Commit Graph

495 Commits

Author SHA1 Message Date
Thomas Gleixner 1277a5325a genirq: Simplify handle_irq_event()
Now that all core users are converted one layer can go.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:13 +01:00
Thomas Gleixner 0877d66257 genirq: Use handle_irq_event() in the spurious poll code
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:13 +01:00
Thomas Gleixner 849f061c25 genirq: Use handle_perpcu_event() in handle_percpu_irq()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:12 +01:00
Thomas Gleixner a60a5dc2db genirq: Use handle_irq_event() in handle_edge_irq()
It's safe to drop the IRQ_INPROGRESS flag between action chain walks
as we are protected by desc->lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:12 +01:00
Thomas Gleixner a7ae4de5c8 genirq: Use handle_irq_event() in handle_fasteoi_irq()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:12 +01:00
Thomas Gleixner 1529866c63 genirq: Use handle_irq_event() in handle_level_irq()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:12 +01:00
Thomas Gleixner 107781e721 genirq: Use handle_irq_event() in handle_simple_irq()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:11 +01:00
Thomas Gleixner 4912609f22 genirq: Implement handle_irq_event()
Core code replacement for the ugly camel case. It contains all the
code which is shared in all handlers.

     clear status flags
     set INPROGRESS flag
     unlock
     call action chain
     note_interrupt
     lock
     clr INPROGRESS flag

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:11 +01:00
Thomas Gleixner d78f8dd36b genirq: Do not fiddle with IRQ_MASKED in handle_edge_irq()
IRQ_MASKED is set in mask_ack_irq() anyway. Remove it from
handle_edge_irq() to allow simpler ab^HHreuse of that function.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110202212551.918484270@linutronix.de>
2011-02-19 12:58:11 +01:00
Thomas Gleixner 3aae994fb0 genirq: Consolidate IRQ_DISABLED
Handle IRQ_DISABLED consistent.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:11 +01:00
Thomas Gleixner 50f7c03275 genirq: Remove default magic
Now that everything uses the wrappers, we can remove the default
functions. None of those functions is performance critical.

That makes the IRQ_MASKED flag tracking fully consistent.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:10 +01:00
Thomas Gleixner 87923470c7 genirq: Consolidate disable/enable
Create irq_disable/enable and use them to keep the flags consistent.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:10 +01:00
Thomas Gleixner 4699923861 genirq: Consolidate startup/shutdown of interrupts
Aside of duplicated code some of the startup/shutdown sites do not
handle the MASKED/DISABLED flags and the depth field at all. Move that
to a helper function and take care of it there.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110202212551.787481468@linutronix.de>
2011-02-19 12:58:10 +01:00
Thomas Gleixner 3b56f0585f genirq: Remove bogus conditional
The if (chip->irq_shutdown) check will always evaluate to true, as we
fill in chip->irq_shutdown with default_shutdown in
irq_chip_set_defaults() if the chip does not provide its own function.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110202212551.667607458@linutronix.de>
2011-02-19 12:58:10 +01:00
Thomas Gleixner 1535dfacbf genirq: Move irq thread flags to core
Soleley used in core code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:09 +01:00
Thomas Gleixner fe200ae48e genirq: Mark polled irqs and defer the real handler
With the chip.end() function gone we might run into a situation where
a poll call runs and the real interrupt comes in, sees IRQ_INPROGRESS
and disables the line. That might be a perfect working one, which will
then be masked forever.

So mark them polled while the poll runs. When the real handler sees
IRQ_INPROGRESS it checks the poll flag and waits for the polling to
complete. Add the necessary amount of sanity checks to it to avoid
deadlocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:09 +01:00
Thomas Gleixner d05c65fff0 genirq: spurious: Run only one poller at a time
No point in running concurrent pollers which confuse each other by
setting PENDING.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:09 +01:00
Thomas Gleixner c7259cd7af genirq: Do not poll disabled, percpu and timer interrupts
There is no point in polling disabled lines.

percpu does not make sense at all because we only poll on the cpu
we're currently running on. Also polling per_cpu interrupts is racy as
hell. The handler runs without locking so we might get a huge
surprise.

