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 */
37struct cam_iosched_softc;
38struct sysctl_ctx_list;
39struct sysctl_oid;
40union ccb;
41struct 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
57static inline uintptr_t
58cam_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
65static inline uintptr_t
66cam_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
73static inline sbintime_t
74cam_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
81typedef void (*cam_iosched_latfcn_t)(void *, sbintime_t, struct bio *);
82typedef void (*cam_iosched_schedule_t)(struct cam_periph *periph);
83
84int cam_iosched_init(struct cam_iosched_softc **, struct cam_periph *periph,
85 const struct disk *dp, cam_iosched_schedule_t schedfnp);
86void cam_iosched_fini(struct cam_iosched_softc *);
87void cam_iosched_sysctl_init(struct cam_iosched_softc *, struct sysctl_ctx_list *, struct sysctl_oid *);
88struct bio *cam_iosched_next_trim(struct cam_iosched_softc *isc);
89struct bio *cam_iosched_get_trim(struct cam_iosched_softc *isc);
90struct bio *cam_iosched_next_bio(struct cam_iosched_softc *isc);
91void cam_iosched_queue_work(struct cam_iosched_softc *isc, struct bio *bp);
92void cam_iosched_flush(struct cam_iosched_softc *isc, struct devstat *stp, int err);
93void cam_iosched_schedule(struct cam_iosched_softc *isc, struct cam_periph *periph);
94void cam_iosched_finish_trim(struct cam_iosched_softc *isc);
95void cam_iosched_submit_trim(struct cam_iosched_softc *isc);
96void cam_iosched_put_back_trim(struct cam_iosched_softc *isc, struct bio *bp);
97void cam_iosched_set_sort_queue(struct cam_iosched_softc *isc, int val);
98int cam_iosched_has_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
99void cam_iosched_set_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
100void cam_iosched_clr_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
101void cam_iosched_trim_done(struct cam_iosched_softc *isc);
102int cam_iosched_bio_complete(struct cam_iosched_softc *isc, struct bio *bp, union ccb *done_ccb);
103void cam_iosched_set_latfcn(struct cam_iosched_softc *isc, cam_iosched_latfcn_t, void *);
104void cam_iosched_set_trim_goal(struct cam_iosched_softc *isc, int goal);
105void cam_iosched_set_trim_ticks(struct cam_iosched_softc *isc, int ticks);
106#endif
107#endif