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2017-11-15Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "The big highlight is support for the Scalable Vector Extension (SVE) which required extensive ABI work to ensure we don't break existing applications by blowing away their signal stack with the rather large new vector context (<= 2 kbit per vector register). There's further work to be done optimising things like exception return, but the ABI is solid now. Much of the line count comes from some new PMU drivers we have, but they're pretty self-contained and I suspect we'll have more of them in future. Plenty of acronym soup here: - initial support for the Scalable Vector Extension (SVE) - improved handling for SError interrupts (required to handle RAS events) - enable GCC support for 128-bit integer types - remove kernel text addresses from backtraces and register dumps - use of WFE to implement long delay()s - ACPI IORT updates from Lorenzo Pieralisi - perf PMU driver for the Statistical Profiling Extension (SPE) - perf PMU driver for Hisilicon's system PMUs - misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits) arm64: Make ARMV8_DEPRECATED depend on SYSCTL arm64: Implement __lshrti3 library function arm64: support __int128 on gcc 5+ arm64/sve: Add documentation arm64/sve: Detect SVE and activate runtime support arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Prevent guests from using SVE arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: Add prctl controls for userspace vector length management arm64/sve: ptrace and ELF coredump support arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Probe SVE capabilities and usable vector lengths arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Backend logic for setting the vector length arm64/sve: Signal handling support arm64/sve: Support vector length resetting for new processes arm64/sve: Core task context handling arm64/sve: Low-level CPU setup ...
2017-11-01irq/core: Fix boot crash when the irqaffinity= boot parameter is passed on ↵Rakib Mullick
CPUMASK_OFFSTACK=y kernels(v1) When the irqaffinity= kernel parameter is passed in a CPUMASK_OFFSTACK=y kernel, it fails to boot, because zalloc_cpumask_var() cannot be used before initializing the slab allocator to allocate a cpumask. So, use alloc_bootmem_cpumask_var() instead. Also do some cleanups while at it: in init_irq_default_affinity() remove an #ifdef via using cpumask_available(). Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20171026045800.27087-1-rakib.mullick@gmail.com Link: http://lkml.kernel.org/r/20171101041451.12581-1-rakib.mullick@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-18genirq: export irq_get_percpu_devid_partition to modulesWill Deacon
Any modular driver using cluster-affine PPIs needs to be able to call irq_get_percpu_devid_partition so that it can enable the IRQ on the correct subset of CPUs. This patch exports the symbol so that it can be called from within a module. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-09-25genirq: Set managed shut down flag at initThomas Gleixner
Managed interrupts should start up in managed shutdown mode. Set the status flag when initialising the irq descriptor. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Yu Chen <yu.c.chen@intel.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rui Zhang <rui.zhang@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Len Brown <lenb@kernel.org> Link: https://lkml.kernel.org/r/20170913213152.669687742@linutronix.de
2017-09-25genirq/debugfs: Show debug information for all irq descriptorsThomas Gleixner
Currently the debugfs shows only information about actively used interrupts like /proc/irq/ does. That's fine for most cases, but not helpful when internals of allocated, but unused interrupt descriptors have to debugged. It's also useful to provide information about all descriptors so leaks can be debugged in a simpler way. Move the debugfs registration to the descriptor allocation code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Juergen Gross <jgross@suse.com> Tested-by: Yu Chen <yu.c.chen@intel.com> Acked-by: Juergen Gross <jgross@suse.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rui Zhang <rui.zhang@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Len Brown <lenb@kernel.org> Link: https://lkml.kernel.org/r/20170913213152.355525908@linutronix.de
2017-09-07genirq: Make sparse_irq_lock protect what it should protectThomas Gleixner
