Commit Graph

13 Commits

Author SHA1 Message Date
Linus Torvalds 91552ab8ff The usual updates from the irq departement:
Core changes:
 
  - Provide IRQF_NO_AUTOEN as a flag for request*_irq() so drivers can be
    cleaned up which either use a seperate mechanism to prevent auto-enable
    at request time or have a racy mechanism which disables the interrupt
    right after request.
 
  - Get rid of the last usage of irq_create_identity_mapping() and remove
    the interface.
 
  - An overhaul of tasklet_disable(). Most usage sites of tasklet_disable()
    are in task context and usually in cleanup, teardown code pathes.
    tasklet_disable() spinwaits for a tasklet which is currently executed.
    That's not only a problem for PREEMPT_RT where this can lead to a live
    lock when the disabling task preempts the softirq thread. It's also
    problematic in context of virtualization when the vCPU which runs the
    tasklet is scheduled out and the disabling code has to spin wait until
    it's scheduled back in. Though there are a few code pathes which invoke
    tasklet_disable() from non-sleepable context. For these a new disable
    variant which still spinwaits is provided which allows to switch
    tasklet_disable() to a sleep wait mechanism. For the atomic use cases
    this does not solve the live lock issue on PREEMPT_RT. That is mitigated
    by blocking on the RT specific softirq lock.
 
  - The PREEMPT_RT specific implementation of softirq processing and
    local_bh_disable/enable().
 
    On RT enabled kernels soft interrupt processing happens always in task
    context and all interrupt handlers, which are not explicitly marked to
    be invoked in hard interrupt context are forced into task context as
    well. This allows to protect against softirq processing with a per
    CPU lock, which in turn allows to make BH disabled regions preemptible.
 
    Most of the softirq handling code is still shared. The RT/non-RT
    specific differences are addressed with a set of inline functions which
    provide the context specific functionality. The local_bh_disable() /
    local_bh_enable() mechanism are obviously seperate.
 
  - The usual set of small improvements and cleanups
 
 Driver changes:
 
  - New drivers for Nuvoton WPCM450 and DT 79rc3243x interrupt controllers
 
  - Extended functionality for MStar, STM32 and SC7280 irq chips
 
  - Enhanced robustness for ARM GICv3/4.1 drivers
 
  - The usual set of cleanups and improvements all over the place
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Merge tag 'irq-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "The usual updates from the irq departement:

  Core changes:

   - Provide IRQF_NO_AUTOEN as a flag for request*_irq() so drivers can
     be cleaned up which either use a seperate mechanism to prevent
     auto-enable at request time or have a racy mechanism which disables
     the interrupt right after request.

   - Get rid of the last usage of irq_create_identity_mapping() and
     remove the interface.

   - An overhaul of tasklet_disable().

     Most usage sites of tasklet_disable() are in task context and
     usually in cleanup, teardown code pathes. tasklet_disable()
     spinwaits for a tasklet which is currently executed. That's not
     only a problem for PREEMPT_RT where this can lead to a live lock
     when the disabling task preempts the softirq thread. It's also
     problematic in context of virtualization when the vCPU which runs
     the tasklet is scheduled out and the disabling code has to spin
     wait until it's scheduled back in.

     There are a few code pathes which invoke tasklet_disable() from
     non-sleepable context. For these a new disable variant which still
     spinwaits is provided which allows to switch tasklet_disable() to a
     sleep wait mechanism. For the atomic use cases this does not solve
     the live lock issue on PREEMPT_RT. That is mitigated by blocking on
     the RT specific softirq lock.

   - The PREEMPT_RT specific implementation of softirq processing and
     local_bh_disable/enable().

     On RT enabled kernels soft interrupt processing happens always in
     task context and all interrupt handlers, which are not explicitly
     marked to be invoked in hard interrupt context are forced into task
     context as well. This allows to protect against softirq processing
     with a per CPU lock, which in turn allows to make BH disabled
     regions preemptible.

