Re: [PATCH 1/7] genirq/msi: Add a new field in msi_desc to store an IOMMU cookie
From: Thomas Gleixner
Date: Thu Apr 18 2019 - 15:28:24 EST
On Thu, 18 Apr 2019, Julien Grall wrote:
> When an MSI doorbell is located downstream of an IOMMU, it is required
> to swizzle the physical address with an appropriately-mapped IOVA for any
> device attached to one of our DMA ops domain.
>
> At the moment, the allocation of the mapping may be done when composing
> the message. However, the composing may be done in non-preemtible
> context while the allocation requires to be called from preemptible
> context.
>
> A follow-up patch will split the current logic in two functions
> requiring to keep an IOMMU cookie per MSI.
>
> This patch introduces a new field in msi_desc to store an IOMMU cookie
> when CONFIG_IOMMU_DMA is selected.
# git grep 'This patch' Documentation/process/
Applied to the whole series.
Thanks
tglx