Messages in this thread | | | Date | Thu, 25 Apr 2019 11:19:12 -0700 | From | Jacob Pan <> | Subject | Re: [PATCH v2 06/19] drivers core: Add I/O ASID allocator |
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Hi Christoph,
On Tue, 23 Apr 2019 23:19:03 -0700 Christoph Hellwig <hch@infradead.org> wrote:
> On Tue, Apr 23, 2019 at 04:31:06PM -0700, Jacob Pan wrote: > > The allocator doesn't really belong in drivers/iommu because some > > drivers would like to allocate PASIDs for devices that aren't > > managed by an IOMMU, using the same ID space as IOMMU. It doesn't > > really belong in drivers/pci either since platform device also > > support PASID. Add the allocator in drivers/base. > > I'd still add it to drivers/iommu, just selectable separately from the > core iommu code.. Perhaps I misunderstood. If a driver wants to use IOASIDs w/o iommu subsystem even turned on, how could selecting from the core iommu code help? Could you elaborate on "selectable"?
From VT-d's perspective, PASIDs are only used with IOMMU on. Jean knows other use cases.
Jacob
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