Commit f7b90d2c authored by Robin Murphy's avatar Robin Murphy Committed by Will Deacon
Browse files

iommu/io-pgtable-arm: Rationalise size check 



It makes little sense to only validate the requested size after we think
we've found a matching block size - making the check up-front is simple,
and far more logical than waiting to walk off the bottom of the table to
infer that we must have been passed a bogus size to start with.

We're missing an equivalent check on the unmap path, so add that as well
for consistency.

Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent b5813c16

drivers/iommu/io-pgtable-arm.c

+9 −1
Original line number Diff line number Diff line
@@ -392,7 +392,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova, 
	ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);



	/* If we can install a leaf entry at this level, then do so */

	if (size == block_size && (size & cfg->pgsize_bitmap))

	if (size == block_size)

		return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);



	/* We can't allocate tables at the final level */
@@ -479,6 +479,7 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova, 
			phys_addr_t paddr, size_t size, int iommu_prot)

{

	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);

	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	arm_lpae_iopte *ptep = data->pgd;

	int ret, lvl = ARM_LPAE_START_LVL(data);

	arm_lpae_iopte prot;
@@ -487,6 +488,9 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova, 
	if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))

		return 0;



	if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))

		return -EINVAL;



	if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias) ||

		    paddr >= (1ULL << data->iop.cfg.oas)))

		return -ERANGE;
@@ -652,9 +656,13 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova, 
			     size_t size, struct iommu_iotlb_gather *gather)

{

	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);

	struct io_pgtable_cfg *cfg = &data->iop.cfg;

	arm_lpae_iopte *ptep = data->pgd;

	int lvl = ARM_LPAE_START_LVL(data);



	if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))

		return 0;



	if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))

		return 0;

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