[linux-block.git] / net / sched / sch_etf.c

// SPDX-License-Identifier: GPL-2.0

/* net/sched/sch_etf.c  Earliest TxTime First queueing discipline.
 *
 * Authors:	Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
 *		Vinicius Costa Gomes <vinicius.gomes@intel.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/errqueue.h>
#include <linux/rbtree.h>
#include <linux/skbuff.h>
#include <linux/posix-timers.h>
#include <net/netlink.h>
#include <net/sch_generic.h>
#include <net/pkt_sched.h>
#include <net/sock.h>

#define DEADLINE_MODE_IS_ON(x) ((x)->flags & TC_ETF_DEADLINE_MODE_ON)
#define OFFLOAD_IS_ON(x) ((x)->flags & TC_ETF_OFFLOAD_ON)

struct etf_sched_data {
	bool offload;
	bool deadline_mode;
	int clockid;
	int queue;
	s32 delta; /* in ns */
	ktime_t last; /* The txtime of the last skb sent to the netdevice. */
	struct rb_root_cached head;
	struct qdisc_watchdog watchdog;
	ktime_t (*get_time)(void);
};

static const struct nla_policy etf_policy[TCA_ETF_MAX + 1] = {
	[TCA_ETF_PARMS]	= { .len = sizeof(struct tc_etf_qopt) },
};

static inline int validate_input_params(struct tc_etf_qopt *qopt,
					struct netlink_ext_ack *extack)
{
	/* Check if params comply to the following rules:
	 *	* Clockid and delta must be valid.
	 *
	 *	* Dynamic clockids are not supported.
	 *
	 *	* Delta must be a positive integer.
	 *
	 * Also note that for the HW offload case, we must
	 * expect that system clocks have been synchronized to PHC.
	 */
	if (qopt->clockid < 0) {
		NL_SET_ERR_MSG(extack, "Dynamic clockids are not supported");
		return -ENOTSUPP;
	}

	if (qopt->clockid != CLOCK_TAI) {
		NL_SET_ERR_MSG(extack, "Invalid clockid. CLOCK_TAI must be used");
		return -EINVAL;
	}

	if (qopt->delta < 0) {
		NL_SET_ERR_MSG(extack, "Delta must be positive");
		return -EINVAL;
	}

	return 0;
}

static bool is_packet_valid(struct Qdisc *sch, struct sk_buff *nskb)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	ktime_t txtime = nskb->tstamp;
	struct sock *sk = nskb->sk;
	ktime_t now;

	if (!sk)
		return false;

	if (!sock_flag(sk, SOCK_TXTIME))
		return false;

	/* We don't perform crosstimestamping.
	 * Drop if packet's clockid differs from qdisc's.
	 */
	if (sk->sk_clockid != q->clockid)
		return false;

	if (sk->sk_txtime_deadline_mode != q->deadline_mode)
		return false;

	now = q->get_time();
	if (ktime_before(txtime, now) || ktime_before(txtime, q->last))
		return false;

	return true;
}

static struct sk_buff *etf_peek_timesortedlist(struct Qdisc *sch)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct rb_node *p;

	p = rb_first_cached(&q->head);
	if (!p)
		return NULL;

	return rb_to_skb(p);
}

static void reset_watchdog(struct Qdisc *sch)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb = etf_peek_timesortedlist(sch);
	ktime_t next;

	if (!skb) {
		qdisc_watchdog_cancel(&q->watchdog);
		return;
	}

	next = ktime_sub_ns(skb->tstamp, q->delta);
	qdisc_watchdog_schedule_ns(&q->watchdog, ktime_to_ns(next));
}

static void report_sock_error(struct sk_buff *skb, u32 err, u8 code)
{
	struct sock_exterr_skb *serr;
	struct sk_buff *clone;
	ktime_t txtime = skb->tstamp;

	if (!skb->sk || !(skb->sk->sk_txtime_report_errors))
		return;

	clone = skb_clone(skb, GFP_ATOMIC);
	if (!clone)
		return;

