To prepare for interrupt spreading reduce the storage size of
irq_info::spurious_cnt to u8 so the required flag for the spreading logic
will not increase the storage size.

Protect the usage site against overruns.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20201210194045.360198201@linutronix.de

All event channel setups bind the interrupt on CPU0 or the target CPU for
percpu interrupts and overwrite the affinity mask with the corresponding
cpumask. That does not make sense.

The XEN implementation of irqchip::irq_set_affinity() already picks a
single target CPU out of the affinity mask and the actual target is stored
in the effective CPU mask, so destroying the user chosen affinity mask
which might contain more than one CPU is wrong.

Change the implementation so that the channel is bound to CPU0 at the XEN
level and leave the affinity mask alone. At startup of the interrupt
affinity will be assigned out of the affinity mask and the XEN binding will
be updated. Only keep the enforcement for real percpu interrupts.

On resume the overwrite is not required either because info->cpu and the
affinity mask are still the same as at the time of suspend. Same for
rebind_evtchn_irq().

This also prepares for proper interrupt spreading.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20201210194045.250321315@linutronix.de

There is absolutely no reason to mimic the x86 deferred affinity
setting. This mechanism is required to handle the hardware induced issues
of IO/APIC and MSI and is not in use when the interrupts are remapped.

XEN does not need this and can simply change the affinity from the calling
context. The core code invokes this with the interrupt descriptor lock held
so it is fully serialized against any other operation.

Mark the interrupts with IRQ_MOVE_PCNTXT to disable the deferred affinity
setting. The conditional mask/unmask operation is already handled in
xen_rebind_evtchn_to_cpu().

This makes XEN on x86 use the same mechanics as on e.g. ARM64 where
deferred affinity setting is not required and not implemented and the code
path in the ack functions is compiled out.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20201210194045.157601122@linutronix.de

This function can only ever work when the event channels:

  - are already established
  - interrupts assigned to them
  - the affinity has been set by user space already

because any newly set up event channel is forced to be bound to CPU0 and
the affinity mask of the interrupt is forced to contain cpumask_of(0).

As the CPU0 enforcement was in place _before_ this was implemented it's
entirely unclear how that can ever have worked at all.

Remove it as preparation for doing it proper.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20201210194045.065115500@linutronix.de

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20201210194044.972064156@linutronix.de

Using the interrupt affinity mask for checking locality is not really
working well on architectures which support effective affinity masks.

The affinity mask is either the system wide default or set by user space,
but the architecture can or even must reduce the mask to the effective set,
which means that checking the affinity mask itself does not really tell
about the actual target CPUs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20201210194044.876342330@linutronix.de

No driver has any business with the internals of an interrupt
descriptor. Storing a pointer to it just to use yet another helper at the
actual usage site to retrieve the affinity mask is creative at best. Just
because C does not allow encapsulation does not mean that the kernel has no
limits.

Retrieve a pointer to the affinity mask itself and use that. It's still
using an interface which is usually not for random drivers, but definitely
less hideous than the previous hack.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20201210194044.769458162@linutronix.de

Using the interrupt affinity mask for checking locality is not really
working well on architectures which support effective affinity masks.

The affinity mask is either the system wide default or set by user space,
but the architecture can or even must reduce the mask to the effective set,
which means that checking the affinity mask itself does not really tell
about the actual target CPUs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20201210194044.672935978@linutronix.de

No driver has any business with the internals of an interrupt
descriptor. Storing a pointer to it just to use yet another helper at the
actual usage site to retrieve the affinity mask is creative at best. Just
because C does not allow encapsulation does not mean that the kernel has no
limits.

Retrieve a pointer to the affinity mask itself and use that. It's still
using an interface which is usually not for random drivers, but definitely
less hideous than the previous hack.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20201210194044.580936243@linutronix.de

Going through a full irq descriptor lookup instead of just using the proper
helper function which provides direct access is suboptimal.

In fact it _is_ wrong because the chip callback needs to get the chip data
which is relevant for the chip while using the irq descriptor variant
returns the irq chip data of the top level chip of a hierarchy. It does not
matter in this case because the chip is the top level chip, but that
doesn't make it more correct.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20201210194044.473308721@linutronix.de

Going through a full irq descriptor lookup instead of just using the proper
helper function which provides direct access is suboptimal.

