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2020-07-27genirq/debugfs: Add missing irqchip flagsMarc Zyngier1-0/+5
Recently introduced irqchip flags lack the corresponding printouts in debugfs. Add them. Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/874kpvydxc.wl-maz@kernel.org
2020-03-08genirq: Provide interrupt injection mechanismThomas Gleixner1-33/+1
Error injection mechanisms need a half ways safe way to inject interrupts as invoking generic_handle_irq() or the actual device interrupt handler directly from e.g. a debugfs write is not guaranteed to be safe. On x86 generic_handle_irq() is unsafe due to the hardware trainwreck which is the base of x86 interrupt delivery and affinity management. Move the irq debugfs injection code into a separate function which can be used by error injection code as well. The implementation prevents at least that state is corrupted, but it cannot close a very tiny race window on x86 which might result in a stale and not serviced device interrupt under very unlikely circumstances. This is explicitly for debugging and testing and not for production use or abuse in random driver code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lkml.kernel.org/r/20200306130623.990928309@linutronix.de
2020-03-08genirq: Add return value to check_irq_resend()Thomas Gleixner1-2/+1
In preparation for an interrupt injection interface which can be used safely by error injection mechanisms. e.g. PCI-E/ AER, add a return value to check_irq_resend() so errors can be propagated to the caller. Split out the software resend code so the ugly #ifdef in check_irq_resend() goes away and the whole thing becomes readable. Fix up the caller in debugfs. The caller in irq_startup() does not care about the return value as this is unconditionally invoked for all interrupts and the resend is best effort anyway. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lkml.kernel.org/r/20200306130623.775200917@linutronix.de
2020-03-08genirq/debugfs: Add missing sanity checks to interrupt injectionThomas Gleixner1-2/+9
Interrupts cannot be injected when the interrupt is not activated and when a replay is already in progress. Fixes: 536e2e34bd00 ("genirq/debugfs: Triggering of interrupts from userspace") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20200306130623.500019114@linutronix.de
2020-02-01x86/apic/msi: Plug non-maskable MSI affinity raceThomas Gleixner1-0/+1
Evan tracked down a subtle race between the update of the MSI message and the device raising an interrupt internally on PCI devices which do not support MSI masking. The update of the MSI message is non-atomic and consists of either 2 or 3 sequential 32bit wide writes to the PCI config space. - Write address low 32bits - Write address high 32bits (If supported by device) - Write data When an interrupt is migrated then both address and data might change, so the kernel attempts to mask the MSI interrupt first. But for MSI masking is optional, so there exist devices which do not provide it. That means that if the device raises an interrupt internally between the writes then a MSI message is sent built from half updated state. On x86 this can lead to spurious interrupts on the wrong interrupt vector when the affinity setting changes both address and data. As a consequence the device interrupt can be lost causing the device to become stuck or malfunctioning. Evan tried to handle that by disabling MSI accross an MSI message update. That's not feasible because disabling MSI has issues on its own: If MSI is disabled the PCI device is routing an interrupt to the legacy INTx mechanism. The INTx delivery can be disabled, but the disablement is not working on all devices. Some devices lose interrupts when both MSI and INTx delivery are disabled. Another way to solve this would be to enforce the allocation of the same vector on all CPUs in the system for this kind of screwed devices. That could be done, but it would bring back the vector space exhaustion problems which got solved a few years ago. Fortunately the high address (if supported by the device) is only relevant when X2APIC is enabled which implies interrupt remapping. In the interrupt remapping case the affinity setting is happening at the interrupt remapping unit and the PCI MSI message is programmed only once when the PCI device is initialized. That makes it possible to solve it with a two step update: 1) Target the MSI msg to the new vector on the current target CPU 2) Target the MSI msg to the new vector on the new target CPU In both cases writing the MSI message is only changing a single 32bit word which prevents the issue of inconsistency. After writing the final destination it is necessary to check whether the device issued an interrupt while the