1 | /* |
---|
2 | * Disk I/O buffering |
---|
3 | * Buffer managment |
---|
4 | * |
---|
5 | * Copyright (C) 2001 OKTET Ltd., St.-Peterburg, Russia |
---|
6 | * Author: Andrey G. Ivanov <Andrey.Ivanov@oktet.ru> |
---|
7 | * Victor V. Vengerov <vvv@oktet.ru> |
---|
8 | * Alexander Kukuta <kam@oktet.ru> |
---|
9 | * |
---|
10 | * @(#) bdbuf.c,v 1.14 2004/04/17 08:15:17 ralf Exp |
---|
11 | */ |
---|
12 | |
---|
13 | #if HAVE_CONFIG_H |
---|
14 | #include "config.h" |
---|
15 | #endif |
---|
16 | |
---|
17 | #define __RTEMS_VIOLATE_KERNEL_VISIBILITY__ |
---|
18 | #include <rtems.h> |
---|
19 | #include <limits.h> |
---|
20 | #include <errno.h> |
---|
21 | #include <assert.h> |
---|
22 | |
---|
23 | #include "rtems/bdbuf.h" |
---|
24 | |
---|
25 | /* Fatal errors: */ |
---|
26 | #define BLKDEV_FATAL_ERROR(n) (((uint32_t)'B' << 24) | ((uint32_t)(n) & (uint32_t)0x00FFFFFF)) |
---|
27 | #define BLKDEV_FATAL_BDBUF_CONSISTENCY BLKDEV_FATAL_ERROR(1) |
---|
28 | #define BLKDEV_FATAL_BDBUF_SWAPOUT BLKDEV_FATAL_ERROR(2) |
---|
29 | |
---|
30 | |
---|
31 | #define SWAPOUT_TASK_STACK_SIZE (RTEMS_MINIMUM_STACK_SIZE * 2) |
---|
32 | |
---|
33 | #define READ_MULTIPLE |
---|
34 | |
---|
35 | #if defined(READ_MULTIPLE) |
---|
36 | #define READ_AHEAD_MAX_BLK_CNT 32 |
---|
37 | typedef struct { |
---|
38 | blkdev_request req; |
---|
39 | blkdev_sg_buffer sg[READ_AHEAD_MAX_BLK_CNT]; |
---|
40 | } blkdev_request_read_ahead; |
---|
41 | /* |
---|
42 | * list of bd_bufs related to one transfer request |
---|
43 | */ |
---|
44 | typedef struct { |
---|
45 | int cnt; |
---|
46 | bdbuf_buffer *bd_bufs[READ_AHEAD_MAX_BLK_CNT]; |
---|
47 | } read_ahead_bd_buf_group; |
---|
48 | #endif |
---|
49 | |
---|
50 | typedef struct { |
---|
51 | blkdev_request *req; |
---|
52 | bdbuf_buffer **write_store; |
---|
53 | } write_tfer_done_arg_t; |
---|
54 | |
---|
55 | static rtems_task bdbuf_swapout_task(rtems_task_argument unused); |
---|
56 | |
---|
57 | static rtems_status_code bdbuf_release(bdbuf_buffer *bd_buf); |
---|
58 | /* |
---|
59 | * maximum number of blocks that might be chained together to one |
---|
60 | * write driver call |
---|
61 | */ |
---|
62 | #define SWAP_OUT_MAX_BLK_CNT 32 |
---|
63 | /*#define SWAP_OUT_MAX_BLK_CNT 1 */ |
---|
64 | /* |
---|
65 | * XXX: this is a global buffer. It is used in the swapout task |
---|
66 | * and currently will be reused only after it is no longer in use |
---|
67 | * |
---|
68 | */ |
---|
69 | static bdbuf_buffer *bd_buf_write_store[SWAP_OUT_MAX_BLK_CNT]; |
---|
70 | |
---|
71 | /* Block device request with a single buffer provided */ |
---|
72 | typedef struct blkdev_request1 { |
---|
73 | blkdev_request req; |
---|
74 | blkdev_sg_buffer sg[1]; |
---|
75 | } blkdev_request1; |
---|
76 | |
---|
77 | /* The context of buffering layer */ |
---|
78 | struct bdbuf_context rtems_bdbuf_ctx; |
---|
79 | |
---|
80 | #define SAFE |
---|
81 | #ifdef SAFE |
---|
82 | typedef rtems_mode preemption_key; |
---|
83 | |
---|
84 | #define DISABLE_PREEMPTION(key) \ |
---|
85 | do { \ |
---|
86 | rtems_task_mode(RTEMS_NO_PREEMPT, RTEMS_PREEMPT_MASK, &(key)); \ |
---|
87 | } while (0) |
---|
88 | |
---|
89 | #define ENABLE_PREEMPTION(key) \ |
---|
90 | do { \ |
---|
91 | rtems_mode temp; \ |
---|
92 | rtems_task_mode((key), RTEMS_PREEMPT_MASK, &temp); \ |
---|
93 | } while (0) |
---|
94 | |
---|
95 | #else |
---|
96 | |
---|
97 | typedef boolean preemption_key; |
---|
98 | |
---|
99 | #define DISABLE_PREEMPTION(key) \ |
---|
100 | do { \ |
---|
101 | (key) = _Thread_Executing->is_preemptible; \ |
---|
102 | _Thread_Executing->is_preemptible = 0; \ |
---|
103 | } while (0) |
---|
104 | |
---|
105 | #define ENABLE_PREEMPTION(key) \ |
---|
106 | do { \ |
---|
107 | _Thread_Executing->is_preemptible = (key); \ |
---|
108 | if (_Thread_Evaluate_mode()) \ |
---|
109 | _Thread_Dispatch(); \ |
---|
110 | } while (0) |
---|
111 | |
---|
112 | #endif |
---|
113 | |
---|
114 | |
---|
115 | /* The default maximum height of 32 allows for AVL trees having |
---|
116 | between 5,704,880 and 4,294,967,295 nodes, depending on order of |
---|
117 | insertion. You may change this compile-time constant as you |
---|
118 | wish. */ |
---|
119 | #ifndef AVL_MAX_HEIGHT |
---|
120 | #define AVL_MAX_HEIGHT 32 |
---|
121 | #endif |
---|
122 | |
---|
123 | /* |
---|
124 | * avl_search -- |
---|
125 | * Searches for the node with specified dev/block. |
---|
126 | * |
---|
127 | * PARAMETERS: |
---|
128 | * root - pointer to the root node of the AVL-Tree. |
---|
129 | * dev, block - search key |
---|
130 | * |
---|
131 | * RETURNS: |
---|
132 | * NULL if node with specified dev/block not found |
---|
133 | * non-NULL - pointer to the node with specified dev/block |
---|
134 | */ |
---|
135 | static bdbuf_buffer * |
---|
136 | avl_search(bdbuf_buffer **root, dev_t dev, blkdev_bnum block) |
---|
137 | { |
---|
138 | bdbuf_buffer *p = *root; |
---|
139 | |
---|
140 | while ((p != NULL) && ((p->dev != dev) || (p->block != block))) |
---|
141 | { |
---|
142 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
---|
143 | { |
---|
144 | p = p->avl.right; |
---|
145 | } |
---|
146 | else |
---|
147 | { |
---|
148 | p = p->avl.left; |
---|
149 | } |
---|
150 | } |
---|
151 | |
---|
152 | return p; |
---|
153 | } |
---|
154 | |
---|
155 | |
---|
156 | /* avl_search_for_sync -- |
---|
157 | * Search in AVL tree for first modified buffer belongs to specified |
---|
158 | * disk device. |
---|
159 | * |
---|
160 | * PARAMETERS: |
---|
161 | * root - pointer to tree root |
---|
162 | * dd - disk device descriptor |
---|
163 | * |
---|
164 | * RETURNS: |
---|
165 | * Block buffer, or NULL if no modified blocks on specified device |
---|
166 | * exists. |
---|
167 | */ |
---|
168 | static bdbuf_buffer * |
---|
169 | avl_search_for_sync(bdbuf_buffer **root, disk_device *dd) |
---|
170 | { |
---|
171 | dev_t dev = dd->phys_dev->dev; |
---|
172 | blkdev_bnum block_start = dd->start; |
---|
