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* genirq: Return the IRQ name from free_irq()Christoph Hellwig2017-04-181-1/+1
| | | | | | | | This allows callers to get back at them instead of having to store it in another variable. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
* genirq/affinity: Handle pre/post vectors in irq_create_affinity_masks()Christoph Hellwig2016-11-091-2/+2
| | | | | | | | | | | | | | | | | | | Only calculate the affinity for the main I/O vectors, and skip the pre or post vectors specified by struct irq_affinity. Also remove the irq_affinity cpumask argument that has never been used. If we ever need it in the future we can pass it through struct irq_affinity. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-4-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq/affinity: Handle pre/post vectors in irq_calc_affinity_vectors()Christoph Hellwig2016-11-091-2/+2
| | | | | | | | | | | | | | | | | Only calculate the affinity for the main I/O vectors, and skip the pre or post vectors specified by struct irq_affinity. Also remove the irq_affinity cpumask argument that has never been used. If we ever need it in the future we can pass it through struct irq_affinity. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-3-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq/affinity: Introduce struct irq_affinityChristoph Hellwig2016-11-091-0/+12
| | | | | | | | | | | | | | | | | | | | | | | Some drivers (various network and RDMA adapter for example) have a MSI-X vector layout where most of the vectors are used for I/O queues and should have CPU affinity assigned to them, but some (usually 1 but sometimes more) at the beginning or end are used for low-performance admin or configuration work and should not have any explicit affinity assigned to them. Add a new irq_affinity structure, which will be passed through a variant of pci_irq_alloc_vectors that allows to specify these requirements (and is extensible to any future quirks in that area) so that the core IRQ affinity algorithm can take this quirks into account. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-2-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq/affinity: Remove old irq spread infrastructureThomas Gleixner2016-09-141-7/+0
| | | | | | | | | | | | | | No more users. 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/1473862739-15032-5-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq/affinity: Provide smarter irq spreading infrastructureThomas Gleixner2016-09-141-0/+15
| | | | | | | | | | | | | | | | | | | | The current irq spreading infrastructure is just looking at a cpumask and tries to spread the interrupts over the mask. Thats suboptimal as it does not take numa nodes into account. Change the logic so the interrupts are spread across numa nodes and inside the nodes. If there are more cpus than vectors per node, then we set the affinity to several cpus. If HT siblings are available we take that into account and try to set all siblings to a single vector. 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/1473862739-15032-3-git-send-email-hch@lst.de
* genirq: Add a helper to spread an affinity mask for MSI/MSI-X vectorsChristoph Hellwig2016-07-041-0/+8
| | | | | | | | | | | | | | | | | | This is lifted from the blk-mq code and adopted to use the affinity mask concept just introduced in the irq handling code. It tries to keep the algorithm the same as the one current used by blk-mq, but improvements like assining vectors on a per-node basis instead of just per sibling are possible with this simple move and refactoring. Signed-off-by: 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/1467621574-8277-7-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* arch, ftrace: for KASAN put hard/soft IRQ entries into separate sectionsAlexander Potapenko2016-03-251-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to <linux/interrupt.h> so that the users don't need to pull in <linux/ftrace.h>. Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/ACPI/PCI: Recognize that Interrupt Line 255 means "not connected"Chen Fan2016-03-091-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per the x86-specific footnote to PCI spec r3.0, sec 6.2.4, the value 255 in the Interrupt Line register means "unknown" or "no connection." Previously, when we couldn't derive an IRQ from the _PRT, we fell back to using the value from Interrupt Line as an IRQ. It's questionable whether we should do that at all, but the spec clearly suggests we shouldn't do it for the value 255 on x86. Calling request_irq() with IRQ 255 may succeed, but the driver won't receive any interrupts. Or, if IRQ 255 is shared with another device, it may succeed, and the driver's ISR will be called at random times when the *other* device interrupts. Or it may fail if another device is using IRQ 255 with incompatible flags. What we *want* is for request_irq() to fail predictably so the driver can fall back to polling. On x86, assume 255 in the Interrupt Line means the INTx line is not connected. In that case, set dev->irq to IRQ_NOTCONNECTED so request_irq() will fail gracefully with -ENOTCONN. We found this problem on a system where Secure Boot firmware assigned Interrupt Line 255 to an i801_smbus device and another device was already using MSI-X IRQ 255. This was in v3.10, where i801_probe() fails if request_irq() fails: i801_smbus 0000:00:1f.3: enabling device (0140 -> 0143) i801_smbus 0000:00:1f.3: can't derive routing for PCI INT C i801_smbus 0000:00:1f.3: PCI INT C: no GSI genirq: Flags mismatch irq 255. 00000080 (i801_smbus) vs. 00000000 (megasa) CPU: 0 PID: 2487 Comm: kworker/0:1 Not tainted 3.10.0-229.el7.x86_64 #1 Hardware name: FUJITSU PRIMEQUEST 2800E2/D3736, BIOS PRIMEQUEST 2000 Serie5 Call Trace: dump_stack+0x19/0x1b __setup_irq+0x54a/0x570 request_threaded_irq+0xcc/0x170 i801_probe+0x32f/0x508 [i2c_i801] local_pci_probe+0x45/0xa0 i801_smbus 0000:00:1f.3: Failed to allocate irq 255: -16 i801_smbus: probe of 0000:00:1f.3 failed with error -16 After aeb8a3d16ae0 ("i2c: i801: Check if interrupts are disabled"), i801_probe() will fall back to polling if request_irq() fails. But we still need this patch because request_irq() may succeed or fail depending on other devices in the system. If request_irq() fails, i801_smbus will work by falling back to polling, but if it succeeds, i801_smbus won't work because it expects interrupts that it may not receive. Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Merge tag 'for-linus' of ↵Linus Torvalds2016-01-231-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma Pull rdma updates from Doug Ledford: "Initial roundup of 4.5 merge window patches - Remove usage of ib_query_device and instead store attributes in ib_device struct - Move iopoll out of block and into lib, rename to irqpoll, and use in several places in the rdma stack as our new completion queue polling library mechanism. Update the other block drivers that already used iopoll to use the new mechanism too. - Replace the per-entry GID table locks with a single GID table lock - IPoIB multicast cleanup - Cleanups to the IB MR facility - Add support for 64bit extended IB counters - Fix for netlink oops while parsing RDMA nl messages - RoCEv2 support for the core IB code - mlx4 RoCEv2 support - mlx5 RoCEv2 support - Cross Channel support for mlx5 - Timestamp support for mlx5 - Atomic support for mlx5 - Raw QP support for mlx5 - MAINTAINERS update for mlx4/mlx5 - Misc ocrdma, qib, nes, usNIC, cxgb3, cxgb4, mlx4, mlx5 updates - Add support for remote invalidate to the iSER driver (pushed through the RDMA tree due to dependencies, acknowledged by nab) - Update to NFSoRDMA (pushed through the RDMA tree due to dependencies, acknowledged by Bruce)" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (169 commits) IB/mlx5: Unify CQ create flags check IB/mlx5: Expose Raw Packet QP to user space consumers {IB, net}/mlx5: Move the modify QP operation table to mlx5_ib IB/mlx5: Support setting Ethernet priority for Raw Packet QPs IB/mlx5: Add Raw Packet QP query functionality IB/mlx5: Add create and destroy functionality for Raw Packet QP IB/mlx5: Refactor mlx5_ib_qp to accommodate other QP types IB/mlx5: Allocate a Transport Domain for each ucontext net/mlx5_core: Warn on unsupported events of QP/RQ/SQ net/mlx5_core: Add RQ and SQ event handling net/mlx5_core: Export transport objects IB/mlx5: Expose CQE version to user-space IB/mlx5: Add CQE version 1 support to user QPs and SRQs IB/mlx5: Fix data validation in mlx5_ib_alloc_ucontext IB/sa: Fix netlink local service GFP crash IB/srpt: Remove redundant wc array IB/qib: Improve ipoib UD performance IB/mlx4: Advertise RoCE v2 support IB/mlx4: Create and use another QP1 for RoCEv2 IB/mlx4: Enable send of RoCE QP1 packets with IP/UDP headers ...
