Commit Graph

95 Commits

Author SHA1 Message Date
Thomas Gleixner
dd3a1db900 genirq: improve include files
Move the irq_desc related iterators out of irq.h, into irqnr.h, also
available via interrupt.h.

This way non-genirq (and even non-hardirq) architectures get the
common definitions and iterators.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-18 14:05:18 +02:00
Thomas Gleixner
2be3b52a57 proc: fixup irq iterator
There is no need for irq_desc here. Even for sparse_irq we can
handle this clever in for_each_irq_nr().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:30 +02:00
Thomas Gleixner
811410fdb6 genirq: add reverse iterator for irq_desc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:30 +02:00
Thomas Gleixner
d6c88a507e genirq: revert dynarray
Revert the dynarray changes. They need more thought and polishing.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:15 +02:00
Thomas Gleixner
ee32c97322 genirq: remove irq_to_desc_alloc
Remove the leftover of sparseirqs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:15 +02:00
Thomas Gleixner
2cc21ef843 genirq: remove sparse irq code
This code is not ready, but we need to rip it out instead of rebasing
as we would lose the APIC/IO_APIC unification otherwise.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:15 +02:00
Thomas Gleixner
c6b7674f32 genirq: use inline function for irq_to_desc
For the non sparse irq case an inline function is perfectly fine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:14 +02:00
Thomas Gleixner
70dd4d992a genirq: consolidate nr_irqs and for_each_irq_desc()
Move all of those to linux/irq.h where they belong.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-16 16:53:14 +02:00
Yinghai Lu
8c464a4b23 sparseirq: move kstat_irqs from kstat to irq_desc - fix
fix non-sparseirq architectures.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:53:04 +02:00
Yinghai Lu
8b8e8c1bf7 x86: remove irqbalance in kernel for 32 bit
This has been deprecated for years, the user space irqbalanced utility
works better with numa, has configurable policies, etc...

Signed-off-by: Yinghai Lu <yhlu.kernel@gmai.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:52 +02:00
Yinghai Lu
6d50bc2683 x86: use 28 bits irq NR for pci msi/msix and ht
also print out irq no in /proc/interrups and /proc/stat in hex, so could
tell bus/dev/func.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:52 +02:00
Yinghai Lu
e420dfb40c x86: put irq_2_iommu pointer into irq_desc
when CONFIG_HAVE_SPARSE_IRQ
preallocate some irq_2_iommu entries, and use get_one_free_irq_2_iomm to
get new one and link to irq_desc if needed.

else will use dyn_array or static array.

v2: <= nr_irqs fix

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:52 +02:00
Yinghai Lu
67fb283e14 irq: separate sparse_irqs from sparse_irqs_free
so later don't need compare with -1U

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:51 +02:00
Yinghai Lu
cb5bc83225 x86_64: rename irq_desc/irq_desc_alloc
change names:

          irq_desc() ==> irq_desc_alloc
	__irq_desc() ==> irq_desc

Also split a few of the uses in lowlevel x86 code.

v2: need to check if desc is null in smp_irq_move_cleanup

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:51 +02:00
Yinghai Lu
46926b67fc generic: add irq_desc in function in parameter
So we could remove some duplicated calling to irq_desc

v2: make sure irq_desc in  init/main.c is not used without generic_hardirqs

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:50 +02:00
Yinghai Lu
2c6927a38f irq: replace loop with nr_irqs with for_each_irq_desc
There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.

Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.

v2: make sure arch without GENERIC_HARDIRQS work too

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:33 +02:00
Yinghai Lu
9059d8fa4a irq: add irq_desc_without_new
add an irq_desc accessor that will not allocate any sparse entry
but returns failure if there's no entry present.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:32 +02:00
Yinghai Lu
7f95ec9e4c x86: move kstat_irqs from kstat to irq_desc
based on Eric's patch ...

together mold it with dyn_array for irq_desc, will allcate kstat_irqs for
nr_irq_desc alltogether if needed. -- at that point nr_cpus is known already.

v2: make sure system without generic_hardirqs works they don't have irq_desc
v3: fix merging
v4: [mingo@elte.hu] fix typo

[ mingo@elte.hu ] irq: build fix

fix:

 arch/x86/xen/spinlock.c: In function 'xen_spin_lock_slow':
 arch/x86/xen/spinlock.c:90: error: 'struct kernel_stat' has no member named 'irqs'

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:32 +02:00
Yinghai Lu
3060d6fe28 x86: put timer_rand_state pointer into irq_desc
irq_timer_state[] is a NR_IRQS sized array that is a side-by array to
the real irq_desc[] array.

