irqchip/armada-370-xp: Suppress unused-function warning

armada_370_xp_msi_reenable_percpu() is only defined when CONFIG_PCI_MSI is
enabled, and only called when SMP is enabled.

Without CONFIG_SMP, there are no callers, which results in a build time
warning instead:

drivers/irqchip/irq-armada-370-xp.c:319:13: error: 'armada_370_xp_msi_reenable_percpu' defined but not used [-Werror=unused-function]
319 | static void armada_370_xp_msi_reenable_percpu(void) {}
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Mark the function as __maybe_unused to avoid adding more complexity
to the #ifdefs.

Fixes: 8ca61cde32c1 ("irqchip/armada-370-xp: Enable MSI affinity configuration")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240322125838.901649-1-arnd@kernel.org

irqchip: Use irq_domain_alloc_irqs()

Use the irq_domain_alloc_irqs() wrapper instead of the full
__irq_domain_alloc_irqs() interface, which was only intended for some
legacy (x86) use cases.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221213140844.15470-2-johan+linaro@kernel.org

irqchip/armada-370-xp: Do not touch Performance Counter Overflow on A375, A38x, A39x

Register ARMADA_370_XP_INT_FABRIC_MASK_OFFS is Armada 370 and XP specific
and on new Armada platforms it has different meaning. It does not configure
Performance Counter Overflow interrupt masking. So do not touch this
register on non-A370/XP platforms (A375, A38x and A39x).

Signed-off-by: Pali Rohár <pali@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 28da06dfd9e4 ("irqchip: armada-370-xp: Enable the PMU interrupts")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425113706.29310-1-pali@kernel.org

irqchip/armada-370-xp: Enable MSI affinity configuration

With multiple devices attached via PCIe to an Armada 385 it is possible
to overwhelm a single CPU with MSI interrupts. Under certain scenarios
configuring the interrupts to be handled by more than one CPU would
prevent the system from being overwhelmed. However the
irqchip-aramada-370-xp driver is configured to only handle MSIs on the
boot CPU, and provides no affinity configuration.

This change adds support to the armada-370-xp driver to allow for
configuring the affinity of specific MSI irqs and to generate the
interrupts on secondary CPUs. This is done by enabling the private
doorbell for all online CPUs and configures all CPUs to unmask MSI
specific private doorbell bits. The CPU affinity selection of the
interrupt is handled by the target list of the software triggered
interrupt value, which is provided as the MSI message. The message has
the associated CPU bit set for the target CPU. For private doorbell
interrupts only one bit can be set otherwise all CPUs will receive the
interrupt, so the lowest CPU in the affinity mask is used. This means
that by default the first CPU will handle all the interrupts as was the
case before.

Signed-off-by: Nathan Rossi <nathan.rossi@digi.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220422043532.146946-1-nathan@nathanrossi.com

irqchip/armada-370-xp: Fix support for Multi-MSI interrupts

irq-armada-370-xp driver already sets MSI_FLAG_MULTI_PCI_MSI flag into
msi_domain_info structure. But allocated interrupt numbers for Multi-MSI
needs to be properly aligned otherwise devices send MSI interrupt with
wrong number.

Fix this issue by using function bitmap_find_free_region() instead of
bitmap_find_next_zero_area() to allocate aligned interrupt numbers.

Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: a71b9412c90c ("irqchip/armada-370-xp: Allow allocation of multiple MSIs")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211125130057.26705-2-pali@kernel.org

irqchip/armada-370-xp: Fix return value of armada_370_xp_msi_alloc()

IRQ domain alloc function should return zero on success. Non-zero value
indicates failure.

Signed-off-by: Pali Rohár <pali@kernel.org>
Fixes: fcc392d501bd ("irqchip/armada-370-xp: Use the generic MSI infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211125130057.26705-1-pali@kernel.org

irq: remove handle_domain_{irq,nmi}()

Now that entry code handles IRQ entry (including setting the IRQ regs)
before calling irqchip code, irqchip code can safely call
generic_handle_domain_irq(), and there's no functional reason for it to
call handle_domain_irq().

Let's cement this split of responsibility and remove handle_domain_irq()
entirely, updating irqchip drivers to call generic_handle_domain_irq().

