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2010-06-09genirq: Deal with desc->set_type() changing desc->chipThomas Gleixner1-0/+3
The set_type() function can change the chip implementation when the trigger mode changes. That might result in using an non-initialized irq chip when called from __setup_irq() or when called via set_irq_type() on an already enabled irq. The set_irq_type() function should not be called on an enabled irq, but because we forgot to put a check into it, we have a bunch of users which grew the habit of doing that and it never blew up as the function is serialized via desc->lock against all users of desc->chip and they never hit the non-initialized irq chip issue. The easy fix for the __setup_irq() issue would be to move the irq_chip_set_defaults(desc->chip) call after the trigger setting to make sure that a chip change is covered. But as we have already users, which do the type setting after request_irq(), the safe fix for now is to call irq_chip_set_defaults() from __irq_set_trigger() when desc->set_type() changed the irq chip. It needs a deeper analysis whether we should refuse to change the chip on an already enabled irq, but that'd be a large scale change to fix all the existing users. So that's neither stable nor 2.6.35 material. Reported-by: Esben Haabendal <eha@doredevelopment.dk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linuxppc-dev <linuxppc-dev@ozlabs.org> Cc: stable@kernel.org
2010-05-03genirq: Add CPU mask affinity hintPeter P Waskiewicz Jr1-0/+22
This patch adds a cpumask affinity hint to the irq_desc structure, along with a registration function and a read-only proc entry for each interrupt. This affinity_hint handle for each interrupt can be used by underlying drivers that need a better mechanism to control interrupt affinity. The underlying driver can register a cpumask for the interrupt, which will allow the driver to provide the CPU mask for the interrupt to anything that requests it. The intent is to extend the userspace daemon, irqbalance, to help hint to it a preferred CPU mask to balance the interrupt into. [ tglx: Fixed compile warnings, added WARN_ON, made SMP only ] Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com> Cc: davem@davemloft.net Cc: arjan@linux.jf.intel.com Cc: bhutchings@solarflare.com LKML-Reference: <20100430214445.3992.41647.stgit@ppwaskie-hc2.jf.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-04-13genirq: Remove IRQF_DISABLED from core codeThomas Gleixner1-30/+0
Remove all code which is related to IRQF_DISABLED from the core kernel code. IRQF_DISABLED still exists as a flag, but becomes a NOOP and will be removed after a grace period. That way we can easily revert to the previous behaviour by just restoring the core code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Miller <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@osdl.org> LKML-Reference: <20100326000405.991244690@linutronix.de>
2010-04-13genirq: Introduce request_any_context_irq()Marc Zyngier1-0/+37
Now that we enjoy threaded interrupts, we're starting to see irq_chip implementations (wm831x, pca953x) that make use of threaded interrupts for the controller, and nested interrupts for the client interrupt. It all works very well, with one drawback: Drivers requesting an IRQ must now know whether the handler will run in a thread context or not, and call request_threaded_irq() or request_irq() accordingly. The problem is that the requesting driver sometimes doesn't know about the nature of the interrupt, specially when the interrupt controller is a discrete chip (typically a GPIO expander connected over I2C) that can be connected to a wide variety of otherwise perfectly supported hardware. This patch introduces the request_any_context_irq() function that mostly mimics the usual request_irq(), except that it checks whether the irq level is configured as nested or not, and calls the right backend. On success, it also returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED. [ tglx: Made return value an enum, simplified code and made the export of request_any_context_irq GPL ] Signed-off-by: Marc Zyngier <maz@misterjones.org> Cc: <joachim.eastwood@jotron.com> LKML-Reference: <927ea285bd0c68934ddae1a47e44a9ba@localhost> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-31genirq: Force MSI irq handlers to run with interrupts disabledThomas Gleixner1-0/+10
Network folks reported that directing all MSI-X vectors of their multi queue NICs to a single core can cause interrupt stack overflows when enough interrupts fire at the same time. This is caused by the fact that we run interrupt handlers by default with interrupts enabled unless the driver reuqests the interrupt with the IRQF_DISABLED set. The NIC handlers do not set this flag, so simultaneous interrupts can nest unlimited and cause the stack overflow. The only safe counter measure is to run the interrupt handlers with interrupts disabled. We can't switch to this mode in general right now, but it is safe to do so for MSI interrupts. Force IRQF_DISABLED for MSI interrupt handlers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Linus Torvalds <torvalds@osdl.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: stable@kernel.org
