iommu: Implement DOMAIN_ATTR_PAGING attribute

This attribute of a domain can be queried to find out if the
domain supports setting up page-tables using the iommu_map()
and iommu_unmap() functions.

Signed-off-by: Joerg Roedel <joro@8bytes.org>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 4e6d6f8..0e0e5f2 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -869,6 +869,7 @@ int iommu_domain_get_attr(struct iommu_domain *domain,
                          enum iommu_attr attr, void *data)
 {
        struct iommu_domain_geometry *geometry;
+       bool *paging;
        int ret = 0;
 
        switch (attr) {
@@ -877,6 +878,10 @@ int iommu_domain_get_attr(struct iommu_domain *domain,
                *geometry = domain->geometry;
 
                break;
+       case DOMAIN_ATTR_PAGING:
+               paging  = data;
+               *paging = (domain->ops->pgsize_bitmap != 0UL);
+               break;
        default:
                if (!domain->ops->domain_get_attr)
                        return -EINVAL;

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 7e6ce72..26066f5 100644 (file)
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -59,6 +59,7 @@ struct iommu_domain {
 
 enum iommu_attr {
        DOMAIN_ATTR_GEOMETRY,
+       DOMAIN_ATTR_PAGING,
        DOMAIN_ATTR_MAX,
 };