PCI peer-to-peer transfer support

modulename: p2pdma.ko

configname: CONFIG_PCI_P2PDMA

Linux Kernel Configuration
└─>Device Drivers
└─>PCI support
└─>PCI peer-to-peer transfer support
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Enableѕ drivers to do PCI peer-to-peer transactions to and from
BARs that are exposed in other devices that are the part of
the hierarchy where peer-to-peer DMA is guaranteed by the PCI
specification to work (ie. anything below a single PCI bridge).

Many PCIe root complexes do not support P2P transactions and
it's hard to tell which support it at all, so at this time,
P2P DMA transactions must be between devices behind the same root
port.

If unsure, say N.

source code: