1/*-
2 * CAM request queue management functions.
3 *
4 * Copyright (c) 1997 Justin T. Gibbs.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer,
12 * without modification, immediately at the beginning of the file.
13 * 2. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
| 1/*-
2 * CAM request queue management functions.
3 *
4 * Copyright (c) 1997 Justin T. Gibbs.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer,
12 * without modification, immediately at the beginning of the file.
13 * 2. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
|
30__FBSDID("$FreeBSD: head/sys/cam/cam_queue.c 139743 2005-01-05 22:34:37Z imp $");
| 30__FBSDID("$FreeBSD: head/sys/cam/cam_queue.c 147723 2005-07-01 15:21:30Z avatar $");
|
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/types.h>
35#include <sys/malloc.h>
| 31
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>
|
36
37#include <cam/cam.h>
38#include <cam/cam_ccb.h>
39#include <cam/cam_queue.h>
40#include <cam/cam_debug.h>
41
| 37
38#include <cam/cam.h>
39#include <cam/cam_ccb.h>
40#include <cam/cam_queue.h>
41#include <cam/cam_debug.h>
42
|
| 43MALLOC_DEFINE(M_CAMQ, "CAM queue", "CAM queue buffers");
44MALLOC_DEFINE(M_CAMDEVQ, "CAM dev queue", "CAM dev queue buffers");
45MALLOC_DEFINE(M_CAMCCBQ, "CAM ccb queue", "CAM ccb queue buffers");
46
|
42static __inline int
43 queue_cmp(cam_pinfo **queue_array, int i, int j);
44static __inline void
45 swap(cam_pinfo **queue_array, int i, int j);
46static void heap_up(cam_pinfo **queue_array, int new_index);
47static void heap_down(cam_pinfo **queue_array, int index,
48 int last_index);
49
50struct camq *
51camq_alloc(int size)
52{
53 struct camq *camq;
54
| 47static __inline int
48 queue_cmp(cam_pinfo **queue_array, int i, int j);
49static __inline void
50 swap(cam_pinfo **queue_array, int i, int j);
51static void heap_up(cam_pinfo **queue_array, int new_index);
52static void heap_down(cam_pinfo **queue_array, int index,
53 int last_index);
54
55struct camq *
56camq_alloc(int size)
57{
58 struct camq *camq;
59
|
55 camq = (struct camq *)malloc(sizeof(*camq), M_DEVBUF, M_NOWAIT);
| 60 camq = (struct camq *)malloc(sizeof(*camq), M_CAMQ, M_NOWAIT);
|
56 if (camq != NULL) {
57 if (camq_init(camq, size) != 0) {
| 61 if (camq != NULL) {
62 if (camq_init(camq, size) != 0) {
|
58 free(camq, M_DEVBUF);
| 63 free(camq, M_CAMQ);
|
59 camq = NULL;
60 }
61 }
62 return (camq);
63}
64
65int
66camq_init(struct camq *camq, int size)
67{
68 bzero(camq, sizeof(*camq));
69 camq->array_size = size;
70 if (camq->array_size != 0) {
71 camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*),
| 64 camq = NULL;
65 }
66 }
67 return (camq);
68}
69
70int
71camq_init(struct camq *camq, int size)
72{
73 bzero(camq, sizeof(*camq));
74 camq->array_size = size;
75 if (camq->array_size != 0) {
76 camq->queue_array = (cam_pinfo**)malloc(size*sizeof(cam_pinfo*),
|
72 M_DEVBUF, M_NOWAIT);
| 77 M_CAMQ, M_NOWAIT);
|
73 if (camq->queue_array == NULL) {
74 printf("camq_init: - cannot malloc array!\n");
75 return (1);
76 }
77 /*
78 * Heap algorithms like everything numbered from 1, so
79 * offset our pointer into the heap array by one element.
80 */
81 camq->queue_array--;
82 }
83 return (0);
84}
85
86/*
87 * Free a camq structure. This should only be called if a controller
88 * driver failes somehow during its attach routine or is unloaded and has
89 * obtained a camq structure. The XPT should ensure that the queue
90 * is empty before calling this routine.
