On Mon, Oct 06, 2014 at 12:02:47PM -0700, Olav Haugan wrote:
> On 9/25/2014 10:01 AM, Joerg Roedel wrote:
> >On Mon, Aug 11, 2014 at 03:45:50PM -0700, Olav Haugan wrote:
> >>+static inline int iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
> >>+ struct scatterlist *sg, unsigned int nents,
> >>+ int prot, unsigned long flags)
> >>+{
> >>+ return domain->ops->map_sg(domain, iova, sg, nents, prot, flags);
> >>+}
> >>+
> >>+static inline int iommu_unmap_sg(struct iommu_domain *domain,
> >>+ unsigned long iova, size_t size,
> >>+ unsigned long flags)
> >>+{
> >>+ return domain->ops->unmap_sg(domain, iova, size, flags);
> >>+}
> >
> >I have thought a little bit more about this interface and think that it
> >would be better to just return a size_t from iommu_map_sg(). The
> >function returns the amount of address space mapped by it, 0 in the
> >worst case.
> >
> >This makes it easy to unmap the region just with
> >iommu_unmap(domain, iova, size) in the end and removing the need for a
> >new iommu_unmap_sg() function. Also the error-path of the map_sg
> >call-backs becomes easier as the function then just returns the amount
> >of address-space already mapped before the error happened.
> >
> >So the prototype would be:
> >
> > size_t iommu_map_sg(struct iommu_domain *domain,
> > unsigned long iova,
> > struct scatterlist *sg,
> > unsigned int nents,
> > int prot);
> >
> >(as I said before, the flags parameter should not be added by this
> > patch-set).
> >
>
> Ok, sounds good. I'll post v6 soon.
Perhaps make the return value ssize_t so that we can propagate errors?
Thierry
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