Pull irqchip updates for 4.15, take #4 from Marc Zyngier

 - A core irq fix for legacy cases where the irq trigger is not reported
   by firmware

 - A couple of GICv3/4 fixes (Kconfig, of-node refcount, error handling)

 - Trivial pr_err fixes

Pull irq core updates from Thomas Gleixner:
 "A rather large update for the interrupt core code and the irq chip drivers:

   - Add a new bitmap matrix allocator and supporting changes, which is
     used to replace the x86 vector allocator which comes with separate
     pull request. This allows to replace the convoluted nested loop
     allocation function in x86 with a facility which supports the
     recently added property of managed interrupts proper and allows to
     switch to a best effort vector reservation scheme, which addresses
     problems with vector exhaustion.

   - A large update to the ARM GIC-V3-ITS driver adding support for
     range selectors.

   - New interrupt controllers:
       - Meson and Meson8 GPIO
       - BCM7271 L2
       - Socionext EXIU

     If you expected that this will stop at some point, I have to
     disappoint you. There are new ones posted already. Sigh!

   - STM32 interrupt controller support for new platforms.

   - A pile of fixes, cleanups and updates to the MIPS GIC driver

   - The usual small fixes, cleanups and updates all over the place.
     Most visible one is to move the irq chip drivers Kconfig switches
     into a separate Kconfig menu"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  genirq: Fix type of shifting literal 1 in __setup_irq()
  irqdomain: Drop pointless NULL check in virq_debug_show_one
  genirq/proc: Return proper error code when irq_set_affinity() fails
  irq/work: Use llist_for_each_entry_safe
  irqchip: mips-gic: Print warning if inherited GIC base is used
  irqchip/mips-gic: Add pr_fmt and reword pr_* messages
  irqchip/stm32: Move the wakeup on interrupt mask
  irqchip/stm32: Fix initial values
  irqchip/stm32: Add stm32h7 support
  dt-bindings/interrupt-controllers: Add compatible string for stm32h7
  irqchip/stm32: Add multi-bank management
  irqchip/stm32: Select GENERIC_IRQ_CHIP
  irqchip/exiu: Add support for Socionext Synquacer EXIU controller
  dt-bindings: Add description of Socionext EXIU interrupt controller
  irqchip/gic-v3-its: Fix VPE activate callback return value
  irqchip: mips-gic: Make IPI bitmaps static
  irqchip: mips-gic: Share register writes in gic_set_type()
  irqchip: mips-gic: Remove gic_vpes variable
  irqchip: mips-gic: Use num_possible_cpus() to reserve IPIs
  irqchip: mips-gic: Configure EIC when CPUs come online
  ...

If ffz() ever returns a value >= 31 then the following shift is undefined
behaviour because the literal 1 which gets shifted is treated as signed
integer.

In practice, the bug is probably harmless, since the first undefined shift
count is 31 which results - ignoring UB - in (int)(0x80000000). This gets
sign extended so bit 32-63 will be set as well and all subsequent
__setup_irq() calls would just end up hitting the -EBUSY branch.

However, a sufficiently aggressive optimizer may use the UB of 1<<31
to decide that doesn't happen, and hence elide the sign-extension
code, so that subsequent calls can indeed get ffz > 31.

In any case, the right thing to do is to make the literal 1UL.

[ tglx: For this to happen a single interrupt would have to be shared by 32
  	devices. Hardware like that does not exist and would have way more
  	problems than that. ]

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171030213548.16831-1-linux@rasmusvillemoes.dk

When requesting a shared interrupt, we assume that the firmware
support code (DT or ACPI) has called irqd_set_trigger_type
already, so that we can retrieve it and check that the requester
is being reasonnable.

Unfortunately, we still have non-DT, non-ACPI systems around,
and these guys won't call irqd_set_trigger_type before requesting
the interrupt. The consequence is that we fail the request that
would have worked before.

We can either chase all these use cases (boring), or address it
in core code (easier). Let's have a per-irq_desc flag that
indicates whether irqd_set_trigger_type has been called, and
let's just check it when checking for a shared interrupt.
If it hasn't been set, just take whatever the interrupt
requester asks.

Fixes: 382bd4de6182 ("genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Petr Cvek <petrcvekcz@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

It is currently unclear how to set the VCPU affinity for a percpu_devid
interrupt , since the Linux irq_data structure describes the state for
multiple interrupts, one for each physical CPU on the system.  Since
each such interrupt can be associated with different VCPUs or none at
all, associating a single VCPU state with such an interrupt does not
capture the necessary semantics.