For consistency, handle_domain_nmi() is similarly removed and replaced
with a generic_handle_domain_nmi() function which also does not perform
any entry logic.

Previously handle_domain_{irq,nmi}() had a WARN_ON() which would fire
when they were called in an inappropriate context. So that we can
identify similar issues going forward, similar WARN_ON_ONCE() logic is
added to the generic_handle_*() functions, and comments are updated for
clarity and consistency.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>

irqchip/armada-370-xp: Fix ack/eoi breakage

When converting the driver to using handle_percpu_devid_irq,
we forgot to repaint the irq_eoi() callback into irq_ack(),
as handle_percpu_devid_fasteoi_ipi() was actually using EOI
really early in the handling. Yes this was a stupid idea.

Fix this by using the HW ack method as irq_ack().

Fixes: e52e73b7e9f7 ("irqchip/armada-370-xp: Make IPIs use handle_percpu_devid_irq()")
Reported-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Tested-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87tuiexq5f.fsf@pengutronix.de

irqchip: Bulk conversion to generic_handle_domain_irq()

Wherever possible, replace constructs that match either
generic_handle_irq(irq_find_mapping()) or
generic_handle_irq(irq_linear_revmap()) to a single call to
generic_handle_domain_irq().

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

irqchip/armada-370-xp: Make IPIs use handle_percpu_devid_irq()

As done for the Arm GIC irqchips, move IPIs to handle_percpu_devid_irq() as
handle_percpu_devid_fasteoi_ipi() isn't actually required.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201109094121.29975-3-valentin.schneider@arm.com

irqchip/armada-370-xp: Configure IPIs as standard interrupts

To introduce IPIs as standard interrupts to the Armada 370-XP
driver, let's allocate a completely separate irqdomain and
irqchip combo that lives parallel to the "standard" one.

This effectively should be modelled as a chained interrupt
controller, but the code is in such a state that it is
pretty hard to shoehorn, as it would require the rewrite
of the MSI layer as well.

Signed-off-by: Marc Zyngier <maz@kernel.org>

irqchip/armada-370-xp: Enable MSI-X support

Armada XP does not only support MSI, but also MSI-X. This patch sets
the MSI_FLAG_PCI_MSIX flag in the interrupt controller driver which
is the only change necessary to enable MSI-X support on this SoC. As
the Linux PCI MSI-X infrastructure takes care of writing the data and
address structures into the BAR specified by the MSI-X controller.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/armada-370-xp: Report that effective affinity is a single target

The Armada 370 XP driver only targets a single CPU at a time, even if
the notional affinity is wider. Let's inform the core code
about this.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Wei Xu <xuwei5@hisilicon.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20170818083925.10108-7-marc.zyngier@arm.com

irqchip/MSI: Use irq_domain_update_bus_token instead of an open coded access

Now that we have irq_domain_update_bus_token(), switch everyone over
to it. The debugfs code thanks you for your continued support.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Revert "irqchip/armada-370-xp: Fix regression by clearing IRQ_NOAUTOEN"

This reverts commit 353d6d6c82e5d2533ba22e7f9fb081582bf50dc2, which is
no longer needed, now that the irq-armada-370-xp driver properly
re-enables per-CPU interrupt on both the boot CPU and secondary CPUs
after resume.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/armada-370-xp: Re-enable per-CPU interrupts at resume time

Commit d17cab4451df1 ("irqchip: Kill off set_irq_flags usage") changed
the code of armada_370_xp_mpic_irq_map() from using set_irq_flags() to
irq_set_probe().

While the commit log seems to imply that there are no functional
changes, there are indeed functional changes introduced by this commit:
the IRQ_NOAUTOEN flag is no longer cleared. This functional change
caused a regression on Armada XP, which no longer works properly after
suspend/resume because per-CPU interrupts remain disabled. This
regression was temporarly worked around in commit
353d6d6c82e5d ("irqchip/armada-370-xp: Fix regression by clearing
IRQ_NOAUTOEN"), but it is not the most satisfying solution. This commit
implements the solution that was initially discussed with Thomas
Gleixner.

Due to how the hardware registers work, the irq-armada-370-xp cannot
simply save/restore a bunch of registers at suspend/resume to make sure
that the interrupts remain in the same state after resuming. Therefore,
it relies on the kernel to say whether the interrupt is disabled or not,
using the irqd_irq_disabled() function. This was all working fine while
the IRQ_NOAUTOEN flag was cleared.