2010-03-24genirq: Protect access to irq_desc->action in can_request_irq()Thomas Gleixner1-0/+4
can_request_irq() accesses and dereferences irq_desc->action w/o holding irq_desc->lock. So action can be freed on another CPU before it's dereferenced. Unlikely, but ... Protect it with desc->lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-03-10genirq: Prevent oneshot irq thread raceThomas Gleixner1-0/+18
Lars-Peter pointed out that the oneshot threaded interrupt handler code has the following race: CPU0 CPU1 hande_level_irq(irq X) mask_ack_irq(irq X) handle_IRQ_event(irq X) wake_up(thread_handler) thread handler(irq X) runs finalize_oneshot(irq X) does not unmask due to !(desc->status & IRQ_MASKED) return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This leaves the interrupt line masked forever. The reason for this is the inconsistent handling of the IRQ_MASKED flag. Instead of setting it in the mask function the oneshot support sets the flag after waking up the irq thread. The solution for this is to set/clear the IRQ_MASKED status whenever we mask/unmask an interrupt line. That's the easy part, but that cleanup opens another race: CPU0 CPU1 hande_level_irq(irq) mask_ack_irq(irq) handle_IRQ_event(irq) wake_up(thread_handler) thread handler(irq) runs finalize_oneshot_irq(irq) unmask(irq) irq triggers again handle_level_irq(irq) mask_ack_irq(irq) return from irq due to IRQ_INPROGRESS return from irq does not unmask due to (desc->status & IRQ_ONESHOT) This requires that we synchronize finalize_oneshot_irq() with the primary handler. If IRQ_INPROGESS is set we wait until the primary handler on the other CPU has returned before unmasking the interrupt line again. We probably have never seen that problem because it does not happen on UP and on SMP the irqbalancer protects us by pinning the primary handler and the thread to the same CPU. Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
2009-12-14genirq: Convert irq_desc.lock to raw_spinlockThomas Gleixner1-25/+25
Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-12-08Merge branches 'timers-for-linus-ntp' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-1/+1
* 'timers-for-linus-ntp' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ntp: Provide compability defines (You say MOD_NANO, I say ADJ_NANO) * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: do not execute DEBUG_SHIRQ when irq setup failed
2009-09-11Merge branch 'irq-threaded-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-8/+94
* 'irq-threaded-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Do not mask oneshot edge type interrupts genirq: Support nested threaded irq handling genirq: Add buslock support genirq: Add oneshot support
2009-08-18genirq: Wake up irq thread after action has been installedThomas Gleixner1-2/+8
The wake_up_process() of the new irq thread in __setup_irq() is too early as the irqaction is not yet fully initialized especially action->irq is not yet set. The interrupt thread might dereference the wrong irq descriptor. Move the wakeup after the action is installed and action->irq has been set. Reported-by: Michael Buesch <mb@bu3sch.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Buesch <mb@bu3sch.de>
2009-08-17genirq: Support nested threaded irq handlingThomas Gleixner1-3/+31
Interrupt chips which are behind a slow bus (i2c, spi ...) and demultiplex other interrupt sources need to run their interrupt handler in a thread. The demultiplexed interrupt handlers need to run in thread context as well and need to finish before the demux handler thread can reenable the interrupt line. So the easiest way is to run the sub device handlers in the context of the demultiplexing handler thread. To avoid that a separate thread is created for the subdevices the function set_nested_irq_thread() is provided which sets the IRQ_NESTED_THREAD flag in the interrupt descriptor. A driver which calls request_threaded_irq() must not be aware of the fact that the threaded handler is called in the context of the demultiplexing handler thread. The setup code checks the IRQ_NESTED_THREAD flag which was set from the irq chip setup code and does not setup a separate thread for the interrupt. The primary function which is provided by the device driver is replaced by an internal dummy function which warns when it is called. For the demultiplexing handler a helper function handle_nested_irq() is provided which calls the demux interrupt thread function in the context of the caller and does the proper interrupt accounting and takes the interrupt disabled status of the demultiplexed subdevice into account. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-17genirq: Add buslock supportThomas Gleixner1-1/+18