intermediate state #1 (new vector, current CPU) was in effect. This is possible because the affinity change is always happening on the current target CPU. The code runs with interrupts disabled, so the interrupt can be detected by checking the IRR of the local APIC. If the vector is pending in the IRR then the interrupt is retriggered on the new target CPU by sending an IPI for the associated vector on the target CPU. This can cause spurious interrupts on both the local and the new target CPU. 1) If the new vector is not in use on the local CPU and the device affected by the affinity change raised an interrupt during the transitional state (step #1 above) then interrupt entry code will ignore that spurious interrupt. The vector is marked so that the 'No irq handler for vector' warning is supressed once. 2) If the new vector is in use already on the local CPU then the IRR check might see an pending interrupt from the device which is using this vector. The IPI to the new target CPU will then invoke the handler of the device, which got the affinity change, even if that device did not issue an interrupt 3) If the new vector is in use already on the local CPU and the device affected by the affinity change raised an interrupt during the transitional state (step #1 above) then the handler of the device which uses that vector on the local CPU will be invoked. expose issues in device driver interrupt handlers which are not prepared to handle a spurious interrupt correctly. This not a regression, it's just exposing something which was already broken as spurious interrupts can happen for a lot of reasons and all driver handlers need to be able to deal with them. Reported-by: Evan Green <evgreen@chromium.org> Debugged-by: Evan Green <evgreen@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Evan Green <evgreen@chromium.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87imkr4s7n.fsf@nanos.tec.linutronix.de
2019-04-09treewide: Switch printk users from %pf and %pF to %ps and %pS, respectivelySakari Ailus1-1/+1
%pF and %pf are functionally equivalent to %pS and %ps conversion specifiers. The former are deprecated, therefore switch the current users to use the preferred variant. The changes have been produced by the following command: git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \ while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done And verifying the result. Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: linux-arm-kernel@lists.infradead.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: xen-devel@lists.xenproject.org Cc: linux-acpi@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Cc: linux-mmc@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: linux-pci@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: linux-btrfs@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: linux-mm@kvack.org Cc: ceph-devel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: David Sterba <dsterba@suse.com> (for btrfs) Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c) Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci) Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-02-23Merge tag 'irqchip-5.1' of ↵Thomas Gleixner1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core Pull irqchip updates from Marc Zyngier - Core pseudo-NMI handling code - Allow the default irq domain to be retrieved - A new interrupt controller for the Loongson LS1X platform - Affinity support for the SiFive PLIC - Better support for the iMX irqsteer driver - NUMA aware memory allocations for GICv3 - A handful of other fixes (i8259, GICv3, PLIC)
2019-02-05genirq: Provide basic NMI management for interrupt linesJulien Thierry1-2/+4
Add functionality to allocate interrupt lines that will deliver IRQs as Non-Maskable Interrupts. These allocations are only successful if the irqchip provides the necessary support and allows NMI delivery for the interrupt line. Interrupt lines allocated for NMI delivery must be enabled/disabled through enable_nmi/disable_nmi_nosync to keep their state consistent. To treat a PERCPU IRQ as NMI, the interrupt must not be shared nor threaded, the irqchip directly managing the IRQ must be the root irqchip and the irqchip cannot be behind a slow bus. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-01-29genirq/debugfs: No need to check return value of debugfs_create functionsGreg Kroah-Hartman1-2/+0
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: https://lkml.kernel.org/r/20190122152151.16139-50-gregkh@linuxfoundation.org
2018-06-22genirq/debugfs: Add missing IRQCHIP_SUPPORTS_LEVEL_MSI debugMarc Zyngier1-0/+1