In fact it _is_ wrong because the chip callback needs to get the chip data
which is relevant for the chip while using the irq descriptor variant
returns the irq chip data of the top level chip of a hierarchy. It does not
matter in this case because the chip is the top level chip, but that
doesn't make it more correct.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20201210194044.364211860@linutronix.de

Use the proper core function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/20201210194044.255887860@linutronix.de

First of all drivers have absolutely no business to dig into the internals
of an irq descriptor. That's core code and subject to change. All of this
information is readily available to /proc/interrupts in a safe and race
free way.

Remove the inspection code which is a blatant violation of subsystem
boundaries and racy against concurrent modifications of the interrupt
descriptor.

Print the irq line instead so the information can be looked up in a sane
way in /proc/interrupts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201210194044.157283633@linutronix.de

Let the core code do the fiddling with irq_desc.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201210194044.065003856@linutronix.de

Driver code has no business with the internals of the irq descriptor.

Aside of that the count is per interrupt line and therefore takes
interrupts from other devices into account which share the interrupt line
and are not handled by the graphics driver.

Replace it with a pmu private count which only counts interrupts which
originate from the graphics card.

To avoid atomics or heuristics of some sort make the counter field
'unsigned long'. That limits the count to 4e9 on 32bit which is a lot and
postprocessing can easily deal with the occasional wraparound.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: https://lore.kernel.org/r/20201210194043.957046529@linutronix.de

Nothing uses the result and nothing should ever use it in driver code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://lore.kernel.org/r/20201210194043.862572239@linutronix.de

The irq descriptor is already there, no need to look it up again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/20201210194043.769108348@linutronix.de

The irq descriptor is already there, no need to look it up again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-parisc@vger.kernel.org
Link: https://lore.kernel.org/r/20201210194043.659522455@linutronix.de

The irq descriptor is already there, no need to look it up again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201210194043.546326568@linutronix.de

The irq descriptor is already there, no need to look it up again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201210194043.454288890@linutronix.de

Most users of kstat_irqs_cpu() have the irq descriptor already. No point in
calling into the core code and looking it up once more.

Use it in per_cpu_count_show() to start with.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.362094758@linutronix.de

No more users outside the core code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.268774449@linutronix.de

The SMP variant works perfectly fine on UP as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-parisc@vger.kernel.org
Link: https://lore.kernel.org/r/20201210194043.172893840@linutronix.de

Both the per cpu stats and the accumulated count are accessed lockless and
can be concurrently modified. That's intentional and the stats are a rough
estimate anyway. Annotate them with data_race().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.067097663@linutronix.de

Provide an accessor to the effective interrupt affinity mask. Going to be
used to replace open coded fiddling with the irq descriptor.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.967177918@linutronix.de

irq_set_lockdep_class() is used from modules and requires irq_to_desc() to
be exported. Move it into the core code which lifts another requirement for
the export.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.860029489@linutronix.de

These checks are used by modules and prevent the removal of the export of
irq_to_desc(). Move the accessor into the core.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.703779349@linutronix.de

This function uses irq_to_desc() and is going to be used by modules to
replace the open coded irq_to_desc() (ab)usage. The final goal is to remove
the export of irq_to_desc() so driver cannot fiddle with it anymore.

Move it into the core code and fixup the usage sites to include the proper
header.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194042.548936472@linutronix.de

Merge tag 'irqchip-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates for 5.11 from Marc Zyngier:

  - Preliminary support for managed interrupts on platform devices
  - Correctly identify allocation of MSIs proxyied by another device
  - Remove the fasteoi IPI flow which has been proved useless
  - Generalise the Ocelot support to new SoCs
  - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation
  - Work around spurious interrupts on Qualcomm PDC
  - Random fixes and cleanups

Link: https://lore.kernel.org/r/20201212135626.1479884-1-maz@kernel.org

We have a problem if we use gpio-keys and configure wakeups such that
we only want one edge to wake us up.  AKA:
  wakeup-event-action = <EV_ACT_DEASSERTED>;
  wakeup-source;

Specifically we end up with a phantom interrupt that blocks suspend if
the line was already high and we want wakeups on rising edges (AKA we
want the GPIO to go low and then high again before we wake up).  The
opposite is also problematic.

Specifically, here's what's happening today:
1. Normally, gpio-keys configures to look for both edges.  Due to the
   current workaround introduced in commit c3c0c2e1 ("pinctrl:
   qcom: Handle broken/missing PDC dual edge IRQs on sc7180"), if the
   line was high we'd configure for falling edges.
2. At suspend time, we change to look for rising edges.
3. After qcom_pdc_gic_set_type() runs, we get a phantom interrupt.

We can solve this by just clearing the phantom interrupt.

