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// 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>
/* Priority handling
* RFC DRAFT ndata section 3.2
*/
static void sctp_sched_rr_unsched_all(struct sctp_stream *stream);
static void sctp_sched_rr_next_stream(struct sctp_stream *stream)
{
struct list_head *pos;
pos = stream->rr_next->rr_list.next;
if (pos == &stream->rr_list)
pos = pos->next;
stream->rr_next = list_entry(pos, struct sctp_stream_out_ext, rr_list);
}
static void sctp_sched_rr_unsched(struct sctp_stream *stream,
struct sctp_stream_out_ext *soute)
{
if (stream->rr_next == soute)
/* Try to move to the next stream */
sctp_sched_rr_next_stream(stream);
list_del_init(&soute->rr_list);
/* If we have no other stream queued, clear next */
if (list_empty(&stream->rr_list))
stream->rr_next = NULL;
}
static void sctp_sched_rr_sched(struct sctp_stream *stream,
struct sctp_stream_out_ext *soute)
{
if (!list_empty(&soute->rr_list))
/* Already scheduled. */
return;
/* Schedule the stream */
list_add_tail(&soute->rr_list, &stream->rr_list);
if (!stream->rr_next)
stream->rr_next = soute;
}
static int sctp_sched_rr_set(struct sctp_stream *stream, __u16 sid,
__u16 prio, gfp_t gfp)
{
return 0;
}
static int sctp_sched_rr_get(struct sctp_stream *stream, __u16 sid,
__u16 *value)
{
return 0;
}
static int sctp_sched_rr_init(struct sctp_stream *stream)
{
INIT_LIST_HEAD(&stream->rr_list);
stream->rr_next = NULL;
return 0;
}
static int sctp_sched_rr_init_sid(struct sctp_stream *stream, __u16 sid,
gfp_t gfp)
{
INIT_LIST_HEAD(&SCTP_SO(stream, sid)->ext->rr_list);
return 0;
}
static void sctp_sched_rr_free_sid(struct sctp_stream *stream, __u16 sid)
{
}
static void sctp_sched_rr_enqueue(struct sctp_outq *q,
struct sctp_datamsg *msg)
{
struct sctp_stream *stream;
struct sctp_chunk *ch;
__u16 sid;
ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list);
sid = sctp_chunk_stream_no(ch);
stream = &q->asoc->stream;
sctp_sched_rr_sched(stream, SCTP_SO(stream, sid)->ext);
}
static struct sctp_chunk *sctp_sched_rr_dequeue(struct sctp_outq *q)
{
struct sctp_stream *stream = &q->asoc->stream;
struct sctp_stream_out_ext *soute;
struct sctp_chunk *ch = NULL;
/* Bail out quickly if queue is empty */
if (list_empty(&q->out_chunk_list))
goto out;
/* Find which chunk is next */
if (stream->out_curr)
soute = stream->out_curr->ext;
else
soute = stream->rr_next;
ch = list_entry(soute->outq.next, struct sctp_chunk, stream_list);
sctp_sched_dequeue_common(q, ch);
out:
return ch;
}
static void sctp_sched_rr_dequeue_done(struct sctp_outq *q,
struct sctp_chunk *ch)
{
struct sctp_stream_out_ext *soute;
__u16 sid;
/* Last chunk on that msg, move to the next stream */
sid = sctp_chunk_stream_no(ch);
soute = SCTP_SO(&q->asoc->stream, sid)->ext;
sctp_sched_rr_next_stream(&q->asoc->stream);
if (list_empty(&soute->outq))
sctp_sched_rr_unsched(&q->asoc->stream, soute);
}
static void sctp_sched_rr_sched_all(struct sctp_stream *stream)
{
struct sctp_association *asoc;
struct sctp_stream_out_ext *soute;
struct sctp_chunk *ch;
asoc = container_of(stream, struct sctp_association, stream);
list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
__u16 sid;
sid = sctp_chunk_stream_no(ch);
soute = SCTP_SO(stream, sid)->ext;
if (soute)
sctp_sched_rr_sched(stream, soute);
}
}
static void sctp_sched_rr_unsched_all(struct sctp_stream *stream)
{
struct sctp_stream_out_ext *soute, *tmp;
list_for_each_entry_safe(soute, tmp, &stream->rr_list, rr_list)
sctp_sched_rr_unsched(stream, soute);
}
static struct sctp_sched_ops sctp_sched_rr = {
.set = sctp_sched_rr_set,
.get = sctp_sched_rr_get,
.init = sctp_sched_rr_init,
.init_sid = sctp_sched_rr_init_sid,
.free_sid = sctp_sched_rr_free_sid,
.enqueue = sctp_sched_rr_enqueue,
.dequeue = sctp_sched_rr_dequeue,
.dequeue_done = sctp_sched_rr_dequeue_done,
.sched_all = sctp_sched_rr_sched_all,
.unsched_all = sctp_sched_rr_unsched_all,
};
void sctp_sched_ops_rr_init(void)
{
sctp_sched_ops_register(SCTP_SS_RR, &sctp_sched_rr);
}