91 */
92void
93camq_free(struct camq *queue)
94{
95 if (queue != NULL) {
96 camq_fini(queue);
| 78 if (camq->queue_array == NULL) {
79 printf("camq_init: - cannot malloc array!\n");
80 return (1);
81 }
82 /*
83 * Heap algorithms like everything numbered from 1, so
84 * offset our pointer into the heap array by one element.
85 */
86 camq->queue_array--;
87 }
88 return (0);
89}
90
91/*
92 * Free a camq structure. This should only be called if a controller
93 * driver failes somehow during its attach routine or is unloaded and has
94 * obtained a camq structure. The XPT should ensure that the queue
95 * is empty before calling this routine.
96 */
97void
98camq_free(struct camq *queue)
99{
100 if (queue != NULL) {
101 camq_fini(queue);
|
97 free(queue, M_DEVBUF);
| 102 free(queue, M_CAMQ);
|
98 }
99}
100
101void
102camq_fini(struct camq *queue)
103{
104 if (queue->queue_array != NULL) {
105 /*
106 * Heap algorithms like everything numbered from 1, so
107 * our pointer into the heap array is offset by one element.
108 */
109 queue->queue_array++;
| 103 }
104}
105
106void
107camq_fini(struct camq *queue)
108{
109 if (queue->queue_array != NULL) {
110 /*
111 * Heap algorithms like everything numbered from 1, so
112 * our pointer into the heap array is offset by one element.
113 */
114 queue->queue_array++;
|
110 free(queue->queue_array, M_DEVBUF);
| 115 free(queue->queue_array, M_CAMQ);
|
111 }
112}
113
114u_int32_t
115camq_resize(struct camq *queue, int new_size)
116{
117 cam_pinfo **new_array;
118
119#ifdef DIAGNOSTIC
120 if (new_size < queue->entries)
121 panic("camq_resize: New queue size can't accomodate "
122 "queued entries.");
123#endif
124 new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *),
| 116 }
117}
118
119u_int32_t
120camq_resize(struct camq *queue, int new_size)
121{
122 cam_pinfo **new_array;
123
124#ifdef DIAGNOSTIC
125 if (new_size < queue->entries)
126 panic("camq_resize: New queue size can't accomodate "
127 "queued entries.");
128#endif
129 new_array = (cam_pinfo **)malloc(new_size * sizeof(cam_pinfo *),
|
125 M_DEVBUF, M_NOWAIT);
| 130 M_CAMQ, M_NOWAIT);
|
126 if (new_array == NULL) {
127 /* Couldn't satisfy request */
128 return (CAM_RESRC_UNAVAIL);
129 }
130 /*
131 * Heap algorithms like everything numbered from 1, so
132 * remember that our pointer into the heap array is offset
133 * by one element.
134 */
135 if (queue->queue_array != NULL) {
136 queue->queue_array++;
137 bcopy(queue->queue_array, new_array,
138 queue->entries * sizeof(cam_pinfo *));
| 131 if (new_array == NULL) {
132 /* Couldn't satisfy request */
133 return (CAM_RESRC_UNAVAIL);
134 }
135 /*
136 * Heap algorithms like everything numbered from 1, so
137 * remember that our pointer into the heap array is offset
138 * by one element.
139 */
140 if (queue->queue_array != NULL) {
141 queue->queue_array++;
142 bcopy(queue->queue_array, new_array,
143 queue->entries * sizeof(cam_pinfo *));
|
139 free(queue->queue_array, M_DEVBUF);
| 144 free(queue->queue_array, M_CAMQ);
|
140 }
141 queue->queue_array = new_array-1;
142 queue->array_size = new_size;
143 return (CAM_REQ_CMP);
144}
145
146/*
147 * camq_insert: Given an array of cam_pinfo* elememnts with
148 * the Heap(1, num_elements) property and array_size - num_elements >= 1,
149 * output Heap(1, num_elements+1) including new_entry in the array.
