diff options
Diffstat (limited to 'drivers/iommu/io-pgtable-arm.c')
-rw-r--r-- | drivers/iommu/io-pgtable-arm.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 52700fa..b182039 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -331,8 +331,12 @@ static arm_lpae_iopte arm_lpae_install_table(arm_lpae_iopte *table, if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS) new |= ARM_LPAE_PTE_NSTABLE; - /* Ensure the table itself is visible before its PTE can be */ - wmb(); + /* + * Ensure the table itself is visible before its PTE can be. + * Whilst we could get away with cmpxchg64_release below, this + * doesn't have any ordering semantics when !CONFIG_SMP. + */ + dma_wmb(); old = cmpxchg64_relaxed(ptep, curr, new); |