2 * CAM request queue management functions.
4 * SPDX-License-Identifier: BSD-2-Clause
6 * Copyright (c) 1997 Justin T. Gibbs.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions, and the following disclaimer,
14 * without modification, immediately at the beginning of the file.
15 * 2. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 #include <sys/cdefs.h>
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/types.h>
35 #include <sys/malloc.h>
36 #include <sys/kernel.h>
39 #include <cam/cam_ccb.h>
40 #include <cam/cam_queue.h>
41 #include <cam/cam_debug.h>
43 static MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers");
44 static MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers");
45 static MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers");
47 static void heap_up(cam_pinfo **queue_array, int new_index);
48 static void heap_down(cam_pinfo **queue_array, int index,
52 camq_init(struct camq *camq, int size)
54 bzero(camq, sizeof(*camq));
55 camq->array_size = size;
56 if (camq->array_size != 0) {
58 * Heap algorithms like everything numbered from 1, so
59 * allocate one more to account for 0 base.
61 camq->queue_array = malloc((size + 1) * sizeof(cam_pinfo*),
63 if (camq->queue_array == NULL) {
64 printf("camq_init: - cannot malloc array!\n");
72 * Free a camq structure. This should only be called if a controller
73 * driver fails somehow during its attach routine or is unloaded and has
74 * obtained a camq structure. The XPT should ensure that the queue
75 * is empty before calling this routine.
78 camq_fini(struct camq *queue)
80 if (queue->queue_array != NULL) {
81 free(queue->queue_array, M_CAMQ);
86 camq_resize(struct camq *queue, int new_size)
88 cam_pinfo **new_array;
90 KASSERT(new_size >= queue->entries, ("camq_resize: "
91 "New queue size can't accommodate queued entries (%d < %d).",
92 new_size, queue->entries));
93 new_array = malloc((new_size + 1) * sizeof(cam_pinfo *), M_CAMQ,
95 if (new_array == NULL) {
96 /* Couldn't satisfy request */
97 return (CAM_RESRC_UNAVAIL);
100 * Heap algorithms like everything numbered from 1, so
101 * remember that our pointer into the heap array is offset
104 if (queue->queue_array != NULL) {
105 bcopy(queue->queue_array, new_array,
106 (queue->entries + 1) * sizeof(cam_pinfo *));
107 free(queue->queue_array, M_CAMQ);
109 queue->queue_array = new_array;
110 queue->array_size = new_size;
111 return (CAM_REQ_CMP);
115 * camq_insert: Given an array of cam_pinfo* elememnts with
116 * the Heap(1, num_elements) property and array_size - num_elements >= 1,
117 * output Heap(1, num_elements+1) including new_entry in the array.
120 camq_insert(struct camq *queue, cam_pinfo *new_entry)
123 KASSERT(queue->entries < queue->array_size,
124 ("camq_insert: Attempt to insert into a full queue (%d >= %d)",
125 queue->entries, queue->array_size));
127 queue->queue_array[queue->entries] = new_entry;
128 new_entry->index = queue->entries;
129 if (queue->entries != 0)
130 heap_up(queue->queue_array, queue->entries);
134 * camq_remove: Given an array of cam_pinfo* elevements with the
135 * Heap(1, num_elements) property and an index such that 1 <= index <=
136 * num_elements, remove that entry and restore the Heap(1, num_elements-1)
140 camq_remove(struct camq *queue, int index)
142 cam_pinfo *removed_entry;
144 if (index <= 0 || index > queue->entries)
145 panic("%s: Attempt to remove out-of-bounds index %d "
146 "from queue %p of size %d", __func__, index, queue,
149 removed_entry = queue->queue_array[index];
150 if (queue->entries != index) {
151 queue->queue_array[index] = queue->queue_array[queue->entries];
152 queue->queue_array[index]->index = index;
153 heap_down(queue->queue_array, index, queue->entries - 1);
155 removed_entry->index = CAM_UNQUEUED_INDEX;
157 return (removed_entry);
161 * camq_change_priority: Given an array of cam_pinfo* elements with the
162 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
163 * and a new priority for the element at index, change the priority of
164 * element index and restore the Heap(0, num_elements) property.
