Commit Graph

34 Commits

Author SHA1 Message Date
Rafael J. Wysocki 17f4803420 genirq / PM: Add flag for shared NO_SUSPEND interrupt lines
It currently is required that all users of NO_SUSPEND interrupt
lines pass the IRQF_NO_SUSPEND flag when requesting the IRQ or the
WARN_ON_ONCE() in irq_pm_install_action() will trigger.  That is
done to warn about situations in which unprepared interrupt handlers
may be run unnecessarily for suspended devices and may attempt to
access those devices by mistake.  However, it may cause drivers
that have no technical reasons for using IRQF_NO_SUSPEND to set
that flag just because they happen to share the interrupt line
with something like a timer.

Moreover, the generic handling of wakeup interrupts introduced by
commit 9ce7a25849 (genirq: Simplify wakeup mechanism) only works
for IRQs without any NO_SUSPEND users, so the drivers of wakeup
devices needing to use shared NO_SUSPEND interrupt lines for
signaling system wakeup generally have to detect wakeup in their
interrupt handlers.  Thus if they happen to share an interrupt line
with a NO_SUSPEND user, they also need to request that their
interrupt handlers be run after suspend_device_irqs().

In both cases the reason for using IRQF_NO_SUSPEND is not because
the driver in question has a genuine need to run its interrupt
handler after suspend_device_irqs(), but because it happens to
share the line with some other NO_SUSPEND user.  Otherwise, the
driver would do without IRQF_NO_SUSPEND just fine.

To make it possible to specify that condition explicitly, introduce
a new IRQ action handler flag for shared IRQs, IRQF_COND_SUSPEND,
that, when set, will indicate to the IRQ core that the interrupt
user is generally fine with suspending the IRQ, but it also can
tolerate handler invocations after suspend_device_irqs() and, in
particular, it is capable of detecting system wakeup and triggering
it as appropriate from its interrupt handler.

That will allow us to work around a problem with a shared timer
interrupt line on at91 platforms.

Link: http://marc.info/?l=linux-kernel&m=142252777602084&w=2
Link: http://marc.info/?t=142252775300011&r=1&w=2
Link: https://lkml.org/lkml/2014/12/15/552
Reported-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
2015-03-04 21:42:19 +01:00
Linus Torvalds b528392669 ACPI and power management updates for 3.18-rc1
- Rework the handling of wakeup IRQs by the IRQ core such that
    all of them will be switched over to "wakeup" mode in
    suspend_device_irqs() and in that mode the first interrupt
    will abort system suspend in progress or wake up the system
    if already in suspend-to-idle (or equivalent) without executing
    any interrupt handlers.  Among other things that eliminates the
    wakeup-related motivation to use the IRQF_NO_SUSPEND interrupt
    flag with interrupts which don't really need it and should not
    use it (Thomas Gleixner and Rafael J Wysocki).
 
  - Switch over ACPI to handling wakeup interrupts with the help
    of the new mechanism introduced by the above IRQ core rework
    (Rafael J Wysocki).
 
  - Rework the core generic PM domains code to eliminate code that's
    not used, add DT support and add a generic mechanism by which
    devices can be added to PM domains automatically during
    enumeration (Ulf Hansson, Geert Uytterhoeven and Tomasz Figa).
 
  - Add debugfs-based mechanics for debugging generic PM domains
    (Maciej Matraszek).
 
  - ACPICA update to upstream version 20140828.  Included are updates
    related to the SRAT and GTDT tables and the _PSx methods are in
    the METHOD_NAME list now (Bob Moore and Hanjun Guo).
 
  - Add _OSI("Darwin") support to the ACPI core (unfortunately, that
    can't really be done in a straightforward way) to prevent
    Thunderbolt from being turned off on Apple systems after boot
    (or after resume from system suspend) and rework the ACPI Smart
    Battery Subsystem (SBS) driver to work correctly with Apple
    platforms (Matthew Garrett and Andreas Noever).
 
