/*-
* CAM IO Scheduler Interface
*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2015 Netflix, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _CAM_CAM_IOSCHED_H
#define _CAM_CAM_IOSCHED_H
/* No user-serviceable parts in here. */
#ifdef _KERNEL
/* Forward declare all structs to keep interface thin */
struct cam_iosched_softc;
struct sysctl_ctx_list;
struct sysctl_oid;
union ccb;
struct bio;
/*
* For 64-bit platforms, we know that uintptr_t is the same size as sbintime_t
* so we can store values in it. For 32-bit systems, however, uintptr_t is only
* 32-bits, so it won't fit. For those systems, store 24 bits of fraction and 8
* bits of seconds. This allows us to measure an interval of up to ~256s, which
* is ~200x what our current uses require. Provide some convenience functions to
* get the time, subtract two times and convert back to sbintime_t in a safe way
* that can be centralized.
*/
#ifdef __LP64__
#define CAM_IOSCHED_TIME_SHIFT 0
#else
#define CAM_IOSCHED_TIME_SHIFT 8
#endif
static inline uintptr_t
cam_iosched_now(void)
{
/* Cast here is to avoid right shifting a signed value */
return (uintptr_t)((uint64_t)sbinuptime() >> CAM_IOSCHED_TIME_SHIFT);
}
static inline uintptr_t
cam_iosched_delta_t(uintptr_t then)
{
/* Since the types are identical, wrapping works correctly */
return (cam_iosched_now() - then);
}
static inline sbintime_t
cam_iosched_sbintime_t(uintptr_t delta)
{
/* Cast here is to widen the type so the left shift doesn't lose precision */
return (sbintime_t)((uint64_t)delta << CAM_IOSCHED_TIME_SHIFT);
}
typedef void (*cam_iosched_latfcn_t)(void *, sbintime_t, struct bio *);
int cam_iosched_init(struct cam_iosched_softc **, struct cam_periph *periph);
void cam_iosched_fini(struct cam_iosched_softc *);
void cam_iosched_sysctl_init(struct cam_iosched_softc *, struct sysctl_ctx_list *, struct sysctl_oid *);
struct bio *cam_iosched_next_trim(struct cam_iosched_softc *isc);
struct bio *cam_iosched_get_trim(struct cam_iosched_softc *isc);
struct bio *cam_iosched_next_bio(struct cam_iosched_softc *isc);
void cam_iosched_queue_work(struct cam_iosched_softc *isc, struct bio *bp);
void cam_iosched_flush(struct cam_iosched_softc *isc, struct devstat *stp, int err);
void cam_iosched_schedule(struct cam_iosched_softc *isc, struct cam_periph *periph);
void cam_iosched_finish_trim(struct cam_iosched_softc *isc);
void cam_iosched_submit_trim(struct cam_iosched_softc *isc);
void cam_iosched_put_back_trim(struct cam_iosched_softc *isc, struct bio *bp);
void cam_iosched_set_sort_queue(struct cam_iosched_softc *isc, int val);
int cam_iosched_has_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
void cam_iosched_set_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
void cam_iosched_clr_work_flags(struct cam_iosched_softc *isc, uint32_t flags);
void cam_iosched_trim_done(struct cam_iosched_softc *isc);
int cam_iosched_bio_complete(struct cam_iosched_softc *isc, struct bio *bp, union ccb *done_ccb);
void cam_iosched_set_latfcn(struct cam_iosched_softc *isc, cam_iosched_latfcn_t, void *);
void cam_iosched_set_trim_goal(struct cam_iosched_softc *isc, int goal);
void cam_iosched_set_trim_ticks(struct cam_iosched_softc *isc, int ticks);
#endif
#endif
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