167 camq_change_priority(struct camq *queue, int index, uint32_t new_priority)
169 if (new_priority > queue->queue_array[index]->priority) {
170 queue->queue_array[index]->priority = new_priority;
171 heap_down(queue->queue_array, index, queue->entries);
173 /* new_priority <= old_priority */
174 queue->queue_array[index]->priority = new_priority;
175 heap_up(queue->queue_array, index);
180 cam_devq_alloc(int devices, int openings)
182 struct cam_devq *devq;
184 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT);
186 printf("cam_devq_alloc: - cannot malloc!\n");
189 if (cam_devq_init(devq, devices, openings) != 0) {
190 free(devq, M_CAMDEVQ);
197 cam_devq_init(struct cam_devq *devq, int devices, int openings)
200 bzero(devq, sizeof(*devq));
201 mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF);
202 if (camq_init(&devq->send_queue, devices) != 0)
204 devq->send_openings = openings;
205 devq->send_active = 0;
210 cam_devq_free(struct cam_devq *devq)
213 camq_fini(&devq->send_queue);
214 mtx_destroy(&devq->send_mtx);
215 free(devq, M_CAMDEVQ);
219 cam_devq_resize(struct cam_devq *camq, int devices)
223 retval = camq_resize(&camq->send_queue, devices);
228 cam_ccbq_alloc(int openings)
230 struct cam_ccbq *ccbq;
232 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT);
234 printf("cam_ccbq_alloc: - cannot malloc!\n");
237 if (cam_ccbq_init(ccbq, openings) != 0) {
238 free(ccbq, M_CAMCCBQ);
246 cam_ccbq_free(struct cam_ccbq *ccbq)
250 free(ccbq, M_CAMCCBQ);
255 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
259 delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
260 ccbq->total_openings += delta;
261 ccbq->dev_openings += delta;
263 new_size = imax(64, 1 << fls(new_size + new_size / 2));
264 if (new_size > ccbq->queue.array_size)
265 return (camq_resize(&ccbq->queue, new_size));
267 return (CAM_REQ_CMP);
271 cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
273 bzero(ccbq, sizeof(*ccbq));
274 if (camq_init(&ccbq->queue,
275 imax(64, 1 << fls(openings + openings / 2))) != 0)
277 ccbq->total_openings = openings;
278 ccbq->dev_openings = openings;
283 cam_ccbq_fini(struct cam_ccbq *ccbq)
286 camq_fini(&ccbq->queue);
290 * Heap routines for manipulating CAM queues.
293 * queue_cmp: Given an array of cam_pinfo* elements and indexes i
294 * and j, return less than 0, 0, or greater than 0 if i is less than,
295 * equal too, or greater than j respectively.
298 queue_cmp(cam_pinfo **queue_array, int i, int j)
300 if (queue_array[i]->priority == queue_array[j]->priority)
301 return ( queue_array[i]->generation
302 - queue_array[j]->generation );
304 return ( queue_array[i]->priority
305 - queue_array[j]->priority );
309 * swap: Given an array of cam_pinfo* elements and indexes i and j,
310 * exchange elements i and j.
313 swap(cam_pinfo **queue_array, int i, int j)
315 cam_pinfo *temp_qentry;
317 temp_qentry = queue_array[j];
318 queue_array[j] = queue_array[i];
319 queue_array[i] = temp_qentry;
320 queue_array[j]->index = j;
321 queue_array[i]->index = i;
325 * heap_up: Given an array of cam_pinfo* elements with the
326 * Heap(1, new_index-1) property and a new element in location
327 * new_index, output Heap(1, new_index).
330 heap_up(cam_pinfo **queue_array, int new_index)
339 if (queue_cmp(queue_array, parent, child) <= 0)
341 swap(queue_array, parent, child);
347 * heap_down: Given an array of cam_pinfo* elements with the
348 * Heap(index + 1, num_entries) property with index containing
349 * an unsorted entry, output Heap(index, num_entries).
352 heap_down(cam_pinfo **queue_array, int index, int num_entries)
359 for (; child <= num_entries; child = parent << 1) {
360 if (child < num_entries) {
361 /* child+1 is the right child of parent */
362 if (queue_cmp(queue_array, child + 1, child) < 0)
365 /* child is now the least child of parent */
366 if (queue_cmp(queue_array, parent, child) <= 0)
368 swap(queue_array, child, parent);