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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /net/sched/sch_codel.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'net/sched/sch_codel.c')
| -rw-r--r-- | net/sched/sch_codel.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c new file mode 100644 index 000000000..cacf52449 --- /dev/null +++ b/net/sched/sch_codel.c @@ -0,0 +1,324 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +/* + * Codel - The Controlled-Delay Active Queue Management algorithm + * + * Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com> + * Copyright (C) 2011-2012 Van Jacobson <van@pollere.net> + * + * Implemented on linux by : + * Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net> + * Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com> + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/skbuff.h> +#include <linux/prefetch.h> +#include <net/pkt_sched.h> +#include <net/codel.h> +#include <net/codel_impl.h> +#include <net/codel_qdisc.h> + + +#define DEFAULT_CODEL_LIMIT 1000 + +struct codel_sched_data { + struct codel_params params; + struct codel_vars vars; + struct codel_stats stats; + u32 drop_overlimit; +}; + +/* This is the specific function called from codel_dequeue() + * to dequeue a packet from queue. Note: backlog is handled in + * codel, we dont need to reduce it here. + */ +static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) +{ + struct Qdisc *sch = ctx; + struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); + + if (skb) { + qstats_backlog_sub(sch, qdisc_pkt_len(skb)); + prefetch(&skb->end); /* we'll need skb_shinfo() */ + } + return skb; +} + +static void drop_func(struct sk_buff *skb, void *ctx) +{ + struct Qdisc *sch = ctx; + + qdisc_dequeue_drop(sch, skb, QDISC_DROP_CONGESTED); + qdisc_qstats_drop(sch); +} + +static struct sk_buff *__codel_qdisc_dequeue(struct Qdisc *sch) +{ + struct codel_sched_data *q = qdisc_priv(sch); + struct sk_buff *skb; + + skb = codel_dequeue(sch, &sch->qstats.backlog, &q->params, &q->vars, + &q->stats, qdisc_pkt_len, codel_get_enqueue_time, + drop_func, dequeue_func); + + if (skb) + qdisc_bstats_update(sch, skb); + return skb; +} + +static void codel_dequeue_drop(struct Qdisc *sch) +{ + struct codel_sched_data *q = qdisc_priv(sch); + + if (q->stats.drop_count) { + qdisc_tree_reduce_backlog(sch, q->stats.drop_count, + q->stats.drop_len); + q->stats.drop_count = 0; + q->stats.drop_len = 0; + } +} + +static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch) +{ + struct sk_buff *skb; + + skb = __codel_qdisc_dequeue(sch); + + codel_dequeue_drop(sch); + + return skb; +} + +static struct sk_buff *codel_peek(struct Qdisc *sch) +{ + struct sk_buff *skb = skb_peek(&sch->gso_skb); + + if (!skb) { + skb = __codel_qdisc_dequeue(sch); + + if (skb) { + __skb_queue_head(&sch->gso_skb, skb); + /* it's still part of the queue */ + qdisc_qstats_backlog_inc(sch, skb); + sch->q.qlen++; + } + + codel_dequeue_drop(sch); + } + + return skb; +} + +static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, + struct sk_buff **to_free) +{ + struct codel_sched_data *q; + + if (likely(qdisc_qlen(sch) < sch->limit)) { + codel_set_enqueue_time(skb); + return qdisc_enqueue_tail(skb, sch); + } + q = qdisc_priv(sch); + WRITE_ONCE(q->drop_overlimit, q->drop_overlimit + 1); + return qdisc_drop_reason(skb, sch, to_free, QDISC_DROP_OVERLIMIT); +} + +static const struct nla_policy codel_policy[TCA_CODEL_MAX + 1] = { + [TCA_CODEL_TARGET] = { .type = NLA_U32 }, + [TCA_CODEL_LIMIT] = { .type = NLA_U32 }, + [TCA_CODEL_INTERVAL] = { .type = NLA_U32 }, + [TCA_CODEL_ECN] = { .type = NLA_U32 }, + [TCA_CODEL_CE_THRESHOLD]= { .type = NLA_U32 }, +}; + +static int codel_change(struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + unsigned int dropped_pkts = 0, dropped_bytes = 0; + struct codel_sched_data *q = qdisc_priv(sch); + struct nlattr *tb[TCA_CODEL_MAX + 1]; + int err; + + err = nla_parse_nested_deprecated(tb, TCA_CODEL_MAX, opt, + codel_policy, NULL); + if (err < 0) + return err; + + sch_tree_lock(sch); + + if (tb[TCA_CODEL_TARGET]) { + u32 target = nla_get_u32(tb[TCA_CODEL_TARGET]); + + WRITE_ONCE(q->params.target, + ((u64)target * NSEC_PER_USEC) >> CODEL_SHIFT); + } + + if (tb[TCA_CODEL_CE_THRESHOLD]) { + u64 val = nla_get_u32(tb[TCA_CODEL_CE_THRESHOLD]); + + WRITE_ONCE(q->params.ce_threshold, + (val * NSEC_PER_USEC) >> CODEL_SHIFT); + } + + if (tb[TCA_CODEL_INTERVAL]) { + u32 interval = nla_get_u32(tb[TCA_CODEL_INTERVAL]); + + WRITE_ONCE(q->params.interval, + ((u64)interval * NSEC_PER_USEC) >> CODEL_SHIFT); + } + + if (tb[TCA_CODEL_LIMIT]) + WRITE_ONCE(sch->limit, + nla_get_u32(tb[TCA_CODEL_LIMIT])); + + if (tb[TCA_CODEL_ECN]) + WRITE_ONCE(q->params.ecn, + !!nla_get_u32(tb[TCA_CODEL_ECN])); + + while (sch->q.qlen > sch->limit) { + struct sk_buff *skb = qdisc_dequeue_internal(sch, true); + + if (!skb) + break; + + dropped_pkts++; + dropped_bytes += qdisc_pkt_len(skb); + rtnl_qdisc_drop(skb, sch); + } + qdisc_tree_reduce_backlog(sch, dropped_pkts, dropped_bytes); + + sch_tree_unlock(sch); + return 0; +} + +static int codel_init(struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + struct codel_sched_data *q = qdisc_priv(sch); + + sch->limit = DEFAULT_CODEL_LIMIT; + + codel_params_init(&q->params); + codel_vars_init(&q->vars); + codel_stats_init(&q->stats); + q->params.mtu = psched_mtu(qdisc_dev(sch)); + + if (opt) { + int err = codel_change(sch, opt, extack); + + if (err) + return err; + } + + if (sch->limit >= 1) + sch->flags |= TCQ_F_CAN_BYPASS; + else + sch->flags &= ~TCQ_F_CAN_BYPASS; + + sch->flags |= TCQ_F_DEQUEUE_DROPS; + + return 0; +} + +static int codel_dump(struct Qdisc *sch, struct sk_buff *skb) +{ + struct codel_sched_data *q = qdisc_priv(sch); + codel_time_t ce_threshold; + struct nlattr *opts; + + opts = nla_nest_start_noflag(skb, TCA_OPTIONS); + if (opts == NULL) + goto nla_put_failure; + + if (nla_put_u32(skb, TCA_CODEL_TARGET, + codel_time_to_us(READ_ONCE(q->params.target))) || + nla_put_u32(skb, TCA_CODEL_LIMIT, + READ_ONCE(sch->limit)) || + nla_put_u32(skb, TCA_CODEL_INTERVAL, + codel_time_to_us(READ_ONCE(q->params.interval))) || + nla_put_u32(skb, TCA_CODEL_ECN, + READ_ONCE(q->params.ecn))) + goto nla_put_failure; + ce_threshold = READ_ONCE(q->params.ce_threshold); + if (ce_threshold != CODEL_DISABLED_THRESHOLD && + nla_put_u32(skb, TCA_CODEL_CE_THRESHOLD, + codel_time_to_us(ce_threshold))) + goto nla_put_failure; + return nla_nest_end(skb, opts); + +nla_put_failure: + nla_nest_cancel(skb, opts); + return -1; +} + +static int codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) +{ + const struct codel_sched_data *q = qdisc_priv(sch); + struct tc_codel_xstats st = { + .maxpacket = READ_ONCE(q->stats.maxpacket), + .count = READ_ONCE(q->vars.count), + .lastcount = READ_ONCE(q->vars.lastcount), + .drop_overlimit = READ_ONCE(q->drop_overlimit), + .ldelay = codel_time_to_us(READ_ONCE(q->vars.ldelay)), + .dropping = READ_ONCE(q->vars.dropping), + .ecn_mark = READ_ONCE(q->stats.ecn_mark), + .ce_mark = READ_ONCE(q->stats.ce_mark), + }; + + if (st.dropping) { + codel_tdiff_t delta = READ_ONCE(q->vars.drop_next) - codel_get_time(); + + if (delta >= 0) + st.drop_next = codel_time_to_us(delta); + else + st.drop_next = -codel_time_to_us(-delta); + } + + return gnet_stats_copy_app(d, &st, sizeof(st)); +} + +static void codel_reset(struct Qdisc *sch) +{ + struct codel_sched_data *q = qdisc_priv(sch); + + qdisc_reset_queue(sch); + codel_vars_init(&q->vars); +} + +static struct Qdisc_ops codel_qdisc_ops __read_mostly = { + .id = "codel", + .priv_size = sizeof(struct codel_sched_data), + + .enqueue = codel_qdisc_enqueue, + .dequeue = codel_qdisc_dequeue, + .peek = codel_peek, + .init = codel_init, + .reset = codel_reset, + .change = codel_change, + .dump = codel_dump, + .dump_stats = codel_dump_stats, + .owner = THIS_MODULE, +}; +MODULE_ALIAS_NET_SCH("codel"); + +static int __init codel_module_init(void) +{ + return register_qdisc(&codel_qdisc_ops); +} + +static void __exit codel_module_exit(void) +{ + unregister_qdisc(&codel_qdisc_ops); +} + +module_init(codel_module_init) +module_exit(codel_module_exit) + +MODULE_DESCRIPTION("Controlled Delay queue discipline"); +MODULE_AUTHOR("Dave Taht"); +MODULE_AUTHOR("Eric Dumazet"); +MODULE_LICENSE("Dual BSD/GPL"); |
