[linux-block.git] / net / sctp / stream_sched.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* SCTP kernel implementation
 * (C) Copyright Red Hat Inc. 2017
 *
 * This file is part of the SCTP kernel implementation
 *
 * These functions manipulate sctp stream queue/scheduling.
 *
 * Please send any bug reports or fixes you make to the
 * email addresched(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
 */

#include <linux/list.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <net/sctp/stream_sched.h>

/* First Come First Serve (a.k.a. FIFO)
 * RFC DRAFT ndata Section 3.1
 */
static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
			       __u16 value, gfp_t gfp)
{
	return 0;
}

static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
			       __u16 *value)
{
	*value = 0;
	return 0;
}

static int sctp_sched_fcfs_init(struct sctp_stream *stream)
{
	return 0;
}

static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
				    gfp_t gfp)
{
	return 0;
}

static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid)
{
}

static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
				    struct sctp_datamsg *msg)
{
}

static struct sctp_chunk *sctp_sched_fcfs_dequeue(struct sctp_outq *q)
{
	struct sctp_stream *stream = &q->asoc->stream;
	struct sctp_chunk *ch = NULL;
	struct list_head *entry;

	if (list_empty(&q->out_chunk_list))
		goto out;

	if (stream->out_curr) {
		ch = list_entry(stream->out_curr->ext->outq.next,
				struct sctp_chunk, stream_list);
	} else {
		entry = q->out_chunk_list.next;
		ch = list_entry(entry, struct sctp_chunk, list);
	}

	sctp_sched_dequeue_common(q, ch);

out:
	return ch;
}

static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
					 struct sctp_chunk *chunk)
{
}

static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
{
}

static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
{
}

static struct sctp_sched_ops sctp_sched_fcfs = {
	.set = sctp_sched_fcfs_set,
	.get = sctp_sched_fcfs_get,
	.init = sctp_sched_fcfs_init,
	.init_sid = sctp_sched_fcfs_init_sid,
	.free_sid = sctp_sched_fcfs_free_sid,
	.enqueue = sctp_sched_fcfs_enqueue,
	.dequeue = sctp_sched_fcfs_dequeue,
	.dequeue_done = sctp_sched_fcfs_dequeue_done,
	.sched_all = sctp_sched_fcfs_sched_all,
	.unsched_all = sctp_sched_fcfs_unsched_all,
};

static void sctp_sched_ops_fcfs_init(void)
{
	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
}

/* API to other parts of the stack */

static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];

void sctp_sched_ops_register(enum sctp_sched_type sched,
			     struct sctp_sched_ops *sched_ops)
{
	sctp_sched_ops[sched] = sched_ops;
}

void sctp_sched_ops_init(void)
{
	sctp_sched_ops_fcfs_init();
	sctp_sched_ops_prio_init();
	sctp_sched_ops_rr_init();
}

static void sctp_sched_free_sched(struct sctp_stream *stream)
{
	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
	struct sctp_stream_out_ext *soute;
	int i;

	sched->unsched_all(stream);
	for (i = 0; i < stream->outcnt; i++) {
		soute = SCTP_SO(stream, i)->ext;
		if (!soute)
			continue;
		sched->free_sid(stream, i);
		/* Give the next scheduler a clean slate. */
		memset_after(soute, 0, outq);
	}
}

int sctp_sched_set_sched(struct sctp_association *asoc,
			 enum sctp_sched_type sched)
{
	struct sctp_sched_ops *n = sctp_sched_ops[sched];
	struct sctp_sched_ops *old = asoc->outqueue.sched;
	struct sctp_datamsg *msg = NULL;
	struct sctp_chunk *ch;
	int i, ret = 0;

	if (old == n)
		return ret;

	if (sched > SCTP_SS_MAX)
		return -EINVAL;

	if (old)
		sctp_sched_free_sched(&asoc->stream);

	asoc->outqueue.sched = n;
	n->init(&asoc->stream);
	for (i = 0; i < asoc->stream.outcnt; i++) {
		if (!SCTP_SO(&asoc->stream, i)->ext)
			continue;

		ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC);
		if (ret)
			goto err;
	}

	/* We have to requeue all chunks already queued. */
	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
		if (ch->msg == msg)
			continue;
		msg = ch->msg;
		n->enqueue(&asoc->outqueue, msg);
	}

	return ret;

err:
	sctp_sched_free_sched(&asoc->stream);
	asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */

	return ret;
}

int sctp_sched_get_sched(struct sctp_association *asoc)
{
	int i;

	for (i = 0; i <= SCTP_SS_MAX; i++)
		if (asoc->outqueue.sched == sctp_sched_ops[i])
			return i;

	return 0;
}

int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
			 __u16 value, gfp_t gfp)
{
	if (sid >= asoc->stream.outcnt)
		return -EINVAL;

	if (!SCTP_SO(&asoc->stream, sid)->ext) {
		int ret;

		ret = sctp_stream_init_ext(&asoc->stream, sid);
		if (ret)
			return ret;
	}

	return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
}

int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
			 __u16 *value)
{
	if (sid >= asoc->stream.outcnt)
		return -EINVAL;

	if (!SCTP_SO(&asoc->stream, sid)->ext)
		return 0;

	return asoc->outqueue.sched->get(&asoc->stream, sid, value);
}

void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch)
{
	if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
	    !q->asoc->peer.intl_capable) {
		struct sctp_stream_out *sout;
		__u16 sid;

		/* datamsg is not finish, so save it as current one,
		 * in case application switch scheduler or a higher
		 * priority stream comes in.
		 */
		sid = sctp_chunk_stream_no(ch);
		sout = SCTP_SO(&q->asoc->stream, sid);
		q->asoc->stream.out_curr = sout;
		return;
	}

	q->asoc->stream.out_curr = NULL;
	q->sched->dequeue_done(q, ch);
}

/* Auxiliary functions for the schedulers */
void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch)
{
	list_del_init(&ch->list);
	list_del_init(&ch->stream_list);
	q->out_qlen -= ch->skb->len;
}

int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
{
	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
	struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;

	INIT_LIST_HEAD(&ext->outq);
	return sched->init_sid(stream, sid, gfp);
}

struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream)
{
	struct sctp_association *asoc;

	asoc = container_of(stream, struct sctp_association, stream);

