The entry rework moved interrupt entry code from the irqentry to the
noinstr section which made the irqentry section empty.

This breaks boundary checks which rely on the __irqentry_text_start/end
markers to find out whether a function in a stack trace is
interrupt/exception entry code. This affects the function graph tracer and
filter_irq_stacks().

As the IDT entry points are all sequentialy emitted this is rather simple
to unbreak by injecting __irqentry_text_start/end as global labels.

To make this work correctly:

  - Remove the IRQENTRY_TEXT section from the x86 linker script
  - Define __irqentry so it breaks the build if it's used
  - Adjust the entry mirroring in PTI
  - Remove the redundant kprobes and unwinder bound checks
Reported-by: NQian Cai <cai@lca.pw>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Error injection mechanisms need a half ways safe way to inject interrupts as
invoking generic_handle_irq() or the actual device interrupt handler
directly from e.g. a debugfs write is not guaranteed to be safe.

On x86 generic_handle_irq() is unsafe due to the hardware trainwreck which
is the base of x86 interrupt delivery and affinity management.

Move the irq debugfs injection code into a separate function which can be
used by error injection code as well.

The implementation prevents at least that state is corrupted, but it cannot
close a very tiny race window on x86 which might result in a stale and not
serviced device interrupt under very unlikely circumstances.

This is explicitly for debugging and testing and not for production use or
abuse in random driver code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: NKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: NMarc Zyngier <maz@kernel.org>
Link: https://lkml.kernel.org/r/20200306130623.990928309@linutronix.de

While checking the results of the :c:func: removal, I noticed that there
was no documentation for request_irq(), and request_threaded_irq() was not
mentioned at all.  Add a kerneldoc comment for request_irq() and add
request_threaded_irq() to the list of functions.
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The softirq `HRTIMER_SOFTIRQ' was not used since commit c6eb3f70
("hrtimer: Get rid of hrtimer softirq").

But it got used again, beginning with commit 5da70160 ("hrtimer:
Implement support for softirq based hrtimers"), which did not remove the
comment. Remove it now.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191107091924.13410-1-bigeasy@linutronix.de

Switch force_irqthreads from a boot time modifiable variable to a compile
time constant when CONFIG_PREEMPT_RT is enabled.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190816160923.12855-1-bigeasy@linutronix.de

Introduce a new function, rearm_wake_irq(), allowing a wakeup IRQ
to be armed for systen wakeup detection again without running any
action handlers associated with it after it has been armed for
wakeup detection and triggered.

That is useful for IRQs, like ACPI SCI, that may deliver wakeup
as well as non-wakeup interrupts when armed for systen wakeup
detection.  In those cases, it may be possible to determine whether
or not the delivered interrupt is a systen wakeup one without
running the entire action handler (or handlers, if the IRQ is
shared) for the IRQ, and if the interrupt turns out to be a
non-wakeup one, the IRQ can be rearmed with the help of the
new function.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

Convert the PM documents to ReST, in order to allow them to
build with Sphinx.

The conversion is actually:
  - add blank lines and indentation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NMark Brown <broonie@kernel.org>
Acked-by: NSrivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>

There are no more users of this interface.
Remove it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: https://lkml.kernel.org/r/20190301224821.29843-4-bigeasy@linutronix.de

The interrupt affinity spreading mechanism supports to spread out
affinities for one or more interrupt sets. A interrupt set contains one or
more interrupts. Each set is mapped to a specific functionality of a
device, e.g. general I/O queues and read I/O queus of multiqueue block
devices.

The number of interrupts per set is defined by the driver. It depends on
the total number of available interrupts for the device, which is
determined by the PCI capabilites and the availability of underlying CPU
resources, and the number of queues which the device provides and the
driver wants to instantiate.

The driver passes initial configuration for the interrupt allocation via a
pointer to struct irq_affinity.

Right now the allocation mechanism is complex as it requires to have a loop
in the driver to determine the maximum number of interrupts which are
provided by the PCI capabilities and the underlying CPU resources.  This
loop would have to be replicated in every driver which wants to utilize
this mechanism. That's unwanted code duplication and error prone.

In order to move this into generic facilities it is required to have a
mechanism, which allows the recalculation of the interrupt sets and their
size, in the core code. As the core code does not have any knowledge about the
underlying device, a driver specific callback is required in struct
irq_affinity, which can be invoked by the core code. The callback gets the
number of available interupts as an argument, so the driver can calculate the
corresponding number and size of interrupt sets.