	serr = SKB_EXT_ERR(clone);
	serr->ee.ee_errno = err;
	serr->ee.ee_origin = SO_EE_ORIGIN_TXTIME;
	serr->ee.ee_type = 0;
	serr->ee.ee_code = code;
	serr->ee.ee_pad = 0;
	serr->ee.ee_data = (txtime >> 32); /* high part of tstamp */
	serr->ee.ee_info = txtime; /* low part of tstamp */

	if (sock_queue_err_skb(skb->sk, clone))
		kfree_skb(clone);
}

static int etf_enqueue_timesortedlist(struct sk_buff *nskb, struct Qdisc *sch,
				      struct sk_buff **to_free)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct rb_node **p = &q->head.rb_root.rb_node, *parent = NULL;
	ktime_t txtime = nskb->tstamp;
	bool leftmost = true;

	if (!is_packet_valid(sch, nskb)) {
		report_sock_error(nskb, EINVAL,
				  SO_EE_CODE_TXTIME_INVALID_PARAM);
		return qdisc_drop(nskb, sch, to_free);
	}

	while (*p) {
		struct sk_buff *skb;

		parent = *p;
		skb = rb_to_skb(parent);
		if (ktime_after(txtime, skb->tstamp)) {
			p = &parent->rb_right;
			leftmost = false;
		} else {
			p = &parent->rb_left;
		}
	}
	rb_link_node(&nskb->rbnode, parent, p);
	rb_insert_color_cached(&nskb->rbnode, &q->head, leftmost);

	qdisc_qstats_backlog_inc(sch, nskb);
	sch->q.qlen++;

	/* Now we may need to re-arm the qdisc watchdog for the next packet. */
	reset_watchdog(sch);

	return NET_XMIT_SUCCESS;
}

static void timesortedlist_erase(struct Qdisc *sch, struct sk_buff *skb,
				 bool drop)
{
	struct etf_sched_data *q = qdisc_priv(sch);

	rb_erase_cached(&skb->rbnode, &q->head);

	/* The rbnode field in the skb re-uses these fields, now that
	 * we are done with the rbnode, reset them.
	 */
	skb->next = NULL;
	skb->prev = NULL;
	skb->dev = qdisc_dev(sch);

	qdisc_qstats_backlog_dec(sch, skb);

	if (drop) {
		struct sk_buff *to_free = NULL;

		report_sock_error(skb, ECANCELED, SO_EE_CODE_TXTIME_MISSED);

		qdisc_drop(skb, sch, &to_free);
		kfree_skb_list(to_free);
		qdisc_qstats_overlimit(sch);
	} else {
		qdisc_bstats_update(sch, skb);

		q->last = skb->tstamp;
	}

	sch->q.qlen--;
}

static struct sk_buff *etf_dequeue_timesortedlist(struct Qdisc *sch)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;
	ktime_t now, next;

	skb = etf_peek_timesortedlist(sch);
	if (!skb)
		return NULL;

	now = q->get_time();

	/* Drop if packet has expired while in queue. */
	if (ktime_before(skb->tstamp, now)) {
		timesortedlist_erase(sch, skb, true);
		skb = NULL;
		goto out;
	}

	/* When in deadline mode, dequeue as soon as possible and change the
	 * txtime from deadline to (now + delta).
	 */
	if (q->deadline_mode) {
		timesortedlist_erase(sch, skb, false);
		skb->tstamp = now;
		goto out;
	}

	next = ktime_sub_ns(skb->tstamp, q->delta);

	/* Dequeue only if now is within the [txtime - delta, txtime] range. */
	if (ktime_after(now, next))
		timesortedlist_erase(sch, skb, false);
	else
		skb = NULL;

out:
	/* Now we may need to re-arm the qdisc watchdog for the next packet. */
	reset_watchdog(sch);

	return skb;
}

static void etf_disable_offload(struct net_device *dev,
				struct etf_sched_data *q)
{
	struct tc_etf_qopt_offload etf = { };
	const struct net_device_ops *ops;
	int err;

	if (!q->offload)
		return;

	ops = dev->netdev_ops;
	if (!ops->ndo_setup_tc)
		return;

	etf.queue = q->queue;
	etf.enable = 0;