for_each_active_irq() iterates the sparse irq allocation bitmap. The caller must hold sparse_irq_lock. Several code pathes expect that an active bit in the sparse bitmap also has a valid interrupt descriptor. Unfortunately that's not true. The (de)allocation is a two step process, which holds the sparse_irq_lock only across the queue/remove from the radix tree and the set/clear in the allocation bitmap. If a iteration locks sparse_irq_lock between the two steps, then it might see an active bit but the corresponding irq descriptor is NULL. If that is dereferenced unconditionally, then the kernel oopses. Of course, all iterator sites could be audited and fixed, but.... There is no reason why the sparse_irq_lock needs to be dropped between the two steps, in fact the code becomes simpler when the mutex is held across both and the semantics become more straight forward, so future problems of missing NULL pointer checks in the iteration are avoided and all existing sites are fixed in one go. Expand the lock held sections so both operations are covered and the bitmap and the radixtree are in sync. Fixes: a05a900a51c7 ("genirq: Make sparse_lock a mutex") Reported-and-tested-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2017-07-09Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: - A few fixes mopping up the fallout of the big irq overhaul - Move the interrupt resource management logic out of the spin locked, irq disabled region to avoid unnecessary restrictions of the resource callbacks - Preparation for reworking the per cpu irq request function. * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqdomain: Allow ACPI device nodes to be used as irqdomain identifiers genirq/debugfs: Remove redundant NULL pointer check genirq: Allow to pass the IRQF_TIMER flag with percpu irq request genirq/timings: Move free timings out of spinlocked region genirq: Move irq resource handling out of spinlocked region genirq: Add mutex to irq desc to serialize request/free_irq() genirq: Move bus locking into __setup_irq() genirq: Force inlining of __irq_startup_managed to prevent build failure genirq/debugfs: Fix build for !CONFIG_IRQ_DOMAIN
2017-07-04genirq: Add mutex to irq desc to serialize request/free_irq()Thomas Gleixner
The irq_request/release_resources() callbacks ar currently invoked under desc->lock with interrupts disabled. This is a source of problems on RT and conceptually not required. Add a seperate mutex to struct irq_desc which allows to serialize request/free_irq(), which can be used to move the resource functions out of the desc->lock held region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Heiko Stuebner <heiko@sntech.de> Cc: Julia Cartwright <julia@ni.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Brian Norris <briannorris@chromium.org> Cc: Doug Anderson <dianders@chromium.org> Cc: linux-rockchip@lists.infradead.org Cc: John Keeping <john@metanate.com> Cc: linux-gpio@vger.kernel.org Link: http://lkml.kernel.org/r/20170629214344.039220922@linutronix.de
2017-07-03Merge tag 'docs-4.13' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "There has been a fair amount of activity in the docs tree this time around. Highlights include: - Conversion of a bunch of security documentation into RST - The conversion of the remaining DocBook templates by The Amazing Mauro Machine. We can now drop the entire DocBook build chain. - The usual collection of fixes and minor updates" * tag 'docs-4.13' of git://git.lwn.net/linux: (90 commits) scripts/kernel-doc: handle DECLARE_HASHTABLE Documentation: atomic_ops.txt is core-api/atomic_ops.rst Docs: clean up some DocBook loose ends Make the main documentation title less Geocities Docs: Use kernel-figure in vidioc-g-selection.rst Docs: fix table problems in ras.rst Docs: Fix breakage with Sphinx 1.5 and upper Docs: Include the Latex "ifthen" package doc/kokr/howto: Only send regression fixes after -rc1 docs-rst: fix broken links to dynamic-debug-howto in kernel-parameters doc: Document suitability of IBM Verse for kernel development Doc: fix a markup error in coding-style.rst docs: driver-api: i2c: remove some outdated information Documentation: DMA API: fix a typo in a function name Docs: Insert missing space to separate link from text doc/ko_KR/memory-barriers: Update control-dependencies example Documentation, kbuild: fix typo "minimun" -> "minimum" docs: Fix some formatting issues in request-key.rst doc: ReSTify keys-trusted-encrypted.txt doc: ReSTify keys-request-key.txt ...