173 | blkdev_bnum block_end = dd->start + dd->size - 1; |
---|
174 | |
---|
175 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
---|
176 | bdbuf_buffer **buf_prev = buf_stack; |
---|
177 | bdbuf_buffer *p = *root; |
---|
178 | |
---|
179 | while (p != NULL) |
---|
180 | { |
---|
181 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block_start))) |
---|
182 | { |
---|
183 | p = p->avl.right; |
---|
184 | } |
---|
185 | else if ((p->dev > dev) || ((p->dev == dev) && (p->block > block_end))) |
---|
186 | { |
---|
187 | p = p->avl.left; |
---|
188 | } |
---|
189 | else if (p->modified) |
---|
190 | { |
---|
191 | return p; |
---|
192 | } |
---|
193 | else |
---|
194 | { |
---|
195 | if (p->avl.right != NULL) |
---|
196 | { |
---|
197 | *buf_prev++ = p->avl.right; |
---|
198 | } |
---|
199 | p = p->avl.left; |
---|
200 | } |
---|
201 | |
---|
202 | if ((p == NULL) && (buf_prev > buf_stack)) |
---|
203 | { |
---|
204 | p = *--buf_prev; |
---|
205 | } |
---|
206 | } |
---|
207 | |
---|
208 | return p; |
---|
209 | } |
---|
210 | |
---|
211 | |
---|
212 | /* |
---|
213 | * avl_insert -- |
---|
214 | * Inserts the specified node to the AVl-Tree. |
---|
215 | * |
---|
216 | * PARAMETERS: |
---|
217 | * root - Pointer to pointer to the root node |
---|
218 | * node - Pointer to the node to add. |
---|
219 | * |
---|
220 | * RETURNS: |
---|
221 | * 0 - The node added successfully |
---|
222 | * -1 - An error occured |
---|
223 | */ |
---|
224 | static int |
---|
225 | avl_insert(bdbuf_buffer **root, bdbuf_buffer *node) |
---|
226 | { |
---|
227 | dev_t dev = node->dev; |
---|
228 | blkdev_bnum block = node->block; |
---|
229 | |
---|
230 | bdbuf_buffer *p = *root; |
---|
231 | bdbuf_buffer *q, *p1, *p2; |
---|
232 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
---|
233 | bdbuf_buffer **buf_prev = buf_stack; |
---|
234 | |
---|
235 | boolean modified = FALSE; |
---|
236 | |
---|
237 | if (p == NULL) |
---|
238 | { |
---|
239 | *root = node; |
---|
240 | node->avl.left = NULL; |
---|
241 | node->avl.right = NULL; |
---|
242 | node->avl.bal = 0; |
---|
243 | return 0; |
---|
244 | } |
---|
245 | |
---|
246 | while (p != NULL) |
---|
247 | { |
---|
248 | *buf_prev++ = p; |
---|
249 | |
---|
250 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
---|
251 | { |
---|
252 | p->avl.cache = 1; |
---|
253 | q = p->avl.right; |
---|
254 | if (q == NULL) |
---|
255 | { |
---|
256 | q = node; |
---|
257 | p->avl.right = q = node; |
---|
258 | break; |
---|
259 | } |
---|
260 | } |
---|
261 | else if ((p->dev != dev) || (p->block != block)) |
---|
262 | { |
---|
263 | p->avl.cache = -1; |
---|
264 | q = p->avl.left; |
---|
265 | if (q == NULL) |
---|
266 | { |
---|
267 | q = node; |
---|
268 | p->avl.left = q; |
---|
269 | break; |
---|
270 | } |
---|
271 | } |
---|
272 | else |
---|
273 | { |
---|
274 | return -1; |
---|
275 | } |
---|
276 | |
---|
277 | p = q; |
---|
278 | } |
---|
279 | |
---|
280 | q->avl.left = q->avl.right = NULL; |
---|
281 | q->avl.bal = 0; |
---|
282 | modified = TRUE; |
---|
283 | buf_prev--; |
---|
284 | |
---|
285 | while (modified) |
---|
286 | { |
---|
287 | if (p->avl.cache == -1) |
---|
288 | { |
---|
289 | switch (p->avl.bal) |
---|
290 | { |
---|
291 | case 1: |
---|
292 | p->avl.bal = 0; |
---|
293 | modified = FALSE; |
---|
294 | break; |
---|
295 | |
---|
296 | case 0: |
---|
297 | p->avl.bal = -1; |
---|
298 | break; |
---|
299 | |
---|
300 | case -1: |
---|
301 | p1 = p->avl.left; |
---|
302 | if (p1->avl.bal == -1) /* simple LL-turn */ |
---|
303 | { |
---|
304 | p->avl.left = p1->avl.right; |
---|
305 | p1->avl.right = p; |
---|
306 | p->avl.bal = 0; |
---|
307 | p = p1; |
---|
308 | } |
---|
309 | else /* double LR-turn */ |
---|
310 | { |
---|
311 | p2 = p1->avl.right; |
---|
312 | p1->avl.right = p2->avl.left; |
---|
313 | p2->avl.left = p1; |
---|
314 | p->avl.left = p2->avl.right; |
---|
315 | p2->avl.right = p; |
---|
316 | if (p2->avl.bal == -1) p->avl.bal = +1; else p->avl.bal = 0; |
---|
317 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
318 | p = p2; |
---|
319 | } |
---|
320 | p->avl.bal = 0; |
---|
321 | modified = FALSE; |
---|
322 | break; |
---|
323 | |
---|
324 | default: |
---|
325 | break; |
---|
326 | } |
---|
327 | } |
---|
328 | else |
---|
329 | { |
---|
330 | switch (p->avl.bal) |
---|
331 | { |
---|
332 | case -1: |
---|
333 | p->avl.bal = 0; |
---|
334 | modified = FALSE; |
---|
335 | break; |
---|
336 | |
---|
337 | case 0: |
---|
338 | p->avl.bal = 1; |
---|
339 | break; |
---|
340 | |
---|
341 | case 1: |
---|
342 | p1 = p->avl.right; |
---|
343 | if (p1->avl.bal == 1) /* simple RR-turn */ |
---|
344 | { |
---|
345 | p->avl.right = p1->avl.left; |
---|
346 | p1->avl.left = p; |
---|
347 | p->avl.bal = 0; |
---|
348 | p = p1; |
---|
349 | } |
---|
350 | else /* double RL-turn */ |
---|
351 | { |
---|
352 | p2 = p1->avl.left; |
---|
353 | p1->avl.left = p2->avl.right; |
---|
354 | p2->avl.right = p1; |
---|
355 | p->avl.right = p2->avl.left; |
---|
356 | p2->avl.left = p; |
---|
357 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
358 | if (p2->avl.bal == -1) p1->avl.bal = +1; else p1->avl.bal = 0; |
---|
359 | p = p2; |
---|
360 | } |
---|
361 | p->avl.bal = 0; |
---|
362 | modified = FALSE; |
---|
363 | break; |
---|
364 | |
---|
365 | default: |
---|
366 | break; |
---|
367 | } |
---|
368 | } |
---|
369 | q = p; |
---|
370 | if (buf_prev > buf_stack) |
---|
371 | { |
---|
372 | p = *--buf_prev; |
---|
373 | |
---|
374 | if (p->avl.cache == -1) |
---|
375 | { |
---|
376 | p->avl.left = q; |
---|
377 | } |
---|
378 | else |
---|
379 | { |
---|
380 | p->avl.right = q; |
---|
381 | } |
---|
382 | } |
---|
383 | else |
---|
384 | { |
---|
385 | *root = p; |
---|
386 | break; |
---|
387 | } |
---|
388 | }; |
---|
389 | |
---|
390 | return 0; |
---|
391 | } |
---|
392 | |
---|
393 | |
---|
394 | /* avl_remove -- |
---|
395 | * removes the node from the tree. |
---|
396 | * |
---|
397 | * PARAMETERS: |
