To support two stage irq vector spreading, it's required to add a starting
point to the spreading function. No functional change, just preparatory
work for the actual two stage change.

[ tglx: Renamed variables, tidied up the code and massaged changelog ]
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20180308105358.1506-4-ming.lei@redhat.com

No functional change, just prepare for converting to 2-stage irq vector
spreading.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20180308105358.1506-3-ming.lei@redhat.com

The following patches will introduce two stage irq spreading for improving
irq spread on all possible CPUs.

No functional change.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20180308105358.1506-2-ming.lei@redhat.com

When the allocation of node_to_possible_cpumask fails, then
irq_create_affinity_masks() returns with a pointer to the empty affinity
masks array, which will cause malfunction.

Reorder the allocations so the masks array allocation comes last and every
failure path returns NULL.

Fixes: 9a0ef98e ("genirq/affinity: Assign vectors to all present CPUs")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>

arm has an optional MULTI_IRQ_HANDLER, which openrisc copied but didn't
make optional.  The multi irq handler infrastructure has been copied to
generic code selectable with a new config symbol. That symbol can be
selected by randconfig builds and can cause build breakage.

Introduce CONFIG_MULTI_IRQ_HANDLER as an intermediate step which prevents
the core config symbol from being selected. The openrisc local config
symbol will be removed once openrisc gets converted to the generic code.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/20180404043130.31277-3-palmer@sifive.com

arm has an optional MULTI_IRQ_HANDLER, which arm64 copied but didn't make
optional.  The multi irq handler infrastructure has been copied to generic
code selectable with a new config symbol. That symbol can be selected by
randconfig builds and can cause build breakage.

Introduce CONFIG_MULTI_IRQ_HANDLER as an intermediate step which prevents
the core config symbol from being selected. The arm64 local config symbol
will be removed once arm64 gets converted to the generic code.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/20180404043130.31277-2-palmer@sifive.com

These config switches enable the same code in the core and the not yet
converted architecture code. They can be selected both by randconfig builds
and cause linker error because the same symbols are defined twice.

Make the new GENERIC_IRQ_MULTI_HANDLER depend on !MULTI_IRQ_HANDLER to
prevent that. The dependency will be removed once all architectures are
converted over.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/20180404043130.31277-4-palmer@sifive.com

Merge tag 'irqchip-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates for 4.17 from Marc Zyngier:

 - New Qualcomm PDC irqchip
 - New Microsemi Ocelot irqchip
 - Suspend/resume support for some oddball GICv3 irqchip
 - Better GIC/GICv3 support for kexec
 - Various cleanups and fixes

Most MMIO GIC register accesses use a 1-hot bit scheme that
avoids requiring any form of locking. This isn't true for the
GICD_ICFGRn registers, which require a RMW sequence.

Unfortunately, we seem to be missing a lock for these particular
accesses, which could result in a race condition if changing the
trigger type on any two interrupts within the same set of 16
interrupts (and thus controlled by the same CFGR register).

Introduce a private lock in the GIC common comde for this
particular case, making it cover both GIC implementations
in one go.

Cc: stable@vger.kernel.org
Signed-off-by: Aniruddha Banerjee <aniruddhab@nvidia.com>
[maz: updated changelog]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

No changes in semantics -- key init is true; replace

static_key_slow_dec       with   static_branch_disable
static_key_true           with   static_branch_likely

The first is because we never actually do any couterpart incs,
thus there is really no reference counting semantics going on.
Use the more proper static_branch_disable() construct.

Also added a '_key' suffix to supports_deactivate, for better
self documentation.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Booting with GICR_CTLR.EnableLPI=1 is usually a bad idea, and may
result in subtle memory corruption. Detecting this is thus pretty
important.

On detecting that LPIs are still enabled, we taint the kernel (because
we're not sure of anything anymore), and try to disable LPIs. This can
fail, as implementations are allowed to implement GICR_CTLR.EnableLPI
as a one-way enable, meaning the redistributors cannot be reprogrammed
with new tables.

Should this happen, we fail probing the redistributor and warn the user
that things are pretty dire.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
[maz: reworded changelog, minor comment and message changes]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

The Microsemi Ocelot SoC has a pretty simple IRQ controller in its ICPU
block. Add a driver for it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Add the Device Tree binding documentation for the Microsemi Ocelot
interrupt controller that is part of the ICPU. It is connected directly to
the MIPS core interrupt controller.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

We would like to reset the Group-0 Active Priority Registers
at boot time if they are available to us. They would be available
if SCR_EL3.FIQ was not set, but we cannot directly probe this bit,
and short of checking, we may end-up trapping to EL3, and the
firmware may not be please to get such an exception. Yes, this
is dumb.