	err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_ETF, &etf);
	if (err < 0)
		pr_warn("Couldn't disable ETF offload for queue %d\n",
			etf.queue);
}

static int etf_enable_offload(struct net_device *dev, struct etf_sched_data *q,
			      struct netlink_ext_ack *extack)
{
	const struct net_device_ops *ops = dev->netdev_ops;
	struct tc_etf_qopt_offload etf = { };
	int err;

	if (q->offload)
		return 0;

	if (!ops->ndo_setup_tc) {
		NL_SET_ERR_MSG(extack, "Specified device does not support ETF offload");
		return -EOPNOTSUPP;
	}

	etf.queue = q->queue;
	etf.enable = 1;

	err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_ETF, &etf);
	if (err < 0) {
		NL_SET_ERR_MSG(extack, "Specified device failed to setup ETF hardware offload");
		return err;
	}

	return 0;
}

static int etf_init(struct Qdisc *sch, struct nlattr *opt,
		    struct netlink_ext_ack *extack)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct net_device *dev = qdisc_dev(sch);
	struct nlattr *tb[TCA_ETF_MAX + 1];
	struct tc_etf_qopt *qopt;
	int err;

	if (!opt) {
		NL_SET_ERR_MSG(extack,
			       "Missing ETF qdisc options which are mandatory");
		return -EINVAL;
	}

	err = nla_parse_nested(tb, TCA_ETF_MAX, opt, etf_policy, extack);
	if (err < 0)
		return err;

	if (!tb[TCA_ETF_PARMS]) {
		NL_SET_ERR_MSG(extack, "Missing mandatory ETF parameters");
		return -EINVAL;
	}

	qopt = nla_data(tb[TCA_ETF_PARMS]);

	pr_debug("delta %d clockid %d offload %s deadline %s\n",
		 qopt->delta, qopt->clockid,
		 OFFLOAD_IS_ON(qopt) ? "on" : "off",
		 DEADLINE_MODE_IS_ON(qopt) ? "on" : "off");

	err = validate_input_params(qopt, extack);
	if (err < 0)
		return err;

	q->queue = sch->dev_queue - netdev_get_tx_queue(dev, 0);

	if (OFFLOAD_IS_ON(qopt)) {
		err = etf_enable_offload(dev, q, extack);
		if (err < 0)
			return err;
	}

	/* Everything went OK, save the parameters used. */
	q->delta = qopt->delta;
	q->clockid = qopt->clockid;
	q->offload = OFFLOAD_IS_ON(qopt);
	q->deadline_mode = DEADLINE_MODE_IS_ON(qopt);

	switch (q->clockid) {
	case CLOCK_REALTIME:
		q->get_time = ktime_get_real;
		break;
	case CLOCK_MONOTONIC:
		q->get_time = ktime_get;
		break;
	case CLOCK_BOOTTIME:
		q->get_time = ktime_get_boottime;
		break;
	case CLOCK_TAI:
		q->get_time = ktime_get_clocktai;
		break;
	default:
		NL_SET_ERR_MSG(extack, "Clockid is not supported");
		return -ENOTSUPP;
	}

	qdisc_watchdog_init_clockid(&q->watchdog, sch, q->clockid);

	return 0;
}

static void timesortedlist_clear(struct Qdisc *sch)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct rb_node *p = rb_first_cached(&q->head);

	while (p) {
		struct sk_buff *skb = rb_to_skb(p);

		p = rb_next(p);

		rb_erase_cached(&skb->rbnode, &q->head);
		rtnl_kfree_skbs(skb, skb);
		sch->q.qlen--;
	}
}

static void etf_reset(struct Qdisc *sch)
{
	struct etf_sched_data *q = qdisc_priv(sch);

	/* Only cancel watchdog if it's been initialized. */
	if (q->watchdog.qdisc == sch)
		qdisc_watchdog_cancel(&q->watchdog);

	/* No matter which mode we are on, it's safe to clear both lists. */
	timesortedlist_clear(sch);
	__qdisc_reset_queue(&sch->q);

	sch->qstats.backlog = 0;
	sch->q.qlen = 0;

	q->last = 0;
}

static void etf_destroy(struct Qdisc *sch)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct net_device *dev = qdisc_dev(sch);

