The cam_sim structure was being deallocated unconditionally by device
[dragonfly.git] / sys / bus / cam / cam_queue.c
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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 * $FreeBSD: src/sys/cam/cam_queue.c,v 1.5 1999/08/28 00:40:41 peter Exp $
3aed1355 29 * $DragonFly: src/sys/bus/cam/cam_queue.c,v 1.5 2004/03/15 01:10:30 dillon Exp $
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30 */
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/types.h>
34#include <sys/malloc.h>
35
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36#include "cam.h"
37#include "cam_ccb.h"
38#include "cam_queue.h"
39#include "cam_debug.h"
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40
41static __inline int
42 queue_cmp(cam_pinfo **queue_array, int i, int j);
43static __inline void
44 swap(cam_pinfo **queue_array, int i, int j);
45static void heap_up(cam_pinfo **queue_array, int new_index);
46static void heap_down(cam_pinfo **queue_array, int index,
47 int last_index);
48
49struct camq *
50camq_alloc(int size)
51{
52 struct camq *camq;
53
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54 camq = malloc(sizeof(*camq), M_DEVBUF, M_INTWAIT);
55 camq_init(camq, size);
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56 return (camq);
57}
58
59int
60camq_init(struct camq *camq, int size)
61{
62 bzero(camq, sizeof(*camq));
63 camq->array_size = size;
64 if (camq->array_size != 0) {
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65 camq->queue_array = malloc(size * sizeof(cam_pinfo *),
66 M_DEVBUF, M_INTWAIT);
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67 /*
68 * Heap algorithms like everything numbered from 1, so
69 * offset our pointer into the heap array by one element.
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70 *
71 * XXX this is a really dumb idea.
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72 */
73 camq->queue_array--;
74 }
75 return (0);
76}
77
78/*
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.
83 */
84void
85camq_free(struct camq *queue)
86{
87 if (queue != NULL) {
88 camq_fini(queue);
89 free(queue, M_DEVBUF);
90 }
91}
92
93void
94camq_fini(struct camq *queue)
95{
96 if (queue->queue_array != NULL) {
97 /*
98 * Heap algorithms like everything numbered from 1, so
99 * our pointer into the heap array is offset by one element.
100 */
101 queue->queue_array++;
102 free(queue->queue_array, M_DEVBUF);
103 }
104}
105
106u_int32_t
107camq_resize(struct camq *queue, int new_size)
108{
109 cam_pinfo **new_array;
110
111#ifdef DIAGNOSTIC
112 if (new_size < queue->entries)
113 panic("camq_resize: New queue size can't accomodate "
114 "queued entries.");
115#endif
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116 new_array = malloc(new_size * sizeof(cam_pinfo *), M_DEVBUF, M_INTWAIT);
117
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118 /*
119 * Heap algorithms like everything numbered from 1, so
120 * remember that our pointer into the heap array is offset
121 * by one element.
122 */
123 if (queue->queue_array != NULL) {
124 queue->queue_array++;
125 bcopy(queue->queue_array, new_array,
126 queue->entries * sizeof(cam_pinfo *));
127 free(queue->queue_array, M_DEVBUF);
128 }
129 queue->queue_array = new_array-1;
130 queue->array_size = new_size;
131 return (CAM_REQ_CMP);
132}
133
134/*
135 * camq_insert: Given an array of cam_pinfo* elememnts with
136 * the Heap(1, num_elements) property and array_size - num_elements >= 1,
137 * output Heap(1, num_elements+1) including new_entry in the array.
138 */
139void
140camq_insert(struct camq *queue, cam_pinfo *new_entry)
141{
142#ifdef DIAGNOSTIC
143 if (queue->entries >= queue->array_size)
144 panic("camq_insert: Attempt to insert into a full queue");
145#endif
146 queue->entries++;
147 queue->queue_array[queue->entries] = new_entry;
148 new_entry->index = queue->entries;
149 if (queue->entries != 0)
150 heap_up(queue->queue_array, queue->entries);
151}
152
153/*
154 * camq_remove: Given an array of cam_pinfo* elevements with the
155 * Heap(1, num_elements) property and an index such that 1 <= index <=
156 * num_elements, remove that entry and restore the Heap(1, num_elements-1)
157 * property.
