Merge branch 'remotes/lorenzo/pci/controller-misc'

[linux] / drivers / pci / Kconfig

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 4a28e07..2dcc304 100644 (file)
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -135,6 +135,23 @@ config PCI_PASID
 
          If unsure, say N.
 
+config PCI_P2PDMA
+       bool "PCI peer-to-peer transfer support"
+       depends on PCI && ZONE_DEVICE
+       select GENERIC_ALLOCATOR
+       help
+         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 transations must be between devices behind the same root
+         port.
+
+         If unsure, say N.
+
 config PCI_LABEL
        def_bool y if (DMI || ACPI)
        depends on PCI