At the moment the struct irq_affinity pointer which is handed in from the
driver and passed through to several core functions is marked 'const', but for
the callback to be able to modify the data in the struct it's required to
remove the 'const' qualifier.

Add the optional callback to struct irq_affinity, which allows drivers to
recalculate the number and size of interrupt sets and remove the 'const'
qualifier.

For simple invocations, which do not supply a callback, a default callback
is installed, which just sets nr_sets to 1 and transfers the number of
spreadable vectors to the set_size array at index 0.

This is for now guarded by a check for nr_sets != 0 to keep the NVME driver
working until it is converted to the callback mechanism.

To make sure that the driver configuration is correct under all circumstances
the callback is invoked even when there are no interrupts for queues left,
i.e. the pre/post requirements already exhaust the numner of available
interrupts.

At the PCI layer irq_create_affinity_masks() has to be invoked even for the
case where the legacy interrupt is used. That ensures that the callback is
invoked and the device driver can adjust to that situation.

[ tglx: Fixed the simple case (no sets required). Moved the sanity check
  	for nr_sets after the invocation of the callback so it catches
  	broken drivers. Fixed the kernel doc comments for struct
  	irq_affinity and de-'This patch'-ed the changelog ]
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: linux-nvme@lists.infradead.org
Cc: linux-pci@vger.kernel.org
Cc: Keith Busch <keith.busch@intel.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com>
Link: https://lkml.kernel.org/r/20190216172228.512444498@linutronix.de

The interrupt affinity spreading mechanism supports to spread out
affinities for one or more interrupt sets. A interrupt set contains one
or more interrupts. Each set is mapped to a specific functionality of a
device, e.g. general I/O queues and read I/O queus of multiqueue block
devices.

The number of interrupts per set is defined by the driver. It depends on
the total number of available interrupts for the device, which is
determined by the PCI capabilites and the availability of underlying CPU
resources, and the number of queues which the device provides and the
driver wants to instantiate.

The driver passes initial configuration for the interrupt allocation via
a pointer to struct irq_affinity.

Right now the allocation mechanism is complex as it requires to have a
loop in the driver to determine the maximum number of interrupts which
are provided by the PCI capabilities and the underlying CPU resources.
This loop would have to be replicated in every driver which wants to
utilize this mechanism. That's unwanted code duplication and error
prone.

In order to move this into generic facilities it is required to have a
mechanism, which allows the recalculation of the interrupt sets and
their size, in the core code. As the core code does not have any
knowledge about the underlying device, a driver specific callback will
be added to struct affinity_desc, which will be invoked by the core
code. The callback will get the number of available interupts as an
argument, so the driver can calculate the corresponding number and size
of interrupt sets.

To support this, two modifications for the handling of struct irq_affinity
are required:

1) The (optional) interrupt sets size information is contained in a
   separate array of integers and struct irq_affinity contains a
   pointer to it.

   This is cumbersome and as the maximum number of interrupt sets is small,
   there is no reason to have separate storage. Moving the size array into
   struct affinity_desc avoids indirections and makes the code simpler.

2) At the moment the struct irq_affinity pointer which is handed in from
   the driver and passed through to several core functions is marked
   'const'.

   With the upcoming callback to recalculate the number and size of
   interrupt sets, it's necessary to remove the 'const'
   qualifier. Otherwise the callback would not be able to update the data.

Implement #1 and store the interrupt sets size in 'struct irq_affinity'.

No functional change.

[ tglx: Fixed the memcpy() size so it won't copy beyond the size of the
  	source. Fixed the kernel doc comments for struct irq_affinity and
  	de-'This patch'-ed the changelog ]
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: linux-nvme@lists.infradead.org
Cc: linux-pci@vger.kernel.org
Cc: Keith Busch <keith.busch@intel.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com>
Link: https://lkml.kernel.org/r/20190216172228.423723127@linutronix.de

All information and calculations in the interrupt affinity spreading code
is strictly unsigned int. Though the code uses int all over the place.