---|
398 | * root_addr - Pointer to pointer to the root node |
---|
399 | * node - Pointer to the node to remove |
---|
400 | * |
---|
401 | * RETURNS: |
---|
402 | * 0 - Item removed |
---|
403 | * -1 - No such item found |
---|
404 | */ |
---|
405 | static int |
---|
406 | avl_remove(bdbuf_buffer **root, const bdbuf_buffer *node) |
---|
407 | { |
---|
408 | dev_t dev = node->dev; |
---|
409 | blkdev_bnum block = node->block; |
---|
410 | |
---|
411 | bdbuf_buffer *p = *root; |
---|
412 | bdbuf_buffer *q, *r, *s, *p1, *p2; |
---|
413 | bdbuf_buffer *buf_stack[AVL_MAX_HEIGHT]; |
---|
414 | bdbuf_buffer **buf_prev = buf_stack; |
---|
415 | |
---|
416 | boolean modified = FALSE; |
---|
417 | |
---|
418 | memset(buf_stack, 0, sizeof(buf_stack)); |
---|
419 | |
---|
420 | while (p != NULL) |
---|
421 | { |
---|
422 | *buf_prev++ = p; |
---|
423 | |
---|
424 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
---|
425 | { |
---|
426 | p->avl.cache = 1; |
---|
427 | p = p->avl.right; |
---|
428 | } |
---|
429 | else if ((p->dev != dev) || (p->block != block)) |
---|
430 | { |
---|
431 | p->avl.cache = -1; |
---|
432 | p = p->avl.left; |
---|
433 | } |
---|
434 | else |
---|
435 | { |
---|
436 | /* node found */ |
---|
437 | break; |
---|
438 | } |
---|
439 | } |
---|
440 | |
---|
441 | if (p == NULL) |
---|
442 | { |
---|
443 | /* there is no such node */ |
---|
444 | return -1; |
---|
445 | } |
---|
446 | |
---|
447 | q = p; |
---|
448 | |
---|
449 | buf_prev--; |
---|
450 | if (buf_prev > buf_stack) |
---|
451 | { |
---|
452 | p = *(buf_prev - 1); |
---|
453 | } |
---|
454 | else |
---|
455 | { |
---|
456 | p = NULL; |
---|
457 | } |
---|
458 | |
---|
459 | /* at this moment q - is a node to delete, p is q's parent */ |
---|
460 | if (q->avl.right == NULL) |
---|
461 | { |
---|
462 | r = q->avl.left; |
---|
463 | if (r != NULL) |
---|
464 | { |
---|
465 | r->avl.bal = 0; |
---|
466 | } |
---|
467 | q = r; |
---|
468 | } |
---|
469 | else |
---|
470 | { |
---|
471 | bdbuf_buffer **t; |
---|
472 | |
---|
473 | r = q->avl.right; |
---|
474 | |
---|
475 | if (r->avl.left == NULL) |
---|
476 | { |
---|
477 | r->avl.left = q->avl.left; |
---|
478 | r->avl.bal = q->avl.bal; |
---|
479 | r->avl.cache = 1; |
---|
480 | *buf_prev++ = q = r; |
---|
481 | } |
---|
482 | else |
---|
483 | { |
---|
484 | t = buf_prev++; |
---|
485 | s = r; |
---|
486 | |
---|
487 | while (s->avl.left != NULL) |
---|
488 | { |
---|
489 | *buf_prev++ = r = s; |
---|
490 | s = r->avl.left; |
---|
491 | r->avl.cache = -1; |
---|
492 | } |
---|
493 | |
---|
494 | s->avl.left = q->avl.left; |
---|
495 | r->avl.left = s->avl.right; |
---|
496 | s->avl.right = q->avl.right; |
---|
497 | s->avl.bal = q->avl.bal; |
---|
498 | s->avl.cache = 1; |
---|
499 | |
---|
500 | *t = q = s; |
---|
501 | } |
---|
502 | } |
---|
503 | |
---|
504 | if (p != NULL) |
---|
505 | { |
---|
506 | if (p->avl.cache == -1) |
---|
507 | { |
---|
508 | p->avl.left = q; |
---|
509 | } |
---|
510 | else |
---|
511 | { |
---|
512 | p->avl.right = q; |
---|
513 | } |
---|
514 | } |
---|
515 | else |
---|
516 | { |
---|
517 | *root = q; |
---|
518 | } |
---|
519 | |
---|
520 | modified = TRUE; |
---|
521 | |
---|
522 | while (modified) |
---|
523 | { |
---|
524 | if (buf_prev > buf_stack) |
---|
525 | { |
---|
526 | p = *--buf_prev; |
---|
527 | } |
---|
528 | else |
---|
529 | { |
---|
530 | break; |
---|
531 | } |
---|
532 | |
---|
533 | if (p->avl.cache == -1) |
---|
534 | { |
---|
535 | /* rebalance left branch */ |
---|
536 | switch (p->avl.bal) |
---|
537 | { |
---|
538 | case -1: |
---|
539 | p->avl.bal = 0; |
---|
540 | break; |
---|
541 | case 0: |
---|
542 | p->avl.bal = 1; |
---|
543 | modified = FALSE; |
---|
544 | break; |
---|
545 | |
---|
546 | case +1: |
---|
547 | p1 = p->avl.right; |
---|
548 | |
---|
549 | if (p1->avl.bal >= 0) /* simple RR-turn */ |
---|
550 | { |
---|
551 | p->avl.right = p1->avl.left; |
---|
552 | p1->avl.left = p; |
---|
553 | |
---|
554 | if (p1->avl.bal == 0) |
---|
555 | { |
---|
556 | p1->avl.bal = -1; |
---|
557 | modified = FALSE; |
---|
558 | } |
---|
559 | else |
---|
560 | { |
---|
561 | p->avl.bal = 0; |
---|
562 | p1->avl.bal = 0; |
---|
563 | } |
---|
564 | p = p1; |
---|
565 | } |
---|
566 | else /* double RL-turn */ |
---|
567 | { |
---|
568 | p2 = p1->avl.left; |
---|
569 | |
---|
570 | p1->avl.left = p2->avl.right; |
---|
571 | p2->avl.right = p1; |
---|
572 | p->avl.right = p2->avl.left; |
---|
573 | p2->avl.left = p; |
---|
574 | |
---|
575 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
576 | if (p2->avl.bal == -1) p1->avl.bal = 1; else p1->avl.bal = 0; |
---|
577 | |
---|
578 | p = p2; |
---|
579 | p2->avl.bal = 0; |
---|
580 | } |
---|
581 | break; |
---|
582 | |
---|
583 | default: |
---|
584 | break; |
---|
585 | } |
---|
586 | } |
---|
587 | else |
---|
588 | { |
---|
589 | /* rebalance right branch */ |
---|
590 | switch (p->avl.bal) |
---|
591 | { |
---|
592 | case +1: |
---|
593 | p->avl.bal = 0; |
---|
594 | break; |
---|
595 | |
---|
596 | case 0: |
---|
597 | p->avl.bal = -1; |
---|
598 | modified = FALSE; |
---|
599 | break; |
---|
600 | |
---|
601 | case -1: |
---|
602 | p1 = p->avl.left; |
---|
603 | |
---|
604 | if (p1->avl.bal <= 0) /* simple LL-turn */ |
---|
605 | { |
---|
606 | p->avl.left = p1->avl.right; |
---|
607 | p1->avl.right = p; |
---|
608 | if (p1->avl.bal == 0) |
---|
609 | { |
---|
610 | p1->avl.bal = 1; |
---|
611 | modified = FALSE; |
---|
612 | } |
---|
613 | else |
---|
614 | { |
---|
615 | p->avl.bal = 0; |
---|
616 | p1->avl.bal = 0; |
---|
617 | } |
---|
618 | p = p1; |
---|
619 | } |
---|
620 | else /* double LR-turn */ |
---|
621 | { |
---|
622 | p2 = p1->avl.right; |
---|
623 | |
---|
624 | p1->avl.right = p2->avl.left; |
---|
625 | p2->avl.left = p1; |
---|
626 | p->avl.left = p2->avl.right; |
---|
627 | p2->avl.right = p; |
---|
628 | |
---|
629 | if (p2->avl.bal == -1) p->avl.bal = 1; else p->avl.bal = 0; |
