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) {
64 * Heap algorithms like everything numbered from 1, so
65 * allocate one more to account for 0 base.
67 camq->queue_array = malloc((size + 1) * sizeof(cam_pinfo*),
69 if (camq->queue_array == NULL) {
70 printf("camq_init: - cannot malloc array!\n");
78 * Free a camq structure. This should only be called if a controller
79 * driver failes somehow during its attach routine or is unloaded and has
80 * obtained a camq structure. The XPT should ensure that the queue
81 * is empty before calling this routine.
84 camq_fini(struct camq *queue)
86 if (queue->queue_array != NULL) {
87 free(queue->queue_array, M_CAMQ);
92 camq_resize(struct camq *queue, int new_size)
94 cam_pinfo **new_array;
96 KASSERT(new_size >= queue->entries, ("camq_resize: "
97 "New queue size can't accommodate queued entries (%d < %d).",
98 new_size, queue->entries));
99 new_array = malloc((new_size + 1) * sizeof(cam_pinfo *), M_CAMQ,
101 if (new_array == NULL) {
102 /* Couldn't satisfy request */
103 return (CAM_RESRC_UNAVAIL);
106 * Heap algorithms like everything numbered from 1, so
107 * remember that our pointer into the heap array is offset
110 if (queue->queue_array != NULL) {
111 bcopy(queue->queue_array, new_array,
112 (queue->entries + 1) * sizeof(cam_pinfo *));
113 free(queue->queue_array, M_CAMQ);
115 queue->queue_array = new_array;
116 queue->array_size = new_size;
117 return (CAM_REQ_CMP);
121 * camq_insert: Given an array of cam_pinfo* elememnts with
122 * the Heap(1, num_elements) property and array_size - num_elements >= 1,
123 * output Heap(1, num_elements+1) including new_entry in the array.
126 camq_insert(struct camq *queue, cam_pinfo *new_entry)
129 KASSERT(queue->entries < queue->array_size,
130 ("camq_insert: Attempt to insert into a full queue (%d >= %d)",
131 queue->entries, queue->array_size));
133 queue->queue_array[queue->entries] = new_entry;
134 new_entry->index = queue->entries;
135 if (queue->entries != 0)
136 heap_up(queue->queue_array, queue->entries);
140 * camq_remove: Given an array of cam_pinfo* elevements with the
141 * Heap(1, num_elements) property and an index such that 1 <= index <=
142 * num_elements, remove that entry and restore the Heap(1, num_elements-1)
146 camq_remove(struct camq *queue, int index)
148 cam_pinfo *removed_entry;
150 if (index <= 0 || index > queue->entries)
151 panic("%s: Attempt to remove out-of-bounds index %d "
152 "from queue %p of size %d", __func__, index, queue,
155 removed_entry = queue->queue_array[index];
156 if (queue->entries != index) {
157 queue->queue_array[index] = queue->queue_array[queue->entries];
158 queue->queue_array[index]->index = index;
159 heap_down(queue->queue_array, index, queue->entries - 1);
161 removed_entry->index = CAM_UNQUEUED_INDEX;
163 return (removed_entry);
167 * camq_change_priority: Given an array of cam_pinfo* elements with the
168 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
169 * and a new priority for the element at index, change the priority of
170 * element index and restore the Heap(0, num_elements) property.
