On Wed, Jan 10, 2018 at 12:22:18PM +0000, Robin Murphy wrote: >> + if (phys_addr == SWIOTLB_MAP_ERROR) >> + goto out_warn; >> - /* Confirm address can be DMA'd by device */ >> - if (dev_addr + size - 1 > dma_mask) { >> - printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", >> - (unsigned long long)dma_mask, >> - (unsigned long long)dev_addr); >> + *dma_handle = swiotlb_phys_to_dma(dev, phys_addr); > > nit: this should probably go after the dma_coherent_ok() check (as with the > original logic). But the originall logic also needs the dma_addr_t for the dma_coherent_ok check: dev_addr = swiotlb_phys_to_dma(hwdev, paddr); /* Confirm address can be DMA'd by device */ if (dev_addr + size - 1 > dma_mask) { ... goto err_warn; } or do you mean assining to *dma_handle? The dma_handle is not valid for a failure return, so I don't think this should matter. >> + if (ret) { >> + *dma_handle = swiotlb_virt_to_bus(hwdev, ret); >> + if (dma_coherent_ok(hwdev, *dma_handle, size)) { >> + memset(ret, 0, size); >> + return ret; >> + } > > Aren't we leaking the pages here? Yes, that free_pages got lost somewhere in the rebases, I've added it back.