  - ACPI LPSS (Low-Power Subsystem) driver update cleaning up the
    code, adding support for 133MHz I2C source clock on Intel Baytrail
    to it and making it avoid using UART RTS override with Auto Flow
    Control (Heikki Krogerus).
 
  - ACPI backlight updates removing the video_set_use_native_backlight
    quirk which is not necessary any more, making the code check the
    list of output devices returned by the _DOD method to avoid
    creating acpi_video interfaces that won't work and adding a quirk
    for Lenovo Ideapad Z570 (Hans de Goede, Aaron Lu and Stepan Bujnak).
 
  - New Win8 ACPI OSI quirks for some Dell laptops (Edward Lin).
 
  - Assorted ACPI code cleanups (Fabian Frederick, Rasmus Villemoes,
    Sudip Mukherjee, Yijing Wang, and Zhang Rui).
 
  - cpufreq core updates and cleanups (Viresh Kumar, Preeti U Murthy,
    Rasmus Villemoes).
 
  - cpufreq driver updates: cpufreq-cpu0/cpufreq-dt (driver name
    change among other things), ppc-corenet, powernv (Viresh Kumar,
    Preeti U Murthy, Shilpasri G Bhat, Lucas Stach).
 
  - cpuidle support for DT-based idle states infrastructure, new
    ARM64 cpuidle driver, cpuidle core cleanups (Lorenzo Pieralisi,
    Rasmus Villemoes).
 
  - ARM big.LITTLE cpuidle driver updates: support for DT-based
    initialization and Exynos5800 compatible string (Lorenzo Pieralisi,
    Kevin Hilman).
 
  - Rework of the test_suspend kernel command line argument and
    a new trace event for console resume (Srinivas Pandruvada,
    Todd E Brandt).
 
  - Second attempt to optimize swsusp_free() (hibernation core) to
    make it avoid going through all PFNs which may be way too slow on
    some systems (Joerg Roedel).
 
  - devfreq updates (Paul Bolle, Punit Agrawal, Ãrjan Eide).
 
  - rockchip-io Adaptive Voltage Scaling (AVS) driver and AVS
    entry update in MAINTAINERS (Heiko Stübner, Kevin Hilman).
 
  - PM core fix related to clock management (Geert Uytterhoeven).
 
  - PM core's sysfs code cleanup (Johannes Berg).
 
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Merge tag 'pm+acpi-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "Features-wise, to me the most important this time is a rework of
  wakeup interrupts handling in the core that makes them work
  consistently across all of the available sleep states, including
  suspend-to-idle.  Many thanks to Thomas Gleixner for his help with
  this work.

  Second is an update of the generic PM domains code that has been in
  need of some care for quite a while.  Unused code is being removed, DT
  support is being added and domains are now going to be attached to
  devices in bus type code in analogy with the ACPI PM domain.  The
  majority of work here was done by Ulf Hansson who also has been the
  most active developer this time.

  Apart from this we have a traditional ACPICA update, this time to
  upstream version 20140828 and a few ACPI wakeup interrupts handling
  patches on top of the general rework mentioned above.  There also are
  several cpufreq commits including renaming the cpufreq-cpu0 driver to
  cpufreq-dt, as this is what implements generic DT-based cpufreq
  support, and a new DT-based idle states infrastructure for cpuidle.

  In addition to that, the ACPI LPSS driver is updated, ACPI support for
  Apple machines is improved, a few bugs are fixed and a few cleanups
  are made all over.

  Finally, the Adaptive Voltage Scaling (AVS) subsystem now has a tree
  maintained by Kevin Hilman that will be merged through the PM tree.

  Numbers-wise, the generic PM domains update takes the lead this time
  with 32 non-merge commits, second is cpufreq (15 commits) and the 3rd
  place goes to the wakeup interrupts handling rework (13 commits).