173 camq_change_priority(struct camq *queue, int index, u_int32_t new_priority)
175 if (new_priority > queue->queue_array[index]->priority) {
176 queue->queue_array[index]->priority = new_priority;
177 heap_down(queue->queue_array, index, queue->entries);
179 /* new_priority <= old_priority */
180 queue->queue_array[index]->priority = new_priority;
181 heap_up(queue->queue_array, index);
186 cam_devq_alloc(int devices, int openings)
188 struct cam_devq *devq;
190 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT);
192 printf("cam_devq_alloc: - cannot malloc!\n");
195 if (cam_devq_init(devq, devices, openings) != 0) {
196 free(devq, M_CAMDEVQ);
203 cam_devq_init(struct cam_devq *devq, int devices, int openings)
206 bzero(devq, sizeof(*devq));
207 mtx_init(&devq->send_mtx, "CAM queue lock", NULL, MTX_DEF);
208 if (camq_init(&devq->send_queue, devices) != 0)
210 devq->send_openings = openings;
211 devq->send_active = 0;
216 cam_devq_free(struct cam_devq *devq)
219 camq_fini(&devq->send_queue);
220 mtx_destroy(&devq->send_mtx);
221 free(devq, M_CAMDEVQ);
225 cam_devq_resize(struct cam_devq *camq, int devices)
229 retval = camq_resize(&camq->send_queue, devices);
234 cam_ccbq_alloc(int openings)
236 struct cam_ccbq *ccbq;
238 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT);
240 printf("cam_ccbq_alloc: - cannot malloc!\n");
243 if (cam_ccbq_init(ccbq, openings) != 0) {
244 free(ccbq, M_CAMCCBQ);
252 cam_ccbq_free(struct cam_ccbq *ccbq)
256 free(ccbq, M_CAMCCBQ);
261 cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
265 delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
266 ccbq->total_openings += delta;
267 ccbq->dev_openings += delta;
269 new_size = imax(64, 1 << fls(new_size + new_size / 2));
270 if (new_size > ccbq->queue.array_size)
271 return (camq_resize(&ccbq->queue, new_size));
273 return (CAM_REQ_CMP);
277 cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
279 bzero(ccbq, sizeof(*ccbq));
280 if (camq_init(&ccbq->queue,
281 imax(64, 1 << fls(openings + openings / 2))) != 0)
283 ccbq->total_openings = openings;
284 ccbq->dev_openings = openings;
289 cam_ccbq_fini(struct cam_ccbq *ccbq)
292 camq_fini(&ccbq->queue);
296 * Heap routines for manipulating CAM queues.
299 * queue_cmp: Given an array of cam_pinfo* elements and indexes i
300 * and j, return less than 0, 0, or greater than 0 if i is less than,
301 * equal too, or greater than j respectively.
304 queue_cmp(cam_pinfo **queue_array, int i, int j)
306 if (queue_array[i]->priority == queue_array[j]->priority)
307 return ( queue_array[i]->generation
308 - queue_array[j]->generation );
310 return ( queue_array[i]->priority
311 - queue_array[j]->priority );
315 * swap: Given an array of cam_pinfo* elements and indexes i and j,
316 * exchange elements i and j.
319 swap(cam_pinfo **queue_array, int i, int j)
321 cam_pinfo *temp_qentry;
323 temp_qentry = queue_array[j];
324 queue_array[j] = queue_array[i];
325 queue_array[i] = temp_qentry;
326 queue_array[j]->index = j;
327 queue_array[i]->index = i;
331 * heap_up: Given an array of cam_pinfo* elements with the
332 * Heap(1, new_index-1) property and a new element in location
333 * new_index, output Heap(1, new_index).
336 heap_up(cam_pinfo **queue_array, int new_index)
345 if (queue_cmp(queue_array, parent, child) <= 0)
347 swap(queue_array, parent, child);
353 * heap_down: Given an array of cam_pinfo* elements with the
354 * Heap(index + 1, num_entries) property with index containing
355 * an unsorted entry, output Heap(index, num_entries).
358 heap_down(cam_pinfo **queue_array, int index, int num_entries)
365 for (; child <= num_entries; child = parent << 1) {
366 if (child < num_entries) {
367 /* child+1 is the right child of parent */
368 if (queue_cmp(queue_array, child + 1, child) < 0)
371 /* child is now the least child of parent */
372 if (queue_cmp(queue_array, parent, child) <= 0)
374 swap(queue_array, child, parent);