@@ -203,6 +203,7 @@ extern int iommu_take_ownership(struct iommu_table *tbl);
extern void iommu_release_ownership(struct iommu_table *tbl);
extern enum dma_data_direction iommu_tce_direction(unsigned long tce);
+extern unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir);
#endif /* __KERNEL__ */
#endif /* _ASM_IOMMU_H */
@@ -916,6 +916,21 @@ enum dma_data_direction iommu_tce_direction(unsigned long tce)
}
EXPORT_SYMBOL_GPL(iommu_tce_direction);
+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);
+
void iommu_flush_tce(struct iommu_table *tbl)
{
/* Flush/invalidate TLB caches if necessary */
@@ -593,15 +593,10 @@ static int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
unsigned long uaddr, enum dma_data_direction direction,
struct dma_attrs *attrs, bool rm)
{
- u64 proto_tce;
+ u64 proto_tce = iommu_direction_to_tce_perm(direction);
__be64 *tcep, *tces;
u64 rpn;
- proto_tce = TCE_PCI_READ; // Read allowed
-
- if (direction != DMA_TO_DEVICE)
- proto_tce |= TCE_PCI_WRITE;
-
tces = tcep = ((__be64 *)tbl->it_base) + index - tbl->it_offset;
rpn = __pa(uaddr) >> tbl->it_page_shift;
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. 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> --- arch/powerpc/include/asm/iommu.h | 1 + arch/powerpc/kernel/iommu.c | 15 +++++++++++++++ arch/powerpc/platforms/powernv/pci.c | 7 +------ 3 files changed, 17 insertions(+), 6 deletions(-)