[PATCH net-next v6 1/3] net: ethtool: add ethtool COALESCE_RX_CQE_FRAMES/NSECS

[Haiyang Zhang <haiyangz@linux.microsoft.com>]

From: Haiyang Zhang <haiyangz@microsoft.com>

Add two parameters for drivers supporting Rx CQE coalescing /
descriptor writeback.

ETHTOOL_A_COALESCE_RX_CQE_FRAMES:
Maximum number of frames that can be coalesced into a CQE or
writeback.

ETHTOOL_A_COALESCE_RX_CQE_NSECS:
Max time in nanoseconds after the first packet arrival in a
coalesced CQE or writeback to be sent.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
v6:
  Updated comment to include "descriptor writeback", as suggested by
  Jakub Kicinski

---
 Documentation/netlink/specs/ethtool.yaml       |  8 ++++++++
 Documentation/networking/ethtool-netlink.rst   | 11 +++++++++++
 include/linux/ethtool.h                        |  6 +++++-
 include/uapi/linux/ethtool_netlink_generated.h |  2 ++
 net/ethtool/coalesce.c                         | 14 +++++++++++++-
 5 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 4707063af3b4..d254e26c014c 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -861,6 +861,12 @@ attribute-sets:
         name: tx-profile
         type: nest
         nested-attributes: profile
+      -
+        name: rx-cqe-frames
+        type: u32
+      -
+        name: rx-cqe-nsecs
+        type: u32
 
   -
     name: pause-stat
@@ -2257,6 +2263,8 @@ operations:
             - tx-aggr-time-usecs
             - rx-profile
             - tx-profile
+            - rx-cqe-frames
+            - rx-cqe-nsecs
       dump: *coalesce-get-op
     -
       name: coalesce-set
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 32179168eb73..e92abf45faf5 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1076,6 +1076,8 @@ Kernel response contents:
   ``ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS``    u32     time (us), aggr, Tx
   ``ETHTOOL_A_COALESCE_RX_PROFILE``            nested  profile of DIM, Rx
   ``ETHTOOL_A_COALESCE_TX_PROFILE``            nested  profile of DIM, Tx
+  ``ETHTOOL_A_COALESCE_RX_CQE_FRAMES``         u32     max packets, Rx CQE
+  ``ETHTOOL_A_COALESCE_RX_CQE_NSECS``          u32     delay (ns), Rx CQE
   ===========================================  ======  =======================
 
 Attributes are only included in reply if their value is not zero or the
@@ -1109,6 +1111,13 @@ well with frequent small-sized URBs transmissions.
 to DIM parameters, see `Generic Network Dynamic Interrupt Moderation (Net DIM)
 <https://www.kernel.org/doc/Documentation/networking/net_dim.rst>`_.
 
+Rx CQE coalescing allows multiple received packets to be coalesced into a
+single Completion Queue Entry (CQE) or descriptor writeback.
+``ETHTOOL_A_COALESCE_RX_CQE_FRAMES`` describes the maximum number of
+frames that can be coalesced into a CQE or writeback.
+``ETHTOOL_A_COALESCE_RX_CQE_NSECS`` describes max time in nanoseconds after
+the first packet arrival in a coalesced CQE or writeback to be sent.
+
 COALESCE_SET
 ============
 
@@ -1147,6 +1156,8 @@ Request contents:
   ``ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS``    u32     time (us), aggr, Tx
   ``ETHTOOL_A_COALESCE_RX_PROFILE``            nested  profile of DIM, Rx
   ``ETHTOOL_A_COALESCE_TX_PROFILE``            nested  profile of DIM, Tx
+  ``ETHTOOL_A_COALESCE_RX_CQE_FRAMES``         u32     max packets, Rx CQE
+  ``ETHTOOL_A_COALESCE_RX_CQE_NSECS``          u32     delay (ns), Rx CQE
   ===========================================  ======  =======================
 
 Request is rejected if it attributes declared as unsupported by driver (i.e.
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 83c375840835..656d465bcd06 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -332,6 +332,8 @@ struct kernel_ethtool_coalesce {
 	u32 tx_aggr_max_bytes;
 	u32 tx_aggr_max_frames;
 	u32 tx_aggr_time_usecs;
+	u32 rx_cqe_frames;
+	u32 rx_cqe_nsecs;
 };
 
