2 * CAM request queue management functions.
4 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/types.h>
37 #include <sys/malloc.h>
38 #include <sys/kernel.h>
41 #include <cam/cam_ccb.h>
42 #include <cam/cam_queue.h>
43 #include <cam/cam_debug.h>
45 static MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers");
46 static MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers");
47 static MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers");
50 queue_cmp(cam_pinfo **queue_array, int i, int j);
52 swap(cam_pinfo **queue_array, int i, int j);
53 static void heap_up(cam_pinfo **queue_array, int new_index);
54 static void heap_down(cam_pinfo **queue_array, int index,
58 camq_init(struct camq *camq, int size)
60 bzero(camq, sizeof(*camq));
61 camq->array_size = size;
62 if (camq->array_size != 0) {
63 camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*),
65 if (camq->queue_array == NULL) {
66 printf("camq_init: - cannot malloc array!\n");
70 * Heap algorithms like everything numbered from 1, so
71 * offset our pointer into the heap array by one element.
79 * Free a camq structure. This should only be called if a controller
80 * driver failes somehow during its attach routine or is unloaded and has
81 * obtained a camq structure. The XPT should ensure that the queue
82 * is empty before calling this routine.
85 camq_fini(struct camq *queue)
87 if (queue->queue_array != NULL) {
89 * Heap algorithms like everything numbered from 1, so
90 * our pointer into the heap array is offset by one element.
93 free(queue->queue_array, M_CAMQ);
98 camq_resize(struct camq *queue, int new_size)
100 cam_pinfo **new_array;
102 KASSERT(new_size >= queue->entries, ("camq_resize: "
103 "New queue size can't accommodate queued entries (%d < %d).",
104 new_size, queue->entries));
105 new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *),
107 if (new_array == NULL) {
108 /* Couldn't satisfy request */
109 return (CAM_RESRC_UNAVAIL);
112 * Heap algorithms like everything numbered from 1, so
113 * remember that our pointer into the heap array is offset
116 if (queue->queue_array != NULL) {
117 queue->queue_array++;
118 bcopy(queue->queue_array, new_array,
119 queue->entries * sizeof(cam_pinfo *));
120 free(queue->queue_array, M_CAMQ);
122 queue->queue_array = new_array-1;
123 queue->array_size = new_size;
124 return (CAM_REQ_CMP);
128 * camq_insert: Given an array of cam_pinfo* elememnts with
129 * the Heap(1, num_elements) property and array_size - num_elements >= 1,
130 * output Heap(1, num_elements+1) including new_entry in the array.
133 camq_insert(struct camq *queue, cam_pinfo *new_entry)
136 KASSERT(queue->entries < queue->array_size,
137 ("camq_insert: Attempt to insert into a full queue (%d >= %d)",
138 queue->entries, queue->array_size));
140 queue->queue_array[queue->entries] = new_entry;
141 new_entry->index = queue->entries;
142 if (queue->entries != 0)
143 heap_up(queue->queue_array, queue->entries);
147 * camq_remove: Given an array of cam_pinfo* elevements with the
148 * Heap(1, num_elements) property and an index such that 1 <= index <=
149 * num_elements, remove that entry and restore the Heap(1, num_elements-1)
153 camq_remove(struct camq *queue, int index)
155 cam_pinfo *removed_entry;
157 if (index <= 0 || index > queue->entries)
158 panic("%s: Attempt to remove out-of-bounds index %d "
159 "from queue %p of size %d", __func__, index, queue,
162 removed_entry = queue->queue_array[index];
163 if (queue->entries != index) {
164 queue->queue_array[index] = queue->queue_array[queue->entries];
165 queue->queue_array[index]->index = index;
166 heap_down(queue->queue_array, index, queue->entries - 1);
168 removed_entry->index = CAM_UNQUEUED_INDEX;
170 return (removed_entry);
174 * camq_change_priority: Given an array of cam_pinfo* elements with the
175 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
176 * and a new priority for the element at index, change the priority of
177 * element index and restore the Heap(0, num_elements) property.
