[PATCH v2 0/4] irqchip/gic: Generalize use of HW-based retriggering

From: Marc Zyngier
Date: Thu Sep 03 2020 - 14:32:33 EST


Valentin recently pointed out that that relying on SW-based retrigger
with any of the GIC interrupt controllers is both inefficient and
slightly broken, as it messes the GIC's own state machine.

For this to work with the hierarchical irqchip model that the GIC
uses, we need check_irq_resend grow an understanding of hierarchies,
something it has been lacking for some time.

The 3 other patches simply implement the HW resend callbacks, and
finally prevent any SW resend for the GICs.

Unless anyone objects, I plan to take this into 5.10.

* From v1:
- Dropped most of the patches in favour of a teaching the core
kernel to use irq_chip_retriger_hierarchy()

Marc Zyngier (2):
genirq: Walk the irq_data hierarchy when resending an interrupt
irqchip/git-v3-its: Implement irq_retrigger callback for
device-triggered LPIs

Valentin Schneider (2):
irqchip/gic-v2, v3: Implement irq_chip->irq_retrigger()
irqchip/gic-v2, v3: Prevent SW resends entirely

drivers/irqchip/irq-gic-v3-its.c | 6 ++++++
drivers/irqchip/irq-gic-v3.c | 12 +++++++++++-
drivers/irqchip/irq-gic.c | 12 +++++++++++-
kernel/irq/resend.c | 15 +++++++++++++--
4 files changed, 41 insertions(+), 4 deletions(-)

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2.28.0