Integrate that field into the (now dynamic) irq_desc dynamic array and
save some RAM.

v2: keep the old way to support arch not support irq_desc

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:31 +02:00
Yinghai Lu
08678b0841 generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[]
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.

Preallocate 32 irq_desc, and irq_desc() will try to get more.

( No change in functionality is expected anywhere, except the odd build
  failure where we missed a code site or where a crossing commit itroduces
  new irq_desc[] usage. )

v2: according to Eric, change get_irq_desc() to irq_desc()

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:29 +02:00
Yinghai Lu
d60458b224 irq: make irq_desc to use dyn_array
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-16 16:52:07 +02:00
Ingo Molnar
5fef06e8c8 Merge branch 'linus' into genirq 2008-10-16 16:51:32 +02:00
Thomas Gleixner
8d00a6c8f6 genirq: remove last NO_IDLE_HZ leftovers
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-22 08:39:57 +02:00
Ingo Molnar
a208f37a46 Merge branch 'linus' into x86/x2apic 2008-07-18 22:50:34 +02:00
Suresh Siddha
72b1e22dfc x64, x2apic/intr-remap: generic irq migration support from process context
Generic infrastructure for migrating the irq from the process context in the
presence of CONFIG_GENERIC_PENDING_IRQ.

This will be used later for migrating irq in the presence of
interrupt-remapping.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-12 08:44:55 +02:00
Max Krasnyansky
1840475676 genirq: Expose default irq affinity mask (take 3)
Current IRQ affinity interface does not provide a way to set affinity
for the IRQs that will be allocated/activated in the future.
This patch creates /proc/irq/default_smp_affinity that lets users set
default affinity mask for the newly allocated IRQs. Changing the default
does not affect affinity masks for the currently active IRQs, they
have to be changed explicitly.

Updated based on Paul J's comments and added some more documentation.

Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
Cc: pj@sgi.com
Cc: a.p.zijlstra@chello.nl
Cc: tglx@linutronix.de
Cc: rdunlap@xenotime.net
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-06-05 15:18:30 +02:00
Thomas Gleixner
1adb0850a1 genirq: reenable a nobody cared disabled irq when a new driver arrives
Uwe Kleine-Koenig has some strange hardware where one of the shared
interrupts can be asserted during boot before the appropriate driver
loads. Requesting the shared irq line from another driver result in a
spurious interrupt storm which finally disables the interrupt line.

I have seen similar behaviour on resume before (the hardware does not
work anymore so I can not verify).

Change the spurious disable logic to increment the disable depth and
mark the interrupt with an extra flag which allows us to reenable the
interrupt when a new driver arrives which requests the same irq
line. In the worst case this will disable the irq again via the
spurious trap, but there is a decent chance that the new driver is the
one which can handle the already asserted interrupt and makes the box
usable again.

Eric Biederman said further: This case also happens on a regular basis
in kdump kernels where we deliberately don't shutdown the hardware
before starting the new kernel.  This patch should reduce the need for
using irqpoll in that situation by a small amount.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-and-Acked-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
2008-05-02 13:40:34 +02:00
Russell King
d7b906897e [S390] genirq/clockevents: move irq affinity prototypes/inlines to interrupt.h
> Generic code is not supposed to include irq.h. Replace this include
> by linux/hardirq.h instead and add/replace an include of linux/irq.h
> in asm header files where necessary.
> This change should only matter for architectures that make use of
> GENERIC_CLOCKEVENTS.
> Architectures in question are mips, x86, arm, sh, powerpc, uml and sparc64.
>
> I did some cross compile tests for mips, x86_64, arm, powerpc and sparc64.
> This patch fixes also build breakages caused by the include replacement in
> tick-common.h.

I generally dislike adding optional linux/* includes in asm/* includes -
I'm nervous about this causing include loops.

However, there's a separate point to be discussed here.

That is, what interfaces are expected of every architecture in the kernel.
If generic code wants to be able to set the affinity of interrupts, then
that needs to become part of the interfaces listed in linux/interrupt.h
rather than linux/irq.h.

So what I suggest is this approach instead (against Linus' tree of a
couple of days ago) - we move irq_set_affinity() and irq_can_set_affinity()
to linux/interrupt.h, change the linux/irq.h includes to linux/interrupt.h
and include asm/irq_regs.h where needed (asm/irq_regs.h is supposed to be
rarely used include since not much touches the stacked parent context
registers.)

Build tested on ARM PXA family kernels and ARM's Realview platform
kernels which both use genirq.