If the timer interrupt needs polling, then we wont get there anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:09 +01:00
Thomas Gleixner fa27271bc8 genirq: Fixup poll handling
try_one_irq() contains redundant code and lots of useless checks for
shared interrupts. Check for shared before setting IRQ_INPROGRESS and
then call handle_IRQ_event() while pending. Shorter version with the
same functionality.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:08 +01:00
Thomas Gleixner b738a50a20 genirq: Warn when handler enables interrupts
We run all handlers with interrupts disabled and expect them not to
enable them. Warn when we catch one who does.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:08 +01:00
Thomas Gleixner 1082687e8d genirq: Plug race in report_bad_irq()
We cannot walk the action chain unlocked. Even if IRQ_INPROGRESS is
set an action can be removed and we follow a null pointer. It's safe
to take the lock there, because the code which removes the action will
call synchronize_irq() which waits unlocked for IRQ_INPROGRESS going
away.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:08 +01:00
Thomas Gleixner 2b879eaf09 genirq: Remove redundant thread affinity setting
Thread affinity is already set by setup_affinity().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:08 +01:00
Thomas Gleixner 3b8249e759 genirq: Do not copy affinity before set
While rumaging through arch code I found that there are a few
workarounds which deal with the fact that the initial affinity setting
from request_irq() copies the mask into irq_data->affinity before the
chip code is called. In the normal path we unconditionally copy the
mask when the chip code returns 0.

Copy after the code is called and add a return code
IRQ_SET_MASK_OK_NOCOPY for the chip functions, which prevents the
copy. That way we see the real mask when the chip function decided to
truncate it further as some arches do. IRQ_SET_MASK_OK is 0, which is
the current behaviour.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:07 +01:00
Thomas Gleixner 569bda8df1 genirq: Always apply cpu online mask
If the affinity had been set by the user, then a later request_irq()
will honour that setting. But online cpus can have changed. So apply
the online mask and for this case as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:07 +01:00
Thomas Gleixner b008207cbd genirq: Rremove redundant check
IRQ_NO_BALANCING is already checked in irq_can_set_affinity() above,
no need to check it again.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:07 +01:00
Thomas Gleixner 1fa46f1f07 genirq: Simplify affinity related code
There is lot of #ifdef CONFIG_GENERIC_PENDING_IRQ along with
duplicated code in the irq core. Move the #ifdeffery into one place
and cleanup the code so it's readable. No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:07 +01:00
Thomas Gleixner a0cd9ca2b9 genirq: Namespace cleanup
The irq namespace has become quite convoluted. My bad.  Clean it up
and deprecate the old functions. All new functions follow the scheme:

irq number based:
    irq_set/get/xxx/_xxx(unsigned int irq, ...)

irq_data based:
	 irq_data_set/get/xxx/_xxx(struct irq_data *d, ....)

irq_desc based:
	 irq_desc_get_xxx(struct irq_desc *desc)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:06 +01:00
Thomas Gleixner 43abe43ce0 genirq: Add missing buslock to set_irq_type(), set_irq_wake()
chips behind a slow bus cannot update the chip under desc->lock, but
we miss the chip_buslock/chip_bus_sync_unlock() calls around the set
type and set wake functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:06 +01:00
Thomas Gleixner e7bcecb7b1 genirq: Make nr_irqs runtime expandable
We face more and more the requirement to expand nr_irqs at
runtime. The reason are irq expanders which can not be detected in the
early boot stage. So we speculate nr_irqs to have enough room. Further
Xen needs extra irq numbers and we really want to avoid adding more
"detection" code into the early boot. There is no real good reason why
we need to limit nr_irqs at early boot.

Allow the allocation code to expand nr_irqs. We have already 8k extra
number space in the allocation bitmap, so lets use it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:06 +01:00
Thomas Gleixner 218502bfe6 Merge branch 'irq/urgent' into irq/core
Reason: Further patches are conflicting with mainline fixes

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:56:43 +01:00
Thomas Gleixner 6d83f94db9 genirq: Disable the SHIRQ_DEBUG call in request_threaded_irq for now
With CONFIG_SHIRQ_DEBUG=y we call a newly installed interrupt handler
in request_threaded_irq().

