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* genirq: Fix null pointer reference in irq_set_affinity_hint()Jesse Brandeburg2015-02-09
| | | | | | | | | | | | | | The recent set_affinity commit by me introduced some null pointer dereferences on driver unload, because some drivers call this function with a NULL argument. This fixes the issue by just checking for null before setting the affinity mask. Fixes: e2e64a932556 ("genirq: Set initial affinity in irq_set_affinity_hint()") Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> CC: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20150128185739.9689.84588.stgit@jbrandeb-cp2.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* genirq: Set initial affinity in irq_set_affinity_hint()Jesse Brandeburg2015-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Problem: The default behavior of the kernel is somewhat undesirable as all requested interrupts end up on CPU0 after registration. A user can run irqbalance daemon, or can manually configure smp_affinity via the proc filesystem, but the default affinity of the interrupts for all devices is always CPU zero, this can cause performance problems or very heavy cpu use of only one core if not noticed and fixed by the user. Solution: Enable the setting of the initial affinity directly when the driver sets a hint. This enabling means that kernel drivers can include an initial affinity setting for the interrupt, instead of all interrupts starting out life on CPU0. Of course if irqbalance is still running then the interrupts will get moved as before. This function is currently called by drivers in block, crypto, infiniband, ethernet and scsi trees, but only a handful, so these will be the devices affected by this change. Tested on i40e, and default interrupts were spread across the CPUs according to the hint. drivers/block/mtip32xx/mtip32xx.c:3 drivers/block/nvme-core.c:2 drivers/crypto/qat/qat_dh895xcc/adf_isr.c:3 drivers/infiniband/hw/qib/qib_iba7322.c:2 drivers/net/ethernet/intel/i40e/i40e_main.c:3 drivers/net/ethernet/intel/i40evf/i40evf_main.c:3 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c:3 drivers/net/ethernet/mellanox/mlx4/en_cq.c:2 drivers/scsi/hpsa.c:3 drivers/scsi/lpfc/lpfc_init.c:3 drivers/scsi/megaraid/megaraid_sas_base.c:8 drivers/soc/ti/knav_qmss_acc.c:1 drivers/soc/ti/knav_qmss_queue.c:2 drivers/virtio/virtio_pci_common.c:2 Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20141219012206.4220.27491.stgit@jbrandeb-cp2.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Add IRQ_SET_MASK_OK_DONE to support stacked irqchipJiang Liu2014-11-23
| | | | | | | | | | | | | | | | Add IRQ_SET_MASK_OK_DONE in addition to IRQ_SET_MASK_OK and IRQ_SET_MASK_OK_NOCOPY to support stacked irqchip. IRQ_SET_MASK_OK_DONE is the same as IRQ_SET_MASK_OK to irq core. To stacked irqchip, it means that ascendant irqchips have done all the work and no more handling needed in descendant irqchips. 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>
* genirq: Add sanity checks for PM options on shared interrupt linesThomas Gleixner2014-09-01
| | | | | | | | Account the IRQF_NO_SUSPEND and IRQF_RESUME_EARLY actions on shared interrupt lines and yell loudly if there is a mismatch. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* genirq: Move suspend/resume logic into irq/pm codeThomas Gleixner2014-09-01
| | | | | | | | No functional change. Preparatory patch for cleaning up the suspend abort functionality. Update the comments while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* genirq: Sanitize spurious interrupt detection of threaded irqsThomas Gleixner2014-05-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Till reported that the spurious interrupt detection of threaded interrupts is broken in two ways: - note_interrupt() is called for each action thread of a shared interrupt line. That's wrong as we are only interested whether none of the device drivers felt responsible for the interrupt, but by calling multiple times for a single interrupt line we account IRQ_NONE even if one of the drivers felt responsible. - note_interrupt() when called from the thread handler is not serialized. That leaves the members of irq_desc which are used for the spurious detection unprotected. To solve this we need to defer the spurious detection of a threaded interrupt to the next hardware interrupt context where we have implicit serialization. If note_interrupt is called with action_ret == IRQ_WAKE_THREAD, we check whether the previous interrupt requested a deferred check. If not, we request a deferred check for the next hardware interrupt and return. If set, we check whether one of the interrupt threads signaled success. Depending on this information we feed the result into the spurious detector. If one primary handler of a shared interrupt returns IRQ_HANDLED we disable the deferred check of irq threads on the same line, as we have found at least one device driver who cared. Reported-by: Till Straumann <strauman@slac.stanford.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Austin Schuh <austin@peloton-tech.com> Cc: Oliver Hartkopp <socketcan@hartkopp.net> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: Pavel Pisa <pisa@cmp.felk.cvut.cz> Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: linux-can@vger.kernel.org Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1303071450130.22263@ionos
