Messages in this thread | | | Subject | Re: [RFC v3 05/10] iommu: Do not map reserved regions | From | Robin Murphy <> | Date | Tue, 6 Dec 2016 17:36:34 +0000 |
| |
On 15/11/16 13:09, Eric Auger wrote: > As we introduced IOMMU_RESV_NOMAP and IOMMU_RESV_MSI regions, > let's prevent those new regions from being mapped. > > Signed-off-by: Eric Auger <eric.auger@redhat.com> > --- > drivers/iommu/iommu.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 6ee529f..a4530ad 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -343,6 +343,9 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group, > start = ALIGN(entry->start, pg_size); > end = ALIGN(entry->start + entry->length, pg_size); > > + if (entry->prot & IOMMU_RESV_MASK)
This seems to be the only place that this mask is used, and frankly I think it's less clear than simply "(IOMMU_RESV_NOMAP | IOMMU_RESV_MSI)" would be, at which point we may as well drop the mask and special value trickery altogether. Plus, per my previous comment, if it were to be "if (entry->type != <direct mapped type>)" instead, that's about as obvious as it can get.
Robin.
> + continue; > + > for (addr = start; addr < end; addr += pg_size) { > phys_addr_t phys_addr; > >
| |