Drivers may need to reset per-device PSP statistics to zero.
Add a reset-stats netlink command and a corresponding optional
driver callback to support this.

Signed-off-by: Akhilesh Samineni <akhilesh.samineni@broadcom.com>
Reviewed-by: Kiran Kella <kiran.kella@broadcom.com>
Reviewed-by: Ajit Kumar Khaparde <ajit.khaparde@broadcom.com>
---
 Documentation/netlink/specs/psp.yaml | 13 +++++++++++++
 include/net/psp/types.h              |  6 ++++++
 include/uapi/linux/psp.h             |  1 +
 net/psp/psp-nl-gen.c                 | 14 ++++++++++++++
 net/psp/psp-nl-gen.h                 |  1 +
 net/psp/psp_nl.c                     | 24 ++++++++++++++++++++++++
 6 files changed, 59 insertions(+)

diff --git a/Documentation/netlink/specs/psp.yaml b/Documentation/netlink/specs/psp.yaml
index f3a57782d2cf..e37ca142af54 100644
--- a/Documentation/netlink/specs/psp.yaml
+++ b/Documentation/netlink/specs/psp.yaml
@@ -272,6 +272,19 @@ operations:
       dump:
         reply: *stats-all
 
+    -
+      name: reset-stats
+      doc: Reset device statistics.
+      attribute-set: dev
+      do:
+        request:
+          attributes:
+            - id
+        reply:
+          attributes: []
+        pre: psp-device-get-locked
+        post: psp-device-unlock
+
 mcast-groups:
   list:
     -
diff --git a/include/net/psp/types.h b/include/net/psp/types.h
index 25a9096d4e7d..7f9924e8ab0d 100644
--- a/include/net/psp/types.h
+++ b/include/net/psp/types.h
@@ -211,6 +211,12 @@ struct psp_dev_ops {
 	 * Stats must be filled in member-by-member, never memset the struct.
 	 */
 	void (*get_stats)(struct psp_dev *psd, struct psp_dev_stats *stats);
+
+	/**
+	 * @reset_stats: reset the statistics
+	 */
+	int (*reset_stats)(struct psp_dev *psd, struct netlink_ext_ack *extack);
+
 };
 
 #endif /* __NET_PSP_H */
diff --git a/include/uapi/linux/psp.h b/include/uapi/linux/psp.h
index a3a336488dc3..6e0c217a8366 100644
--- a/include/uapi/linux/psp.h
+++ b/include/uapi/linux/psp.h
@@ -74,6 +74,7 @@ enum {
 	PSP_CMD_RX_ASSOC,
 	PSP_CMD_TX_ASSOC,
 	PSP_CMD_GET_STATS,
+	PSP_CMD_RESET_STATS,
 
 	__PSP_CMD_MAX,
 	PSP_CMD_MAX = (__PSP_CMD_MAX - 1)
diff --git a/net/psp/psp-nl-gen.c b/net/psp/psp-nl-gen.c
index 22a48d0fa378..c8691f7a61ce 100644
--- a/net/psp/psp-nl-gen.c
+++ b/net/psp/psp-nl-gen.c
@@ -53,6 +53,11 @@ static const struct nla_policy psp_get_stats_nl_policy[PSP_A_STATS_DEV_ID + 1] =
 	[PSP_A_STATS_DEV_ID] = NLA_POLICY_MIN(NLA_U32, 1),
 };
 
+/* PSP_CMD_RESET_STATS - do */
+static const struct nla_policy psp_reset_stats_nl_policy[PSP_A_DEV_ID + 1] = {
+	[PSP_A_DEV_ID] = NLA_POLICY_MIN(NLA_U32, 1),
+};
+
 /* Ops table for psp */
 static const struct genl_split_ops psp_nl_ops[] = {
 	{
@@ -119,6 +124,15 @@ static const struct genl_split_ops psp_nl_ops[] = {
 		.dumpit	= psp_nl_get_stats_dumpit,
 		.flags	= GENL_CMD_CAP_DUMP,
 	},
+	{
+		.cmd		= PSP_CMD_RESET_STATS,
+		.pre_doit	= psp_device_get_locked,
+		.doit		= psp_nl_reset_stats_doit,
+		.post_doit	= psp_device_unlock,
+		.policy		= psp_reset_stats_nl_policy,
+		.maxattr	= PSP_A_DEV_ID,
+		.flags		= GENL_CMD_CAP_DO,
+	},
 };
 
 static const struct genl_multicast_group psp_nl_mcgrps[] = {
diff --git a/net/psp/psp-nl-gen.h b/net/psp/psp-nl-gen.h
index 599c5f1c82f2..67577c898f99 100644
--- a/net/psp/psp-nl-gen.h
+++ b/net/psp/psp-nl-gen.h
@@ -31,6 +31,7 @@ int psp_nl_rx_assoc_doit(struct sk_buff *skb, struct genl_info *info);
 int psp_nl_tx_assoc_doit(struct sk_buff *skb, struct genl_info *info);
 int psp_nl_get_stats_doit(struct sk_buff *skb, struct genl_info *info);
 int psp_nl_get_stats_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int psp_nl_reset_stats_doit(struct sk_buff *skb, struct genl_info *info);
 
 enum {
 	PSP_NLGRP_MGMT,
diff --git a/net/psp/psp_nl.c b/net/psp/psp_nl.c
index 6afd7707ec12..aa8960c8d4d1 100644
--- a/net/psp/psp_nl.c
+++ b/net/psp/psp_nl.c
@@ -277,6 +277,27 @@ int psp_nl_key_rotate_doit(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+int psp_nl_reset_stats_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct psp_dev *psd = info->user_ptr[0];
+	struct sk_buff *rsp;
+	int err;
+
+	if (!psd->ops->reset_stats)
+		return -EOPNOTSUPP;
+
+	rsp = psp_nl_reply_new(info);
+	if (!rsp)
+		return -ENOMEM;
+
+	err = psd->ops->reset_stats(psd, info->extack);
+	if (err)
+		goto err_free_rsp;
+
+	return psp_nl_reply_send(rsp, info);
+
+err_free_rsp:
+	nlmsg_free(rsp);
+	return err;
+}
+
 /* Key etc. */
 
 int psp_assoc_device_get_locked(const struct genl_split_ops *ops,
-- 
2.45.4

Akhilesh Samineni wrote:
> Drivers may need to reset per-device PSP statistics to zero.

The series does not include rationale why this may be needed.

What makes PSP counters special in this regard?

> Add a reset-stats netlink command and a corresponding optional
> driver callback to support this.
> 
> Signed-off-by: Akhilesh Samineni <akhilesh.samineni@broadcom.com>
> Reviewed-by: Kiran Kella <kiran.kella@broadcom.com>
> Reviewed-by: Ajit Kumar Khaparde <ajit.khaparde@broadcom.com>