| * irq_poll: make blk-iopoll available outside the block layerChristoph Hellwig2015-12-111-1/+1
| | | | | | | | | | | | | | | | The new name is irq_poll as iopoll is already taken. Better suggestions welcome. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
* | genirq: Implement irq_percpu_is_enabled()Thomas Petazzoni2015-12-081-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Certain interrupt controller drivers have a register set that does not make it easy to save/restore the mask of enabled/disabled interrupts at suspend/resume time. At resume time, such drivers rely on the core kernel irq subsystem to tell whether such or such interrupt is enabled or not, in order to restore the proper state in the interrupt controller register. While the irqd_irq_disabled() provides the relevant information for global interrupts, there is no similar function to query the enabled/disabled state of a per-CPU interrupt. Therefore, this commit complements the percpu_irq API with an irq_percpu_is_enabled() function. [ tglx: Simplified the implementation and added kerneldoc ] Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Tawfik Bayouk <tawfik@marvell.com> Cc: Nadav Haklai <nadavh@marvell.com> Cc: Lior Amsalem <alior@marvell.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Cc: Gregory Clement <gregory.clement@free-electrons.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1445347435-2333-2-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Handle force threading of irqs with primary and thread handlerThomas Gleixner2015-09-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Force threading of interrupts does not really deal with interrupts which are requested with a primary and a threaded handler. The current policy is to leave them alone and let the primary handler run in interrupt context, but we set the ONESHOT flag for those interrupts as well. Kohji Okuno debugged a problem with the SDHCI driver where the interrupt thread waits for a hardware interrupt to trigger, which can't work well because the hardware interrupt is masked due to the ONESHOT flag being set. He proposed to set the ONESHOT flag only if the interrupt does not provide a thread handler. Though that does not work either because these interrupts can be shared. So the other interrupt would rightfully get the ONESHOT flag set and therefor the same situation would happen again. To deal with this proper, we need to force thread the primary handler of such interrupts as well. That means that the primary interrupt handler is treated as any other primary interrupt handler which is not marked IRQF_NO_THREAD. The threaded handler becomes a separate thread so the SDHCI flow logic can be handled gracefully. The same issue was reported against 4.1-rt. Reported-and-tested-by: Kohji Okuno <okuno.kohji@jp.panasonic.com> Reported-By: Michal Smucr <msmucr@gmail.com> Reported-and-tested-by: Nathan Sullivan <nathan.sullivan@ni.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1509211058080.5606@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: Remove hrtimer_start() return valueThomas Gleixner2015-04-221-3/+3
| | | | | | | | | | | | | | | No user was ever interested whether the timer was active or not when it was started. All abusers of the return value are gone, so get rid of it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203503.483556394@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: Get rid of hrtimer softirqThomas Gleixner2015-04-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | hrtimer softirq is a leftover from the initial implementation and serves only the purpose to handle the enqueueing of already expired timers in the high resolution timer mode. We discussed whether we change the return value and force all start sites to handle that the timer is already expired, but that would be a Herculean task and I'm not sure whether its a good idea to enforce that handling on everyone. A simpler solution is to enforce a timer interrupt instead of raising and scheduling a softirq. Just use the existing infrastructure to do so and remove all the softirq leftovers. The HRTIMER softirq enum is now unused, but kept around because trace parsers rely on the existing numbering. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.840834708@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Allow the irqchip state of an IRQ to be save/restoredMarc Zyngier2015-04-081-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a number of cases where a kernel subsystem may want to introspect the state of an interrupt at the irqchip level: - When a peripheral is shared between virtual machines, its interrupt state becomes part of the guest's state, and must be switched accordingly. KVM on arm/arm64 requires this for its guest-visible timer - Some GPIO controllers seem to require peeking into the interrupt controller they are connected to to report their internal state This seem to be a pattern that is common enough for the core code to try and support this without too many horrible hacks. Introduce a pair of accessors (irq_get_irqchip_state/irq_set_irqchip_state) to retrieve the bits that can be of interest to another subsystem: pending, active, and masked. - irq_get_irqchip_state returns the state of the interrupt according to a parameter set to IRQCHIP_STATE_PENDING, IRQCHIP_STATE_ACTIVE, IRQCHIP_STATE_MASKED or IRQCHIP_STATE_LINE_LEVEL. - irq_set_irqchip_state similarly sets the state of the interrupt. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Tested-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Abhijeet Dharmapurikar <adharmap@codeaurora.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Phong Vo <pvo@apm.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Tin Huynh <tnhuynh@apm.com> Cc: Y Vo <yvo@apm.com> Cc: Toan Le <toanle@apm.com> Cc: Bjorn Andersson <bjorn@kryo.se> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1426676484-21812-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'linus' into irq/core to get the GIC updates whichThomas Gleixner2015-04-081-1/+8