---|
630 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
631 | |
---|
632 | p = p2; |
---|
633 | p2->avl.bal = 0; |
---|
634 | } |
---|
635 | break; |
---|
636 | |
---|
637 | default: |
---|
638 | break; |
---|
639 | } |
---|
640 | } |
---|
641 | |
---|
642 | if (buf_prev > buf_stack) |
---|
643 | { |
---|
644 | q = *(buf_prev - 1); |
---|
645 | |
---|
646 | if (q->avl.cache == -1) |
---|
647 | { |
---|
648 | q->avl.left = p; |
---|
649 | } |
---|
650 | else |
---|
651 | { |
---|
652 | q->avl.right = p; |
---|
653 | } |
---|
654 | } |
---|
655 | else |
---|
656 | { |
---|
657 | *root = p; |
---|
658 | break; |
---|
659 | } |
---|
660 | |
---|
661 | } |
---|
662 | |
---|
663 | return 0; |
---|
664 | } |
---|
665 | |
---|
666 | /* bdbuf_initialize_pool -- |
---|
667 | * Initialize single buffer pool. |
---|
668 | * |
---|
669 | * PARAMETERS: |
---|
670 | * config - buffer pool configuration |
---|
671 | * pool - pool number |
---|
672 | * |
---|
673 | * RETURNS: |
---|
674 | * RTEMS_SUCCESSFUL, if buffer pool initialized successfully, or error |
---|
675 | * code if error occured. |
---|
676 | */ |
---|
677 | static rtems_status_code |
---|
678 | bdbuf_initialize_pool(rtems_bdbuf_config *config, int pool) |
---|
679 | { |
---|
680 | bdbuf_pool *p = rtems_bdbuf_ctx.pool + pool; |
---|
681 | unsigned char *bufs; |
---|
682 | bdbuf_buffer *b; |
---|
683 | rtems_status_code rc; |
---|
684 | int i; |
---|
685 | |
---|
686 | p->blksize = config->size; |
---|
687 | p->nblks = config->num; |
---|
688 | p->tree = NULL; |
---|
689 | |
---|
690 | rtems_chain_initialize_empty(&p->free); |
---|
691 | rtems_chain_initialize_empty(&p->lru); |
---|
692 | |
---|
693 | /* Allocate memory for buffer descriptors */ |
---|
694 | p->bdbufs = calloc(config->num, sizeof(bdbuf_buffer)); |
---|
695 | if (p->bdbufs == NULL) |
---|
696 | { |
---|
697 | return RTEMS_NO_MEMORY; |
---|
698 | } |
---|
699 | |
---|
700 | /* Allocate memory for buffers if required */ |
---|
701 | if (config->mem_area == NULL) |
---|
702 | { |
---|
703 | bufs = p->mallocd_bufs = malloc(config->num * config->size); |
---|
704 | if (bufs == NULL) |
---|
705 | { |
---|
706 | free(p->bdbufs); |
---|
707 | return RTEMS_NO_MEMORY; |
---|
708 | } |
---|
709 | } |
---|
710 | else |
---|
711 | { |
---|
712 | bufs = config->mem_area; |
---|
713 | p->mallocd_bufs = NULL; |
---|
714 | } |
---|
715 | |
---|
716 | for (i = 0, b = p->bdbufs; i < p->nblks; i++, b++, bufs += p->blksize) |
---|
717 | { |
---|
718 | b->dev = -1; b->block = 0; |
---|
719 | b->buffer = bufs; |
---|
720 | b->actual = b->modified = b->in_progress = FALSE; |
---|
721 | b->use_count = 0; |
---|
722 | b->pool = pool; |
---|
723 | rtems_chain_append(&p->free, &b->link); |
---|
724 | } |
---|
725 | |
---|
726 | rc = rtems_semaphore_create( |
---|
727 | rtems_build_name('B', 'U', 'F', 'G'), |
---|
728 | p->nblks, |
---|
729 | RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | |
---|
730 | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, |
---|
731 | 0, |
---|
732 | &p->bufget_sema); |
---|
733 | |
---|
734 | if (rc != RTEMS_SUCCESSFUL) |
---|
735 | { |
---|
736 | free(p->bdbufs); |
---|
737 | free(p->mallocd_bufs); |
---|
738 | return rc; |
---|
739 | } |
---|
740 | |
---|
741 | return RTEMS_SUCCESSFUL; |
---|
742 | } |
---|
743 | |
---|
744 | /* bdbuf_release_pool -- |
---|
745 | * Free resources allocated for buffer pool with specified number. |
---|
746 | * |
---|
747 | * PARAMETERS: |
---|
748 | * pool - buffer pool number |
---|
749 | * |
---|
750 | * RETURNS: |
---|
751 | * RTEMS_SUCCESSFUL |
---|
752 | */ |
---|
753 | static rtems_status_code |
---|
754 | bdbuf_release_pool(rtems_bdpool_id pool) |
---|
755 | { |
---|
756 | bdbuf_pool *p = rtems_bdbuf_ctx.pool + pool; |
---|
757 | rtems_semaphore_delete(p->bufget_sema); |
---|
758 | free(p->bdbufs); |
---|
759 | free(p->mallocd_bufs); |
---|
760 | return RTEMS_SUCCESSFUL; |
---|
761 | } |
---|
762 | |
---|
763 | /* rtems_bdbuf_init -- |
---|
764 | * Prepare buffering layer to work - initialize buffer descritors |
---|
765 | * and (if it is neccessary)buffers. Buffers will be allocated accoriding |
---|
766 | * to the configuration table, each entry describes kind of block and |
---|
767 | * amount requested. After initialization all blocks is placed into |
---|
768 | * free elements lists. |
---|
769 | * |
---|
770 | * PARAMETERS: |
---|
771 | * conf_table - pointer to the buffers configuration table |
---|
772 | * size - number of entries in configuration table |
---|
773 | * |
---|
774 | * RETURNS: |
---|
775 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
776 | * or error code if error is occured) |
---|
777 | */ |
---|
778 | rtems_status_code |
---|
779 | rtems_bdbuf_init(rtems_bdbuf_config *conf_table, int size) |
---|
780 | { |
---|
781 | rtems_bdpool_id i; |
---|
782 | rtems_status_code rc; |
---|
783 | |
---|
784 | if (size <= 0) |
---|
785 | return RTEMS_INVALID_SIZE; |
---|
786 | |
---|
787 | rtems_bdbuf_ctx.npools = size; |
---|
788 | |
---|
789 | /* |
---|
790 | * Allocate memory for buffer pool descriptors |
---|
791 | */ |
---|
792 | rtems_bdbuf_ctx.pool = calloc(size, sizeof(bdbuf_pool)); |
---|
793 | if (rtems_bdbuf_ctx.pool == NULL) |
---|
794 | { |
---|
795 | return RTEMS_NO_MEMORY; |
---|
796 | } |
---|
797 | |
---|
798 | rtems_chain_initialize_empty(&rtems_bdbuf_ctx.mod); |
---|
799 | |
---|
800 | /* Initialize buffer pools and roll out if something failed */ |
---|
801 | for (i = 0; i < size; i++) |
---|
802 | { |
---|
803 | rc = bdbuf_initialize_pool(conf_table + i, i); |
---|
804 | if (rc != RTEMS_SUCCESSFUL) |
---|
805 | { |
---|
806 | rtems_bdpool_id j; |
---|
807 | for (j = 0; j < i - 1; j++) |
---|
808 | { |
---|
809 | bdbuf_release_pool(j); |
---|
810 | } |
---|
811 | return rc; |
---|
812 | } |
---|
813 | } |
---|
814 | |
---|
815 | /* Create buffer flush semaphore */ |
---|
816 | rc = rtems_semaphore_create( |
---|
817 | rtems_build_name('B', 'F', 'L', 'U'), 0, |
