[RFC/PATCH 2/7] iommu-api: Add map_range/unmap_range functions
Thierry Reding
thierry.reding at gmail.com
Mon Jun 30 12:42:10 PDT 2014
On Mon, Jun 30, 2014 at 09:51:51AM -0700, Olav Haugan wrote:
[...]
> +int iommu_map_range(struct iommu_domain *domain, unsigned int iova,
> + struct scatterlist *sg, unsigned int len, int prot)
> +{
> + if (unlikely(domain->ops->map_range == NULL))
> + return -ENODEV;
Should we perhaps make this mandatory? For drivers that don't provide it
we could implement a generic helper that wraps iommu_{map,unmap}().
> +
> + BUG_ON(iova & (~PAGE_MASK));
> +
> + return domain->ops->map_range(domain, iova, sg, len, prot);
> +}
> +EXPORT_SYMBOL_GPL(iommu_map_range);
> +
> +int iommu_unmap_range(struct iommu_domain *domain, unsigned int iova,
> + unsigned int len)
> +{
> + if (unlikely(domain->ops->unmap_range == NULL))
> + return -ENODEV;
> +
> + BUG_ON(iova & (~PAGE_MASK));
> +
> + return domain->ops->unmap_range(domain, iova, len);
> +}
> +EXPORT_SYMBOL_GPL(iommu_unmap_range);
Could these be renamed iommu_{map,unmap}_sg() instead to make it more
obvious what exactly they map? And perhaps this could take an sg_table
instead, which already provides a count and is a very common structure
used in drivers (and the DMA mapping API).
Thierry
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