the following bits:

  Power Controller Control
  Power Indicator Control
  Attention Indicator Control
  Electromechanical Interlock Control

Changes to other bits, e.g., the interrupt enable bits, do not cause the
Command Completed bit to be set.  Controllers from AMD and Nvidia are
reported to have similar errata.

These errata cause timeouts when pcie_enable_notification() enables
interrupts.  Previously that timeout occurred at boot-time.  With this
change, the timeout occurs later, when we change the state of the slot
power, indicators, or interlock.  This speeds up boot but causes a timeout
at the first hotplug event on the slot.  Subsequent events don't timeout
because only the first (boot-time) hotplug command updates Slot Control
without touching the power/indicator/interlock controls.

Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e7-v2-spec-update.html
Tested-by: Rajat Jain <rajatxjain@gmail.com>	(IDT 807a controller)
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

pcie_wait_cmd() waits for the controller to finish a hotplug command.  Move
the associated logic (to determine whether waiting is required and whether
we're using interrupts or polling) from pcie_write_cmd() to
pcie_wait_cmd().

No functional change.

Tested-by: Rajat Jain <rajatxjain@gmail.com>	(IDT 807a controller)
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>

pciehp assumes that dev->subordinate exists.  But we do not assign a bus if
we run out of bus numbers during enumeration.  This leads to a NULL
dereference in init_slot() (and other places).

Change pciehp_probe() to return -ENODEV when no subordinate bus is present.
Signed-off-by: NAndreas Noever <andreas.noever@gmail.com>
Signed-off-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>

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>

There is otherwise a risk of a null pointer dereference.

Found by cppcheck, a static code analysis program.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
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>

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>

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>

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>

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>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When a new device is added below a hotplug bridge, the bridge's secondary
bus speed and the device's bus speed must match.  The shpchp driver
previously checked the bridge's *primary* bus speed, not the secondary bus
speed.

This caused hot-add errors like:

  shpchp 0000:00:03.0: Speed of bus ff and adapter 0 mismatch

Check the secondary bus speed instead.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75251
Fixes: 3749c51a ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: NMarcel Apfelbaum <marcel.a@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
CC: stable@vger.kernel.org	# v2.6.34+

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>

Numerical values stored in the device tree are encoded in Big Endian and
should be byte swapped when running in Little Endian.

The RPA hotplug module should convert those values as well.

Note that in rpaphp_get_drc_props(), the comparison between indexes[i+1]
and *index is done using the BE values (whatever is the current endianess).
This doesn't matter since we are checking for equality here.  This way only
the returned value is byte swapped.

RPA also made RTAS calls which implies BE values to be used.  According to
the patch done in RTAS (http://patchwork.ozlabs.org/patch/336865), no
additional conversion is required in RPA.
Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

In case of a spurious "cmd completed", pcie_write_cmd() does not clear it,
but yet expects more "cmd completed" events to be generated.  This does not
happen because the previous (spurious) event has not been acknowledged.
Fix that.
Signed-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
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>

Use PCI_EXP_SLTCAP_PSN to make it easier to find code that uses the
Physical Slot Number field in the PCIe Slot Capabilities register.

No functional change.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Every pci_dev is on a valid pci_bus, so we don't need to test whether
dev->bus is NULL or not.

The only exceptions are a few legacy cases like alpha_core_agp_setup(),
parisc_agp_setup(), and megaraid's make_local_pdev(), where we allocate a
pci_dev with a NULL bus pointer.  These are dubious uses (especially the
megaraid one), and I don't think it's possible to exercise this
pci_configure_slot() path with any of them.

Found by Coverity (CID 146446).
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>

Minor whitespace cleanup; no functional change.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

In case a card is physically yanked out, it should immediately be removed,
regardless of the "surprise" capability bit. Thus:

  - Always handle the physical removal - regardless of the "surprise" bit.
  - Don't use "surprise" capability when making decisions about enabling
    presence detect notifications.
  - Reword the comments to indicate the intent.
Signed-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.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>

If we found device already exists during hot add device, we should leave
it, not turn the slot off.
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

This is a static checker fix and I can't test it, but from the context it
definitely looks like hexadecimal 0x20 was intended here instead of decimal
20.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

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>

Today it is there is no protection around pciehp_enable_slot() and
pciehp_disable_slot() to ensure that they complete before another
hot-plug operation can be done on that particular slot.

This patch introduces the slot->hotplug_lock to ensure that any hotplug
operations (add / remove) complete before another hotplug event can begin
processing on that particular slot.
Signed-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Today, this is how all the hotplug and unplug events work:

Hotplug / Removal needs to be done
  => Set slot->state (protected by slot->lock) to either
    POWERON_STATE (for enabling) or POWEROFF_STATE (for disabling).
  => Submit the work item for pciehp_power_thread() to slot->wq.

Problem:
  There is a problem if the hotplug events can happen fast enough that
  they do not give SW enough time to add or remove the new devices.

  => Assume: Event for unplug comes (e.g. surprise removal). But
     before the pciehp_power_thread() work item was executed, the
     card was replaced by another card, causing surprise hotplug event.

  => What goes wrong:
    => The hot-removal event sets slot->state to POWEROFF_STATE, and
       schedules the pciehp_power_thread().
    => The hot-add event sets slot->state to POWERON_STATE, and
       schedules the pciehp_power_thread().
    => Now the pciehp_power_thread() is scheduled twice, and on both
       occasions it will find POWERON_STATE and will try to add the
       devices on the slot, and will fail complaining that the devices
       already exist.

  => Why this is a problem: If the device was replaced between the hot
     removal and hot-add, then we should unload the old driver and
     reload the new one. This does not happen today. The kernel or the
     driver is not even aware that the device was replaced.

     The problem is that the pciehp_power_thread() only looks at the
     slot->state which would only contain the *latest* state - not
     the actual event (add / remove) that was the intent of the IRQ
     handler who submitted the work.

What this patch does:

  => Hotplug events pass on an actual request (for addition or removal)
     to pciehp_power_thread() which is local to that work item
     submission.

  => pciehp_power_thread() does not need to look at slote->state and
     hence no locks needed in that.

  => Essentially this results in all the hotplug and unplug events
     "replayed" by pciehp_power_thread().
Signed-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Disable the link notification (in addition to presence detect
notifications) across the slot reset since the reset could flap the link,
and we don't want to treat it as hot unplug followed by a hotplug.
Signed-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

It does not make much sense to refuse to disable a slot if an adapter is
not present or the latch is open. If an adapter is not present, it provides
an even better reason to disable the device slot.

This is specially a problem for link state hot-plug, because some ports use
in band mechanism for presence detection. Thus when link goes down,
presence detect also goes down. We _want_ that the removal should take
place in such case.

Thus remove the checks for adapter and latch in pciehp_disable_slot()
Signed-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

We need future link up events for hot-add, thus don't disable the link
permanently during device removal. Also, remove the static functions that
are now left unused.

This reverts part of 2debd928 ("PCI: pciehp: Disable/enable link during
slot power off/on").  This was discussed at the URL below, where it was
revealed that it was done for a bug in a PCIe repeater chip on that
particular platform.

Link: https://lkml.kernel.org/r/CAErSpo72KZ-a2OSQLWoK71GCgwBt676XZdGt4tEYm-6UYnLmPw@mail.gmail.comSigned-off-by: NRajat Jain <rajatxjain@gmail.com>
Signed-off-by: NRajat Jain <rajatjain@juniper.net>
Signed-off-by: NGuenter Roeck <groeck@juniper.net>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>