	/* Only cancel watchdog if it's been initialized. */
	if (q->watchdog.qdisc == sch)
		qdisc_watchdog_cancel(&q->watchdog);

	etf_disable_offload(dev, q);
}

static int etf_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct etf_sched_data *q = qdisc_priv(sch);
	struct tc_etf_qopt opt = { };
	struct nlattr *nest;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (!nest)
		goto nla_put_failure;

	opt.delta = q->delta;
	opt.clockid = q->clockid;
	if (q->offload)
		opt.flags |= TC_ETF_OFFLOAD_ON;

	if (q->deadline_mode)
		opt.flags |= TC_ETF_DEADLINE_MODE_ON;

	if (nla_put(skb, TCA_ETF_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;

	return nla_nest_end(skb, nest);

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

static struct Qdisc_ops etf_qdisc_ops __read_mostly = {
	.id		=	"etf",
	.priv_size	=	sizeof(struct etf_sched_data),
	.enqueue	=	etf_enqueue_timesortedlist,
	.dequeue	=	etf_dequeue_timesortedlist,
	.peek		=	etf_peek_timesortedlist,
	.init		=	etf_init,
	.reset		=	etf_reset,
	.destroy	=	etf_destroy,
	.dump		=	etf_dump,
	.owner		=	THIS_MODULE,
};

static int __init etf_module_init(void)
{
	return register_qdisc(&etf_qdisc_ops);
}