---|
818 | RTEMS_FIFO | RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | |
---|
819 | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, 0, |
---|
820 | &rtems_bdbuf_ctx.flush_sema); |
---|
821 | if (rc != RTEMS_SUCCESSFUL) |
---|
822 | { |
---|
823 | for (i = 0; i < size; i++) |
---|
824 | bdbuf_release_pool(i); |
---|
825 | free(rtems_bdbuf_ctx.pool); |
---|
826 | return rc; |
---|
827 | } |
---|
828 | |
---|
829 | /* Create and start swapout task */ |
---|
830 | rc = rtems_task_create( |
---|
831 | rtems_build_name('B', 'S', 'W', 'P'), |
---|
832 | ((swapout_task_priority > 0) |
---|
833 | ? swapout_task_priority |
---|
834 | : SWAPOUT_TASK_DEFAULT_PRIORITY), |
---|
835 | SWAPOUT_TASK_STACK_SIZE, |
---|
836 | RTEMS_DEFAULT_MODES | RTEMS_NO_PREEMPT, |
---|
837 | RTEMS_DEFAULT_ATTRIBUTES, |
---|
838 | &rtems_bdbuf_ctx.swapout_task); |
---|
839 | if (rc != RTEMS_SUCCESSFUL) |
---|
840 | { |
---|
841 | rtems_semaphore_delete(rtems_bdbuf_ctx.flush_sema); |
---|
842 | for (i = 0; i < size; i++) |
---|
843 | bdbuf_release_pool(i); |
---|
844 | free(rtems_bdbuf_ctx.pool); |
---|
845 | return rc; |
---|
846 | } |
---|
847 | |
---|
848 | rc = rtems_task_start(rtems_bdbuf_ctx.swapout_task, bdbuf_swapout_task, 0); |
---|
849 | if (rc != RTEMS_SUCCESSFUL) |
---|
850 | { |
---|
851 | rtems_task_delete(rtems_bdbuf_ctx.swapout_task); |
---|
852 | rtems_semaphore_delete(rtems_bdbuf_ctx.flush_sema); |
---|
853 | for (i = 0; i < size; i++) |
---|
854 | bdbuf_release_pool(i); |
---|
855 | free(rtems_bdbuf_ctx.pool); |
---|
856 | return rc; |
---|
857 | } |
---|
858 | |
---|
859 | return RTEMS_SUCCESSFUL; |
---|
860 | } |
---|
861 | |
---|
862 | /* find_or_assign_buffer -- |
---|
863 | * Looks for buffer already assigned for this dev/block. If one is found |
---|
864 | * obtain block buffer. If specified block already cached (i.e. there's |
---|
865 | * block in the _modified_, or _recently_used_), return address |
---|
866 | * of appropriate buffer descriptor and increment reference counter to 1. |
---|
867 | * If block is not cached, allocate new buffer and return it. Data |
---|
868 | * shouldn't be read to the buffer from media; buffer contains arbitrary |
---|
869 | * data. This primitive may be blocked if there are no free buffer |
---|
870 | * descriptors available and there are no unused non-modified (or |
---|
871 | * synchronized with media) buffers available. |
---|
872 | * |
---|
873 | * PARAMETERS: |
---|
874 | * device - device number (constructed of major and minor device number |
---|
875 | * block - linear media block number |
---|
876 | * ret_buf - address of the variable to store address of found descriptor |
---|
877 | * |
---|
878 | * RETURNS: |
---|
879 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
880 | * or error code if error is occured) |
---|
881 | * |
---|
882 | * SIDE EFFEECTS: |
---|
883 | * bufget_sema may be obtained by this primitive |
---|
884 | * |
---|
885 | * NOTE: |
---|
886 | * It is assumed that primitive invoked when thread preemption is disabled. |
---|
887 | */ |
---|
888 | static rtems_status_code |
---|
889 | find_or_assign_buffer(disk_device *dd, |
---|
890 | blkdev_bnum block, |
---|
891 | bdbuf_buffer **ret_buf) |
---|
892 | { |
---|
893 | bdbuf_buffer *bd_buf; |
---|
894 | bdbuf_pool *bd_pool; |
---|
895 | rtems_status_code rc; |
---|
896 | dev_t device; |
---|
897 | ISR_Level level; |
---|
898 | |
---|
899 | int blksize; |
---|
900 | |
---|
901 | device = dd->dev; |
---|
902 | bd_pool = rtems_bdbuf_ctx.pool + dd->pool; |
---|
903 | blksize = dd->block_size; |
---|
904 | |
---|
905 | again: |
---|
906 | /* Looking for buffer descriptor used for this dev/block. */ |
---|
907 | bd_buf = avl_search(&bd_pool->tree, device, block); |
---|
908 | |
---|
909 | if (bd_buf == NULL) |
---|
910 | { |
---|
911 | /* Try to obtain semaphore without waiting first. It is the most |
---|
912 | frequent case when reasonable number of buffers configured. If |
---|
913 | it is failed, obtain semaphore blocking on it. In this case |
---|
914 | it should be checked that appropriate buffer hasn't been loaded |
---|
915 | by another thread, because this thread is preempted */ |
---|
916 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, RTEMS_NO_WAIT, 0); |
---|
917 | if (rc == RTEMS_UNSATISFIED) |
---|
918 | { |
---|
919 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, |
---|
920 | RTEMS_WAIT, RTEMS_NO_TIMEOUT); |
---|
921 | bd_buf = avl_search(&bd_pool->tree, device, block); |
---|
922 | if (bd_buf != NULL) |
---|
923 | rtems_semaphore_release(bd_pool->bufget_sema); |
---|
924 | } |
---|
925 | } |
---|
926 | |
---|
927 | if (bd_buf == NULL) |
---|
928 | { |
---|
929 | /* Assign new buffer descriptor */ |
---|
930 | if (rtems_chain_is_empty(&bd_pool->free)) |
---|
931 | { |
---|
932 | bd_buf = (bdbuf_buffer *)rtems_chain_get(&bd_pool->lru); |
---|
933 | if (bd_buf != NULL) |
---|
934 | { |
---|
935 | int avl_result; |
---|
936 | avl_result = avl_remove(&bd_pool->tree, bd_buf); |
---|
937 | if (avl_result != 0) |
---|
938 | { |
---|
939 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
940 | return RTEMS_INTERNAL_ERROR; |
---|
941 | } |
---|
942 | } |
---|
943 | } |
---|
944 | else |
---|
945 | { |
---|
946 | bd_buf = (bdbuf_buffer *)rtems_chain_get(&(bd_pool->free)); |
---|
947 | } |
---|
948 | |
---|
949 | if (bd_buf == NULL) |
---|
950 | { |
---|
951 | goto again; |
---|
952 | } |
---|
953 | else |
---|
954 | { |
---|
955 | bd_buf->dev = device; |
---|
956 | bd_buf->block = block; |
---|
957 | #ifdef AVL_GPL |
---|
958 | bd_buf->avl.link[0] = NULL; |
---|
959 | bd_buf->avl.link[1] = NULL; |
---|
960 | #else |
---|
961 | bd_buf->avl.left = NULL; |
---|
962 | bd_buf->avl.right = NULL; |
---|
963 | #endif |
---|
964 | bd_buf->use_count = 1; |
---|
965 | bd_buf->modified = bd_buf->actual = bd_buf->in_progress = FALSE; |
---|
966 | bd_buf->status = RTEMS_SUCCESSFUL; |
---|
967 | |
---|