The original implementation (commit a304e1b8) called the handler
_BEFORE_ it was installed, but that caused problems with handlers
calling disable_irq_nosync(). See commit 377bf1e4.

It's braindead in the first place to call disable_irq_nosync in shared
handlers, but ....

Moving this call after we installed the handler looks innocent, but it
is very subtle broken on SMP.

Interrupt handlers rely on the fact, that the irq core prevents
reentrancy.

Now this debug call violates that promise because we run the handler
w/o the IRQ_INPROGRESS protection - which we cannot apply here because
that would result in a possibly forever masked interrupt line.

A concurrent real hardware interrupt on a different CPU results in
handler reentrancy and can lead to complete wreckage, which was
unfortunately observed in reality and took a fricking long time to
debug.

Leave the code here for now. We want this debug feature, but that's
not easy to fix. We really should get rid of those
disable_irq_nosync() abusers and remove that function completely.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: stable@kernel.org # .28 -> .37
2011-02-19 12:11:13 +01:00
Thomas Gleixner c1ee626428 genirq: Prevent access beyond allocated_irqs bitmap
Lars-Peter Clausen pointed out:

   I stumbled upon this while looking through the existing archs using
   SPARSE_IRQ.  Even with SPARSE_IRQ the NR_IRQS is still the upper
   limit for the number of IRQs.

   Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with
   IRQ_BOARD_START being the number of IRQs used by the core.

   In various machine files the nr_irqs field of the ARM machine
   defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS".

   As a result "nr_irqs" will greater then NR_IRQS which then again
   causes the "allocated_irqs" bitmap in the core irq code to be
   accessed beyond its size overwriting unrelated data.

The core code really misses a sanity check there.

This went unnoticed so far as by chance the compiler/linker places
data behind that bitmap which gets initialized later on those affected
platforms.

So the obvious fix would be to add a sanity check in early_irq_init()
and break all affected platforms. Though that check wants to be
backported to stable as well, which will require to fix all known
problematic platforms and probably some more yet not known ones as
well. Lots of churn.

A way simpler solution is to allocate a slightly larger bitmap and
avoid the whole churn w/o breaking anything. Add a few warnings when
an arch returns utter crap.

Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # .37
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2011-02-19 12:10:51 +01:00
Thomas Gleixner 51327ada71 Merge branch 'irq/for-mips' into irq/core
Reason: irq/for-mips is provided for mips to make core independent
        progress. Merge it into irq/core to avoid conflicts

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-11 00:27:03 +01:00
David Daney 986c011ddb genirq: Call bus_lock/unlock functions in setup_irq()
irq_chips that supply .irq_bus_lock/.irq_bus_sync_unlock functions,
expect that the other chip methods will be called inside of calls to
the pair.  If this expectation is not met, things tend to not work.

Make setup_irq() call chip_bus_lock()/chip_bus_sync_unlock() too.

For the vast majority of irq_chips, this will be a NOP as most don't
have these bus lock functions.

[ tglx: No we don't want to call that in __setup_irq(). Way too many
  	error exit pathes. ]

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
LKML-Reference: <1297296265-18680-1-git-send-email-ddaney@caviumnetworks.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-11 00:25:13 +01:00
Thomas Gleixner 44951a60ff genirq: Remove dead code
CONFIG_KSTAT_IRQS_ONDEMAND does not exist. It's not worth to implement
it. Use sparse irqs if you care about memory consumption of the
interrupt layer.

Found by undertaker: http://vamos.informatik.uni-erlangen.de/trac/undertaker

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-08 19:37:13 +01:00
Thomas Gleixner c9a443cdf7 Merge branch 'irq/for-xen' into irq/core
irq/for-xen contains new functionality to avoid Xen private irq
hackery. That branch has a single irq commit and is pulled by Xen to
base their new features on.