     Most of the softirq handling code is still shared. The RT/non-RT
     specific differences are addressed with a set of inline functions
     which provide the context specific functionality. The
     local_bh_disable() / local_bh_enable() mechanism are obviously
     seperate.

   - The usual set of small improvements and cleanups

  Driver changes:

   - New drivers for Nuvoton WPCM450 and DT 79rc3243x interrupt
     controllers

   - Extended functionality for MStar, STM32 and SC7280 irq chips

   - Enhanced robustness for ARM GICv3/4.1 drivers

   - The usual set of cleanups and improvements all over the place"

* tag 'irq-core-2021-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  irqchip/xilinx: Expose Kconfig option for Zynq/ZynqMP
  irqchip/gic-v3: Do not enable irqs when handling spurious interrups
  dt-bindings: interrupt-controller: Add IDT 79RC3243x Interrupt Controller
  irqchip: Add support for IDT 79rc3243x interrupt controller
  irqdomain: Drop references to recusive irqdomain setup
  irqdomain: Get rid of irq_create_strict_mappings()
  irqchip/jcore-aic: Kill use of irq_create_strict_mappings()
  ARM: PXA: Kill use of irq_create_strict_mappings()
  irqchip/gic-v4.1: Disable vSGI upon (GIC CPUIF < v4.1) detection
  irqchip/tb10x: Use 'fallthrough' to eliminate a warning
  genirq: Reduce irqdebug cacheline bouncing
  kernel: Initialize cpumask before parsing
  irqchip/wpcm450: Drop COMPILE_TEST
  irqchip/irq-mst: Support polarity configuration
  irqchip: Add driver for WPCM450 interrupt controller
  dt-bindings: interrupt-controller: Add nuvoton, wpcm450-aic
  dt-bindings: qcom,pdc: Add compatible for sc7280
  irqchip/stm32: Add usart instances exti direct event support
  irqchip/gic-v3: Fix OF_BAD_ADDR error handling
  irqchip/sifive-plic: Mark two global variables __ro_after_init
  ...
2021-04-26 09:43:16 -07:00
Bartosz Golaszewski 883ccef355 genirq/irq_sim: Shrink devm_irq_domain_create_sim()
The custom devres structure manages only a single pointer which can
can be achieved by using devm_add_action_or_reset() as well which
makes the code simpler.

[ tglx: Fixed return value handling - found by smatch ]

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210301142659.8971-1-brgl@bgdev.pl
2021-03-30 13:21:27 +02:00
Andy Shevchenko ef4cb70a4c genirq/irq_sim: Fix typos in kernel doc (fnode -> fwnode)
Fix typos in kernel doc, otherwise validation script complains:

.../irq_sim.c:170: warning: Function parameter or member 'fwnode' not described in 'irq_domain_create_sim'
.../irq_sim.c:170: warning: Excess function parameter 'fnode' description in 'irq_domain_create_sim'
.../irq_sim.c:240: warning: Function parameter or member 'fwnode' not described in 'devm_irq_domain_create_sim'
.../irq_sim.c:240: warning: Excess function parameter 'fnode' description in 'devm_irq_domain_create_sim'

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210302161453.28540-1-andriy.shevchenko@linux.intel.com
2021-03-16 16:20:58 +01:00
Bartosz Golaszewski 337cbeb2c1 genirq/irq_sim: Simplify the API
The interrupt simulator API exposes a lot of custom data structures and
functions and doesn't reuse the interfaces already exposed by the irq
subsystem. This patch tries to address it.

We hide all the simulator-related data structures from users and instead
rely on the well-known irq domain. When creating the interrupt simulator
the user receives a pointer to a newly created irq_domain and can use it
to create mappings for simulated interrupts.

It is also possible to pass a handle to fwnode when creating the simulator
domain and retrieve it using irq_find_matching_fwnode().

The irq_sim_fire() function is dropped as well. Instead we implement the
irq_get/set_irqchip_state interface.