With the change introduced by Rob Herring in d17cab4451df1, the
IRQ_NOAUTOEN flag is now set for all interrupts. irqd_irq_disabled()
returns false for per-CPU interrupts, and therefore our per-CPU
interrupts are no longer re-enabled after resume.

This commit fixes that by using irqd_irq_disabled() only for global
interrupts, and using the newly introduced irq_percpu_is_enabled() for
per-CPU interrupts.

Also, it fixes a related problems that per-CPU interrupts were only
re-enabled on the boot CPU and not other CPUs. Until now this wasn't a
problem since on this platform, only the local timers are using per-CPU
interrupts and the local timers of secondary CPUs are turned off/on
during CPU hotplug before suspend, after after resume. However, since
Linux 4.4, we are also be using per-CPU interrupts for the network
controller, so we need to properly restore the per-CPU interrupts on
secondary CPUs as well.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/armada-370-xp: Document the overall driver logic

Since the overall logic of the driver to handle the global and per-CPU
masking of the interrupts is far from trivial, this commit adds a long
comment detailing how the hardware operates and what strategy the
driver implements on top of that.

Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/armada-370-xp: Re-order register definitions

In order to clarify to which register base the various register
definitions apply, this commit re-orders them, and adds a comment that
clearly indicate which registers are relative to "main_int_base" and
which registers are relative to "per_cpu_int_base".

Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/armada-xp: Consolidate hotplug state space

The mpic is either the main interrupt controller or is cascaded behind a
GIC. The mpic is single instance and the modes are mutually exclusive, so
there is no reason to have seperate cpu hotplug states.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/20161221192112.333161745@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

cpu/hotplug: Cleanup state names

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip/armada: Avoid unused function warnings

When building with CONFIG_SMP disabled, we get some new harmless warnings:

drivers/irqchip/irq-armada-370-xp.c:356:12: error: 'mpic_cascaded_starting_cpu' defined but not used [-Werror=unused-function]
static int mpic_cascaded_starting_cpu(unsigned int cpu)
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/irqchip/irq-armada-370-xp.c:349:12: error: 'armada_xp_mpic_starting_cpu' defined but not used [-Werror=unused-function]
static int armada_xp_mpic_starting_cpu(unsigned int cpu)

This moves the unused functions into the #ifdef, as they previously were.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Cochran <rcochran@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Fixes: cb5ff2d245c1 ("irqchip/armada-370-xp: Convert to hotplug state machine")
Link: http://lkml.kernel.org/r/20160718160335.3134412-1-arnd@arndb.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

irqchip/armada-370-xp: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153333.330661455@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

irqchip/armada-370-xp: Make syscore_ops static

The armada_370_xp_mpic_syscore_ops structure is not exported or
declared anywhere. Fix the following warning by making it static:

drivers/irqchip/irq-armada-370-xp.c:544:20: warning: symbol 'armada_370_xp_mpic_syscore_ops' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Link: https://lkml.kernel.org/r/1465408533-13906-1-git-send-email-ben.dooks@codethink.co.uk
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip/armada-370-xp: Allow allocation of multiple MSIs

Add support for allocating multiple MSIs at the same time, so that the
MSI_FLAG_MULTI_PCI_MSI flag can be added to the msi_domain_info
structure.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1455115621-22846-6-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip/armada-370-xp: Use shorter names for irq_chip

In order to make the output of /proc/interrupts, use shorter names for
the irq_chip registered by the irq-armada-370-xp driver. Using capital
letters also matches better what is done for the GIC driver, which
uses just "GIC" as the irq_chip->name.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1455115621-22846-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip/armada-370-xp: Use PCI_MSI_DOORBELL_START where appropriate

As suggested by Gregory Clement, this commit adjusts the
irq-armada-370-xp driver to use the PCI_MSI_DOORBELL_START define in
the armada_370_xp_handle_msi_irq() function, rather than hardcoding
its value.

Suggested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1455115621-22846-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip/armada-370-xp: Use the generic MSI infrastructure

This commit moves the irq-armada-370-xp driver from using the
PCI-specific MSI infrastructure to the generic MSI infrastructure, to
which drivers are progressively converted.

