tree c9b04b65130b96654d275cb550568748a4087f08
parent 2cccbb368a2bf27d98cf36bb424fbbf5572c0fab
author Christoffer Dall <christoffer.dall@linaro.org> 1470240224 +0200
committer Christoffer Dall <christoffer.dall@linaro.org> 1471294820 +0200

KVM: arm64: vgic-its: Make updates to propbaser/pendbaser atomic

There are two problems with the current implementation of the MMIO
handlers for the propbaser and pendbaser:

First, the write to the value itself is not guaranteed to be an atomic
64-bit write so two concurrent writes to the structure field could be
intermixed.

Second, because we do a read-modify-update operation without any
synchronization, if we have two 32-bit accesses to separate parts of the
register, we can loose one of them.

By using the atomic cmpxchg64 we should cover both issues above.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>