Commits
Christian König committed 0f97da83102
PCI/P2PDMA: Allow P2P DMA between any devices under AMD ZEN Root Complex The PCI specs say that peer-to-peer DMA should be supported between any two devices that have a common upstream PCI-to-PCI bridge. But devices under different Root Ports don't share a common upstream bridge, and PCIe r4.0, sec 1.3.1, says routing peer-to-peer transactions between Root Ports in the same Root Complex is optional. Many Root Complexes, including AMD ZEN, *do* support peer-to-peer DMA even between Root Ports. Add a whitelist and allow peer-to-peer DMA if both participants are attached to a Root Complex known to support it. Link: https://lore.kernel.org/linux-pci/20190418115859.2394-1-christian.koenig@amd.com Signed-off-by: Christian König <christian.koenig@amd.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>