The motivation for this change is to provide a way to work around
a problem with the direct-complete mechanism used for avoiding
system suspend/resume handling for devices in runtime suspend.

The problem is that some middle layer code (the PCI bus type and
the ACPI PM domain in particular) returns positive values from its
system suspend ->prepare callbacks regardless of whether the driver's
->prepare returns a positive value or 0, which effectively prevents
drivers from being able to control the direct-complete feature.
Some drivers need that control, however, and the PCI bus type has
grown its own flag to deal with this issue, but since it is not
limited to PCI, it is better to address it by adding driver flags at
the core level.

To that end, add a driver_flags field to struct dev_pm_info for flags
that can be set by device drivers at the probe time to inform the PM
core and/or bus types, PM domains and so on on the capabilities and/or
preferences of device drivers.  Also add two static inline helpers
for setting that field and testing it against a given set of flags
and make the driver core clear it automatically on driver remove
and probe failures.

Define and document two PM driver flags related to the direct-
complete feature: NEVER_SKIP and SMART_PREPARE that can be used,
respectively, to indicate to the PM core that the direct-complete
mechanism should never be used for the device and to inform the
middle layer code (bus types, PM domains etc) that it can only
request the PM core to use the direct-complete mechanism for
the device (by returning a positive value from its ->prepare
callback) if it also has been requested by the driver.

While at it, make the core check pm_runtime_suspended() when
setting power.direct_complete so that it doesn't need to be
checked by ->prepare callbacks.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

Some drivers (specifically the nes IB driver), want to create a lot of
sysfs driver attributes.  Instead of open-coding the creation and
removal of these files (and getting it wrong btw), it's a better idea to
let the driver core handle all of this logic for us.

So add a new field to the pci driver structure, **groups, that allows
pci drivers to specify an attribute group list it wishes to have created
when it is registered with the driver core.

Big bonus is now the driver doesn't race with userspace when the sysfs
files are created vs. when the kobject is announced, so any script/tool
that actually wanted to use these files will not have to poll waiting
for them to show up.

Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

PCI bridges only have a reason to generate wakeup signals on behalf
of devices below them, so avoid preparing bridges for wakeup directly
in pci_enable_wake().

Also drop the pci_has_subordinate() check from pci_pm_default_resume()
as this will be done by pci_enable_wake() itself now.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

Commit dc15e71e (PCI / PM: Restore PME Enable if skipping wakeup
setup) introduced a mechanism by which the PME Enable bit can be
restored by pci_enable_wake() if dev->wakeup_prepared is set in
case it has been overwritten by PCI config space restoration.

However, that commit overlooked the fact that on some systems (Dell
XPS13 9360 in particular) the AML handling wakeup events checks PME
Status and PME Enable and it won't trigger a Notify() for devices
where those bits are not set while it is running.

That happens during resume from suspend-to-idle when pci_restore_state()
invoked by pci_pm_default_resume_early() clears PME Enable before the
wakeup events are processed by AML, effectively causing those wakeup
events to be ignored.

Fix this issue by restoring the PME Enable configuration right after
pci_restore_state() has been called instead of doing that in
pci_enable_wake().

Fixes: dc15e71e (PCI / PM: Restore PME Enable if skipping wakeup setup)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

The pci_assign_irq() function allows assignment of an IRQ to devices during
device enable time rather than only at boot.  Therefore call it in the
pci_device_probe() function during the enable device code path so this
assignment can be performed.

This patch will do nothing on arches which do not set the IRQ mapping
function pointers and is therefore currently a nop, however as support for
these function pointers is added to arch-specific code this will cause IRQ
assignment to migrate to device enable time allowing the new code paths to
be used.
Signed-off-by: NMatthew Minter <matt@masarand.com>
[lorenzo.pieralisi@arm.com: moved pci_assign_irq() call site]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Currently we saw a lot of "No irq handler" errors during hibernation, which
caused the system hang finally:

  ata4.00: qc timeout (cmd 0xec)
  ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4)
  ata4.00: revalidation failed (errno=-5)
  ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
  do_IRQ: 31.151 No irq handler for vector

According to above logs, there is an interrupt triggered and it is
dispatched to CPU31 with a vector number 151, but there is no handler for
it, thus this IRQ will not get acked and will cause an IRQ flood which
kills the system.  To be more specific, the 31.151 is an interrupt from the
AHCI host controller.

