1 /*- 2 * CAM IO Scheduler Interface 3 * 4 * Copyright (c) 2015 Netflix, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions, and the following disclaimer, 12 * without modification, immediately at the beginning of the file. 13 * 2. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #ifndef _CAM_CAM_IOSCHED_H 32 #define _CAM_CAM_IOSCHED_H 33 34 /* No user-serviceable parts in here. */ 35 #ifdef _KERNEL 36 37 /* Forward declare all structs to keep interface thin */ 38 struct cam_iosched_softc; 39 struct sysctl_ctx_list; 40 struct sysctl_oid; 41 union ccb; 42 struct bio; 43 44 /* 45 * For 64-bit platforms, we know that uintptr_t is the same size as sbintime_t 46 * so we can store values in it. For 32-bit systems, however, uintptr_t is only 47 * 32-bits, so it won't fit. For those systems, store 24 bits of fraction and 8 48 * bits of seconds. This allows us to measure an interval of up to ~256s, which 49 * is ~200x what our current uses require. Provide some convenience functions to 50 * get the time, subtract two times and convert back to sbintime_t in a safe way 51 * that can be centralized. 52 */ 53 #ifdef __LP64__ 54 #define CAM_IOSCHED_TIME_SHIFT 0 55 #else 56 #define CAM_IOSCHED_TIME_SHIFT 8 57 #endif 58 static inline uintptr_t 59 cam_iosched_now(void) 60 { 61 62 /* Cast here is to avoid right shifting a signed value */ 63 return (uintptr_t)((uint64_t)sbinuptime() >> CAM_IOSCHED_TIME_SHIFT); 64 } 65 66 static inline uintptr_t 67 cam_iosched_delta_t(uintptr_t then) 68 { 69 70 /* Since the types are identical, wrapping works correctly */ 71 return (cam_iosched_now() - then); 72 } 73 74 static inline sbintime_t 75 cam_iosched_sbintime_t(uintptr_t delta) 76 { 77 78 /* Cast here is to widen the type so the left shift doesn't lose precision */ 79 return (sbintime_t)((uint64_t)delta << CAM_IOSCHED_TIME_SHIFT); 80 } 81 82 int cam_iosched_init(struct cam_iosched_softc **, struct cam_periph *periph); 83 void cam_iosched_fini(struct cam_iosched_softc *); 84 void cam_iosched_sysctl_init(struct cam_iosched_softc *, struct sysctl_ctx_list *, struct sysctl_oid *); 85 struct bio *cam_iosched_next_trim(struct cam_iosched_softc *isc); 86 struct bio *cam_iosched_get_trim(struct cam_iosched_softc *isc); 87 struct bio *cam_iosched_next_bio(struct cam_iosched_softc *isc); 88 void cam_iosched_queue_work(struct cam_iosched_softc *isc, struct bio *bp); 89 void cam_iosched_flush(struct cam_iosched_softc *isc, struct devstat *stp, int err); 90 void cam_iosched_schedule(struct cam_iosched_softc *isc, struct cam_periph *periph); 91 void cam_iosched_finish_trim(struct cam_iosched_softc *isc); 92 void cam_iosched_submit_trim(struct cam_iosched_softc *isc); 93 void cam_iosched_put_back_trim(struct cam_iosched_softc *isc, struct bio *bp); 94 void cam_iosched_set_sort_queue(struct cam_iosched_softc *isc, int val); 95 int cam_iosched_has_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 96 void cam_iosched_set_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 97 void cam_iosched_clr_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 98 void cam_iosched_trim_done(struct cam_iosched_softc *isc); 99 int cam_iosched_bio_complete(struct cam_iosched_softc *isc, struct bio *bp, union ccb *done_ccb); 100 101 #endif 102 #endif 103