  Specifics:

   - Rework the handling of wakeup IRQs by the IRQ core such that all of
     them will be switched over to "wakeup" mode in suspend_device_irqs()
     and in that mode the first interrupt will abort system suspend in
     progress or wake up the system if already in suspend-to-idle (or
     equivalent) without executing any interrupt handlers.  Among other
     things that eliminates the wakeup-related motivation to use the
     IRQF_NO_SUSPEND interrupt flag with interrupts which don't really
     need it and should not use it (Thomas Gleixner and Rafael Wysocki)

   - Switch over ACPI to handling wakeup interrupts with the help of the
     new mechanism introduced by the above IRQ core rework (Rafael Wysocki)

   - Rework the core generic PM domains code to eliminate code that's
     not used, add DT support and add a generic mechanism by which
     devices can be added to PM domains automatically during enumeration
     (Ulf Hansson, Geert Uytterhoeven and Tomasz Figa).

   - Add debugfs-based mechanics for debugging generic PM domains
     (Maciej Matraszek).

   - ACPICA update to upstream version 20140828.  Included are updates
     related to the SRAT and GTDT tables and the _PSx methods are in the
     METHOD_NAME list now (Bob Moore and Hanjun Guo).

   - Add _OSI("Darwin") support to the ACPI core (unfortunately, that
     can't really be done in a straightforward way) to prevent
     Thunderbolt from being turned off on Apple systems after boot (or
     after resume from system suspend) and rework the ACPI Smart Battery
     Subsystem (SBS) driver to work correctly with Apple platforms
     (Matthew Garrett and Andreas Noever).

   - ACPI LPSS (Low-Power Subsystem) driver update cleaning up the code,
     adding support for 133MHz I2C source clock on Intel Baytrail to it
     and making it avoid using UART RTS override with Auto Flow Control
     (Heikki Krogerus).

   - ACPI backlight updates removing the video_set_use_native_backlight
     quirk which is not necessary any more, making the code check the
     list of output devices returned by the _DOD method to avoid
     creating acpi_video interfaces that won't work and adding a quirk
     for Lenovo Ideapad Z570 (Hans de Goede, Aaron Lu and Stepan Bujnak)

   - New Win8 ACPI OSI quirks for some Dell laptops (Edward Lin)

   - Assorted ACPI code cleanups (Fabian Frederick, Rasmus Villemoes,
     Sudip Mukherjee, Yijing Wang, and Zhang Rui)

   - cpufreq core updates and cleanups (Viresh Kumar, Preeti U Murthy,
     Rasmus Villemoes)

   - cpufreq driver updates: cpufreq-cpu0/cpufreq-dt (driver name change
     among other things), ppc-corenet, powernv (Viresh Kumar, Preeti U
     Murthy, Shilpasri G Bhat, Lucas Stach)

   - cpuidle support for DT-based idle states infrastructure, new ARM64
     cpuidle driver, cpuidle core cleanups (Lorenzo Pieralisi, Rasmus
     Villemoes)

   - ARM big.LITTLE cpuidle driver updates: support for DT-based
     initialization and Exynos5800 compatible string (Lorenzo Pieralisi,
     Kevin Hilman)

   - Rework of the test_suspend kernel command line argument and a new
     trace event for console resume (Srinivas Pandruvada, Todd E Brandt)

   - Second attempt to optimize swsusp_free() (hibernation core) to make
     it avoid going through all PFNs which may be way too slow on some
     systems (Joerg Roedel)

   - devfreq updates (Paul Bolle, Punit Agrawal, Ãrjan Eide).

   - rockchip-io Adaptive Voltage Scaling (AVS) driver and AVS entry
     update in MAINTAINERS (Heiko Stübner, Kevin Hilman)

   - PM core fix related to clock management (Geert Uytterhoeven)

   - PM core's sysfs code cleanup (Johannes Berg)"

