diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2015-07-16 20:40:12 +0200 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2015-07-28 16:47:56 +0200 |
| commit | 8f6429c7cb59f28433253575cc8e3262eed63592 (patch) | |
| tree | b0ba92c894735701a01d289f92c42c221c6d3cf1 /drivers/iommu/intel-iommu.c | |
| parent | Linux 4.2-rc3 (diff) | |
| download | linux-8f6429c7cb59f28433253575cc8e3262eed63592.tar.xz linux-8f6429c7cb59f28433253575cc8e3262eed63592.zip | |
iommu/iova: Avoid over-allocating when size-aligned
Currently, allocating a size-aligned IOVA region quietly adjusts the
actual allocation size in the process, returning a rounded-up
power-of-two-sized allocation. This results in mismatched behaviour in
the IOMMU driver if the original size was not a power of two, where the
original size is mapped, but the rounded-up IOVA size is unmapped.
Whilst some IOMMUs will happily unmap already-unmapped pages, others
consider this an error, so fix it by computing the necessary alignment
padding without altering the actual allocation size. Also clean up by
making pad_size unsigned, since its callers always pass unsigned values
and negative padding makes little sense here anyway.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index a98a7b27aca1..92101597cede 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3233,6 +3233,8 @@ static struct iova *intel_alloc_iova(struct device *dev, /* Restrict dma_mask to the width that the iommu can handle */ dma_mask = min_t(uint64_t, DOMAIN_MAX_ADDR(domain->gaw), dma_mask); + /* Ensure we reserve the whole size-aligned region */ + nrpages = __roundup_pow_of_two(nrpages); if (!dmar_forcedac && dma_mask > DMA_BIT_MASK(32)) { /* |