Merge it into irq/core as other patches modify the same code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-08 16:38:21 +01:00
Thomas Gleixner dc5f219e88 genirq: Add IRQF_FORCE_RESUME
Xen needs to reenable interrupts which are marked IRQF_NO_SUSPEND in the
resume path. Add a flag to force the reenabling in the resume code.

Tested-and-acked-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-08 16:36:47 +01:00
Thomas Gleixner 285c1a2c3a Merge branch 'irq/urgent' into irq/core
Reason: Get mainline fixes integrated. Further patches conflict with
        them

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-05 21:50:05 +01:00
Thomas Gleixner f1a06390d0 genirq: Prevent irq storm on migration
move_native_irq() masks and unmasks the interrupt line
unconditionally, but the interrupt line might be masked due to a
threaded oneshot handler in progress. Unmasking the line in that case
can lead to interrupt storms. Observed on PREEMPT_RT.

Originally-from: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
2011-02-02 22:15:08 +01:00
Thomas Gleixner 1fb0ef31f4 genirq: Fix affinity notifier fallout
The new code of commit cd7eab44e(genirq: Add IRQ affinity notifiers)
references irq_desc.affinity which fails to compile with
CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED=y.

Use irq_desc.irq_data.affinity instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ben Hutchings <bhutchings@solarflare.com>
2011-01-31 08:57:41 +01:00
Ben Hutchings cd7eab44e9 genirq: Add IRQ affinity notifiers
When initiating I/O on a multiqueue and multi-IRQ device, we may want
to select a queue for which the response will be handled on the same
or a nearby CPU.  This requires a reverse-map of IRQ affinity.  Add a
notification mechanism to support this.

This is based closely on work by Thomas Gleixner <tglx@linutronix.de>.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: linux-net-drivers@solarflare.com
Cc: Tom Herbert <therbert@google.com>
Cc: David Miller <davem@davemloft.net>
LKML-Reference: <1295470904.11126.84.camel@bwh-desktop>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-01-22 17:34:25 +01:00
Thomas Gleixner 1c77ff22f5 genirq: Remove __do_IRQ
All architectures are finally converted. Remove the cruft.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
2011-01-21 11:55:31 +01:00
Eric Dumazet 6c9ae009b2 irq: use per_cpu kstat_irqs
Use modern per_cpu API to increment {soft|hard}irq counters, and use
per_cpu allocation for (struct irq_desc)->kstats_irq instead of an array.

This gives better SMP/NUMA locality and saves few instructions per irq.

With small nr_cpuids values (8 for example), kstats_irq was a small array
(less than L1_CACHE_BYTES), potentially source of false sharing.

In the !CONFIG_SPARSE_IRQ case, remove the huge, NUMA/cache unfriendly
kstat_irqs_all[NR_IRQS][NR_CPUS] array.

Note: we still populate kstats_irq for all possible irqs in
early_irq_init().  We probably could use on-demand allocations.  (Code
included in alloc_descs()).  Problem is not all IRQS are used with a prior
alloc_descs() call.

kstat_irqs_this_cpu() is not used anymore, remove it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:31 -08:00
Peter Zijlstra c9b5f501ef sched: Constify function scope static struct sched_param usage
Function-scope statics are discouraged because they are
easily overlooked and can cause subtle bugs/races due to
their global (non-SMP safe) nature.

Linus noticed that we did this for sched_param - at minimum
make the const.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: Message-ID: <AANLkTinotRxScOHEb0HgFgSpGPkq_6jKTv5CfvnQM=ee@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-07 15:55:45 +01:00
Ingo Molnar 8e9255e6a2 Merge branch 'linus' into sched/core
Merge reason: we want to queue up dependent cleanup

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-08 20:15:29 +01:00
Kenji Kaneshige 25c9170ed6 genirq: Fix incorrect proc spurious output
Since commit a1afb637(switch /proc/irq/*/spurious to seq_file) all
/proc/irq/XX/spurious files show the information of irq 0.

Current irq_spurious_proc_open() passes on NULL as the 3rd argument,
which is used as an IRQ number in irq_spurious_proc_show(), to the
single_open(). Because of this, all the /proc/irq/XX/spurious file
shows IRQ 0 information regardless of the IRQ number.

