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| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2015-06-05 06:35:05 (GMT) |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-06-11 05:14:56 (GMT) |
| commit | 10b35b2b7485c342334a48cf199063eed8b8748e (patch) | |
| tree | c609824799ab76a33d1dad1c6a9a254cb8baad99 /arch/powerpc/kernel | |
| parent | 22af48596e9c92313d475306b684f844301ea4cd (diff) | |
| download | linux-10b35b2b7485c342334a48cf199063eed8b8748e.tar.xz | |
powerpc/powernv: Do not set "read" flag if direction==DMA_NONE
Normally a bitmap from the iommu_table is used to track what TCE entry
is in use. Since we are going to use iommu_table without its locks and
do xchg() instead, it becomes essential not to put bits which are not
implied in the direction flag as the old TCE value (more precisely -
the permission bits) will be used to decide whether to put the page or not.
This adds iommu_direction_to_tce_perm() (its counterpart is there already)
and uses it for powernv's pnv_tce_build().
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/iommu.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 0019c80..ac2f959 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -866,6 +866,21 @@ void iommu_free_coherent(struct iommu_table *tbl, size_t size, } } +unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir) +{ + switch (dir) { + case DMA_BIDIRECTIONAL: + return TCE_PCI_READ | TCE_PCI_WRITE; + case DMA_FROM_DEVICE: + return TCE_PCI_WRITE; + case DMA_TO_DEVICE: + return TCE_PCI_READ; + default: + return 0; + } +} +EXPORT_SYMBOL_GPL(iommu_direction_to_tce_perm); + #ifdef CONFIG_IOMMU_API /* * SPAPR TCE API |