cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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stream_sched_rr.c (4658B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      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 *
      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/* Priority handling
     23 * RFC DRAFT ndata section 3.2
     24 */
     25static void sctp_sched_rr_unsched_all(struct sctp_stream *stream);
     26
     27static void sctp_sched_rr_next_stream(struct sctp_stream *stream)
     28{
     29	struct list_head *pos;
     30
     31	pos = stream->rr_next->rr_list.next;
     32	if (pos == &stream->rr_list)
     33		pos = pos->next;
     34	stream->rr_next = list_entry(pos, struct sctp_stream_out_ext, rr_list);
     35}
     36
     37static void sctp_sched_rr_unsched(struct sctp_stream *stream,
     38				  struct sctp_stream_out_ext *soute)
     39{
     40	if (stream->rr_next == soute)
     41		/* Try to move to the next stream */
     42		sctp_sched_rr_next_stream(stream);
     43
     44	list_del_init(&soute->rr_list);
     45
     46	/* If we have no other stream queued, clear next */
     47	if (list_empty(&stream->rr_list))
     48		stream->rr_next = NULL;
     49}
     50
     51static void sctp_sched_rr_sched(struct sctp_stream *stream,
     52				struct sctp_stream_out_ext *soute)
     53{
     54	if (!list_empty(&soute->rr_list))
     55		/* Already scheduled. */
     56		return;
     57
     58	/* Schedule the stream */
     59	list_add_tail(&soute->rr_list, &stream->rr_list);
     60
     61	if (!stream->rr_next)
     62		stream->rr_next = soute;
     63}
     64
     65static int sctp_sched_rr_set(struct sctp_stream *stream, __u16 sid,
     66			     __u16 prio, gfp_t gfp)
     67{
     68	return 0;
     69}
     70
     71static int sctp_sched_rr_get(struct sctp_stream *stream, __u16 sid,
     72			     __u16 *value)
     73{
     74	return 0;
     75}
     76
     77static int sctp_sched_rr_init(struct sctp_stream *stream)
     78{
     79	INIT_LIST_HEAD(&stream->rr_list);
     80	stream->rr_next = NULL;
     81
     82	return 0;
     83}
     84
     85static int sctp_sched_rr_init_sid(struct sctp_stream *stream, __u16 sid,
     86				  gfp_t gfp)
     87{
     88	INIT_LIST_HEAD(&SCTP_SO(stream, sid)->ext->rr_list);
     89
     90	return 0;
     91}
     92
     93static void sctp_sched_rr_free(struct sctp_stream *stream)
     94{
     95	sctp_sched_rr_unsched_all(stream);
     96}
     97
     98static void sctp_sched_rr_enqueue(struct sctp_outq *q,
     99				  struct sctp_datamsg *msg)
    100{
    101	struct sctp_stream *stream;
    102	struct sctp_chunk *ch;
    103	__u16 sid;
    104
    105	ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list);
    106	sid = sctp_chunk_stream_no(ch);
    107	stream = &q->asoc->stream;
    108	sctp_sched_rr_sched(stream, SCTP_SO(stream, sid)->ext);
    109}
    110
    111static struct sctp_chunk *sctp_sched_rr_dequeue(struct sctp_outq *q)
    112{
    113	struct sctp_stream *stream = &q->asoc->stream;
    114	struct sctp_stream_out_ext *soute;
    115	struct sctp_chunk *ch = NULL;
    116
    117	/* Bail out quickly if queue is empty */
    118	if (list_empty(&q->out_chunk_list))
    119		goto out;
    120
    121	/* Find which chunk is next */
    122	if (stream->out_curr)
    123		soute = stream->out_curr->ext;
    124	else
    125		soute = stream->rr_next;
    126	ch = list_entry(soute->outq.next, struct sctp_chunk, stream_list);
    127
    128	sctp_sched_dequeue_common(q, ch);
    129
    130out:
    131	return ch;
    132}
    133
    134static void sctp_sched_rr_dequeue_done(struct sctp_outq *q,
    135				       struct sctp_chunk *ch)
    136{
    137	struct sctp_stream_out_ext *soute;
    138	__u16 sid;
    139
    140	/* Last chunk on that msg, move to the next stream */
    141	sid = sctp_chunk_stream_no(ch);
    142	soute = SCTP_SO(&q->asoc->stream, sid)->ext;
    143
    144	sctp_sched_rr_next_stream(&q->asoc->stream);
    145
    146	if (list_empty(&soute->outq))
    147		sctp_sched_rr_unsched(&q->asoc->stream, soute);
    148}
    149
    150static void sctp_sched_rr_sched_all(struct sctp_stream *stream)
    151{
    152	struct sctp_association *asoc;
    153	struct sctp_stream_out_ext *soute;
    154	struct sctp_chunk *ch;
    155
    156	asoc = container_of(stream, struct sctp_association, stream);
    157	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
    158		__u16 sid;
    159
    160		sid = sctp_chunk_stream_no(ch);
    161		soute = SCTP_SO(stream, sid)->ext;
    162		if (soute)
    163			sctp_sched_rr_sched(stream, soute);
    164	}
    165}
    166
    167static void sctp_sched_rr_unsched_all(struct sctp_stream *stream)
    168{
    169	struct sctp_stream_out_ext *soute, *tmp;
    170
    171	list_for_each_entry_safe(soute, tmp, &stream->rr_list, rr_list)
    172		sctp_sched_rr_unsched(stream, soute);
    173}
    174
    175static struct sctp_sched_ops sctp_sched_rr = {
    176	.set = sctp_sched_rr_set,
    177	.get = sctp_sched_rr_get,
    178	.init = sctp_sched_rr_init,
    179	.init_sid = sctp_sched_rr_init_sid,
    180	.free = sctp_sched_rr_free,
    181	.enqueue = sctp_sched_rr_enqueue,
    182	.dequeue = sctp_sched_rr_dequeue,
    183	.dequeue_done = sctp_sched_rr_dequeue_done,
    184	.sched_all = sctp_sched_rr_sched_all,
    185	.unsched_all = sctp_sched_rr_unsched_all,
    186};
    187
    188void sctp_sched_ops_rr_init(void)
    189{
    190	sctp_sched_ops_register(SCTP_SS_RR, &sctp_sched_rr);
    191}