net: sched: gred: store red flags per virtual queue

Right now ECN marking and HARD drop (the common RED flags) can only
be configured for the entire Qdisc.  In preparation for per-vq flags
store the values in the virtual queue structure.  Setting per-vq
flags will only be allowed when no flags are set for the entire Qdisc.
For the new flags we will also make sure undefined bits are 0.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index dc09a32c4b4f4fb8561acd6119372ba37e93fa02..47133106c7e28d7449cc2ff7ef816da1a7212622 100644 (file)
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -29,12 +29,15 @@
 #define GRED_DEF_PRIO (MAX_DPs / 2)
 #define GRED_VQ_MASK (MAX_DPs - 1)
 
+#define GRED_VQ_RED_FLAGS      (TC_RED_ECN | TC_RED_HARDDROP)
+
 struct gred_sched_data;
 struct gred_sched;
 
 struct gred_sched_data {
        u32             limit;          /* HARD maximal queue length    */
        u32             DP;             /* the drop parameters */
+       u32             red_flags;      /* virtualQ version of red_flags */
        u64             bytesin;        /* bytes seen on virtualQ so far*/
        u32             packetsin;      /* packets seen on virtualQ so far*/
        u32             backlog;        /* bytes on the virtualQ */
@@ -139,14 +142,14 @@ static inline void gred_store_wred_set(struct gred_sched *table,
        table->wred_set.qidlestart = q->vars.qidlestart;
 }
 
-static inline int gred_use_ecn(struct gred_sched *t)
+static int gred_use_ecn(struct gred_sched_data *q)
 {
-       return t->red_flags & TC_RED_ECN;
+       return q->red_flags & TC_RED_ECN;
 }
 
-static inline int gred_use_harddrop(struct gred_sched *t)
+static int gred_use_harddrop(struct gred_sched_data *q)
 {
-       return t->red_flags & TC_RED_HARDDROP;
+       return q->red_flags & TC_RED_HARDDROP;
 }
 
 static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
@@ -212,7 +215,7 @@ static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 
        case RED_PROB_MARK:
                qdisc_qstats_overlimit(sch);
-               if (!gred_use_ecn(t) || !INET_ECN_set_ce(skb)) {
+               if (!gred_use_ecn(q) || !INET_ECN_set_ce(skb)) {
                        q->stats.prob_drop++;
                        goto congestion_drop;
                }
@@ -222,7 +225,7 @@ static int gred_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 
        case RED_HARD_MARK:
                qdisc_qstats_overlimit(sch);
-               if (gred_use_harddrop(t) || !gred_use_ecn(t) ||
+               if (gred_use_harddrop(q) || !gred_use_ecn(q) ||
                    !INET_ECN_set_ce(skb)) {
                        q->stats.forced_drop++;
                        goto congestion_drop;
@@ -305,6 +308,7 @@ static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
 {
        struct gred_sched *table = qdisc_priv(sch);
        struct tc_gred_sopt *sopt;
+       bool red_flags_changed;
        int i;
 
        if (!dps)
@@ -329,6 +333,7 @@ static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
        sch_tree_lock(sch);
        table->DPs = sopt->DPs;
        table->def = sopt->def_DP;
+       red_flags_changed = table->red_flags != sopt->flags;
        table->red_flags = sopt->flags;
 
        /*
@@ -348,6 +353,12 @@ static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
                gred_disable_wred_mode(table);
        }
 
+       if (red_flags_changed)
+               for (i = 0; i < table->DPs; i++)
+                       if (table->tab[i])
+                               table->tab[i]->red_flags =
+                                       table->red_flags & GRED_VQ_RED_FLAGS;
+
        for (i = table->DPs; i < MAX_DPs; i++) {
                if (table->tab[i]) {
                        pr_warn("GRED: Warning: Destroying shadowed VQ 0x%x\n",
@@ -379,6 +390,7 @@ static inline int gred_change_vq(struct Qdisc *sch, int dp,
                *prealloc = NULL;
                if (!q)
                        return -ENOMEM;
+               q->red_flags = table->red_flags & GRED_VQ_RED_FLAGS;
        }
 
        q->DP = dp;