static void __exit etf_module_exit(void)
{
	unregister_qdisc(&etf_qdisc_ops);
}
module_init(etf_module_init)
module_exit(etf_module_exit)
MODULE_LICENSE("GPL");
Commit	Line	Data
25db26a9 VCG	1	// SPDX-License-Identifier: GPL-2.0
	2
	3	/* net/sched/sch_etf.c Earliest TxTime First queueing discipline.
	4	*
	5	* Authors: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
	6	* Vinicius Costa Gomes <vinicius.gomes@intel.com>
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/types.h>
	11	#include <linux/kernel.h>
	12	#include <linux/string.h>
	13	#include <linux/errno.h>
4b15c707	14	#include <linux/errqueue.h>
25db26a9 VCG	15	#include <linux/rbtree.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/posix-timers.h>
	18	#include <net/netlink.h>
	19	#include <net/sch_generic.h>
	20	#include <net/pkt_sched.h>
	21	#include <net/sock.h>
	22
	23	#define DEADLINE_MODE_IS_ON(x) ((x)->flags & TC_ETF_DEADLINE_MODE_ON)
88cab771	24	#define OFFLOAD_IS_ON(x) ((x)->flags & TC_ETF_OFFLOAD_ON)
25db26a9 VCG	25
25db26a9 VCG	26	struct etf_sched_data {
88cab771	27	bool offload;
25db26a9 VCG	28	bool deadline_mode;
	29	int clockid;
	30	int queue;
	31	s32 delta; /* in ns */
	32	ktime_t last; /* The txtime of the last skb sent to the netdevice. */
09fd4860	33	struct rb_root_cached head;
25db26a9 VCG	34	struct qdisc_watchdog watchdog;
	35	ktime_t (*get_time)(void);
	36	};
	37
	38	static const struct nla_policy etf_policy[TCA_ETF_MAX + 1] = {
	39	[TCA_ETF_PARMS] = { .len = sizeof(struct tc_etf_qopt) },
	40	};
	41
	42	static inline int validate_input_params(struct tc_etf_qopt *qopt,
	43	struct netlink_ext_ack *extack)
	44	{
	45	/* Check if params comply to the following rules:
	46	* * Clockid and delta must be valid.
	47	*
	48	* * Dynamic clockids are not supported.
	49	*
	50	* * Delta must be a positive integer.
88cab771 JSP	51	*
	52	* Also note that for the HW offload case, we must
	53	* expect that system clocks have been synchronized to PHC.
25db26a9 VCG	54	*/
	55	if (qopt->clockid < 0) {
	56	NL_SET_ERR_MSG(extack, "Dynamic clockids are not supported");
	57	return -ENOTSUPP;
	58	}
	59
	60	if (qopt->clockid != CLOCK_TAI) {
	61	NL_SET_ERR_MSG(extack, "Invalid clockid. CLOCK_TAI must be used");
	62	return -EINVAL;
	63	}
	64
	65	if (qopt->delta < 0) {
	66	NL_SET_ERR_MSG(extack, "Delta must be positive");
	67	return -EINVAL;
	68	}
	69
	70	return 0;
	71	}
	72
	73	static bool is_packet_valid(struct Qdisc sch, struct sk_buff nskb)
	74	{
	75	struct etf_sched_data *q = qdisc_priv(sch);
	76	ktime_t txtime = nskb->tstamp;
	77	struct sock *sk = nskb->sk;
	78	ktime_t now;
	79
	80	if (!sk)
	81	return false;
	82
	83	if (!sock_flag(sk, SOCK_TXTIME))
	84	return false;
	85
	86	/* We don't perform crosstimestamping.
	87	* Drop if packet's clockid differs from qdisc's.
	88	*/
	89	if (sk->sk_clockid != q->clockid)
	90	return false;
	91
	92	if (sk->sk_txtime_deadline_mode != q->deadline_mode)
	93	return false;
	94
	95	now = q->get_time();
	96	if (ktime_before(txtime, now) \|\| ktime_before(txtime, q->last))
	97	return false;
	98
	99	return true;
	100	}
	101
	102	static struct sk_buff etf_peek_timesortedlist(struct Qdisc sch)
	103	{
	104	struct etf_sched_data *q = qdisc_priv(sch);
	105	struct rb_node *p;
	106
09fd4860	107	p = rb_first_cached(&q->head);
25db26a9 VCG	108	if (!p)
	109	return NULL;
	110
	111	return rb_to_skb(p);
	112	}
	113
	114	static void reset_watchdog(struct Qdisc *sch)
	115	{
	116	struct etf_sched_data *q = qdisc_priv(sch);
