diff options
| author | Robin Murphy <Robin.Murphy@arm.com> | 2015-09-17 17:42:16 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2015-09-22 17:35:33 +0100 |
| commit | ffcb6d1686ceb4a6b50776fb2597ab0e4dd79040 (patch) | |
| tree | 55f734b2d6a0ee79b0c0e5ede21e7a94feadd0c4 /drivers/iommu/Kconfig | |
| parent | 6ff33f3902c3b1c5d0db6b1e2c70b6d76fba357f (diff) | |
| download | linux-ffcb6d1686ceb4a6b50776fb2597ab0e4dd79040.tar.bz2 | |
iommu/io-pgtable-arm: Don't use dma_to_phys()
In checking whether DMA addresses differ from physical addresses, using
dma_to_phys() is actually the wrong thing to do, since it may hide any
DMA offset, which is precisely one of the things we are checking for.
Simply casting between the two address types, whilst ugly, is in fact
the appropriate course of action. Further care (and ugliness) is also
necessary in the comparison to avoid truncation if phys_addr_t and
dma_addr_t differ in size.
We can also reject any device with a fixed DMA offset up-front at page
table creation, leaving the allocation-time check for the more subtle
cases like bounce buffering due to an incorrect DMA mask.
Furthermore, we can then fix the hackish KConfig dependency so that
architectures without a dma_to_phys() implementation may still
COMPILE_TEST (or even use!) the code. The true dependency is on the
DMA API, so use the appropriate symbol for that.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: folded in selftest fix from Yong Wu]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/iommu/Kconfig')
| -rw-r--r-- | drivers/iommu/Kconfig | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 4664c2a96c67..3dc1bcb0d01d 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -23,8 +23,7 @@ config IOMMU_IO_PGTABLE config IOMMU_IO_PGTABLE_LPAE bool "ARMv7/v8 Long Descriptor Format" select IOMMU_IO_PGTABLE - # SWIOTLB guarantees a dma_to_phys() implementation - depends on ARM || ARM64 || (COMPILE_TEST && SWIOTLB) + depends on HAS_DMA && (ARM || ARM64 || COMPILE_TEST) help Enable support for the ARM long descriptor pagetable format. This allocator supports 4K/2M/1G, 16K/32M and 64K/512M page |