linux-toradex.git/kernel/irq, branch v4.13-rc4

genirq/cpuhotplug: Revert "Set force affinity flag on hotplug migration"

2017-07-27T13:40:02+00:00

That commit was part of the changes moving x86 to the generic CPU hotplug
interrupt migration code. The force flag was required on x86 before the
hierarchical irqdomain rework, but invoking set_affinity() with force=true
stayed and had no side effects.

At some point in the past, the force flag got repurposed to support the
exynos timer interrupt affinity setting to a not yet online CPU, so the
interrupt controller callback does not verify the supplied affinity mask
against cpu_online_mask.

Setting the flag in the CPU hotplug code causes the cpu online masking to
be blocked on these irq controllers and results in potentially affining an
interrupt to the CPU which is unplugged, i.e. instead of moving it away,
it's just reassigned to it.

As the force flags is not longer needed on x86, it's safe to revert that
patch so the ARM irqchips which use the force flag work again.

Add comments to that effect, so this won't happen again.

Note: The online mask handling should be done in the generic code and the
force flag and the masking in the irq chips removed all together, but
that's not a change possible for 4.13. 

Fixes: 77f85e66aa8b ("genirq/cpuhotplug: Set force affinity flag on hotplug migration")
Reported-by: Will Deacon 
Signed-off-by: Thomas Gleixner 
Acked-by: Will Deacon 
Cc: Marc Zyngier 
Cc: Russell King 
Cc: LAK 
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1707271217590.3109@nanos
Signed-off-by: Thomas Gleixner

genirq/PM: Properly pretend disabled state when force resuming interrupts

2017-07-17T20:32:20+00:00

Interrupts with the IRQF_FORCE_RESUME flag set have also the
IRQF_NO_SUSPEND flag set. They are not disabled in the suspend path, but
must be forcefully resumed. That's used by XEN to keep IPIs enabled beyond
the suspension of device irqs. Force resume works by pretending that the
interrupt was disabled and then calling __irq_enable().

Incrementing the disabled depth counter was enough to do that, but with the
recent changes which use state flags to avoid unnecessary hardware access,
this is not longer sufficient. If the state flags are not set, then the
hardware callbacks are not invoked and the interrupt line stays disabled in
"hardware".

Set the disabled and masked state when pretending that an interrupt got
disabled by suspend.

Fixes: bf22ff45bed6 ("genirq: Avoid unnecessary low level irq function calls")
Suggested-by: Thomas Gleixner 
Signed-off-by: Juergen Gross 
Signed-off-by: Thomas Gleixner 
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: http://lkml.kernel.org/r/20170717174703.4603-2-jgross@suse.com

Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-07-17T20:00:36+00:00

Pull irq fix from Thomas Gleixner:
 "Fix the fallout from reworking the locking and resource management in
  request/free_irq()"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Keep chip buslock across irq_request/release_resources()

genirq: Keep chip buslock across irq_request/release_resources()

2017-07-12T08:14:42+00:00

Moving the irq_request/release_resources() callbacks out of the spinlocked,
irq disabled and bus locked region, unearthed an interesting abuse of the
irq_bus_lock/irq_bus_sync_unlock() callbacks.

The OMAP GPIO driver does merily power management inside of them. The
irq_request_resources() callback of this GPIO irqchip calls a function
which reads a GPIO register. That read aborts now because the clock of the
GPIO block is not magically enabled via the irq_bus_lock() callback.

Move the callbacks under the bus lock again to prevent this. In the
free_irq() path this requires to drop the bus_lock before calling
synchronize_irq() and reaquiring it before calling the
irq_release_resources() callback.

The bus lock can't be held because:

   1) The data which has been changed between bus_lock/un_lock is cached in
      the irq chip driver private data and needs to go out to the irq chip
      via the slow bus (usually SPI or I2C) before calling
      synchronize_irq().