158 */
159cam_pinfo *
160camq_remove(struct camq *queue, int index)
161{
162 cam_pinfo *removed_entry;
163
164 if (index == 0 || index > queue->entries)
165 return (NULL);
166 removed_entry = queue->queue_array[index];
167 if (queue->entries != index) {
168 queue->queue_array[index] = queue->queue_array[queue->entries];
169 queue->queue_array[index]->index = index;
170 heap_down(queue->queue_array, index, queue->entries - 1);
171 }
172 removed_entry->index = CAM_UNQUEUED_INDEX;
173 queue->entries--;
174 return (removed_entry);
175}
176
177/*
178 * camq_change_priority: Given an array of cam_pinfo* elements with the
179 * Heap(1, num_entries) property, an index such that 1 <= index <= num_elements,
180 * and an new priority for the element at index, change the priority of
181 * element index and restore the Heap(0, num_elements) property.
182 */
183void
184camq_change_priority(struct camq *queue, int index, u_int32_t new_priority)
185{
186 if (new_priority > queue->queue_array[index]->priority) {
187 queue->queue_array[index]->priority = new_priority;
188 heap_down(queue->queue_array, index, queue->entries);
189 } else {
190 /* new_priority <= old_priority */
191 queue->queue_array[index]->priority = new_priority;
192 heap_up(queue->queue_array, index);
193 }
194}
195
196struct cam_devq *
197cam_devq_alloc(int devices, int openings)
198{
199 struct cam_devq *devq;
200
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201 devq = malloc(sizeof(*devq), M_DEVBUF, M_INTWAIT);
202 cam_devq_init(devq, devices, openings);
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203 return (devq);
204}
205
206int
207cam_devq_init(struct cam_devq *devq, int devices, int openings)
208{
209 bzero(devq, sizeof(*devq));
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210 camq_init(&devq->alloc_queue, devices);
211 camq_init(&devq->send_queue, devices);
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212 devq->alloc_openings = openings;
213 devq->alloc_active = 0;
214 devq->send_openings = openings;
215 devq->send_active = 0;
3aed1355 216 devq->refcount = 1;
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217 return (0);
218}
219
220void
3aed1355 221cam_devq_reference(struct cam_devq *devq)
984263bc 222{
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223 ++devq->refcount;
224}
225
226void
227cam_devq_release(struct cam_devq *devq)
228{
229 if (--devq->refcount == 0) {
230 camq_fini(&devq->alloc_queue);
231 camq_fini(&devq->send_queue);
232 free(devq, M_DEVBUF);
233 }
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234}
235
236u_int32_t
237cam_devq_resize(struct cam_devq *camq, int devices)
238{
239 u_int32_t retval;
240
241 retval = camq_resize(&camq->alloc_queue, devices);
242
243 if (retval == CAM_REQ_CMP)
244 retval = camq_resize(&camq->send_queue, devices);
245
246 return (retval);
247}
248
249struct cam_ccbq *
250cam_ccbq_alloc(int openings)
251{
252 struct cam_ccbq *ccbq;
253
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254 ccbq = malloc(sizeof(*ccbq), M_DEVBUF, M_INTWAIT);
255 cam_ccbq_init(ccbq, openings);
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256 return (ccbq);
257}
258
259void
260cam_ccbq_free(struct cam_ccbq *ccbq)
261{
262 if (ccbq) {
263 camq_fini(&ccbq->queue);
264 free(ccbq, M_DEVBUF);
265 }
266}
267
268u_int32_t
269cam_ccbq_resize(struct cam_ccbq *ccbq, int new_size)
270{
271 int delta;
272 int space_left;
273
274 delta = new_size - (ccbq->dev_active + ccbq->dev_openings);
275 space_left = new_size
276 - ccbq->queue.entries
277 - ccbq->held
278 - ccbq->dev_active;
279
280 /*
281 * Only attempt to change the underlying queue size if we are
282 * shrinking it and there is space for all outstanding entries
283 * in the new array or we have been requested to grow the array.