After some investigation, the reason why this issue is triggered is because
the thaw_noirq() function does not restore the MSI/MSI-X settings across
hibernation.

The scenario is illustrated below:

  1. Before hibernation, IRQ 34 is the handler for the AHCI device, which
     is bound to CPU31.

  2. Hibernation starts, the AHCI device is put into low power state.

  3. All the nonboot CPUs are put offline, so IRQ 34 has to be migrated to
     the last alive one - CPU0.

  4. After the snapshot has been created, all the nonboot CPUs are brought
     up again; IRQ 34 remains bound to CPU0.

  5. AHCI devices are put into D0.

  6. The snapshot is written to the disk.

The issue is triggered in step 6.  The AHCI interrupt should be delivered
to CPU0, however it is delivered to the original CPU31 instead, which
causes the "No irq handler" issue.

Ying Huang has provided a clue that, in step 3 it is possible that writing
to the register might not take effect as the PCI devices have been
suspended.

In step 3, the IRQ 34 affinity should be modified from CPU31 to CPU0, but
in fact it is not.  In __pci_write_msi_msg(), if the device is already in
low power state, the low level MSI message entry will not be updated but
cached.  During the device restore process after a normal suspend/resume,
pci_restore_msi_state() writes the cached MSI back to the hardware.

But this is not the case for hibernation.  pci_restore_msi_state() is not
currently called in pci_pm_thaw_noirq(), although pci_save_state() has
saved the necessary PCI cached information in pci_pm_freeze_noirq().

Restore the PCI status for the device during hibernation.  Otherwise the
status might be lost across hibernation (for example, settings for MSI,
MSI-X, ATS, ACS, IOV, etc.), which might cause problems during hibernation.
Suggested-by: NYing Huang <ying.huang@intel.com>
Suggested-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NChen Yu <yu.c.chen@intel.com>
[bhelgaas: changelog]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org
Cc: Len Brown <len.brown@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: Ying Huang <ying.huang@intel.com>

After previous changes it is not necessary to distinguish between
device wakeup for run time and device wakeup from system sleep states
any more, so rework the PCI device wakeup settings code accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

We are trying to get rid of DRIVER_ATTR(), and all of the pci-driver
core driver attributes can be trivially changed to use DRIVER_ATTR_WO().

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: <linux-pci@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

pci_call_probe() can called recursively when a physcial function is probed
and the probing creates virtual functions, which are populated via
pci_bus_add_device() which in turn can end up calling pci_call_probe()
again.

The code has an interesting way to prevent recursing into the workqueue
code.  That's accomplished by a check whether the current task runs already
on the numa node which is associated with the device.

While that works to prevent the recursion into the workqueue code, it's
racy versus normal execution as there is no guarantee that the node does
not vanish after the check.

There is another issue with this code. It dereferences cpumask_of_node()
unconditionally without checking whether the node is available.

Make the detection reliable by:

 - Mark a probed device as 'is_probed' in pci_call_probe()
 
 - Check in pci_call_probe for a virtual function. If it's a virtual
   function and the associated physical function device is marked
   'is_probed' then this is a recursive call, so the call can be invoked in
   the calling context.

 - Add a check whether the node is online before dereferencing it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-pci@vger.kernel.org
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.771457199@linutronix.de

Converting the hotplug locking, i.e. get_online_cpus(), to a percpu rwsem
unearthed a circular lock dependency which was hidden from lockdep due to
the lockdep annotation of get_online_cpus() which prevents lockdep from
creating full dependency chains. There are several variants of this. And
example is:

Chain exists of:

cpu_hotplug_lock.rw_sem --> drm_global_mutex --> &item->mutex

CPU0                    CPU1
----                    ----
lock(&item->mutex);
                        lock(drm_global_mutex);
                        lock(&item->mutex);
lock(cpu_hotplug_lock.rw_sem);

because there are dependencies through workqueues. The call chain is:

	get_online_cpus
	apply_workqueue_attrs
	__alloc_workqueue_key
	ttm_mem_global_init
	ast_ttm_mem_global_init
	drm_global_item_ref
	ast_mm_init
	ast_driver_load
	drm_dev_register
	drm_get_pci_dev
	ast_pci_probe
	local_pci_probe
	work_for_cpu_fn
	process_one_work
	worker_thread

This is not a problem of get_online_cpus() recursion, it's a possible
deadlock undetected by lockdep so far.

The cure is to use cpu_hotplug_disable() instead of get_online_cpus() to
protect the PCI probing.

There is a side effect to this: cpu_hotplug_disable() makes a concurrent
cpu hotplug attempt via the sysfs interfaces fail with -EBUSY, but PCI
probing usually happens during the boot process where no interaction is
possible. Any later invocations are infrequent enough and concurrent
hotplug attempts are so unlikely that the danger of user space visible
regressions is very close to zero. Anyway, thats preferrable over a real
deadlock.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-pci@vger.kernel.org
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.691198590@linutronix.de

Sometimes it is not desirable to bind SR-IOV VFs to drivers.  This can save
host side resource usage by VF instances that will be assigned to VMs.

Add a new PCI sysfs interface "sriov_drivers_autoprobe" to control that
from the PF.  To modify it, echo 0/n/N (disable probe) or 1/y/Y (enable
probe) to:

  /sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_drivers_autoprobe

Note that this must be done before enabling VFs.  The change will not take
effect if VFs are already enabled.  Simply, one can disable VFs by setting
sriov_numvfs to 0, choose whether to probe or not, and then re-enable the
VFs by restoring sriov_numvfs.

[bhelgaas: changelog, ABI doc]
Signed-off-by: NBodong Wang <bodong@mellanox.com>
Signed-off-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>

The pci_bus_type .shutdown method, pci_device_shutdown(), is called from
device_shutdown() in the kernel restart and shutdown paths.

Previously, pci_device_shutdown() called pci_msi_shutdown() and
pci_msix_shutdown().  This disables MSI and MSI-X, which causes the device
to fall back to raising interrupts via INTx.  But the driver is still bound
to the device, it doesn't know about this change, and it likely doesn't
have an INTx handler, so these INTx interrupts cause "nobody cared"
warnings like this:

  irq 16: nobody cared (try booting with the "irqpoll" option)
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.2-1.el7_UNSUPPORTED.x86_64 #1
  Hardware name: Hewlett-Packard HP Z820 Workstation/158B, BIOS J63 v03.90 06/
  ...

The MSI disabling code was added by d52877c7 ("pci/irq: let
pci_device_shutdown to call pci_msi_shutdown v2") because a driver left MSI
enabled and kdump failed because the kexeced kernel wasn't prepared to
receive the MSI interrupts.

Subsequent commits 1851617c ("PCI/MSI: Disable MSI at enumeration even
if kernel doesn't support MSI") and  e80e7edc ("PCI/MSI: Initialize MSI
capability for all architectures") changed the kexeced kernel to disable
all MSIs itself so it no longer depends on the crashed kernel to clean up
after itself.

Stop disabling MSI/MSI-X in pci_device_shutdown().  This resolves the
"nobody cared" unhandled IRQ issue above.  It also allows PCI serial
devices, which may rely on the MSI interrupts, to continue outputting
messages during reboot/shutdown.

[bhelgaas: changelog, drop pci_msi_shutdown() and pci_msix_shutdown() calls
altogether]
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=187351Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Alex Williamson <alex.williamson@redhat.com>
CC: David Arcari <darcari@redhat.com>
CC: Myron Stowe <mstowe@redhat.com>
CC: Lukas Wunner <lukas@wunner.de>
CC: Keith Busch <keith.busch@intel.com>
CC: Mika Westerberg <mika.westerberg@linux.intel.com>

Function __pci_device_probe() tries to be careful about a PCI driver
probe() hook returning a positive value, but this is not really necessary,
since the same fix up is already done in local_pci_probe() (preceded by a
noisy warning), which renders this instance dead code.
Signed-off-by: NGabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Signed-off-by: NPhil Sutter <phil@nwl.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Drop the CONFIG_KEXEC_CORE #ifdef around reference to "kexec_in_progress".