NOTE: it is possible that this could cause problems for a client with
very specific needs, but there's not much we can do with this
hardware.  As an example, let's say the interrupt signal is currently
high and the client is looking for falling edges.  The client now
changes to look for rising edges.  The client could possibly expect
that if the line has a short pulse low (and back high) that it would
always be detected.  Specifically no matter when the pulse happened,
it should either have tripped the (old) falling edge trigger or the
(new) rising edge trigger.  We will simply not trip it.  We could
narrow down the race a bit by polling our parent before changing
types, but no matter what we do there will still be a period of time
where we can't tell the difference between a real transition (or more
than one transition) and the phantom.

Fixes: f55c73ae ("irqchip/pdc: Add PDC interrupt controller for QCOM SoCs")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Maulik Shah <mkshah@codeaurora.org>
Reviewed-by: Maulik Shah <mkshah@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20201211141514.v4.1.I2702919afc253e2a451bebc3b701b462b2d22344@changeid

Drivers for multi-queue platform devices may also want managed interrupts
for handling HW queue completion interrupts, so add support.

The function accepts an affinity descriptor pointer, which covers all IRQs
expected for the device.

The function is devm class as the only current in-tree user will also use
devm method for requesting the interrupts; as such, the function is made
as devm as it can ensure ordering of freeing the irq and disposing of the
mapping.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1606905417-183214-5-git-send-email-john.garry@huawei.com

The functionality of acpi_dev_irqresource_disabled() is same as in common
irqresource_disabled(), so drop acpi_dev_irqresource_disabled() in favour
of that function.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/1606905417-183214-4-git-send-email-john.garry@huawei.com

Add a common function to set the fields for a irq resource to disabled,
which mimics what is done in acpi_dev_irqresource_disabled(), with a view
to replace that function.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/1606905417-183214-3-git-send-email-john.garry@huawei.com

Add a function to allow the affinity of an interrupt be switched to
managed, such that interrupts allocated for platform devices may be
managed.

This new interface has certain limitations, and attempts to use it in the
following circumstances will fail:
- For when the kernel is configured for generic IRQ reservation mode (in
  config GENERIC_IRQ_RESERVATION_MODE). The reason being that it could
  conflict with managed vs. non-managed interrupt accounting.
- The interrupt is already started, which should not be the case during
  init
- The interrupt is already configured as managed, which means double init
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1606905417-183214-2-git-send-email-john.garry@huawei.com

An aliasing PCI bridge is another case where we should flag the
corresponding allocation as "proxied", as MSIs are coming with
the bridge's RID, and not the originating device's.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20201129135208.680293-4-maz@kernel.org

The ITS already has some notion of "shared" devices. Let's map the
MSI_ALLOC_FLAGS_PROXY_DEVICE flag onto this internal property.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20201129135208.680293-3-maz@kernel.org

We have two flavours of platform-MSI:

- MSIs generated by devices for themselves (the usual case)

- MSIs generated on behalf of other devices, as the generating
  device is some form of bridge (either a wire-to-MSI bridge,
  or even a non-transparent PCI bridge that repaints the PCI
  requester ID).

In the latter case, the underlying interrupt architecture may need
to track this in order to keep the mapping alive even when no MSI
are currently being generated.

Add a set of flags to the generic msi_alloc_info_t structure, as
well as the MSI_ALLOC_FLAGS_PROXY_DEVICE flag that will get
advertized by the platform-MSI code when allocating an irqdomain
for a device.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20201129135208.680293-2-maz@kernel.org

ti_sci_intr_irq_domain_free() assumes that out_irq of intr is stored in
data->chip_data and uses it for calling ti_sci irq_free() and then
mark the out_irq as available resource. But ti_sci_intr_irq_domain_alloc()
is storing p_hwirq(parent's hardware irq) which is translated from out_irq.
This is causing resource leakage and eventually out_irq resources might
be exhausted. Fix ti_sci_intr_irq_domain_alloc() by storing the out_irq
in data->chip_data.

Fixes: a5b659bd ("irqchip/ti-sci-intr: Add support for INTR being a parent to INTR")
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201102120631.11165-1-lokeshvutla@ti.com

On a successful probe, the driver tries to print a success message with
INTA device id. It uses pdev->id for printing the id but id is stored in
inta->ti_sci_id. Fix it by correcting the dev_info parameter.

Fixes: 5c4b585d ("irqchip/ti-sci-inta: Add support for INTA directly connecting to GIC")
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201102120614.11109-1-lokeshvutla@ti.com

NPS platform has been removed from ARC port and there are no in-tree
users of it now. So RIP !
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <maz@kernel.org>
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20201105212210.1891598-3-vgupta@synopsys.com