[PATCH net-next 05/16] devlink: Add remote reload stats

From: Moshe Shemesh
Date: Thu Oct 01 2020 - 10:01:15 EST


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_stats:
driver_reinit 2
fw_activate 1
fw_activate_no_reset 0
remote_reload_stats:
driver_reinit 0
fw_activate 0
fw_activate_no_reset 0
pci/0000:82:00.1:
stats:
reload_stats:
driver_reinit 1
fw_activate 0
fw_activate_no_reset 0
remote_reload_stats:
driver_reinit 1
fw_activate 1
fw_activate_no_reset 0

$ devlink dev show -jp
{
"dev": {
"pci/0000:82:00.0": {
"stats": {
"reload_stats": [ {
"driver_reinit": 2
},{
"fw_activate": 1
},{
"fw_activate_no_reset": 0
} ],
"remote_reload_stats": [ {
"driver_reinit": 0
},{
"fw_activate": 0
},{
"fw_activate_no_reset": 0
} ]
}
},
"pci/0000:82:00.1": {
"stats": {
"reload_stats": [ {
"driver_reinit": 1
},{
"fw_activate": 0
},{
"fw_activate_no_reset": 0
} ],
"remote_reload_stats": [ {
"driver_reinit": 1
},{
"fw_activate": 1
},{
"fw_activate_no_reset": 0
} ]
}
}
}
}

Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxxxx>
---
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 | 1 +
include/uapi/linux/devlink.h | 1 +
net/core/devlink.c | 49 +++++++++++++++++++++++++++++++-----
3 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 0f3bd23b6c04..a4ccb83bbd2c 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -42,6 +42,7 @@ struct devlink {
const struct devlink_ops *ops;
struct xarray snapshot_ids;
u32 reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
+ u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
struct device *dev;
possible_net_t _net;
struct mutex lock; /* Serializes access to devlink instance specific objects such as
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 97e0137f6201..f9887d8afdc7 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -530,6 +530,7 @@ enum devlink_attr {
DEVLINK_ATTR_RELOAD_STATS, /* nested */
DEVLINK_ATTR_RELOAD_STATS_ENTRY, /* nested */
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 05516f1e4c3e..3b6bd3b4d346 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -523,28 +523,35 @@ 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 &&
+ 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->reload_stats[stat_idx];
+ if (!is_remote)
+ value = devlink->reload_stats[stat_idx];
+ else
+ value = devlink->remote_reload_stats[stat_idx];
if (devlink_reload_stat_put(msg, i, j, value))
goto nla_put_failure;
}
@@ -577,7 +584,9 @@ 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);
@@ -3100,15 +3109,40 @@ devlink_reload_stats_update(struct devlink *devlink, enum devlink_reload_limit l
__devlink_reload_stats_update(devlink, devlink->reload_stats, limit, 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,
+ unsigned long actions_performed)
+{
+ __devlink_reload_stats_update(devlink, devlink->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,
struct netlink_ext_ack *extack, unsigned long *actions_performed)
{
+ u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
int err;

if (!devlink->reload_enabled)
return -EOPNOTSUPP;

+ memcpy(remote_reload_stats, devlink->remote_reload_stats, sizeof(remote_reload_stats));
err = devlink->ops->reload_down(devlink, !!dest_net, action, limit, extack);
if (err)
return err;
@@ -3122,6 +3156,9 @@ static int devlink_reload(struct devlink *devlink, struct net *dest_net,
return err;

WARN_ON(!test_bit(action, actions_performed));
+ /* Catch driver on updating the remote action within devlink reload */
+ WARN_ON(memcmp(remote_reload_stats, devlink->remote_reload_stats,
+ sizeof(remote_reload_stats)));
devlink_reload_stats_update(devlink, limit, *actions_performed);
return 0;
}
--
2.18.2