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.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> Reviewed-by: David Gibson <da...@gibson.dropbear.id.au> --- arch/powerpc/platforms/powernv/pci.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c index 4945e87..9ec7d68 100644 --- a/arch/powerpc/platforms/powernv/pci.c +++ b/arch/powerpc/platforms/powernv/pci.c @@ -589,19 +589,27 @@ struct pci_ops pnv_pci_ops = { .write = pnv_pci_write_config, }; +static unsigned long pnv_dmadir_to_flags(enum dma_data_direction direction) +{ + switch (direction) { + case DMA_BIDIRECTIONAL: + case DMA_FROM_DEVICE: + return TCE_PCI_READ | TCE_PCI_WRITE; + case DMA_TO_DEVICE: + return TCE_PCI_READ; + default: + return 0; + } +} + 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 = pnv_dmadir_to_flags(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; -- 2.0.0 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev