irqchip/irq-xtensa-pic: Clean up

- get rid of the cached_irq_mask variable
- use BIT() macro instead of bit shifts
- drop .disable and .enable as they are equivalent to the default
implementations

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20231208163857.82644-1-jcmvbkbc@gmail.com

irqchip/xtensa-pic: Include header for xtensa_pic_init_legacy()

The declaration for this function is not included, which leads to a harmless warning:

drivers/irqchip/irq-xtensa-pic.c:91:12: error: no previous prototype for 'xtensa_pic_init_legacy' [-Werror=missing-prototypes]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230810123404.1222332-1-arnd@kernel.org

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>

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>

xtensa: move built-in PIC to drivers/irqchip

Extract xtensa built-in interrupt controller implementation from
xtensa/kernel/irq.c and move it to other irqchips, providing way to
instantiate it from the device tree.

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