Commit 2b94ed24 ("kexec: define kexec_in_progress in !CONFIG_KEXEC
case") has made this unnecessary.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Currently the Linux PCI core does not touch power state of PCI bridges and
PCIe ports when system suspend is entered.  Leaving them in D0 consumes
power unnecessarily and may prevent the CPU from entering deeper C-states.

With recent PCIe hardware we can power down the ports to save power given
that we take into account few restrictions:

  - The PCIe port hardware is recent enough, starting from 2015.

  - Devices connected to PCIe ports are effectively in D3cold once the port
    is transitioned to D3 (the config space is not accessible anymore and
    the link may be powered down).

  - Devices behind the PCIe port need to be allowed to transition to D3cold
    and back.  There is a way both drivers and userspace can forbid this.

  - If the device behind the PCIe port is capable of waking the system it
    needs to be able to do so from D3cold.

This patch adds a new flag to struct pci_device called 'bridge_d3'.  This
flag is set and cleared by the PCI core whenever there is a change in power
management state of any of the devices behind the PCIe port.  When system
later on is suspended we only need to check this flag and if it is true
transition the port to D3 otherwise we leave it in D0.

Also provide override mechanism via command line parameter
"pcie_port_pm=[off|force]" that can be used to disable or enable the
feature regardless of the BIOS manufacturing date.
Tested-by: NLukas Wunner <lukas@wunner.de>
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>

The runtime PM core doesn't treat EBUSY and EAGAIN retvals from the driver
suspend hooks as errors, but they still show up as errors in dmesg. Tune
them down. See rpm_suspend() for details of handling these return values.

Note that we use dev_dbg() for the retryable retvals, so after this
change you'll need either CONFIG_DYNAMIC_DEBUG or CONFIG_PCI_DEBUG
for them to show up in the log.

One problem caused by this was noticed by Daniel: the i915 driver
returns EAGAIN to signal a temporary failure to suspend and as a request
towards the RPM core for scheduling a suspend again. This is a normal
event, but the resulting error message flags a breakage during the
driver's automated testing which parses dmesg and picks up the error.
Reported-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: https://bugs.freedesktop.org/show_bug.cgi?id=92992Signed-off-by: NImre Deak <imre.deak@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is a concern that if the platform firmware was involved in
the system resume that's being completed,  some devices might have
been reset by it and if those devices had the power.direct_complete
flag set during the preceding suspend transition, they may stay
in a reset-power-on state indefinitely (until they are runtime-resumed
and then suspended again).  That may not be a big deal from the
individual device's perspective, but if the system is an SoC, it may
be prevented from entering deep SoC-wide low-power states on idle
because of that.

The devices that are most likely to be affected by this issue are
PCI devices and ACPI-enumerated devices using the general ACPI PM
domain, so to prevent it from happening for those devices, force a
runtime resume for them if they have their power.direct_complete
flags set and the platform firmware was involved in the resume
transition currently in progress.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The pm_request_idle() in pm_generic_complete() is pointless as it is
called with the runtime PM usage counter different from zero (bumped
up by the core during the prepare phase of system suspend) and the
core calls pm_runtime_put() for all devices after executing their
complete callbacks, so drop it.

This allows the PCI PM layer to use pm_generic_complete() too.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>

Commit bac2a909 (PCI / PM: Avoid resuming PCI devices during
system suspend) introduced a mechanism by which some PCI devices that
were runtime-suspended at the system suspend time might be left in
that state for the duration of the system suspend-resume cycle.
However, it overlooked devices that were marked as capable of waking
up the system just because PME support was detected in their PCI
config space.

Namely, in that case, device_can_wakeup(dev) returns 'true' for the
device and if the device is not configured for system wakeup,
device_may_wakeup(dev) returns 'false' and it will be resumed during
system suspend even though configuring it for system wakeup may not
really make sense at all.

To avoid this problem, simply disable PME for PCI devices that have
not been configured for system wakeup and are runtime-suspended at
the system suspend time for the duration of the suspend-resume cycle.

If the device is in D3cold, its config space is not available and it
shouldn't be written to, but that's only possible if the device
has platform PM support and the platform code is responsible for
checking whether or not the device's configuration is suitable for
system suspend in that case.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Section 3.2 "Device Runtime Power Management" of pci.txt has become
outdated, so update it to correctly reflect the current code flow.