      That's the reason why this bus_lock/unlock magic exists in the first
      place, as you cannot do SPI/I2C transactions while holding desc->lock
      with interrupts disabled.

   2) synchronize_irq() will actually deadlock, if there is a handler on
      flight. These chips use threaded handlers for obvious reasons, as
      they allow to do SPI/I2C communication. When the threaded handler
      returns then bus_lock needs to be taken in irq_finalize_oneshot() as
      we need to talk to the actual irq chip once more. After that the
      threaded handler is marked done, which makes synchronize_irq() return.

      So if we hold bus_lock accross the synchronize_irq() call, the
      handler cannot mark itself done because it blocks on the bus
      lock. That in turn makes synchronize_irq() wait forever on the
      threaded handler to complete....

Add the missing unlock of desc->request_mutex in the error path of
__free_irq() and add a bunch of comments to explain the locking and
protection rules.

Fixes: 46e48e257360 ("genirq: Move irq resource handling out of spinlocked region")
Reported-and-tested-by: Sebastian Reichel 
Reported-and-tested-by: Tony Lindgren 
Reported-by: Pavel Machek 
Signed-off-by: Thomas Gleixner 
Not-longer-ranted-at-by: Linus Torvalds 
Cc: Linus Walleij 
Cc: Grygorii Strashko 
Cc: Marc Zyngier

Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-07-09T17:24:46+00:00

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

Merge tag 'pci-v4.13-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2017-07-08T22:51:57+00:00

Pull PCI updates from Bjorn Helgaas:

  - add sysfs max_link_speed/width, current_link_speed/width (Wong Vee
    Khee)

  - make host bridge IRQ mapping much more generic (Matthew Minter,
    Lorenzo Pieralisi)

  - convert most drivers to pci_scan_root_bus_bridge() (Lorenzo
    Pieralisi)

  - mutex sriov_configure() (Jakub Kicinski)

  - mutex pci_error_handlers callbacks (Christoph Hellwig)

  - split ->reset_notify() into ->reset_prepare()/reset_done()
    (Christoph Hellwig)

  - support multiple PCIe portdrv interrupts for MSI as well as MSI-X
    (Gabriele Paoloni)

  - allocate MSI/MSI-X vector for Downstream Port Containment (Gabriele
    Paoloni)

  - fix MSI IRQ affinity pre/post/min_vecs issue (Michael Hernandez)

  - test INTx masking during enumeration, not at run-time (Piotr Gregor)

  - avoid using device_may_wakeup() for runtime PM (Rafael J. Wysocki)

  - restore the status of PCI devices across hibernation (Chen Yu)

  - keep parent resources that start at 0x0 (Ard Biesheuvel)

  - enable ECRC only if device supports it (Bjorn Helgaas)

  - restore PRI and PASID state after Function-Level Reset (CQ Tang)

  - skip DPC event if device is not present (Keith Busch)

  - check domain when matching SMBIOS info (Sujith Pandel)

  - mark Intel XXV710 NIC INTx masking as broken (Alex Williamson)

  - avoid AMD SB7xx EHCI USB wakeup defect (Kai-Heng Feng)

  - work around long-standing Macbook Pro poweroff issue (Bjorn Helgaas)

  - add Switchtec "running" status flag (Logan Gunthorpe)

  - fix dra7xx incorrect RW1C IRQ register usage (Arvind Yadav)

  - modify xilinx-nwl IRQ chip for legacy interrupts (Bharat Kumar
    Gogada)

  - move VMD SRCU cleanup after bus, child device removal (Jon Derrick)

  - add Faraday clock handling (Linus Walleij)

  - configure Rockchip MPS and reorganize (Shawn Lin)

  - limit Qualcomm TLP size to 2K (hardware issue) (Srinivas Kandagatla)

  - support Tegra MSI 64-bit addressing (Thierry Reding)

  - use Rockchip normal (not privileged) register bank (Shawn Lin)

  - add HiSilicon Kirin SoC PCIe controller driver (Xiaowei Song)

