[patch net-next 10/10] sched: cls_flower: allow user to specify type of HW stats for a filter

[Jiri Pirko <jiri@resnulli.us>]

From: Jiri Pirko <jiri@mellanox.com>

Currently, user who is adding a filter expects HW report stats, however
it does not have exact expectations about the stats types. That is
aligned with TCA_CLS_HW_STATS_TYPE_ANY.

Allow user to specify type of HW stats for a filter and require a type.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/pkt_cls.h        | 28 ++++++++++++++++++++++++++++
 include/uapi/linux/pkt_cls.h | 27 +++++++++++++++++++++++++++
 net/sched/cls_flower.c       | 12 ++++++++++++
 3 files changed, 67 insertions(+)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index d3d90f714a66..18044ea7c246 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -631,6 +631,34 @@ static inline bool tc_in_hw(u32 flags)
 	return (flags & TCA_CLS_FLAGS_IN_HW) ? true : false;
 }
 
+static inline enum tca_cls_hw_stats_type
+tc_hw_stats_type_get(struct nlattr *hw_stats_type_attr)
+{
+	/* If the user did not pass the attr, that means he does
+	 * not care about the type. Return "any" in that case.
+	 */
+	return hw_stats_type_attr ? nla_get_u8(hw_stats_type_attr) :
+				    TCA_CLS_HW_STATS_TYPE_ANY;
+}
+
+static inline enum flow_cls_hw_stats_type
+tc_flow_cls_hw_stats_type(enum tca_cls_hw_stats_type hw_stats_type)
+{
+	switch (hw_stats_type) {
+	default:
+		WARN_ON(1);
+		/* fall-through */
+	case TCA_CLS_HW_STATS_TYPE_ANY:
+		return FLOW_CLS_HW_STATS_TYPE_ANY;
+	case TCA_CLS_HW_STATS_TYPE_IMMEDIATE:
+		return FLOW_CLS_HW_STATS_TYPE_IMMEDIATE;
+	case TCA_CLS_HW_STATS_TYPE_DELAYED:
+		return FLOW_CLS_HW_STATS_TYPE_DELAYED;
+	case TCA_CLS_HW_STATS_TYPE_DISABLED:
+		return FLOW_CLS_HW_STATS_TYPE_DISABLED;
+	}
+}
+
 static inline void
 tc_cls_common_offload_init(struct flow_cls_common_offload *cls_common,
 			   const struct tcf_proto *tp, u32 flags,
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index 449a63971451..7f89954c2998 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -180,6 +180,31 @@ enum {
 #define TCA_CLS_FLAGS_NOT_IN_HW (1 << 3) /* filter isn't offloaded to HW */
 #define TCA_CLS_FLAGS_VERBOSE	(1 << 4) /* verbose logging */
 
+/* tca HW stats type */
+enum tca_cls_hw_stats_type {
+	TCA_CLS_HW_STATS_TYPE_ANY, /* User does not care, it's default
+				    * when user does not pass the attr.
+				    * Instructs the driver that user does not
+				    * care if the HW stats are "immediate"
+				    * or "delayed".
+				    */
+	TCA_CLS_HW_STATS_TYPE_IMMEDIATE, /* Means that in dump, user gets
+					  * the current HW stats state from
+					  * the device queried at the dump time.
+					  */
+	TCA_CLS_HW_STATS_TYPE_DELAYED, /* Means that in dump, user gets
+					* HW stats that might be out of date
+					* for some time, maybe couple of
+					* seconds. This is the case when driver
+					* polls stats updates periodically
+					* or when it gets async stats update
+					* from the device.
+					*/
+	TCA_CLS_HW_STATS_TYPE_DISABLED, /* User is not interested in getting
+					 * any HW statistics.
+					 */
+};
+
 /* U32 filters */
 
 #define TC_U32_HTID(h) ((h)&0xFFF00000)
@@ -553,6 +578,8 @@ enum {
 	TCA_FLOWER_KEY_CT_LABELS,	/* u128 */
 	TCA_FLOWER_KEY_CT_LABELS_MASK,	/* u128 */
 
+	TCA_FLOWER_HW_STATS_TYPE,	/* u8 */
+
 	__TCA_FLOWER_MAX,
 };
 
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 726fc9c5910f..91171266ac26 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -113,6 +113,7 @@ struct cls_fl_filter {
 	u32 handle;
 	u32 flags;
 	u32 in_hw_count;
+	enum tca_cls_hw_stats_type hw_stats_type;
 	struct rcu_work rwork;
 	struct net_device *hw_dev;
 	/* Flower classifier is unlocked, which means that its reference counter
@@ -442,6 +443,8 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
 		return -ENOMEM;
 
 	tc_cls_common_offload_init(&cls_flower.common, tp, f->flags, extack);
+	cls_flower.common.hw_stats_type =
+		tc_flow_cls_hw_stats_type(f->hw_stats_type);
 	cls_flower.command = FLOW_CLS_REPLACE;
 	cls_flower.cookie = (unsigned long) f;
 	cls_flower.rule->match.dissector = &f->mask->dissector;
@@ -691,6 +694,7 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
 	[TCA_FLOWER_KEY_CT_LABELS_MASK]	= { .type = NLA_BINARY,
 					    .len = 128 / BITS_PER_BYTE },
 	[TCA_FLOWER_FLAGS]		= { .type = NLA_U32 },
+	[TCA_FLOWER_HW_STATS_TYPE]	= { .type = NLA_U8 },
 };
 
 static const struct nla_policy
@@ -1774,6 +1778,9 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		}
 	}
 
+	fnew->hw_stats_type =
+		tc_hw_stats_type_get(tb[TCA_FLOWER_HW_STATS_TYPE]);
+
 	err = fl_set_parms(net, tp, fnew, mask, base, tb, tca[TCA_RATE], ovr,
 			   tp->chain->tmplt_priv, rtnl_held, extack);
 	if (err)
@@ -1992,6 +1999,8 @@ static int fl_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
 
 		tc_cls_common_offload_init(&cls_flower.common, tp, f->flags,
 					   extack);
+		cls_flower.common.hw_stats_type =
+			tc_flow_cls_hw_stats_type(f->hw_stats_type);
 		cls_flower.command = add ?
 			FLOW_CLS_REPLACE : FLOW_CLS_DESTROY;
 		cls_flower.cookie = (unsigned long)f;
@@ -2714,6 +2723,9 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
 	if (f->flags && nla_put_u32(skb, TCA_FLOWER_FLAGS, f->flags))
 		goto nla_put_failure_locked;
 
+	if (nla_put_u8(skb, TCA_FLOWER_HW_STATS_TYPE, f->hw_stats_type))
+		goto nla_put_failure_locked;
+
 	spin_unlock(&tp->lock);
 
 	if (!skip_hw)
-- 
2.21.1