2017-06-26genirq: Set irq masked state when initializing irq_descJeffy Chen
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: Jeffy Chen <jeffy.chen@rock-chips.com> Signed-off-by: Thomas 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
2017-06-22genirq: Introduce effective affinity maskThomas Gleixner
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: Thomas 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
2017-06-22genirq: Remove pointless gfp argumentThomas Gleixner
All callers hand in GPF_KERNEL. No point to have an extra argument for that. Signed-off-by: Thomas 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
2017-06-22genirq/debugfs: Add proper debugfs interfaceThomas Gleixner
Debugging (hierarchical) interupt domains is tedious as there is no information about the hierarchy and no information about states of interrupts in the various domain levels. Add a debugfs directory 'irq' and subdirectories 'domains' and 'irqs'. The domains directory contains the domain files. The content is information about the domain. If the domain is part of a hierarchy then the parent domains are printed as well. # ls /sys/kernel/debug/irq/domains/ default INTEL-IR-2 INTEL-IR-MSI-2 IO-APIC-IR-2 PCI-MSI DMAR-MSI INTEL-IR-3 INTEL-IR-MSI-3 IO-APIC-IR-3 unknown-1 INTEL-IR-0 INTEL-IR-MSI-0 IO-APIC-IR-0 IO-APIC-IR-4 VECTOR INTEL-IR-1 INTEL-IR-MSI-1 IO-APIC-IR-1 PCI-HT # cat /sys/kernel/debug/irq/domains/VECTOR name: VECTOR size: 0 mapped: 216 flags: 0x00000041 # cat /sys/kernel/debug/irq/domains/IO-APIC-IR-0 name: IO-APIC-IR-0 size: 24 mapped: 19 flags: 0x00000041 parent: INTEL-IR-3 name: INTEL-IR-3 size: 65536 mapped: 167 flags: 0x00000041 parent: VECTOR name: VECTOR size: 0 mapped: 216 flags: 0x00000041 Unfortunately there is no per cpu information about the VECTOR domain (yet). The irqs directory contains detailed information about mapped interrupts. # cat /sys/kernel/debug/irq/irqs/3 handler: handle_edge_irq status: 0x00004000 istate: 0x00000000 ddepth: 1 wdepth: 0 dstate: 0x01018000 IRQD_IRQ_DISABLED IRQD_SINGLE_TARGET IRQD_MOVE_PCNTXT node: 0 affinity: 0-143 effectiv: 0 pending: domain: IO-APIC-IR-0 hwirq: 0x3 chip: IR-IO-APIC flags: 0x10 IRQCHIP_SKIP_SET_WAKE parent: domain: INTEL-IR-3 hwirq: 0x20000 chip: INTEL-IR flags: 0x0 parent: domain: VECTOR hwirq: 0x3 chip: APIC flags: 0x0 This was developed to simplify the debugging of the managed affinity changes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Jens Axboe <axboe@kernel.dk> 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/20170619235444.537566163@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-26genirq: Make early_irq_init() print out more informativeVincent Legoll
The printk in early_irq_init() is cryptic and badly formatted: NR_IRQS:33024 nr_irqs:968 16 The last number is the number of preallocated interrupts, so add a prefix to it: NR_IRQS: 33024, nr_irqs: 968, preallocated irqs: 16 Cleanup the formatting for better readability as well. Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1494318849-6733-1-git-send-email-vincent.legoll@gmail.com
2017-05-16irq: update genericirq book locationMauro Carvalho Chehab
This book got converted from DocBook. Update its references to point to the current location. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-15Merge branch 'irq/for-block' into irq/coreThomas Gleixner
Add the new irq spreading infrastructure.
2016-09-14genirq/msi: Switch to new irq spreading infrastructureThomas Gleixner
Switch MSI over to the new spreading code. If a pci device contains a valid pointer to a cpumask, then this mask is used for spreading otherwise the online cpu mask is used. This allows a driver to restrict the spread to a subset of CPUs, e.g. cpus on a particular node. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: axboe@fb.com Cc: keith.busch@intel.com Cc: agordeev@redhat.com Cc: linux-block@vger.kernel.org Link: http://lkml.kernel.org/r/1473862739-15032-4-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-14genirq: Expose interrupt information through sysfsCraig Gallek
Information about interrupts is exposed via /proc/interrupts, but the format of that file has changed over kernel versions and differs across architectures. It also has varying column numbers depending on hardware. That all makes it hard for tools to parse. To solve this, expose the information through sysfs so each irq attribute is in a separate file in a consistent, machine parsable way. This feature is only available when both CONFIG_SPARSE_IRQ and CONFIG_SYSFS are enabled. Examples: /sys/kernel/irq/18/actions: i801_smbus,ehci_hcd:usb1,uhci_hcd:usb7 /sys/kernel/irq/18/chip_name: IR-IO-APIC /sys/kernel/irq/18/hwirq: 18 /sys/kernel/irq/18/name: fasteoi /sys/kernel/irq/18/per_cpu_count: 0,0 /sys/kernel/irq/18/type: level /sys/kernel/irq/25/actions: ahci0 /sys/kernel/irq/25/chip_name: IR-PCI-MSI /sys/kernel/irq/25/hwirq: 512000 /sys/kernel/irq/25/name: edge /sys/kernel/irq/25/per_cpu_count: 29036,0 /sys/kernel/irq/25/type: edge [ tglx: Moved kobject_del() under sparse_irq_lock, massaged code comments and changelog ] Signed-off-by: Craig Gallek <kraig@google.com> Cc: David Decotigny <decot@google.com> Link: http://lkml.kernel.org/r/1473783291-122873-1-git-send-email-kraigatgoog@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-07-04genirq: Use affinity hint in irqdesc allocationThomas Gleixner