In this hardware, the MSI controller is directly bundled inside the
interrupt controller, so we have a single Device Tree node to which
multiple IRQ domaines are attached: the wired interrupt domain and the
MSI interrupt domain. In order to ensure that they can be
differentiated, we have to force the bus_token of the wired interrupt
domain to be DOMAIN_BUS_WIRED. The MSI domain bus_token is
automatically set to the appropriate value by
pci_msi_create_irq_domain().

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1455115621-22846-3-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip/armada-370-xp: Fix regression by clearing IRQ_NOAUTOEN

Commit d17cab4451df1 ("irqchip: Kill off set_irq_flags usage") changed
the code of armada_370_xp_mpic_irq_map() from using set_irq_flags() to
irq_set_probe().

While the commit log seems to imply that there are no functional
changes, there are indeed functional changes introduced by this
commit: the IRQ_NOAUTOEN flag is no longer cleared. This functional
change causes a regression on Armada XP, which no longer works
properly after suspend/resume because per-CPU interrupts remain
disabled.

Due to how the hardware registers work, the irq-armada-370-xp cannot
simply save/restore a bunch of registers at suspend/resume to make
sure that the interrupts remain in the same state after
resuming. Therefore, it relies on the kernel to say whether the
interrupt is disabled or not, using the irqd_irq_disabled()
function. This was all working fine while the IRQ_NOAUTOEN flag was
cleared.

With the change introduced by Rob Herring in d17cab4451df1, the
IRQ_NOAUTOEN flag is now set for all interrupts. irqd_irq_disabled()
returns false for per-CPU interrupts, and therefore our per-CPU
interrupts are no longer re-enabled after resume.

This commit works around this problem by clearing again the
IRQ_NOAUTOEN flags, so that we are back to the situation we had before
commit d17cab4451df1. This work around is proposed as a minimal fix
for the problem, while a better long-term solution is being worked on.

Fixes: d17cab4451df1 "irqchip: Kill off set_irq_flags usage"
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1445435295-19956-1-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: armada-370-xp: Rework per-cpu interrupts handling

The MPIC driver currently has a list of interrupts to handle as per-cpu.

Since the timer, fabric and neta interrupts were the only per-cpu
interrupts in the system, we can now remove the switch and just check for
the hardware irq number to determine whether a given interrupt is per-cpu
or not.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

irqchip: Kill off set_irq_flags usage

set_irq_flags is ARM specific with custom flags which have genirq
equivalents. Convert drivers to use the genirq interfaces directly, so we
can kill off set_irq_flags. The translation of flags is as follows:

IRQF_VALID -> !IRQ_NOREQUEST
IRQF_PROBE -> !IRQ_NOPROBE
IRQF_NOAUTOEN -> IRQ_NOAUTOEN

For IRQs managed by an irqdomain, the irqdomain core code handles clearing
and setting IRQ_NOREQUEST already, so there is no need to do this in
.map() functions and we can simply remove the set_irq_flags calls. Some
users also modify IRQ_NOPROBE and this has been maintained although it
is not clear that is really needed. There appears to be a great deal of
blind copy and paste of this code.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Link: http://lkml.kernel.org/r/1440889285-5637-3-git-send-email-robh@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

genirq: Remove irq argument from irq flow handlers

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>

irqchip: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc

Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/1433391238-19471-11-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: Prepare for local stub header removal

The IRQCHIP_DECLARE macro moved to to 'include/linux/irqchip.h', so
the local irqchip.h became an empty shell, which solely includes
include/linux/irqchip.h

Include the global header in all irqchip drivers instead of the local
header, so we can remove it.

Signed-off-by: Joel Porquet <joel@porquet.org>
Cc: vgupta@synopsys.com
Cc: monstr@monstr.eu
Cc: ralf@linux-mips.org
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/1882096.X39jVG8e0D@joel-zenbook
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: Constify irq_domain_ops

The irq_domain_ops are not modified by the driver and the irqdomain core
code accepts pointer to a const data.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Link: http://lkml.kernel.org/r/1430139264-4362-2-git-send-email-k.kozlowski.k@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: armada-370-xp: Allow using wakeup source

On the Armada 370/XP SoCs, in standby mode the SoC stay powered and it
is possible to wake-up from any interrupt sources. This patch adds
flag to the MPIC irqchip driver to let linux know this.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1427724278-12379-5-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Enable the PMU interrupts

In order to let the Performance Monitoring Unit interrupts flowing in the MPIC,
we need to unmask these interrupts in the Coherency Fabric Local Interrupt Mask
Register.

