1 /*- 2 * BSD LICENSE 3 * 4 * Copyright(c) 2016-2017 Intel Corporation. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * * Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * * Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in 14 * the documentation and/or other materials provided with the 15 * distribution. 16 * * Neither the name of Intel Corporation nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <rte_atomic.h> 34 #include <rte_cycles.h> 35 36 #include "sw_evdev.h" 37 #include "event_ring.h" 38 39 #define PORT_ENQUEUE_MAX_BURST_SIZE 64 40 41 static inline void 42 sw_event_release(struct sw_port *p, uint8_t index) 43 { 44 /* 45 * Drops the next outstanding event in our history. Used on dequeue 46 * to clear any history before dequeuing more events. 47 */ 48 RTE_SET_USED(index); 49 50 /* create drop message */ 51 struct rte_event ev; 52 ev.op = sw_qe_flag_map[RTE_EVENT_OP_RELEASE]; 53 54 uint16_t free_count; 55 qe_ring_enqueue_burst(p->rx_worker_ring, &ev, 1, &free_count); 56 57 /* each release returns one credit */ 58 p->outstanding_releases--; 59 p->inflight_credits++; 60 } 61 62 uint16_t 63 sw_event_enqueue_burst(void *port, const struct rte_event ev[], uint16_t num) 64 { 65 int32_t i; 66 uint8_t new_ops[PORT_ENQUEUE_MAX_BURST_SIZE]; 67 struct sw_port *p = port; 68 struct sw_evdev *sw = (void *)p->sw; 69 uint32_t sw_inflights = rte_atomic32_read(&sw->inflights); 70 71 if (unlikely(p->inflight_max < sw_inflights)) 72 return 0; 73 74 if (num > PORT_ENQUEUE_MAX_BURST_SIZE) 75 num = PORT_ENQUEUE_MAX_BURST_SIZE; 76 77 if (p->inflight_credits < num) { 78 /* check if event enqueue brings port over max threshold */ 79 uint32_t credit_update_quanta = sw->credit_update_quanta; 80 if (sw_inflights + credit_update_quanta > sw->nb_events_limit) 81 return 0; 82 83 rte_atomic32_add(&sw->inflights, credit_update_quanta); 84 p->inflight_credits += (credit_update_quanta); 85 86 if (p->inflight_credits < num) 87 return 0; 88 } 89 90 uint32_t forwards = 0; 91 for (i = 0; i < num; i++) { 92 int op = ev[i].op; 93 int outstanding = p->outstanding_releases > 0; 94 const uint8_t invalid_qid = (ev[i].queue_id >= sw->qid_count); 95 96 p->inflight_credits -= (op == RTE_EVENT_OP_NEW); 97 p->inflight_credits += (op == RTE_EVENT_OP_RELEASE) * 98 outstanding; 99 forwards += (op == RTE_EVENT_OP_FORWARD); 100 101 new_ops[i] = sw_qe_flag_map[op]; 102 new_ops[i] &= ~(invalid_qid << QE_FLAG_VALID_SHIFT); 103 104 /* FWD and RELEASE packets will both resolve to taken (assuming 105 * correct usage of the API), providing very high correct 106 * prediction rate. 107 */ 108 if ((new_ops[i] & QE_FLAG_COMPLETE) && outstanding) 109 p->outstanding_releases--; 110 111 /* error case: branch to avoid touching p->stats */ 112 if (unlikely(invalid_qid)) { 113 p->stats.rx_dropped++; 114 p->inflight_credits++; 115 } 116 } 117 118 /* handle directed port forward credits */ 119 p->inflight_credits -= forwards * p->is_directed; 120 121 /* returns number of events actually enqueued */ 122 uint32_t enq = qe_ring_enqueue_burst_with_ops(p->rx_worker_ring, ev, i, 123 new_ops); 124 if (p->outstanding_releases == 0 && p->last_dequeue_burst_sz != 0) { 125 uint64_t burst_ticks = rte_get_timer_cycles() - 126 p->last_dequeue_ticks; 127 uint64_t burst_pkt_ticks = 128 burst_ticks / p->last_dequeue_burst_sz; 129 p->avg_pkt_ticks -= p->avg_pkt_ticks / NUM_SAMPLES; 130 p->avg_pkt_ticks += burst_pkt_ticks / NUM_SAMPLES; 131 p->last_dequeue_ticks = 0; 132 } 133 return enq; 134 } 135 136 uint16_t 137 sw_event_enqueue(void *port, const struct rte_event *ev) 138 { 139 return sw_event_enqueue_burst(port, ev, 1); 140 } 141 142 uint16_t 143 sw_event_dequeue_burst(void *port, struct rte_event *ev, uint16_t num, 144 uint64_t wait) 145 { 146 RTE_SET_USED(wait); 147 struct sw_port *p = (void *)port; 148 struct sw_evdev *sw = (void *)p->sw; 149 struct qe_ring *ring = p->cq_worker_ring; 150 uint32_t credit_update_quanta = sw->credit_update_quanta; 151 152 /* check that all previous dequeues have been released */ 153 if (!p->is_directed) { 154 uint16_t out_rels = p->outstanding_releases; 155 uint16_t i; 156 for (i = 0; i < out_rels; i++) 157 sw_event_release(p, i); 158 } 159 160 /* returns number of events actually dequeued */ 161 uint16_t ndeq = qe_ring_dequeue_burst(ring, ev, num); 162 if (unlikely(ndeq == 0)) { 163 p->outstanding_releases = 0; 164 p->zero_polls++; 165 p->total_polls++; 166 goto end; 167 } 168 169 /* only add credits for directed ports - LB ports send RELEASEs */ 170 p->inflight_credits += ndeq * p->is_directed; 171 p->outstanding_releases = ndeq; 172 p->last_dequeue_burst_sz = ndeq; 173 p->last_dequeue_ticks = rte_get_timer_cycles(); 174 p->poll_buckets[(ndeq - 1) >> SW_DEQ_STAT_BUCKET_SHIFT]++; 175 p->total_polls++; 176 177 end: 178 if (p->inflight_credits >= credit_update_quanta * 2 && 179 p->inflight_credits > credit_update_quanta + ndeq) { 180 rte_atomic32_sub(&sw->inflights, credit_update_quanta); 181 p->inflight_credits -= credit_update_quanta; 182 } 183 return ndeq; 184 } 185 186 uint16_t 187 sw_event_dequeue(void *port, struct rte_event *ev, uint64_t wait) 188 { 189 return sw_event_dequeue_burst(port, ev, 1, wait); 190 } 191