Use the affinity hint in the irqdesc allocator. The hint is used to determine the node for the allocation and to set the affinity of the interrupt. If multiple interrupts are allocated (multi-MSI) then the allocator iterates over the cpumask and for each set cpu it allocates on their node and sets the initial affinity to that cpu. If a single interrupt is allocated (MSI-X) then the allocator uses the first cpu in the mask to compute the allocation node and uses the mask for the initial affinity setting. Interrupts set up this way are marked with the AFFINITY_MANAGED flag to prevent userspace from messing with their affinity settings. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: linux-nvme@lists.infradead.org Cc: axboe@fb.com Cc: agordeev@redhat.com Link: http://lkml.kernel.org/r/1467621574-8277-5-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-07-04genirq: Add affinity hint to irq allocationThomas Gleixner
Add an extra argument to the irq(domain) allocation functions, so we can hand down affinity hints to the allocator. Thats necessary to implement proper support for multiqueue devices. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: linux-nvme@lists.infradead.org Cc: axboe@fb.com Cc: agordeev@redhat.com Link: http://lkml.kernel.org/r/1467621574-8277-4-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-05-02genirq: Allow the affinity of a percpu interrupt to be set/retrievedMarc Zyngier
In order to prepare the genirq layer for the concept of partitionned percpu interrupts, let's allow an affinity to be associated with such an interrupt. We introduce: - irq_set_percpu_devid_partition: flag an interrupt as a percpu-devid interrupt, and associate it with an affinity - irq_get_percpu_devid_partition: allow the affinity of that interrupt to be retrieved. This will allow a driver to discover which CPUs the per-cpu interrupt can actually fire on. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: devicetree@vger.kernel.org Cc: Jason Cooper <jason@lakedaemon.net> Cc: Will Deacon <will.deacon@arm.com> Cc: Rob Herring <robh+dt@kernel.org> Link: http://lkml.kernel.org/r/1460365075-7316-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-02-08genirq: Add default affinity mask command line optionThomas Gleixner
If we isolate CPUs, then we don't want random device interrupts on them. Even w/o the user space irq balancer enabled we can end up with irqs on non boot cpus and chasing newly requested interrupts is a tedious task. Allow to restrict the default irq affinity mask. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1602031948190.25254@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-14genirq: Free irq_desc with rcuThomas Gleixner
The new VMD device driver needs to iterate over a list of "demultiplexing" interrupts. Protecting that list with a lock is not possible because the list is also required in code pathes which hold irq descriptor lock. Therefor the demultiplexing interrupt handler would create a lock inversion scenario if it calls a demux handler with the list protection lock held. A solution for this is to free the irq descriptor via RCU, so the list can be walked with rcu read lock held. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Keith Busch <keith.busch@intel.com>
2015-09-16genirq: Remove irq argument from irq flow handlersThomas Gleixner
Most interrupt flow handlers do not use the irq argument. Those few which use it can retrieve the irq number from the irq descriptor. Remove the argument. Search and replace was done with coccinelle and some extra helper scripts around it. Thanks to Julia for her help! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-09-16genirq: Move field 'msi_desc' from irq_data into irq_common_dataJiang Liu
MSI descriptors are per-irq instead of per irqchip, so move it into struct irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1433145945-789-35-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Move field 'affinity' from irq_data into irq_common_dataJiang Liu
Irq affinity mask is per-irq instead of per irqchip, so move it into struct irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1433303281-27688-1-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Move field 'handler_data' from irq_data into irq_common_dataJiang Liu
Handler data (handler_data) is per-irq instead of per irqchip, so move it into struct irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1433145945-789-13-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Move field 'node' from irq_data into irq_common_dataJiang Liu
NUMA node information is per-irq instead of per-irqchip, so move it into struct irq_common_data. Also use CONFIG_NUMA to guard irq_common_data.node. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1433145945-789-8-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-11genirq: Remove the parameter 'irq' of kstat_incr_irqs_this_cpu()Jiang Liu
The first parameter 'irq' is never used by kstat_incr_irqs_this_cpu(). Remove it. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1433391238-19471-16-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-20Merge branch 'irq/for-x86' into irq/coreThomas Gleixner