Some interrupt chips are connected to a "slow" bus (i2c, spi ...). The bus access needs to sleep and therefor cannot be called in atomic contexts. Some of the generic interrupt management functions like disable_irq(), enable_irq() ... call interrupt chip functions with the irq_desc->lock held and interrupts disabled. This does not work for such devices. Provide a separate synchronization mechanism for such interrupt chips. The irq_chip structure is extended by two optional functions (bus_lock and bus_sync_and_unlock). The idea is to serialize the bus access for those operations in the core code so that drivers which are behind that bus operated interrupt controller do not have to worry about it and just can use the normal interfaces. To achieve this we add two function pointers to the irq_chip: bus_lock and bus_sync_unlock. bus_lock() is called to serialize access to the interrupt controller bus. Now the core code can issue chip->mask/unmask ... commands without changing the fast path code at all. The chip implementation merily stores that information in a chip private data structure and returns. No bus interaction as these functions are called from atomic context. After that bus_sync_unlock() is called outside the atomic context. Now the chip implementation issues the bus commands, waits for completion and unlocks the interrupt controller bus. The irq_chip implementation as pseudo code: struct irq_chip_data { struct mutex mutex; unsigned int irq_offset; unsigned long mask; unsigned long mask_status; } static void bus_lock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); mutex_lock(&data->mutex); } static void mask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask |= (1 << irq); } static void unmask(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); irq -= data->irq_offset; data->mask &= ~(1 << irq); } static void bus_sync_unlock(unsigned int irq) { struct irq_chip_data *data = get_irq_desc_chip_data(irq); if (data->mask != data->mask_status) { do_bus_magic_to_set_mask(data->mask); data->mask_status = data->mask; } mutex_unlock(&data->mutex); } The device drivers can use request_threaded_irq, free_irq, disable_irq and enable_irq as usual with the only restriction that the calls need to come from non atomic context. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-17genirq: Add oneshot supportThomas Gleixner1-4/+45
For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
2009-08-13genirq: prevent wakeup of freed irq threadLinus Torvalds1-10/+7
free_irq() can remove an irqaction while the corresponding interrupt is in progress, but free_irq() sets action->thread to NULL unconditionally, which might lead to a NULL pointer dereference in handle_IRQ_event() when the hard interrupt context tries to wake up the handler thread. Prevent this by moving the thread stop after synchronize_irq(). No need to set action->thread to NULL either as action is going to be freed anyway. This fixes a boot crash reported against preempt-rt which uses the mainline irq threads code to implement full irq threading. [ tglx: removed local irqthread variable ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-22genirq: Fix UP compile failure caused by irq_thread_check_affinityBruno Premont1-0/+5
Since genirq: Delegate irq affinity setting to the irq thread (591d2fb02ea80472d846c0b8507007806bdd69cc) compilation with CONFIG_SMP=n fails with following error: /usr/src/linux-2.6/kernel/irq/manage.c: In function 'irq_thread_check_affinity': /usr/src/linux-2.6/kernel/irq/manage.c:475: error: 'struct irq_desc' has no member named 'affinity' make[4]: *** [kernel/irq/manage.o] Error 1 That commit adds a new function irq_thread_check_affinity() which uses struct irq_desc.affinity which is only available for CONFIG_SMP=y. Move that function under #ifdef CONFIG_SMP. [ tglx@brownpaperbag: compile and boot tested on UP and SMP ] Signed-off-by: Bruno Premont <bonbons@linux-vserver.org> LKML-Reference: <20090722222232.2eb3e1c4@neptune.home> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-07-21genirq: Delegate irq affinity setting to the irq threadThomas Gleixner1-6/+44
irq_set_thread_affinity() calls set_cpus_allowed_ptr() which might sleep, but irq_set_thread_affinity() is called with desc->lock held and can be called from hard interrupt context as well. The code has another bug as it does not hold a ref on the task struct as required by set_cpus_allowed_ptr(). Just set the IRQTF_AFFINITY bit in action->thread_flags. The next time the thread runs it migrates itself. Solves all of the above problems nicely. Add kerneldoc to irq_set_thread_affinity() while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission>
2009-06-20Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-1/+1
