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2010-11-01Merge branches 'irq-core-for-linus' and 'core-locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Fix up irq_node() for irq_data changes. genirq: Add single IRQ reservation helper genirq: Warn if enable_irq is called before irq is set up * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: semaphore: Remove mutex emulation staging: Final semaphore cleanup jbd2: Convert jbd2_slab_create_sem to mutex hpfs: Convert sbi->hpfs_creation_de to mutex Fix up trivial change/delete conflicts with deleted 'dream' drivers (drivers/staging/dream/camera/{mt9d112.c,mt9p012_fox.c,mt9t013.c,s5k3e2fx.c})
2010-10-28/proc/stat: fix scalability of irq sum of all cpuKAMEZAWA Hiroyuki
In /proc/stat, the number of per-IRQ event is shown by making a sum each irq's events on all cpus. But we can make use of kstat_irqs(). kstat_irqs() do the same calculation, If !CONFIG_GENERIC_HARDIRQ, it's not a big cost. (Both of the number of cpus and irqs are small.) If a system is very big and CONFIG_GENERIC_HARDIRQ, it does for_each_irq() for_each_cpu() - look up a radix tree - read desc->irq_stat[cpu] This seems not efficient. This patch adds kstat_irqs() for CONFIG_GENRIC_HARDIRQ and change the calculation as for_each_irq() look up radix tree for_each_cpu() - read desc->irq_stat[cpu] This reduces cost. A test on (4096cpusp, 256 nodes, 4592 irqs) host (by Jack Steiner) %time cat /proc/stat > /dev/null Before Patch: 2.459 sec After Patch : .561 sec [akpm@linux-foundation.org: unexport kstat_irqs, coding-style tweaks] [akpm@linux-foundation.org: fix unused variable 'per_irq_sum'] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Jack Steiner <steiner@sgi.com> Acked-by: Jack Steiner <steiner@sgi.com> Cc: Yinghai Lu <yinghai@kernel.org> 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>
2010-10-22genirq: Warn if enable_irq is called before irq is set upThomas Gleixner
The recent changes in the genirq core unearthed a bug in arch/um which called enable_irq() before the interrupt was set up. Warn and return instead of crashing the machine with a NULL pointer dereference. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Weinberger <richard@nod.at>
2010-10-12genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y buildThomas Gleixner
This option can be set to verify the full conversion to the new chip functions. Fix the fallout of the patch rework, so the core code compiles and works with it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12genirq: Switch sparse_irq allocator to GFP_KERNELThomas Gleixner
The allocator functions are now called outside of preempt disabled regions. Switch to GFP_KERNEL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Make sparse_lock a mutexThomas Gleixner
No callers from atomic regions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove the now unused sparse irq leftoversThomas Gleixner
The move_irq_desc() function was only used due to the problem that the allocator did not free the old descriptors. So the descriptors had to be moved in create_irq_nr(). That's history. The code would have never been able to move active interrupt descriptors on affinity settings. That can be done in a completely different way w/o all this horror. Remove all of it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Sanitize dynamic irq handlingThomas Gleixner
Use the cleanup functions of the dynamic allocator. No need to have separate implementations. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove arch_init_chip_data()Thomas Gleixner
This function should have not been there in the first place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Query arch for number of early descriptorsThomas Gleixner
sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go ahead and allocate more. Use the unused return value of arch_probe_nr_irqs() to let the architecture return the number of early allocations. Fix up all users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Use sane sparse allocatorThomas Gleixner
Make irq_to_desc_alloc_node() a wrapper around the new allocator. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Implement irq reservationThomas Gleixner
Mark a range of interrupts as allocated. In the SPARSE_IRQ=n case we need this to update the bitmap for the legacy irqs so the enumerator via irq_get_next_irq() works. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12genirq: Implement sane enumerationThomas Gleixner
Use the allocator bitmap to lookup active interrupts. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Prepare proc for real sparse irq supportThomas Gleixner
/proc/irq never removes any entries, but when irq descriptors can be freed for real this is necessary. Otherwise we'd reference a freed descriptor in /proc/irq/N Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Implement a sane sparse_irq allocatorThomas Gleixner
