devlink: Add remote reload stats

Add remote reload stats to hold the history of actions performed due
devlink reload commands initiated by remote host. For example, in case
firmware activation with reset finished successfully but was initiated
by remote host.

The function devlink_remote_reload_actions_performed() is exported to
enable drivers update on remote reload actions performed as it was not
initiated by their own devlink instance.

Expose devlink remote reload stats to the user through devlink dev get
command.

Examples:
$ devlink dev show
pci/0000:82:00.0:
  stats:
      reload:
        driver_reinit 2 fw_activate 1 fw_activate_no_reset 0
      remote_reload:
        driver_reinit 0 fw_activate 0 fw_activate_no_reset 0
pci/0000:82:00.1:
  stats:
      reload:
        driver_reinit 1 fw_activate 0 fw_activate_no_reset 0
      remote_reload:
        driver_reinit 1 fw_activate 1 fw_activate_no_reset 0

$ devlink dev show -jp
{
    "dev": {
        "pci/0000:82:00.0": {
            "stats": {
                "reload": {
                    "driver_reinit": 2,
                    "fw_activate": 1,
                    "fw_activate_no_reset": 0
                },
                "remote_reload": {
                    "driver_reinit": 0,
                    "fw_activate": 0,
                    "fw_activate_no_reset": 0
                }
            }
        },
        "pci/0000:82:00.1": {
            "stats": {
                "reload": {
                    "driver_reinit": 1,
                    "fw_activate": 0,
                    "fw_activate_no_reset": 0
                },
                "remote_reload": {
                    "driver_reinit": 1,
                    "fw_activate": 1,
                    "fw_activate_no_reset": 0
                }
            }
        }
    }
}
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/devlink.h

@@ -25,6 +25,7 @@
 
 struct devlink_dev_stats {
 	u32 reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
+	u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
 };
 
 struct devlink_ops;
@@ -1567,6 +1568,9 @@ void
 devlink_health_reporter_recovery_done(struct devlink_health_reporter *reporter);
 
 bool devlink_is_reload_failed(const struct devlink *devlink);
+void devlink_remote_reload_actions_performed(struct devlink *devlink,
+					     enum devlink_reload_limit limit,
+					     u32 actions_performed);
 
 void devlink_flash_update_begin_notify(struct devlink *devlink);
 void devlink_flash_update_end_notify(struct devlink *devlink);

include/uapi/linux/devlink.h

@@ -525,6 +525,7 @@ enum devlink_attr {
 	DEVLINK_ATTR_RELOAD_STATS_ENTRY,	/* nested */
 	DEVLINK_ATTR_RELOAD_STATS_LIMIT,	/* u8 */
 	DEVLINK_ATTR_RELOAD_STATS_VALUE,	/* u32 */
+	DEVLINK_ATTR_REMOTE_RELOAD_STATS,	/* nested */
 
 	/* add new attributes above here, update the policy in devlink.c */
 

net/core/devlink.c

@@ -538,28 +538,39 @@ static int devlink_reload_stat_put(struct sk_buff *msg, enum devlink_reload_acti
 	return -EMSGSIZE;
 }
 
-static int devlink_reload_stats_put(struct sk_buff *msg, struct devlink *devlink)
+static int devlink_reload_stats_put(struct sk_buff *msg, struct devlink *devlink, bool is_remote)
 {
 	struct nlattr *reload_stats_attr;
 	int i, j, stat_idx;
 	u32 value;
 
-	reload_stats_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_STATS);
+	if (!is_remote)
+		reload_stats_attr = nla_nest_start(msg, DEVLINK_ATTR_RELOAD_STATS);
+	else
+		reload_stats_attr = nla_nest_start(msg, DEVLINK_ATTR_REMOTE_RELOAD_STATS);
 
 	if (!reload_stats_attr)
 		return -EMSGSIZE;
 