Get the infrastructure patches which are required for x86/apic into core
2015-06-12genirq: Introduce helper function irq_data_get_node()Jiang Liu
Introduce helper function irq_data_get_node() and variants thereof to hide struct irq_data implementation details. Convert the core code to use them. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1433145945-789-5-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-12genirq: Introduce struct irq_common_data to host shared irq dataJiang Liu
With the introduction of hierarchy irqdomain, struct irq_data becomes per-chip instead of per-irq and there may be multiple irq_datas associated with the same irq. Some per-irq data stored in struct irq_data now may get duplicated into multiple irq_datas, and causes inconsistent view. So introduce struct irq_common_data to host per-irq common data and to achieve consistent view among irq_chips. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1433145945-789-4-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05genirq: Fix type inconsistencyNicholas Mc Guire
The return type of kstat_irqs_usr() is unsigned int and kstat_irqs() also returns unsigned int so sum should be unsigned int here as well. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Link: http://lkml.kernel.org/r/1430642951-23964-1-git-send-email-hofrat@osadl.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-05-05genirq: Fix unnecessary automatic type conversionNicholas Mc Guire
kstat_irqs is unsigned int and the return type of kstat_irqs() is also unsigned int so sum should be unsigned int as well even if the result is correct due to automatic type conversion. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Link: http://lkml.kernel.org/r/1430642930-23929-1-git-send-email-hofrat@osadl.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-12-13genirq: Prevent proc race against freeing of irq descriptorsThomas Gleixner
Since the rework of the sparse interrupt code to actually free the unused interrupt descriptors there exists a race between the /proc interfaces to the irq subsystem and the code which frees the interrupt descriptor. CPU0 CPU1 show_interrupts() desc = irq_to_desc(X); free_desc(desc) remove_from_radix_tree(); kfree(desc); raw_spinlock_irq(&desc->lock); /proc/interrupts is the only interface which can actively corrupt kernel memory via the lock access. /proc/stat can only read from freed memory. Extremly hard to trigger, but possible. The interfaces in /proc/irq/N/ are not affected by this because the removal of the proc file is serialized in procfs against concurrent readers/writers. The removal happens before the descriptor is freed. For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue as the descriptor is never freed. It's merely cleared out with the irq descriptor lock held. So any concurrent proc access will either see the old correct value or the cleared out ones. Protect the lookup and access to the irq descriptor in show_interrupts() with the sparse_irq_lock. Provide kstat_irqs_usr() which is protecting the lookup and access with sparse_irq_lock and switch /proc/stat to use it. Document the existing kstat_irqs interfaces so it's clear that the caller needs to take care about protection. The users of these interfaces are either not affected due to SPARSE_IRQ=n or already protected against removal. Fixes: 1f5a5b87f78f "genirq: Implement a sane sparse_irq allocator" Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2014-09-03genirq: Add irq_domain-aware core IRQ handlerMarc Zyngier
Calling irq_find_mapping from outside a irq_{enter,exit} section is unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled: If coming from the idle state, the rcu_read_lock call in irq_find_mapping will generate an unpleasant warning: <quote> =============================== [ INFO: suspicious RCU usage. ] 3.16.0-rc1+ #135 Not tainted ------------------------------- include/linux/rcupdate.h:871 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 1 lock held by swapper/0/0: #0: (rcu_read_lock){......}, at: [<ffffffc00010206c>] irq_find_mapping+0x4c/0x198 </quote> As this issue is fairly widespread and involves at least three different architectures, a possible solution is to add a new handle_domain_irq entry point into the generic IRQ code that the interrupt controller code can call. This new function takes an irq_domain, and calls into irq_find_domain inside the irq_{enter,exit} block. An additional "lookup" parameter is used to allow non-domain architecture code to be replaced by this as well. Interrupt controllers can then be updated to use the new mechanism. This code is sitting behind a new CONFIG_HANDLE_DOMAIN_IRQ, as not all architectures implement set_irq_regs (yes, mn10300, I'm looking at you...). Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/1409047421-27649-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-07-05genirq: Fix memory leak when calling irq_free_hwirqs()Keith Busch
irq_free_hwirqs() always calls irq_free_descs() with a cnt == 0 which makes it a no-op since the interrupt count to free is decremented in itself. Fixes: 7b6ef1262549f6afc5c881aaef80beb8fd15f908 Signed-off-by: Keith Busch <keith.busch@intel.com> Acked-by: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/1404167084-8070-1-git-send-email-keith.busch@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-16genirq: Remove dynamic_irq messThomas Gleixner