Debug is missing the IRQCHIP_SUPPORTS_LEVEL_MSI debug entry, making debugfs slightly less useful. Take this opportunity to also add a missing comment in the definition of IRQCHIP_SUPPORTS_LEVEL_MSI. Fixes: 6988e0e0d283 ("genirq/msi: Limit level-triggered MSI to platform devices") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: Sumit Garg <sumit.garg@linaro.org> Link: https://lkml.kernel.org/r/20180622095254.5906-2-marc.zyngier@arm.com
2018-03-20genirq: Remove license boilerplate/referencesThomas Gleixner1-5/+2
Now that SPDX identifiers are in place, remove the boilerplate or references. The change in timings.c has been acked by the author. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Link: https://lkml.kernel.org/r/20180314212030.668321222@linutronix.de
2018-03-20genirq: Add missing SPDX identifiersThomas Gleixner1-0/+1
Add SPDX identifiers to files - which contain an explicit license boiler plate or reference - which do not contain a license reference and were not updated in the initial SPDX conversion because the license was deduced by the scanners via EXPORT_SYMBOL_GPL as GPL2.0 only. [ tglx: Moved adding identifiers from the patch which removes the references/boilerplate ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Link: https://lkml.kernel.org/r/20180314212030.668321222@linutronix.de
2017-12-29genirq: Introduce IRQD_CAN_RESERVE flagThomas Gleixner1-0/+1
Add a new flag to mark interrupts which can use reservation mode. This is going to be used in subsequent patches to disable reservation mode for a certain class of MSI devices. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Alexandru Chirvasitu <achirvasub@gmail.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Mikael Pettersson <mikpelinux@gmail.com> Cc: Josh Poulson <jopoulso@microsoft.com> Cc: Mihai Costache <v-micos@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-pci@vger.kernel.org Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Simon Xiao <sixiao@microsoft.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Cc: Jork Loeser <Jork.Loeser@microsoft.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: devel@linuxdriverproject.org Cc: KY Srinivasan <kys@microsoft.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Sakari Ailus <sakari.ailus@intel.com>, Cc: linux-media@vger.kernel.org
2017-09-25irqdomain/debugfs: Provide domain specific debug callbackThomas Gleixner1-0/+2
Some interrupt domains like the X86 vector domain has special requirements for debugging, like showing the vector usage on the CPUs. Add a callback to the irqdomain ops which can be filled in by domains which require it and add conditional invocations to the irqdomain and the per irq debug files. 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/20170913213152.512937505@linutronix.de
2017-09-25genirq/msi: Capture device name for debugfsThomas Gleixner1-0/+10
For debugging the allocation of unused or potentially leaked interrupt descriptor it's helpful to have some information about the site which allocated them. In case of MSI this is simple because the caller hands the device struct pointer into the domain allocation function. Duplicate the device name and show it in the debugfs entry of the interrupt 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/20170913213152.433038426@linutronix.de
2017-08-18genirq/debugfs: Triggering of interrupts from userspaceMarc Zyngier1-1/+49
When developing new (and therefore buggy) interrupt related code, it can sometimes be useful to inject interrupts without having to rely on a device to actually generate them. This functionnality relies either on the irqchip driver to expose a irq_set_irqchip_state(IRQCHIP_STATE_PENDING) callback, or on the core code to be able to retrigger a (edge-only) interrupt. To use this feature: echo -n trigger > /sys/kernel/debug/irq/irqs/IRQNUM WARNING: This is DANGEROUS, and strictly a debug feature. Do not use it on a production system. Your HW is likely to catch fire, your data to be corrupted, and reporting this will make you look an even bigger fool than the idiot who wrote this patch. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170818081156.9264-1-marc.zyngier@arm.com
2017-06-24genirq/debugfs: Remove pointless NULL pointer checkThomas Gleixner1-7/+0
debugfs_remove() has it's own NULL pointer check. Remove the conditional and make irq_remove_debugfs_entry() an inline helper Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-22genirq: Introduce IRQD_SINGLE_TARGET flagThomas Gleixner1-0/+1
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: 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/20170619235447.352343969@linutronix.de
2017-06-22genirq: Introduce effective affinity maskThomas Gleixner1-0/+4
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/debugfs: Add proper debugfs interfaceThomas Gleixner1-0/+215
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>