Convert it over to unsigned int.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: linux-nvme@lists.infradead.org
Cc: linux-pci@vger.kernel.org
Cc: Keith Busch <keith.busch@intel.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com>
Link: https://lkml.kernel.org/r/20190216172228.336424556@linutronix.de

Add support for percpu_devid interrupts treated as NMIs.

Percpu_devid NMIs need to be setup/torn down on each CPU they target.

The same restrictions as for global NMIs still apply for percpu_devid NMIs.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Add functionality to allocate interrupt lines that will deliver IRQs
as Non-Maskable Interrupts. These allocations are only successful if
the irqchip provides the necessary support and allows NMI delivery for the
interrupt line.

Interrupt lines allocated for NMI delivery must be enabled/disabled through
enable_nmi/disable_nmi_nosync to keep their state consistent.

To treat a PERCPU IRQ as NMI, the interrupt must not be shared nor threaded,
the irqchip directly managing the IRQ must be the root irqchip and the
irqchip cannot be behind a slow bus.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

A recent commit added a new field but did not update the kerneldoc comment,
leading to this build warning:

  ./include/linux/interrupt.h:268: warning: Function parameter or member 'is_managed' not described in 'irq_affinity_desc'

Add the missing information, making the docs build 0.001% quieter.

Fixes: c410abbb ("genirq/affinity: Add is_managed to struct irq_affinity_desc")
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Dou Liyang <douliyangs@gmail.com>
Link: https://lkml.kernel.org/r/20190108170432.59bae8a6@lwn.net

Devices which use managed interrupts usually have two classes of
interrupts:

  - Interrupts for multiple device queues
  - Interrupts for general device management

Currently both classes are treated the same way, i.e. as managed
interrupts. The general interrupts get the default affinity mask assigned
while the device queue interrupts are spread out over the possible CPUs.

Treating the general interrupts as managed is both a limitation and under
certain circumstances a bug. Assume the following situation:

 default_irq_affinity = 4..7

So if CPUs 4-7 are offlined, then the core code will shut down the device
management interrupts because the last CPU in their affinity mask went
offline.

It's also a limitation because it's desired to allow manual placement of
the general device interrupts for various reasons. If they are marked
managed then the interrupt affinity setting from both user and kernel space
is disabled. That limitation was reported by Kashyap and Sumit.

Expand struct irq_affinity_desc with a new bit 'is_managed' which is set
for truly managed interrupts (queue interrupts) and cleared for the general
device interrupts.

[ tglx: Simplify code and massage changelog ]
Reported-by: NKashyap Desai <kashyap.desai@broadcom.com>
Reported-by: NSumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: NDou Liyang <douliyangs@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: linux-pci@vger.kernel.org
Cc: shivasharan.srikanteshwara@broadcom.com
Cc: ming.lei@redhat.com
Cc: hch@lst.de
Cc: bhelgaas@google.com
Cc: douliyang1@huawei.com
Link: https://lkml.kernel.org/r/20181204155122.6327-3-douliyangs@gmail.com

The interrupt affinity management uses straight cpumask pointers to convey
the automatically assigned affinity masks for managed interrupts. The core
interrupt descriptor allocation also decides based on the pointer being non
NULL whether an interrupt is managed or not.

Devices which use managed interrupts usually have two classes of
interrupts:

  - Interrupts for multiple device queues
  - Interrupts for general device management

Currently both classes are treated the same way, i.e. as managed
interrupts. The general interrupts get the default affinity mask assigned
while the device queue interrupts are spread out over the possible CPUs.

Treating the general interrupts as managed is both a limitation and under
certain circumstances a bug. Assume the following situation:

 default_irq_affinity = 4..7

So if CPUs 4-7 are offlined, then the core code will shut down the device
management interrupts because the last CPU in their affinity mask went
offline.

It's also a limitation because it's desired to allow manual placement of
the general device interrupts for various reasons. If they are marked
managed then the interrupt affinity setting from both user and kernel space
is disabled.

To remedy that situation it's required to convey more information than the
cpumasks through various interfaces related to interrupt descriptor
allocation.

Instead of adding yet another argument, create a new data structure
'irq_affinity_desc' which for now just contains the cpumask. This struct
can be expanded to convey auxilliary information in the next step.

No functional change, just preparatory work.

