irqchip: irq-xtensa-mx: include header for missing prototype

Add <linux/irqchips/xtensa-mx.h> to provide the function prototype to
prevent a build warning:

drivers/irqchip/irq-xtensa-mx.c:166:12: warning: no previous prototype for 'xtensa_mx_init_legacy' [-Wmissing-prototypes]
166 | int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent)

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Message-Id: <20230920052139.10570-10-rdunlap@infradead.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

irqchip/xtensa-mx: Fix initial IRQ affinity in non-SMP setup

When irq-xtensa-mx chip is used in non-SMP configuration its
irq_set_affinity callback is not called leaving IRQ affinity set empty.
As a result IRQ delivery does not work in that configuration.
Initialize IRQ affinity of the xtensa MX interrupt distributor to CPU 0
for all external IRQ lines.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220426161912.1113784-1-jcmvbkbc@gmail.com

irqchip: irq-xtensa-mx: fix initial IRQ affinity

When irq-xtensa-mx chip is used in non-SMP configuration its
irq_set_affinity callback is not called leaving IRQ affinity set empty.
As a result IRQ delivery does not work in that configuration.
Initialize IRQ affinity of the xtensa MX interrupt distributor to CPU 0
for all external IRQ lines.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

drivers/irqchip: xtensa-mx: fix mask and unmask

xtensa_irq_mask and xtensa_irq_unmask don't do the right thing when
called for the first two external IRQs. Treat these IRQs as per-CPU
IRQs.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

drivers/irqchip: xtensa: add warning to irq_retrigger

XEA2 and MX PIC can only retrigger software interrupts. Issue a warning
if an interrupt of any other type is retriggered.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: clean up WSR*/RSR*/get_sr/set_sr

WSR and RSR are too generic and collide with other macro definitions in
the kernel causing warnings in allmodconfig builds. Drop WSR and RSR
macros and WSR_* and RSR_* variants. Change get_sr and set_sr to
xtensa_get_sr and xtensa_set_sr. Fix up users.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: drop variant IRQ support

If an xtensa core provides an additional IRQ controller it should be
treated as a separate piece of hardware and be driven by an irqchip
driver.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

irqchip/xtensa-mx: Report that effective affinity is a single target

The xtensa-mx 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/20170818083925.10108-13-marc.zyngier@arm.com

xtensa: don't use linux IRQ #0

Linux IRQ #0 is reserved for error reporting and may not be used.
Increase NR_IRQS for one additional slot and increase
irq_domain_add_legacy parameter first_irq value to 1, so that linux
IRQ #0 is not associated with hardware IRQ #0 in legacy IRQ domains.
Introduce macro XTENSA_PIC_LINUX_IRQ for static translation of xtensa
PIC hardware IRQ # to linux IRQ #. Use this macro in XTFPGA platform
data definitions.

This fixes inability to use hardware IRQ #0 in configurations that don't
use device tree and allows for non-identity mapping between linux IRQ #
and hardware IRQ #.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

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: xtensa: Select only an online cpu

The user space interface does not filter out offline cpus. It merily
verifies that the mask contains at least one online cpu. So the
selector in the irq chip implementation needs to make sure to pick
only an online cpu because otherwise:

Offline Core 1
Set affinity to 0xe
Selector will pick first set bit, i.e. core 1

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: xtensa <linux-xtensa@linux-xtensa.org>

xtensa: add MX irqchip

MX is an interrupt distributor used in some SMP-capable xtensa
configurations.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>