150 */
151void
152camq_insert(struct camq *queue, cam_pinfo *new_entry)
153{
154#ifdef DIAGNOSTIC
155 if (queue->entries >= queue->array_size)
156 panic("camq_insert: Attempt to insert into a full queue");
157#endif
158 queue->entries++;
159 queue->queue_array[queue->entries] = new_entry;
160 new_entry->index = queue->entries;
161 if (queue->entries != 0)
162 heap_up(queue->queue_array, queue->entries);
163}
164
165/*
166 * camq_remove: Given an array of cam_pinfo* elevements with the
167 * Heap(1, num_elements) property and an index such that 1 <= index <=
168 * num_elements, remove that entry and restore the Heap(1, num_elements-1)
169 * property.
170 */
171cam_pinfo *
172camq_remove(struct camq *queue, int index)
173{
174 cam_pinfo *removed_entry;
175
176 if (index == 0 || index > queue->entries)
177 return (NULL);
178 removed_entry = queue->queue_array[index];
179 if (queue->entries != index) {
180 queue->queue_array[index] = queue->queue_array[queue->entries];
181 queue->queue_array[index]->index = index;
182 heap_down(queue->queue_array, index, queue->entries - 1);
183 }
184 removed_entry->index = CAM_UNQUEUED_INDEX;
185 queue->entries--;
186 return (removed_entry);
187}
188
189/*
190 * camq_change_priority: Given an array of cam_pinfo* elements with the
191 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
192 * and a new priority for the element at index, change the priority of
193 * element index and restore the Heap(0, num_elements) property.
194 */
195void
196camq_change_priority(struct camq *queue, int index, u_int32_t new_priority)
197{
198 if (new_priority > queue->queue_array[index]->priority) {
199 queue->queue_array[index]->priority = new_priority;
200 heap_down(queue->queue_array, index, queue->entries);
201 } else {
202 /* new_priority <= old_priority */
203 queue->queue_array[index]->priority = new_priority;
204 heap_up(queue->queue_array, index);
205 }
206}
207
208struct cam_devq *
209cam_devq_alloc(int devices, int openings)
210{
211 struct cam_devq *devq;
212
| 145 }
146 queue->queue_array = new_array-1;
147 queue->array_size = new_size;
148 return (CAM_REQ_CMP);
149}
150
151/*
152 * camq_insert: Given an array of cam_pinfo* elememnts with
153 * the Heap(1, num_elements) property and array_size - num_elements >= 1,
154 * output Heap(1, num_elements+1) including new_entry in the array.
155 */
156void
157camq_insert(struct camq *queue, cam_pinfo *new_entry)
158{
159#ifdef DIAGNOSTIC
160 if (queue->entries >= queue->array_size)
161 panic("camq_insert: Attempt to insert into a full queue");
162#endif
163 queue->entries++;
164 queue->queue_array[queue->entries] = new_entry;
165 new_entry->index = queue->entries;
166 if (queue->entries != 0)
167 heap_up(queue->queue_array, queue->entries);
168}
169
170/*
171 * camq_remove: Given an array of cam_pinfo* elevements with the
172 * Heap(1, num_elements) property and an index such that 1 <= index <=
173 * num_elements, remove that entry and restore the Heap(1, num_elements-1)
174 * property.
175 */
176cam_pinfo *
177camq_remove(struct camq *queue, int index)
178{
179 cam_pinfo *removed_entry;
180
181 if (index == 0 || index > queue->entries)
182 return (NULL);
183 removed_entry = queue->queue_array[index];
184 if (queue->entries != index) {
185 queue->queue_array[index] = queue->queue_array[queue->entries];
186 queue->queue_array[index]->index = index;
187 heap_down(queue->queue_array, index, queue->entries - 1);
188 }
189 removed_entry->index = CAM_UNQUEUED_INDEX;
190 queue->entries--;
191 return (removed_entry);
192}
193
194/*
195 * camq_change_priority: Given an array of cam_pinfo* elements with the
196 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
197 * and a new priority for the element at index, change the priority of
198 * element index and restore the Heap(0, num_elements) property.
