for_each_active_irq() iterates the sparse irq allocation bitmap. The caller
must hold sparse_irq_lock. Several code pathes expect that an active bit in
the sparse bitmap also has a valid interrupt descriptor.
Unfortunately that's not true. The (de)allocation is a two step process,
which holds the sparse_irq_lock only across the queue/remove from the radix
tree and the set/clear in the allocation bitmap.
If a iteration locks sparse_irq_lock between the two steps, then it might
see an active bit but the corresponding irq descriptor is NULL. If that is
dereferenced unconditionally, then the kernel oopses. Of course, all
iterator sites could be audited and fixed, but....
There is no reason why the sparse_irq_lock needs to be dropped between the
two steps, in fact the code becomes simpler when the mutex is held across
both and the semantics become more straight forward, so future problems of
missing NULL pointer checks in the iteration are avoided and all existing
sites are fixed in one go.
Expand the lock held sections so both operations are covered and the bitmap
and the radixtree are in sync.
Fixes: a05a900a51 ("genirq: Make sparse_lock a mutex")
Reported-and-tested-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Pull irq fixes from Thomas Gleixner:
- A few fixes mopping up the fallout of the big irq overhaul
- Move the interrupt resource management logic out of the spin locked,
irq disabled region to avoid unnecessary restrictions of the resource
callbacks
- Preparation for reworking the per cpu irq request function.
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqdomain: Allow ACPI device nodes to be used as irqdomain identifiers
genirq/debugfs: Remove redundant NULL pointer check
genirq: Allow to pass the IRQF_TIMER flag with percpu irq request
genirq/timings: Move free timings out of spinlocked region
genirq: Move irq resource handling out of spinlocked region
genirq: Add mutex to irq desc to serialize request/free_irq()
genirq: Move bus locking into __setup_irq()
genirq: Force inlining of __irq_startup_managed to prevent build failure
genirq/debugfs: Fix build for !CONFIG_IRQ_DOMAIN
The irq_request/release_resources() callbacks ar currently invoked under
desc->lock with interrupts disabled. This is a source of problems on RT and
conceptually not required.
Add a seperate mutex to struct irq_desc which allows to serialize
request/free_irq(), which can be used to move the resource functions out of
the desc->lock held region.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Julia Cartwright <julia@ni.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Doug Anderson <dianders@chromium.org>
Cc: linux-rockchip@lists.infradead.org
Cc: John Keeping <john@metanate.com>
Cc: linux-gpio@vger.kernel.org
Link: http://lkml.kernel.org/r/20170629214344.039220922@linutronix.de
around. Highlights include:
- Conversion of a bunch of security documentation into RST
- The conversion of the remaining DocBook templates by The Amazing
Mauro Machine. We can now drop the entire DocBook build chain.
- The usual collection of fixes and minor updates.
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Merge tag 'docs-4.13' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"There has been a fair amount of activity in the docs tree this time
around. Highlights include:
- Conversion of a bunch of security documentation into RST
- The conversion of the remaining DocBook templates by The Amazing
Mauro Machine. We can now drop the entire DocBook build chain.
- The usual collection of fixes and minor updates"
* tag 'docs-4.13' of git://git.lwn.net/linux: (90 commits)
scripts/kernel-doc: handle DECLARE_HASHTABLE
Documentation: atomic_ops.txt is core-api/atomic_ops.rst
Docs: clean up some DocBook loose ends
Make the main documentation title less Geocities
Docs: Use kernel-figure in vidioc-g-selection.rst
Docs: fix table problems in ras.rst
Docs: Fix breakage with Sphinx 1.5 and upper
Docs: Include the Latex "ifthen" package
doc/kokr/howto: Only send regression fixes after -rc1
docs-rst: fix broken links to dynamic-debug-howto in kernel-parameters
doc: Document suitability of IBM Verse for kernel development
Doc: fix a markup error in coding-style.rst
docs: driver-api: i2c: remove some outdated information
Documentation: DMA API: fix a typo in a function name
Docs: Insert missing space to separate link from text
doc/ko_KR/memory-barriers: Update control-dependencies example
Documentation, kbuild: fix typo "minimun" -> "minimum"
docs: Fix some formatting issues in request-key.rst
doc: ReSTify keys-trusted-encrypted.txt
doc: ReSTify keys-request-key.txt
...