	117	struct sk_buff *skb = etf_peek_timesortedlist(sch);
	118	ktime_t next;
	119
3fcbdaee JSP	120	if (!skb) {
3fcbdaee JSP	121	qdisc_watchdog_cancel(&q->watchdog);
25db26a9	122	return;
3fcbdaee	123	}
25db26a9 VCG	124
	125	next = ktime_sub_ns(skb->tstamp, q->delta);
	126	qdisc_watchdog_schedule_ns(&q->watchdog, ktime_to_ns(next));
	127	}
	128
4b15c707 JSP	129	static void report_sock_error(struct sk_buff *skb, u32 err, u8 code)
	130	{
	131	struct sock_exterr_skb *serr;
	132	struct sk_buff *clone;
	133	ktime_t txtime = skb->tstamp;
	134
	135	if (!skb->sk \|\| !(skb->sk->sk_txtime_report_errors))
	136	return;
	137
	138	clone = skb_clone(skb, GFP_ATOMIC);
	139	if (!clone)
	140	return;
	141
	142	serr = SKB_EXT_ERR(clone);
	143	serr->ee.ee_errno = err;
	144	serr->ee.ee_origin = SO_EE_ORIGIN_TXTIME;
	145	serr->ee.ee_type = 0;
	146	serr->ee.ee_code = code;
	147	serr->ee.ee_pad = 0;
	148	serr->ee.ee_data = (txtime >> 32); /* high part of tstamp */
	149	serr->ee.ee_info = txtime; /* low part of tstamp */
	150
	151	if (sock_queue_err_skb(skb->sk, clone))
	152	kfree_skb(clone);
	153	}
	154
25db26a9 VCG	155	static int etf_enqueue_timesortedlist(struct sk_buff nskb, struct Qdisc sch,
	156	struct sk_buff **to_free)
	157	{
	158	struct etf_sched_data *q = qdisc_priv(sch);
09fd4860	159	struct rb_node *p = &q->head.rb_root.rb_node, parent = NULL;
25db26a9	160	ktime_t txtime = nskb->tstamp;
09fd4860	161	bool leftmost = true;
25db26a9	162
4b15c707 JSP	163	if (!is_packet_valid(sch, nskb)) {
	164	report_sock_error(nskb, EINVAL,
	165	SO_EE_CODE_TXTIME_INVALID_PARAM);
25db26a9	166	return qdisc_drop(nskb, sch, to_free);
4b15c707	167	}
25db26a9 VCG	168
	169	while (*p) {
	170	struct sk_buff *skb;
	171
	172	parent = *p;
	173	skb = rb_to_skb(parent);
09fd4860	174	if (ktime_after(txtime, skb->tstamp)) {
25db26a9	175	p = &parent->rb_right;
09fd4860 JSP	176	leftmost = false;
09fd4860 JSP	177	} else {
25db26a9	178	p = &parent->rb_left;
09fd4860	179	}
25db26a9 VCG	180	}
25db26a9 VCG	181	rb_link_node(&nskb->rbnode, parent, p);
09fd4860	182	rb_insert_color_cached(&nskb->rbnode, &q->head, leftmost);
25db26a9 VCG	183
	184	qdisc_qstats_backlog_inc(sch, nskb);
	185	sch->q.qlen++;
	186
	187	/* Now we may need to re-arm the qdisc watchdog for the next packet. */
	188	reset_watchdog(sch);
	189
	190	return NET_XMIT_SUCCESS;
	191	}
	192
	193	static void timesortedlist_erase(struct Qdisc sch, struct sk_buff skb,
	194	bool drop)
	195	{
	196	struct etf_sched_data *q = qdisc_priv(sch);
	197
09fd4860	198	rb_erase_cached(&skb->rbnode, &q->head);
25db26a9 VCG	199
	200	/* The rbnode field in the skb re-uses these fields, now that
	201	* we are done with the rbnode, reset them.
	202	*/
	203	skb->next = NULL;
	204	skb->prev = NULL;
	205	skb->dev = qdisc_dev(sch);
	206
	207	qdisc_qstats_backlog_dec(sch, skb);
	208
	209	if (drop) {
	210	struct sk_buff *to_free = NULL;
	211
4b15c707 JSP	212	report_sock_error(skb, ECANCELED, SO_EE_CODE_TXTIME_MISSED);
4b15c707 JSP	213
25db26a9 VCG	214	qdisc_drop(skb, sch, &to_free);
	215	kfree_skb_list(to_free);
	216	qdisc_qstats_overlimit(sch);
	217	} else {
	218	qdisc_bstats_update(sch, skb);
	219
	220	q->last = skb->tstamp;
	221	}
	222
	223	sch->q.qlen--;
	224	}
	225
	226	static struct sk_buff etf_dequeue_timesortedlist(struct Qdisc sch)
	227	{
	228	struct etf_sched_data *q = qdisc_priv(sch);
	229	struct sk_buff *skb;
	230	ktime_t now, next;
	231
	232	skb = etf_peek_timesortedlist(sch);