199 */
200void
201camq_change_priority(struct camq *queue, int index, u_int32_t new_priority)
202{
203 if (new_priority > queue->queue_array[index]->priority) {
204 queue->queue_array[index]->priority = new_priority;
205 heap_down(queue->queue_array, index, queue->entries);
206 } else {
207 /* new_priority <= old_priority */
208 queue->queue_array[index]->priority = new_priority;
209 heap_up(queue->queue_array, index);
210 }
211}
212
213struct cam_devq *
214cam_devq_alloc(int devices, int openings)
215{
216 struct cam_devq *devq;
217
|
213 devq = (struct cam_devq *)malloc(sizeof(*devq), M_DEVBUF, M_NOWAIT);
| 218 devq = (struct cam_devq *)malloc(sizeof(*devq), M_CAMDEVQ, M_NOWAIT);
|
214 if (devq == NULL) {
215 printf("cam_devq_alloc: - cannot malloc!\n");
216 return (NULL);
217 }
218 if (cam_devq_init(devq, devices, openings) != 0) {
| 219 if (devq == NULL) {
220 printf("cam_devq_alloc: - cannot malloc!\n");
221 return (NULL);
222 }
223 if (cam_devq_init(devq, devices, openings) != 0) {
|
219 free(devq, M_DEVBUF);
| 224 free(devq, M_CAMDEVQ);
|
220 return (NULL);
221 }
222
223 return (devq);
224}
225
226int
227cam_devq_init(struct cam_devq *devq, int devices, int openings)
228{
229 bzero(devq, sizeof(*devq));
230 if (camq_init(&devq->alloc_queue, devices) != 0) {
231 return (1);
232 }
233 if (camq_init(&devq->send_queue, devices) != 0) {
234 camq_fini(&devq->alloc_queue);
235 return (1);
236 }
237 devq->alloc_openings = openings;
238 devq->alloc_active = 0;
239 devq->send_openings = openings;
240 devq->send_active = 0;
241 return (0);
242}
243
244void
245cam_devq_free(struct cam_devq *devq)
246{
247 camq_fini(&devq->alloc_queue);
248 camq_fini(&devq->send_queue);
| 225 return (NULL);
226 }
227
228 return (devq);
229}
230
231int
232cam_devq_init(struct cam_devq *devq, int devices, int openings)
233{
234 bzero(devq, sizeof(*devq));
235 if (camq_init(&devq->alloc_queue, devices) != 0) {
236 return (1);
237 }
238 if (camq_init(&devq->send_queue, devices) != 0) {
239 camq_fini(&devq->alloc_queue);
240 return (1);
241 }
242 devq->alloc_openings = openings;
243 devq->alloc_active = 0;
244 devq->send_openings = openings;
245 devq->send_active = 0;
246 return (0);
247}
248
249void
250cam_devq_free(struct cam_devq *devq)
251{
252 camq_fini(&devq->alloc_queue);
253 camq_fini(&devq->send_queue);
|
249 free(devq, M_DEVBUF);
| 254 free(devq, M_CAMDEVQ);
|
250}
251
252u_int32_t
253cam_devq_resize(struct cam_devq *camq, int devices)
254{
255 u_int32_t retval;
256
257 retval = camq_resize(&camq->alloc_queue, devices);
258
259 if (retval == CAM_REQ_CMP)
260 retval = camq_resize(&camq->send_queue, devices);
261
262 return (retval);
263}
264
265struct cam_ccbq *
266cam_ccbq_alloc(int openings)
267{
268 struct cam_ccbq *ccbq;
269
| 255}
256
257u_int32_t
258cam_devq_resize(struct cam_devq *camq, int devices)
259{
260 u_int32_t retval;
261
262 retval = camq_resize(&camq->alloc_queue, devices);
263
264 if (retval == CAM_REQ_CMP)
265 retval = camq_resize(&camq->send_queue, devices);
266
267 return (retval);
268}
269
270struct cam_ccbq *
271cam_ccbq_alloc(int openings)
272{
273 struct cam_ccbq *ccbq;
274
|
270 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_DEVBUF, M_NOWAIT);
| 275 ccbq = (struct cam_ccbq *)malloc(sizeof(*ccbq), M_CAMCCBQ, M_NOWAIT);
|
271 if (ccbq == NULL) {
272 printf("cam_ccbq_alloc: - cannot malloc!\n");
273 return (NULL);
274 }
275 if (cam_ccbq_init(ccbq, openings) != 0) {
| 276 if (ccbq == NULL) {
277 printf("cam_ccbq_alloc: - cannot malloc!\n");
278 return (NULL);
279 }
280 if (cam_ccbq_init(ccbq, openings) != 0) {
|
276 free(ccbq, M_DEVBUF);
| 281 free(ccbq, M_CAMCCBQ);
|
277 return (NULL);
278 }
279
280 return (ccbq);
281}
282
283void
284cam_ccbq_free(struct cam_ccbq *ccbq)
285{
286 if (ccbq) {
287 camq_fini(&ccbq->queue);
| 282 return (NULL);
283 }
284
285 return (ccbq);
286}
287
288void
289cam_ccbq_free(struct cam_ccbq *ccbq)
290{
291 if (ccbq) {
292 camq_fini(&ccbq->queue);
|
288 free(ccbq, M_DEVBUF);
| 293 free(ccbq, M_CAMCCBQ);
|
289 }
290}
291
292u_int32_t
293cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
294{
295 int delta;
296 int space_left;
297
298 delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
299 space_left = new_size
300 - ccbq->queue.entries
301 - ccbq->held
302 - ccbq->dev_active;
303
304 /*
305 * Only attempt to change the underlying queue size if we are
306 * shrinking it and there is space for all outstanding entries
307 * in the new array or we have been requested to grow the array.
