/*-
* CAM request queue management functions.
*
* 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.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_queue.h>
#include <cam/cam_debug.h>
static MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers");
static MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers");
static MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers");
static void heap_up(cam_pinfo **queue_array, int new_index);
static void heap_down(cam_pinfo **queue_array, int index,
int last_index);
int
camq_init(struct camq *camq, int size)
{
bzero(camq, sizeof(*camq));
camq->array_size = size;
if (camq->array_size != 0) {
/*
* Heap algorithms like everything numbered from 1, so
* allocate one more to account for 0 base.
*/
camq->queue_array = malloc((size + 1) * sizeof(cam_pinfo*),
M_CAMQ, M_NOWAIT);
if (camq->queue_array == NULL) {
printf("camq_init: - cannot malloc array!\n");
return (1);
}
}
return (0);
}
/*
* Free a camq structure. This should only be called if a controller
* driver fails somehow during its attach routine or is unloaded and has
* obtained a camq structure. The XPT should ensure that the queue
* is empty before calling this routine.
*/
void
camq_fini(struct camq *queue)
{
if (queue->queue_array != NULL) {
free(queue->queue_array, M_CAMQ);
}
}
uint32_t
camq_resize(struct camq *queue, int new_size)
{
cam_pinfo **new_array;
KASSERT(new_size >= queue->entries, ("camq_resize: "
"New queue size can't accommodate queued entries (%d < %d).",
new_size, queue->entries));
new_array = malloc((new_size + 1) * sizeof(cam_pinfo *), M_CAMQ,
M_NOWAIT);
if (new_array == NULL) {
/* Couldn't satisfy request */
return (CAM_RESRC_UNAVAIL);
}
/*
* Heap algorithms like everything numbered from 1, so
* remember that our pointer into the heap array is offset
* by one element.
*/
if (queue->queue_array != NULL) {
bcopy(queue->queue_array, new_array,
(queue->entries + 1) * sizeof(cam_pinfo *));
free(queue->queue_array, M_CAMQ);
}
queue->queue_array = new_array;
queue->array_size = new_size;
return (CAM_REQ_CMP);
}
/*
* camq_insert: Given an array of cam_pinfo* elememnts with
* the Heap(1, num_elements) property and array_size - num_elements >= 1,
* output Heap(1, num_elements+1) including new_entry in the array.
*/
void
camq_insert(struct camq *queue, cam_pinfo *new_entry)
{
KASSERT(queue->entries < queue->array_size,
("camq_insert: Attempt to insert into a full queue (%d >= %d)",
queue->entries, queue->array_size));
queue->entries++;
queue->queue_array[queue->entries] = new_entry;
new_entry->index = queue->entries;
if (queue->entries != 0)
heap_up(queue->queue_array, queue->entries);
}
/*
* camq_remove: Given an array of cam_pinfo* elevements with the
* Heap(1, num_elements) property and an index such that 1 <= index <=
* num_elements, remove that entry and restore the Heap(1, num_elements-1)
* property.
*/
cam_pinfo *
camq_remove(struct camq *queue, int index)
{
cam_pinfo *removed_entry;
if (index <= 0 || index > queue->entries)
panic("%s: Attempt to remove out-of-bounds index %d "
"from queue %p of size %d", __func__, index, queue,
queue->entries);
removed_entry = queue->queue_array[index];
if (queue->entries != index) {
queue->queue_array[index] = queue->queue_array[queue->entries];
queue->queue_array[index]->index = index;
heap_down(queue->queue_array, index, queue->entries - 1);
}
removed_entry->index = CAM_UNQUEUED_INDEX;
queue->entries--;
return (removed_entry);
}
/*
* camq_change_priority: Given an array of cam_pinfo* elements with the
* Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
* and a new priority for the element at index, change the priority of
* element index and restore the Heap(0, num_elements) property.