|\ | | | | | | | | | | | | conflict with pending GIC changes. Conflicts: drivers/usb/isp1760/isp1760-core.c
| * genirq / PM: Add flag for shared NO_SUSPEND interrupt linesRafael J. Wysocki2015-03-041-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It currently is required that all users of NO_SUSPEND interrupt lines pass the IRQF_NO_SUSPEND flag when requesting the IRQ or the WARN_ON_ONCE() in irq_pm_install_action() will trigger. That is done to warn about situations in which unprepared interrupt handlers may be run unnecessarily for suspended devices and may attempt to access those devices by mistake. However, it may cause drivers that have no technical reasons for using IRQF_NO_SUSPEND to set that flag just because they happen to share the interrupt line with something like a timer. Moreover, the generic handling of wakeup interrupts introduced by commit 9ce7a25849e8 (genirq: Simplify wakeup mechanism) only works for IRQs without any NO_SUSPEND users, so the drivers of wakeup devices needing to use shared NO_SUSPEND interrupt lines for signaling system wakeup generally have to detect wakeup in their interrupt handlers. Thus if they happen to share an interrupt line with a NO_SUSPEND user, they also need to request that their interrupt handlers be run after suspend_device_irqs(). In both cases the reason for using IRQF_NO_SUSPEND is not because the driver in question has a genuine need to run its interrupt handler after suspend_device_irqs(), but because it happens to share the line with some other NO_SUSPEND user. Otherwise, the driver would do without IRQF_NO_SUSPEND just fine. To make it possible to specify that condition explicitly, introduce a new IRQ action handler flag for shared IRQs, IRQF_COND_SUSPEND, that, when set, will indicate to the IRQ core that the interrupt user is generally fine with suspending the IRQ, but it also can tolerate handler invocations after suspend_device_irqs() and, in particular, it is capable of detecting system wakeup and triggering it as appropriate from its interrupt handler. That will allow us to work around a problem with a shared timer interrupt line on at91 platforms. Link: http://marc.info/?l=linux-kernel&m=142252777602084&w=2 Link: http://marc.info/?t=142252775300011&r=1&w=2 Link: https://lkml.org/lkml/2014/12/15/552 Reported-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com>
| * genirq / PM: better describe IRQF_NO_SUSPEND semanticsMark Rutland2015-02-261-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The IRQF_NO_SUSPEND flag is intended to be used for interrupts required to be enabled during the suspend-resume cycle. This mostly consists of IPIs and timer interrupts, potentially including chained irqchip interrupts if these are necessary to handle timers or IPIs. If an interrupt does not fall into one of the aforementioned categories, requesting it with IRQF_NO_SUSPEND is likely incorrect. Using IRQF_NO_SUSPEND does not guarantee that the interrupt can wake the system from a suspended state. For an interrupt to be able to trigger a wakeup, it may be necessary to program various components of the system. In these cases it is necessary to use {enable,disabled}_irq_wake. Unfortunately, several drivers assume that IRQF_NO_SUSPEND ensures that an IRQ can wake up the system, and the documentation can be read ambiguously w.r.t. this property. This patch updates the documentation regarding IRQF_NO_SUSPEND to make this caveat explicit, hopefully making future misuse rarer. Cleanup of existing misuse will occur as part of later patch series. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | genirq: Remove the deprecated 'IRQF_DISABLED' request_irq() flag entirelyValentin Rothberg2015-03-051-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The IRQF_DISABLED flag is a NOOP and has been scheduled for removal since Linux v2.6.36 by commit 6932bf37bed4 ("genirq: Remove IRQF_DISABLED from core code"). According to commit e58aa3d2d0cc ("genirq: Run irq handlers with interrupts disabled"), running IRQ handlers with interrupts enabled can cause stack overflows when the interrupt line of the issuing device is still active. This patch ends the grace period for IRQF_DISABLED (i.e., SA_INTERRUPT in older versions of Linux) and removes the definition and all remaining usages of this flag. There's still a few non-functional references left in the kernel source: - The bigger hunk in Documentation/scsi/ncr53c8xx.txt is removed entirely as IRQF_DISABLED is gone now; the usage in older kernel versions (including the old SA_INTERRUPT flag) should be discouraged. The trouble of using IRQF_SHARED is a general problem and not specific to any driver. - I left the reference in Documentation/PCI/MSI-HOWTO.txt untouched since it has already been removed in linux-next. - All remaining references are changelogs that I suggest to keep. Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Afzal Mohammed <afzal@ti.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Ewan Milne <emilne@redhat.com> Cc: Eyal Perry <eyalpe@mellanox.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Hongliang Tao <taohl@lemote.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Keerthy <j-keerthy@ti.com> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nishanth Menon <nm@ti.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Lambert <lambert.quentin@gmail.com> Cc: Rajendra Nayak <rnayak@ti.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Sricharan R <r.sricharan@ti.