308 * We don't fail in the case where we can't reduce the array size,
309 * but clients that care that the queue be "garbage collected"
310 * should detect this condition and call us again with the
311 * same size once the outstanding entries have been processed.
312 */
313 if (space_left < 0
314 || camq_resize(&ccbq->queue, new_size) == CAM_REQ_CMP) {
315 ccbq->devq_openings += delta;
316 ccbq->dev_openings += delta;
317 return (CAM_REQ_CMP);
318 } else {
319 return (CAM_RESRC_UNAVAIL);
320 }
321}
322
323int
324cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
325{
326 bzero(ccbq, sizeof(*ccbq));
327 if (camq_init(&ccbq->queue, openings) != 0) {
328 return (1);
329 }
330 ccbq->devq_openings = openings;
331 ccbq->dev_openings = openings;
332 TAILQ_INIT(&ccbq->active_ccbs);
333 return (0);
334}
335
336/*
337 * Heap routines for manipulating CAM queues.
338 */
339/*
340 * queue_cmp: Given an array of cam_pinfo* elements and indexes i
341 * and j, return less than 0, 0, or greater than 0 if i is less than,
342 * equal too, or greater than j respectively.
343 */
344static __inline int
345queue_cmp(cam_pinfo **queue_array, int i, int j)
346{
347 if (queue_array[i]->priority == queue_array[j]->priority)
348 return ( queue_array[i]->generation
349 - queue_array[j]->generation );
350 else
351 return ( queue_array[i]->priority
352 - queue_array[j]->priority );
353}
354
355/*
356 * swap: Given an array of cam_pinfo* elements and indexes i and j,
357 * exchange elements i and j.
358 */
359static __inline void
360swap(cam_pinfo **queue_array, int i, int j)
361{
362 cam_pinfo *temp_qentry;
363
364 temp_qentry = queue_array[j];
365 queue_array[j] = queue_array[i];
366 queue_array[i] = temp_qentry;
367 queue_array[j]->index = j;
368 queue_array[i]->index = i;
369}
370
371/*
372 * heap_up: Given an array of cam_pinfo* elements with the
373 * Heap(1, new_index-1) property and a new element in location
374 * new_index, output Heap(1, new_index).
375 */
376static void
377heap_up(cam_pinfo **queue_array, int new_index)
378{
379 int child;
380 int parent;
381
382 child = new_index;
383
384 while (child != 1) {
385
386 parent = child >> 1;
387 if (queue_cmp(queue_array, parent, child) <= 0)
388 break;
389 swap(queue_array, parent, child);
390 child = parent;
391 }
392}
393
394/*
395 * heap_down: Given an array of cam_pinfo* elements with the
396 * Heap(index + 1, num_entries) property with index containing
397 * an unsorted entry, output Heap(index, num_entries).
