2 * CAM IO Scheduler Interface
4 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
6 * Copyright (c) 2015 Netflix, Inc.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions, and the following disclaimer,
13 * without modification, immediately at the beginning of the file.
14 * 2. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
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 FOR
21 * 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
32 #ifndef _CAM_CAM_IOSCHED_H
33 #define _CAM_CAM_IOSCHED_H
35 /* No user-serviceable parts in here. */
38 /* Forward declare all structs to keep interface thin */
39 struct cam_iosched_softc;
40 struct sysctl_ctx_list;
46 * For 64-bit platforms, we know that uintptr_t is the same size as sbintime_t
47 * so we can store values in it. For 32-bit systems, however, uintptr_t is only
48 * 32-bits, so it won't fit. For those systems, store 24 bits of fraction and 8
49 * bits of seconds. This allows us to measure an interval of up to ~256s, which
50 * is ~200x what our current uses require. Provide some convenience functions to
51 * get the time, subtract two times and convert back to sbintime_t in a safe way
52 * that can be centralized.
55 #define CAM_IOSCHED_TIME_SHIFT 0
57 #define CAM_IOSCHED_TIME_SHIFT 8
59 static inline uintptr_t
63 /* Cast here is to avoid right shifting a signed value */
64 return (uintptr_t)((uint64_t)sbinuptime() >> CAM_IOSCHED_TIME_SHIFT);
67 static inline uintptr_t
68 cam_iosched_delta_t(uintptr_t then)
71 /* Since the types are identical, wrapping works correctly */
72 return (cam_iosched_now() - then);
75 static inline sbintime_t
76 cam_iosched_sbintime_t(uintptr_t delta)
79 /* Cast here is to widen the type so the left shift doesn't lose precision */
80 return (sbintime_t)((uint64_t)delta << CAM_IOSCHED_TIME_SHIFT);
83 typedef void (*cam_iosched_latfcn_t)(void *, sbintime_t, struct bio *);
85 int cam_iosched_init(struct cam_iosched_softc **, struct cam_periph *periph);
86 void cam_iosched_fini(struct cam_iosched_softc *);
87 void cam_iosched_sysctl_init(struct cam_iosched_softc *, struct sysctl_ctx_list *, struct sysctl_oid *);
88 struct bio *cam_iosched_next_trim(struct cam_iosched_softc *isc);
89 struct bio *cam_iosched_get_trim(struct cam_iosched_softc *isc);
90 struct bio *cam_iosched_next_bio(struct cam_iosched_softc *isc);
91 void cam_iosched_queue_work(struct cam_iosched_softc *isc, struct bio *bp);
92 void cam_iosched_flush(struct cam_iosched_softc *isc, struct devstat *stp, int err);
93 void cam_iosched_schedule(struct cam_iosched_softc *isc, struct cam_periph *periph);
94 void cam_iosched_finish_trim(struct cam_iosched_softc *isc);
95 void cam_iosched_submit_trim(struct cam_iosched_softc *isc);
96 void cam_iosched_put_back_trim(struct cam_iosched_softc *isc, struct bio *bp);
97 void cam_iosched_set_sort_queue(struct cam_iosched_softc *isc, int val);
98 int cam_iosched_has_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
99 void cam_iosched_set_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
100 void cam_iosched_clr_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
101 void cam_iosched_trim_done(struct cam_iosched_softc *isc);
102 int cam_iosched_bio_complete(struct cam_iosched_softc *isc, struct bio *bp, union ccb *done_ccb);
103 void cam_iosched_set_latfcn(struct cam_iosched_softc *isc, cam_iosched_latfcn_t, void *);
104 void cam_iosched_set_trim_goal(struct cam_iosched_softc *isc, int goal);
105 void cam_iosched_set_trim_ticks(struct cam_iosched_softc *isc, int ticks);