[ tglx: Simplified logic and clarified changelog ]
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NDou Liyang <douliyangs@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: linux-pci@vger.kernel.org
Cc: kashyap.desai@broadcom.com
Cc: shivasharan.srikanteshwara@broadcom.com
Cc: sumit.saxena@broadcom.com
Cc: ming.lei@redhat.com
Cc: hch@lst.de
Cc: douliyang1@huawei.com
Link: https://lkml.kernel.org/r/20181204155122.6327-2-douliyangs@gmail.com

A driver may have a need to allocate multiple sets of MSI/MSI-X interrupts,
and have them appropriately affinitized.

Add support for defining a number of sets in the irq_affinity structure, of
varying sizes, and get each set affinitized correctly across the machine.

[ tglx: Minor changelog tweaks ]
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Cc: linux-block@vger.kernel.org
Link: https://lkml.kernel.org/r/20181102145951.31979-5-ming.lei@redhat.com

Fix a grammar mistake in <linux/interrupt.h>.

[ mingo: While at it also fix another similar error in another comment as well. ]
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181008111726.26286-1-geert%2Brenesas@glider.beSigned-off-by: NIngo Molnar <mingo@kernel.org>

s390 is now the last architecture that entirely overwrites
local_softirq_pending() and uses the according default definitions of
set_softirq_pending() and or_softirq_pending().

Just move these to s390 to debloat the generic code complexity.
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NFrederic Weisbecker <frederic@kernel.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/1525786706-22846-12-git-send-email-frederic@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Consolidate and optimize default softirq mask API implementations.
Per-CPU operations are expected to be faster and a few architectures
already rely on them to implement local_softirq_pending() and related
accessors/mutators. Those will be migrated to the new generic code.
Signed-off-by: NFrederic Weisbecker <frederic@kernel.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/1525786706-22846-6-git-send-email-frederic@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

It seems that <linux/interrupt.h> does not need <linux/linkage.h>
nor <linux/preempt.h>.  8 kernels builds are successful without
these 2 headers (allmodconfig, allyesconfig, allnoconfig, and
tinyconfig on both i386 and x86_64).

<linux/interrupt.h> is #included 3875 times in 4.16-rc1, so this
reduces #include processing of these 2 files by a total of 7750 times.

Since I only tested x86 builds, this needs to be tested on other
$ARCHes as well.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/b24b9ec8-4970-65f5-759a-911d4ba2fcf0@infradead.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Fix up makefiles, remove references, and git rm kmemcheck.

Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.comSigned-off-by: NSasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Generate irqentry and softirqentry text sections without
any Kconfig dependencies. This will add extra sections, but
there should be no performace impact.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S . Miller <davem@davemloft.net>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-cris-kernel@axis.com
Cc: mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/150172789110.27216.3955739126693102122.stgit@devboxSigned-off-by: NIngo Molnar <mingo@kernel.org>

The irq timings infrastructure tracks when interrupts occur in order to
statistically predict te next interrupt event.

There is no point to track timer interrupts and try to predict them because
the next expiration time is already known. This can be avoided via the
IRQF_TIMER flag which is passed by timer drivers in request_irq(). It marks
the interrupt as timer based which alloes to ignore these interrupts in the
timings code.

Per CPU interrupts which are requested via request_percpu_+irq() have no
flag argument, so marking per cpu timer interrupts is not possible and they
get tracked pointlessly.

Add __request_percpu_irq() as a variant of request_percpu_irq() with a
flags argument and make request_percpu_irq() an inline wrapper passing
flags = 0.

The flag parameter is restricted to IRQF_TIMER as all other IRQF_ flags
make no sense for per cpu interrupts.

The next step is to convert all existing users of request_percpu_irq() and
then remove the wrapper and the underscores.

[ tglx: Massaged changelog ]
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: nicolas.pitre@linaro.org
Cc: vincent.guittot@linaro.org
Cc: rafael@kernel.org
Link: http://lkml.kernel.org/r/1499344144-3964-1-git-send-email-daniel.lezcano@linaro.org

An interrupt behaves with a burst of activity with periodic interval of time
followed by one or two peaks of longer interval.

As the time intervals are periodic, statistically speaking they follow a normal
distribution and each interrupts can be tracked individually.

Add a mechanism to compute the statistics on all interrupts, except the
timers which are deterministic from a prediction point of view, as their
expiry time is known.

The goal is to extract the periodicity for each interrupt, with the last
timestamp and sum them, so the next event can be predicted to a certain
extent.