The current sparse_irq allocator has several short comings due to failures in the design or the lack of it: - Requires iteration over the number of active irqs to find a free slot (Some architectures have grown their own workarounds for this) - Removal of entries is not possible - Racy between create_irq_nr and destroy_irq (plugged by horrible callbacks) - Migration of active irq descriptors is not possible - No bulk allocation of irq ranges - Sprinkeled irq_desc references all over the place outside of kernel/irq/ (The previous chip functions series is addressing this issue) Implement a sane allocator which fixes the above short comings (though migration of active descriptors needs a full tree wide cleanup of the direct and mostly unlocked access to irq_desc). The new allocator still uses a radix_tree, but uses a bitmap for keeping track of allocated irq numbers. That allows: - Fast lookup of a free slot - Allows the removal of descriptors - Prevents the create/destroy race - Bulk allocation of consecutive irq ranges - Basic design is ready for migration of life descriptors after further cleanups The bitmap is also used in the SPARSE_IRQ=n case for lookup and raceless (de)allocation of irq numbers. So it removes the requirement for looping through the descriptor array to find slots. Right now it uses sparse_irq_lock to protect the bitmap and the radix tree, but after cleaning up all users we should be able convert that to a mutex and to switch the radix_tree and decriptor allocations to GFP_KERNEL. [ Folded in a bugfix from Yinghai Lu ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Provide default irq init flagsThomas Gleixner
Arch code sets it's own irq_desc.status flags right after boot and for dynamically allocated interrupts. That might involve iterating over a huge array. Allow ARCH_IRQ_INIT_FLAGS to set separate flags aside of IRQ_DISABLED which is the default. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove export of kstat_irqs_cpuThomas Gleixner
The statistics accessor is only used by proc/stats and show_interrupts(). Both are compiled in. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove early_init_irq_lock_class()Thomas Gleixner
early_init_irq_lock_class() is called way before anything touches the irq descriptors. In case of SPARSE_IRQ=y this is a NOP operation because the radix tree is empty at this point. For the SPARSE_IRQ=n case it's sufficient to set the lock class in early_init_irq(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Distangle kernel/irq/handle.cThomas Gleixner
kernel/irq/handle.c has become a dumpground for random code in random order. Split out the irq descriptor management and the dummy irq_chip implementation into separate files. Cleanup the include maze while at it. No code change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Sanitize irq_data accessorsThomas Gleixner
Get the data structure from the core and provide inline wrappers to access the irq_data members. Provide accessor inlines for irq_data as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Provide status modifierThomas Gleixner
Provide a irq_desc.status modifier function to cleanup the direct access to irq_desc in arch and driver code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Distangle irq.hThomas Gleixner
Move irq_desc and internal functions out of irq.h Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide config option to disable deprecated codeThomas Gleixner
This option covers now the old chip functions and the irq_desc data fields which are moving to struct irq_data. More stuff will follow. Pretty handy for testing a conversion, whether something broke or not. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->retrigger()Thomas Gleixner
Wrap the old chip function retrigger() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121843.025801092@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->set_wake()Thomas Gleixner
Wrap the old chip function set_wake() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.927527393@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->set_type()Thomas Gleixner
Wrap the old chip function set_type() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.832261548@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->set_affinity()Thomas Gleixner
Wrap the old chip function set_affinity() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.732894108@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->startup()Thomas Gleixner
Wrap the old chip function startup() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.635152961@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->disable()/shutdown()Thomas Gleixner
Wrap the old chip functions disable() and shutdown() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.532070631@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->enable()Thomas Gleixner
Wrap the old chip function enable() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.437159182@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->eoi()Thomas Gleixner
Wrap the old chip function eoi() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.339657617@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->mask_ack()Thomas Gleixner
Wrap the old chip function mask_ack() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.240806983@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->ack()Thomas Gleixner
Wrap the old chip function ack() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.142624725@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->unmask()Thomas Gleixner
