]> git.baikalelectronics.ru Git - kernel.git/commit
x86/msi: Force affinity setup before startup
authorThomas Gleixner <tglx@linutronix.de>
Thu, 29 Jul 2021 21:51:50 +0000 (23:51 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 18 Aug 2021 06:57:02 +0000 (08:57 +0200)
commita19eb9342aaaa2540dc683b10dd04aeb217bb2bf
tree631e05848431216176e7319c4e1ac3d960385dca
parenta520dc5f4170612becb79c5ff199fd6d45b39c1b
x86/msi: Force affinity setup before startup

commit ff363f480e5997051dd1de949121ffda3b753741 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: fdd62585f1cd ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kernel/apic/msi.c