irqchip/sifive-plic: Avoid interrupt ID 0 handling during suspend/resume

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[ Upstream commit f75e07bf52 ]

According to the PLIC specification[1], global interrupt sources are
assigned small unsigned integer identifiers beginning at the value 1.
An interrupt ID of 0 is reserved to mean "no interrupt".

The current plic_irq_resume() and plic_irq_suspend() functions incorrectly
start the loop from index 0, which accesses the register space for the
reserved interrupt ID 0.

Change the loop to start from index 1, skipping the reserved
interrupt ID 0 as per the PLIC specification.

This prevents potential undefined behavior when accessing the reserved
register space during suspend/resume cycles.

Fixes: e80f0b6a2c ("irqchip/irq-sifive-plic: Add syscore callbacks for hibernation")
Co-developed-by: Jia Wang <wangjia@ultrarisc.com>
Signed-off-by: Jia Wang <wangjia@ultrarisc.com>
Co-developed-by: Charles Mirabile <cmirabil@redhat.com>
Signed-off-by: Charles Mirabile <cmirabil@redhat.com>
Signed-off-by: Lucas Zampieri <lzampier@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://github.com/riscv/riscv-plic-spec/releases/tag/1.0.0
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Lucas Zampieri 2025-09-23 15:43:19 +01:00 • committed by Greg Kroah-Hartman

parent 91f66152f5

commit 9d0ac18eb5

1 changed files with 4 additions and 2 deletions

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drivers/irqchip/irq-sifive-plic.c

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