398 */
399static void
400heap_down(cam_pinfo **queue_array, int index, int num_entries)
401{
402 int child;
403 int parent;
404
405 parent = index;
406 child = parent << 1;
407 for (; child <= num_entries; child = parent << 1) {
408
409 if (child < num_entries) {
410 /* child+1 is the right child of parent */
411 if (queue_cmp(queue_array, child + 1, child) < 0)
412 child++;
413 }
414 /* child is now the least child of parent */
415 if (queue_cmp(queue_array, parent, child) <= 0)
416 break;
417 swap(queue_array, child, parent);
418 parent = child;
419 }
420}
| 294 }
295}
296
297u_int32_t
298cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
299{
300 int delta;
301 int space_left;
302
303 delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
304 space_left = new_size
305 - ccbq->queue.entries
306 - ccbq->held
307 - ccbq->dev_active;
308
309 /*
310 * Only attempt to change the underlying queue size if we are
311 * shrinking it and there is space for all outstanding entries
312 * in the new array or we have been requested to grow the array.
313 * We don't fail in the case where we can't reduce the array size,
314 * but clients that care that the queue be "garbage collected"
315 * should detect this condition and call us again with the
316 * same size once the outstanding entries have been processed.
317 */
318 if (space_left < 0
319 || camq_resize(&ccbq->queue, new_size) == CAM_REQ_CMP) {
320 ccbq->devq_openings += delta;
321 ccbq->dev_openings += delta;
322 return (CAM_REQ_CMP);
323 } else {
324 return (CAM_RESRC_UNAVAIL);
325 }
326}
327
328int
329cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
330{
331 bzero(ccbq, sizeof(*ccbq));
332 if (camq_init(&ccbq->queue, openings) != 0) {
333 return (1);
334 }
335 ccbq->devq_openings = openings;
336 ccbq->dev_openings = openings;
337 TAILQ_INIT(&ccbq->active_ccbs);
338 return (0);
339}
340
341/*
342 * Heap routines for manipulating CAM queues.
343 */
344/*
345 * queue_cmp: Given an array of cam_pinfo* elements and indexes i
346 * and j, return less than 0, 0, or greater than 0 if i is less than,
347 * equal too, or greater than j respectively.
348 */
349static __inline int
350queue_cmp(cam_pinfo **queue_array, int i, int j)
351{
352 if (queue_array[i]->priority == queue_array[j]->priority)
353 return ( queue_array[i]->generation
354 - queue_array[j]->generation );
355 else
356 return ( queue_array[i]->priority
357 - queue_array[j]->priority );
358}
359
360/*
361 * swap: Given an array of cam_pinfo* elements and indexes i and j,
362 * exchange elements i and j.
363 */
364static __inline void
365swap(cam_pinfo **queue_array, int i, int j)
366{
367 cam_pinfo *temp_qentry;
368
369 temp_qentry = queue_array[j];
370 queue_array[j] = queue_array[i];
371 queue_array[i] = temp_qentry;
372 queue_array[j]->index = j;
373 queue_array[i]->index = i;
374}
375
376/*
377 * heap_up: Given an array of cam_pinfo* elements with the
378 * Heap(1, new_index-1) property and a new element in location
379 * new_index, output Heap(1, new_index).
380 */
381static void
382heap_up(cam_pinfo **queue_array, int new_index)
383{
384 int child;
385 int parent;
386
387 child = new_index;
388
389 while (child != 1) {
390
391 parent = child >> 1;
392 if (queue_cmp(queue_array, parent, child) <= 0)
393 break;
394 swap(queue_array, parent, child);
395 child = parent;
396 }
397}
398
399/*
400 * heap_down: Given an array of cam_pinfo* elements with the
401 * Heap(index + 1, num_entries) property with index containing
402 * an unsorted entry, output Heap(index, num_entries).
403 */
404static void
405heap_down(cam_pinfo **queue_array, int index, int num_entries)
406{
407 int child;
408 int parent;
409
410 parent = index;
411 child = parent << 1;
412 for (; child <= num_entries; child = parent << 1) {
413
414 if (child < num_entries) {
415 /* child+1 is the right child of parent */
416 if (queue_cmp(queue_array, child + 1, child) < 0)
417 child++;
418 }
419 /* child is now the least child of parent */
420 if (queue_cmp(queue_array, parent, child) <= 0)
421 break;
422 swap(queue_array, child, parent);
423 parent = child;
424 }
425}
|