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: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Robin Murphy 2019-10-25 19:08:31 +01:00 committed by Will Deacon
parent b5813c164e
commit f7b90d2c74

View File

@ -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;