[ tglx@linutronix.de: add GENERIC_HARDIRQ dependencies ]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2008-04-17 07:47:05 +02:00
Harvey Harrison
21534301ea Final removal of FASTCALL()/fastcall
All users are gone, remove definitions and comments referring
to them.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-13 16:21:18 -08:00
Ralf Baechle
46f4f8f665 IRQ_NOPROBE helper functions
Probing non-ISA interrupts using the handle_percpu_irq as their handle_irq
method may crash the system because handle_percpu_irq does not check
IRQ_WAITING.  This for example hits the MIPS Qemu configuration.

This patch provides two helper functions set_irq_noprobe and set_irq_probe to
set rsp.  clear the IRQ_NOPROBE flag.  The only current caller is MIPS code
but this really belongs into generic code.

As an aside, interrupt probing these days has become a mostly obsolete if not
dangerous art.  I think Linux interrupts should be changed to default to
non-probing but that's subject of this patch.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-and-tested-by: Rob Landley <rob@landley.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:42 -08:00
Harvey Harrison
ec7015840a Remove fastcall from linux/include
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:31 -08:00
Kevin Hilman
b019e57321 genirq: add unlocked version of set_irq_handler()
Add unlocked version for use by irq_chip.set_type handlers which may
wish to change handler to level or edge handler when IRQ type is
changed.

The normal set_irq_handler() call cannot be used because it tries to
take irq_desc.lock which is already held when the irq_chip.set_type
hook is called.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-12-18 18:05:58 +01:00
Randy Dunlap
5ac4d823fd irq.h fix kernel-doc
Add kernel-doc entry in <linux/irq.h> for:

Warning(linux-2.6.22-git12//include/linux/irq.h:177): No description found for parameter 'last_unhandled'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:41 -07:00
Alan Cox
4f27c00bf8 Improve behaviour of spurious IRQ detect
Currently we handle spurious IRQ activity based upon seeing a lot of
invalid interrupts, and we clear things back on the base of lots of valid
interrupts.

Unfortunately in some cases you get legitimate invalid interrupts caused by
timing asynchronicity between the PCI bus and the APIC bus when disabling
interrupts and pulling other tricks.  In this case although the spurious
IRQs are not a problem our unhandled counters didn't clear and they act as
a slow running timebomb.  (This is effectively what the serial port/tty
problem that was fixed by clearing counters when registering a handler
showed up)

It's easy enough to add a second parameter - time.  This means that if we
see a regular stream of harmless spurious interrupts which are not harming
processing we don't go off and do something stupid like disable the IRQ
after a month of running.  OTOH lockups and performance killers show up a
lot more than 10/second

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Alan Cox <alan@redhat.com>
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>
2007-07-16 09:05:46 -07:00
Ravikiran G Thirumalai
e729aa16b1 Pad irq_desc to internode cacheline size
We noticed a drop in n/w performance due to the irq_desc being cacheline
aligned rather than internode aligned.  We see 50% of expected performance
when two e1000 nics local to two different nodes have consecutive irq
descriptors allocated, due to false sharing.

Note that this patch does away with cacheline padding for the UP case, as
it does not seem useful for UP configurations.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
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>
2007-05-08 11:15:09 -07:00
David Howells
77904fd64e [PATCH] FRV: Missing error defs
linux/irq.h uses EINVAL but does not #include linux/errno.h.  This results in
the compiler spitting out errors on some files.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-01 14:53:38 -08:00
Eric W. Biederman
9f0a5ba550 [PATCH] irq: Remove set_native_irq_info
This patch replaces all instances of "set_native_irq_info(irq, mask)"
with "irq_desc[irq].affinity = mask".  The latter form is clearer
uses fewer abstractions, and makes access to this field uniform
accross different architectures.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-26 10:34:07 -08:00
Andrew Morton
6168a702ab [PATCH] Declare init_irq_proc before we use it.
powerpc gets:

init/main.c: In function `do_basic_setup':
init/main.c:714: warning: implicit declaration of function `init_irq_proc'

but we cannot include linux/irq.h in generic code.

Fix it by moving the declaration into linux/interrupt.h instead.

And make sure all code that defines init_irq_proc() is including
linux/interrupt.h.

And nuke an ifdef-in-C

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-19 14:21:50 -08:00
Randy Dunlap
472900b8b0 [PATCH] IRQ kernel-doc fixes
Fix kernel-doc warnings in IRQ management.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:14:00 -08:00
Ingo Molnar
d7e25f3394 [PATCH] genirq: remove IRQ_DISABLED
Now that disable_irq() defaults to delayed-disable semantics, the IRQ_DISABLED
flag is not needed anymore.