No more users. Get rid of the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Grant Likely <grant.likely@linaro.org> Tested-by: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140507154341.012847637@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-16genirq: Replace dynamic_irq_init/cleanupThomas Gleixner
Create a new interface and confine it with a config switch which makes clear that this is just legacy support and not to be used for new code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Grant Likely <grant.likely@linaro.org> Tested-by: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140507154340.574437049@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-16genirq: Remove irq_reserve_irq[s]Thomas Gleixner
No more users. And it's not going to come back. If you need hotplugable irq chips, use irq domains. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-and-acked-by: Grant Likely <grant.likely@linaro.org> Tested-by: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140507154340.302183048@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-16genirq: Replace reserve_irqs in core codeThomas Gleixner
We want to get rid of the public interface. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Grant Likely <grant.likely@linaro.org> Tested-by: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140507154340.061990194@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-16genirq: Provide generic hwirq allocation facilityThomas Gleixner
Not really the solution to the problem, but at least it confines the mess in the core code and allows to get rid of the create/destroy_irq variants from hell, i.e. 3 implementations with different semantics plus the x86 specific variants __create_irqs and create_irq_nr which have been invented in another circle of hell. x86 : x86 should be converted to irq domains and I'm deliberately making it impossible to do the multi-vector MSI support by adding more crap to the current mess. It's not that hard to do and I'm really tired of the trainwrecks which have been invented by baindaid engineering so far. Any attempt to do multi-vector MSI or ioapic hotplug without converting to irq domains is NAKed hereby. tile: Might use irq domains as well, but it has a very limited interrupt space, so handling it via this functionality might be the right thing to do even in the long run. ia64: That's an hopeless case, as I doubt that anyone has the stomach to rewrite the homebrewn dynamic allocation facilities. I stared at it for a couple of hours and gave up. The create/destroy_irq mess could be made private to itanic right away if there wouldn't be the iommu/dmar driver being shared with x86. So to do that I'm going to add a separate ia64 specific implementation later in order not to deep-six itanic right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Grant Likely <grant.likely@linaro.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/20140507154334.208629358@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-04-28genirq: x86: Ensure that dynamic irq allocation does not conflictThomas Gleixner
On x86 the allocation of irq descriptors may allocate interrupts which are in the range of the GSI interrupts. That's wrong as those interrupts are hardwired and we don't have the irq domain translation like PPC. So one of these interrupts can be hooked up later to one of the devices which are hard wired to it and the io_apic init code for that particular interrupt line happily reuses that descriptor with a completely different configuration so hell breaks lose. Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs, except for a few usage sites which have not yet blown up in our face for whatever reason. But for drivers which need an irq range, like the GPIO drivers, we have no limit in place and we don't want to expose such a detail to a driver. To cure this introduce a function which an architecture can implement to impose a lower bound on the dynamic interrupt allocations. Implement it for x86 and set the lower bound to nr_gsi_irqs, which is the end of the hardwired interrupt space, so all dynamic allocations happen above. That not only allows the GPIO driver to work sanely, it also protects the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and htirq code. They need to be cleaned up as well, but that's a separate issue. Reported-by: Jin Yao <yao.jin@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Mathias Nyman <mathias.nyman@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Krogerus Heikki <heikki.krogerus@intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-04genirq: Add a kstat helper to increment irq statsThomas Gleixner
There is a common pattern all over the place: kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq)); This results in a call to core code anyway. So provide a function which does the same thing in core. While at it, replace the butt ugly macro with an inline. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140223212737.422068876@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-02-11genirq: Add missing irq_to_desc export for CONFIG_SPARSE_IRQ=nPaul Gortmaker