Taking the earliest prediction gives the expected wakeup on the system
(assuming a timer won't expire before).
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-2-git-send-email-daniel.lezcano@linaro.org

The interrupt framework gives a lot of information about each interrupt. It
does not keep track of when those interrupts occur though, which is a
prerequisite for estimating the next interrupt arrival for power management
purposes.

Add a mechanism to record the timestamp for each interrupt occurrences in a
per-CPU circular buffer to help with the prediction of the next occurrence
using a statistical model.

Each CPU can store up to IRQ_TIMINGS_SIZE events <irq, timestamp>, the
current value of IRQ_TIMINGS_SIZE is 32.

Each event is encoded into a single u64, where the high 48 bits are used
for the timestamp and the low 16 bits are for the irq number.

A static key is introduced so when the irq prediction is switched off at
runtime, the overhead is near to zero.

It results in most of the code in internals.h for inline reasons and a very
few in the new file timings.c. The latter will contain more in the next patch
which will provide the statistical model for the next event prediction.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org

min_vecs is the minimum amount of vectors needed to operate in MSI-X mode
which may just include the vectors that don't need affinity.

Disabling affinity settings causes the qla2xxx driver scsi_add_host() to fail
when blk_mq is enabled as the blk_mq_pci_map_queues() expects affinity masks
on each vector.

Fixes: dfef358b ("PCI/MSI: Don't apply affinity if there aren't enough vectors left")
Signed-off-by: NMichael Hernandez <michael.hernandez@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org	# v4.10+

This allows callers to get back at them instead of having to store it in
another variable.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>

Only calculate the affinity for the main I/O vectors, and skip the
pre or post vectors specified by struct irq_affinity.

Also remove the irq_affinity cpumask argument that has never been used.
If we ever need it in the future we can pass it through struct
irq_affinity.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NJens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/1478654107-7384-4-git-send-email-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Only calculate the affinity for the main I/O vectors, and skip the pre or
post vectors specified by struct irq_affinity.

Also remove the irq_affinity cpumask argument that has never been used.  If
we ever need it in the future we can pass it through struct irq_affinity.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NJens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/1478654107-7384-3-git-send-email-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Some drivers (various network and RDMA adapter for example) have a MSI-X
vector layout where most of the vectors are used for I/O queues and should
have CPU affinity assigned to them, but some (usually 1 but sometimes more)
at the beginning or end are used for low-performance admin or configuration
work and should not have any explicit affinity assigned to them.

Add a new irq_affinity structure, which will be passed through a variant of
pci_irq_alloc_vectors that allows to specify these requirements (and is
extensible to any future quirks in that area) so that the core IRQ affinity
algorithm can take this quirks into account.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NJens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/1478654107-7384-2-git-send-email-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

No more users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Link: http://lkml.kernel.org/r/1473862739-15032-5-git-send-email-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The current irq spreading infrastructure is just looking at a cpumask and
tries to spread the interrupts over the mask. Thats suboptimal as it does
not take numa nodes into account.

Change the logic so the interrupts are spread across numa nodes and inside
the nodes. If there are more cpus than vectors per node, then we set the
affinity to several cpus. If HT siblings are available we take that into
account and try to set all siblings to a single vector.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Link: http://lkml.kernel.org/r/1473862739-15032-3-git-send-email-hch@lst.de

This is lifted from the blk-mq code and adopted to use the affinity mask
concept just introduced in the irq handling code.  It tries to keep the
algorithm the same as the one current used by blk-mq, but improvements
like assining vectors on a per-node basis instead of just per sibling
are possible with this simple move and refactoring.
Signed-off-by: NChristoph 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/1467621574-8277-7-git-send-email-hch@lst.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>.  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.
Signed-off-by: NAlexander Potapenko <glider@google.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Per the x86-specific footnote to PCI spec r3.0, sec 6.2.4, the value 255 in
the Interrupt Line register means "unknown" or "no connection."
Previously, when we couldn't derive an IRQ from the _PRT, we fell back to
using the value from Interrupt Line as an IRQ.  It's questionable whether
we should do that at all, but the spec clearly suggests we shouldn't do it
for the value 255 on x86.

