Unlike most drіvers that simply pass the maximum possible vectors to
pci_alloc_irq_vectors NVMe needs to configure the device before allocting
the vectors, so it needs a manual update for the new scheme of using
all present CPUs.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: linux-block@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Link: http://lkml.kernel.org/r/20170626102058.10200-4-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Currently we only create hctx for online CPUs, which can lead to a lot
of churn due to frequent soft offline / online operations.  Instead
allocate one for each present CPU to avoid this and dramatically simplify
the code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: linux-block@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Link: http://lkml.kernel.org/r/20170626102058.10200-3-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This way we get a nice distribution independent of the current cpu
online / offline state.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: linux-block@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Link: http://lkml.kernel.org/r/20170626102058.10200-2-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Check irq state in enable/disable/unmask/mask_irq to avoid unnecessary
low level irq function calls.

This has two advantages:
    - Conditionals are faster than hardware access

    - Solves issues with the underlying refcounting of the pinctrl
      infrastructure
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: tfiga@chromium.org
Cc: briannorris@chromium.org
Cc: dianders@chromium.org
Link: http://lkml.kernel.org/r/1498476814-12563-2-git-send-email-jeffy.chen@rock-chips.com

The irq default state is set to disabled when allocating irq desc, but the
masked state flag is not set. This is inconsistent vs. the state tracking
logic which is used to prevent unnecessary calls to hardware level irq chip
functions.

Set the masked state flag as well.
Signed-off-by: NJeffy Chen <jeffy.chen@rock-chips.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: tfiga@chromium.org
Cc: briannorris@chromium.org
Cc: dianders@chromium.org
Link: http://lkml.kernel.org/r/1498476814-12563-1-git-send-email-jeffy.chen@rock-chips.com

An interrupt behaves with a burst of activity with periodic interval of time
followed by one or two peaks of longer interval.

As the time intervals are periodic, statistically speaking they follow a normal
distribution and each interrupts can be tracked individually.

Add a mechanism to compute the statistics on all interrupts, except the
timers which are deterministic from a prediction point of view, as their
expiry time is known.

The goal is to extract the periodicity for each interrupt, with the last
timestamp and sum them, so the next event can be predicted to a certain
extent.

Taking the earliest prediction gives the expected wakeup on the system
(assuming a timer won't expire before).
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-2-git-send-email-daniel.lezcano@linaro.org

The interrupt framework gives a lot of information about each interrupt. It
does not keep track of when those interrupts occur though, which is a
prerequisite for estimating the next interrupt arrival for power management
purposes.

Add a mechanism to record the timestamp for each interrupt occurrences in a
per-CPU circular buffer to help with the prediction of the next occurrence
using a statistical model.

Each CPU can store up to IRQ_TIMINGS_SIZE events <irq, timestamp>, the
current value of IRQ_TIMINGS_SIZE is 32.

Each event is encoded into a single u64, where the high 48 bits are used
for the timestamp and the low 16 bits are for the irq number.

A static key is introduced so when the irq prediction is switched off at
runtime, the overhead is near to zero.

It results in most of the code in internals.h for inline reasons and a very
few in the new file timings.c. The latter will contain more in the next patch
which will provide the statistical model for the next event prediction.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org

debugfs_remove() has it's own NULL pointer check. Remove the conditional
and make irq_remove_debugfs_entry() an inline helper
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Merge tag 'irqchip-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates for v4.13 from Marc Zyngier

- support for the new Marvell wire-to-MSI bridge
- support for the Aspeed I2C irqchip
- Armada XP370 per-cpu interrupt fixes
- GICv3 ITS ACPI NUMA support
- sunxi-nmi cleanup and updates for new platform support
- various GICv3 ITS cleanups and fixes
- some constifying in various places

The current ITS driver is assuming every ITS hardware implementation
supports minimum of 16bit INTID. But this is not true, as per GICv3
specification, INTID field is IMPLEMENTATION DEFINED in the range of
14-24 bits. We might see an unpredictable system behavior on systems
where hardware support less than 16bits and software tries to use
64K LPI interrupts.

On Qualcomm Datacenter Technologies QDF2400 platform, boot log shows
confusing information about number of LPI chunks as shown below. The
QDF2400 ITS hardware supports 24bit INTID.

This patch allocates the memory resources for PEND/PROP tables based
on discoverable value which is specified in GITS_TYPER.IDbits. Also
it fixes the log message that reflects the correct number of LPI
chunks were allocated.

