The new VMD device driver needs to iterate over a list of
"demultiplexing" interrupts. Protecting that list with a lock is not
possible because the list is also required in code pathes which hold
irq descriptor lock. Therefor the demultiplexing interrupt handler
would create a lock inversion scenario if it calls a demux handler
with the list protection lock held.
A solution for this is to free the irq descriptor via RCU, so the
list can be walked with rcu read lock held.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Keith Busch <keith.busch@intel.com>
Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.
Remove the argument.
Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
MSI descriptors are per-irq instead of per irqchip, so move it into
struct irq_common_data.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433145945-789-35-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Handler data (handler_data) is per-irq instead of per irqchip, so move
it into struct irq_common_data.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433145945-789-13-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Avoid the lookup of irq_desc and use the same mechanism for
hierarchical and flat irqdomains.
Based-on-a-patch-from: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we have a reference to irq_desc already, there is no point to do
another lookup.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/20150802203609.638130301@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When a cpu goes up some architectures (e.g. x86) have to walk the irq
space to set up the vector space for the cpu. While this needs extra
protection at the architecture level we can avoid a few race
conditions by preventing the concurrent allocation/free of irq
descriptors and the associated data.
When a cpu goes down it moves the interrupts which are targeted to
this cpu away by reassigning the affinities. While this happens
interrupts can be allocated and freed, which opens a can of race
conditions in the code which reassignes the affinities because
interrupt descriptors might be freed underneath.
Example:
CPU1 CPU2
cpu_up/down
irq_desc = irq_to_desc(irq);
remove_from_radix_tree(desc);
raw_spin_lock(&desc->lock);
free(desc);
We could protect the irq descriptors with RCU, but that would require
a full tree change of all accesses to interrupt descriptors. But
fortunately these kind of race conditions are rather limited to a few
things like cpu hotplug. The normal setup/teardown is very well
serialized. So the simpler and obvious solution is:
Prevent allocation and freeing of interrupt descriptors accross cpu
hotplug.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: xiao jin <jin.xiao@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Link: http://lkml.kernel.org/r/20150705171102.063519515@linutronix.de
The main use case for the exisiting __irq_set_*_locked() inlines is to
replace the handler [,chip and name] of an interrupt from a region
which has the irq descriptor lock held, e.g. from the irq_set_type()
callback. The first argument is the irq number, so the functions need
so perform a pointless lookup of the interrupt descriptor for those
cases which have the irq_data pointer handy.
Provide new functions which take an irq_data pointer instead of the
interrupt number, so the lookup of the interrupt descriptor can be
avoided.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Conflicts:
include/linux/irqdesc.h
Introduce helper irq_desc_get_irq() to retrieve the irq number from
the irq descriptor.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433391238-19471-17-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Seems we have little chance to move irqdesc.h from include/linux/ into
kernel/irq/, so remove the outdated comments.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433391238-19471-2-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
With the introduction of hierarchy irqdomain, struct irq_data becomes
per-chip instead of per-irq and there may be multiple irq_datas
associated with the same irq. Some per-irq data stored in struct
irq_data now may get duplicated into multiple irq_datas, and causes
inconsistent view.
So introduce struct irq_common_data to host per-irq common data and to
achieve consistent view among irq_chips.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433145945-789-4-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
For irq associated with hierarchy irqdomains, there will be multiple
irq_datas for one irq_desc. So enhance irq_data_to_desc() to support
hierarchy irqdomain. Also export irq_data_to_desc() as an inline
function for later reuse.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1433145945-789-2-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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>
- 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
...
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>
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>
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
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>
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>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
