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: 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/bcm2835: Quiesce IRQs left enabled by bootloader

Per the spec, the BCM2835's IRQs are all disabled when coming out of
power-on reset. Its IRQ driver assumes that's still the case when the
kernel boots and does not perform any initialization of the registers.
However the Raspberry Pi Foundation's bootloader leaves the USB
interrupt enabled when handing over control to the kernel.

Quiesce IRQs and the FIQ if they were left enabled and log a message to
let users know that they should update the bootloader once a fixed
version is released.

If the USB interrupt is not quiesced and the USB driver later on claims
the FIQ (as it does on the Raspberry Pi Foundation's downstream kernel),
interrupt latency for all other peripherals increases and occasional
lockups occur. That's because both the FIQ and the normal USB interrupt
fire simultaneously:

On a multicore Raspberry Pi, if normal interrupts are routed to CPU 0
and the FIQ to CPU 1 (hardcoded in the Foundation's kernel), then a USB
interrupt causes CPU 0 to spin in bcm2836_chained_handle_irq() until the
FIQ on CPU 1 has cleared it. Other peripherals' interrupts are starved
as long. I've seen CPU 0 blocked for up to 2.9 msec. eMMC throughput
on a Compute Module 3 irregularly dips to 23.0 MB/s without this commit
but remains relatively constant at 23.5 MB/s with this commit.

The lockups occur when CPU 0 receives a USB interrupt while holding a
lock which CPU 1 is trying to acquire while the FIQ is temporarily
disabled on CPU 1. At best users get RCU CPU stall warnings, but most
of the time the system just freezes.

Fixes: 89214f009c1d ("ARM: bcm2835: add interrupt controller driver")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/f97868ba4e9b86ddad71f44ec9d8b3b7d8daa1ea.1582618537.git.lukas@wunner.de

irqchip: bcm283x: Switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.

Cc: Simon Arlott <simon@arlott.org>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip: Convert to using %pOF instead of full_name

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Lee Jones <lee@kernel.org>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-tegra@vger.kernel.org
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Alexandre Torgue <alexandre.torgue@st.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip: bcm2835: Avoid arch/arm-specific handle_IRQ

With commit

76ba59f8366f genirq: Add irq_domain-aware core IRQ handler

architecture-specific irq handlers are no longer necessary. Update the bcm2835
irq driver to use the core irq handler. As a bonus, this allows the driver to
support arm64 as well.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Link: https://lkml.kernel.org/r/1464728727-16300-1-git-send-email-eric@anholt.net
[jac reworded commit message for clarity]
Signed-off-by: Jason Cooper <jason@lakedaemon.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/bcm2835: Add support for being used as a second level controller

The BCM2836 (Raspberry Pi 2) uses two levels of interrupt handling
with the CPU-local interrupts being the root, so we need to register
ours as chained off of the CPU's local interrupt.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: Lee Jones <lee@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1438902033-31477-3-git-send-email-eric@anholt.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ

For BCM2836, we want to chain into this IRQ chip from the root
controller, and for chaining we need to do something else instead of
handle_IRQ() once we have decoded the IRQ.

Note that this changes the behavior a little bit: Previously for a
non-shortcut IRQ, we'd loop reading and handling the second level IRQ
status until it was cleared before returning to the loop reading the
top level IRQ status (Note that the top level bit is just an OR of the
low level bits). For the expected case of just one interrupt to be
handled, this was an extra register read, so we're down from 4 to 3
reads.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: Lee Jones <lee@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1438902033-31477-2-git-send-email-eric@anholt.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: Appropriate __init annotation for const data

Init data marked const should be annotated with __initconst for
correctness and not __initdata. And for those already __initconst,
they should be qualified as const at the compiler level too.
This also fixes LTO builds that otherwise fail with section mismatch
errors.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1507241511551.1806@knanqh.ubzr
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: 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: bcm2835: Convert to use IRQCHIP_DECLARE macro

This patch converts irq-bcm2835 driver to use the new IRQCHIP_DECLARE and
irqchip_init.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: Simon Arlott <simon@fire.lp0.eu>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip: irq-bcm2835: Add terminating entry for of_device_id table

The of_device_id table is supposed to be zero-terminated.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

ARM: bcm2835: add interrupt controller driver

The BCM2835 contains a custom interrupt controller, which supports 72
interrupt sources using a 2-level register scheme. The interrupt
controller, or the HW block containing it, is referred to occasionally
as "armctrl" in the SoC documentation, hence the symbol naming in the
code.

This patch was extracted from git://github.com/lp0/linux.git branch
rpi-split as of 2012/09/08, and modified as follows:

* s/bcm2708/bcm2835/.
* Modified device tree vendor prefix.
* Moved implementation to drivers/irchip/.
* Added devicetree documentation, and hence removed list of IRQs from
bcm2835.dtsi.
* Changed shift in MAKE_HWIRQ() and HWIRQ_BANK() from 8 to 5 to reduce
the size of the hwirq space, and pass the total size of the hwirq space
to irq_domain_add_linear(), rather than just the number of valid hwirqs;
the two are different due to the hwirq space being sparse.
* Added the interrupt controller DT node to the top-level of the DT,
rather than nesting it inside a /axi node. Hence, changed the reg value
since /axi had a ranges property. This seems simpler to me, but I'm not
sure if everyone will like this change or not.
* Don't set struct irq_domain_ops.map = irq_domain_simple_map, hence
removing the need to patch include/linux/irqdomain.h or
kernel/irq/irqdomain.c.
* Simplified armctrl_of_init() using of_iomap().
* Removed unused IS_VALID_BANK()/IS_VALID_IRQ() macros.
* Renamed armctrl_handle_irq() to prevent possible symbol clashes.
* Made armctrl_of_init() static.
* Removed comment "Each bank is registered as a separate interrupt
controller" since this is no longer true.
* Removed FSF address from license header.
* Added my name to copyright header.

Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Dom Cobley <dc4@broadcom.com>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>