ITS@0xff7efe0000: allocated 524288 Devices @3c0400000 (indirect, esz 8, psz 64K, shr 1)
ITS@0xff7efe0000: allocated 8192 Interrupt Collections @3c0130000 (flat, esz 8, psz 64K, shr 1)
ITS@0xff7efe0000: allocated 8192 Virtual CPUs @3c0140000 (flat, esz 8, psz 64K, shr 1)
ITS: Allocated 524032 chunks for LPIs
PCI/MSI: ITS@0xff7efe0000 domain created
Platform MSI: ITS@0xff7efe0000 domain created
Signed-off-by: NShanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Add code to parse SRAT ITS Affinity sub table as defined in ACPI 6.2.
Later in per device probe, ITS devices are mapped to numa node using
ITS Id to proximity domain mapping.

[maz: fix dependency on ACPICA, fixed structure name, minor cleanups]
Reviewed-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NGanapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

of_device_ids are not supposed to change at runtime. All functions
working with of_device_ids provided by <linux/of.h> work with const
of_device_ids. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

of_device_ids are not supposed to change at runtime. All functions
working with of_device_ids provided by <linux/of.h> work with const
of_device_ids. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The Marvell ICU unit is found in the CP110 block of the Marvell Armada
7K and 8K SoCs. It collects the wired interrupts of the devices located
in the CP110 and turns them into SPI interrupts in the GIC located in
the AP806 side of the SoC, by using a memory transaction.

Until now, the ICU was configured in a static fashion by the firmware,
and Linux was relying on this static configuration. By having Linux
configure the ICU, we are more flexible, and we can allocate dynamically
the GIC SPI interrupts only for devices that are actually in use.

The driver was initially written by Hanna Hawa <hannah@marvell.com>.
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

This commit adds a simple driver for the Marvell GICP, a hardware unit
that converts memory writes into GIC SPI interrupts. The driver provides
a number of functions to the ICU driver to allocate GICP interrupts, and
get the physical addresses that the ICUs should write to to set/clear
interrupts.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

This commit adds the Device Tree binding documentation for the Marvell
ICU interrupt controller, which collects wired interrupts from the
devices located into the CP110 hardware block of Marvell Armada 7K/8K,
and converts them into SPI interrupts in the GIC located in the AP
hardware block, using the GICP extension.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

It did seem like a good idea at the time, but it never really
caught on, and auto-recursive domains remain unused 3 years after
having been introduced.

Oh well, time for a late spring cleanup.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that we have irq_domain_update_bus_token(), switch everyone over
to it. The debugfs code thanks you for your continued support.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We can have irq domains that are identified by the same fwnode
(because they are serviced by the same HW), and yet have different
functionnality (because they serve different busses, for example).
This is what we use the bus_token field.

Since we don't use this field when generating the domain name,
all the aliasing domains will get the same name, and the debugfs
file creation fails. Also, bus_token is updated by individual drivers,
and the core code is unaware of that update.

In order to sort this mess, let's introduce a helper that takes care
of updating bus_token, and regenerate the debugfs file.

A separate patch will update all the individual users.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Currently the irq vector spread algorithm is restricted to online CPUs,
which ties the IRQ mapping to the currently online devices and doesn't deal
nicely with the fact that CPUs could come and go rapidly due to e.g. power
management.

Instead assign vectors to all present CPUs to avoid this churn.

Build a map of all possible CPUs for a given node, as the architectures
only provide a map of all onlines CPUs. Do this dynamically on each call
for the vector assingments, which is a bit suboptimal and could be
optimized in the future by provinding a mapping from the arch code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-nvme@lists.infradead.org
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170603140403.27379-5-hch@lst.de

If the interrupt destination mode of the APIC is physical then the
effective affinity is restricted to a single CPU.

Mark the interrupt accordingly in the domain allocation code, so the core
code can avoid pointless affinity setting attempts.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.508846202@linutronix.de

Avoid trying to add a newly online CPU to the effective affinity mask of an
started up interrupt. That interrupt will either stay on the already online
CPU or move around for no value.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.431321047@linutronix.de

Many interrupt chips allow only a single CPU as interrupt target. The core
code has no knowledge about that. That's unfortunate as it could avoid
trying to readd a newly online CPU to the effective affinity mask.

Add the status flag and the necessary accessors.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.352343969@linutronix.de

If a CPU goes offline, interrupts affine to the CPU are moved away. If the
outgoing CPU is the last CPU in the affinity mask the migration code breaks
the affinity and sets it it all online cpus.

This is a problem for affinity managed interrupts as CPU hotplug is often
used for power management purposes. If the affinity is broken, the
interrupt is not longer affine to the CPUs to which it was allocated.

The affinity spreading allows to lay out multi queue devices in a way that
they are assigned to a single CPU or a group of CPUs. If the last CPU goes
offline, then the queue is not longer used, so the interrupt can be
shutdown gracefully and parked until one of the assigned CPUs comes online
again.