Wrap the old chip function unmask() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121842.043608928@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for chip->mask()Thomas Gleixner
Wrap the old chip function mask() until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121841.940355859@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide compat handling for bus_lock/bus_sync_unlockThomas Gleixner
Wrap the old chip functions for bus_lock/bus_sync_unlock until the migration is complete and the old chip functions are removed. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121841.842536121@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Add new functions to dummy chipsThomas Gleixner
The compat functions go away when the core code is converted. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Convert core code to irq_dataThomas Gleixner
Convert all references in the core code to orq, chip, handler_data, chip_data, msi_desc, affinity to irq_data.* Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Create irq_dataThomas Gleixner
Low level chip functions need access to irq_desc->handler_data, irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq number to the low level functions, so they need to lookup irq_desc. With sparse irq this means a radix tree lookup. We could hand down irq_desc itself, but low level chip functions have no need to fiddle with it directly and we want to restrict access to irq_desc further. Preparatory patch for new chip functions. Note, that the ugly anon union/struct is there to avoid a full tree wide clean up for now. This is not going to last 3 years like __do_IRQ() Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121841.645542300@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-04genirq: Provide KconfigThomas Gleixner
The generic irq Kconfig options are copied around all archs. Provide a generic Kconfig file which can be included. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20100927121843.217333624@linutronix.de> Reviewed-by: H. Peter Anvin <hpa@zytor.com> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-23genirq: Cleanup irq_chip->typename leftoversThomas Gleixner
3 years transition phase is enough. Cleanup the last users and remove the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Leo Chen <leochen@broadcom.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net>
2010-07-29irq: Add new IRQ flag IRQF_NO_SUSPENDIan Campbell
A small number of users of IRQF_TIMER are using it for the implied no suspend behaviour on interrupts which are not timer interrupts. Therefore add a new IRQF_NO_SUSPEND flag, rename IRQF_TIMER to __IRQF_TIMER and redefine IRQF_TIMER in terms of these new flags. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: xen-devel@lists.xensource.com Cc: linux-input@vger.kernel.org Cc: linuxppc-dev@ozlabs.org Cc: devicetree-discuss@lists.ozlabs.org LKML-Reference: <1280398595-29708-1-git-send-email-ian.campbell@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-06-09genirq: Deal with desc->set_type() changing desc->chipThomas Gleixner
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
2010-05-12genirq: Clear CPU mask in affinity_hint when none is providedPeter P Waskiewicz Jr
When an interrupt is disabled and torn down, the CPU mask returned through affinity_hint right now is all CPUs. Also, for drivers that don't provide an affinity_hint mask, this can be misleading. There should be no hint at all, meaning an empty CPU mask. [ tglx: use zalloc_cpumask_var instead of clearing it under the lock ] 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: <20100505205638.5426.87189.stgit@ppwaskie-hc2.jf.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-05-03genirq: Add CPU mask affinity hintPeter P Waskiewicz Jr
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 Gleixner
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: Run irq handlers with interrupts disabledIngo Molnar
Running interrupt handlers with interrupts enabled can cause stack overflows. That has been observed with multiqueue NICs delivering all their interrupts to a single core. We might band aid that somehow by checking the interrupt stacks, but the real safe fix is to run the irq handlers with interrupts disabled. Drivers for whacky hardware still can reenable them in the handler itself, if the need arises. (They do already due to lockdep) The risk of doing this is rather low: - lockdep already enforces this - CONFIG_NOHZ has shaken out the drivers which relied on jiffies updates - time keeping is not longer sensitive to the timer interrupt being delayed Signed-off-by: Ingo Molnar <mingo@elte.hu> 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: <20100326000405.758579387@linutronix.de>
2010-04-13genirq: Introduce request_any_context_irq()Marc Zyngier
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>
2010-04-13Merge branch 'linus' into irq/coreThomas Gleixner
Reason: Get the upstream IRQF_DISABLED related changes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-04-06Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Force MSI irq handlers to run with interrupts disabled