Add Documentation to help users use PCI endpoint to create virtual
functions using configfs. An endpoint function is designated as a
virtual endpoint function device when it is linked to a physical
endpoint function device (instead of a endpoint controller).
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
Documentation/PCI/endpoint/pci-endpoint-cfs.rst | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/Documentation/PCI/endpoint/pci-endpoint-cfs.rst b/Documentation/PCI/endpoint/pci-endpoint-cfs.rst
index 696f8eeb4738..56fb33c5e8fd 100644
--- a/Documentation/PCI/endpoint/pci-endpoint-cfs.rst
+++ b/Documentation/PCI/endpoint/pci-endpoint-cfs.rst
@@ -43,6 +43,7 @@ entries corresponding to EPF driver will be created by the EPF core.
.. <EPF Driver1>/
... <EPF Device 11>/
... <EPF Device 21>/
+ ... <EPF Device 31>/
.. <EPF Driver2>/
... <EPF Device 12>/
... <EPF Device 22>/
@@ -68,6 +69,7 @@ created)
... subsys_vendor_id
... subsys_id
... interrupt_pin
+ ... <Symlink EPF Device 31>/
... primary/
... <Symlink EPC Device1>/
... secondary/
@@ -79,6 +81,13 @@ interface should be added in 'primary' directory and symlink of endpoint
controller connected to secondary interface should be added in 'secondary'
directory.
+The <EPF Device> directory can have a list of symbolic links
+(<Symlink EPF Device 31>) to other <EPF Device>. These symbolic links should
+be created by the user to represent the virtual functions that are bound to
+the physical function. In the above directory structure <EPF Device 11> is a
+physical function and <EPF Device 31> is a virtual function. An EPF device once
+it's linked to another EPF device, cannot be linked to a EPC device.
+
EPC Device
==========
@@ -98,7 +107,8 @@ entries corresponding to EPC device will be created by the EPC core.
The <EPC Device> directory will have a list of symbolic links to
<EPF Device>. These symbolic links should be created by the user to
-represent the functions present in the endpoint device.
+represent the functions present in the endpoint device. Only <EPF Device>
+that represents a physical function can be linked to a EPC device.
The <EPC Device> directory will also have a *start* field. Once
"1" is written to this field, the endpoint device will be ready to
--
2.17.1
