Messages in this thread | | | Date | Thu, 18 Feb 2016 11:06:16 +0000 | From | Marc Zyngier <> | Subject | Re: [RFC v3 07/15] iommu: iommu_get/put_single_reserved |
| |
On Fri, 12 Feb 2016 08:13:09 +0000 Eric Auger <eric.auger@linaro.org> wrote:
> This patch introduces iommu_get/put_single_reserved. > > iommu_get_single_reserved allows to allocate a new reserved iova page > and map it onto the physical page that contains a given physical address. > It returns the iova that is mapped onto the provided physical address. > Hence the physical address passed in argument does not need to be aligned. > > In case a mapping already exists between both pages, the IOVA mapped > to the PA is directly returned. > > Each time an iova is successfully returned a binding ref count is > incremented. > > iommu_put_single_reserved decrements the ref count and when this latter > is null, the mapping is destroyed and the iova is released.
I wonder if there is a requirement for the caller to find out about the size of the mapping, or to impose a given size... MSIs clearly do not have that requirement (this is always a 32bit value), but since allocations usually pair address and size, I though I'd ask...
Thanks,
M. -- Jazz is not dead. It just smells funny.
| |