On Mon, 1 Mar 2021 17:36:53 +1100, Alexey Kardashevskiy wrote:
> The IOMMU table is divided into pools for concurrent mappings and each
> pool has a separate spinlock. When taking the ownership of an IOMMU group
> to pass through a device to a VM, we lock these spinlocks which triggers
> a false negative warning in lockdep (below).
>
> This fixes it by annotating the large pool's spinlock as a nest lock
> which makes lockdep not complaining when locking nested locks if
> the nest lock is locked already.
>
> [...]
Applied to powerpc/next.
[1/1] powerpc/iommu: Annotate nested lock for lockdep
https://git.kernel.org/powerpc/c/cc7130bf119add37f36238343a593b71ef6ecc1e
cheers
