Lorenzo Pieralisi 5cb1b6dab2 irqchip/gic-v5: Add GICv5 IRS/SPI support
The GICv5 Interrupt Routing Service (IRS) component implements
interrupt management and routing in the GICv5 architecture.

A GICv5 system comprises one or more IRSes, that together
handle the interrupt routing and state for the system.

An IRS supports Shared Peripheral Interrupts (SPIs), that are
interrupt sources directly connected to the IRS; they do not
rely on memory for storage. The number of supported SPIs is
fixed for a given implementation and can be probed through IRS
IDR registers.

SPI interrupt state and routing are managed through GICv5
instructions.

Each core (PE in GICv5 terms) in a GICv5 system is identified with
an Interrupt AFFinity ID (IAFFID).

An IRS manages a set of cores that are connected to it.

Firmware provides a topology description that the driver uses
to detect to which IRS a CPU (ie an IAFFID) is associated with.

Use probeable information and firmware description to initialize
the IRSes and implement GICv5 IRS SPIs support through an
SPI-specific IRQ domain.

The GICv5 IRS driver:

- Probes IRSes in the system to detect SPI ranges
- Associates an IRS with a set of cores connected to it
- Adds an IRQchip structure for SPI handling

SPIs priority is set to a value corresponding to the lowest
permissible priority in the system (taking into account the
implemented priority bits of the IRS and CPU interface).

Since all IRQs are set to the same priority value, the value
itself does not matter as long as it is a valid one.

Co-developed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Co-developed-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Timothy Hayes <timothy.hayes@arm.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250703-gicv5-host-v7-21-12e71f1b3528@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-07-08 18:35:51 +01:00
2022-09-28 09:02:20 +02:00
2025-02-19 14:53:27 -07:00
2025-06-22 13:30:08 -07:00
2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
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