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Commit 19fb5dab authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Greg Kroah-Hartman
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x86/msi: Force affinity setup before startup



commit ff363f48 upstream.

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: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.886722080@linutronix.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4e52a4fe
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