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Lindgren <tony@atomide.com> Cc: Zhou Wang <wangzhou1@hisilicon.com> Cc: iss_storagedev@hp.com Cc: linux-mips@linux-mips.org Cc: linux-mtd@lists.infradead.org Link: http://lkml.kernel.org/r/1425565425-12604-1-git-send-email-valentinrothberg@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | genirq: Provide disable_hardirq()Peter Zijlstra2015-02-181-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | For things like netpoll there is a need to disable an interrupt from atomic context. Currently netpoll uses disable_irq() which will sleep-wait on threaded handlers and thus forced_irqthreads breaks things. Provide disable_hardirq(), which uses synchronize_hardirq() to only wait for active hardirq handlers; also change synchronize_hardirq() to return the status of threaded handlers. This will allow one to try-disable an interrupt from atomic context, or in case of request_threaded_irq() to only wait for the hardirq part. Suggested-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Miller <davem@davemloft.net> Cc: Eyal Perry <eyalpe@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Quentin Lambert <lambert.quentin@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Link: http://lkml.kernel.org/r/20150205130623.GH5029@twins.programming.kicks-ass.net [ Fixed typos and such. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* linux/interrupt.h: remove the definition of unused tasklet_hi_enableQuentin Lambert2014-12-121-6/+0
| | | | | | Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com> Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* genirq: Simplify wakeup mechanismThomas Gleixner2014-09-011-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | Currently we suspend wakeup interrupts by lazy disabling them and check later whether the interrupt has fired, but that's not sufficient for suspend to idle as there is no way to check that once we transitioned into the CPU idle state. So we change the mechanism in the following way: 1) Leave the wakeup interrupts enabled across suspend 2) Add a check to irq_may_run() which is called at the beginning of each flow handler whether the interrupt is an armed wakeup source. This check is basically free as it just extends the existing check for IRQD_IRQ_INPROGRESS. So no new conditional in the hot path. If the IRQD_WAKEUP_ARMED flag is set, then the interrupt is disabled, marked as pending/suspended and the pm core is notified about the wakeup event. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ rjw: syscore.c and put irq_pm_check_wakeup() into pm.c ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2014-06-041-20/+26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull core irq updates from Thomas Gleixner: "The irq department delivers: - Another tree wide update to get rid of the horrible create_irq interface along with its even more horrible variants. That also gets rid of the last leftovers of the initial sparse irq hackery. arch/driver specific changes have been either acked or ignored. - A fix for the spurious interrupt detection logic with threaded interrupts. - A new ARM SoC interrupt controller - The usual pile of fixes and improvements all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) Documentation: brcmstb-l2: Add Broadcom STB Level-2 interrupt controller binding irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-2 interrupt controller genirq: Improve documentation to match current implementation ARM: iop13xx: fix msi support with sparse IRQ genirq: Provide !SMP stub for irq_set_affinity_notifier() irqchip: armada-370-xp: Move the devicetree binding documentation irqchip: gic: Use mask field in GICC_IAR genirq: Remove dynamic_irq mess ia64: Use irq_init_desc genirq: Replace dynamic_irq_init/cleanup genirq: Remove irq_reserve_irq[s] genirq: Replace reserve_irqs in core code s390: Avoid call to irq_reserve_irqs() s390: Remove pointless arch_show_interrupts() s390: pci: Check return value of alloc_irq_desc() proper sh: intc: Remove pointless irq_reserve_irqs() invocation x86, irq: Remove pointless irq_reserve_irqs() call genirq: Make create/destroy_irq() ia64 private tile: Use SPARSE_IRQ tile: pci: Use irq_alloc/free_hwirq() ...
| * Merge branch 'irq/for-net' into irq/coreThomas Gleixner2014-05-211-20/+26
| |\ | | | | | | | | | | | | | | | Reason: Import the change which might be pulled in from net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| | * genirq: Provide !SMP stub for irq_set_affinity_notifier()Eyal Perry2014-05-211-20/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of requiring each consumer of the IRQ affinity notifier to have themselves be explicitly dependent on CONFIG_SMP, make the definition of struct irq_affinity_notify to exist independently of that config option and introduce a stub for irq_set_affinity_notifier() under non SMP configuration. Fixes: 2eacc23 ("net/mlx4_core: Enforce irq affinity changes immediatly") Signed-off-by: Eyal Perry <eyalpe@mellanox.com> Signed-off-by: Amir Vadai <amirv@mellanox.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Yevgeny Petrilin <yevgenyp@mellanox.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: David S. Miller <davem@davemloft.net> Link: http://lkml.kernel.org/r/1400597820-30685-1-git-send-email-amirv@mellanox.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | Merge branch 'locking-core-for-linus' of ↵Linus Torvalds2014-06-031-4/+4
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull core locking updates from Ingo Molnar: "The main changes in this cycle were: - reduced/streamlined smp_mb__*() interface that allows more usecases and makes the existing ones less buggy, especially in rarer architectures - add rwsem implementation comments - bump up lockdep limits" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) rwsem: Add comments to explain the meaning of the rwsem's count field lockdep: Increase static allocations arch: Mass conversion of smp_mb__*() arch,doc: Convert smp_mb__*() arch,xtensa: Convert smp_mb__*() arch,x86: Convert smp_mb__*() arch,tile: Convert smp_mb__*() arch,sparc: Convert smp_mb__*() arch,sh: Convert smp_mb__*() arch,score: Convert smp_mb__*() arch,s390: Convert smp_mb__*() arch,powerpc: Convert smp_mb__*() arch,parisc: Convert smp_mb__*() arch,openrisc: Convert smp_mb__*() arch,mn10300: Convert smp_mb__*() arch,mips: Convert smp_mb__*() arch,metag: Convert smp_mb__*() arch,m68k: Convert smp_mb__*() arch,m32r: Convert smp_mb__*() arch,ia64: Convert smp_mb__*() ...