* genirq: Allow forcing cpu affinity of interruptsThomas Gleixner2014-04-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Add a new IRQCHIP_EOI_THREADED flagThomas Gleixner2014-03-14
| | | | | | | | | | | | | | | | | | | | | The flag is necessary for interrupt chips which require an ACK/EOI after the handler has run. In case of threaded handlers this needs to happen after the threaded handler has completed before the unmask of the interrupt. The flag is only unseful in combination with the handle_fasteoi_irq flow control handler. It can be combined with the flag IRQCHIP_EOI_IF_HANDLED, so the EOI is not issued when the interrupt is disabled or in progress. Tested-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-sunxi@googlegroups.com Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Link: http://lkml.kernel.org/r/1394733834-26839-2-git-send-email-hdegoede@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'irq/for-gpio' into irq/coreThomas Gleixner2014-03-12
|\ | | | | | | | | | | | | Merge the request/release callbacks which are in a separate branch for consumption by the gpio folks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq: Provide irq_request/release_resources chip callbacksThomas Gleixner2014-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For certain irq types, e.g. gpios, it's necessary to request resources before starting up the irq. This might fail so we cannot use the irq_startup() callback because we might call the irq_set_type() callback before that which does not make sense when the resource is not available. Calling irq_startup() before irq_set_type() can lead to spurious interrupts which is not desired either. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jean-Jacques Hiblot <jjhiblot@traphandler.com> Cc: Grant Likely <grant.likely@linaro.org> Cc: linux-arm-kernel@lists.infradead.org Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1403080857160.18573@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq: Remove racy waitqueue_active checkChuansheng Liu2014-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We hit one rare case below: T1 calling disable_irq(), but hanging at synchronize_irq() always; The corresponding irq thread is in sleeping state; And all CPUs are in idle state; After analysis, we found there is one possible scenerio which causes T1 is waiting there forever: CPU0 CPU1 synchronize_irq() wait_event() spin_lock() atomic_dec_and_test(&threads_active) insert the __wait into queue spin_unlock() if(waitqueue_active) atomic_read(&threads_active) wake_up() Here after inserted the __wait into queue on CPU0, and before test if queue is empty on CPU1, there is no barrier, it maybe cause it is not visible for CPU1 immediately, although CPU0 has updated the queue list. It is similar for CPU0 atomic_read() threads_active also. So we'd need one smp_mb() before waitqueue_active.that, but removing the waitqueue_active() check solves it as wel l and it makes things simple and clear. Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> Cc: Xiaoming Wang <xiaoming.wang@intel.com> Link: http://lkml.kernel.org/r/1393212590-32543-1-git-send-email-chuansheng.liu@intel.com Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Update the a comment typoChuansheng Liu2014-02-19
| | | | | | | | | | | | | | | | Change the comment "chasnge" to "change". Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com> Link: http://lkml.kernel.org/r/1392020037-5484-2-git-send-email-chuansheng.liu@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Provide irq_wake_thread()Thomas Gleixner2014-02-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Provide synchronize_hardirq()Thomas Gleixner2014-02-19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | synchronize_irq() waits for hard irq and threaded handlers to complete before returning. For some special cases we only need to make sure that the hard interrupt part of the irq line is not in progress when we disabled the - possibly shared - interrupt at the device level. A proper use case for this was provided by Russell. The sdhci driver requires some irq triggered functions to be run in thread context. The current implementation of the thread context is a sdio private kthread construct, which has quite some shortcomings. These can be avoided when the thread is directly associated to the device interrupt via the generic threaded irq infrastructure. Though there is a corner case related to