[RFC net-next v2 2/9] netdev-genl: Export NAPI index

[Joe Damato <jdamato@fastly.com>]

Export the NAPI index on napi-get operations. This index will be used in
future commits to set per-NAPI parameters.

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 Documentation/netlink/specs/netdev.yaml | 9 +++++++++
 include/uapi/linux/netdev.h             | 1 +
 net/core/netdev-genl.c                  | 3 +++
 3 files changed, 13 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 959755be4d7f..cf3e77c6fd5e 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -244,6 +244,14 @@ attribute-sets:
              threaded mode. If NAPI is not in threaded mode (i.e. uses normal
              softirq context), the attribute will be absent.
         type: u32
+      -
+        name: index
+        doc: The index of the NAPI instance. Refers to persistent storage for
+             any NAPI with the same index.
+        type: u32
+        checks:
+          min: 0
+          max: s32-max
   -
     name: queue
     attributes:
@@ -593,6 +601,7 @@ operations:
             - ifindex
             - irq
             - pid
+            - index
       dump:
         request:
           attributes:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 43742ac5b00d..e06e33acb6fd 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -121,6 +121,7 @@ enum {
 	NETDEV_A_NAPI_ID,
 	NETDEV_A_NAPI_IRQ,
 	NETDEV_A_NAPI_PID,
+	NETDEV_A_NAPI_INDEX,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index a17d7eaeb001..9561841b9d2d 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -182,6 +182,9 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 	if (napi->irq >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_IRQ, napi->irq))
 		goto nla_put_failure;
 
+	if (napi->index >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_INDEX, napi->index))
+		goto nla_put_failure;
+
 	if (napi->thread) {
 		pid = task_pid_nr(napi->thread);
 		if (nla_put_u32(rsp, NETDEV_A_NAPI_PID, pid))
-- 
2.25.1