kernel.git/kernel/irq/manage.c, branch linux-2.6.31.y

genirq: Wake up irq thread after action has been installed

2009-08-18T15:22:43Z

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 Signed-off-by: Thomas Gleixner Tested-by: Michael Buesch

genirq: prevent wakeup of freed irq thread

2009-08-13T21:09:27Z

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 Signed-off-by: Thomas Gleixner

genirq: Fix UP compile failure caused by irq_thread_check_affinity

2009-07-22T21:18:46Z

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 LKML-Reference: <20090722222232.2eb3e1c4@neptune.home> Signed-off-by: Thomas Gleixner

genirq: Delegate irq affinity setting to the irq thread

2009-07-21T12:35:07Z

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 LKML-Reference:

Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-06-20T18:30:01Z

* '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

genirq: fix comment to say IRQ_WAKE_THREAD

2009-05-12T20:11:29Z

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 LKML-Reference: Signed-off-by: Thomas Gleixner

irq: only update affinity if ->set_affinity() is sucessfull

2009-04-28T10:21:16Z

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 Cc: Andrew Morton Cc: Suresh Siddha Cc: "Eric W. Biederman" Cc: Rusty Russell LKML-Reference: <49F65509.60307@kernel.org> Signed-off-by: Ingo Molnar

x86, irq: Remove IRQ_DISABLED check in process context IRQ move

2009-04-14T13:21:13Z

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" Signed-off-by: Venkatesh Pallipadi Acked-by: "Eric W. Biederman" Cc: "Li Shaohua" Cc: Gary Hade Cc: "lcm@us.ibm.com" Cc: suresh.b.siddha@intel.com LKML-Reference: <20090413222058.GB8211@linux-os.sc.intel.com> Signed-off-by: Ingo Molnar

Merge branch 'linus' into irq/threaded

2009-04-05T23:41:22Z

Conflicts: include/linux/irq.h kernel/irq/handle.c

PM: Introduce functions for suspending and resuming device interrupts

2009-03-30T19:46:54Z

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 Acked-by: Ingo Molnar