run time power management where one side disables the device interrupts at the device level and needs to make sure, that an already running hard interrupt handler has completed before proceeding further. Though that hard interrupt handler might wake the associated thread, which in turn can request the runtime PM to reenable the device. Using synchronize_irq() leads to an immediate deadlock of the irq thread waiting for the PM lock and the synchronize_irq() waiting for the irq thread to complete. Due to the fact that it is sufficient for this case to ensure that no hard irq handler is executing a new function which avoids the check for the thread is required. Add a function, which just monitors the hard irq parts and ignores the threaded handlers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: 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/20140215003823.653236081@linutronix.de
* Merge branch 'for-linus' of ↵Linus Torvalds2013-11-15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "Usual earth-shaking, news-breaking, rocket science pile from trivial.git" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits) doc: usb: Fix typo in Documentation/usb/gadget_configs.txt doc: add missing files to timers/00-INDEX timekeeping: Fix some trivial typos in comments mm: Fix some trivial typos in comments irq: Fix some trivial typos in comments NUMA: fix typos in Kconfig help text mm: update 00-INDEX doc: Documentation/DMA-attributes.txt fix typo DRM: comment: `halve' -> `half' Docs: Kconfig: `devlopers' -> `developers' doc: typo on word accounting in kprobes.c in mutliple architectures treewide: fix "usefull" typo treewide: fix "distingush" typo mm/Kconfig: Grammar s/an/a/ kexec: Typo s/the/then/ Documentation/kvm: Update cpuid documentation for steal time and pv eoi treewide: Fix common typo in "identify" __page_to_pfn: Fix typo in comment Correct some typos for word frequency clk: fixed-factor: Fix a trivial typo ...
| * irq: Fix some trivial typos in commentsXie XiuQi2013-10-18
| | | | | | | | | | | | Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com> [jkosina@suse.cz: fix 'explicitly', noticed by Randy Dunlap] Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | genirq: Set the irq thread policy without checking CAP_SYS_NICEThomas Pfaff2013-10-28
|/ | | | | | | | | | | | | | | | | | | | | | In commit ee23871389 ("genirq: Set irq thread to RT priority on creation") we moved the assigment of the thread's priority from the thread's function into __setup_irq(). That function may run in user context for instance if the user opens an UART node and then driver calls requests in the ->open() callback. That user may not have CAP_SYS_NICE and so the irq thread won't run with the SCHED_OTHER policy. This patch uses sched_setscheduler_nocheck() so we omit the CAP_SYS_NICE check which is otherwise required for the SCHED_OTHER policy. [bigeasy: Rewrite the changelog] Signed-off-by: Thomas Pfaff <tpfaff@pcs.com> Cc: Ivo Sieben <meltedpianoman@gmail.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1381489240-29626-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Fix can_request_irq() for IRQs without an actionBen Hutchings2013-06-28
| | | | | | | | | | | | | | | | | | Commit 02725e7471b8 ('genirq: Use irq_get/put functions'), inadvertently changed can_request_irq() to return 0 for IRQs that have no action. This causes pcibios_lookup_irq() to select only IRQs that already have an action with IRQF_SHARED set, or to fail if there are none. Change can_request_irq() to return 1 for IRQs that have no action (if the first two conditions are met). Reported-by: Bjarni Ingi Gislason <bjarniig@rhi.hi.is> Tested-by: Bjarni Ingi Gislason <bjarniig@rhi.hi.is> (against 3.2) Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: 709647@bugs.debian.org Cc: stable@vger.kernel.org # 2.6.39+ Link: http://bugs.debian.org/709647 Link: http://lkml.kernel.org/r/1372383630.23847.40.camel@deadeye.wl.decadent.org.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Set irq thread to RT priority on creationIvo Sieben2013-06-11
| | | | | | | | | | | | | | | | | | When a threaded irq handler is installed the irq thread is initially created on normal scheduling priority. Only after the irq thread is woken up it sets its priority to RT_FIFO MAX_USER_RT_PRIO/2 itself. This means that interrupts that occur directly after the irq handler is installed will be handled on a normal scheduling priority instead of the realtime priority that one would expect. Fix this by setting the RT priority on creation of the irq_thread. Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1370254322-17240-1-git-send-email-meltedpianoman@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2013-02-19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes from Ingo Molnar: "Main changes: - scheduler side full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker. - Initial sched.h split-up changes, by Clark Williams - select_idle_sibling() performance improvement by Mike Galbraith: " 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs " - sched_rr_get_interval() ABI fix/change. We think this detail is not used by apps (so it's not an ABI in practice), but lets keep it under observation. - misc RT scheduling cleanups, optimizations" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h> cputime: Remove irqsave from seqlock readers sched, powerpc: Fix sched.h split-up build failure cputime: Restore CPU_ACCOUNTING config defaults for PPC64 sched/rt: Move rt specific bits into new header file sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice sched: Move sched.h sysctl bits into separate header sched: Fix signedness bug in yield_to() sched: Fix select_idle_sibling() bouncing cow syndrome sched/rt: Further simplify pick_rt_task() sched/rt: Do not account zero delta_exec in update_curr_rt() cputime: Safely read cputime of full dynticks CPUs kvm: Prepare to add generic guest entry/exit callbacks cputime: Use accessors to read task cputime stats cputime: Allow dynamic switch between tick/virtual based cputime accounting cputime: Generic on-demand virtual cputime accounting cputime: Move default nsecs_to_cputime() to jiffies based cputime file cputime: Librarize per nsecs resolution cputime definitions cputime: Avoid multiplication overflow on utime scaling context_tracking: Export context state for generic vtime ... Fix up conflict in kernel/context_tracking.c due to comment additions.
| * sched/rt: Move rt specific bits into new header fileClark Williams2013-02-07
| | | | | | | | | | | | | | | | | | | | | | Move rt scheduler definitions out of include/linux/sched.h into new file include/linux/sched/rt.h Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | genirq: Export enable/disable_percpu_irq()Chris Metcalf2013-02-18
|/ | | | | | | | | These functions are used by the tilegx onchip network driver, and it's useful to be able to load that driver as a module. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Link: http://lkml.kernel.org/r/201302012043.r11KhNZF024371@farm-0021.internal.tilera.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* irq: tsk->comm is an arrayAlan Cox2012-12-18
| | | | | | | | | | The array check is useless so remove it. [akpm@linux-foundation.org: remove comment, per David] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* genirq: Always force thread affinityThomas Gleixner2012-11-12
| | | | | | | | | | | | | | | | | | | | | | | | Sankara reported that the genirq core code fails to adjust the affinity of an interrupt thread in several cases: 1) On request/setup_irq() the call to setup_affinity() happens before the new action is registered, so the new thread is not notified. 2) For secondary shared interrupts nothing notifies the new thread to change its affinity. 3) Interrupts which have the IRQ_NO_BALANCE flag set are not moving the thread either. Fix this by setting the thread affinity flag right on thread creation time. This ensures that under all circumstances the thread moves to the right place. Requires a check in irq_thread_check_affinity for an existing affinity mask (CONFIG_CPU_MASK_OFFSTACK=y) Reported-and-tested-by: Sankara Muthukrishnan <sankara.m@gmail.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1209041738200.2754@ionos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* irq: Set CPU affinity right on thread creationSankara Muthukrishnan2012-11-01
| | | | | | | | | | | | | | | | As irq_thread_check_affinity is called ONLY inside the while loop in the irq thread, the core affinity is set only when an interrupt occurs. This patch sets the core affinity right after the irq thread is created and before it waits for interrupts. In real-tiime targets that do not typically change the core affinity of irqs during run-time, this patch will save additional latency of an irq thread in setting the core affinity during the first interrupt occurrence for that irq. Signed-off-by: Sankara S Muthukrishnan <sankara.m@ni.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/CAFQPvXeVZ858WFYimEU5uvLNxLDd6bJMmqWihFmbCf3ntokz0A@mail.gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Provide means to retrigger parentThomas Gleixner2012-11-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | Attempts to retrigger nested threaded IRQs currently fail because they have no primary handler. In order to support retrigger of nested IRQs, the parent IRQ needs to be retriggered. To fix, when an IRQ needs to be resent, if the interrupt has a parent IRQ and runs in the context of the parent IRQ, then resend the parent. Also, handle_nested_irq() needs to clear the replay flag like the other handlers, otherwise check_irq_resend() will set it and it will never be cleared. Without clearing, it results in the first resend working fine, but check_irq_resend() returning early on subsequent resends because the replay flag is still set. Problem discovered on ARM/OMAP platforms where a nested IRQ that's also a wakeup IRQ happens late in suspend and needed to be retriggered during the resume process. [khilman@ti.com: changelog edits, clear IRQS_REPLAY in handle_nested_irq()] Reported-by: Kevin Hilman <khilman@ti.com> Tested-by: Kevin Hilman <khilman@ti.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1350425269-11489-1-git-send-email-khilman@deeprootsystems.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2012-08-03