| * | arch: Mass conversion of smp_mb__*()Peter Zijlstra2014-04-181-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | genirq: Provide irq_force_affinity fallback for non-SMPArnd Bergmann2014-05-071-0/+5
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch 01f8fa4f01d "genirq: Allow forcing cpu affinity of interrupts" added an irq_force_affinity() function, and 30ccf03b4a6 "clocksource: Exynos_mct: Use irq_force_affinity() in cpu bringup" subsequently uses it. However, the driver can be used with CONFIG_SMP disabled, but the function declaration is only available for CONFIG_SMP, leading to this build error: drivers/clocksource/exynos_mct.c:431:3: error: implicit declaration of function 'irq_force_affinity' [-Werror=implicit-function-declaration] irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu)); This patch introduces a dummy helper function for the non-SMP case that always returns success, to get rid of the build error. Since the patches causing the problem are marked for stable backports, this one should be as well. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/5619084.0zmrrIUZLV@wuerfel Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | linux/interrupt.h: fix new kernel-doc warningsRandy Dunlap2014-04-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix new kernel-doc warnings in <linux/interrupt.h>: Warning(include/linux/interrupt.h:219): No description found for parameter 'cpumask' Warning(include/linux/interrupt.h:219): Excess function parameter 'mask' description in 'irq_set_affinity' Warning(include/linux/interrupt.h:236): No description found for parameter 'cpumask' Warning(include/linux/interrupt.h:236): Excess function parameter 'mask' description in 'irq_force_affinity' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Link: http://lkml.kernel.org/r/535DD2FD.7030804@infradead.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Allow forcing cpu affinity of interruptsThomas Gleixner2014-04-171-1/+34
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation of irq_set_affinity() refuses rightfully to route an interrupt to an offline cpu. But there is a special case, where this is actually desired. Some of the ARM SoCs have per cpu timers which require setting the affinity during cpu startup where the cpu is not yet in the online mask. If we can't do that, then the local timer interrupt for the about to become online cpu is routed to some random online cpu. The developers of the affected machines tried to work around that issue, but that results in a massive mess in that timer code. We have a yet unused argument in the set_affinity callbacks of the irq chips, which I added back then for a similar reason. It was never required so it got not used. But I'm happy that I never removed it. That allows us to implement a sane handling of the above scenario. So the affected SoC drivers can add the required force handling to their interrupt chip, switch the timer code to irq_force_affinity() and things just work. This does not affect any existing user of irq_set_affinity(). Tagged for stable to allow a simple fix of the affected SoC clock event drivers. Reported-and-tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Tomasz Figa <t.figa@samsung.com>, Cc: Daniel Lezcano <daniel.lezcano@linaro.org>, Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: linux-arm-kernel@lists.infradead.org, Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20140416143315.717251504@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Provide irq_wake_thread()Thomas Gleixner2014-02-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | In course of the sdhci/sdio discussion with Russell about killing the sdio kthread hackery we discovered the need to be able to wake an interrupt thread from software. The rationale for this is, that sdio hardware can lack proper interrupt support for certain features. So the driver needs to poll the status registers, but at the same time it needs to be woken up by an hardware interrupt. To be able to get rid of the home brewn kthread construct of sdio we need a way to wake an irq thread independent of an actual hardware interrupt. Provide an irq_wake_thread() function which wakes up the thread which is associated to a given dev_id. This allows sdio to invoke the irq thread from the hardware irq handler via the IRQ_WAKE_THREAD return value and provides a possibility to wake it via a timer for the polling scenarios. That allows to simplify the sdio logic significantly. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Chris Ball <chris@printf.net> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de
* genirq: Add devm_request_any_context_irq()Stephen Boyd2014-02-091-0/+5
| | | | | | | | | | | | Some drivers use request_any_context_irq() but there isn't a devm_* function for it. Add one so that these drivers don't need to explicitly free the irq on driver detach. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: linux-arm-kernel@lists.infradead.org Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Link: http://lkml.kernel.org/r/1388709460-19222-3-git-send-email-sboyd@codeaurora.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* softirq: use const char * const for softirq_to_name, whitespace neateningJoe Perches2014-01-271-1/+1