The implementers of irq_set_affinity are the Intel and AMD IOMMUs, and
the ARM GIC irqchip.  The Intel and AMD callers do not appear to use
percpu_devid interrupts, and the ARM GIC implementation only checks the
pointer against NULL vs. non-NULL.

Therefore, simply update the function documentation to explain the
expected use in the context of percpu_devid interrupts, allowing future
changes or additions to irqchip implementers to do the right thing.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvm@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/1509093281-15225-13-git-send-email-cdall@linaro.org

Managed interrupts can end up in a stale state on CPU hotplug. If the
interrupt is not targeting a single CPU, i.e. the affinity mask spawns
multiple CPUs then the following can happen:

After boot:

dstate:   0x01601200
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 24
pending:  0

After offlining CPU 31 - 24

dstate:   0x01a31000
            IRQD_IRQ_DISABLED
            IRQD_IRQ_MASKED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_AFFINITY_MANAGED
            IRQD_MANAGED_SHUTDOWN
node:     0
affinity: 24-31
effectiv: 24
pending:  0

Now CPU 25 gets onlined again, so it should get the effective interrupt
affinity for this interruopt, but due to the x86 interrupt affinity setter
restrictions this ends up after restarting the interrupt with:

dstate:   0x01601300
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_SETAFFINITY_PENDING
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 24
pending:  24-31

So the interrupt is still affine to CPU 24, which was the last CPU to go
offline of that affinity set and the move to an online CPU within 24-31,
in this case 25, is pending. This mechanism is x86/ia64 specific as those
architectures cannot move interrupts from thread context and do this when
an interrupt is actually handled. So the move is set to pending.

Whats worse is that offlining CPU 25 again results in:

dstate:   0x01601300
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_SET
            IRQD_SETAFFINITY_PENDING
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 24
pending:  24-31

This means the interrupt has not been shut down, because the outgoing CPU
is not in the effective affinity mask, but of course nothing notices that
the effective affinity mask is pointing at an offline CPU.

In the case of restarting a managed interrupt the move restriction does not
apply, so the affinity setting can be made unconditional. This needs to be
done _before_ the interrupt is started up as otherwise the condition for
moving it from thread context would not longer be fulfilled.

With that change applied onlining CPU 25 after offlining 31-24 results in:

dstate:   0x01600200
            IRQD_ACTIVATED
            IRQD_IRQ_STARTED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_MANAGED
node:     0
affinity: 24-31
effectiv: 25
pending:  

And after offlining CPU 25:

dstate:   0x01a30000
            IRQD_IRQ_DISABLED
            IRQD_IRQ_MASKED
            IRQD_SINGLE_TARGET
            IRQD_AFFINITY_MANAGED
            IRQD_MANAGED_SHUTDOWN
node:     0
affinity: 24-31
effectiv: 25
pending:  

which is the correct and expected result.

Fixes: 761ea388e8c4 ("genirq: Handle managed irqs gracefully in irq_startup()")
Reported-by: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: axboe@kernel.dk
Cc: linux-scsi@vger.kernel.org
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: mpe@ellerman.id.au
Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: keith.busch@intel.com
Cc: peterz@infradead.org
Cc: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1710042208400.2406@nanos

Emit a one time warning when the effective affinity mask is enabled in
Kconfig, but the interrupt chip does not update the mask in its
irq_set_affinity() callback,

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1710042208400.2406@nanos                                                                                                                                                                                                        

Activation of an interrupt and startup are currently a combo
functionlity. That works so far, but upcoming changes require a strict
separation because the activation can fail in future.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.754334077@linutronix.de

Currently the debugfs shows only information about actively used interrupts
like /proc/irq/ does. That's fine for most cases, but not helpful when
internals of allocated, but unused interrupt descriptors have to
debugged. It's also useful to provide information about all descriptors so
leaks can be debugged in a simpler way.

Move the debugfs registration to the descriptor allocation code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.355525908@linutronix.de

__free_irq() can return a NULL irqaction for example when trying to free
already-free IRQ, but the callsite unconditionally dereferences the
returned pointer.

Fix this by adding a check and return NULL.

Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20170919200412.GA29985@gmail.com