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Ingo Molnar. * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Allow irq chips to mark themself oneshot safe
| * genirq: Allow irq chips to mark themself oneshot safeThomas Gleixner2012-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Some interrupt chips like MSI are oneshot safe by implementation. For those interrupts we can avoid the mask/unmask sequence for threaded interrupt handlers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1207132056540.32033@ionos Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Jan Kiszka <jan.kiszka@web.de>
* | Merge tag 'random_for_linus' of ↵Linus Torvalds2012-07-31
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull random subsystem patches from Ted Ts'o: "This patch series contains a major revamp of how we collect entropy from interrupts for /dev/random and /dev/urandom. The goal is to addresses weaknesses discussed in the paper "Mining your Ps and Qs: Detection of Widespread Weak Keys in Network Devices", by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman, which will be published in the Proceedings of the 21st Usenix Security Symposium, August 2012. (See https://factorable.net for more information and an extended version of the paper.)" Fix up trivial conflicts due to nearby changes in drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c} * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits) random: mix in architectural randomness in extract_buf() dmi: Feed DMI table to /dev/random driver random: Add comment to random_initialize() random: final removal of IRQF_SAMPLE_RANDOM um: remove IRQF_SAMPLE_RANDOM which is now a no-op sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op [ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op ...
| * | random: remove rand_initialize_irq()Theodore Ts'o2012-07-19
| |/ | | | | | | | | | | | | | | | | | | | | | | With the new interrupt sampling system, we are no longer using the timer_rand_state structure in the irq descriptor, so we can stop initializing it now. [ Merged in fixes from Sedat to find some last missing references to rand_initialize_irq() ] Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
* | merge task_work and rcu_head, get rid of separate allocation for keyring caseAl Viro2012-07-22
| | | | | | | | | | | | | | | | task_work and rcu_head are identical now; merge them (calling the result struct callback_head, rcu_head #define'd to it), kill separate allocation in security/keys since we can just use cred->rcu now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | trimming task_work: kill ->dataAl Viro2012-07-22
|/ | | | | | | | get rid of the only user of ->data; this is _not_ the final variant - in the end we'll have task_work and rcu_head identical and just use cred->rcu, at which point the separate allocation will be gone completely. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
*-. Merge branches 'irq-urgent-for-linus' and 'smp-hotplug-for-linus' of ↵Linus Torvalds2012-06-04
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq and smpboot updates from Thomas Gleixner: "Just cleanup patches with no functional change and a fix for suspend issues." * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Introduce irq_do_set_affinity() to reduce duplicated code genirq: Add IRQS_PENDING for nested and simple irq * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smpboot, idle: Fix comment mismatch over idle_threads_init() smpboot, idle: Optimize calls to smp_processor_id() in idle_threads_init()
| * | genirq: Introduce irq_do_set_affinity() to reduce duplicated codeJiang Liu2012-05-24
| |/ | | | | | | | | | | | | | | | | | | | | | | | | All invocations of chip->irq_set_affinity() are doing the same return value checks. Let them all use a common function. [ tglx: removed the silly likely while at it ] Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Keping Chen <chenkeping@huawei.com> Link: http://lkml.kernel.org/r/1333120296-13563-3-git-send-email-jiang.liu@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-31
