net_sched: add u64 rate to psched_ratecfg_precompute()

Add an extra u64 rate parameter to psched_ratecfg_precompute()
so that some qdisc can opt-in for 64bit rates in the future,
to overcome the ~34 Gbits limit.

psched_ratecfg_getrate() reports a legacy structure to
tc utility, so if actual rate is above the 32bit rate field,
cap it to the 34Gbit limit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 18 insertions, 10 deletions

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index f4eb365f7dcd..d0a6321c302e 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -702,13 +702,20 @@ static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
 }
 
 void psched_ratecfg_precompute(struct psched_ratecfg *r,
-                               const struct tc_ratespec *conf);
+                               const struct tc_ratespec *conf,
+                               u64 rate64);
 
 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
                                           const struct psched_ratecfg *r)
 {
         memset(res, 0, sizeof(*res));
-        res->rate = r->rate_bytes_ps;
+
+        /* legacy struct tc_ratespec has a 32bit @rate field
+         * Qdisc using 64bit rate should add new attributes
+         * in order to maintain compatibility.
+         */
+        res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
+
         res->overhead = r->overhead;
         res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
 }
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index 189e3c5b3d09..272d8e924cf6 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -231,14 +231,14 @@ override:
         }
         if (R_tab) {
                 police->rate_present = true;
-                psched_ratecfg_precompute(&police->rate, &R_tab->rate);
+                psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
                 qdisc_put_rtab(R_tab);
         } else {
                 police->rate_present = false;
         }
         if (P_tab) {
                 police->peak_present = true;
-                psched_ratecfg_precompute(&police->peak, &P_tab->rate);
+                psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
                 qdisc_put_rtab(P_tab);
         } else {
                 police->peak_present = false;
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a74e278654aa..e7121d29c4bd 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -910,11 +910,12 @@ void dev_shutdown(struct net_device *dev)
 }
 
 void psched_ratecfg_precompute(struct psched_ratecfg *r,
-                               const struct tc_ratespec *conf)
+                               const struct tc_ratespec *conf,
+                               u64 rate64)
 {
         memset(r, 0, sizeof(*r));
         r->overhead = conf->overhead;
-        r->rate_bytes_ps = conf->rate;
+        r->rate_bytes_ps = max_t(u64, conf->rate, rate64);
         r->linklayer = (conf->linklayer & TC_LINKLAYER_MASK);
         r->mult = 1;
         /*
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 863846cc5513..6b126f6c9957 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1491,8 +1491,8 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
                         cl->prio = TC_HTB_NUMPRIO - 1;
         }
 
-        psched_ratecfg_precompute(&cl->rate, &hopt->rate);
-        psched_ratecfg_precompute(&cl->ceil, &hopt->ceil);
+        psched_ratecfg_precompute(&cl->rate, &hopt->rate, 0);
+        psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, 0);
 
         cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
         cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer);
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index 1aaf1b6e51a2..b0571224f3c9 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -341,9 +341,9 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt)
         q->tokens = q->buffer;
         q->ptokens = q->mtu;
 
-        psched_ratecfg_precompute(&q->rate, &rtab->rate);
+        psched_ratecfg_precompute(&q->rate, &rtab->rate, 0);
         if (ptab) {
-                psched_ratecfg_precompute(&q->peak, &ptab->rate);
+                psched_ratecfg_precompute(&q->peak, &ptab->rate, 0);
                 q->peak_present = true;
         } else {
                 q->peak_present = false;