Since this register is a CPU-local register, unmasking this interrupt needs to
be done on the boot CPU when the driver initializes, but also on the secondary
CPU when they are brought up.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1425379400-4346-4-git-send-email-maxime.ripard@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Introduce a is_percpu_irq() helper for readability

This commit introduces a helper function is_percpu_irq(), to be used
when interrupts are mapped to decide which ones are set as per CPU.

This change will allow to extend the list of per cpu interrupts in a less
intrusive fashion; also, it makes the code slightly more readable by keeping
a list of the per CPU interrupts.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1425379400-4346-3-git-send-email-maxime.ripard@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Initialize per cpu registers when CONFIG_SMP=N

The irqchip driver called armada_xp_mpic_smp_cpu_init() when CONFIG_SMP=Y
to initialize some per cpu registers. The function is called on each
CPU by calling it explicitly on the boot CPU and then using a CPU notifier
for the non boot CPUs.

This commit removes the CONFIG_SMP constrain, so the per cpu registers are
also initialized when CONFIG_SMP=N, which is the right thing to do.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1425379400-4346-2-git-send-email-maxime.ripard@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Fix chained per-cpu interrupts

On the Cortex-A9-based Armada SoCs, the MPIC is not the primary interrupt
controller. Yet, it still has to handle some per-cpu interrupt.

To do so, it is chained with the GIC using a per-cpu interrupt. However, the
current code only call irq_set_chained_handler, which is called and enable that
interrupt only on the boot CPU, which means that the parent per-CPU interrupt
is never unmasked on the secondary CPUs, preventing the per-CPU interrupt to
actually work as expected.

This was not seen until now since the only MPIC PPI users were the Marvell
timers that were not working, but not used either since the system use the ARM
TWD by default, and the ethernet controllers, that are faking there interrupts
as SPI, and don't really expect to have interrupts on the secondary cores
anyway.

Add a CPU notifier that will enable the PPI on the secondary cores when they
are brought up.

Cc: <stable@vger.kernel.org> # 3.15+
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1425378443-28822-1-git-send-email-maxime.ripard@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Add suspend/resume support

This commit adds suspend/resume support to the irqchip driver used on
Armada XP platforms (amongst others). It does so by adding a set of
suspend/resume syscore_ops, that will respectively save and restore
the necessary registers to ensure interrupts continue to work after
resume.

It is worth mentioning that the affinity is lost during a
suspend/resume cycle, because when a secondary CPU is brought
off-line, all interrupts that are assigned to this CPU in terms of
affinity gets re-assigned to a still running CPU. Therefore, right
before entering suspend, all interrupts are assigned to the boot CPU.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: linux-kernel@vger.kernel.org
Link: https://lkml.kernel.org/r/1416585613-2113-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

PCI/MSI: Rename mask/unmask_msi_irq treewide

The PCI/MSI irq chip callbacks mask/unmask_msi_irq have been renamed
to pci_msi_mask/unmask_irq to mark them PCI specific. Rename all usage
sites. The conversion helper functions are kept around to avoid
conflicts in next and will be removed after merging into mainline.

Coccinelle assisted conversion. No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: x86@kernel.org
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Murali Karicheri <m-karicheri2@ti.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Mohit Kumar <mohit.kumar@st.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Yijing Wang <wangyijing@huawei.com>

PCI/MSI: Rename write_msi_msg() to pci_write_msi_msg()

Rename write_msi_msg() to pci_write_msi_msg() to mark it as PCI
specific.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

PCI/MSI: Rename "struct msi_chip" to "struct msi_controller"

"msi_chip" isn't very descriptive, so rename it to "msi_controller". That
tells a little more about what it does and is already used in device tree
bindings.

No functional change.

[bhelgaas: changelog, change *only* the struct name so it's reviewable]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

irqchip: irq-armada-370-xp: Use proper return value for ->set_affinity()

The ->set_affinity() hook of 'struct irq_chip' is supposed to return
one of IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY. However, the code
currently simply returns 0. This patch fixes that by using
IRQ_SET_MASK_OK, which tells the IRQ core that it is responsible for
updating irq_data.affinity.