968 | if (avl_insert(&bd_pool->tree, bd_buf) != 0) |
---|
969 | { |
---|
970 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
971 | return RTEMS_INTERNAL_ERROR; |
---|
972 | } |
---|
973 | |
---|
974 | *ret_buf = bd_buf; |
---|
975 | |
---|
976 | return RTEMS_SUCCESSFUL; |
---|
977 | } |
---|
978 | } |
---|
979 | else |
---|
980 | { |
---|
981 | /* Buffer descriptor already assigned for this dev/block */ |
---|
982 | if (bd_buf->use_count == 0) |
---|
983 | { |
---|
984 | /* If we are removing from lru list, obtain the bufget_sema |
---|
985 | * first. If we are removing from mod list, obtain flush sema. |
---|
986 | * It should be obtained without blocking because we know |
---|
987 | * that our buffer descriptor is in the list. */ |
---|
988 | if (bd_buf->modified) |
---|
989 | { |
---|
990 | rc = rtems_semaphore_obtain(rtems_bdbuf_ctx.flush_sema, |
---|
991 | RTEMS_NO_WAIT, 0); |
---|
992 | } |
---|
993 | else |
---|
994 | { |
---|
995 | rc = rtems_semaphore_obtain(bd_pool->bufget_sema, |
---|
996 | RTEMS_NO_WAIT, 0); |
---|
997 | } |
---|
998 | /* It is possible that we couldn't obtain flush or bufget sema |
---|
999 | * although buffer in the appropriate chain is available: |
---|
1000 | * semaphore may be released to swapout task, but this task |
---|
1001 | * actually did not start to process it. */ |
---|
1002 | if (rc == RTEMS_UNSATISFIED) |
---|
1003 | rc = RTEMS_SUCCESSFUL; |
---|
1004 | if (rc != RTEMS_SUCCESSFUL) |
---|
1005 | { |
---|
1006 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_CONSISTENCY); |
---|
1007 | return RTEMS_INTERNAL_ERROR; |
---|
1008 | } |
---|
1009 | |
---|
1010 | /* Buffer descriptor is linked to the lru or mod chain. Remove |
---|
1011 | it from there. */ |
---|
1012 | rtems_chain_extract(&bd_buf->link); |
---|
1013 | } |
---|
1014 | bd_buf->use_count++; |
---|
1015 | while (bd_buf->in_progress != 0) |
---|
1016 | { |
---|
1017 | rtems_interrupt_disable(level); |
---|
1018 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
1019 | WATCHDOG_NO_TIMEOUT, level); |
---|
1020 | } |
---|
1021 | |
---|
1022 | *ret_buf = bd_buf; |
---|
1023 | return RTEMS_SUCCESSFUL; |
---|
1024 | } |
---|
1025 | } |
---|
1026 | |
---|
1027 | /* rtems_bdbuf_get -- |
---|
1028 | * Obtain block buffer. If specified block already cached (i.e. there's |
---|
1029 | * block in the _modified_, or _recently_used_), return address |
---|
1030 | * of appropriate buffer descriptor and increment reference counter to 1. |
---|
1031 | * If block is not cached, allocate new buffer and return it. Data |
---|
1032 | * shouldn't be read to the buffer from media; buffer may contains |
---|
1033 | * arbitrary data. This primitive may be blocked if there are no free |
---|
1034 | * buffer descriptors available and there are no unused non-modified |
---|
1035 | * (or synchronized with media) buffers available. |
---|
1036 | * |
---|
1037 | * PARAMETERS: |
---|
1038 | * device - device number (constructed of major and minor device number) |
---|
1039 | * block - linear media block number |
---|
1040 | * bd - address of variable to store pointer to the buffer descriptor |
---|
1041 | * |
---|
1042 | * RETURNS: |
---|
1043 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
1044 | * or error code if error is occured) |
---|
1045 | * |
---|
1046 | * SIDE EFFECTS: |
---|
1047 | * bufget_sema semaphore obtained by this primitive. |
---|
1048 | */ |
---|
1049 | rtems_status_code |
---|
1050 | rtems_bdbuf_get(dev_t device, blkdev_bnum block, bdbuf_buffer **bd) |
---|
1051 | { |
---|
1052 | rtems_status_code rc; |
---|
1053 | disk_device *dd; |
---|
1054 | disk_device *pdd; |
---|
1055 | preemption_key key; |
---|
1056 | |
---|
1057 | /* |
---|
1058 | * Convert logical dev/block to physical one |
---|
1059 | */ |
---|
1060 | dd = rtems_disk_lookup(device); |
---|
1061 | if (dd == NULL) |
---|
1062 | return RTEMS_INVALID_ID; |
---|
1063 | |
---|
1064 | if (block >= dd->size) |
---|
1065 | { |
---|
1066 | rtems_disk_release(dd); |
---|
1067 | return RTEMS_INVALID_NUMBER; |
---|
1068 | } |
---|
1069 | |
---|
1070 | pdd = dd->phys_dev; |
---|
1071 | block += dd->start; |
---|
1072 | rtems_disk_release(dd); |
---|
1073 | |
---|
1074 | DISABLE_PREEMPTION(key); |
---|
1075 | rc = find_or_assign_buffer(pdd, block, bd); |
---|
1076 | ENABLE_PREEMPTION(key); |
---|
1077 | |
---|
1078 | if (rc != RTEMS_SUCCESSFUL) |
---|
1079 | return rc; |
---|
1080 | |
---|
1081 | return RTEMS_SUCCESSFUL; |
---|
1082 | } |
---|
1083 | |
---|
1084 | /* bdbuf_initialize_transfer_sema -- |
---|
1085 | * Initialize transfer_sema mutex semaphore associated with buffer |
---|
1086 | * descriptor. |
---|
1087 | */ |
---|
1088 | static inline void |
---|
1089 | bdbuf_initialize_transfer_sema(bdbuf_buffer *bd_buf) |
---|
1090 | { |
---|
1091 | CORE_mutex_Attributes mutex_attr; |
---|
1092 | mutex_attr.lock_nesting_behavior = CORE_MUTEX_NESTING_BLOCKS; |
---|
1093 | mutex_attr.only_owner_release = FALSE; |
---|
1094 | mutex_attr.discipline = CORE_MUTEX_DISCIPLINES_FIFO; |
---|
1095 | mutex_attr.priority_ceiling = 0; |
---|
1096 | |
---|
1097 | _CORE_mutex_Initialize(&bd_buf->transfer_sema, |
---|
1098 | &mutex_attr, CORE_MUTEX_LOCKED); |
---|
1099 | } |
---|
1100 | |
---|
1101 | /* bdbuf_write_transfer_done -- |
---|
1102 | * Callout function. Invoked by block device driver when data transfer |
---|
1103 | * to device (write) is completed. This function may be invoked from |
---|
1104 | * interrupt handler. |
---|
1105 | * |
---|
1106 | * PARAMETERS: |
---|
1107 | * arg - arbitrary argument specified in block device request |
---|
1108 | * structure (in this case - pointer to the appropriate |
---|
1109 | * bdbuf_buffer buffer descriptor structure). |
---|
1110 | * status - I/O completion status |
---|
1111 | * error - errno error code if status != RTEMS_SUCCESSFUL |
---|
1112 | * |
---|
1113 | * RETURNS: |
---|
1114 | * none |
---|
1115 | */ |
---|
1116 | static void |
---|
