1 /*- 2 * CAM IO Scheduler Interface 3 * 4 * SPDX-License-Identifier: BSD-2-Clause 5 * 6 * Copyright (c) 2015 Netflix, Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #ifndef _CAM_CAM_IOSCHED_H 31 #define _CAM_CAM_IOSCHED_H 32 33 /* No user-serviceable parts in here. */ 34 #ifdef _KERNEL 35 36 /* Forward declare all structs to keep interface thin */ 37 struct cam_iosched_softc; 38 struct sysctl_ctx_list; 39 struct sysctl_oid; 40 union ccb; 41 struct bio; 42 43 /* 44 * For 64-bit platforms, we know that uintptr_t is the same size as sbintime_t 45 * so we can store values in it. For 32-bit systems, however, uintptr_t is only 46 * 32-bits, so it won't fit. For those systems, store 24 bits of fraction and 8 47 * bits of seconds. This allows us to measure an interval of up to ~256s, which 48 * is ~200x what our current uses require. Provide some convenience functions to 49 * get the time, subtract two times and convert back to sbintime_t in a safe way 50 * that can be centralized. 51 */ 52 #ifdef __LP64__ 53 #define CAM_IOSCHED_TIME_SHIFT 0 54 #else 55 #define CAM_IOSCHED_TIME_SHIFT 8 56 #endif 57 static inline uintptr_t 58 cam_iosched_now(void) 59 { 60 61 /* Cast here is to avoid right shifting a signed value */ 62 return (uintptr_t)((uint64_t)sbinuptime() >> CAM_IOSCHED_TIME_SHIFT); 63 } 64 65 static inline uintptr_t 66 cam_iosched_delta_t(uintptr_t then) 67 { 68 69 /* Since the types are identical, wrapping works correctly */ 70 return (cam_iosched_now() - then); 71 } 72 73 static inline sbintime_t 74 cam_iosched_sbintime_t(uintptr_t delta) 75 { 76 77 /* Cast here is to widen the type so the left shift doesn't lose precision */ 78 return (sbintime_t)((uint64_t)delta << CAM_IOSCHED_TIME_SHIFT); 79 } 80 81 typedef void (*cam_iosched_latfcn_t)(void *, sbintime_t, struct bio *); 82 83 int cam_iosched_init(struct cam_iosched_softc **, struct cam_periph *periph); 84 void cam_iosched_fini(struct cam_iosched_softc *); 85 void cam_iosched_sysctl_init(struct cam_iosched_softc *, struct sysctl_ctx_list *, struct sysctl_oid *); 86 struct bio *cam_iosched_next_trim(struct cam_iosched_softc *isc); 87 struct bio *cam_iosched_get_trim(struct cam_iosched_softc *isc); 88 struct bio *cam_iosched_next_bio(struct cam_iosched_softc *isc); 89 void cam_iosched_queue_work(struct cam_iosched_softc *isc, struct bio *bp); 90 void cam_iosched_flush(struct cam_iosched_softc *isc, struct devstat *stp, int err); 91 void cam_iosched_schedule(struct cam_iosched_softc *isc, struct cam_periph *periph); 92 void cam_iosched_finish_trim(struct cam_iosched_softc *isc); 93 void cam_iosched_submit_trim(struct cam_iosched_softc *isc); 94 void cam_iosched_put_back_trim(struct cam_iosched_softc *isc, struct bio *bp); 95 void cam_iosched_set_sort_queue(struct cam_iosched_softc *isc, int val); 96 int cam_iosched_has_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 97 void cam_iosched_set_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 98 void cam_iosched_clr_work_flags(struct cam_iosched_softc *isc, uint32_t flags); 99 void cam_iosched_trim_done(struct cam_iosched_softc *isc); 100 int cam_iosched_bio_complete(struct cam_iosched_softc *isc, struct bio *bp, union ccb *done_ccb); 101 void cam_iosched_set_latfcn(struct cam_iosched_softc *isc, cam_iosched_latfcn_t, void *); 102 void cam_iosched_set_trim_goal(struct cam_iosched_softc *isc, int goal); 103 void cam_iosched_set_trim_ticks(struct cam_iosched_softc *isc, int ticks); 104 #endif 105 #endif 106