Note that this patch does not cause any change to the compiled code,
as IRQ_SET_MASK_OK has the value 0. This is therefore just a simple
cleanup.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1414151970-6626-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Fix MPIC interrupt handling

In both Armada-375 and Armada-38x MPIC interrupts should be identified by
reading cause register multiplied by the interrupt mask.

A lack of above mentioned multiplication resulted in a bug, caused by the
fact that in Armada-375 and Armada-38x some of the interrupts
(e.g. network interrupts) can be handled either as a GIC or MPIC interrupts.
Therefore during MPIC interrupts handling, cause register shows hits from
interrupts even if they are masked for MPIC but unmasked for a GIC.

This resulted in 'bad IRQ' error, because masked MPIC interrupt without
registered interrupt handler, was trying to be handled during interrupt
handling procedure of some other unmasked MPIC interrupt (e.g. local timer
irq).

This commit fixes that by ensuring that during MPIC interrupt handling only
interrupts that are unmasked for MPIC are processed.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Fixes: bc69b8adfe22 ("irqchip: armada-370-xp: Setup a chained handler for the MPIC")
Cc: <stable@vger.kernel.org> # v3.15+
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1411643839-64925-3-git-send-email-jaz@semihalf.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Fix MSI interrupt handling

The MSI interrupts use the 16 high doorbells, which are notified by using IRQ1
of the main interrupt controller.

The MSI interrupts were handled correctly for Armada-XP and Armada-370 but not
for Armada-375 and Armada-38x, which use chained handler for the MPIC.

This commit fixes that by checking proper interrupt number in chained handler
for the MPIC.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Fixes: bc69b8adfe22 ("irqchip: armada-370-xp: Setup a chained handler for the MPIC")
Cc: <stable@vger.kernel.org> # v3.15+
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1411643839-64925-2-git-send-email-jaz@semihalf.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Remove arch_msi_check_device()

Move MSI checks from arch_msi_check_device() to arch_setup_msi_irqs().
This makes the code more compact and allows removing
arch_msi_check_device() from generic MSI code.

Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
CC: Thomas Gleixner <tglx@linutronix.de>

irqchip: armada-370-xp: Convert to handle_domain_irq

Use the new handle_domain_irq method to handle interrupts.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1409047421-27649-7-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Mask all interrupts during initialization.

Until now, the irq-armada-370-xp irqchip driver was not masking all
interrupts at initialization. While in most cases this is not a
problem because the bootloader has probably masked all interrupts, it
becomes a problem when you use kexec: you're in kernel A, with many
interrupts enabled, and then kexec into kernel B, without going
through the bootloader. So during the boot process, if an interrupt
occurs while the corresponding driver has not been loaded, you would
get spurious interrupts.

This commit fixes that by ensuring all interrupts are properly masked
when the irqchip driver is initialized. Note that interrupt masking
takes place at two level: at the global level (main_int_base) and at
the per-CPU level (per_cpu_int_base).

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1401481098-23326-6-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: irq-armada-370-xp: Use cpu notifier to initialize secondary CPUs

Some irqchip initialization must be done on secondary CPUs. On mvebu
platforms, this is currently achieved by having the
arch/arm/mach-mvebu/platsmp.c code directly call into a function
exported by the irqchip driver, which isn't really nice.

This commit changes this by using the same solution as the one used in
the GIC driver: the irqchip driver registers a CPU notifier, which is
used to do the secondary CPU IRQ initialization. This way, the irqchip
driver is completely autonomous, and the function no longer needs to
be exposed from the irqchip driver to the SoC code.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-6-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: irq-armada-370-xp: Do the set_smp_cross_call() in the driver

Instead of having the SoC code in arch/arm/mach-mvebu/platsmp.c do the
set_smp_cross_call() to register the IPI-triggering function, it makes
more sense to do exactly what the GIC driver is doing: let the irqchip
driver do it. This way, it avoids having to expose the
armada_mpic_send_doorbell() function between the irqchip driver and
the SoC code.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armanda: Sanitize set_irq_affinity()

The set_irq_affinity() function has two issues:

1) It has no protection against selecting an offline cpu from the
given mask.