| | | | | | | | | | | | | | | | | Reduce data size a little. Reduce checkpatch noise. $ size kernel/softirq.o* text data bss dec hex filename 11554 6013 4008 21575 5447 kernel/softirq.o.new 11474 6093 4008 21575 5447 kernel/softirq.o.old Signed-off-by: Joe Perches <joe@perches.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "softirq: Add support for triggering softirq work on softirqs"Christoph Hellwig2013-11-151-22/+0
| | | | | | | | | | | | | This commit was incomplete in that code to remove items from the per-cpu lists was missing and never acquired a user in the 5 years it has been in the tree. We're going to implement what it seems to try to archive in a simpler way, and this code is in the way of doing so. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* irq: Consolidate do_softirq() arch overriden implementationsFrederic Weisbecker2013-10-011-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | All arch overriden implementations of do_softirq() share the following common code: disable irqs (to avoid races with the pending check), check if there are softirqs pending, then execute __do_softirq() on a specific stack. Consolidate the common parts such that archs only worry about the stack switch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org>
* Remove GENERIC_HARDIRQ config optionMartin Schwidefsky2013-09-131-72/+3
| | | | | | | | After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* lib: cpu_rmap: avoid flushing all workqueuesDavid Decotigny2013-01-111-5/+0
| | | | | | | | | | | | | | | | | | | | | | | In some cases, free_irq_cpu_rmap() is called while holding a lock (eg rtnl). This can lead to deadlocks, because it invokes flush_scheduled_work() which ends up waiting for whole system workqueue to flush, but some pending works might try to acquire the lock we are already holding. This commit uses reference-counting to replace irq_run_affinity_notifiers(). It also removes irq_run_affinity_notifiers() altogether. [akpm@linux-foundation.org: eliminate free_cpu_rmap, rename cpu_rmap_reclaim() to cpu_rmap_release(), propagate kref_put() retval from cpu_rmap_put()] Signed-off-by: David Decotigny <decot@googlers.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Acked-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Or Gerlitz <ogerlitz@mellanox.com> Acked-by: Amir Vadai <amirv@mellanox.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* time: RCU permitted to stop idle entry via softirqPaul E. McKenney2012-09-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The can_stop_idle_tick() function complains if a softirq vector is raised too late in the idle-entry process, presumably in order to prevent dangling softirq invocations from being delayed across the full idle period, which might be indefinitely long -- and if softirq was asserted any later than the call to this function, such a delay might well happen. However, RCU needs to be able to use softirq to stop idle entry in order to be able to drain RCU callbacks from the current CPU, which in turn enables faster entry into dyntick-idle mode, which in turn reduces power consumption. Because RCU takes this action at a well-defined point in the idle-entry path, it is safe for RCU to take this approach. This commit therefore silences the error message that is sometimes produced when the going-idle CPU suddenly finds that it has an RCU_SOFTIRQ to process. The error message will continue to be issued for other softirq vectors. Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* random: final removal of IRQF_SAMPLE_RANDOMTheodore Ts'o2012-07-191-2/+0
| | | | | | | The IRQF_SAMPLE_RANDOM flag is finally gone from the kernel tree, only three years late. :-) Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* genirq: reimplement exit_irq_thread() hook via task_work_add()Oleg Nesterov2012-05-231-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | exit_irq_thread() and task->irq_thread are needed to handle the unexpected (and unlikely) exit of irq-thread. We can use task_work instead and make this all private to kernel/irq/manage.c, cleanup plus micro-optimization. 1. rename exit_irq_thread() to irq_thread_dtor(), make it static, and move it up before irq_thread(). 2. change irq_thread() to do task_work_add(irq_thread_dtor) at the start and task_work_cancel() before return. tracehook_notify_resume() can never play with kthreads, only do_exit()->exit_task_work() can call the callback and this is what we want. 3. remove task_struct->irq_thread and the special hook in do_exit(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexander Gordeev <agordeev@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Smith <dsmith@redhat.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* genirq: Streamline irq_actionThomas Gleixner2012-04-191-4/+4