180 camq_change_priority(struct camq *queue, int index, u_int32_t new_priority)
182 if (new_priority > queue->queue_array[index]->priority) {
183 queue->queue_array[index]->priority = new_priority;
184 heap_down(queue->queue_array, index, queue->entries);
186 /* new_priority <= old_priority */
187 queue->queue_array[index]->priority = new_priority;
188 heap_up(queue->queue_array, index);
193 cam_devq_alloc(int devices, int openings)
195 struct cam_devq *devq;
197 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT);
199 printf("cam_devq_alloc: - cannot malloc!\n");
202 if (cam_devq_init(devq, devices, openings) != 0) {
203 free(devq, M_CAMDEVQ);
210 cam_devq_init(struct cam_devq *devq, int devices, int openings)
213 bzero(devq, sizeof(*devq));
214 mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF);
215 if (camq_init(&devq->send_queue, devices) != 0)
217 devq->send_openings = openings;
218 devq->send_active = 0;
223 cam_devq_free(struct cam_devq *devq)
226 camq_fini(&devq->send_queue);
227 mtx_destroy(&devq->send_mtx);
228 free(devq, M_CAMDEVQ);
232 cam_devq_resize(struct cam_devq *camq, int devices)
236 retval = camq_resize(&camq->send_queue, devices);
241 cam_ccbq_alloc(int openings)
243 struct cam_ccbq *ccbq;
245 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT);
247 printf("cam_ccbq_alloc: - cannot malloc!\n");
250 if (cam_ccbq_init(ccbq, openings) != 0) {
251 free(ccbq, M_CAMCCBQ);
259 cam_ccbq_free(struct cam_ccbq *ccbq)
263 free(ccbq, M_CAMCCBQ);
268 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
272 delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
273 ccbq->total_openings += delta;
274 ccbq->dev_openings += delta;
276 new_size = imax(64, 1 << fls(new_size + new_size / 2));
277 if (new_size > ccbq->queue.array_size)
278 return (camq_resize(&ccbq->queue, new_size));
280 return (CAM_REQ_CMP);
284 cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
286 bzero(ccbq, sizeof(*ccbq));
287 if (camq_init(&ccbq->queue,
288 imax(64, 1 << fls(openings + openings / 2))) != 0)
290 ccbq->total_openings = openings;
291 ccbq->dev_openings = openings;
296 cam_ccbq_fini(struct cam_ccbq *ccbq)
299 camq_fini(&ccbq->queue);
303 * Heap routines for manipulating CAM queues.
306 * queue_cmp: Given an array of cam_pinfo* elements and indexes i
307 * and j, return less than 0, 0, or greater than 0 if i is less than,
308 * equal too, or greater than j respectively.
311 queue_cmp(cam_pinfo **queue_array, int i, int j)
313 if (queue_array[i]->priority == queue_array[j]->priority)
314 return ( queue_array[i]->generation
315 - queue_array[j]->generation );
317 return ( queue_array[i]->priority
318 - queue_array[j]->priority );
322 * swap: Given an array of cam_pinfo* elements and indexes i and j,
323 * exchange elements i and j.
326 swap(cam_pinfo **queue_array, int i, int j)
328 cam_pinfo *temp_qentry;
330 temp_qentry = queue_array[j];
331 queue_array[j] = queue_array[i];
332 queue_array[i] = temp_qentry;
333 queue_array[j]->index = j;
334 queue_array[i]->index = i;
338 * heap_up: Given an array of cam_pinfo* elements with the
339 * Heap(1, new_index-1) property and a new element in location
340 * new_index, output Heap(1, new_index).
343 heap_up(cam_pinfo **queue_array, int new_index)
352 if (queue_cmp(queue_array, parent, child) <= 0)
354 swap(queue_array, parent, child);
360 * heap_down: Given an array of cam_pinfo* elements with the
361 * Heap(index + 1, num_entries) property with index containing
362 * an unsorted entry, output Heap(index, num_entries).
365 heap_down(cam_pinfo **queue_array, int index, int num_entries)
372 for (; child <= num_entries; child = parent << 1) {
373 if (child < num_entries) {
374 /* child+1 is the right child of parent */
375 if (queue_cmp(queue_array, child + 1, child) < 0)
378 /* child is now the least child of parent */
379 if (queue_cmp(queue_array, parent, child) <= 0)
381 swap(queue_array, child, parent);