[RFC net-next v4 2/9] netdev-genl: Dump napi_defer_hard_irqs

[Joe Damato <jdamato@fastly.com>]

Support dumping defer_hard_irqs for a NAPI ID.

Signed-off-by: Joe Damato <jdamato@fastly.com>
---
 Documentation/netlink/specs/netdev.yaml | 8 ++++++++
 include/uapi/linux/netdev.h             | 1 +
 net/core/netdev-genl.c                  | 6 ++++++
 tools/include/uapi/linux/netdev.h       | 1 +
 4 files changed, 16 insertions(+)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 08412c279297..585e87ec3c16 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -248,6 +248,13 @@ 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: defer-hard-irqs
+        doc: The number of consecutive empty polls before IRQ deferral ends
+             and hardware IRQs are re-enabled.
+        type: u32
+        checks:
+          max: s32-max
   -
     name: queue
     attributes:
@@ -636,6 +643,7 @@ operations:
             - ifindex
             - irq
             - pid
+            - defer-hard-irqs
       dump:
         request:
           attributes:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 7c308f04e7a0..13dc0b027e86 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -122,6 +122,7 @@ enum {
 	NETDEV_A_NAPI_ID,
 	NETDEV_A_NAPI_IRQ,
 	NETDEV_A_NAPI_PID,
+	NETDEV_A_NAPI_DEFER_HARD_IRQS,
 
 	__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 1cb954f2d39e..de9bd76f43f8 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -161,6 +161,7 @@ static int
 netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 			const struct genl_info *info)
 {
+	u32 napi_defer_hard_irqs;
 	void *hdr;
 	pid_t pid;
 
@@ -189,6 +190,11 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 			goto nla_put_failure;
 	}
 
+	napi_defer_hard_irqs = napi_get_defer_hard_irqs(napi);
+	if (nla_put_s32(rsp, NETDEV_A_NAPI_DEFER_HARD_IRQS,
+			napi_defer_hard_irqs))
+		goto nla_put_failure;
+
 	genlmsg_end(rsp, hdr);
 
 	return 0;
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 7c308f04e7a0..13dc0b027e86 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -122,6 +122,7 @@ enum {
 	NETDEV_A_NAPI_ID,
 	NETDEV_A_NAPI_IRQ,
 	NETDEV_A_NAPI_PID,
+	NETDEV_A_NAPI_DEFER_HARD_IRQS,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
-- 
2.25.1