From 67f3e53d2a37ab27b00610eb25724103055beafc Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Fri, 25 Oct 2019 19:08:32 +0100 Subject: [PATCH] iommu/io-pgtable-arm: Simplify bounds checks We're merely checking that the relevant upper bits of each address are all zero, so there are cheaper ways to achieve that. Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- drivers/iommu/io-pgtable-arm.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index abe79457..5da3cbd 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -491,8 +491,7 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova, 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))) + if (WARN_ON(iova >> data->iop.cfg.ias || paddr >> data->iop.cfg.oas)) return -ERANGE; prot = arm_lpae_prot_to_pte(data, iommu_prot); @@ -663,7 +662,7 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova, if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size)) return 0; - if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias))) + if (WARN_ON(iova >> data->iop.cfg.ias)) return 0; return __arm_lpae_unmap(data, gather, iova, size, lvl, ptep); -- 2.7.4