2) It pointlessly restricts the affinity masks to have a single cpu
set. This collides with the irq migration code of arm.

irq affinity is set to core 3
core 3 goes offline

migration code sets mask to cpu_online_mask and calls the
irq_set_affinity() callback of the irq_chip which fails due to bit
0,1,2 set.

So instead of doing silly for_each_cpu() loops just pick any bit of
the mask which intersects with the online mask.

Get rid of fiddling with the default_irq_affinity as well.

[ Gregory: Fixed the access to the routing register ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/20140304203101.088889302@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: armada-370-xp: Fix releasing of MSIs

Store the value of d->hwirq in a local variable as the real value is wiped out
by calling irq_dispose_mapping. Without this patch, the armada_370_xp_free_msi
function would always free MSI#0, no matter what was passed to it.

Fixes: 31f614edb726fcc4d5aa0f2895fbdec9b04a3ca4 ('irqchip: armada-370-xp: implement MSI support')
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Neil Greatorex <neil@fatboyfat.co.uk>
Link: https://lkml.kernel.org/r/1397823593-1932-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397823593-1932-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: implement the ->check_device() msi_chip operation

Until now, we were leaving the ->check_device() msi_chip operation
empty, which leads the PCI core to believe that we support both MSI
and MSI-X. In fact, we do not support MSI-X, so we have to tell this
to the PCI core by providing an implementation of this operation.

Fixes: 31f614edb726fcc4d5aa0f2895fbdec9b04a3ca4 ('irqchip: armada-370-xp: implement MSI support')
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397823593-1932-3-git-send-email-thomas.petazzoni@free-electrons.com
Tested-by: Neil Greatorex <neil@fatboyfat.co.uk>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: fix invalid cast of signed value into unsigned variable

The armada_370_xp_alloc_msi() function returns a signed int, which is
negative on error. However, we store the return value into an
irq_hw_number_t, which is unsigned. Therefore, we actually never test
if armada_370_xp_alloc_msi() returns an error or not, which may lead
us to use hwirq numbers of as 0xffffffe4 (when
armada_370_xp_alloc_msi() returns -ENOSPC).

This commit fixes that by storing the return value of
armada_370_xp_alloc_msi() in a signed variable.

Fixes: 31f614edb726fcc4d5aa0f2895fbdec9b04a3ca4 ('irqchip: armada-370-xp: implement MSI support')
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397823593-1932-2-git-send-email-thomas.petazzoni@free-electrons.com
Tested-by: Neil Greatorex <neil@fatboyfat.co.uk>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: Remove asmlinkage from static functions

LTO patches add __visible to the asmlinkage define, causing
compilation warnings like:

drivers/irqchip/irq-gic.c:283:1: warning: 'externally_visible'
attribute have effect only on public objects [-Wattributes]

Drop asmlinkage here to avoid such warnings.

Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: khilman@linaro.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Josh Cartwright <joshc@codeaurora.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1393980030-17770-1-git-send-email-sboyd@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: armada-370-xp: Setup a chained handler for the MPIC

The new Armada 375 and Armada 38x Marvell SoCs are based on Cortex-A9
CPU cores and use the ARM GIC as their main interrupt controller.
However, for various purposes (wake-up from suspend, MSI interrupts),
they have kept a separate MPIC interrupt controller, acting as a slave
to the GIC. This MPIC was already used as the primary controller on
previous Marvell SoCs, so this commit extends the existing driver to
allow the MPIC to be used as a GIC slave.

Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: Add helper for the MSI IRQ handling

Introduce a helper function to handle the MSI interrupts. This makes
the code more readable. In addition, this will allow to introduce a
chained IRQ handler mechanism, which is needed in situations where the
MPIC is used as a slave to another interrupt controller.

Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

ARM: mvebu: fix compilation warning on Armada 370 (i.e. non-SMP)

The following appears during compilation for an Armada 370 target
because 'irq_controller_lock' is used only when CONFIG_SMP is
enabled:

drivers/irqchip/irq-armada-370-xp.c:62:8: warning: 'irq_controller_lock' defined but not used [-Wunused-variable]

Fix that warning by moving declaration of 'irq_controller_lock'
inside existing #ifdef.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: fix MSI race condition

In the Armada 370/XP driver, when we receive an IRQ 1, we read the
list of doorbells that caused the interrupt from register
ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS. This gives the list of MSIs that
were generated. However, instead of acknowledging only the MSIs that
were generated, we acknowledge *all* the MSIs, by writing
~MSI_DOORBELL_MASK in the ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register.

