x86/msi: Force affinity setup before startup
The X86 MSI mechanism cannot handle interrupt affinity changes safely after startup other than from an interrupt handler, unless interrupt remapping is enabled. The startup sequence in the generic interrupt code violates that assumption. Mark the irq chips with the new IRQCHIP_AFFINITY_PRE_STARTUP flag so that the default interrupt setting happens before the interrupt is started up for the first time. While the interrupt remapping MSI chip does not require this, there is no point in treating it differently as this might spare an interrupt to a CPU which is not in the default affinity mask. For the non-remapping case go to the direct write path when the interrupt is not yet started similar to the not yet activated case. Fixes: 18404756 ("genirq: Expose default irq affinity mask (take 3)") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.886722080@linutronix.de
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