	return asoc->outqueue.sched;
}
Commit	Line	Data
47505b8b	1	// SPDX-License-Identifier: GPL-2.0-or-later
5bbbbe32 MRL	2	/* SCTP kernel implementation
	3	* (C) Copyright Red Hat Inc. 2017
	4	*
	5	* This file is part of the SCTP kernel implementation
	6	*
	7	* These functions manipulate sctp stream queue/scheduling.
	8	*
5bbbbe32 MRL	9	* Please send any bug reports or fixes you make to the
	10	* email addresched(es):
	11	* lksctp developers <linux-sctp@vger.kernel.org>
	12	*
	13	* Written or modified by:
	14	* Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
	15	*/
	16
	17	#include <linux/list.h>
	18	#include <net/sctp/sctp.h>
	19	#include <net/sctp/sm.h>
	20	#include <net/sctp/stream_sched.h>
	21
	22	/* First Come First Serve (a.k.a. FIFO)
	23	* RFC DRAFT ndata Section 3.1
	24	*/
	25	static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
	26	__u16 value, gfp_t gfp)
	27	{
	28	return 0;
	29	}
	30
	31	static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
	32	__u16 *value)
	33	{
	34	*value = 0;
	35	return 0;
	36	}
	37
	38	static int sctp_sched_fcfs_init(struct sctp_stream *stream)
	39	{
	40	return 0;
	41	}
	42
	43	static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
	44	gfp_t gfp)
	45	{
	46	return 0;
	47	}
	48
9ed7bfc7 ZS	49	static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid)
	50	{
	51	}
	52
5bbbbe32 MRL	53	static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
	54	struct sctp_datamsg *msg)
	55	{
	56	}
	57
	58	static struct sctp_chunk sctp_sched_fcfs_dequeue(struct sctp_outq q)
	59	{
	60	struct sctp_stream *stream = &q->asoc->stream;
	61	struct sctp_chunk *ch = NULL;
	62	struct list_head *entry;
	63
	64	if (list_empty(&q->out_chunk_list))
	65	goto out;
	66
	67	if (stream->out_curr) {
	68	ch = list_entry(stream->out_curr->ext->outq.next,
	69	struct sctp_chunk, stream_list);
	70	} else {
	71	entry = q->out_chunk_list.next;
	72	ch = list_entry(entry, struct sctp_chunk, list);
	73	}
	74
	75	sctp_sched_dequeue_common(q, ch);
	76
	77	out:
	78	return ch;
	79	}
	80
	81	static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
	82	struct sctp_chunk *chunk)
	83	{
	84	}
	85
	86	static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
	87	{
	88	}
	89
	90	static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
	91	{
	92	}
	93
	94	static struct sctp_sched_ops sctp_sched_fcfs = {
	95	.set = sctp_sched_fcfs_set,
	96	.get = sctp_sched_fcfs_get,
	97	.init = sctp_sched_fcfs_init,
	98	.init_sid = sctp_sched_fcfs_init_sid,
9ed7bfc7	99	.free_sid = sctp_sched_fcfs_free_sid,
5bbbbe32 MRL	100	.enqueue = sctp_sched_fcfs_enqueue,
	101	.dequeue = sctp_sched_fcfs_dequeue,
	102	.dequeue_done = sctp_sched_fcfs_dequeue_done,
	103	.sched_all = sctp_sched_fcfs_sched_all,
	104	.unsched_all = sctp_sched_fcfs_unsched_all,
	105	};
	106
1ba896f6 XL	107	static void sctp_sched_ops_fcfs_init(void)
	108	{
	109	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
	110	}
	111
5bbbbe32 MRL	112	/* API to other parts of the stack */
5bbbbe32 MRL	113
1ba896f6	114	static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];
637784ad	115
1ba896f6 XL	116	void sctp_sched_ops_register(enum sctp_sched_type sched,
	117	struct sctp_sched_ops *sched_ops)
	118	{
	119	sctp_sched_ops[sched] = sched_ops;
	120	}
	121
	122	void sctp_sched_ops_init(void)
	123	{
	124	sctp_sched_ops_fcfs_init();
	125	sctp_sched_ops_prio_init();
	126	sctp_sched_ops_rr_init();
	127	}
5bbbbe32	128
7d802c80 XL	129	static void sctp_sched_free_sched(struct sctp_stream *stream)
	130	{
	131	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
	132	struct sctp_stream_out_ext *soute;
	133	int i;
	134
	135	sched->unsched_all(stream);
	136	for (i = 0; i < stream->outcnt; i++) {
	137	soute = SCTP_SO(stream, i)->ext;
	138	if (!soute)
	139	continue;
	140	sched->free_sid(stream, i);
