From c25031e993440debdd530278ce2171ce477df029 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Mon, 29 Apr 2019 15:48:33 -0700 Subject: [PATCH] taprio: Add support for cycle-time-extension IEEE 802.1Q-2018 defines the concept of a cycle-time-extension, so the last entry of a schedule before the start of a new schedule can be extended, so "too-short" entries can be avoided. Signed-off-by: Vinicius Costa Gomes Signed-off-by: David S. Miller --- include/uapi/linux/pkt_sched.h | 1 + net/sched/sch_taprio.c | 35 ++++++++++++++++++++++++++++------ 2 files changed, 30 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 7a32276838e1..8b2f993cbb77 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -1168,6 +1168,7 @@ enum { TCA_TAPRIO_PAD, TCA_TAPRIO_ATTR_ADMIN_SCHED, /* The admin sched, only used in dump */ TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME, /* s64 */ + TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION, /* s64 */ __TCA_TAPRIO_ATTR_MAX, }; diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 6b37ffda23ec..539677120b9f 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -48,6 +48,7 @@ struct sched_gate_list { size_t num_entries; ktime_t cycle_close_time; s64 cycle_time; + s64 cycle_time_extension; s64 base_time; }; @@ -290,7 +291,7 @@ static bool should_change_schedules(const struct sched_gate_list *admin, const struct sched_gate_list *oper, ktime_t close_time) { - ktime_t next_base_time; + ktime_t next_base_time, extension_time; if (!admin) return false; @@ -303,6 +304,20 @@ static bool should_change_schedules(const struct sched_gate_list *admin, if (ktime_compare(next_base_time, close_time) <= 0) return true; + /* This is the cycle_time_extension case, if the close_time + * plus the amount that can be extended would fall after the + * next schedule base_time, we can extend the current schedule + * for that amount. + */ + extension_time = ktime_add_ns(close_time, oper->cycle_time_extension); + + /* FIXME: the IEEE 802.1Q-2018 Specification isn't clear about + * how precisely the extension should be made. So after + * conformance testing, this logic may change. + */ + if (ktime_compare(next_base_time, extension_time) <= 0) + return true; + return false; } @@ -390,11 +405,12 @@ static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { [TCA_TAPRIO_ATTR_PRIOMAP] = { .len = sizeof(struct tc_mqprio_qopt) }, - [TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST] = { .type = NLA_NESTED }, - [TCA_TAPRIO_ATTR_SCHED_BASE_TIME] = { .type = NLA_S64 }, - [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY] = { .type = NLA_NESTED }, - [TCA_TAPRIO_ATTR_SCHED_CLOCKID] = { .type = NLA_S32 }, - [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = { .type = NLA_S64 }, + [TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST] = { .type = NLA_NESTED }, + [TCA_TAPRIO_ATTR_SCHED_BASE_TIME] = { .type = NLA_S64 }, + [TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY] = { .type = NLA_NESTED }, + [TCA_TAPRIO_ATTR_SCHED_CLOCKID] = { .type = NLA_S32 }, + [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = { .type = NLA_S64 }, + [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 }, }; static int fill_sched_entry(struct nlattr **tb, struct sched_entry *entry, @@ -496,6 +512,9 @@ static int parse_taprio_schedule(struct nlattr **tb, if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]) new->base_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]); + if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]) + new->cycle_time_extension = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]); + if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]) new->cycle_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]); @@ -1008,6 +1027,10 @@ static int dump_schedule(struct sk_buff *msg, root->cycle_time, TCA_TAPRIO_PAD)) return -1; + if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION, + root->cycle_time_extension, TCA_TAPRIO_PAD)) + return -1; + entry_list = nla_nest_start_noflag(msg, TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST); if (!entry_list) -- 2.30.2