Add a graceful shutdown mechanism into the irq affinity breaking code path,
mark the irq as MANAGED_SHUTDOWN and leave the affinity mask unmodified.

In the online path, scan the active interrupts for managed interrupts and
if the interrupt is functional and the newly online CPU is part of the
affinity mask, restart the interrupt if it is marked MANAGED_SHUTDOWN or if
the interrupts is started up, try to add the CPU back to the effective
affinity mask.
Originally-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170619235447.273417334@linutronix.de

Affinity managed interrupts should keep their assigned affinity accross CPU
hotplug. To avoid magic hackery in device drivers, the core code shall
manage them transparently and set these interrupts into a managed shutdown
state when the last CPU of the assigned affinity mask goes offline. The
interrupt will be restarted when one of the CPUs in the assigned affinity
mask comes back online.

Add the necessary logic to irq_startup(). If an interrupt is requested and
started up, the code checks whether it is affinity managed and if so, it
checks whether a CPU in the interrupts affinity mask is online. If not, it
puts the interrupt into managed shutdown state. 
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.189851170@linutronix.de

In order to handle managed interrupts gracefully on irq_startup() so they
won't lose their assigned affinity, it's necessary to allow startups which
keep the interrupts in managed shutdown state, if none of the assigend CPUs
is online. This allows drivers to request interrupts w/o the CPUs being
online, which avoid online/offline churn in drivers.

Add a force argument which can override that decision and let only
request_irq() and enable_irq() allow the managed shutdown
handling. enable_irq() is required, because the interrupt might be
requested with IRQF_NOAUTOEN and enable_irq() invokes irq_startup() which
would then wreckage the assignment again. All other callers force startup
and potentially break the assigned affinity.

No functional change as this only adds the function argument.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.112094565@linutronix.de

Split out the inner workings of irq_startup() so it can be reused to handle
managed interrupts gracefully.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235447.033235144@linutronix.de

Affinity managed interrupts should keep their assigned affinity accross CPU
hotplug. To avoid magic hackery in device drivers, the core code shall
manage them transparently. This will set these interrupts into a managed
shutdown state when the last CPU of the assigned affinity mask goes
offline. The interrupt will be restarted when one of the CPUs in the
assigned affinity mask comes back online.

Introduce the necessary state flag and the accessor functions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.954523476@linutronix.de

Add the effective irq mask update to the apic implementations and enable
effective irq masks for x86.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.878370703@linutronix.de

Update the effective affinity mask when an interrupt was successfully
targeted to a CPU.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.799944725@linutronix.de

The decision to which CPUs an interrupt is effectively routed happens in
the various apic->cpu_mask_to_apicid() implementations

To support effective affinity masks this information needs to be updated in
irq_data. Add a pointer to irq_data to the callbacks and feed it through
the call chain.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.720739075@linutronix.de

All implementations of apic->cpu_mask_to_apicid_and() and the two incoming
cpumasks to search for the target.

Move that operation to the call site and rename it to cpu_mask_to_apicid()
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.641575516@linutronix.de

All implementations of apic->cpu_mask_to_apicid_and() mask out the offline
cpus. The callsite already has a mask available, which has the offline CPUs
removed. Use that and remove the extra bits.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.560868224@linutronix.de

Same functionality except the extra bits ored on the apicid.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.482841015@linutronix.de

No point in having inlines assigned to function pointers at multiple
places. Just bloats the text.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.405975721@linutronix.de

If the architecture supports the effective affinity mask, migrating
interrupts away which are not targeted by the effective mask is
pointless.

They can stay in the user or system supplied affinity mask, but won't be
targetted at any given point as the affinity setter functions need to
validate against the online cpu mask anyway.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.328488490@linutronix.de

There is currently no way to evaluate the effective affinity mask of a
given interrupt. Many irq chips allow only a single target CPU or a subset
of CPUs in the affinity mask.

Updating the mask at the time of setting the affinity to the subset would
be counterproductive because information for cpu hotplug about assigned
interrupt affinities gets lost. On CPU hotplug it's also pointless to force
migrate an interrupt, which is not targeted at the CPU effectively. But
currently the information is not available.

Provide a seperate mask to be updated by the irq_chip->irq_set_affinity()
implementations. Implement the read only proc files so the user can see the
effective mask as well w/o trying to deduce it from /proc/interrupts.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.247834245@linutronix.de

The proc file setup repeats the same ugly type cast for the irq number over
and over. Do it once and hand in the local void pointer.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.160866358@linutronix.de

All callers hand in GPF_KERNEL. No point to have an extra argument for
that.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.082544752@linutronix.de

The third argument of the internal helper function is unused. Remove it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.004958600@linutronix.de