sched: act: allow user to specify type of HW stats for a filter

Currently, user who is adding an action expects HW to report stats,
however it does not have exact expectations about the stats types.
That is aligned with TCA_ACT_HW_STATS_TYPE_ANY.

Allow user to specify the type of HW stats for an action and require it.

Pass the information down to flow_offload layer.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/act_api.h

@@ -41,6 +41,7 @@ struct tc_action {
 	struct tc_cookie	__rcu *act_cookie;
 	struct tcf_chain	__rcu *goto_chain;
 	u32			tcfa_flags;
+	u8			hw_stats_type;
 };
 #define tcf_index	common.tcfa_index
 #define tcf_refcnt	common.tcfa_refcnt
@@ -52,6 +53,9 @@ struct tc_action {
 #define tcf_rate_est	common.tcfa_rate_est
 #define tcf_lock	common.tcfa_lock
 
+#define TCA_ACT_HW_STATS_TYPE_ANY (TCA_ACT_HW_STATS_TYPE_IMMEDIATE | \
+				   TCA_ACT_HW_STATS_TYPE_DELAYED)
+
 /* Update lastuse only if needed, to avoid dirtying a cache line.
  * We use a temp variable to avoid fetching jiffies twice.
  */

include/uapi/linux/pkt_cls.h

@@ -17,6 +17,7 @@ enum {
 	TCA_ACT_PAD,
 	TCA_ACT_COOKIE,
 	TCA_ACT_FLAGS,
+	TCA_ACT_HW_STATS_TYPE,
 	__TCA_ACT_MAX
 };
 
@@ -24,6 +25,27 @@ enum {
 					 * actions stats.
 					 */
 
+/* tca HW stats type
+ * When user does not pass the attribute, he does not care.
+ * It is the same as if he would pass the attribute with
+ * all supported bits set.
+ * In case no bits are set, user is not interested in getting any HW statistics.
+ */
+#define TCA_ACT_HW_STATS_TYPE_IMMEDIATE (1 << 0) /* Means that in dump, user
+						  * gets the current HW stats
+						  * state from the device
+						  * queried at the dump time.
+						  */
+#define TCA_ACT_HW_STATS_TYPE_DELAYED (1 << 1) /* 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.
+						*/
+
 #define TCA_ACT_MAX __TCA_ACT_MAX
 #define TCA_OLD_COMPAT (TCA_ACT_MAX+1)
 #define TCA_ACT_MAX_PRIO 32

net/sched/act_api.c

@@ -185,6 +185,7 @@ static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
 	return  nla_total_size(0) /* action number nested */
 		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
 		+ cookie_len /* TCA_ACT_COOKIE */
+		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS_TYPE */
 		+ nla_total_size(0) /* TCA_ACT_STATS nested */
 		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
 		/* TCA_STATS_BASIC */
@@ -788,6 +789,17 @@ tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 	}
 	rcu_read_unlock();
 
+	if (a->hw_stats_type != TCA_ACT_HW_STATS_TYPE_ANY) {
+		struct nla_bitfield32 hw_stats_type = {
+			a->hw_stats_type,
+			TCA_ACT_HW_STATS_TYPE_ANY,
+		};
+
+		if (nla_put(skb, TCA_ACT_HW_STATS_TYPE, sizeof(hw_stats_type),
+			    &hw_stats_type))
+			goto nla_put_failure;
+	}
+
 	if (a->tcfa_flags) {
 		struct nla_bitfield32 flags = { a->tcfa_flags,
 						a->tcfa_flags, };
@@ -854,7 +866,23 @@ static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 	return c;
 }
 
+static u8 tcf_action_hw_stats_type_get(struct nlattr *hw_stats_type_attr)
+{
+	struct nla_bitfield32 hw_stats_type_bf;
+
+	/* If the user did not pass the attr, that means he does
+	 * not care about the type. Return "any" in that case
+	 * which is setting on all supported types.
+	 */
+	if (!hw_stats_type_attr)
+		return TCA_ACT_HW_STATS_TYPE_ANY;
+	hw_stats_type_bf = nla_get_bitfield32(hw_stats_type_attr);
+	return hw_stats_type_bf.value;
+}
+
 static const u32 tca_act_flags_allowed = TCA_ACT_FLAGS_NO_PERCPU_STATS;
+static const u32 tca_act_hw_stats_type_allowed = TCA_ACT_HW_STATS_TYPE_ANY;
+
 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 	[TCA_ACT_KIND]		= { .type = NLA_STRING },
 	[TCA_ACT_INDEX]		= { .type = NLA_U32 },
@@ -863,6 +891,8 @@ static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
 	[TCA_ACT_OPTIONS]	= { .type = NLA_NESTED },
 	[TCA_ACT_FLAGS]		= { .type = NLA_BITFIELD32,
 				    .validation_data = &tca_act_flags_allowed },
+	[TCA_ACT_HW_STATS_TYPE]	= { .type = NLA_BITFIELD32,
+				    .validation_data = &tca_act_hw_stats_type_allowed },
 };
 
 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
@@ -871,6 +901,7 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 				    bool rtnl_held,
 				    struct netlink_ext_ack *extack)
 {
+	u8 hw_stats_type = TCA_ACT_HW_STATS_TYPE_ANY;
 	struct nla_bitfield32 flags = { 0, 0 };
 	struct tc_action *a;
 	struct tc_action_ops *a_o;
@@ -903,6 +934,8 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 				goto err_out;
 			}
 		}
+		hw_stats_type =
+			tcf_action_hw_stats_type_get(tb[TCA_ACT_HW_STATS_TYPE]);
 		if (tb[TCA_ACT_FLAGS])
 			flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
 	} else {
@@ -953,6 +986,9 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 	if (!name && tb[TCA_ACT_COOKIE])
 		tcf_set_action_cookie(&a->act_cookie, cookie);
 
+	if (!name)
+		a->hw_stats_type = hw_stats_type;
+
 	/* module count goes up only when brand new policy is created
 	 * if it exists and is only bound to in a_o->init() then
 	 * ACT_P_CREATED is not returned (a zero is).

net/sched/cls_api.c

@@ -3464,6 +3464,10 @@ int tc_setup_flow_action(struct flow_action *flow_action,
 	struct tc_action *act;
 	int i, j, k, err = 0;
 
+	BUILD_BUG_ON(TCA_ACT_HW_STATS_TYPE_ANY != FLOW_ACTION_HW_STATS_TYPE_ANY);
+	BUILD_BUG_ON(TCA_ACT_HW_STATS_TYPE_IMMEDIATE != FLOW_ACTION_HW_STATS_TYPE_IMMEDIATE);
+	BUILD_BUG_ON(TCA_ACT_HW_STATS_TYPE_DELAYED != FLOW_ACTION_HW_STATS_TYPE_DELAYED);
+
 	if (!exts)
 		return 0;
 
@@ -3476,6 +3480,9 @@ int tc_setup_flow_action(struct flow_action *flow_action,
 		err = tcf_act_get_cookie(entry, act);
 		if (err)
 			goto err_out_locked;
+
+		entry->hw_stats_type = act->hw_stats_type;
+
 		if (is_tcf_gact_ok(act)) {
 			entry->id = FLOW_ACTION_ACCEPT;
 		} else if (is_tcf_gact_shot(act)) {