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq, irq.h: Fix kernel-doc warnings genirq: fix comment to say IRQ_WAKE_THREAD
2009-05-12genirq: fix comment to say IRQ_WAKE_THREADSteven Rostedt1-1/+1
Trying to implement a driver to use threaded irqs, I was confused when the return value to use that was described in the comment above request_threaded_irq was not defined. Turns out that the enum is IRQ_WAKE_THREAD where as the comment said IRQ_THREAD_WAKE. [Impact: do not confuse developers with wrong comments ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <alpine.DEB.2.00.0905121431020.13338@gandalf.stny.rr.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-04-28irq: only update affinity if ->set_affinity() is sucessfullYinghai Lu1-6/+11
irq_set_affinity() and move_masked_irq() try to assign affinity before calling chip set_affinity(). Some archs are assigning it in ->set_affinity() again. We do something like: cpumask_cpy(desc->affinity, mask); desc->chip->set_affinity(mask); But in the failure path, affinity should not be touched - otherwise we'll end up with a different affinity mask despite the failure to migrate the IRQ. So try to update the afffinity only if set_affinity returns with 0. Also call irq_set_thread_affinity accordingly. v2: update after "irq, x86: Remove IRQ_DISABLED check in process context IRQ move" v3: according to Ingo, change set_affinity() in irq_chip should return int. v4: update comments by removing moving irq_desc code. [ Impact: fix /proc/irq/*/smp_affinity setting corner case bug ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <49F65509.60307@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-23genirq: do not execute DEBUG_SHIRQ when irq setup failedLuis Henriques1-1/+1
When requesting an IRQ, the DEBUG_SHIRQ code executes a fake IRQ just to make sure the driver is ready to receive an IRQ immediately. The problem was that this fake IRQ was being executed even if interrupt line failed to be allocated by __setup_irq. Signed-off-by: Luis Henriques <henrix@sapo.pt> LKML-Reference: <20090401170635.GA4392@hades.domain.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ fixed bug pointed out by a warning reported by Stephen Rothwell ] Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14x86, irq: Remove IRQ_DISABLED check in process context IRQ movePallipadi, Venkatesh1-3/+2
As discussed in the thread here: http://marc.info/?l=linux-kernel&m=123964468521142&w=2 Eric W. Biederman observed: > It looks like some additional bugs have slipped in since last I looked. > > set_irq_affinity does this: > ifdef CONFIG_GENERIC_PENDING_IRQ > if (desc->status & IRQ_MOVE_PCNTXT || desc->status & IRQ_DISABLED) { > cpumask_copy(desc->affinity, cpumask); > desc->chip->set_affinity(irq, cpumask); > } else { > desc->status |= IRQ_MOVE_PENDING; > cpumask_copy(desc->pending_mask, cpumask); > } > #else > > That IRQ_DISABLED case is a software state and as such it has nothing to > do with how safe it is to move an irq in process context. [...] > > The only reason we migrate MSIs in interrupt context today is that there > wasn't infrastructure for support migration both in interrupt context > and outside of it. Yes. The idea here was to force the MSI migration to happen in process context. One of the patches in the series did disable_irq(dev->irq); irq_set_affinity(dev->irq, cpumask_of(dev->cpu)); enable_irq(dev->irq); with the above patch adding irq/manage code check for interrupt disabled and moving the interrupt in process context. IIRC, there was no IRQ_MOVE_PCNTXT when we were developing this HPET code and we ended up having this ugly hack. IRQ_MOVE_PCNTXT was there when we eventually submitted the patch upstream. But, looks like I did a blind rebasing instead of using IRQ_MOVE_PCNTXT in hpet MSI code. Below patch fixes this. i.e., revert commit 932775a4ab622e3c99bd59f14cc and add PCNTXT to HPET MSI setup. Also removes copying of desc->affinity in generic code as set_affinity routines are doing it internally. Reported-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Li Shaohua" <shaohua.li@intel.com> Cc: Gary Hade <garyhade@us.ibm.com> Cc: "lcm@us.ibm.com" <lcm@us.ibm.com> Cc: suresh.b.siddha@intel.com LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06Merge branch 'linus' into irq/threadedIngo Molnar1-7/+24
Conflicts: include/linux/irq.h kernel/irq/handle.c
2009-03-30PM: Introduce functions for suspending and resuming device interruptsRafael J. Wysocki1-7/+24