	141	/* Give the next scheduler a clean slate. */
	142	memset_after(soute, 0, outq);
	143	}
	144	}
	145
5bbbbe32 MRL	146	int sctp_sched_set_sched(struct sctp_association *asoc,
	147	enum sctp_sched_type sched)
	148	{
	149	struct sctp_sched_ops *n = sctp_sched_ops[sched];
	150	struct sctp_sched_ops *old = asoc->outqueue.sched;
	151	struct sctp_datamsg *msg = NULL;
	152	struct sctp_chunk *ch;
	153	int i, ret = 0;
	154
	155	if (old == n)
	156	return ret;
	157
	158	if (sched > SCTP_SS_MAX)
	159	return -EINVAL;
	160
7d802c80 XL	161	if (old)
7d802c80 XL	162	sctp_sched_free_sched(&asoc->stream);
5bbbbe32 MRL	163
	164	asoc->outqueue.sched = n;
	165	n->init(&asoc->stream);
	166	for (i = 0; i < asoc->stream.outcnt; i++) {
05364ca0	167	if (!SCTP_SO(&asoc->stream, i)->ext)
5bbbbe32 MRL	168	continue;
5bbbbe32 MRL	169
b89fc26f	170	ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC);
5bbbbe32 MRL	171	if (ret)
	172	goto err;
	173	}
	174
	175	/* We have to requeue all chunks already queued. */
	176	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
	177	if (ch->msg == msg)
	178	continue;
	179	msg = ch->msg;
	180	n->enqueue(&asoc->outqueue, msg);
	181	}
	182
	183	return ret;
	184
	185	err:
7d802c80	186	sctp_sched_free_sched(&asoc->stream);
5bbbbe32 MRL	187	asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */
	188
	189	return ret;
	190	}
	191
	192	int sctp_sched_get_sched(struct sctp_association *asoc)
	193	{
	194	int i;
	195
	196	for (i = 0; i <= SCTP_SS_MAX; i++)
	197	if (asoc->outqueue.sched == sctp_sched_ops[i])
	198	return i;
	199
	200	return 0;
	201	}
	202
	203	int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
	204	__u16 value, gfp_t gfp)
	205	{
	206	if (sid >= asoc->stream.outcnt)
	207	return -EINVAL;
	208
05364ca0	209	if (!SCTP_SO(&asoc->stream, sid)->ext) {
5bbbbe32 MRL	210	int ret;
	211
	212	ret = sctp_stream_init_ext(&asoc->stream, sid);
	213	if (ret)
	214	return ret;
	215	}
	216
	217	return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
	218	}
	219
	220	int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
	221	__u16 *value)
	222	{
	223	if (sid >= asoc->stream.outcnt)
	224	return -EINVAL;
	225
05364ca0	226	if (!SCTP_SO(&asoc->stream, sid)->ext)
5bbbbe32 MRL	227	return 0;
	228
	229	return asoc->outqueue.sched->get(&asoc->stream, sid, value);
	230	}
	231
	232	void sctp_sched_dequeue_done(struct sctp_outq q, struct sctp_chunk ch)
	233	{
ef4775e3	234	if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
da1f6d4d	235	!q->asoc->peer.intl_capable) {
5bbbbe32 MRL	236	struct sctp_stream_out *sout;
	237	__u16 sid;
	238
	239	/* datamsg is not finish, so save it as current one,
	240	* in case application switch scheduler or a higher
	241	* priority stream comes in.
	242	*/
	243	sid = sctp_chunk_stream_no(ch);
05364ca0	244	sout = SCTP_SO(&q->asoc->stream, sid);
5bbbbe32 MRL	245	q->asoc->stream.out_curr = sout;
	246	return;
	247	}
	248
	249	q->asoc->stream.out_curr = NULL;
	250	q->sched->dequeue_done(q, ch);
	251	}
	252
	253	/* Auxiliary functions for the schedulers */
	254	void sctp_sched_dequeue_common(struct sctp_outq q, struct sctp_chunk ch)
	255	{
	256	list_del_init(&ch->list);
	257	list_del_init(&ch->stream_list);
	258	q->out_qlen -= ch->skb->len;
	259	}
	260
	261	int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
	262	{
	263	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
05364ca0	264	struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;
5bbbbe32	265
05364ca0	266	INIT_LIST_HEAD(&ext->outq);
5bbbbe32 MRL	267	return sched->init_sid(stream, sid, gfp);
	268	}
	269
	270	struct sctp_sched_ops sctp_sched_ops_from_stream(struct sctp_stream stream)
	271	{
	272	struct sctp_association *asoc;
	273
	274	asoc = container_of(stream, struct sctp_association, stream);
	275
	276	return asoc->outqueue.sched;
	277	}