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Sudeep Holla authored
commit 3d8afe30 upstream. The arm64 interrupt migration code on cpu offline calls irqchip.irq_set_affinity() with the argument force=true. Originally this argument had no effect because it was not used by any interrupt chip driver and there was no semantics defined. This changed with commit 01f8fa4f ("genirq: Allow forcing cpu affinity of interrupts") which made the force argument useful to route interrupts to not yet online cpus without checking the target cpu against the cpu online mask. The following commit ffde1de6 ("irqchip: gic: Support forced affinity setting") implemented this for the GIC interrupt controller. As a consequence the cpu offline irq migration fails if CPU0 is offlined, because CPU0 is still set in the affinity mask and the validation against cpu online mask is skipped to the force argument being true. The following first_cpu(mask) selection always selects CPU0 as the target. Commit 601c9421("arm64: use cpu_online_mask when using forced irq_set_affinity") intended to fix the above mentioned issue but introduced another issue where affinity can be migrated to a wrong CPU due to unconditional copy of cpu_online_mask. As with for arm, solve the issue by calling irq_set_affinity() with force=false from the CPU offline irq migration code so the GIC driver validates the affinity mask against CPU online mask and therefore removes CPU0 from the possible target candidates. Also revert the changes done in the commit 601c9421 as it's no longer needed. Tested on Juno platform. Fixes: 601c9421("arm64: use cpu_online_mask when using forced irq_set_affinity") Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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