[PATCH v2 1/9] iommupt: Remove the sanity check for pt_num_items_lg2() at the top level

[Jason Gunthorpe <jgg@nvidia.com>]

This was ill conceived, the existing formats work OK because they
happen to support pt_num_items_lg2() at the top level. However the
documentation is clear that is not permitted because ARMv8 has
concatenated top levels and we do not want to calculate an exact
pt_num_items_lg2() for the top level special case.

The logic to compute the number of items of the top level is shown in
pt_top_memsize_lg2() which is:

	num_items_lg2 = common->max_vasz_lg2 - pt_table_item_lg2sz(&pts);

Which is pointless to try and sanity check.

Reviewed-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/generic_pt/iommu_pt.h | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/drivers/iommu/generic_pt/iommu_pt.h b/drivers/iommu/generic_pt/iommu_pt.h
index c2752151c80af1..f1320c7e88dbbb 100644
--- a/drivers/iommu/generic_pt/iommu_pt.h
+++ b/drivers/iommu/generic_pt/iommu_pt.h
@@ -1207,20 +1207,6 @@ static int pt_init_common(struct pt_common *common)
 		     PT_FORCE_ENABLED_FEATURES))
 		return -EOPNOTSUPP;
 
-	/*
-	 * Check if the top level of the page table is too small to hold the
-	 * specified maxvasz.
-	 */
-	if (!pt_feature(common, PT_FEAT_DYNAMIC_TOP) &&
-	    top_range.top_level != PT_MAX_TOP_LEVEL) {
-		struct pt_state pts = { .range = &top_range,
-					.level = top_range.top_level };
-
-		if (common->max_vasz_lg2 >
-		    pt_num_items_lg2(&pts) + pt_table_item_lg2sz(&pts))
-			return -EOPNOTSUPP;
-	}
-
 	if (common->max_oasz_lg2 == 0)
 		common->max_oasz_lg2 = pt_max_oa_lg2(common);
 	else
-- 
2.43.0