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull second pile of signal handling patches from Al Viro: "This one is just task_work_add() series + remaining prereqs for it. There probably will be another pull request from that tree this cycle - at least for helpers, to get them out of the way for per-arch fixes remaining in the tree." Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile had brought in commit 97fd75b7b8e0 ("kernel/irq/manage.c: use the pr_foo() infrastructure to prefix printks") which changed one of the pr_err() calls that this merge moves around. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: keys: kill task_struct->replacement_session_keyring keys: kill the dummy key_replace_session_keyring() keys: change keyctl_session_to_parent() to use task_work_add() genirq: reimplement exit_irq_thread() hook via task_work_add() task_work_add: generic process-context callbacks avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers parisc: need to check NOTIFY_RESUME when exiting from syscall move key_repace_session_keyring() into tracehook_notify_resume() TIF_NOTIFY_RESUME is defined on all targets now
| * | genirq: reimplement exit_irq_thread() hook via task_work_add()Oleg Nesterov2012-05-23
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* / kernel/irq/manage.c: use the pr_foo() infrastructure to prefix printksAndrew Morton2012-05-31
|/ | | | | | | | | Use the module-wide pr_fmt() mechanism rather than open-coding "genirq: " everywhere. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/umlLinus Torvalds2012-05-23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull UML updates from Richard Weinberger: "Most changes are bug fixes and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: missing checks of __put_user()/__get_user() return values um: stub_rt_sigsuspend isn't needed these days anymore um/x86: merge (and trim) 32- and 64-bit variants of ptrace.h irq: Remove irq_chip->release() um: Remove CONFIG_IRQ_RELEASE_METHOD um: Remove usage of irq_chip->release() um: Implement um_free_irq() um: Fix __swp_type() um: Implement a custom pte_same() function um: Add BUG() to do_ops()'s error path um: Remove unused variables um: bury unused _TIF_RESTORE_SIGMASK um: wrong sigmask saved in case of multiple sigframes um: add TIF_NOTIFY_RESUME um: ->restart_block.fn needs to be reset on sigreturn
| * irq: Remove irq_chip->release()Richard Weinberger2012-05-21
| | | | | | | | | | | | | | | | As it's only user (UML) does no longer need it we can get rid of it. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Be more informative on irq type mismatchThomas Gleixner2012-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | We require that shared interrupts agree on a few flag settings. Right now we silently return with an error code without giving any hint why we reject it. Make the printout unconditionally and actually useful by printing the flags of the new and the already registered action. Convert all printks to pr_* and use a proper prefix while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Reject bogus threaded irq requestsThomas Gleixner2012-04-19
|/ | | | | | | | | | | | | | | | | | | Requesting a threaded interrupt without a primary handler and without IRQF_ONESHOT set is dangerous. The core will use the default primary handler for it, which merily wakes the thread. For a level type interrupt this results in an interrupt storm, because the interrupt line is reenabled after the primary handler runs. The device has still the line asserted, which brings us back into the primary handler. While this works for edge type interrupts, we play it safe and reject unconditionally because we can't say for sure which type this interrupt really has. The type flags are unreliable as the underlying chip implementation can override them. And we cannot assume that developers using that interface know what they are doing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Respect NUMA node affinity in setup_irq_irq affinity()Prarit Bhargava2012-03-29
| | | | | | | | | | | | | | | | | | We respect node affinity of devices already in the irq descriptor allocation, but we ignore it for the initial interrupt affinity setup, so the interrupt might be routed to a different node. Restrict the default affinity mask to the node on which the irq descriptor is allocated. [ tglx: Massaged changelog ] Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: David Rientjes <rientjes@google.com> Link: http://lkml.kernel.org/r/1332788538-17425-1-git-send-email-prarit@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Get rid of unneeded force parameter in irq_finalize_oneshot()Alexander Gordeev2012-03-29
| | | | | | | | | | | | | The only place irq_finalize_oneshot() is called with force parameter set is the threaded handler error exit path. But IRQTF_RUNTHREAD is dropped at this point and irq_wake_thread() is not going to set it again, since PF_EXITING is set for this thread already. So irq_finalize_oneshot() will drop the threads bit in threads_oneshot anyway and hence the force parameter is superfluous. Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120321162234.GP24806@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Remove paranoid warnons and bogus fixupsThomas Gleixner2012-03-16