* tag 'pm+acpi-3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (105 commits)
  ACPI / fan: printk replacement
  PM / clk: Fix crash in clocks management code if !CONFIG_PM_RUNTIME
  PM / Domains: Rename cpu_data to cpuidle_data
  cpufreq: cpufreq-dt: fix potential double put of cpu OF node
  cpufreq: cpu0: rename driver and internals to 'cpufreq_dt'
  PM / hibernate: Iterate over set bits instead of PFNs in swsusp_free()
  cpufreq: ppc-corenet: remove duplicate update of cpu_data
  ACPI / sleep: Rework the handling of ACPI GPE wakeup from suspend-to-idle
  PM / sleep: Rename platform suspend/resume functions in suspend.c
  PM / sleep: Export dpm_suspend_late/noirq() and dpm_resume_early/noirq()
  ACPICA: Introduce acpi_enable_all_wakeup_gpes()
  ACPICA: Clear all non-wakeup GPEs in acpi_hw_enable_wakeup_gpe_block()
  ACPI / video: check _DOD list when creating backlight devices
  PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h
  cpufreq: Replace strnicmp with strncasecmp
  cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec
  cpufreq: powernv: Set the pstate of the last hotplugged out cpu in policy->cpus to minimum
  cpufreq: Allow stop CPU callback to be used by all cpufreq drivers
  PM / devfreq: exynos: Enable building exynos PPMU as module
  PM / devfreq: Export helper functions for drivers
  ...
2014-10-09 16:07:43 -04:00
Marc Zyngier 76ba59f836 genirq: Add irq_domain-aware core IRQ handler
Calling irq_find_mapping from outside a irq_{enter,exit} section is
unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled:
If coming from the idle state, the rcu_read_lock call in irq_find_mapping
will generate an unpleasant warning:

<quote>
===============================
[ INFO: suspicious RCU usage. ]
3.16.0-rc1+ #135 Not tainted
-------------------------------
include/linux/rcupdate.h:871 rcu_read_lock() used illegally while idle!

other info that might help us debug this:

RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
1 lock held by swapper/0/0:
 #0:  (rcu_read_lock){......}, at: [<ffffffc00010206c>]
irq_find_mapping+0x4c/0x198
</quote>

As this issue is fairly widespread and involves at least three
different architectures, a possible solution is to add a new
handle_domain_irq entry point into the generic IRQ code that
the interrupt controller code can call.

This new function takes an irq_domain, and calls into irq_find_domain
inside the irq_{enter,exit} block. An additional "lookup" parameter is
used to allow non-domain architecture code to be replaced by this as well.

Interrupt controllers can then be updated to use the new mechanism.

This code is sitting behind a new CONFIG_HANDLE_DOMAIN_IRQ, as not all
architectures implement set_irq_regs (yes, mn10300, I'm looking at you...).

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1409047421-27649-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-09-03 12:57:27 +00:00
Thomas Gleixner cab303be91 genirq: Add sanity checks for PM options on shared interrupt lines
Account the IRQF_NO_SUSPEND and IRQF_RESUME_EARLY actions on shared
interrupt lines and yell loudly if there is a mismatch.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-09-01 13:48:05 +02:00
Thomas Gleixner 1e77d0a1ed genirq: Sanitize spurious interrupt detection of threaded irqs
Till reported that the spurious interrupt detection of threaded
interrupts is broken in two ways:

- note_interrupt() is called for each action thread of a shared
  interrupt line. That's wrong as we are only interested whether none
  of the device drivers felt responsible for the interrupt, but by
  calling multiple times for a single interrupt line we account
  IRQ_NONE even if one of the drivers felt responsible.

- note_interrupt() when called from the thread handler is not
  serialized. That leaves the members of irq_desc which are used for
  the spurious detection unprotected.

To solve this we need to defer the spurious detection of a threaded
interrupt to the next hardware interrupt context where we have
implicit serialization.

If note_interrupt is called with action_ret == IRQ_WAKE_THREAD, we
check whether the previous interrupt requested a deferred check. If
not, we request a deferred check for the next hardware interrupt and
return. 

If set, we check whether one of the interrupt threads signaled
success. Depending on this information we feed the result into the
spurious detector.

If one primary handler of a shared interrupt returns IRQ_HANDLED we
disable the deferred check of irq threads on the same line, as we have
found at least one device driver who cared.

