2 * CAM IO Scheduler Interface
4 * Copyright (c) 2015 Netflix, Inc.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
31 #ifndef _CAM_CAM_IOSCHED_H
32 #define _CAM_CAM_IOSCHED_H
34 /* No user-serviceable parts in here. */
37 /* Forward declare all structs to keep interface thin */
38 struct cam_iosched_softc;
39 struct sysctl_ctx_list;
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.
54 #define CAM_IOSCHED_TIME_SHIFT 0
56 #define CAM_IOSCHED_TIME_SHIFT 8
58 static inline uintptr_t
62 /* Cast here is to avoid right shifting a signed value */
63 return (uintptr_t)((uint64_t)sbinuptime() >> CAM_IOSCHED_TIME_SHIFT);
66 static inline uintptr_t
67 cam_iosched_delta_t(uintptr_t then)
70 /* Since the types are identical, wrapping works correctly */
71 return (cam_iosched_now() - then);
74 static inline sbintime_t
75 cam_iosched_sbintime_t(uintptr_t delta)
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);
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);