Also update the comment in local_pci_probe() to document the fact
that pm_runtime_put_noidle() is not the only runtime PM helper
function that can be used to decrement the device's runtime PM
usage counter in .probe().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>

In store_remove_id(), set the default return value to -ENODEV, and
overwrite it with the input buffer size if we find a matching list entry.
Then we don't need to test whether to return an error or the count.

No functional change.

[bhelgaas: changelog]
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NDave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add pcibios_alloc_irq() and pcibios_free_irq(), which are called when
binding/unbinding PCI device drivers.

PCI arch code may implement these to manage IRQ resources for hotplugged
devices.

[bhelgaas: changelog]
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Commit f25c0ae2 (ACPI / PM: Avoid resuming devices in ACPI PM
domain during system suspend) modified the ACPI PM domain's system
suspend callbacks to allow devices attached to it to be left in the
runtime-suspended state during system suspend so as to optimize
the suspend process.

This was based on the general mechanism introduced by commit
aae4518b (PM / sleep: Mechanism to avoid resuming runtime-suspended
devices unnecessarily).

Extend that approach to PCI devices by modifying the PCI bus type's
->prepare callback to return 1 for devices that are runtime-suspended
when it is being executed and that are in a suitable power state and
need not be resumed going forward.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

Some implementations of modprobe fail to load the driver for a PCI device
automatically because the "interface" part of the modalias from the kernel
is lowercase, and the modalias from file2alias is uppercase.

The "interface" is the low-order byte of the Class Code, defined in PCI
r3.0, Appendix D.  Most interface types defined in the spec do not use
alpha characters, so they won't be affected.  For example, 00h, 01h, 10h,
20h, etc. are unaffected.

Print the "interface" byte of the Class Code in uppercase hex, as we
already do for the Vendor ID, Device ID, Class, etc.

Commit 89ec3dcf ("PCI: Generate uppercase hex for modalias interface
class") fixed only half of the problem.  Some udev implementations rely on
the uevent file and not the modalias file.

Fixes: d1ded203 ("PCI: add MODALIAS to hotplug event for pci devices")
Fixes: 89ec3dcf ("PCI: Generate uppercase hex for modalias interface class")
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: stable@vger.kernel.org

After commit b2b49ccb (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PCI core code.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The variable "retval" in pci_add_dynid() is only used to store the return
value of driver_attach() and is then directly returned.  Remove the
variable and directly pass on driver_attach()'s return value.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Add pci_fixup_suspend_late as a new pci_fixup_pass. The pass is called
from suspend_noirq and poweroff_noirq. Using the same pass for suspend
and hibernate is consistent with resume_early which is called by
resume_noirq and restore_noirq.

The new quirk pass is required for Thunderbolt support on Apple
hardware.
Signed-off-by: NAndreas Noever <andreas.noever@gmail.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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>

The driver_override field allows us to specify the driver for a device
rather than relying on the driver to provide a positive match of the
device.  This shortcuts the existing process of looking up the vendor and
device ID, adding them to the driver new_id, binding the device, then
removing the ID, but it also provides a couple advantages.

First, the above existing process allows the driver to bind to any device
matching the new_id for the window where it's enabled.  This is often not
desired, such as the case of trying to bind a single device to a meta
driver like pci-stub or vfio-pci.  Using driver_override we can do this
deterministically using:

  echo pci-stub > /sys/bus/pci/devices/0000:03:00.0/driver_override
  echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
  echo 0000:03:00.0 > /sys/bus/pci/drivers_probe

Previously we could not invoke drivers_probe after adding a device to
new_id for a driver as we get non-deterministic behavior whether the driver
we intend or the standard driver will claim the device.  Now it becomes a
deterministic process, only the driver matching driver_override will probe
the device.