Reported-by: Till Straumann <strauman@slac.stanford.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Austin Schuh <austin@peloton-tech.com>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-can@vger.kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1303071450130.22263@ionos
2014-05-03 23:15:39 +02:00
Vinayak Kale 7f4a8e7b19 genirq: Add an accessor for IRQ_PER_CPU flag
This patch adds an accessor function for IRQ_PER_CPU flag.
The accessor function is useful to determine whether an IRQ is percpu or not.

This patch is based on an older patch posted by Chris Smith here [1].
There is a minor change w.r.t. Chris's original patch: The accessor function
is renamed as 'irq_is_percpu' instead of 'irq_is_per_cpu'.

[1]: http://lkml.indiana.edu/hypermail/linux/kernel/1207.3/02955.html

Signed-off-by: Chris Smith <chris.smith@st.com>
Signed-off-by: Vinayak Kale <vkale@apm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19 17:43:04 +00:00
Martin Schwidefsky 0244ad004a Remove GENERIC_HARDIRQ config option
After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-09-13 15:09:52 +02:00
Thomas Gleixner 293a7a0a16 genirq: Provide means to retrigger parent
Attempts to retrigger nested threaded IRQs currently fail because they
have no primary handler. In order to support retrigger of nested
IRQs, the parent IRQ needs to be retriggered.

To fix, when an IRQ needs to be resent, if the interrupt has a parent
IRQ and runs in the context of the parent IRQ, then resend the parent.

Also, handle_nested_irq() needs to clear the replay flag like the
other handlers, otherwise check_irq_resend() will set it and it will
never be cleared.  Without clearing, it results in the first resend
working fine, but check_irq_resend() returning early on subsequent
resends because the replay flag is still set.

Problem discovered on ARM/OMAP platforms where a nested IRQ that's
also a wakeup IRQ happens late in suspend and needed to be retriggered
during the resume process.

[khilman@ti.com: changelog edits, clear IRQS_REPLAY in handle_nested_irq()]

Reported-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1350425269-11489-1-git-send-email-khilman@deeprootsystems.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2012-11-01 12:11:31 +01:00
Linus Torvalds 99dbb1632f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull the trivial tree from Jiri Kosina:
 "Tiny usual fixes all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
  doc: fix old config name of kprobetrace
  fs/fs-writeback.c: cleanup riteback_sb_inodes kerneldoc
  btrfs: fix the commment for the action flags in delayed-ref.h
  btrfs: fix trivial typo for the comment of BTRFS_FREE_INO_OBJECTID
  vfs: fix kerneldoc for generic_fh_to_parent()
  treewide: fix comment/printk/variable typos
  ipr: fix small coding style issues
  doc: fix broken utf8 encoding
  nfs: comment fix
  platform/x86: fix asus_laptop.wled_type module parameter
  mfd: printk/comment fixes
  doc: getdelays.c: remember to close() socket on error in create_nl_socket()
  doc: aliasing-test: close fd on write error
  mmc: fix comment typos
  dma: fix comments
  spi: fix comment/printk typos in spi
  Coccinelle: fix typo in memdup_user.cocci
  tmiofb: missing NULL pointer checks
  tools: perf: Fix typo in tools/perf
  tools/testing: fix comment / output typos
  ...
2012-10-01 09:06:36 -07:00
Paul Gortmaker ef706fb556 irqdesc: delete now orphaned references to timer_rand_state
In commit c5857ccf29 ("random: remove rand_initialize_irq()")
the timer_rand_state was removed from struct irq_desc.  Hence
we can also remove the forward declaration of it and the kernel
doc information now too.

Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-08-15 09:58:46 +02:00
Theodore Ts'o c5857ccf29 random: remove rand_initialize_irq()
With the new interrupt sampling system, we are no longer using the
timer_rand_state structure in the irq descriptor, so we can stop
initializing it now.

[ Merged in fixes from Sedat to find some last missing references to
  rand_initialize_irq() ]

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
2012-07-19 10:38:32 -04:00
Paul Gortmaker ec53cf23c0 irq: don't put module.h into irq.h for tracking irqgen modules.
Recent commit "irq: Track the  owner of irq descriptor" in
commit ID b6873807a7 placed module.h into linux/irq.h
but we are trying to limit module.h inclusion to just C files
that really need it, due to its size and number of children
includes.  This targets just reversing that include.