  - add Sigma Designs Tango SMP8759 PCIe controller driver (Marc
    Gonzalez)

  - add MediaTek PCIe host controller support (Ryder Lee)

  - add Qualcomm IPQ4019 support (John Crispin)

  - add HyperV vPCI protocol v1.2 support (Jork Loeser)

  - add i.MX6 regulator support (Quentin Schulz)

* tag 'pci-v4.13-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (113 commits)
  PCI: tango: Add Sigma Designs Tango SMP8759 PCIe host bridge support
  PCI: Add DT binding for Sigma Designs Tango PCIe controller
  PCI: rockchip: Use normal register bank for config accessors
  dt-bindings: PCI: Add documentation for MediaTek PCIe
  PCI: Remove __pci_dev_reset() and pci_dev_reset()
  PCI: Split ->reset_notify() method into ->reset_prepare() and ->reset_done()
  PCI: xilinx: Make of_device_ids const
  PCI: xilinx-nwl: Modify IRQ chip for legacy interrupts
  PCI: vmd: Move SRCU cleanup after bus, child device removal
  PCI: vmd: Correct comment: VMD domains start at 0x10000, not 0x1000
  PCI: versatile: Add local struct device pointers
  PCI: tegra: Do not allocate MSI target memory
  PCI: tegra: Support MSI 64-bit addressing
  PCI: rockchip: Use local struct device pointer consistently
  PCI: rockchip: Check for clk_prepare_enable() errors during resume
  MAINTAINERS: Remove Wenrui Li as Rockchip PCIe driver maintainer
  PCI: rockchip: Configure RC's MPS setting
  PCI: rockchip: Reconfigure configuration space header type
  PCI: rockchip: Split out rockchip_pcie_cfg_configuration_accesses()
  PCI: rockchip: Move configuration accesses into rockchip_pcie_cfg_atu()
  ...

irqdomain: Allow ACPI device nodes to be used as irqdomain identifiers

2017-07-07T10:13:29+00:00

A number of irqchip implementations are (ab)using the irqdomain allocator
by passing a fwnode that is neither a FWNODE_OF or a FWNODE_IRQCHIP.

This is pretty bad, but it also feels pretty crap to force these drivers to
allocate their own irqchip_fwid when they already have a proper fwnode.

Instead, let's teach the irqdomain allocator about ACPI device nodes, and
add some lovely name generation code... Tested on an arm64 D05 system.

Reported-and-tested-by: John Garry 
Signed-off-by: Marc Zyngier 
Signed-off-by: Thomas Gleixner 
Cc: Agustin Vega-Frias 
Cc: Ma Jun 
Cc: Hanjun Guo 
Link: http://lkml.kernel.org/r/20170707083959.10349-1-marc.zyngier@arm.com

genirq/debugfs: Remove redundant NULL pointer check

2017-07-07T06:57:57+00:00

debugfs_remove() can be called with a NULL pointer.

Fixes: 087cdfb662ae5 ("genirq/debugfs: Add proper debugfs interface")
Reported-by: Fengguang Wu 
Signed-off-by: Thomas Gleixner

genirq: Allow to pass the IRQF_TIMER flag with percpu irq request

2017-07-06T21:16:22+00:00

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: Daniel Lezcano 
Signed-off-by: Thomas Gleixner 
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

genirq/timings: Move free timings out of spinlocked region

2017-07-04T10:46:16+00:00

No point to do memory management from a interrupt disabled spin locked
region.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Marc Zyngier 
Cc: Daniel Lezcano 
Cc: Heiko Stuebner 
Cc: Julia Cartwright 
Cc: Linus Walleij 
Cc: Brian Norris 
Cc: Doug Anderson 
Cc: linux-rockchip@lists.infradead.org
Cc: John Keeping 
Cc: linux-gpio@vger.kernel.org
Link: http://lkml.kernel.org/r/20170629214344.196130646@linutronix.de