linux/kernel/irq/Kconfig

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menu "IRQ subsystem"
# Options selectable by the architecture code
# Make sparse irq Kconfig switch below available
config MAY_HAVE_SPARSE_IRQ
bool
# Legacy support, required for itanic
config GENERIC_IRQ_LEGACY
bool
# Enable the generic irq autoprobe mechanism
config GENERIC_IRQ_PROBE
bool
# Use the generic /proc/interrupts implementation
config GENERIC_IRQ_SHOW
bool
# Print level/edge extra information
config GENERIC_IRQ_SHOW_LEVEL
bool
# Supports effective affinity mask
config GENERIC_IRQ_EFFECTIVE_AFF_MASK
bool
genirq: Provide generic hwirq allocation facility 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>
2014-05-07 15:44:05 +00:00
# Facility to allocate a hardware interrupt. This is legacy support
# and should not be used in new code. Use irq domains instead.
config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
bool
# Support for delayed migration from interrupt context
config GENERIC_PENDING_IRQ
bool
# Support for generic irq migrating off cpu before the cpu is offline.
config GENERIC_IRQ_MIGRATION
bool
# Alpha specific irq affinity mechanism
config AUTO_IRQ_AFFINITY
bool
# Tasklet based software resend for pending interrupts on enable_irq()
config HARDIRQS_SW_RESEND
bool
# Preflow handler support for fasteoi (sparc64)
config IRQ_PREFLOW_FASTEOI
bool
# Edge style eoi based handler (cell)
config IRQ_EDGE_EOI_HANDLER
bool
# Generic configurable interrupt chip implementation
config GENERIC_IRQ_CHIP
bool
select IRQ_DOMAIN
# Generic irq_domain hw <--> linux irq number translation
config IRQ_DOMAIN
bool
# Support for simulated interrupts
config IRQ_SIM
bool
select IRQ_WORK
irqdomain: Introduce new interfaces to support hierarchy irqdomains We plan to use hierarchy irqdomain to suppport CPU vector assignment, interrupt remapping controller, IO-APIC controller, MSI interrupt and hypertransport interrupt etc on x86 platforms. So extend irqdomain interfaces to support hierarchy irqdomain. There are already many clients of current irqdomain interfaces. To minimize the changes, we choose to introduce new version 2 interfaces to support hierarchy instead of extending existing irqdomain interfaces. According to Thomas's suggestion, the most important design decision is to build hierarchy struct irq_data to support hierarchy irqdomain, so hierarchy irqdomain related data could be saved in struct irq_data. With support of hierarchy irq_data, we could also support stacked irq_chips. This is most useful in case of set_affinity(). The new hierarchy irqdomain introduces following interfaces: 1) irq_domain_alloc_irqs()/irq_domain_free_irqs(): allocate/release IRQ and related resources. 2) __irq_domain_alloc_irqs(): a special version to support legacy IRQs. 3) irq_domain_activate_irq()/irq_domain_deactivate_irq(): program interrupt controllers to activate/deactivate interrupt. There are also several help functions to ease irqdomain implemenations: 1) irq_domain_get_irq_data(): get irq_data associated with a specific irqdomain. 2) irq_domain_set_hwirq_and_chip(): save irqdomain specific data into irq_data. 3) irq_domain_alloc_irqs_parent()/irq_domain_free_irqs_parent(): invoke parent irqdomain's alloc/free callbacks. We also changed irq_startup()/irq_shutdown() to invoke irq_domain_activate_irq()/irq_domain_deactivate_irq() to program interrupt controller when start/stop interrupts. [ tglx: Folded parts of the later patch series in ] Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Grant Likely <grant.likely@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Yingjoe Chen <yingjoe.chen@mediatek.com> Cc: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-06 14:20:14 +00:00
# Support for hierarchical irq domains
config IRQ_DOMAIN_HIERARCHY
bool
select IRQ_DOMAIN
# Support for hierarchical fasteoi+edge and fasteoi+level handlers
config IRQ_FASTEOI_HIERARCHY_HANDLERS
bool
# Generic IRQ IPI support
config GENERIC_IRQ_IPI
bool
# Generic MSI interrupt support
config GENERIC_MSI_IRQ
bool