 	for (j = 0; j <= DEVLINK_RELOAD_LIMIT_MAX; j++) {
-		if (j != DEVLINK_RELOAD_LIMIT_UNSPEC &&
+		/* Remote stats are shown even if not locally supported. Stats
+		 * of actions with unspecified limit are shown though drivers
+		 * don't need to register unspecified limit.
+		 */
+		if (!is_remote && j != DEVLINK_RELOAD_LIMIT_UNSPEC &&
 		    !devlink_reload_limit_is_supported(devlink, j))
 			continue;
 		for (i = 0; i <= DEVLINK_RELOAD_ACTION_MAX; i++) {
-			if (!devlink_reload_action_is_supported(devlink, i) ||
+			if ((!is_remote && !devlink_reload_action_is_supported(devlink, i)) ||
+			    i == DEVLINK_RELOAD_ACTION_UNSPEC ||
 			    devlink_reload_combination_is_invalid(i, j))
 				continue;
 
 			stat_idx = j * __DEVLINK_RELOAD_ACTION_MAX + i;
-			value = devlink->stats.reload_stats[stat_idx];
+			if (!is_remote)
+				value = devlink->stats.reload_stats[stat_idx];
+			else
+				value = devlink->stats.remote_reload_stats[stat_idx];
 			if (devlink_reload_stat_put(msg, i, j, value))
 				goto nla_put_failure;
 		}
@@ -592,7 +603,9 @@ static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
 	if (!dev_stats)
 		goto nla_put_failure;
 
-	if (devlink_reload_stats_put(msg, devlink))
+	if (devlink_reload_stats_put(msg, devlink, false))
+		goto dev_stats_nest_cancel;
+	if (devlink_reload_stats_put(msg, devlink, true))
 		goto dev_stats_nest_cancel;
 
 	nla_nest_end(msg, dev_stats);
@@ -3110,15 +3123,47 @@ devlink_reload_stats_update(struct devlink *devlink, enum devlink_reload_limit l
 				      actions_performed);
 }
 
+/**
+ *	devlink_remote_reload_actions_performed - Update devlink on reload actions
+ *	  performed which are not a direct result of devlink reload call.
+ *
+ *	This should be called by a driver after performing reload actions in case it was not
+ *	a result of devlink reload call. For example fw_activate was performed as a result
+ *	of devlink reload triggered fw_activate on another host.
+ *	The motivation for this function is to keep data on reload actions performed on this
+ *	function whether it was done due to direct devlink reload call or not.
+ *
+ *	@devlink: devlink
+ *	@limit: reload limit
+ *	@actions_performed: bitmask of actions performed
+ */
+void devlink_remote_reload_actions_performed(struct devlink *devlink,
+					     enum devlink_reload_limit limit,
+					     u32 actions_performed)
+{
+	if (WARN_ON(!actions_performed ||
+		    actions_performed & BIT(DEVLINK_RELOAD_ACTION_UNSPEC) ||
+		    actions_performed >= BIT(__DEVLINK_RELOAD_ACTION_MAX) ||
+		    limit > DEVLINK_RELOAD_LIMIT_MAX))
+		return;
+
+	__devlink_reload_stats_update(devlink, devlink->stats.remote_reload_stats, limit,
+				      actions_performed);
+}
+EXPORT_SYMBOL_GPL(devlink_remote_reload_actions_performed);
+
 static int devlink_reload(struct devlink *devlink, struct net *dest_net,
 			  enum devlink_reload_action action, enum devlink_reload_limit limit,
 			  u32 *actions_performed, struct netlink_ext_ack *extack)
 {
+	u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
 	int err;
 
 	if (!devlink->reload_enabled)
 		return -EOPNOTSUPP;
 
+	memcpy(remote_reload_stats, devlink->stats.remote_reload_stats,
+	       sizeof(remote_reload_stats));
 	err = devlink->ops->reload_down(devlink, !!dest_net, action, limit, extack);
 	if (err)
 		return err;
@@ -3132,6 +3177,9 @@ static int devlink_reload(struct devlink *devlink, struct net *dest_net,
 		return err;
 
 	WARN_ON(!(*actions_performed & BIT(action)));
+	/* Catch driver on updating the remote action within devlink reload */
+	WARN_ON(memcmp(remote_reload_stats, devlink->stats.remote_reload_stats,
+		       sizeof(remote_reload_stats)));
 	devlink_reload_stats_update(devlink, limit, *actions_performed);
 	return 0;
 }