We modify the two modules that use the simulator at the same time as
adding these changes in order to reduce the intermediate bloat that would
result when trying to migrate the drivers in separate patches.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO
Link: https://lore.kernel.org/r/20200514083901.23445-3-brgl@bgdev.pl
2020-05-18 10:30:21 +01:00
Bartosz Golaszewski 8d91ecc84d irq/irq_sim: add irq_set_type() callback
Implement the irq_set_type() callback and call irqd_set_trigger_type()
internally so that users interested in the configured trigger type can
later retrieve it using irqd_get_trigger_type(). We only support edge
trigger types.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-19 17:42:28 +01:00
Bartosz Golaszewski 06459901d5 irq/irq_sim: Store multiple interrupt offsets in a bitmap
Two threads can try to fire the irq_sim with different offsets and will
end up fighting for the irq_work asignment. Thomas Gleixner suggested a
solution based on a bitfield where we set a bit for every offset
associated with an interrupt that should be fired and then iterate over
all set bits in the interrupt handler.

This is a slightly modified solution using a bitmap so that we don't
impose a limit on the number of interrupts one can allocate with
irq_sim.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-13 09:35:31 +00:00
Bartosz Golaszewski 275220ca6e genirq/irq_sim: Remove the license boilerplate
There is the SPDX license identifier now in the irq simulator. Remove the
license boilerplate.

While at it: update the copyright notice, since I did some changes in 2018.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20180426200747.8344-1-brgl@bgdev.pl
2018-04-26 22:26:39 +02:00
Thomas Gleixner 52a65ff560 genirq: Add missing SPDX identifiers
Add SPDX identifiers to files

 - which contain an explicit license boiler plate or reference

 - which do not contain a license reference and were not updated in the
   initial SPDX conversion because the license was deduced by the scanners
   via EXPORT_SYMBOL_GPL as GPL2.0 only.

[ tglx: Moved adding identifiers from the patch which removes the
  	references/boilerplate ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Link: https://lkml.kernel.org/r/20180314212030.668321222@linutronix.de
2018-03-20 14:23:28 +01:00
Bartosz Golaszewski f09777fa89 genirq/irq_sim: Return the base of the irq range from irq_sim_init()
Returning the base of the allocated interrupt range from irq_sim_init() and
devm_irq_sim_init() allows users to handle the logic of associating irq
numbers with any other driver-specific resources without having to use
irq_sim_irqnum().

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-4-brgl@bgdev.pl
2018-03-09 11:44:03 +01:00
Bartosz Golaszewski 28b6afa7d4 genirq/irq_sim: Check the return value of irq_sim_init() for error codes
As discussed with Marc Zyngier: irq_sim_init() and its devres variant
should return the base of the allocated interrupt range on success rather
than 0.

Make devm_irq_sim_init() check for an error code. This is a preparatory
change for modifying irq_sim_init() itself.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-3-brgl@bgdev.pl
2018-03-09 11:44:03 +01:00
Bartosz Golaszewski 34a866bd45 genirq/irq_sim: Explicitly include slab.h
kfree() is used in the irq_sim code but slab.h is pulled in indirectly via
irq.h. Include it explicitly.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-2-brgl@bgdev.pl
2018-03-09 11:44:03 +01:00
Bartosz Golaszewski 44e72c7ebf genirq/irq_sim: Add a devres variant of irq_sim_init()
Add a resource managed version of irq_sim_init(). This can be
conveniently used in device drivers.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Link: http://lkml.kernel.org/r/20170814145318.6495-3-brgl@bgdev.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-08-16 16:40:02 +02:00
Bartosz Golaszewski b19af510e6 genirq/irq_sim: Add a simple interrupt simulator framework
Implement a simple, irq_work-based framework for simulating
interrupts. Currently the API exposes routines for initializing and
deinitializing the simulator object, enqueueing the interrupts and
retrieving the allocated interrupt numbers based on the offset of the
dummy interrupt in the simulator struct.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Link: http://lkml.kernel.org/r/20170814145318.6495-2-brgl@bgdev.pl
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-08-16 16:40:02 +02:00