In allmodconfig builds for sparc and any other arch which does not set CONFIG_SPARSE_IRQ, the following will be seen at modpost: CC [M] lib/cpu-notifier-error-inject.o CC [M] lib/pm-notifier-error-inject.o ERROR: "irq_to_desc" [drivers/gpio/gpio-mcp23s08.ko] undefined! make[2]: *** [__modpost] Error 1 This happens because commit 3911ff30f5 ("genirq: export handle_edge_irq() and irq_to_desc()") added one export for it, but there were actually two instances of it, in an if/else clause for CONFIG_SPARSE_IRQ. Add the second one. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: stable@vger.kernel.org # 3.4+ Link: http://lkml.kernel.org/r/1392057610-11514-1-git-send-email-paul.gortmaker@windriver.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-05-15genirq: export handle_edge_irq() and irq_to_desc()Jiri Kosina
Export handle_edge_irq() and irq_to_desc() to modules to allow them to do things such as __irq_set_handler_locked(...., handle_edge_irq); This fixes ERROR: "handle_edge_irq" [drivers/gpio/gpio-pch.ko] undefined! ERROR: "irq_to_desc" [drivers/gpio/gpio-pch.ko] undefined! when gpio-pch is being built as a module. This was introduced by commit df9541a60af0 ("gpio: pch9: Use proper flow type handlers") that added __irq_set_handler_locked(d->irq, handle_edge_irq); but handle_edge_irq() was not exported for modules (and inlined __irq_set_handler_locked() requires irq_to_desc() exported as well) Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31irq: don't put module.h into irq.h for tracking irqgen modules.Paul Gortmaker
Recent commit "irq: Track the owner of irq descriptor" in commit ID b6873807a7143b7 placed module.h into linux/irq.h but we are trying to limit module.h inclusion to just C files that really need it, due to its size and number of children includes. This targets just reversing that include. Add in the basic "struct module" since that is all we really need to ensure things compile. In theory, b687380 should have added the module.h include to the irqdesc.h header as well, but the implicit module.h everywhere presence masked this from showing up. So give it the "struct module" as well. As for the C files, irqdesc.c is only using THIS_MODULE, so it does not need module.h - give it export.h instead. The C file irq/manage.c is now (as of b687380) using try_module_get and module_put and so it needs module.h (which it already has). Also convert the irq_alloc_descs variants to macros, since all they really do is is call the __irq_alloc_descs primitive. This avoids including export.h and no debug info is lost. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-03genirq: Add support for per-cpu dev_id interruptsMarc Zyngier
The ARM GIC interrupt controller offers per CPU interrupts (PPIs), which are usually used to connect local timers to each core. Each CPU has its own private interface to the GIC, and only sees the PPIs that are directly connect to it. While these timers are separate devices and have a separate interrupt line to a core, they all use the same IRQ number. For these devices, request_irq() is not the right API as it assumes that an IRQ number is visible by a number of CPUs (through the affinity setting), but makes it very awkward to express that an IRQ number can be handled by all CPUs, and yet be a different interrupt line on each CPU, requiring a different dev_id cookie to be passed back to the handler. The *_percpu_irq() functions is designed to overcome these limitations, by providing a per-cpu dev_id vector: int request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); void free_percpu_irq(unsigned int, void __percpu *); int setup_percpu_irq(unsigned int irq, struct irqaction *new); void remove_percpu_irq(unsigned int irq, struct irqaction *act); void enable_percpu_irq(unsigned int irq); void disable_percpu_irq(unsigned int irq); The API has a number of limitations: - no interrupt sharing - no threading - common handler across all the CPUs Once the interrupt is requested using setup_percpu_irq() or request_percpu_irq(), it must be enabled by each core that wishes its local interrupt to be delivered. Based on an initial patch by Thomas Gleixner. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-08-18irqdesc: fix new kernel-doc warningRandy Dunlap
Fix kernel-doc warning in irqdesc.c: Warning(kernel/irq/irqdesc.c:353): No description found for parameter 'owner' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-28irq: Track the owner of irq descriptorSebastian Andrzej Siewior
Interrupt descriptors can be allocated from modules. The interrupts are used by other modules, but we have no refcount on the module which provides the interrupts and there is no way to establish one on the device level as the interrupt using module is agnostic to the fact that the interrupt is provided by a module rather than by some builtin interrupt controller. To prevent removal of the interrupt providing module, we can track the owner of the interrupt descriptor, which also provides the relevant irq chip functions in the irq descriptor. request/setup_irq() can now acquire a refcount on the owner module to prevent unloading. free_irq() drops the refcount. Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Link: http://lkml.kernel.org/r/20110711101731.GA13804@Chamillionaire.breakpoint.cc Signed-off-by: Thomas Gleixner <tglx@linutronix.de>