This creates a race condition: if a new MSI that isn't part of the
ones read into the temporary "msimask" variable is fired before we
acknowledge all MSIs, then we will simply loose it.

It is important to mention that this ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS
register has the following behavior: "A CPU write of 0 clears the bits
in this field. A CPU write of 1 has no effect". This is what allows us
to simply write ~msimask to acknoledge the handled MSIs.

Notice that the same problem is present in the IPI implementation, but
it is fixed as a separate patch, so that this IPI fix can be pushed to
older stable versions as appropriate (all the way to 3.8), while the
MSI code only appeared in 3.13.

Signed-off-by: Lior Amsalem <alior@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: fix IPI race condition

In the Armada 370/XP driver, when we receive an IRQ 0, we read the
list of doorbells that caused the interrupt from register
ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS. This gives the list of IPIs that
were generated. However, instead of acknowledging only the IPIs that
were generated, we acknowledge *all* the IPIs, by writing
~IPI_DOORBELL_MASK in the ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register.

This creates a race condition: if a new IPI that isn't part of the
ones read into the temporary "ipimask" variable is fired before we
acknowledge all IPIs, then we will simply loose it. This is causing
scheduling hangs on SMP intensive workloads.

It is important to mention that this ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS
register has the following behavior: "A CPU write of 0 clears the bits
in this field. A CPU write of 1 has no effect". This is what allows us
to simply write ~ipimask to acknoledge the handled IPIs.

Notice that the same problem is present in the MSI implementation, but
it will be fixed as a separate patch, so that this IPI fix can be
pushed to older stable versions as appropriate (all the way to 3.8),
while the MSI code only appeared in 3.13.

Signed-off-by: Lior Amsalem <alior@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: stable@vger.kernel.org # v3.8+
Fixes: 344e873e5657e8dc0 'arm: mvebu: Add IPI support via doorbells'
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: implement MSI support

This commit introduces the support for the MSI interrupts in the
armada-370-xp interrupt controller driver. It registers an MSI chip to
the MSI chip registry, which will be used by the Marvell PCIe host
controller driver.

The MSI interrupts use the 16 high doorbells, and are therefore
notified using IRQ1 of the main interrupt controller.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: properly request resources

Instead of using of_iomap(), we now use of_address_to_resource(),
request_mem_region() and ioremap(). This allows the corresponding I/O
regions to be properly requested and visible in /proc/iomem.

The main motivation for this change is that the introduction of the
MSI support requires us to get the physical address of the main
interrupt controller registers, so we will need the corresponding
'struct resource' anyway.

We also take this opportunity to change a panic() to BUG_ON(), in
order to be consistent with the rest of the driver.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Daniel Price <daniel.price@gmail.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: slightly cleanup irq controller driver

In preparation for the introduction of MSI support in the IRQ
controller driver, we clarify the implementation of IPI using
additional defines for the manipulation of doorbells. Just like IPIs
are implemented using doorbells, MSIs will also use doorbells, so it
makes sense to do this preparatory cleanup first.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: armada-370-xp: move IRQ handler to avoid forward declaration

If we move the IRQ handler function above the initialization function,
we avoid a forward declaration. This wasn't done as part of the
previous commit, in order to increase the readibility of the previous
commit, who was also moving the IRQ controller driver from arch/arm to
drivers/irqchip.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: move IRQ driver for Armada 370/XP

When the Marvell Armada 370/XP support was included in the kernel, the
drivers/irqchip/ directory didn't exist and the minimal infrastructure
in it also didn't exist. Now that we have those things in place, we
move the Armada 370/XP IRQ controller driver from
arch/arm/mach-mvebu/irq-armada-370-xp.c to
drivers/irqchip/irq-armada-370-xp.c.

Note in order to reduce code movement and therefore ease the review of
this patch, we intentionally introduce a forward declaration of
armada_370_xp_handle_irq(). It is in fact not needed because this
handler can now simply be implemented before
armada_370_xp_mpic_of_init(). That will be done in the next commit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>