Add in the basic "struct module" since that is all we really need
to ensure things compile.  In theory, b687380 should have added the
module.h include to the irqdesc.h header as well, but the implicit
module.h everywhere presence masked this from showing up.  So give
it the "struct module" as well.

As for the C files, irqdesc.c is only using THIS_MODULE, so it
does not need module.h - give it export.h instead.  The C file
irq/manage.c is now (as of b687380) using try_module_get and
module_put and so it needs module.h (which it already has).

Also convert the irq_alloc_descs variants to macros, since all
they really do is is call the __irq_alloc_descs primitive.
This avoids including export.h and no debug info is lost.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:35 -04:00
Marc Zyngier 31d9d9b6d8 genirq: Add support for per-cpu dev_id interrupts
The ARM GIC interrupt controller offers per CPU interrupts (PPIs),
which are usually used to connect local timers to each core. Each CPU
has its own private interface to the GIC, and only sees the PPIs that
are directly connect to it.

While these timers are separate devices and have a separate interrupt
line to a core, they all use the same IRQ number.

For these devices, request_irq() is not the right API as it assumes
that an IRQ number is visible by a number of CPUs (through the
affinity setting), but makes it very awkward to express that an IRQ
number can be handled by all CPUs, and yet be a different interrupt
line on each CPU, requiring a different dev_id cookie to be passed
back to the handler.

The *_percpu_irq() functions is designed to overcome these
limitations, by providing a per-cpu dev_id vector:

int request_percpu_irq(unsigned int irq, irq_handler_t handler,
		   const char *devname, void __percpu *percpu_dev_id);
void free_percpu_irq(unsigned int, void __percpu *);
int setup_percpu_irq(unsigned int irq, struct irqaction *new);
void remove_percpu_irq(unsigned int irq, struct irqaction *act);
void enable_percpu_irq(unsigned int irq);
void disable_percpu_irq(unsigned int irq);

The API has a number of limitations:
- no interrupt sharing
- no threading
- common handler across all the CPUs

Once the interrupt is requested using setup_percpu_irq() or
request_percpu_irq(), it must be enabled by each core that wishes its
local interrupt to be delivered.

Based on an initial patch by Thomas Gleixner.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1316793788-14500-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-10-03 15:35:26 +02:00
Sebastian Andrzej Siewior b6873807a7 irq: Track the owner of irq descriptor
Interrupt descriptors can be allocated from modules. The interrupts
are used by other modules, but we have no refcount on the module which
provides the interrupts and there is no way to establish one on the
device level as the interrupt using module is agnostic to the fact
that the interrupt is provided by a module rather than by some builtin
interrupt controller.

To prevent removal of the interrupt providing module, we can track the
owner of the interrupt descriptor, which also provides the relevant
irq chip functions in the irq descriptor.

request/setup_irq() can now acquire a refcount on the owner module to
prevent unloading. free_irq() drops the refcount.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Link: http://lkml.kernel.org/r/20110711101731.GA13804@Chamillionaire.breakpoint.cc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-07-28 11:23:21 +02:00
Thomas Gleixner fe12bc2c99 genirq: Uninline and sanity check generic_handle_irq()
generic_handle_irq() is missing a NULL pointer check for the result of
irq_to_desc. This was a not a big problem, but we want to expose it to
drivers, so we better have sanity checks in place. Add a return value
as well, which indicates that the irq number was valid and the handler
was invoked.

