Commits
Chris Metcalf committed 41bb38fc539
tile pci: enable IOMMU to support DMA for legacy devices This change uses the TRIO IOMMU to map the PCI DMA space and physical memory at different addresses. We also now use the dma_mapping_ops to provide support for non-PCI DMA, PCIe DMA (64-bit) and legacy PCI DMA (32-bit). We use the kernel's software I/O TLB framework (i.e. bounce buffers) for the legacy 32-bit PCI device support since there are a limited number of TLB entries in the IOMMU and it is non-trivial to handle indexing, searching, matching, etc. For 32-bit devices the performance impact of bounce buffers should not be a concern. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>