Instead, let's use PMR to find out if its value gets affected by
SCR_EL3.FIQ being set. We use the fact that when SCR_EL3.FIQ is
set, the LSB of the priority is lost due to the shifting back and
forth of the actual priority. If we read back a 0, we know that
Group0 is unavailable. In case we read a non-zero value, we can
safely reset the AP0Rn register.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Clearing AP0Rn has created a number of regressions, due to systems
that have SCR_EL3.FIQ set. Even when addressing some obvious bugs,
GIC500 platforms seem to act bizarrely (we are supposed to have
5 bits of priority, but PMR seems to behave as if we had 6...).

Drop the AP0Rn reset for the time being, it is unlikely to have any
effect if kexec-ing.

Fixes: d6062a6d irqchip/gic-v3: Reset APgRn registers at boot time
Reported-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

We cannot know the trigger of partitionned PPIs ahead of time
(when we instanciate the partitions), so let's not check them
early.
Reported-by: JeffyChen <jeffy.chen@rock-chips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Now that SPDX identifiers are in place, remove the boilerplate or
references.

The change in timings.c has been acked by the author.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
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

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

Use the proper SPDX-Identifier format.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
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/20180314212030.492674761@linutronix.de

Remove pointless references to the file name itself and condense the
information so it wastes less space.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
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/20180314212030.412095827@linutronix.de

Given that irq_to_desc() is a radix_tree_lookup and the reverse
operation is only a pointer dereference and that all callers of
__free_irq already have the desc, pass the desc instead of the irq
number.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel@pengutronix.de
Link: https://lkml.kernel.org/r/20180319105202.9794-1-u.kleine-koenig@pengutronix.de

There is a huge number of broken device trees out there. Just
grepping through the tree for the use of IRQ_TYPE_NONE in conjunction
with the GIC is scary.

People just don't realise that IRQ_TYPE_NONE just doesn't exist, and
you just get whatever junk was there before. So let's make them aware
of the issue.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

There is a huge number of broken device trees out there. Just
grepping through the tree for the use of IRQ_TYPE_NONE in conjunction
with the GIC is scary.

People just don't realise that IRQ_TYPE_NONE just doesn't exist, and
you just get whatever junk was there before. So let's make them aware
of the issue.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

The existing mechanism for handling IRQs on RISC-V is pretty ugly: the irq
entry code selects the handler via Kconfig dependencies.

Use the new generic IRQ handling infastructure, which allows boot time
registration of the low level entry handler.

This does add an additional load to the interrupt latency, but there's a
lot of tuning left to be done there on RISC-V so it's OK for now.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: jonas@southpole.se
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux@armlinux.org.uk
Cc: stefan.kristiansson@saunalahti.fi
Cc: openrisc@lists.librecores.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180307235731.22627-3-palmer@sifive.com

The arm multi irq handler registration mechanism has been copied into a
handful of architectures, including arm64 and openrisc. RISC-V needs the
same mechanism.

Instead of adding yet another copy for RISC-V copy the arm implementation
into the core code depending on a new Kconfig symbol:
CONFIG_GENERIC_MULTI_IRQ_HANDLER.

Subsequent patches will convert the various architectures.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jonas@southpole.se
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux@armlinux.org.uk
Cc: stefan.kristiansson@saunalahti.fi
Cc: openrisc@lists.librecores.org
Cc: shorne@gmail.com
Cc: linux-riscv@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180307235731.22627-2-palmer@sifive.com

This adds functionality to resend the MAPC command to an ITS node on
resume. If the ITS is powered down during suspend and the collections
are not backed by memory, the ITS will lose that state. This just sets
up the known state for the collections after the ITS is restored.
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Some platforms power off GIC logic in suspend, so we need to
save/restore state. The distributor and redistributor registers need
to be handled in firmware code due to access permissions on those
registers, but the ITS registers can be restored in the kernel.

We limit this to systems where the ITS collections are implemented
in HW (as opposed to being backed by memory tables), as they are
the only ones that cannot be dealt with by the firmware.
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
[maz: fixed changelog, dropped DT property, limited to HCC being >0]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

For most GICv3 implementations, enabling LPIs is a one way switch.
Once they're on, there is no turning back, which completely kills
kexec (pending tables will always be live, and we can't tell the
secondary kernel where they are).

This is really annoying if you plan to use Linux as a bootloader,
as it pretty much guarantees that the secondary kernel won't be
able to use MSIs, and may even see some memory corruption. Bad.

A workaround for this unfortunate situation is to allow the kernel
not to enable LPIs, even if the feature is present in the HW. This
would allow Linux-as-a-bootloader to leave LPIs alone, and let the
secondary kernel to do whatever it wants with them.

Let's introduce a boolean "irqchip.gicv3_nolpi" command line option
that serves that purpose.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Booting a crash kernel while in an interrupt handler is likely
to leave the Active Priority Registers with some state that
is not relevant to the new kernel, and is likely to lead
to erratic behaviours such as interrupts not firing as their
priority is already active.

As a sanity measure, wipe the APRs clean on startup. We make
sure to wipe both group 0 and 1 registers in order to avoid
any surprise.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Booting a crash kernel while in an interrupt handler is likely
to leave the Active Priority Registers with some state that
is not relevant to the new kernel, and is likely to lead
to erratic behaviours such as interrupts not firing as their
priority is already active.

As a sanity measure, wipe the APRs clean on startup.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Add device binding documentation for the PDC Interrupt controller on
QCOM SoC's like the SDM845. The interrupt-controller can be used to
sense edge low interrupts and wakeup interrupts when the GIC is
non-operational.

Cc: devicetree@vger.kernel.org
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

The Power Domain Controller (PDC) on QTI SoCs like SDM845 houses an
interrupt controller along with other domain control functions to handle
interrupt related functions like handle falling edge or active low which
are not detected at the GIC and handle wakeup interrupts.

The interrupt controller is on an always-on domain for the purpose of
waking up the processor. Only a subset of the processor's interrupts are
routed through the PDC to the GIC. The PDC powers on the processors'
domain, when in low power mode and replays pending interrupts so the GIC
may wake up the processor.
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Since commit 6f46aedb ("irqchip: renesas-irqc: Add wake-up
support"), when an IRQ is used for wakeup, the INTC
block's module clock is manually kept running during system suspend, to
make sure the device stays active.

However, this explicit clock handling is merely a workaround for a
failure to properly communicate wakeup information to the device core.

Instead, set the device's power.wakeup_path field, to indicate this
device is part of the wakeup path.  Depending on the PM Domain's
active_wakeup configuration, the genpd core code will keep the device
enabled (and the clock running) during system suspend when needed.
This allows for the removal of all explicit clock handling code from the
driver.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Since commit 705bc96c ("irqchip: renesas-intc-irqpin: Add
minimal runtime PM support"), when an IRQ is used for wakeup, the INTC
block's module clock (if exists) is manually kept running during system
suspend, to make sure the device stays active.

However, this explicit clock handling is merely a workaround for a
failure to properly communicate wakeup information to the device core.

Instead, set the device's power.wakeup_path field, to indicate this
device is part of the wakeup path.  Depending on the PM Domain's
active_wakeup configuration, the genpd core code will keep the device
enabled (and the clock running) during system suspend when needed.
This allows for the removal of all explicit clock handling code from the
driver.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Pull NFS client bugfixes from Trond Myklebust:
 "Hightlights include the following stable fixes:

   - NFS: Fix an incorrect type in struct nfs_direct_req

   - pNFS: Prevent the layout header refcount going to zero in
     pnfs_roc()

   - NFS: Fix unstable write completion"

* tag 'nfs-for-4.16-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: Fix unstable write completion
  pNFS: Prevent the layout header refcount going to zero in pnfs_roc()
  NFS: Fix an incorrect type in struct nfs_direct_req

Pull x86/pti updates from Thomas Gleixner:
 "Yet another pile of melted spectrum related updates:

   - Drop native vsyscall support finally as it causes more trouble than
     benefit.

   - Make microcode loading more robust. There were a few issues
     especially related to late loading which are now surfacing because
     late loading of the IB* microcodes addressing spectre issues has
     become more widely used.

   - Simplify and robustify the syscall handling in the entry code

   - Prevent kprobes on the entry trampoline code which lead to kernel
     crashes when the probe hits before CR3 is updated

   - Don't check microcode versions when running on hypervisors as they
     are considered as lying anyway.

   - Fix the 32bit objtool build and a coment typo"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix kernel crash when probing .entry_trampoline code
  x86/pti: Fix a comment typo
  x86/microcode: Synchronize late microcode loading
  x86/microcode: Request microcode on the BSP
  x86/microcode/intel: Look into the patch cache first
  x86/microcode: Do not upload microcode if CPUs are offline
  x86/microcode/intel: Writeback and invalidate caches before updating microcode
  x86/microcode/intel: Check microcode revision before updating sibling threads
  x86/microcode: Get rid of struct apply_microcode_ctx
  x86/spectre_v2: Don't check microcode versions when running under hypervisors
  x86/vsyscall/64: Drop "native" vsyscalls
  x86/entry/64/compat: Save one instruction in entry_INT80_compat()
  x86/entry: Do not special-case clone(2) in compat entry
  x86/syscalls: Use COMPAT_SYSCALL_DEFINEx() macros for x86-only compat syscalls
  x86/syscalls: Use proper syscall definition for sys_ioperm()
  x86/entry: Remove stale syscall prototype
  x86/syscalls/32: Simplify $entry == $compat entries
  objtool: Fix 32-bit build

Pull timer fix from Thomas Gleixner:
 "Just a single fix which adds a missing Kconfig dependency to avoid
  unmet dependency warnings"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/atmel-st: Add 'depends on HAS_IOMEM' to fix unmet dependency

Pull RAS fixes from Thomas Gleixner:
 "Two small fixes for RAS/MCE:

   - Serialize sysfs changes to avoid concurrent modificaiton of
     underlying data

   - Add microcode revision to Machine Check records. This should have
     been there forever, but now with the broken microcode versions in
     the wild it has become important"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/MCE: Serialize sysfs changes
  x86/MCE: Save microcode revision in machine check records