284 * We don't fail in the case where we can't reduce the array size,
285 * but clients that care that the queue be "garbage collected"
286 * should detect this condition and call us again with the
287 * same size once the outstanding entries have been processed.
288 */
289 if (space_left < 0
290 || camq_resize(&ccbq->queue, new_size) == CAM_REQ_CMP) {
291 ccbq->devq_openings += delta;
292 ccbq->dev_openings += delta;
293 return (CAM_REQ_CMP);
294 } else {
295 return (CAM_RESRC_UNAVAIL);
296 }
297}
298
299int
300cam_ccbq_init(struct cam_ccbq *ccbq, int openings)
301{
302 bzero(ccbq, sizeof(*ccbq));
898d961b 303 camq_init(&ccbq->queue, openings);
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304 ccbq->devq_openings = openings;
305 ccbq->dev_openings = openings;
306 TAILQ_INIT(&ccbq->active_ccbs);
307 return (0);
308}
309
310/*
311 * Heap routines for manipulating CAM queues.
312 */
313/*
314 * queue_cmp: Given an array of cam_pinfo* elements and indexes i
315 * and j, return less than 0, 0, or greater than 0 if i is less than,
316 * equal too, or greater than j respectively.
317 */
318static __inline int
319queue_cmp(cam_pinfo **queue_array, int i, int j)
320{
321 if (queue_array[i]->priority == queue_array[j]->priority)
322 return ( queue_array[i]->generation
323 - queue_array[j]->generation );
324 else
325 return ( queue_array[i]->priority
326 - queue_array[j]->priority );
327}
328
329/*
330 * swap: Given an array of cam_pinfo* elements and indexes i and j,
331 * exchange elements i and j.
332 */
333static __inline void
334swap(cam_pinfo **queue_array, int i, int j)
335{
336 cam_pinfo *temp_qentry;
337
338 temp_qentry = queue_array[j];
339 queue_array[j] = queue_array[i];
340 queue_array[i] = temp_qentry;
341 queue_array[j]->index = j;
342 queue_array[i]->index = i;
343}
344
345/*
346 * heap_up: Given an array of cam_pinfo* elements with the
347 * Heap(1, new_index-1) property and a new element in location
348 * new_index, output Heap(1, new_index).
349 */
350static void
351heap_up(cam_pinfo **queue_array, int new_index)
352{
353 int child;
354 int parent;
355
356 child = new_index;
357
358 while (child != 1) {
359
360 parent = child >> 1;
361 if (queue_cmp(queue_array, parent, child) <= 0)
362 break;
363 swap(queue_array, parent, child);
364 child = parent;
365 }
366}
367
368/*
369 * heap_down: Given an array of cam_pinfo* elements with the
370 * Heap(index + 1, num_entries) property with index containing
371 * an unsorted entry, output Heap(index, num_entries).
372 */
373static void
374heap_down(cam_pinfo **queue_array, int index, int num_entries)
375{
376 int child;
377 int parent;
378
379 parent = index;
380 child = parent << 1;
381 for (; child <= num_entries; child = parent << 1) {
382
383 if (child < num_entries) {
384 /* child+1 is the right child of parent */
385 if (queue_cmp(queue_array, child + 1, child) < 0)
386 child++;
387 }
388 /* child is now the least child of parent */
389 if (queue_cmp(queue_array, parent, child) <= 0)
390 break;
391 swap(queue_array, child, parent);
392 parent = child;
393 }
394}