| | | | | | | | There is no need to have flags as unsigned long. Make it unsigned int and put it together with irq so it does not waste space on 64 bit. Make irq unsigned int while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Remove all #inclusions of asm/system.hDavid Howells2012-03-281-1/+0
| | | | | | | | | Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
* tracing/softirq: Move __raise_softirq_irqoff() out of headerSteven Rostedt2012-02-031-6/+1
| | | | | | | | | | | | The __raise_softirq_irqoff() contains a tracepoint. As tracepoints in headers can cause issues, and not to mention, bloats the kernel when they are in a static inline, it is best to move the function that contains the tracepoint out of the header and into softirq.c. Link: http://lkml.kernel.org/r/20120118120711.GB14863@elte.hu Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlierIan Campbell2011-10-171-0/+3
| | | | | | | | | | | | | | | | | | | | | This adds a mechanism to resume selected IRQs during syscore_resume instead of dpm_resume_noirq. Under Xen we need to resume IRQs associated with IPIs early enough that the resched IPI is unmasked and we can therefore schedule ourselves out of the stop_machine where the suspend/resume takes place. This issue was introduced by 676dc3cf5bc3 "xen: Use IRQF_FORCE_RESUME". Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com> Cc: xen-devel <xen-devel@lists.xensource.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk Cc: stable@kernel.org (at least to 2.6.32.y) Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: percpu: allow interrupt type to be set at enable timeMarc Zyngier2011-10-031-1/+1
| | | | | | | | | | | | | | | As request_percpu_irq() doesn't allow for a percpu interrupt to have its type configured (it is generally impossible to configure it on all CPUs at once), add a 'type' argument to enable_percpu_irq(). This allows some low-level, board specific init code to be switched to a generic API. [ tglx: Added WARN_ON argument ] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Abhijeet Dharmapurikar <adharmap@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Add support for per-cpu dev_id interruptsMarc Zyngier2011-10-031-11/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* atomic: use <linux/atomic.h>Arun Sharma2011-07-261-1/+1
| | | | | | | | | | | | | | This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rcu: Use softirq to address performance regressionShaohua Li2011-06-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a26ac2455ffcf3(rcu: move TREE_RCU from softirq to kthread) introduced performance regression. In an AIM7 test, this commit degraded performance by about 40%. The commit runs rcu callbacks in a kthread instead of softirq. We observed high rate of context switch which is caused by this. Out test system has 64 CPUs and HZ is 1000, so we saw more than 64k context switch per second which is caused by RCU's per-CPU kthread. A trace showed that most of the time the RCU per-CPU kthread doesn't actually handle any callbacks, but instead just does a very small amount of work handling grace periods. This means that RCU's per-CPU kthreads are making the scheduler do quite a bit of work in order to allow a very small amount of RCU-related processing to be done. Alex Shi's analysis determined that this slowdown is due to lock contention within the scheduler. Unfortunately, as Peter Zijlstra points out, the scheduler's real-time semantics require global action, which means that this contention is inherent in real-time scheduling. (Yes, perhaps someone will come up with a workaround -- otherwise, -rt is not going to do well on large SMP systems -- but this patch will work around this issue in the meantime. And "the meantime" might well be forever.) This patch therefore re-introduces softirq processing to RCU, but only for core RCU work. RCU callbacks are still executed in kthread context, so that only a small amount of RCU work runs in softirq context in the common case. This should minimize ksoftirqd execution, allowing us to skip boosting of ksoftirqd for CONFIG_RCU_BOOST=y kernels. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Tested-by: "Alex,Shi" <alex.shi@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* rcu: move TREE_RCU from softirq to kthreadPaul E. McKenney2011-05-051-1/+0
| | | | | | | | | | | | | | | | | | If RCU priority boosting is to be meaningful, callback invocation must be boosted in addition to preempted RCU readers. Otherwise, in presence of CPU real-time threads, the grace period ends, but the callbacks don't get invoked. If the callbacks don't get invoked, the associated memory doesn't get freed, so the system is still subject to OOM. But it is not reasonable to priority-boost RCU_SOFTIRQ, so this commit moves the callback invocations to a kthread, which can be boosted easily. Also add comments and properly synchronized all accesses to rcu_cpu_kthread_task, as suggested by Lai Jiangshan. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-03 20:04:34 +0000