1117 | bdbuf_write_transfer_done(void *arg, rtems_status_code status, int error) |
---|
1118 | { |
---|
1119 | int i; |
---|
1120 | write_tfer_done_arg_t *wtd_arg = arg; |
---|
1121 | blkdev_request *req = wtd_arg->req; |
---|
1122 | bdbuf_buffer **bd_buf_write_store = wtd_arg->write_store; |
---|
1123 | bdbuf_buffer *bd_buf; |
---|
1124 | for (i = 0;i < req->count;i++) { |
---|
1125 | bd_buf = bd_buf_write_store[i]; |
---|
1126 | bd_buf->status = status; |
---|
1127 | bd_buf->error = RTEMS_IO_ERROR; |
---|
1128 | |
---|
1129 | bd_buf->in_progress = FALSE; |
---|
1130 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
1131 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
1132 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
1133 | } |
---|
1134 | } |
---|
1135 | |
---|
1136 | /* bdbuf_read_transfer_done -- |
---|
1137 | * Callout function. Invoked by block device driver when data transfer |
---|
1138 | * from device (read) is completed. This function may be invoked from |
---|
1139 | * interrupt handler. |
---|
1140 | * |
---|
1141 | * PARAMETERS: |
---|
1142 | * arg - arbitrary argument specified in block device request |
---|
1143 | * structure (in this case - pointer to the appropriate |
---|
1144 | * bdbuf_buffer buffer descriptor structure). |
---|
1145 | * status - I/O completion status |
---|
1146 | * error - errno error code if status != RTEMS_SUCCESSFUL |
---|
1147 | * |
---|
1148 | * RETURNS: |
---|
1149 | * none |
---|
1150 | */ |
---|
1151 | static void |
---|
1152 | bdbuf_read_transfer_done(void *arg, rtems_status_code status, int error) |
---|
1153 | { |
---|
1154 | #if defined(READ_MULTIPLE) |
---|
1155 | |
---|
1156 | read_ahead_bd_buf_group *bd_buf_group = arg; |
---|
1157 | bdbuf_buffer *bd_buf; |
---|
1158 | int i; |
---|
1159 | for (i = 0;i < bd_buf_group->cnt;i++) { |
---|
1160 | bd_buf = bd_buf_group->bd_bufs[i]; |
---|
1161 | |
---|
1162 | bd_buf->status = status; |
---|
1163 | bd_buf->error = RTEMS_IO_ERROR; |
---|
1164 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
1165 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
1166 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
1167 | } |
---|
1168 | #else |
---|
1169 | bdbuf_buffer *bd_buf = arg; |
---|
1170 | bd_buf->status = status; |
---|
1171 | bd_buf->error = RTEMS_IO_ERROR; |
---|
1172 | _CORE_mutex_Surrender(&bd_buf->transfer_sema, 0, NULL); |
---|
1173 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
1174 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
1175 | #endif |
---|
1176 | } |
---|
1177 | |
---|
1178 | /* rtems_bdbuf_read -- |
---|
1179 | * (Similar to the rtems_bdbuf_get, except reading data from media) |
---|
1180 | * Obtain block buffer. If specified block already cached, return address |
---|
1181 | * of appropriate buffer and increment reference counter to 1. If block is |
---|
1182 | * not cached, allocate new buffer and read data to it from the media. |
---|
1183 | * This primitive may be blocked on waiting until data to be read from |
---|
1184 | * media, if there are no free buffer descriptors available and there are |
---|
1185 | * no unused non-modified (or synchronized with media) buffers available. |
---|
1186 | * |
---|
1187 | * PARAMETERS: |
---|
1188 | * device - device number (consists of major and minor device number) |
---|
1189 | * block - linear media block number |
---|
1190 | * bd - address of variable to store pointer to the buffer descriptor |
---|
1191 | * |
---|
1192 | * RETURNS: |
---|
1193 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
1194 | * or error code if error is occured) |
---|
1195 | * |
---|
1196 | * SIDE EFFECTS: |
---|
1197 | * bufget_sema and transfer_sema semaphores obtained by this primitive. |
---|
1198 | */ |
---|
1199 | #if !defined(READ_MULTIPLE) |
---|
1200 | rtems_status_code |
---|
1201 | rtems_bdbuf_read(dev_t device, |
---|
1202 | blkdev_bnum block, |
---|
1203 | bdbuf_buffer **bd) |
---|
1204 | { |
---|
1205 | preemption_key key; |
---|
1206 | ISR_Level level; |
---|
1207 | |
---|
1208 | bdbuf_buffer *bd_buf; |
---|
1209 | rtems_status_code rc; |
---|
1210 | int result; |
---|
1211 | disk_device *dd; |
---|
1212 | disk_device *pdd; |
---|
1213 | blkdev_request1 req; |
---|
1214 | |
---|
1215 | dd = rtems_disk_lookup(device); |
---|
1216 | if (dd == NULL) |
---|
1217 | return RTEMS_INVALID_ID; |
---|
1218 | |
---|
1219 | if (block >= dd->size) |
---|
1220 | { |
---|
1221 | rtems_disk_release(dd); |
---|
1222 | return RTEMS_INVALID_NUMBER; |
---|
1223 | } |
---|
1224 | |
---|
1225 | pdd = dd->phys_dev; |
---|
1226 | block += dd->start; |
---|
1227 | |
---|
1228 | DISABLE_PREEMPTION(key); |
---|
1229 | rc = find_or_assign_buffer(pdd, block, &bd_buf); |
---|
1230 | |
---|
1231 | if (rc != RTEMS_SUCCESSFUL) |
---|
1232 | { |
---|
1233 | ENABLE_PREEMPTION(key); |
---|
1234 | rtems_disk_release(dd); |
---|
1235 | return rc; |
---|
1236 | } |
---|
1237 | |
---|
1238 | if (!bd_buf->actual) |
---|
1239 | { |
---|
1240 | bd_buf->in_progress = 1; |
---|
1241 | |
---|
1242 | req.req.req = BLKDEV_REQ_READ; |
---|
1243 | req.req.req_done = bdbuf_read_transfer_done; |
---|
1244 | req.req.done_arg = bd_buf; |
---|
1245 | req.req.start = block; |
---|
1246 | req.req.count = 1; |
---|
1247 | req.req.bufnum = 1; |
---|
1248 | req.req.bufs[0].length = dd->block_size; |
---|
1249 | req.req.bufs[0].buffer = bd_buf->buffer; |
---|
1250 | |
---|
1251 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
1252 | result = dd->ioctl(pdd->dev, BLKIO_REQUEST, &req); |
---|
1253 | if (result == -1) |
---|
1254 | { |
---|
1255 | bd_buf->status = RTEMS_IO_ERROR; |
---|
1256 | bd_buf->error = errno; |
---|
1257 | bd_buf->actual = FALSE; |
---|
1258 | } |
---|
1259 | else |
---|
1260 | { |
---|
1261 | rtems_interrupt_disable(level); |
---|
1262 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
1263 | WATCHDOG_NO_TIMEOUT, level); |
---|
1264 | bd_buf->actual = TRUE; |
---|
1265 | } |
---|
1266 | bd_buf->in_progress = FALSE; |