There is currently no way to evaluate the effective affinity mask of a
given interrupt. Many irq chips allow only a single target CPU or a subset
of CPUs in the affinity mask.
Updating the mask at the time of setting the affinity to the subset would
be counterproductive because information for cpu hotplug about assigned
interrupt affinities gets lost. On CPU hotplug it's also pointless to force
migrate an interrupt, which is not targeted at the CPU effectively. But
currently the information is not available.
Provide a seperate mask to be updated by the irq_chip->irq_set_affinity()
implementations. Implement the read only proc files so the user can see the
effective mask as well w/o trying to deduce it from /proc/interrupts.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.247834245@linutronix.de
All callers hand in GPF_KERNEL. No point to have an extra argument for
that.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.082544752@linutronix.de
Debugging (hierarchical) interupt domains is tedious as there is no
information about the hierarchy and no information about states of
interrupts in the various domain levels.
Add a debugfs directory 'irq' and subdirectories 'domains' and 'irqs'.
The domains directory contains the domain files. The content is information
about the domain. If the domain is part of a hierarchy then the parent
domains are printed as well.
# ls /sys/kernel/debug/irq/domains/
default INTEL-IR-2 INTEL-IR-MSI-2 IO-APIC-IR-2 PCI-MSI
DMAR-MSI INTEL-IR-3 INTEL-IR-MSI-3 IO-APIC-IR-3 unknown-1
INTEL-IR-0 INTEL-IR-MSI-0 IO-APIC-IR-0 IO-APIC-IR-4 VECTOR
INTEL-IR-1 INTEL-IR-MSI-1 IO-APIC-IR-1 PCI-HT
# cat /sys/kernel/debug/irq/domains/VECTOR
name: VECTOR
size: 0
mapped: 216
flags: 0x00000041
# cat /sys/kernel/debug/irq/domains/IO-APIC-IR-0
name: IO-APIC-IR-0
size: 24
mapped: 19
flags: 0x00000041
parent: INTEL-IR-3
name: INTEL-IR-3
size: 65536
mapped: 167
flags: 0x00000041
parent: VECTOR
name: VECTOR
size: 0
mapped: 216
flags: 0x00000041
Unfortunately there is no per cpu information about the VECTOR domain (yet).
The irqs directory contains detailed information about mapped interrupts.
# cat /sys/kernel/debug/irq/irqs/3
handler: handle_edge_irq
status: 0x00004000
istate: 0x00000000
ddepth: 1
wdepth: 0
dstate: 0x01018000
IRQD_IRQ_DISABLED
IRQD_SINGLE_TARGET
IRQD_MOVE_PCNTXT
node: 0
affinity: 0-143
effectiv: 0
pending:
domain: IO-APIC-IR-0
hwirq: 0x3
chip: IR-IO-APIC
flags: 0x10
IRQCHIP_SKIP_SET_WAKE
parent:
domain: INTEL-IR-3
hwirq: 0x20000
chip: INTEL-IR
flags: 0x0
parent:
domain: VECTOR
hwirq: 0x3
chip: APIC
flags: 0x0
This was developed to simplify the debugging of the managed affinity
changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.537566163@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The printk in early_irq_init() is cryptic and badly formatted:
NR_IRQS:33024 nr_irqs:968 16
The last number is the number of preallocated interrupts, so add a prefix
to it:
NR_IRQS: 33024, nr_irqs: 968, preallocated irqs: 16
Cleanup the formatting for better readability as well.
Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494318849-6733-1-git-send-email-vincent.legoll@gmail.com
This book got converted from DocBook. Update its references to
point to the current location.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Information about interrupts is exposed via /proc/interrupts, but the
format of that file has changed over kernel versions and differs across
architectures. It also has varying column numbers depending on hardware.
That all makes it hard for tools to parse.
To solve this, expose the information through sysfs so each irq attribute
is in a separate file in a consistent, machine parsable way.
This feature is only available when both CONFIG_SPARSE_IRQ and
CONFIG_SYSFS are enabled.
Examples:
/sys/kernel/irq/18/actions: i801_smbus,ehci_hcd:usb1,uhci_hcd:usb7
/sys/kernel/irq/18/chip_name: IR-IO-APIC
/sys/kernel/irq/18/hwirq: 18
/sys/kernel/irq/18/name: fasteoi
/sys/kernel/irq/18/per_cpu_count: 0,0
/sys/kernel/irq/18/type: level
/sys/kernel/irq/25/actions: ahci0
/sys/kernel/irq/25/chip_name: IR-PCI-MSI
/sys/kernel/irq/25/hwirq: 512000
/sys/kernel/irq/25/name: edge
/sys/kernel/irq/25/per_cpu_count: 29036,0
/sys/kernel/irq/25/type: edge
[ tglx: Moved kobject_del() under sparse_irq_lock, massaged code comments
and changelog ]
Signed-off-by: Craig Gallek <kraig@google.com>
Cc: David Decotigny <decot@google.com>
Link: http://lkml.kernel.org/r/1473783291-122873-1-git-send-email-kraigatgoog@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Use the affinity hint in the irqdesc allocator. The hint is used to determine
the node for the allocation and to set the affinity of the interrupt.
If multiple interrupts are allocated (multi-MSI) then the allocator iterates
over the cpumask and for each set cpu it allocates on their node and sets the
initial affinity to that cpu.
If a single interrupt is allocated (MSI-X) then the allocator uses the first
cpu in the mask to compute the allocation node and uses the mask for the
initial affinity setting.
Interrupts set up this way are marked with the AFFINITY_MANAGED flag to
prevent userspace from messing with their affinity settings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: linux-block@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: axboe@fb.com
Cc: agordeev@redhat.com
Link: http://lkml.kernel.org/r/1467621574-8277-5-git-send-email-hch@lst.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In order to prepare the genirq layer for the concept of partitionned
percpu interrupts, let's allow an affinity to be associated with
such an interrupt. We introduce:
- irq_set_percpu_devid_partition: flag an interrupt as a percpu-devid
interrupt, and associate it with an affinity
- irq_get_percpu_devid_partition: allow the affinity of that interrupt
to be retrieved.
This will allow a driver to discover which CPUs the per-cpu interrupt
can actually fire on.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/1460365075-7316-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we isolate CPUs, then we don't want random device interrupts on them. Even
w/o the user space irq balancer enabled we can end up with irqs on non boot
cpus and chasing newly requested interrupts is a tedious task.
Allow to restrict the default irq affinity mask.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1602031948190.25254@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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>
Irq affinity mask 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>
Link: http://lkml.kernel.org/r/1433303281-27688-1-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>
NUMA node information is per-irq instead of per-irqchip, so move it into
struct irq_common_data. Also use CONFIG_NUMA to guard irq_common_data.node.
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>
Link: http://lkml.kernel.org/r/1433145945-789-8-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The first parameter 'irq' is never used by
kstat_incr_irqs_this_cpu(). Remove it.
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>
Link: http://lkml.kernel.org/r/1433391238-19471-16-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Introduce helper function irq_data_get_node() and variants thereof to
hide struct irq_data implementation details.
Convert the core code to use them.