 /**
@@ -380,7 +382,9 @@ bool ethtool_convert_link_mode_to_legacy_u32(u32 *legacy_u32,
 #define ETHTOOL_COALESCE_TX_AGGR_TIME_USECS	BIT(26)
 #define ETHTOOL_COALESCE_RX_PROFILE		BIT(27)
 #define ETHTOOL_COALESCE_TX_PROFILE		BIT(28)
-#define ETHTOOL_COALESCE_ALL_PARAMS		GENMASK(28, 0)
+#define ETHTOOL_COALESCE_RX_CQE_FRAMES		BIT(29)
+#define ETHTOOL_COALESCE_RX_CQE_NSECS		BIT(30)
+#define ETHTOOL_COALESCE_ALL_PARAMS		GENMASK(30, 0)
 
 #define ETHTOOL_COALESCE_USECS						\
 	(ETHTOOL_COALESCE_RX_USECS | ETHTOOL_COALESCE_TX_USECS)
diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index 114b83017297..8134baf7860f 100644
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -371,6 +371,8 @@ enum {
 	ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS,
 	ETHTOOL_A_COALESCE_RX_PROFILE,
 	ETHTOOL_A_COALESCE_TX_PROFILE,
+	ETHTOOL_A_COALESCE_RX_CQE_FRAMES,
+	ETHTOOL_A_COALESCE_RX_CQE_NSECS,
 
 	__ETHTOOL_A_COALESCE_CNT,
 	ETHTOOL_A_COALESCE_MAX = (__ETHTOOL_A_COALESCE_CNT - 1)
diff --git a/net/ethtool/coalesce.c b/net/ethtool/coalesce.c
index 3e18ca1ccc5e..349bb02c517a 100644
--- a/net/ethtool/coalesce.c
+++ b/net/ethtool/coalesce.c
@@ -118,6 +118,8 @@ static int coalesce_reply_size(const struct ethnl_req_info *req_base,
 	       nla_total_size(sizeof(u32)) +	/* _TX_AGGR_MAX_BYTES */
 	       nla_total_size(sizeof(u32)) +	/* _TX_AGGR_MAX_FRAMES */
 	       nla_total_size(sizeof(u32)) +	/* _TX_AGGR_TIME_USECS */
+	       nla_total_size(sizeof(u32)) +	/* _RX_CQE_FRAMES */
+	       nla_total_size(sizeof(u32)) +	/* _RX_CQE_NSECS */
 	       total_modersz * 2;		/* _{R,T}X_PROFILE */
 }
 
@@ -269,7 +271,11 @@ static int coalesce_fill_reply(struct sk_buff *skb,
 	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES,
 			     kcoal->tx_aggr_max_frames, supported) ||
 	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS,
-			     kcoal->tx_aggr_time_usecs, supported))
+			     kcoal->tx_aggr_time_usecs, supported) ||
+	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_RX_CQE_FRAMES,
+			     kcoal->rx_cqe_frames, supported) ||
+	    coalesce_put_u32(skb, ETHTOOL_A_COALESCE_RX_CQE_NSECS,
+			     kcoal->rx_cqe_nsecs, supported))
 		return -EMSGSIZE;
 
 	if (!req_base->dev || !req_base->dev->irq_moder)
@@ -338,6 +344,8 @@ const struct nla_policy ethnl_coalesce_set_policy[] = {
 	[ETHTOOL_A_COALESCE_TX_AGGR_MAX_BYTES] = { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES] = { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS] = { .type = NLA_U32 },
+	[ETHTOOL_A_COALESCE_RX_CQE_FRAMES] = { .type = NLA_U32 },
+	[ETHTOOL_A_COALESCE_RX_CQE_NSECS] = { .type = NLA_U32 },
 	[ETHTOOL_A_COALESCE_RX_PROFILE] =
 		NLA_POLICY_NESTED(coalesce_profile_policy),
 	[ETHTOOL_A_COALESCE_TX_PROFILE] =
@@ -570,6 +578,10 @@ __ethnl_set_coalesce(struct ethnl_req_info *req_info, struct genl_info *info,
 			 tb[ETHTOOL_A_COALESCE_TX_AGGR_MAX_FRAMES], &mod);
 	ethnl_update_u32(&kernel_coalesce.tx_aggr_time_usecs,
 			 tb[ETHTOOL_A_COALESCE_TX_AGGR_TIME_USECS], &mod);
+	ethnl_update_u32(&kernel_coalesce.rx_cqe_frames,
+			 tb[ETHTOOL_A_COALESCE_RX_CQE_FRAMES], &mod);
+	ethnl_update_u32(&kernel_coalesce.rx_cqe_nsecs,
+			 tb[ETHTOOL_A_COALESCE_RX_CQE_NSECS], &mod);
 
 	if (dev->irq_moder && dev->irq_moder->profile_flags & DIM_PROFILE_RX) {
 		ret = ethnl_update_profile(dev, &dev->irq_moder->rx_profile,
-- 
2.34.1