linux-stable.git/include/linux/irq.h, branch v6.15.2

genirq: Introduce irq_can_move_in_process_context()

2025-02-20T14:19:26+00:00

Interrupt controller drivers which enable CONFIG_GENERIC_PENDING_IRQ
require to know whether an interrupt can be moved in process context or not
to decide whether they need to invoke the work around for non-atomic MSI
updates or not.

This information can be retrieved via irq_can_move_pcntxt(). That helper
requires access to the top-most interrupt domain data, but the driver which
requires this is usually further down in the hierarchy.

Introduce irq_can_move_in_process_context() which retrieves that
information from the top-most interrupt domain data.

[ tglx: Massaged change log ]

Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20250217085657.789309-6-apatel@ventanamicro.com

genirq: Introduce common irq_force_complete_move() implementation

2025-02-20T14:19:26+00:00

CONFIG_GENERIC_PENDING_IRQ requires an architecture specific implementation
of irq_force_complete_move() for CPU hotplug. At the moment, only x86
implements this unconditionally, but for RISC-V irq_force_complete_move()
is only needed when the RISC-V IMSIC driver is in use and not needed
otherwise.

To allow runtime configuration of this mechanism, introduce a common
irq_force_complete_move() implementation in the interrupt core code, which
only invokes the completion function, when a interrupt chip in the
hierarchy implements it.

Switch X86 over to the new mechanism. No functional change intended.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Anup Patel 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20250217085657.789309-5-apatel@ventanamicro.com

genirq: Remove IRQ_MOVE_PCNTXT and related code

2025-01-15T20:38:53+00:00

Now that x86 is converted over to use the IRQCHIP_MOVE_DEFERRED flags,
remove IRQ*_MOVE_PCNTXT and related code.

Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241210103335.626707225@linutronix.de

genirq: Provide IRQCHIP_MOVE_DEFERRED

2025-01-15T09:56:22+00:00

The logic of GENERIC_PENDING_IRQ is backwards for historical reasons. Most
interrupt controllers allow to move the interrupt from arbitrary
contexts. If GENERIC_PENDING_IRQ is enabled by an architecture to support a
chip, which requires the affinity change to happen in interrupt context,
all other chips have to be marked with IRQF_MOVE_PCNTXT.

That's tedious and there is no real good reason for the extra flags in the
irq descriptor and the irq data status fields. In fact the decision whether
interrupts can be moved in arbitrary context or not is a property of the
interrupt chip.

To simplify adoption for RISC-V provide a new mechanism which is enabled
via a config switch and allows to add a flag to irq_chip::flags to request
that interrupt affinity changes are deferred. Setting the top level chip of
an interrupt evaluates the flag and maps it into the existing logic.

The config switch and the various PCNTXT flags are temporary until x86 is
converted over to this scheme. This intermediate step also allows trivial
backporting of the mechanism to plug the affinity change race of various
RISC-V interrupt controllers.

Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241210103335.500314436@linutronix.de

kexec: Consolidate machine_kexec_mask_interrupts() implementation

2024-12-11T19:32:34+00:00

Consolidate the machine_kexec_mask_interrupts implementation into a common
function located in a new file: kernel/irq/kexec.c. This removes duplicate
implementations from architecture-specific files in arch/arm, arch/arm64,
arch/powerpc, and arch/riscv, reducing code duplication and improving
maintainability.

The new implementation retains architecture-specific behavior for
CONFIG_GENERIC_IRQ_KEXEC_CLEAR_VM_FORWARD, which was previously implemented
for ARM64. When enabled (currently for ARM64), it clears the active state
of interrupts forwarded to virtual machines (VMs) before handling other
interrupt masking operations.

Signed-off-by: Eliav Farber 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241204142003.32859-2-farbere@amazon.com

genirq: Remove irq_chip_regs:: Polarity

2024-08-08T15:15:02+00:00

The polarity member of struct irq_chip_regs is unused. Remove it along
with its kernel-doc.

Found by https://github.com/jirislaby/clang-struct.

Signed-off-by: Jiri Slaby (SUSE) 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20240808104118.430670-3-jirislaby@kernel.org

genirq: Remove unused irq_chip_generic:: {type,polarity}_cache

2024-08-08T15:15:02+00:00

The type_cache and polarity_cache members of struct irq_chip_generic are
unused. Remove them both along with their kernel-doc.

Found by https://github.com/jirislaby/clang-struct.

Signed-off-by: Jiri Slaby (SUSE) 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20240808104118.430670-2-jirislaby@kernel.org

irqdomain: Make build work for CONFIG_GENERIC_IRQ_CHIP=n

2024-06-17T18:46:39+00:00

ld: kernel/irq/irqdomain.o: in function `irq_domain_instantiate':
kernel/irq/irqdomain.c:296:(.text+0x10dd): undefined reference to `irq_domain_alloc_generic_chips'
ld: kernel/irq/irqdomain.c:313:(.text+0x1218): undefined reference to `irq_domain_remove_generic_chips'
ld: kernel/irq/irqdomain.o: in function `irq_domain_remove':
kernel/irq/irqdomain.c:349:(.text+0x1ddf): undefined reference to `irq_domain_remove_generic_chips'

Provide the required stubs.

Fixes: e6f67ce32e8e ("irqdomain: Add support for generic irq chips creation before publishing a domain")
Reported-by: Borislav Betkov 
Signed-off-by: Thomas Gleixner

genirq/generic_chip: Introduce init() and exit() hooks

2024-06-17T13:48:14+00:00

Most of generic chip drivers need to perform some more additional
initializations on the generic chips allocated before they can be fully
ready.

These additional initializations need to be performed before the IRQ
domain is published to avoid a race condition between IRQ consumers and
suppliers.

Introduce the init() hook to perform these initializations at the right
place just after the generic chip creation. Also introduce the exit() hook
to allow reverting operations done by the init() hook just before the
generic chip is destroyed.

Suggested-by: Thomas Gleixner 
Signed-off-by: Herve Codina 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240614173232.1184015-15-herve.codina@bootlin.com

genirq/generic_chip: Introduce irq_domain_{alloc,remove}_generic_chips()

2024-06-17T13:48:14+00:00

The existing __irq_alloc_domain_generic_chips() uses a bunch of parameters
to describe the generic chips that need to be allocated.

Adding more parameters and wrappers to hide new parameters in the existing
code leads to more and more code without any relevant values and without
any flexibility.

Introduce irq_domain_alloc_generic_chips() where the generic chips
description is done using the irq_domain_chip_generic_info structure
instead of the bunch of parameters to allow flexibility and easy evolution.

Also introduce irq_domain_remove_generic_chips() to revert the operations
done by irq_domain_alloc_generic_chips().

Suggested-by: Thomas Gleixner 
Signed-off-by: Herve Codina 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20240614173232.1184015-14-herve.codina@bootlin.com