*/
void
camq_change_priority(struct camq *queue, int index, uint32_t new_priority)
{
if (new_priority > queue->queue_array[index]->priority) {
queue->queue_array[index]->priority = new_priority;
heap_down(queue->queue_array, index, queue->entries);
} else {
/* new_priority <= old_priority */
queue->queue_array[index]->priority = new_priority;
heap_up(queue->queue_array, index);
}
}
struct cam_devq *
cam_devq_alloc(int devices, int openings)
{
struct cam_devq *devq;
devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT);
if (devq == NULL) {
printf("cam_devq_alloc: - cannot malloc!\n");
return (NULL);
}
if (cam_devq_init(devq, devices, openings) != 0) {
free(devq, M_CAMDEVQ);
return (NULL);
}
return (devq);
}
int
cam_devq_init(struct cam_devq *devq, int devices, int openings)
{
bzero(devq, sizeof(*devq));
mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF);
if (camq_init(&devq->send_queue, devices) != 0)
return (1);
devq->send_openings = openings;
devq->send_active = 0;
return (0);
}
void
cam_devq_free(struct cam_devq *devq)
{
camq_fini(&devq->send_queue);
mtx_destroy(&devq->send_mtx);
free(devq, M_CAMDEVQ);
}
uint32_t
cam_devq_resize(struct cam_devq *camq, int devices)
{
uint32_t retval;
retval = camq_resize(&camq->send_queue, devices);
return (retval);
}
struct cam_ccbq *
cam_ccbq_alloc(int openings)
{
struct cam_ccbq *ccbq;
ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT);
if (ccbq == NULL) {
printf("cam_ccbq_alloc: - cannot malloc!\n");
return (NULL);
}
if (cam_ccbq_init(ccbq, openings) != 0) {
free(ccbq, M_CAMCCBQ);
return (NULL);
}
return (ccbq);
}
void
cam_ccbq_free(struct cam_ccbq *ccbq)
{
if (ccbq) {
cam_ccbq_fini(ccbq);
free(ccbq, M_CAMCCBQ);
}
}
uint32_t
cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
{
int delta;
delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
ccbq->total_openings += delta;
ccbq->dev_openings += delta;
new_size = imax(64, 1 << fls(new_size + new_size / 2));
if (new_size > ccbq->queue.array_size)
return (camq_resize(&ccbq->queue, new_size));
else
return (CAM_REQ_CMP);
}
int
cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
{
bzero(ccbq, sizeof(*ccbq));
if (camq_init(&ccbq->queue,
imax(64, 1 << fls(openings + openings / 2))) != 0)
return (1);
ccbq->total_openings = openings;
ccbq->dev_openings = openings;
return (0);
}
void
cam_ccbq_fini(struct cam_ccbq *ccbq)
{
camq_fini(&ccbq->queue);
}
/*
* Heap routines for manipulating CAM queues.
*/
/*
* queue_cmp: Given an array of cam_pinfo* elements and indexes i
* and j, return less than 0, 0, or greater than 0 if i is less than,
* equal too, or greater than j respectively.
*/
static __inline int
queue_cmp(cam_pinfo **queue_array, int i, int j)
{
if (queue_array[i]->priority == queue_array[j]->priority)
return ( queue_array[i]->generation
- queue_array[j]->generation );
else
return ( queue_array[i]->priority
- queue_array[j]->priority );
}
/*
* swap: Given an array of cam_pinfo* elements and indexes i and j,
* exchange elements i and j.
*/
static __inline void
swap(cam_pinfo **queue_array, int i, int j)
{
cam_pinfo *temp_qentry;
temp_qentry = queue_array[j];
queue_array[j] = queue_array[i];
queue_array[i] = temp_qentry;
queue_array[j]->index = j;
queue_array[i]->index = i;
}
/*
* heap_up: Given an array of cam_pinfo* elements with the
* Heap(1, new_index-1) property and a new element in location
* new_index, output Heap(1, new_index).
*/
static void
heap_up(cam_pinfo **queue_array, int new_index)
{
int child;
int parent;
child = new_index;
while (child != 1) {
parent = child >> 1;
if (queue_cmp(queue_array, parent, child) <= 0)
break;
swap(queue_array, parent, child);
child = parent;
}
}
/*
* heap_down: Given an array of cam_pinfo* elements with the
* Heap(index + 1, num_entries) property with index containing
* an unsorted entry, output Heap(index, num_entries).
*/
static void
heap_down(cam_pinfo **queue_array, int index, int num_entries)
{
int child;
int parent;
parent = index;
child = parent << 1;
for (; child <= num_entries; child = parent << 1) {
if (child < num_entries) {
/* child+1 is the right child of parent */
if (queue_cmp(queue_array, child + 1, child) < 0)
child++;
}
/* child is now the least child of parent */
if (queue_cmp(queue_array, parent, child) <= 0)
break;
swap(queue_array, child, parent);
parent = child;
}
}
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