Calling request_irq() with IRQ 255 may succeed, but the driver won't
receive any interrupts.  Or, if IRQ 255 is shared with another device, it
may succeed, and the driver's ISR will be called at random times when the
*other* device interrupts.  Or it may fail if another device is using IRQ
255 with incompatible flags.  What we *want* is for request_irq() to fail
predictably so the driver can fall back to polling.

On x86, assume 255 in the Interrupt Line means the INTx line is not
connected.  In that case, set dev->irq to IRQ_NOTCONNECTED so request_irq()
will fail gracefully with -ENOTCONN.

We found this problem on a system where Secure Boot firmware assigned
Interrupt Line 255 to an i801_smbus device and another device was already
using MSI-X IRQ 255.  This was in v3.10, where i801_probe() fails if
request_irq() fails:

  i801_smbus 0000:00:1f.3: enabling device (0140 -> 0143)
  i801_smbus 0000:00:1f.3: can't derive routing for PCI INT C
  i801_smbus 0000:00:1f.3: PCI INT C: no GSI
  genirq: Flags mismatch irq 255. 00000080 (i801_smbus) vs. 00000000 (megasa)
  CPU: 0 PID: 2487 Comm: kworker/0:1 Not tainted 3.10.0-229.el7.x86_64 #1
  Hardware name: FUJITSU PRIMEQUEST 2800E2/D3736, BIOS PRIMEQUEST 2000 Serie5
  Call Trace:
    dump_stack+0x19/0x1b
    __setup_irq+0x54a/0x570
    request_threaded_irq+0xcc/0x170
    i801_probe+0x32f/0x508 [i2c_i801]
    local_pci_probe+0x45/0xa0
  i801_smbus 0000:00:1f.3: Failed to allocate irq 255: -16
  i801_smbus: probe of 0000:00:1f.3 failed with error -16

After aeb8a3d1 ("i2c: i801: Check if interrupts are disabled"),
i801_probe() will fall back to polling if request_irq() fails.  But we
still need this patch because request_irq() may succeed or fail depending
on other devices in the system.  If request_irq() fails, i801_smbus will
work by falling back to polling, but if it succeeds, i801_smbus won't work
because it expects interrupts that it may not receive.
Signed-off-by: NChen Fan <chen.fan.fnst@cn.fujitsu.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The new name is irq_poll as iopoll is already taken.  Better suggestions
welcome.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>

Certain interrupt controller drivers have a register set that does not
make it easy to save/restore the mask of enabled/disabled interrupts
at suspend/resume time. At resume time, such drivers rely on the core
kernel irq subsystem to tell whether such or such interrupt is enabled
or not, in order to restore the proper state in the interrupt
controller register.

While the irqd_irq_disabled() provides the relevant information for
global interrupts, there is no similar function to query the
enabled/disabled state of a per-CPU interrupt.

Therefore, this commit complements the percpu_irq API with an
irq_percpu_is_enabled() function.

[ tglx: Simplified the implementation and added kerneldoc ]
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Tawfik Bayouk <tawfik@marvell.com>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Lior Amsalem <alior@marvell.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1445347435-2333-2-git-send-email-thomas.petazzoni@free-electrons.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Force threading of interrupts does not really deal with interrupts
which are requested with a primary and a threaded handler. The current
policy is to leave them alone and let the primary handler run in
interrupt context, but we set the ONESHOT flag for those interrupts as
well.

Kohji Okuno debugged a problem with the SDHCI driver where the
interrupt thread waits for a hardware interrupt to trigger, which can't
work well because the hardware interrupt is masked due to the ONESHOT
flag being set. He proposed to set the ONESHOT flag only if the
interrupt does not provide a thread handler.

Though that does not work either because these interrupts can be
shared. So the other interrupt would rightfully get the ONESHOT flag
set and therefor the same situation would happen again.

To deal with this proper, we need to force thread the primary handler
of such interrupts as well. That means that the primary interrupt
handler is treated as any other primary interrupt handler which is not
marked IRQF_NO_THREAD. The threaded handler becomes a separate thread
so the SDHCI flow logic can be handled gracefully.

The same issue was reported against 4.1-rt.
Reported-and-tested-by: NKohji Okuno <okuno.kohji@jp.panasonic.com>
Reported-By: NMichal Smucr <msmucr@gmail.com>
Reported-and-tested-by: NNathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1509211058080.5606@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>