	233	if (!skb)
	234	return NULL;
	235
	236	now = q->get_time();
	237
	238	/* Drop if packet has expired while in queue. */
25db26a9 VCG	239	if (ktime_before(skb->tstamp, now)) {
	240	timesortedlist_erase(sch, skb, true);
	241	skb = NULL;
	242	goto out;
	243	}
	244
	245	/* When in deadline mode, dequeue as soon as possible and change the
	246	* txtime from deadline to (now + delta).
	247	*/
	248	if (q->deadline_mode) {
	249	timesortedlist_erase(sch, skb, false);
	250	skb->tstamp = now;
	251	goto out;
	252	}
	253
	254	next = ktime_sub_ns(skb->tstamp, q->delta);
	255
	256	/* Dequeue only if now is within the [txtime - delta, txtime] range. */
	257	if (ktime_after(now, next))
	258	timesortedlist_erase(sch, skb, false);
	259	else
	260	skb = NULL;
	261
	262	out:
	263	/* Now we may need to re-arm the qdisc watchdog for the next packet. */
	264	reset_watchdog(sch);
	265
	266	return skb;
	267	}
	268
88cab771 JSP	269	static void etf_disable_offload(struct net_device *dev,
	270	struct etf_sched_data *q)
	271	{
	272	struct tc_etf_qopt_offload etf = { };
	273	const struct net_device_ops *ops;
	274	int err;
	275
	276	if (!q->offload)
	277	return;
	278
	279	ops = dev->netdev_ops;
	280	if (!ops->ndo_setup_tc)
	281	return;
	282
	283	etf.queue = q->queue;
	284	etf.enable = 0;
	285
	286	err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_ETF, &etf);
	287	if (err < 0)
	288	pr_warn("Couldn't disable ETF offload for queue %d\n",
	289	etf.queue);
	290	}
	291
	292	static int etf_enable_offload(struct net_device dev, struct etf_sched_data q,
	293	struct netlink_ext_ack *extack)
	294	{
	295	const struct net_device_ops *ops = dev->netdev_ops;
	296	struct tc_etf_qopt_offload etf = { };
	297	int err;
	298
	299	if (q->offload)
	300	return 0;
	301
	302	if (!ops->ndo_setup_tc) {
	303	NL_SET_ERR_MSG(extack, "Specified device does not support ETF offload");
	304	return -EOPNOTSUPP;
	305	}
	306
	307	etf.queue = q->queue;
	308	etf.enable = 1;
	309
	310	err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_ETF, &etf);
	311	if (err < 0) {
	312	NL_SET_ERR_MSG(extack, "Specified device failed to setup ETF hardware offload");
	313	return err;
	314	}
	315
	316	return 0;
	317	}
	318
25db26a9 VCG	319	static int etf_init(struct Qdisc sch, struct nlattr opt,
	320	struct netlink_ext_ack *extack)
	321	{
	322	struct etf_sched_data *q = qdisc_priv(sch);
	323	struct net_device *dev = qdisc_dev(sch);
	324	struct nlattr *tb[TCA_ETF_MAX + 1];
	325	struct tc_etf_qopt *qopt;
	326	int err;
	327
	328	if (!opt) {
	329	NL_SET_ERR_MSG(extack,
	330	"Missing ETF qdisc options which are mandatory");
	331	return -EINVAL;
	332	}
	333
	334	err = nla_parse_nested(tb, TCA_ETF_MAX, opt, etf_policy, extack);
	335	if (err < 0)
	336	return err;
	337
	338	if (!tb[TCA_ETF_PARMS]) {
	339	NL_SET_ERR_MSG(extack, "Missing mandatory ETF parameters");
	340	return -EINVAL;
	341	}
	342
	343	qopt = nla_data(tb[TCA_ETF_PARMS]);
	344
88cab771	345	pr_debug("delta %d clockid %d offload %s deadline %s\n",
25db26a9	346	qopt->delta, qopt->clockid,
88cab771	347	OFFLOAD_IS_ON(qopt) ? "on" : "off",
25db26a9 VCG	348	DEADLINE_MODE_IS_ON(qopt) ? "on" : "off");
	349
	350	err = validate_input_params(qopt, extack);
	351	if (err < 0)
	352	return err;
	353
	354	q->queue = sch->dev_queue - netdev_get_tx_queue(dev, 0);
	355
88cab771 JSP	356	if (OFFLOAD_IS_ON(qopt)) {
	357	err = etf_enable_offload(dev, q, extack);
	358	if (err < 0)
	359	return err;
	360	}
	361
