docs: networking: document NAPI

Add basic documentation about NAPI. We can stop linking to the ancient
doc on the LF wiki.

Link: https://lore.kernel.org/all/20230315223044.471002-1-kuba@kernel.org/
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> # for ctucanfd-driver.rst
Reviewed-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230322053848.198452-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 674ee5daa7b1ca..18a5be6ddd0f7c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -509,15 +509,18 @@ static inline bool napi_reschedule(struct napi_struct *napi)
 	return false;
 }
 
-bool napi_complete_done(struct napi_struct *n, int work_done);
 /**
- *	napi_complete - NAPI processing complete
- *	@n: NAPI context
+ * napi_complete_done - NAPI processing complete
+ * @n: NAPI context
+ * @work_done: number of packets processed
  *
- * Mark NAPI processing as complete.
- * Consider using napi_complete_done() instead.
+ * Mark NAPI processing as complete. Should only be called if poll budget
+ * has not been completely consumed.
+ * Prefer over napi_complete().
  * Return false if device should avoid rearming interrupts.
  */
+bool napi_complete_done(struct napi_struct *n, int work_done);
+
 static inline bool napi_complete(struct napi_struct *n)
 {
 	return napi_complete_done(n, 0);