To return the device to the standard driver, we simply clear the
driver_override and reprobe the device:

  echo > /sys/bus/pci/devices/0000:03:00.0/driver_override
  echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
  echo 0000:03:00.0 > /sys/bus/pci/drivers_probe

Another advantage to this approach is that we can specify a driver override
to force a specific binding or prevent any binding.  For instance when an
IOMMU group is exposed to userspace through VFIO we require that all
devices within that group are owned by VFIO.  However, devices can be
hot-added into an IOMMU group, in which case we want to prevent the device
from binding to any driver (override driver = "none") or perhaps have it
automatically bind to vfio-pci.  With driver_override it's a simple matter
for this field to be set internally when the device is first discovered to
prevent driver matches.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: NAlexander Graf <agraf@suse.de>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Previously, pci_is_bridge() returned true only when a subordinate bus
existed.  Rename pci_is_bridge() to pci_has_subordinate() to better
indicate what we're checking.

No functional change.

[bhelgaas: changelog]
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

"pdev" can never be NULL here, so remove the test.

Found by Coverity (CID 744313).
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

While using the sysfs new_id interface, the user can unintentionally feed
incorrect values if the driver static table has a matching entry.  This is
possible since only the device and vendor fields are mandatory and the rest
are optional.  As a result, store_new_id() will fill in default values that
are then passed on to the driver and can have unintended consequences.

As an example, consider the ixgbe driver and the 82599EB network card:

  echo "8086 10fb" > /sys/bus/pci/drivers/ixgbe/new_id

This will pass a pci_device_id with driver_data = 0 to ixgbe_probe(), which
uses that zero to index a table of card operations.  The zeroth entry of
the table does *not* correspond to the 82599 operations.

This change returns an error if the user attempts to add a dynid for a
vendor/device combination for which a static entry already exists.
However, if the user intentionally wants a different set of values, she
must provide all the 7 fields and that will be accepted.

[bhelgaas: drop KVM text since the problem isn't KVM-specific]
Signed-off-by: NBandan Das <bsd@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>

Runtime-suspended devices are resumed during system suspend by
pci_pm_prepare() for two reasons: First, because they may need
to be reprogrammed in order to change their wakeup settings and,
second, because they may need to be operatonal for their children
to be successfully suspended.  That is a problem, though, if there
are many runtime-suspended devices that need to be resumed this
way during system suspend, because the .prepare() PM callbacks of
devices are executed sequentially and the times taken by them
accumulate, which may increase the total system suspend time quite
a bit.

For this reason, move the resume of runtime-suspended devices up
to the next phase of device suspend (during system suspend), except
for the ones that have power.ignore_children set.  The exception is
made, because the devices with power.ignore_children set may still
be necessary for their children to be successfully suspended (during
system suspend) and they won't be resumed automatically as a result
of the runtime resume of their children.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

Add a flag to tell the PCI subsystem that kernel is shutting down in
preparation to kexec a kernel.  Add code in PCI subsystem to use this flag
to clear Bus Master bit on PCI devices only in case of kexec reboot.

This fixes a power-off problem on Acer Aspire V5-573G and likely other
machines and avoids any other issues caused by clearing Bus Master bit on
PCI devices in normal shutdown path.  The problem was introduced by
b566a22c ("PCI: disable Bus Master on PCI device shutdown").

This patch is based on discussion at
http://marc.info/?l=linux-pci&m=138425645204355&w=2

Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861Reported-by: NChang Liu <cl91tp@gmail.com>
Signed-off-by: NKhalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Cc: stable@vger.kernel.org	# v3.5+

If we are already on a CPU local to the device, call the driver .probe()
method directly without using work_on_cpu().

This is a workaround for a lockdep warning in the following scenario:

  pci_call_probe
    work_on_cpu(cpu, local_pci_probe, ...)
      driver .probe
        pci_enable_sriov
          ...
            pci_bus_add_device
              ...
                pci_call_probe
                  work_on_cpu(cpu, local_pci_probe, ...)

It would be better to fix PCI so we don't call VF driver .probe() methods
from inside a PF driver .probe() method, but that's a bigger project.

[bhelgaas: open bugzilla, rework comments & changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=65071
Link: http://lkml.kernel.org/r/CAE9FiQXYQEAZ=0sG6+2OdffBqfLS9MpoN1xviRR9aDbxPxcKxQ@mail.gmail.com
Link: http://lkml.kernel.org/r/20130624195942.40795.27292.stgit@ahduyck-cp1.jf.intel.comTested-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NYinghai Lu <yinghai@kernel.org>