Introduce helper functions allowing us to prevent device drivers from getting any interrupts (without disabling interrupts on the CPU) during suspend (or hibernation) and to make them start to receive interrupts again during the subsequent resume. These functions make it possible to keep timer interrupts enabled while the "late" suspend and "early" resume callbacks provided by device drivers are being executed. In turn, this allows device drivers' "late" suspend and "early" resume callbacks to sleep, execute ACPI callbacks etc. The functions introduced here will be used to rework the handling of interrupts during suspend (hibernation) and resume. Namely, interrupts will only be disabled on the CPU right before suspending sysdevs, while device drivers will be prevented from receiving interrupts, with the help of the new helper function, before their "late" suspend callbacks run (and analogously during resume). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Ingo Molnar <mingo@elte.hu>
2009-03-27Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2Ingo Molnar1-6/+6
Conflicts: arch/parisc/kernel/irq.c arch/x86/include/asm/fixmap_64.h arch/x86/include/asm/setup.h kernel/irq/handle.c Semantic merge: arch/x86/include/asm/fixmap.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-24genirq: threaded irq handlers review fixupsThomas Gleixner1-10/+7
Delta patch to address the review comments. - Implement warning when IRQ_WAKE_THREAD is requested and no thread handler installed - coding style fixes Pointed-out-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-03-24genirq: add threaded interrupt handler supportThomas Gleixner1-13/+179
Add support for threaded interrupt handlers: A device driver can request that its main interrupt handler runs in a thread. To achive this the device driver requests the interrupt with request_threaded_irq() and provides additionally to the handler a thread function. The handler function is called in hard interrupt context and needs to check whether the interrupt originated from the device. If the interrupt originated from the device then the handler can either return IRQ_HANDLED or IRQ_WAKE_THREAD. IRQ_HANDLED is returned when no further action is required. IRQ_WAKE_THREAD causes the genirq code to invoke the threaded (main) handler. When IRQ_WAKE_THREAD is returned handler must have disabled the interrupt on the device level. This is mandatory for shared interrupt handlers, but we need to do it as well for obscure x86 hardware where disabling an interrupt on the IO_APIC level redirects the interrupt to the legacy PIC interrupt lines. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2009-03-23Merge branch 'cpus4096' into irq/threadedThomas Gleixner1-6/+6
Conflicts: arch/parisc/kernel/irq.c kernel/irq/handle.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-03-16Merge branches 'irq/genirq' and 'linus' into irq/coreIngo Molnar1-78/+104
2009-03-13genirq: use kzalloc instead of explicit zero initializationThomas Gleixner1-3/+1
Impact: simplification Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
2009-03-13genirq: remove redundant if conditionThomas Gleixner1-1/+1
Impact: cleanup The code is only compiled if CONFIG_GENERIC_HARDIRQS=y so another check for this define in the code is redundant. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-03-12irq: export remove_irq() and setup_irq() symbolsMagnus Damm1-0/+2
Export the setup_irq() and remove_irq() symbols. I'd like to export these functions since I have timer code that needs to use setup_irq() early on (too early for request_irq()), and the same code can also be compiled as a module. Signed-off-by: Magnus Damm <damm@igel.co.jp> LKML-Reference: <20090312120559.2926.82371.sendpatchset@rx1.opensource.se> [ changed to _GPL as these are special APIs deep inside the irq layer. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12irq: match remove_irq() args with setup_irq()Magnus Damm1-9/+17
Modify remove_irq() to match setup_irq(). Signed-off-by: Magnus Damm <damm@igel.co.jp> LKML-Reference: <20090312120551.2926.43942.sendpatchset@rx1.opensource.se> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-12irq: add remove_irq() for freeing of setup_irq() irqsMagnus Damm1-13/+26
Impact: add new API This patch adds a remove_irq() function for releasing interrupts requested with setup_irq(). Without this patch we have no way of releasing such interrupts since free_irq() today tries to kfree() the irqaction passed with setup_irq(). Signed-off-by: Magnus Damm <damm@igel.co.jp> LKML-Reference: <20090312120542.2926.56609.sendpatchset@rx1.opensource.se> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02Merge branch 'linus' into irq/genirqIngo Molnar1-9/+1
2009-02-17irq: name 'p' variables a bit betterIngo Molnar1-11/+11
'p' stands for pointer - make it clear in setup_irq() and free_irq() what kind of pointer it is. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-17irq: further clean up the free_irq() code flowIngo Molnar1-7/+4
Linus noticed that the 'pp' variable can be eliminated altogether, and the loop can be cleaned up further. Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15irq: refactor and clean up the free_irq() code flowIngo Molnar1-47/+54