Based on the pure code move from Jonathan Cameron.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
2011-05-18 14:59:08 +02:00
Geert Uytterhoeven 770767787c genirq: irq_desc: Document preflow_handler and affinity_hint
[ tglx: Filled in the FIXME place holders ]

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/%3C1302426113-13808-2-git-send-email-geert%40linux-m68k.org%3E
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-04-23 15:56:24 +02:00
Geert Uytterhoeven 0911f124bf genirq: Forgotten updates/deletions after removal of compat code
commit 0c6f8a8b91 ("genirq: Remove compat code")
removed the compat code, but forgot to update some references in comments and
delete some of its documentation.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: http://lkml.kernel.org/r/%3C1302426113-13808-1-git-send-email-geert%40linux-m68k.org%3E
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-04-23 15:56:23 +02:00
Thomas Gleixner 0c6f8a8b91 genirq: Remove compat code
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-29 14:48:19 +02:00
Thomas Gleixner a2e8461a2c genirq: Provide locked setter for chip, handler, name
Some irq_set_type() callbacks need to change the chip and the handler
when the trigger mode changes. We have already a (misnomed) setter
function for the handler which can be called from irq_set_type().

Provide one which allows to set chip and name as well. Put the
misnomed function under the COMPAT switch and provide a replacement.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-23 20:22:06 +01:00
Thomas Gleixner d3e17deb17 genirq: Provide a lockdep helper
Some irq chips need to call genirq functions for nested chips from
their callbacks. That upsets lockdep. So they need to set a different
lock class for those nested chips. Provide a helper function to avoid
open access to irq_desc.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-23 20:22:06 +01:00
Thomas Gleixner 3b90389128 genirq; Remove the last leftovers of the old sparse irq code
All users converted. Get rid of it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-23 20:22:06 +01:00
Thomas Gleixner d9936bb395 genirq: Add desc->irq_data accessor
We have accessors for all fields in irq_data based on irq_desc, but
not for irq_data itself.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-11 14:15:35 +01:00
Thomas Gleixner b5faba21a6 genirq: Prepare the handling of shared oneshot interrupts
For level type interrupts we need to track how many threads are on
flight to avoid useless interrupt storms when not all thread handlers
have finished yet. Keep track of the woken threads and only unmask
when there are no more threads in flight.

Yes, I'm lazy and using a bitfield. But not only because I'm lazy, the
main reason is that it's way simpler than using a refcount. A refcount
based solution would need to keep track of various things like
crashing the irq thread, spurious interrupts coming in,
disables/enables, free_irq() and some more. The bitfield keeps the
tracking simple and makes things just work. It's also nicely confined
to the thread code pathes and does not require additional checks all
over the place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110223234956.388095876@linutronix.de>
2011-02-25 20:24:21 +01:00
Thomas Gleixner 781295762d genirq: Add preflow handler support
sparc64 needs to call a preflow handler on certain interrupts befor
calling the action chain. Integrate it into handle_fasteoi_irq. Must
be enabled via CONFIG_IRQ_FASTEOI_PREFLOW. No impact when disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David S. Miller <davem@davemloft.net>
2011-02-19 12:58:24 +01:00
Thomas Gleixner a6967caf00 genirq: Remove desc->status when GENERIC_HARDIRQS_NO_COMPAT=y
If everything uses the right accessors, then enabling
GENERIC_HARDIRQS_NO_COMPAT should just work. If not it will tell you.

Don't be lazy and use the trick which I use in the core code!

git grep status_use_accessors

will unearth it in a split second. Offenders are tracked down and not
slapped with stinking trouts. This time we use frozen shark for a
better educational value.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:22 +01:00
Thomas Gleixner 91c4991781 genirq: Add state field to irq_data
Some chip implementations need to access certain status flags. With
sparse irqs that requires a lookup of the irq descriptor. Add a state
field which contains such flags.

Name it in a way which will make coders happy to access it with the
proper accessor functions. And it's easy to grep for.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:18 +01:00
Thomas Gleixner dbec07bac6 genirq: Add internal state field to irq_desc
That field will contain internal state information which is not going
to be exposed to anything outside the core code - except via accessor
functions. I'm tired of everyone fiddling in irq_desc.status.

core_internal_state__do_not_mess_with_it is clear enough, annoying to
type and easy to grep for. Offenders will be tracked down and slapped
with stinking trouts.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-02-19 12:58:14 +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
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
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 10ba1e0eee genirq: Remove irq_2_iommu
irq_2_iommu is now in the x86 code where it belongs. Remove all
leftovers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-12 16:53:43 +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