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/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2016-2017 Intel Corporation
*/
#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_event_ring.h>
#include "sw_evdev.h"
#define PORT_ENQUEUE_MAX_BURST_SIZE 64
static inline void
sw_event_release(struct sw_port *p, uint8_t index)
{
/*
* Drops the next outstanding event in our history. Used on dequeue
* to clear any history before dequeuing more events.
*/
RTE_SET_USED(index);
/* create drop message */
struct rte_event ev;
ev.op = sw_qe_flag_map[RTE_EVENT_OP_RELEASE];
uint16_t free_count;
rte_event_ring_enqueue_burst(p->rx_worker_ring, &ev, 1, &free_count);
/* each release returns one credit */
p->outstanding_releases--;
p->inflight_credits++;
}
/*
* special-case of rte_event_ring enqueue, with overriding the ops member on
* the events that get written to the ring.
*/
static inline unsigned int
enqueue_burst_with_ops(struct rte_event_ring *r, const struct rte_event *events,
unsigned int n, uint8_t *ops)
{
struct rte_event tmp_evs[PORT_ENQUEUE_MAX_BURST_SIZE];
unsigned int i;
memcpy(tmp_evs, events, n * sizeof(events[0]));
for (i = 0; i < n; i++)
tmp_evs[i].op = ops[i];
return rte_event_ring_enqueue_burst(r, tmp_evs, n, NULL);
}
uint16_t
sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num)
{
int32_t i;
uint8_t new_ops[PORT_ENQUEUE_MAX_BURST_SIZE];
struct sw_port *p = port;
struct sw_evdev *sw = (void *)p->sw;
uint32_t sw_inflights = rte_atomic32_read(&sw->inflights);
uint32_t credit_update_quanta = sw->credit_update_quanta;
int new = 0;
if (num > PORT_ENQUEUE_MAX_BURST_SIZE)
num = PORT_ENQUEUE_MAX_BURST_SIZE;
for (i = 0; i < num; i++)
new += (ev[i].op == RTE_EVENT_OP_NEW);
if (unlikely(new > 0 && p->inflight_max < sw_inflights))
return 0;
if (p->inflight_credits < new) {
/* check if event enqueue brings port over max threshold */
if (sw_inflights + credit_update_quanta > sw->nb_events_limit)
return 0;
rte_atomic32_add(&sw->inflights, credit_update_quanta);
p->inflight_credits += (credit_update_quanta);
/* If there are fewer inflight credits than new events, limit
* the number of enqueued events.
*/
num = (p->inflight_credits < new) ? p->inflight_credits : new;
}
for (i = 0; i < num; i++) {
int op = ev[i].op;
int outstanding = p->outstanding_releases > 0;
const uint8_t invalid_qid = (ev[i].queue_id >= sw->qid_count);
p->inflight_credits -= (op == RTE_EVENT_OP_NEW);
p->inflight_credits += (op == RTE_EVENT_OP_RELEASE) *
outstanding;
new_ops[i] = sw_qe_flag_map[op];
new_ops[i] &= ~(invalid_qid << QE_FLAG_VALID_SHIFT);
/* FWD and RELEASE packets will both resolve to taken (assuming
* correct usage of the API), providing very high correct
* prediction rate.
*/
if ((new_ops[i] & QE_FLAG_COMPLETE) && outstanding)
p->outstanding_releases--;
/* error case: branch to avoid touching p->stats */
if (unlikely(invalid_qid && op != RTE_EVENT_OP_RELEASE)) {
p->stats.rx_dropped++;
p->inflight_credits++;
}
}
/* returns number of events actually enqueued */
uint32_t enq = enqueue_burst_with_ops(p->rx_worker_ring, ev, i,
new_ops);
if (p->outstanding_releases == 0 && p->last_dequeue_burst_sz != 0) {
uint64_t burst_ticks = rte_get_timer_cycles() -
p->last_dequeue_ticks;
uint64_t burst_pkt_ticks =
burst_ticks / p->last_dequeue_burst_sz;
p->avg_pkt_ticks -= p->avg_pkt_ticks / NUM_SAMPLES;
p->avg_pkt_ticks += burst_pkt_ticks / NUM_SAMPLES;
p->last_dequeue_ticks = 0;
}
/* Replenish credits if enough releases are performed */
if (p->inflight_credits >= credit_update_quanta * 2) {
rte_atomic32_sub(&sw->inflights, credit_update_quanta);
p->inflight_credits -= credit_update_quanta;
}
return enq;
}
uint16_t
sw_event_dequeue_burst(void *port, struct rte_event *ev, uint16_t num,
uint64_t wait)
{
RTE_SET_USED(wait);
struct sw_port *p = (void *)port;
struct rte_event_ring *ring = p->cq_worker_ring;
/* check that all previous dequeues have been released */
if (p->implicit_release) {
struct sw_evdev *sw = (void *)p->sw;
uint32_t credit_update_quanta = sw->credit_update_quanta;
uint16_t out_rels = p->outstanding_releases;
uint16_t i;
for (i = 0; i < out_rels; i++)
sw_event_release(p, i);
/* Replenish credits if enough releases are performed */
if (p->inflight_credits >= credit_update_quanta * 2) {
rte_atomic32_sub(&sw->inflights, credit_update_quanta);
p->inflight_credits -= credit_update_quanta;
}
}
/* returns number of events actually dequeued */
uint16_t ndeq = rte_event_ring_dequeue_burst(ring, ev, num, NULL);
if (unlikely(ndeq == 0)) {
p->zero_polls++;
p->total_polls++;
goto end;
}
p->outstanding_releases += ndeq;
p->last_dequeue_burst_sz = ndeq;
p->last_dequeue_ticks = rte_get_timer_cycles();
p->poll_buckets[(ndeq - 1) >> SW_DEQ_STAT_BUCKET_SHIFT]++;
p->total_polls++;
end:
return ndeq;
}
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