CONFIG_PCI_P2PDMA is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT
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)
Enables 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.
Enabling this option will reduce the entropy of x86 KASLR memory
regions. For example - on a 46 bit system, the entropy goes down
from 16 bits to 15 bits. The actual reduction in entropy depends
on the physical address bits, on processor features, kernel config
(5 level page table) and physical memory present on the system.
If unsure, say N.
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.
Enabling this option will reduce the entropy of x86 KASLR memory
regions. For example - on a 46 bit system, the entropy goes down
from 16 bits to 15 bits. The actual reduction in entropy depends
on the physical address bits, on processor features, kernel config
(5 level page table) and physical memory present on the system.
If unsure, say N.