[patch net-next v3 10/10] sched: act: allow user to specify type of HW stats for a filter

Jiri Pirko
2020-03-06T13:29:15Z

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>
---
v2->v3:
- removed "mixed" bool init
- moved to bitfield
- removed "inline"
v1->v2:
- moved the stats attr from cls_flower (filter) to any action
- rebased on top of cookie offload changes
- adjusted the patch description a bit
---
include/net/act_api.h | 4 ++++
include/uapi/linux/pkt_cls.h | 22 ++++++++++++++++++++++
net/sched/act_api.c | 36 ++++++++++++++++++++++++++++++++++++
net/sched/cls_api.c | 7 +++++++
4 files changed, 69 insertions(+)

diff --git a/include/net/act_api.h b/include/net/act_api.h
index 71347a90a9d1..41337c7fc728 100644
--- a/include/net/act_api.h
+++ b/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.
*/
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index 449a63971451..81cc1a869588 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/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
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 8c466a712cda..aa7b737fed2e 100644
--- a/net/sched/act_api.c
+++ b/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).
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 4e766c5ab77a..e91448640a4f 100644
--- a/net/sched/cls_api.c
+++ b/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)) {
--
2.21.1