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>
Link: http://lkml.kernel.org/r/1433145945-789-5-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>
The return type of kstat_irqs_usr() is unsigned int and kstat_irqs() also
returns unsigned int so sum should be unsigned int here as well.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Link: http://lkml.kernel.org/r/1430642951-23964-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kstat_irqs is unsigned int and the return type of kstat_irqs() is also
unsigned int so sum should be unsigned int as well even if the result
is correct due to automatic type conversion.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Link: http://lkml.kernel.org/r/1430642930-23929-1-git-send-email-hofrat@osadl.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since the rework of the sparse interrupt code to actually free the
unused interrupt descriptors there exists a race between the /proc
interfaces to the irq subsystem and the code which frees the interrupt
descriptor.
CPU0 CPU1
show_interrupts()
desc = irq_to_desc(X);
free_desc(desc)
remove_from_radix_tree();
kfree(desc);
raw_spinlock_irq(&desc->lock);
/proc/interrupts is the only interface which can actively corrupt
kernel memory via the lock access. /proc/stat can only read from freed
memory. Extremly hard to trigger, but possible.
The interfaces in /proc/irq/N/ are not affected by this because the
removal of the proc file is serialized in procfs against concurrent
readers/writers. The removal happens before the descriptor is freed.
For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue
as the descriptor is never freed. It's merely cleared out with the irq
descriptor lock held. So any concurrent proc access will either see
the old correct value or the cleared out ones.
Protect the lookup and access to the irq descriptor in
show_interrupts() with the sparse_irq_lock.
Provide kstat_irqs_usr() which is protecting the lookup and access
with sparse_irq_lock and switch /proc/stat to use it.
Document the existing kstat_irqs interfaces so it's clear that the
caller needs to take care about protection. The users of these
interfaces are either not affected due to SPARSE_IRQ=n or already
protected against removal.
Fixes: 1f5a5b87f7 "genirq: Implement a sane sparse_irq allocator"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
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>
irq_free_hwirqs() always calls irq_free_descs() with a cnt == 0
which makes it a no-op since the interrupt count to free is
decremented in itself.
Fixes: 7b6ef12625
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1404167084-8070-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
No more users. Get rid of the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140507154341.012847637@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Create a new interface and confine it with a config switch which makes
clear that this is just legacy support and not to be used for new code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140507154340.574437049@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
No more users. And it's not going to come back. If you need
hotplugable irq chips, use irq domains.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-and-acked-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140507154340.302183048@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We want to get rid of the public interface.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140507154340.061990194@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Not really the solution to the problem, but at least it confines the
mess in the core code and allows to get rid of the create/destroy_irq
variants from hell, i.e. 3 implementations with different semantics
plus the x86 specific variants __create_irqs and create_irq_nr
which have been invented in another circle of hell.
x86 : x86 should be converted to irq domains and I'm deliberately
making it impossible to do the multi-vector MSI support by
adding more crap to the current mess. It's not that hard to do
and I'm really tired of the trainwrecks which have been invented
by baindaid engineering so far. Any attempt to do multi-vector
MSI or ioapic hotplug without converting to irq domains is NAKed
hereby.
tile: Might use irq domains as well, but it has a very limited
interrupt space, so handling it via this functionality might be
the right thing to do even in the long run.
ia64: That's an hopeless case, as I doubt that anyone has the stomach
to rewrite the homebrewn dynamic allocation facilities. I stared
at it for a couple of hours and gave up. The create/destroy_irq
mess could be made private to itanic right away if there
wouldn't be the iommu/dmar driver being shared with x86. So to
do that I'm going to add a separate ia64 specific implementation
later in order not to deep-six itanic right away.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20140507154334.208629358@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those
interrupts are hardwired and we don't have the irq domain translation
like PPC. So one of these interrupts can be hooked up later to one of
the devices which are hard wired to it and the io_apic init code for
that particular interrupt line happily reuses that descriptor with a
completely different configuration so hell breaks lose.
Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
except for a few usage sites which have not yet blown up in our face
for whatever reason. But for drivers which need an irq range, like the
GPIO drivers, we have no limit in place and we don't want to expose
such a detail to a driver.
To cure this introduce a function which an architecture can implement
to impose a lower bound on the dynamic interrupt allocations.
Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
the end of the hardwired interrupt space, so all dynamic allocations
happen above.
That not only allows the GPIO driver to work sanely, it also protects
the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
htirq code. They need to be cleaned up as well, but that's a separate
issue.
Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Krogerus Heikki <heikki.krogerus@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There is a common pattern all over the place:
kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq));
This results in a call to core code anyway. So provide a function
which does the same thing in core.
While at it, replace the butt ugly macro with an inline.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140223212737.422068876@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In allmodconfig builds for sparc and any other arch which does
not set CONFIG_SPARSE_IRQ, the following will be seen at modpost:
CC [M] lib/cpu-notifier-error-inject.o
CC [M] lib/pm-notifier-error-inject.o
ERROR: "irq_to_desc" [drivers/gpio/gpio-mcp23s08.ko] undefined!
make[2]: *** [__modpost] Error 1
This happens because commit 3911ff30f5 ("genirq: export
handle_edge_irq() and irq_to_desc()") added one export for it, but
there were actually two instances of it, in an if/else clause for
CONFIG_SPARSE_IRQ. Add the second one.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: stable@vger.kernel.org # 3.4+
Link: http://lkml.kernel.org/r/1392057610-11514-1-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Export handle_edge_irq() and irq_to_desc() to modules to allow them to
do things such as
__irq_set_handler_locked(...., handle_edge_irq);
This fixes
ERROR: "handle_edge_irq" [drivers/gpio/gpio-pch.ko] undefined!
ERROR: "irq_to_desc" [drivers/gpio/gpio-pch.ko] undefined!
when gpio-pch is being built as a module.
This was introduced by commit df9541a60a ("gpio: pch9: Use proper flow
type handlers") that added
__irq_set_handler_locked(d->irq, handle_edge_irq);
but handle_edge_irq() was not exported for modules (and inlined
__irq_set_handler_locked() requires irq_to_desc() exported as well)
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Fix kernel-doc warning in irqdesc.c:
Warning(kernel/irq/irqdesc.c:353): No description found for parameter 'owner'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
When irq_alloc_descs() is called with no base IRQ specified then it will
search for a range of IRQs starting from a specified base address. In the
case where an IRQ is specified it still does this search in order to ensure
that none of the requested range is already allocated and it still uses the
from parameter to specify the base for the search. This means that in the
case where a base is specified but from is zero (which is reasonable as
any IRQ number is in the range specified by a zero from) the function will
get confused and try to allocate the first suitably sized block of free IRQs
it finds.
Instead use a specified IRQ as the base address for the search, and insist
that any from that is specified can support that IRQ.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Link: http://lkml.kernel.org/r/1307037313-15733-1-git-send-email-broonie@opensource.wolfsonmicro.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The genirq changes are initializing descriptors for sparse IRQs quite
differently from how non-sparse (stacked?) IRQs are initialized, with
the effect that on my platform all IRQs are default-disabled on sparse
IRQs and default-enabled if non-sparse IRQs are used, crashing some
GPIO driver.
Fix this by refactoring the non-sparse IRQs to use the same descriptor
init function as the sparse IRQs.
Signed-off: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/1306858479-16622-1-git-send-email-linus.walleij@stericsson.com
Cc: stable@kernel.org # 2.6.39
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Export handle_simple_irq, irq_modify_status, irq_alloc_descs,
irq_free_descs and generic_handle_irq to allow their usage in
modules. First user is IIO, which wants to be built modular, but needs
to be able to create irq chips, allocate and configure interrupt
descriptors and handle demultiplexing interrupts.
[ tglx: Moved the uninlinig of generic_handle_irq to a separate patch ]
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Link: http://lkml.kernel.org/r/%3C1305711544-505-1-git-send-email-jic23%40cam.ac.uk%3E
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>
kernel/irq/ is only built when CONFIG_GENERIC_HARDIRQS=y. So making
code inside of kernel/irq/ conditional on CONFIG_GENERIC_HARDIRQS is
pointless.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Thomas Gleixner