| | | | | | | | | | | | | | | | | | | | | | | | | Alexander pointed out that the warnons in the regular exit path are bogus and the thread_mask one actually could be triggered when __setup_irq() hands out that thread_mask again after __free_irq() dropped irq_desc->lock. Thinking more about it, neither IRQTF_RUNTHREAD nor the bit in thread_mask can be set as this is the regular exit path. We come here due to: __free_irq() remove action from desc synchronize_irq() kthread_stop() So synchronize_irq() makes sure that the thread finished running and cleaned up both the thread_active count and thread_mask. After that point nothing can set IRQTF_RUNTHREAD on this action. So the warnons and the cleanups are pointless. Reported-by: Alexander Gordeev <agordeev@redhat.com> Cc: Ido Yariv <ido@wizery.com> Link: http://lkml.kernel.org/r/20120315190755.GA6732@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* genirq: Flush the irq thread on synchronizationIdo Yariv2012-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current implementation does not always flush the threaded handler when disabling the irq. In case the irq handler was called, but the threaded handler hasn't started running yet, the interrupt will be flagged as pending, and the handler will not run. This implementation has some issues: First, if the interrupt is a wake source and flagged as pending, the system will not be able to suspend. Second, when quickly disabling and re-enabling the irq, the threaded handler might continue to run after the irq is re-enabled without the irq handler being called first. This might be an unexpected behavior. In addition, it might be counter-intuitive that the threaded handler will not be called even though the irq handler was called and returned IRQ_WAKE_THREAD. Fix this by always waiting for the threaded handler to complete in synchronize_irq(). [ tglx: Massaged comments, added WARN_ONs and the missing IRQTF_RUNTHREAD check in exit_irq_thread() ] Signed-off-by: Ido Yariv <ido@wizery.com> Link: http://lkml.kernel.org/r/1322843052-7166-1-git-send-email-ido@wizery.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* Merge branch 'linus' into irq/coreThomas Gleixner2012-03-13
|\ | | | | | | | | | | Reason: Get upstream fixes integrated before further modifications. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq: Clear action->thread_mask if IRQ_ONESHOT is not setThomas Gleixner2012-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Xommit ac5637611(genirq: Unmask oneshot irqs when thread was not woken) fails to unmask when a !IRQ_ONESHOT threaded handler is handled by handle_level_irq. This happens because thread_mask is or'ed unconditionally in irq_wake_thread(), but for !IRQ_ONESHOT interrupts never cleared. So the check for !desc->thread_active fails and keeps the interrupt disabled. Keep the thread_mask zero for !IRQ_ONESHOT interrupts. Document the thread_mask magic while at it. Reported-and-tested-by: Sven Joachim <svenjoac@gmx.de> Reported-and-tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * genirq: Handle pending irqs in irq_startup()Thomas Gleixner2012-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | An interrupt might be pending when irq_startup() is called, but the startup code does not invoke the resend logic. In some cases this prevents the device from issuing another interrupt which renders the device non functional. Call the resend function in irq_startup() to keep things going. Reported-and-tested-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: Get rid of unnecessary IRQTF_DIED flagAlexander Gordeev2012-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently IRQTF_DIED flag is set when a IRQ thread handler calls do_exit() But also PF_EXITING per process flag gets set when a thread exits. This fix eliminates the duplicate by using PF_EXITING flag. Also, there is a race condition in exit_irq_thread(). In case a thread's bit is cleared in desc->threads_oneshot (and the IRQ line gets unmasked), but before IRQTF_DIED flag is set, a new interrupt might come in and set just cleared bit again, this time forever. This fix throws IRQTF_DIED flag away, eliminating the race as a result. [ tglx: Test THREAD_EXITING first as suggested by Oleg ] Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120309135958.GD2114@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | genirq: No need to check IRQTF_DIED before stopping a thread handlerAlexander Gordeev2012-03-09
| | | | | | | | | | | | | | | | | | | | | | Since 63706172f332fd3f6e7458ebfb35fa6de9c21dc5 kthread_stop() is not afraid of dead kernel threads. So no need to check if a thread is alive before stopping it. These checks still were racy. Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Link: http://lkml.kernel.org/r/20120309135939.GC2114@dhcp-26-207.brq.redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>