Re: [PATCH v3 net-next 4/4] ulp: Documention for ULP infrastructure

Add a doc in Documentation/networking

Signed-off-by: Tom Herbert <redacted>
---
Documentation/networking/ulp.txt | 82 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 82 insertions(+)
create mode 100644 Documentation/networking/ulp.txt

diff --git a/Documentation/networking/ulp.txt b/Documentation/networking/ulp.txt
new file mode 100644
index 000000000000..4d830314b0ff
--- /dev/null
+++ b/Documentation/networking/ulp.txt

@@ -0,0 +1,82 @@
+Upper Layer Protocol (ULP) Infrastructure
+=========================================
+
+The ULP kernel infrastructure provides a means to hook upper layer
+protocol support on a socket. A module may register a ULP hook
+in the kernel. ULP processing is enabled by a setsockopt on a socket
+that specifies the name of the registered ULP to invoked. An
+initialization function is defined for each ULP that can change the
+function entry points of the socket (sendmsg, rcvmsg, etc.) or change
+the socket in other fundamental ways.
+
+Note, no synchronization is enforced between the setsockopt to enable
+a ULP and ongoing asynchronous operations on the socket (such as a
+blocked read). If synchronization is required this must be handled by
+the ULP and caller.
+
+User interface
+==============
+
+The structure for the socket SOL_ULP options is defined in socket.h.
+
+Example to enable "my_ulp" ULP on a socket:
+
+struct ulp_config ulpc = {
+    .ulp_name = "my_ulp",
+};
+
+setsockopt(sock, SOL_SOCKET, SO_ULP, &ulpc, sizeof(ulpc))
+
+The ulp_config includes a "__u8 ulp_params[0]" filled that may be used