/*-
* CAM request queue management definitions.
*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 1997 Justin T. Gibbs.
* All rights reserved.
*
* 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,
* without modification, immediately at the beginning of the file.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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_QUEUE_H
#define _CAM_CAM_QUEUE_H 1
#ifdef _KERNEL
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/queue.h>
#include <cam/cam.h>
/*
* This structure implements a heap based priority queue. The queue
* assumes that the objects stored in it begin with a cam_qentry
* structure holding the priority information used to sort the objects.
* This structure is opaque to clients (outside of the XPT layer) to allow
* the implementation to change without affecting them.
*/
struct camq {
cam_pinfo **queue_array;
int array_size;
int entries;
uint32_t generation;
uint32_t qfrozen_cnt;
};
TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr);
LIST_HEAD(ccb_hdr_list, ccb_hdr);
SLIST_HEAD(ccb_hdr_slist, ccb_hdr);
struct cam_ccbq {
struct camq queue;
struct ccb_hdr_tailq queue_extra_head;
int queue_extra_entries;
int total_openings;
int allocated;
int dev_openings;
int dev_active;
};
struct cam_ed;
struct cam_devq {
struct mtx send_mtx;
struct camq send_queue;
int send_openings;
int send_active;
};
struct cam_devq *cam_devq_alloc(int devices, int openings);
int cam_devq_init(struct cam_devq *devq, int devices,
int openings);
void cam_devq_free(struct cam_devq *devq);
uint32_t cam_devq_resize(struct cam_devq *camq, int openings);
/*
* Allocate a cam_ccb_queue structure and initialize it.
*/
struct cam_ccbq *cam_ccbq_alloc(int openings);
uint32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices);
int cam_ccbq_init(struct cam_ccbq *ccbq, int openings);
void cam_ccbq_free(struct cam_ccbq *ccbq);
void cam_ccbq_fini(struct cam_ccbq *ccbq);
/*
* Resize a cam queue
*/
uint32_t camq_resize(struct camq *queue, int new_size);
/*
* Initialize a camq structure. Return 0 on success, 1 on failure.
*/
int camq_init(struct camq *camq, int size);
/*
* Finialize any internal storage or state of a cam_queue.
*/
void camq_fini(struct camq *queue);
/*
* cam_queue_insert: Given a CAM queue with at least one open spot,
* insert the new entry maintaining order.
*/
void camq_insert(struct camq *queue, cam_pinfo *new_entry);
/*
* camq_remove: Remove and arbitrary entry from the queue maintaining
* queue order.
*/
cam_pinfo *camq_remove(struct camq *queue, int index);
#define CAMQ_HEAD 1 /* Head of queue index */
/* Index the first element in the heap */
#define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD])
/* Get the first element priority. */
#define CAMQ_GET_PRIO(camq) (((camq)->entries > 0) ? \
((camq)->queue_array[CAMQ_HEAD]->priority) : 0)
/*
* camq_change_priority: Raise or lower the priority of an entry
* maintaining queue order.
*/
void camq_change_priority(struct camq *queue, int index,
uint32_t new_priority);
static __inline int
cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq)
{
return (ccbq->queue.entries + ccbq->queue_extra_entries);
}
static __inline void
cam_ccbq_take_opening(struct cam_ccbq *ccbq)
{
ccbq->allocated++;
}
static __inline void
cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb)
{
struct ccb_hdr *old_ccb;
struct camq *queue = &ccbq->queue;
KASSERT((new_ccb->ccb_h.func_code & XPT_FC_QUEUED) != 0 &&
(new_ccb->ccb_h.func_code & XPT_FC_USER_CCB) == 0,
("%s: Cannot queue ccb %p func_code %#x", __func__, new_ccb,
new_ccb->ccb_h.func_code));
/*
* If queue is already full, try to resize.
* If resize fail, push CCB with lowest priority out to the TAILQ.
*/
if (queue->entries == queue->array_size &&
camq_resize(&ccbq->queue, queue->array_size * 2) != CAM_REQ_CMP) {
old_ccb = (struct ccb_hdr *)camq_remove(queue, queue->entries);
TAILQ_INSERT_HEAD(&ccbq->queue_extra_head, old_ccb,
xpt_links.tqe);
old_ccb->pinfo.index = CAM_EXTRAQ_INDEX;
ccbq->queue_extra_entries++;
}
camq_insert(queue, &new_ccb->ccb_h.pinfo);
}
static __inline void
cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb)
{
struct ccb_hdr *cccb, *bccb;
struct camq *queue = &ccbq->queue;
cam_pinfo *removed_entry __unused;
/* If the CCB is on the TAILQ, remove it from there. */
if (ccb->ccb_h.pinfo.index == CAM_EXTRAQ_INDEX) {
TAILQ_REMOVE(&ccbq->queue_extra_head, &ccb->ccb_h,
xpt_links.tqe);
ccb->ccb_h.pinfo.index = CAM_UNQUEUED_INDEX;
ccbq->queue_extra_entries--;
return;
}
removed_entry = camq_remove(queue, ccb->ccb_h.pinfo.index);
KASSERT(removed_entry == &ccb->ccb_h.pinfo,
("%s: Removed wrong entry from queue (%p != %p)", __func__,
removed_entry, &ccb->ccb_h.pinfo));
/*
* If there are some CCBs on TAILQ, find the best one and move it
* to the emptied space in the queue.
*/
bccb = TAILQ_FIRST(&ccbq->queue_extra_head);
if (bccb == NULL)
return;
TAILQ_FOREACH(cccb, &ccbq->queue_extra_head, xpt_links.tqe) {
if (bccb->pinfo.priority > cccb->pinfo.priority ||
(bccb->pinfo.priority == cccb->pinfo.priority &&
GENERATIONCMP(bccb->pinfo.generation, >,
cccb->pinfo.generation)))
bccb = cccb;
}
TAILQ_REMOVE(&ccbq->queue_extra_head, bccb, xpt_links.tqe);
ccbq->queue_extra_entries--;
camq_insert(queue, &bccb->pinfo);
}
static __inline union ccb *
cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index)
{
return((union ccb *)ccbq->queue.queue_array[index]);
}
static __inline void
cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb)
{
send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX;
ccbq->dev_active++;
ccbq->dev_openings--;
}
static __inline void
cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb)
{
ccbq->dev_active--;
ccbq->dev_openings++;
}
static __inline void
cam_ccbq_release_opening(struct cam_ccbq *ccbq)
{
ccbq->allocated--;
}
#endif /* _KERNEL */
#endif /* _CAM_CAM_QUEUE_H */
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