1 /*- 2 * Copyright (c) 2007-2015 Kip Macy <kmacy@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 * 28 */ 29 30 #ifndef _SYS_BUF_RING_SC_H_ 31 #define _SYS_BUF_RING_SC_H_ 32 33 #include <machine/cpu.h> 34 struct buf_ring_sc; 35 36 struct buf_ring_sc_stats_v0 { 37 uint64_t brs_enqueues; 38 uint64_t brs_drops; 39 uint64_t brs_abdications; 40 uint64_t brs_stalls; 41 uint64_t brs_starts; 42 uint64_t brs_restarts; 43 }; 44 45 struct buf_ring_sc_consumer { 46 47 /* driver 'drain' function to remove from sw queue and place on hw queue */ 48 int (*brsc_drain) (struct buf_ring_sc *br, int avail, void *sc); 49 50 /* allow draining to continue in another context */ 51 void (*brsc_deferred) (struct buf_ring_sc *br, void *sc); 52 53 void *brsc_sc; 54 int brsc_domain; 55 int brsc_flags; 56 57 }; 58 59 /* cache line align buf ring entries */ 60 #define BR_FLAGS_ALIGNED 0x1 61 #define BR_FLAGS_NUMA 0x2 62 63 struct buf_ring_sc *buf_ring_sc_alloc(int count, struct malloc_type *type, int flags, struct buf_ring_sc_consumer *brsc); 64 void buf_ring_sc_free(struct buf_ring_sc *br, struct malloc_type *type); 65 void buf_ring_sc_reset_stats(struct buf_ring_sc *br); 66 void buf_ring_sc_get_stats_v0(struct buf_ring_sc *br, struct buf_ring_sc_stats_v0 *brss); 67 68 /** 69 * buf_ring_sc_enqueue - enqueue a buffer to the ring, possibly 70 * acquiring the consumer lock 71 * @ents: buffers to enqueue 72 * @count: number of buffers 73 * 74 * return values: 75 * - 0 - success 76 * - ENOBUFS - failure - could not enqueue all bufs 77 */ 78 int buf_ring_sc_enqueue(struct buf_ring_sc *br, void *ents[], int count, int budget); 79 80 /** 81 * buf_ring_sc_drain - check ring for entries and drain 82 * @budget: if non-zero max entries to drain 83 * if zero does a blocking acquisition 84 * 85 */ 86 void buf_ring_sc_drain(struct buf_ring_sc *br, int budget); 87 88 /** 89 * buf_ring_sc_peek - check ring for entries 90 * @ents: array of returned values 91 * @count: the size of ents 92 * 93 * returns: number of entries in ents 94 * 95 * Populate ents with up to count entries from the ring. 96 * returns the number of entries in ents 97 * To be used only by the user specified drain function, 98 * and only once per-call. 99 */ 100 int buf_ring_sc_peek(struct buf_ring_sc *br, void *ents[], uint16_t count); 101 102 /** 103 * buf_ring_sc_putback - return a buffer to the ring 104 * @new: buffer to return 105 * @idx: offset from consumer index to return it to 106 * 107 * Used to return a buffer (most likely already there) 108 * to the top of the ring at offset idx from the current 109 * consumer index. The caller should *not* have advanced 110 * the index. 111 * To be used only by the user specified drain function. 112 */ 113 void buf_ring_sc_putback(struct buf_ring_sc *br, void *new, int idx); 114 115 /** 116 * buf_ring_sc_abdicate - indicate unlock intent 117 * 118 * Mark the ring as transitioning to unowned. 119 * Returns in a critical section. Caller is responsible 120 * for calling buf_ring_sc_unlock subsequently with no 121 * intervening blocking operations 122 * This function is an *optional* optimization to give a 123 * wider window for handoff to the next consumer. 124 * To be used only by the user specified drain function. 125 */ 126 void buf_ring_sc_abdicate(struct buf_ring_sc *br); 127 128 int buf_ring_sc_count(struct buf_ring_sc *br); 129 int buf_ring_sc_empty(struct buf_ring_sc *br); 130 int buf_ring_sc_full(struct buf_ring_sc *br); 131 #endif /* BUF_RING_SC_H_ */ 132