iommu: Defer the early return in arm_(v7s/lpae)_map
Although handling a mapping request with no permissions is a
trivial no-op, defer the early return until after the size/range
checks so that we are consistent with other mapping requests.
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Link: https://lore.kernel.org/r/20201207115758.9400-1-zhukeqian1@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index a7a9bc0..8ade72a 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -444,10 +444,6 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
arm_lpae_iopte prot;
long iaext = (s64)iova >> cfg->ias;
- /* If no access, then nothing to do */
- if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
- return 0;
-
if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
return -EINVAL;
@@ -456,6 +452,10 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
if (WARN_ON(iaext || paddr >> cfg->oas))
return -ERANGE;
+ /* If no access, then nothing to do */
+ if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
+ return 0;
+
prot = arm_lpae_prot_to_pte(data, iommu_prot);
ret = __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep, gfp);
/*
