[RFC net-next 1/2] ethtool: add support for controling the type of adaptive coalescing

[Huazhong Tan <tanhuazhong@huawei.com>]

Since the information whether the adaptive behavior is implemented
by DIM or driver custom is useful, so add new attribute to
ETHTOOL_MSG_COALESCE_GET/ETHTOOL_MSG_COALESCE_SET commands to control
the type of adaptive coalescing.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
---
 include/linux/ethtool.h              |  1 +
 include/uapi/linux/ethtool.h         |  2 ++
 include/uapi/linux/ethtool_netlink.h |  1 +
 net/ethtool/coalesce.c               | 11 +++++++++--
 net/ethtool/netlink.h                |  2 +-
 5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 6408b44..f57cb92 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -215,6 +215,7 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
 #define ETHTOOL_COALESCE_TX_USECS_HIGH		BIT(19)
 #define ETHTOOL_COALESCE_TX_MAX_FRAMES_HIGH	BIT(20)
 #define ETHTOOL_COALESCE_RATE_SAMPLE_INTERVAL	BIT(21)
+#define ETHTOOL_COALESCE_USE_DIM		BIT(22)
 
 #define ETHTOOL_COALESCE_USECS						\
 	(ETHTOOL_COALESCE_RX_USECS | ETHTOOL_COALESCE_TX_USECS)
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 9ca87bc..afd8de2 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -433,6 +433,7 @@ struct ethtool_modinfo {
  *	a TX interrupt, when the packet rate is above @pkt_rate_high.
  * @rate_sample_interval: How often to do adaptive coalescing packet rate
  *	sampling, measured in seconds.  Must not be zero.
+ * @use_dim: Use DIM for IRQ coalescing, if adaptive coalescing is enabled.
  *
  * Each pair of (usecs, max_frames) fields specifies that interrupts
  * should be coalesced until
@@ -483,6 +484,7 @@ struct ethtool_coalesce {
 	__u32	tx_coalesce_usecs_high;
 	__u32	tx_max_coalesced_frames_high;
 	__u32	rate_sample_interval;
+	__u32	use_dim;
 };
 
 /**
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index e2bf36e..e3458d9 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -366,6 +366,7 @@ enum {
 	ETHTOOL_A_COALESCE_TX_USECS_HIGH,		/* u32 */
 	ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH,		/* u32 */
 	ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL,	/* u32 */
+	ETHTOOL_A_COALESCE_USE_DIM,			/* u8 */
 
 	/* add new constants above here */
 	__ETHTOOL_A_COALESCE_CNT,
diff --git a/net/ethtool/coalesce.c b/net/ethtool/coalesce.c
index 1d6bc13..f12e5de 100644
--- a/net/ethtool/coalesce.c
+++ b/net/ethtool/coalesce.c
@@ -50,6 +50,7 @@ __CHECK_SUPPORTED_OFFSET(COALESCE_RX_MAX_FRAMES_HIGH);
 __CHECK_SUPPORTED_OFFSET(COALESCE_TX_USECS_HIGH);
 __CHECK_SUPPORTED_OFFSET(COALESCE_TX_MAX_FRAMES_HIGH);
 __CHECK_SUPPORTED_OFFSET(COALESCE_RATE_SAMPLE_INTERVAL);
+__CHECK_SUPPORTED_OFFSET(COALESCE_USE_DIM);
 
 const struct nla_policy ethnl_coalesce_get_policy[] = {
 	[ETHTOOL_A_COALESCE_HEADER]		=
@@ -100,7 +101,8 @@ static int coalesce_reply_size(const struct ethnl_req_info *req_base,
 	       nla_total_size(sizeof(u32)) +	/* _RX_MAX_FRAMES_HIGH */
 	       nla_total_size(sizeof(u32)) +	/* _TX_USECS_HIGH */
 	       nla_total_size(sizeof(u32)) +	/* _TX_MAX_FRAMES_HIGH */
-	       nla_total_size(sizeof(u32));	/* _RATE_SAMPLE_INTERVAL */
+	       nla_total_size(sizeof(u32)) +	/* _RATE_SAMPLE_INTERVAL */
+	       nla_total_size(sizeof(u8));	/* _USE_DIM */
 }
 
 static bool coalesce_put_u32(struct sk_buff *skb, u16 attr_type, u32 val,
@@ -170,7 +172,9 @@ static int coalesce_fill_reply(struct sk_buff *skb,
 	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH,
 			     coal->tx_max_coalesced_frames_high, supported) ||
 	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL,
-			     coal->rate_sample_interval, supported))
+			     coal->rate_sample_interval, supported) ||
+	    coalesce_put_bool(skb, ETHTOOL_A_COALESCE_USE_DIM,
+			      coal->use_dim, supported))
 		return -EMSGSIZE;
 
 	return 0;
@@ -215,6 +219,7 @@ const struct nla_policy ethnl_coalesce_set_policy[] = {
 	[ETHTOOL_A_COALESCE_TX_USECS_HIGH]	= { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH]	= { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL] = { .type = NLA_U32 },
+	[ETHTOOL_A_COALESCE_USE_DIM]		= { .type = NLA_U8 },
 };
 
 int ethnl_set_coalesce(struct sk_buff *skb, struct genl_info *info)
@@ -303,6 +308,8 @@ int ethnl_set_coalesce(struct sk_buff *skb, struct genl_info *info)
 			 tb[ETHTOOL_A_COALESCE_TX_MAX_FRAMES_HIGH], &mod);
 	ethnl_update_u32(&coalesce.rate_sample_interval,
 			 tb[ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL], &mod);
+	ethnl_update_bool32(&coalesce.use_dim,
+			    tb[ETHTOOL_A_COALESCE_USE_DIM], &mod);
 	ret = 0;
 	if (!mod)
 		goto out_ops;
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index d8efec5..e63f44a 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -366,7 +366,7 @@ extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_TX + 1];
 extern const struct nla_policy ethnl_channels_get_policy[ETHTOOL_A_CHANNELS_HEADER + 1];
 extern const struct nla_policy ethnl_channels_set_policy[ETHTOOL_A_CHANNELS_COMBINED_COUNT + 1];
 extern const struct nla_policy ethnl_coalesce_get_policy[ETHTOOL_A_COALESCE_HEADER + 1];
-extern const struct nla_policy ethnl_coalesce_set_policy[ETHTOOL_A_COALESCE_RATE_SAMPLE_INTERVAL + 1];
+extern const struct nla_policy ethnl_coalesce_set_policy[ETHTOOL_A_COALESCE_USE_DIM + 1];
 extern const struct nla_policy ethnl_pause_get_policy[ETHTOOL_A_PAUSE_HEADER + 1];
 extern const struct nla_policy ethnl_pause_set_policy[ETHTOOL_A_PAUSE_TX + 1];
 extern const struct nla_policy ethnl_eee_get_policy[ETHTOOL_A_EEE_HEADER + 1];
-- 
2.7.4