25db26a9 VCG	362	/* Everything went OK, save the parameters used. */
	363	q->delta = qopt->delta;
	364	q->clockid = qopt->clockid;
88cab771	365	q->offload = OFFLOAD_IS_ON(qopt);
25db26a9 VCG	366	q->deadline_mode = DEADLINE_MODE_IS_ON(qopt);
	367
	368	switch (q->clockid) {
	369	case CLOCK_REALTIME:
	370	q->get_time = ktime_get_real;
	371	break;
	372	case CLOCK_MONOTONIC:
	373	q->get_time = ktime_get;
	374	break;
	375	case CLOCK_BOOTTIME:
	376	q->get_time = ktime_get_boottime;
	377	break;
	378	case CLOCK_TAI:
	379	q->get_time = ktime_get_clocktai;
	380	break;
	381	default:
	382	NL_SET_ERR_MSG(extack, "Clockid is not supported");
	383	return -ENOTSUPP;
	384	}
	385
	386	qdisc_watchdog_init_clockid(&q->watchdog, sch, q->clockid);
	387
	388	return 0;
	389	}
	390
	391	static void timesortedlist_clear(struct Qdisc *sch)
	392	{
	393	struct etf_sched_data *q = qdisc_priv(sch);
09fd4860	394	struct rb_node *p = rb_first_cached(&q->head);
25db26a9 VCG	395
	396	while (p) {
	397	struct sk_buff *skb = rb_to_skb(p);
	398
	399	p = rb_next(p);
	400
09fd4860	401	rb_erase_cached(&skb->rbnode, &q->head);
25db26a9 VCG	402	rtnl_kfree_skbs(skb, skb);
	403	sch->q.qlen--;
	404	}
	405	}
	406
	407	static void etf_reset(struct Qdisc *sch)
	408	{
	409	struct etf_sched_data *q = qdisc_priv(sch);
	410
	411	/* Only cancel watchdog if it's been initialized. */
	412	if (q->watchdog.qdisc == sch)
	413	qdisc_watchdog_cancel(&q->watchdog);
	414
	415	/* No matter which mode we are on, it's safe to clear both lists. */
	416	timesortedlist_clear(sch);
	417	__qdisc_reset_queue(&sch->q);
	418
	419	sch->qstats.backlog = 0;
	420	sch->q.qlen = 0;
	421
	422	q->last = 0;
	423	}
	424
	425	static void etf_destroy(struct Qdisc *sch)
	426	{
	427	struct etf_sched_data *q = qdisc_priv(sch);
88cab771	428	struct net_device *dev = qdisc_dev(sch);
25db26a9 VCG	429
	430	/* Only cancel watchdog if it's been initialized. */
	431	if (q->watchdog.qdisc == sch)
	432	qdisc_watchdog_cancel(&q->watchdog);
88cab771 JSP	433
88cab771 JSP	434	etf_disable_offload(dev, q);
25db26a9 VCG	435	}
	436
	437	static int etf_dump(struct Qdisc sch, struct sk_buff skb)
	438	{
	439	struct etf_sched_data *q = qdisc_priv(sch);
	440	struct tc_etf_qopt opt = { };
	441	struct nlattr *nest;
	442
	443	nest = nla_nest_start(skb, TCA_OPTIONS);
	444	if (!nest)
	445	goto nla_put_failure;
	446
	447	opt.delta = q->delta;
	448	opt.clockid = q->clockid;
88cab771 JSP	449	if (q->offload)
	450	opt.flags \|= TC_ETF_OFFLOAD_ON;
	451
25db26a9 VCG	452	if (q->deadline_mode)
	453	opt.flags \|= TC_ETF_DEADLINE_MODE_ON;
	454
	455	if (nla_put(skb, TCA_ETF_PARMS, sizeof(opt), &opt))
	456	goto nla_put_failure;
	457
	458	return nla_nest_end(skb, nest);
	459
	460	nla_put_failure:
	461	nla_nest_cancel(skb, nest);
	462	return -1;
	463	}
	464
	465	static struct Qdisc_ops etf_qdisc_ops __read_mostly = {
	466	.id = "etf",
	467	.priv_size = sizeof(struct etf_sched_data),
	468	.enqueue = etf_enqueue_timesortedlist,
	469	.dequeue = etf_dequeue_timesortedlist,
	470	.peek = etf_peek_timesortedlist,
	471	.init = etf_init,
	472	.reset = etf_reset,
	473	.destroy = etf_destroy,
	474	.dump = etf_dump,
	475	.owner = THIS_MODULE,
	476	};
	477
	478	static int __init etf_module_init(void)
	479	{
	480	return register_qdisc(&etf_qdisc_ops);
	481	}
	482
	483	static void __exit etf_module_exit(void)
	484	{
	485	unregister_qdisc(&etf_qdisc_ops);
	486	}
	487	module_init(etf_module_init)
	488	module_exit(etf_module_exit)
	489	MODULE_LICENSE("GPL");