To fix the problem, irq_spurious_proc_open() must pass on the
appropreate data (IRQ number) to single_open().

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <4CF4B778.90604@jp.fujitsu.com>
Cc: stable@kernel.org [2.6.33+]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-12-01 08:44:26 +01:00
Ingo Molnar 92fd4d4d67 Merge commit 'v2.6.37-rc2' into sched/core
Merge reason: Move to a .37-rc base.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18 13:22:26 +01:00
Linus Torvalds 82279e6bd7 Merge branches 'irq-core-for-linus' and 'core-locking-for-linus' of 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})
2010-10-31 20:40:24 -04:00
KAMEZAWA Hiroyuki 478735e388 /proc/stat: fix scalability of irq sum of all cpu
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>
2010-10-27 18:03:13 -07:00
KOSAKI Motohiro fe7de49f9d sched: Make sched_param argument static in sched_setscheduler() callers
Andrew Morton pointed out almost all sched_setscheduler() callers are
using fixed parameters and can be converted to static.  It reduces runtime
memory use a little.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-23 17:56:48 +02:00
Thomas Gleixner 2656c36699 genirq: Warn if enable_irq is called before irq is set up
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>
2010-10-22 16:10:29 +02:00
Thomas Gleixner c0a19ebc01 genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build
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>
2010-10-12 21:59:55 +02:00
Thomas Gleixner baa0d233af genirq: Switch sparse_irq allocator to GFP_KERNEL
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>
2010-10-12 16:53:45 +02:00
Thomas Gleixner a05a900a51 genirq: Make sparse_lock a mutex
No callers from atomic regions. 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:53:45 +02:00
Thomas Gleixner 78f90d91f3 genirq: Remove the now unused sparse irq leftovers
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>
2010-10-12 16:53:44 +02:00
Thomas Gleixner b7b29338dc genirq: Sanitize dynamic irq handling
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>
2010-10-12 16:53:44 +02:00
Thomas Gleixner b7d0d8258a genirq: Remove arch_init_chip_data()
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>
2010-10-12 16:53:44 +02:00
Thomas Gleixner b683de2b3c genirq: Query arch for number of early descriptors
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>
2010-10-12 16:39:08 +02:00
Thomas Gleixner aa99ec0f3f genirq: Use sane sparse allocator
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>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 06f6c3399e genirq: Implement irq reservation
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>
2010-10-12 16:39:07 +02:00
Thomas Gleixner a98d24b71b genirq: Implement sane enumeration
Use the allocator bitmap to lookup active interrupts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 13bfe99e09 genirq: Prepare proc for real sparse irq support
/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>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 1f5a5b87f7 genirq: Implement a sane sparse_irq allocator
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>
2010-10-12 16:39:07 +02:00
Thomas Gleixner 1318a481fc genirq: Provide default irq init flags
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>
2010-10-12 16:39:06 +02:00
Thomas Gleixner d895f51ebb genirq: Remove export of kstat_irqs_cpu
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>
2010-10-12 16:39:06 +02:00
Thomas Gleixner 154cd387cd genirq: Remove early_init_irq_lock_class()
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>
2010-10-12 16:39:06 +02:00
Thomas Gleixner 3795de236d genirq: Distangle kernel/irq/handle.c
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>
2010-10-12 16:39:05 +02:00
Thomas Gleixner f303a6dd12 genirq: Sanitize irq_data accessors
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>
2010-10-12 16:39:05 +02:00
Thomas Gleixner 442471848f genirq: Provide status modifier
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>
2010-10-12 16:39:05 +02:00
Thomas Gleixner e144710b30 genirq: Distangle irq.h
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>
2010-10-12 16:39:04 +02:00
Thomas Gleixner bd15141226 genirq: Provide config option to disable deprecated code
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>
2010-10-04 13:40:24 +02:00
Thomas Gleixner 21e2b8c62c genirq: Provide compat handling for chip->retrigger()
