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From:   Moshe Shemesh <moshe@mellanox.com>
To:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, Jiri Pirko <jiri@nvidia.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Moshe Shemesh <moshe@mellanox.com>
Subject: [PATCH net-next v2 05/16] devlink: Add remote reload stats
Date:   Wed,  7 Oct 2020 09:00:46 +0300
Message-Id: <1602050457-21700-6-git-send-email-moshe@mellanox.com>
In-Reply-To: <1602050457-21700-1-git-send-email-moshe@mellanox.com>
References: <1602050457-21700-1-git-send-email-moshe@mellanox.com>
Precedence: bulk

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>
---
v1 -> v2:
- Add devlink_dev_stats structure to include the stats arrays
- Add comment on remote stats shown and limit unspecified stats
- Add parameters check to devlink_remote_reload_actions_performed()
RFCv5 -> v1:
- Resplit this patch and the previous one by remote/local reload stats
instead of set/get reload stats
- Rename reload_action_stats to reload_stats
RFCv4 -> RFCv5:
- Add remote actions stats
- If devlink reload is not supported, show only remote_stats
RFCv3 -> RFCv4:
- Renamed DEVLINK_ATTR_RELOAD_ACTION_CNT to
  DEVLINK_ATTR_RELOAD_ACTION_STAT
- Add stats per action per limit level
RFCv2 -> RFCv3:
- Add reload actions counters instead of supported reload actions
  (reload actions counters are only for supported action so no need for
   both)
RFCv1 -> RFCv2:
- Removed DEVLINK_ATTR_RELOAD_DEFAULT_LEVEL
- Removed DEVLINK_ATTR_RELOAD_LEVELS_INFO
- Have actions instead of levels
---
 include/net/devlink.h        |  4 +++
 include/uapi/linux/devlink.h |  1 +
 net/core/devlink.c           | 60 ++++++++++++++++++++++++++++++++----
 3 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index d091c6ba82ce..d2771e57a278 100644
--- a/include/net/devlink.h
+++ b/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);
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 6f4cdb95eaee..b54c8bce4ca8 100644
--- a/include/uapi/linux/devlink.h
+++ b/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 */
 
diff --git a/net/core/devlink.c b/net/core/devlink.c
index a167c3bb468c..dd889334fed9 100644
--- a/net/core/devlink.c
+++ b/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;
 }
-- 
2.18.2