# Generic MSI hierarchical interrupt domain support
config GENERIC_MSI_IRQ_DOMAIN
bool
select IRQ_DOMAIN_HIERARCHY
select GENERIC_MSI_IRQ
genirq: Add irq_domain-aware core IRQ handler 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>
2014-08-26 10:03:16 +00:00
config HANDLE_DOMAIN_IRQ
bool
genirq/timings: Add infrastructure to track the interrupt timings 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: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: 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/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org
2017-06-23 14:11:07 +00:00
config IRQ_TIMINGS
bool
genirq: Implement bitmap matrix allocator Implement the infrastructure for a simple bitmap based allocator, which will replace the x86 vector allocator. It's in the core code as other architectures might be able to reuse/extend it. For now it only implements allocations for single CPUs, but it's simple to add multi CPU allocation support if required. The concept is rather simple: Global information: system_vector bitmap global accounting PerCPU information: allocation bitmap managed allocation bitmap local accounting The system vector bitmap is used to exclude vectors system wide from the allocation space. The allocation bitmap is used to keep track of per cpu used vectors. The managed allocation bitmap is used to reserve vectors for managed interrupts. When a regular (non managed) interrupt allocation happens then the following rule applies: tmpmap = system_map | alloc_map | managed_map find_zero_bit(tmpmap) Oring the bitmaps together gives the real available space. The same rule applies for reserving a managed interrupt vector. But contrary to the regular interrupts the reservation only marks the bit in the managed map and therefor excludes it from the regular allocations. The managed map is only cleaned out when the a managed interrupt is completely released and it stays alive accross CPU offline/online operations. For managed interrupt allocations the rule is: tmpmap = managed_map & ~alloc_map find_first_bit(tmpmap) This returns the first bit which is in the managed map, but not yet allocated in the allocation map. The allocation marks it in the allocation map and hands it back to the caller for use. The rest of the code are helper functions to handle the various requirements and the accounting which are necessary to replace the x86 vector allocation code. The result is a single patch as the evolution of this infrastructure cannot be represented in bits and pieces. 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: Chris Metcalf <cmetcalf@mellanox.com> Cc: Len Brown <lenb@kernel.org> Link: https://lkml.kernel.org/r/20170913213153.185437174@linutronix.de
2017-09-13 21:29:14 +00:00
config GENERIC_IRQ_MATRIX_ALLOCATOR
bool
config IRQ_DOMAIN_DEBUG
bool "Expose hardware/virtual IRQ mapping via debugfs"
depends on IRQ_DOMAIN && DEBUG_FS
help
This option will show the mapping relationship between hardware irq
numbers and Linux irq numbers. The mapping is exposed via debugfs
in the file "irq_domain_mapping".
If you don't know what this means you don't need it.
# Support forced irq threading
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-23 23:52:23 +00:00
config IRQ_FORCED_THREADING
bool
config SPARSE_IRQ
bool "Support sparse irq numbering" if MAY_HAVE_SPARSE_IRQ
---help---
Sparse irq numbering is useful for distro kernels that want
to define a high CONFIG_NR_CPUS value but still want to have
low kernel memory footprint on smaller machines.
( Sparse irqs can also be beneficial on NUMA boxes, as they spread
out the interrupt descriptors in a more NUMA-friendly way. )
If you don't know what to do here, say N.
genirq/debugfs: Add proper debugfs interface 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>
2017-06-19 23:37:17 +00:00
config GENERIC_IRQ_DEBUGFS
bool "Expose irq internals in debugfs"
depends on DEBUG_FS
default n
---help---
Exposes internal state information through debugfs. Mostly for
developers and debugging of hard to diagnose interrupt problems.
If you don't know what to do here, say N.
endmenu