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>
2010-10-04 12:43:50 +02:00
Thomas Gleixner 2f7e99bb9b genirq: Provide compat handling for chip->set_wake()
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>
2010-10-04 12:43:48 +02:00
Thomas Gleixner b2ba2c3003 genirq: Provide compat handling for chip->set_type()
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>
2010-10-04 12:43:47 +02:00
Thomas Gleixner c96b3b3c44 genirq: Provide compat handling for chip->set_affinity()
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>
2010-10-04 12:43:46 +02:00
Thomas Gleixner 37e12df709 genirq: Provide compat handling for chip->startup()
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>
2010-10-04 12:43:44 +02:00
Thomas Gleixner bc310dda41 genirq: Provide compat handling for chip->disable()/shutdown()
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>
2010-10-04 12:43:43 +02:00
Thomas Gleixner c5f756344c genirq: Provide compat handling for chip->enable()
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>
2010-10-04 12:43:42 +02:00
Thomas Gleixner 0c5c15572a genirq: Provide compat handling for chip->eoi()
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>
2010-10-04 12:43:41 +02:00
Thomas Gleixner 9205e31d1a genirq: Provide compat handling for chip->mask_ack()
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>
2010-10-04 12:43:40 +02:00
Thomas Gleixner 22a49163e9 genirq: Provide compat handling for chip->ack()
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>
2010-10-04 12:43:38 +02:00
Thomas Gleixner 0eda58b7f3 genirq: Provide compat handling for chip->unmask()
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>
2010-10-04 12:43:37 +02:00
Thomas Gleixner e2c0f8ff0f genirq: Provide compat handling for chip->mask()
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>
2010-10-04 12:43:36 +02:00
Thomas Gleixner 3876ec9ef3 genirq: Provide compat handling for bus_lock/bus_sync_unlock
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>
2010-10-04 12:43:35 +02:00
Thomas Gleixner a77c463591 genirq: Add new functions to dummy chips
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>
2010-10-04 12:43:34 +02:00
Thomas Gleixner 6b8ff3120c genirq: Convert core code to irq_data
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>
2010-10-04 12:36:26 +02:00
Thomas Gleixner ff7dcd44dd genirq: Create irq_data
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>
2010-10-04 12:27:16 +02:00
Thomas Gleixner d9817ebeee genirq: Provide Kconfig
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>
2010-10-04 11:01:05 +02:00
Thomas Gleixner d1ea13c6e2 genirq: Cleanup irq_chip->typename leftovers
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>
2010-09-23 19:12:26 +02:00
Ian Campbell 685fd0b4ea irq: Add new IRQ flag IRQF_NO_SUSPEND
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>
2010-07-29 13:24:57 +02:00
Thomas Gleixner 4673247562 genirq: Deal with desc->set_type() changing desc->chip
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
2010-06-09 17:05:08 +02:00
Peter P Waskiewicz Jr 4308ad8011 genirq: Clear CPU mask in affinity_hint when none is provided
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>
2010-05-12 11:23:34 +02:00
Peter P Waskiewicz Jr e7a297b0d7 genirq: Add CPU mask affinity hint
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>
2010-05-03 11:50:57 +02:00
Thomas Gleixner 6932bf37be genirq: Remove IRQF_DISABLED from core code
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>
2010-04-13 16:36:40 +02:00
Ingo Molnar e58aa3d2d0 genirq: Run irq handlers with interrupts disabled
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>
2010-04-13 16:36:40 +02:00
Marc Zyngier ae731f8d07 genirq: Introduce request_any_context_irq()
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>
2010-04-13 16:36:39 +02:00
Thomas Gleixner 7c7145f6ac Merge branch 'linus' into irq/core
Reason: Get the upstream IRQF_DISABLED related changes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-04-13 14:12:17 +02:00
Linus Torvalds 94c4fcec01 Merge branch 'irq-core-for-linus' of 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
2010-04-06 13:03:22 -07:00
Thomas Gleixner 753649dbc4 genirq: Force MSI irq handlers to run with interrupts disabled
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
2010-03-31 15:48:38 +02:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00