[ethtool-next PATCH] rings: add support to set/get cqe size

[Subbaraya Sundeep <sbhatta@marvell.com>]

After a packet is sent or received by NIC then NIC posts
a completion queue event which consists of transmission status
(like send success or error) and received status(like
pointers to packet fragments). These completion events may
also use a ring similar to rx and tx rings. This patch
introduces cqe-size ethtool parameter to modify the size
of the completion queue event if NIC hardware has that capability.
With this patch in place, cqe size can be set via
"ethtool -G <dev> cqe-size xxx" and get via "ethtool -g <dev>".

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
---
 ethtool.8.in    | 4 ++++
 ethtool.c       | 1 +
 netlink/rings.c | 7 +++++++
 3 files changed, 12 insertions(+)

diff --git a/ethtool.8.in b/ethtool.8.in
index cbfe9cf..92ba229 100644
--- a/ethtool.8.in
+++ b/ethtool.8.in
@@ -200,6 +200,7 @@ ethtool \- query or control network driver and hardware settings
 .BN tx
 .BN rx\-buf\-len
 .BN tx\-push
+.BN cqe\-size
 .HP
 .B ethtool \-i|\-\-driver
 .I devname
@@ -577,6 +578,9 @@ Changes the size of a buffer in the Rx ring.
 .TP
 .BI tx\-push \ on|off
 Specifies whether TX push should be enabled.
+.TP
+.BI cqe\-size \ N
+Changes the size of completion queue event.
 .RE
 .TP
 .B \-i \-\-driver
diff --git a/ethtool.c b/ethtool.c
index c58c73b..ef4e4c6 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -5734,6 +5734,7 @@ static const struct option args[] = {
 			  "		[ tx N ]\n"
 			  "		[ rx-buf-len N]\n"
 			  "		[ tx-push on|off]\n"
+			  "             [ cqe-size N]\n"
 	},
 	{
 		.opts	= "-k|--show-features|--show-offload",
diff --git a/netlink/rings.c b/netlink/rings.c
index 3718c10..5999247 100644
--- a/netlink/rings.c
+++ b/netlink/rings.c
@@ -48,6 +48,7 @@ int rings_reply_cb(const struct nlmsghdr *nlhdr, void *data)
 	show_u32(tb[ETHTOOL_A_RINGS_TX], "TX:\t\t");
 	show_u32(tb[ETHTOOL_A_RINGS_RX_BUF_LEN], "RX Buf Len:\t\t");
 	show_bool("tx-push", "TX Push:\t%s\n", tb[ETHTOOL_A_RINGS_TX_PUSH]);
+	show_u32(tb[ETHTOOL_A_RINGS_CQE_SIZE], "CQE Size:\t\t");
 
 	return MNL_CB_OK;
 }
@@ -112,6 +113,12 @@ static const struct param_parser sring_params[] = {
 		.handler        = nl_parse_u8bool,
 		.min_argc       = 1,
 	},
+	{
+		.arg            = "cqe-size",
+		.type           = ETHTOOL_A_RINGS_CQE_SIZE,
+		.handler        = nl_parse_direct_u32,
+		.min_argc       = 1,
+	},
 	{}
 };
 
-- 
2.7.4