Impact: cleanup - separate out the loop from the actual freeing logic, this wins us two indentation levels allowing a number of followup prettifications - turn the WARN_ON() into a more informative WARN(). - clean up the comments and the code flow some more Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-15irq: clean up manage.cIngo Molnar1-6/+7
- make printk message git-greppable - fix a few style details Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13Merge branches 'irq/genirq', 'irq/sparseirq' and 'irq/urgent' into irq/coreIngo Molnar1-6/+6
2009-02-13irq: use GFP_KERNEL for action allocation in request_irq()Johannes Weiner1-1/+1
request_irq() calls into proc code via __setup_irq() which is not safe in an atomic context, so request_irq() can itself use the more reliable GFP_KERNEL allocation for the action descriptor. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09kernel/irq: fix sparse warning: make symbol staticHannes Eder1-5/+5
While being at it make every occurrence of 'do_irq_select_affinity' have the same signature in terms of signedness of the first argument. Fix this sparse warning: kernel/irq/manage.c:112:5: warning: symbol 'do_irq_select_affinity' was not declared. Should it be static? Also rename do_irq_select_affinity() to setup_affinity() - shorter name and clearer naming. Signed-off-by: Hannes Eder <hannes@hanneseder.net> Acked-by: Matthew Wilcox <matthew@wil.cx> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-30Merge branch 'linus' into core/percpuIngo Molnar1-9/+1
Conflicts: kernel/irq/handle.c
2009-01-28Merge branch 'core/percpu' into x86/coreIngo Molnar1-6/+6
Conflicts: kernel/irq/handle.c
2009-01-27cpumask fallout: Initialize irq_default_affinity earlierDavid Daney1-8/+0
Move the initialization of irq_default_affinity to early_irq_init as core_initcall is too late. irq_default_affinity can be used in init_IRQ and potentially timer and SMP init as well. All of these happen before core_initcall. Moving the initialization to early_irq_init ensures that it is initialized before it is used. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Acked-by: Mike Travis <travis@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-27Make irq_*_affinity depend on CONFIG_GENERIC_HARDIRQS too.David Daney1-1/+1
In interrupt.h these functions are declared only if CONFIG_GENERIC_HARDIRQS is set. We should define them under identical conditions. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-11cpumask: update irq_desc to use cpumask_var_tMike Travis1-6/+6
Impact: reduce memory usage, use new cpumask API. Replace the affinity and pending_masks with cpumask_var_t's. This adds to the significant size reduction done with the SPARSE_IRQS changes. The added functions (init_alloc_desc_masks & init_copy_desc_masks) are in the include file so they can be inlined (and optimized out for the !CONFIG_CPUMASKS_OFFSTACK case.) [Naming chosen to be consistent with the other init*irq functions, as well as the backwards arg declaration of "from, to" instead of the more common "to, from" standard.] Includes a slight change to the declaration of struct irq_desc to embed the pending_mask within ifdef(CONFIG_SMP) to be consistent with other references, and some small changes to Xen. Tested: sparse/non-sparse/cpumask_offstack/non-cpumask_offstack/nonuma/nosmp on x86_64 Signed-off-by: Mike Travis <travis@sgi.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: virtualization@lists.osdl.org Cc: xen-devel@lists.xensource.com Cc: Yinghai Lu <yhlu.kernel@gmail.com>
2009-01-01cpumask: convert kernel/irqRusty Russell1-2/+9
Impact: Reduce stack usage, use new cpumask API. ALPHA mod! Main change is that irq_default_affinity becomes a cpumask_var_t, so treat it as a pointer (this effects alpha). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-31Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6Rusty Russell1-6/+21
Conflicts: arch/x86/kernel/io_apic.c
2008-12-30Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tipLinus Torvalds1-6/+9
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, sparseirq: clean up Kconfig entry x86: turn CONFIG_SPARSE_IRQ off by default sparseirq: fix numa_migrate_irq_desc dependency and comments sparseirq: add kernel-doc notation for new member in irq_desc, -v2 locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP sparseirq, xen: make sure irq_desc is allocated for interrupts sparseirq: fix !SMP building, #2 x86, sparseirq: move irq_desc according to smp_affinity, v7 proc: enclose desc variable of show_stat() in CONFIG_SPARSE_IRQ sparse irqs: add irqnr.h to the user headers list sparse irqs: handle !GENIRQ platforms sparseirq: fix !SMP && !PCI_MSI && !HT_IRQ build sparseirq: fix Alpha build failure sparseirq: fix typo in !CONFIG_IO_APIC case x86, MSI: pass irq_cfg and irq_desc x86: MSI start irq numbering from nr_irqs_gsi x86: use NR_IRQS_LEGACY sparse irq_desc[] array: core kernel and x86 changes genirq: record IRQ_LEVEL in irq_desc[] irq.h: remove padding from irq_desc on 64bits