Signed-off-by: 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>
2007-02-16 08:14:00 -08:00
Thomas Gleixner
771ee3b04e [PATCH] Add a function to handle interrupt affinity setting
Provide funtions to:
 - check, whether an interrupt can set the affinity
 - pin the interrupt to a given cpu

Necessary for the ability to setup clocksources more flexible (e.g.  use the
different HPET channels per CPU)

[akpm@osdl.org: alpha build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:56 -08:00
Thomas Gleixner
950f4427c2 [PATCH] Add irq flag to disable balancing for an interrupt
Add a flag so we can prevent the irq balancing of an interrupt.  Move the
bits, so we have room for more :)

Necessary for the ability to setup clocksources more flexible (e.g.  use the
different HPET channels per CPU)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:56 -08:00
Eric W. Biederman
5b912c108c msi: Kill the msi_desc array.
We need to be able to get from an irq number to a struct msi_desc.
The msi_desc array in msi.c had several short comings the big one was
that it could not be used outside of msi.c.  Using irq_data in struct
irq_desc almost worked except on some architectures irq_data needs to
be used for something else.

So this patch adds a msi_desc pointer to irq_desc, adds the appropriate
wrappers and changes all of the msi code to use them.

The dynamic_irq_init/cleanup code was tweaked to ensure the new
field is left in a well defined state.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07 15:50:08 -08:00
Ingo Molnar
145fc655a1 [PATCH] genirq: clean up irq-flow-type naming, fix
Re-add the set_irq_chip_and_handler() prototype, it's still widely used.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:37 -07:00
Ingo Molnar
a460e745e8 [PATCH] genirq: clean up irq-flow-type naming
Introduce desc->name and eliminate the handle_irq_name() hack.  Add
set_irq_chip_and_handler_name() to set the flow type and name at once.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:45 -07:00
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
David Howells
57a58a9435 IRQ: Typedef the IRQ flow handler function type
Typedef the IRQ flow handler function type.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 8e973fbdf5716b93a0a8c0365be33a31ca0fa351 commit)
2006-10-05 13:28:06 +01:00
Eric W. Biederman
1f80025e62 [PATCH] msi: simplify msi sanity checks by adding with generic irq code
Currently msi.c is doing sanity checks that make certain before an irq is
destroyed it has no more users.

By adding irq_has_action I can perform the test is a generic way, instead of
relying on a msi specific data structure.

By performing the core check in dynamic_irq_cleanup I ensure every user of
dynamic irqs has a test present and we don't free resources that are in use.

In msi.c this allows me to kill the attrib.state member of msi_desc and all of
the assciated code to maintain it.

To keep from freeing data structures when irq cleanup code is called to soon
changing dyanamic_irq_cleanup is insufficient because there are msi specific
data structures that are also not safe to free.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:29 -07:00
Eric W. Biederman
323a01c508 [PATCH] genirq: irq: remove msi hacks
Because of the nasty way that CONFIG_PCI_MSI was implemented we wound up with
set_irq_info and set_native_irq_info, with move_irq and move_native_irq.  Both
functions did the same thing but they were built and called under different
circumstances.  Now that the msi hacks are gone we can kill move_irq and
set_irq_info.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:28 -07:00
Eric W. Biederman
3a16d71362 [PATCH] genirq: irq: add a dynamic irq creation API
With the msi support comes a new concept in irq handling, irqs that are
created dynamically at run time.

Currently the msi code allocates irqs backwards.  First it allocates a
platform dependent routing value for an interrupt the ``vector'' and then it
figures out from the vector which irq you are on.

This msi backwards allocator suffers from two basic problems.  The allocator
suffers because it is trying to do something that is architecture specific in
a generic way making it brittle, inflexible, and tied to tightly to the
architecture implementation.  The alloctor also suffers from it's very
backwards nature as it has tied things together that should have no
dependencies.

To solve the basic dynamic irq allocation problem two new architecture
specific functions are added: create_irq and destroy_irq.

create_irq takes no input and returns an unused irq number, that won't be
reused until it is returned to the free poll with destroy_irq.  The irq then
can be used for any purpose although the only initial consumer is the msi
code.

destroy_irq takes an irq number allocated with create_irq and returns it to
the free pool.

Making this functionality per architecture increases the simplicity of the irq
allocation code and increases it's flexibility.

dynamic_irq_init() and dynamic_irq_cleanup() are added to automate the
irq_desc initializtion that should happen for dynamic irqs.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-04 07:55:27 -07:00