1 /*- 2 * CAM IO Scheduler Interface 3 * 4 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 5 * 6 * Copyright (c) 2015 Netflix, Inc. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions, and the following disclaimer, 14 * without modification, immediately at the beginning of the file. 15 * 2. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #ifndef _CAM_CAM_IOSCHED_H 34 #define _CAM_CAM_IOSCHED_H 35 36 /* No user-serviceable parts in here. */ 37 #ifdef _KERNEL 38 39 /* Forward declare all structs to keep interface thin */ 40 struct cam_iosched_softc; 41 struct sysctl_ctx_list; 42 struct sysctl_oid; 43 union ccb; 44 struct bio; 45 46 /* 47 * For 64-bit platforms, we know that uintptr_t is the same size as sbintime_t 48 * so we can store values in it. For 32-bit systems, however, uintptr_t is only 49 * 32-bits, so it won't fit. For those systems, store 24 bits of fraction and 8 50 * bits of seconds. This allows us to measure an interval of up to ~256s, which 51 * is ~200x what our current uses require. Provide some convenience functions to 52 * get the time, subtract two times and convert back to sbintime_t in a safe way 53 * that can be centralized. 54 */ 55 #ifdef __LP64__ 56 #define CAM_IOSCHED_TIME_SHIFT 0 57 #else 58 #define CAM_IOSCHED_TIME_SHIFT 8 59 #endif 60 static inline uintptr_t 61 cam_iosched_now(void) 62 { 63 64 /* Cast here is to avoid right shifting a signed value */ 65 return (uintptr_t)((uint64_t)sbinuptime() >> CAM_IOSCHED_TIME_SHIFT); 66 } 67 68 static inline uintptr_t 69 cam_iosched_delta_t(uintptr_t then) 70 { 71 72 /* Since the types are identical, wrapping works correctly */ 73 return (cam_iosched_now() - then); 74 } 75 76 static inline sbintime_t 77 cam_iosched_sbintime_t(uintptr_t delta) 78 { 79 80 /* Cast here is to widen the type so the left shift doesn't lose precision */ 81 return (sbintime_t)((uint64_t)delta << CAM_IOSCHED_TIME_SHIFT); 82 } 83 84 int cam_iosched_init(struct cam_iosched_softc **, struct cam_periph *periph); 85 void cam_iosched_fini(struct cam_iosched_softc *); 86 void cam_iosched_sysctl_init(struct cam_iosched_softc *, struct sysctl_ctx_list *, struct sysctl_oid *); 87 struct bio *cam_iosched_next_trim(struct cam_iosched_softc *isc); 88 struct bio *cam_iosched_get_trim(struct cam_iosched_softc *isc); 89 struct bio *cam_iosched_next_bio(struct cam_iosched_softc *isc); 90 void cam_iosched_queue_work(struct cam_iosched_softc *isc, struct bio *bp); 91 void cam_iosched_flush(struct cam_iosched_softc *isc, struct devstat *stp, int err); 92 void cam_iosched_schedule(struct cam_iosched_softc *isc, struct cam_periph *periph); 93 void cam_iosched_finish_trim(struct cam_iosched_softc *isc); 94 void cam_iosched_submit_trim(struct cam_iosched_softc *isc); 95 void cam_iosched_put_back_trim(struct cam_iosched_softc *isc, struct bio *bp); 96 void cam_iosched_set_sort_queue(struct cam_iosched_softc *isc, int val); 97 int cam_iosched_has_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 98 void cam_iosched_set_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 99 void cam_iosched_clr_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 100 void cam_iosched_trim_done(struct cam_iosched_softc *isc); 101 int cam_iosched_bio_complete(struct cam_iosched_softc *isc, struct bio *bp, union ccb *done_ccb); 102 103 #endif 104 #endif 105