Messages in this thread | | | Date | Tue, 11 Oct 2011 12:19:36 +0200 | From | "Roedel, Joerg" <> | Subject | Re: [PATCH v3 1/6] iommu/core: split mapping to page sizes as supported by the hardware |
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Hi Ohad,
On Mon, Oct 10, 2011 at 01:02:46PM -0400, Ohad Ben-Cohen wrote: > On Mon, Oct 10, 2011 at 5:36 PM, Roedel, Joerg <Joerg.Roedel@amd.com> wrote: > > Yes, somthing like that. Probably the iommu_ops->unmap function should > > be turned into a unmap_page function call which only takes an iova and > > no size parameter. The iommu-driver unmaps the page pointing to that > > iova and returns the size of the page unmapped. This still allows the > > simple implementation for the unmap-call. > > Yes, exactly. It will take some time to migrate all drivers (today we > have 4 drivers, each of which is implementing a slightly different > ->unmap() semantics), but at least let's not accept any new driver > that doesn't adhere to this, otherwise it's going to be even harder > for the API to evolve.
Agreed. We should change the existing drivers one-by-one.
> > We don't need to really enforce the calls to be symetric. But we can > > define that we only give the guarantee about what will be unmapped > > when the calls are symetric. > > Sounds good to me. I'll add this to the kernel doc patch (which I'll > submit after this patch set materializes), and when/if we move to > symmetric only, we will update it.
Great. So if no one disagrees with this direction (this means all the other people on Cc :) ) it is the way to.
Joerg
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