[PATCH net-next 02/11] net: core: devlink: add dropped stats traps field

Oleksandr Mazur
2021-06-09T15:16:43Z

Whenever query statistics is issued for trap, devlink subsystem
would also fill-in statistics 'dropped' field. This field indicates
the number of packets HW dropped and failed to report to the device driver,
and thus - to the devlink subsystem itself.
In case if device driver didn't register callback for hard drop
statistics querying, 'dropped' field will be omitted and not filled.

Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
---
include/net/devlink.h | 10 ++++++++
net/core/devlink.c | 53 +++++++++++++++++++++++++++++++++++++++----
2 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 8def0f7365da..b8c6bac067a6 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1326,6 +1326,16 @@ struct devlink_ops {
const struct devlink_trap_group *group,
enum devlink_trap_action action,
struct netlink_ext_ack *extack);
+ /**
+ * @trap_drop_counter_get: Trap drop counter get function.
+ *
+ * Should be used by device drivers to report number of packets
+ * that have been dropped, and cannot be passed to the devlink
+ * subsystem by the underlying device.
+ */
+ int (*trap_drop_counter_get)(struct devlink *devlink,
+ const struct devlink_trap *trap,
+ u64 *p_drops);
/**
* @trap_policer_init: Trap policer initialization function.
*
diff --git a/net/core/devlink.c b/net/core/devlink.c
index e43ffc1891a4..2baf8720bb48 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -6995,8 +6995,9 @@ static void devlink_trap_stats_read(struct devlink_stats __percpu *trap_stats,
}
}

-static int devlink_trap_stats_put(struct sk_buff *msg,
- struct devlink_stats __percpu *trap_stats)
+static int
+devlink_trap_group_stats_put(struct sk_buff *msg,
+ struct devlink_stats __percpu *trap_stats)
{
struct devlink_stats stats;
struct nlattr *attr;
@@ -7024,6 +7025,50 @@ static int devlink_trap_stats_put(struct sk_buff *msg,
return -EMSGSIZE;
}

+static int devlink_trap_stats_put(struct sk_buff *msg, struct devlink *devlink,
+ const struct devlink_trap_item *trap_item)
+{
+ struct devlink_stats stats;
+ struct nlattr *attr;
+ u64 drops = 0;
+ int err;
+
+ if (devlink->ops->trap_drop_counter_get) {
+ err = devlink->ops->trap_drop_counter_get(devlink,
+ trap_item->trap,
+ &drops);
+ if (err)
+ return err;
+ }
+
+ devlink_trap_stats_read(trap_item->stats, &stats);
+
+ attr = nla_nest_start(msg, DEVLINK_ATTR_STATS);
+ if (!attr)
+ return -EMSGSIZE;
+
+ if (devlink->ops->trap_drop_counter_get &&
+ nla_put_u64_64bit(msg, DEVLINK_ATTR_STATS_RX_DROPPED, drops,
+ DEVLINK_ATTR_PAD))
+ goto nla_put_failure;
+
+ if (nla_put_u64_64bit(msg, DEVLINK_ATTR_STATS_RX_PACKETS,
+ stats.rx_packets, DEVLINK_ATTR_PAD))
+ goto nla_put_failure;
+
+ if (nla_put_u64_64bit(msg, DEVLINK_ATTR_STATS_RX_BYTES,
+ stats.rx_bytes, DEVLINK_ATTR_PAD))
+ goto nla_put_failure;
+
+ nla_nest_end(msg, attr);
+
+ return 0;
+
+nla_put_failure:
+ nla_nest_cancel(msg, attr);
+ return -EMSGSIZE;
+}
+
static int devlink_nl_trap_fill(struct sk_buff *msg, struct devlink *devlink,
const struct devlink_trap_item *trap_item,
enum devlink_command cmd, u32 portid, u32 seq,
@@ -7061,7 +7106,7 @@ static int devlink_nl_trap_fill(struct sk_buff *msg, struct devlink *devlink,
if (err)
goto nla_put_failure;

- err = devlink_trap_stats_put(msg, trap_item->stats);
+ err = devlink_trap_stats_put(msg, devlink, trap_item);
if (err)
goto nla_put_failure;

@@ -7278,7 +7323,7 @@ devlink_nl_trap_group_fill(struct sk_buff *msg, struct devlink *devlink,
group_item->policer_item->policer->id))
goto nla_put_failure;

- err = devlink_trap_stats_put(msg, group_item->stats);
+ err = devlink_trap_group_stats_put(msg, group_item->stats);
if (err)
goto nla_put_failure;

--
2.17.1