---|
1267 | } |
---|
1268 | rtems_disk_release(dd); |
---|
1269 | |
---|
1270 | ENABLE_PREEMPTION(key); |
---|
1271 | |
---|
1272 | *bd = bd_buf; |
---|
1273 | |
---|
1274 | return RTEMS_SUCCESSFUL; |
---|
1275 | } |
---|
1276 | #else /* READ_MULTIPLE */ |
---|
1277 | rtems_status_code |
---|
1278 | rtems_bdbuf_read(dev_t device, |
---|
1279 | blkdev_bnum block, |
---|
1280 | bdbuf_buffer **bd) |
---|
1281 | { |
---|
1282 | preemption_key key; |
---|
1283 | ISR_Level level; |
---|
1284 | |
---|
1285 | bdbuf_buffer *bd_buf,*first_bd_buf; |
---|
1286 | rtems_status_code rc; |
---|
1287 | int result; |
---|
1288 | disk_device *dd; |
---|
1289 | disk_device *pdd; |
---|
1290 | blkdev_request_read_ahead req; |
---|
1291 | read_ahead_bd_buf_group bd_buf_group; |
---|
1292 | boolean find_more_buffers; |
---|
1293 | int i; |
---|
1294 | |
---|
1295 | dd = rtems_disk_lookup(device); |
---|
1296 | if (dd == NULL) |
---|
1297 | return RTEMS_INVALID_ID; |
---|
1298 | |
---|
1299 | if (block >= dd->size) |
---|
1300 | { |
---|
1301 | rtems_disk_release(dd); |
---|
1302 | return RTEMS_INVALID_NUMBER; |
---|
1303 | } |
---|
1304 | |
---|
1305 | pdd = dd->phys_dev; |
---|
1306 | block += dd->start; |
---|
1307 | |
---|
1308 | DISABLE_PREEMPTION(key); |
---|
1309 | rc = find_or_assign_buffer(pdd, block, &first_bd_buf); |
---|
1310 | |
---|
1311 | if (rc != RTEMS_SUCCESSFUL) |
---|
1312 | { |
---|
1313 | ENABLE_PREEMPTION(key); |
---|
1314 | rtems_disk_release(dd); |
---|
1315 | return rc; |
---|
1316 | } |
---|
1317 | if (!first_bd_buf->actual) |
---|
1318 | { |
---|
1319 | |
---|
1320 | bd_buf_group.bd_bufs[0] = first_bd_buf; |
---|
1321 | bd_buf_group.cnt = 1; |
---|
1322 | |
---|
1323 | first_bd_buf->in_progress = TRUE; |
---|
1324 | |
---|
1325 | req.req.req = BLKDEV_REQ_READ; |
---|
1326 | req.req.req_done = bdbuf_read_transfer_done; |
---|
1327 | req.req.done_arg = &bd_buf_group; |
---|
1328 | req.req.start = block; |
---|
1329 | req.req.count = 1; |
---|
1330 | req.req.bufnum = 1; |
---|
1331 | req.req.bufs[0].length = dd->block_size; |
---|
1332 | req.req.bufs[0].buffer = first_bd_buf->buffer; |
---|
1333 | |
---|
1334 | bdbuf_initialize_transfer_sema(first_bd_buf); |
---|
1335 | /* |
---|
1336 | * FIXME: check for following blocks to be: |
---|
1337 | * - still in range of partition size |
---|
1338 | * - not yet assigned |
---|
1339 | * - buffer available |
---|
1340 | * allocate for read call, if possible |
---|
1341 | */ |
---|
1342 | find_more_buffers = TRUE; |
---|
1343 | while (find_more_buffers) { |
---|
1344 | block++; |
---|
1345 | /* |
---|
1346 | * still bd_buf_group entries free and |
---|
1347 | * still in range of this disk? |
---|
1348 | */ |
---|
1349 | if ((bd_buf_group.cnt >= READ_AHEAD_MAX_BLK_CNT) || |
---|
1350 | (block >= dd->size)) { |
---|
1351 | find_more_buffers = FALSE; |
---|
1352 | } |
---|
1353 | if (find_more_buffers) { |
---|
1354 | rc = find_or_assign_buffer(pdd, block, &bd_buf); |
---|
1355 | if (rc != RTEMS_SUCCESSFUL) { |
---|
1356 | find_more_buffers = FALSE; |
---|
1357 | } |
---|
1358 | else if (bd_buf->actual) { |
---|
1359 | find_more_buffers = FALSE; |
---|
1360 | bdbuf_release(bd_buf); |
---|
1361 | } |
---|
1362 | } |
---|
1363 | if (find_more_buffers) { |
---|
1364 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
1365 | bd_buf->in_progress = TRUE; |
---|
1366 | |
---|
1367 | req.req.bufs[req.req.count].length = dd->block_size; |
---|
1368 | req.req.bufs[req.req.count].buffer = bd_buf->buffer; |
---|
1369 | req.req.count++; |
---|
1370 | req.req.bufnum++; |
---|
1371 | bd_buf_group.bd_bufs[bd_buf_group.cnt] = bd_buf; |
---|
1372 | bd_buf_group.cnt++; |
---|
1373 | } |
---|
1374 | } |
---|
1375 | |
---|
1376 | /* do the actual read call here |
---|
1377 | */ |
---|
1378 | result = dd->ioctl(pdd->dev, BLKIO_REQUEST, &req); |
---|
1379 | |
---|
1380 | /* |
---|
1381 | * cleanup: |
---|
1382 | * wait, until all bd_bufs are processed |
---|
1383 | * set status in all bd_bufs |
---|
1384 | */ |
---|
1385 | for (i = 0;i < bd_buf_group.cnt;i++) { |
---|
1386 | bd_buf = bd_buf_group.bd_bufs[i]; |
---|
1387 | if (result == -1) |
---|
1388 | { |
---|
1389 | bd_buf->status = RTEMS_IO_ERROR; |
---|
1390 | bd_buf->error = errno; |
---|
1391 | bd_buf->actual = FALSE; |
---|
1392 | } |
---|
1393 | else |
---|
1394 | { |
---|
1395 | rtems_interrupt_disable(level); |
---|
1396 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
1397 | WATCHDOG_NO_TIMEOUT, level); |
---|
1398 | bd_buf->actual = TRUE; |
---|
1399 | } |
---|
1400 | bd_buf->in_progress = FALSE; |
---|
1401 | /* release any pre-read buffers */ |
---|
1402 | if (i > 0) { |
---|
1403 | bdbuf_release(bd_buf); |
---|
1404 | } |
---|
1405 | } |
---|
1406 | } |
---|
1407 | rtems_disk_release(dd); |
---|
1408 | |
---|
1409 | ENABLE_PREEMPTION(key); |
---|
1410 | |
---|
1411 | *bd = first_bd_buf; |
---|
1412 | |
---|
1413 | return RTEMS_SUCCESSFUL; |
---|
1414 | } |
---|
1415 | #endif /* READ_MULTIPLE */ |
---|
1416 | |
---|
1417 | |
---|
1418 | /* bdbuf_release -- |
---|
1419 | * Release buffer. Decrease buffer usage counter. If it is zero, further |
---|
1420 | * processing depends on modified attribute. If buffer was modified, it |
---|
1421 | * is inserted into mod chain and swapout task waken up. If buffer was |
---|
1422 | * not modified, it is returned to the end of lru chain making it available |
---|
1423 | * for further use. |
---|
1424 | * |
---|
1425 | * PARAMETERS: |
---|
1426 | * bd_buf - pointer to the released buffer descriptor. |
---|
1427 | * |
---|
1428 | * RETURNS: |
---|
1429 | * RTEMS_SUCCESSFUL if buffer released successfully, or error code if |
---|
1430 | * error occured. |
---|
1431 | * |
---|
1432 | * NOTE: |
---|
1433 | * This is internal function. It is assumed that task made non-preemptive |
---|
1434 | * before its invocation. |
---|
1435 | */ |
---|
1436 | static rtems_status_code |
---|
1437 | bdbuf_release(bdbuf_buffer *bd_buf) |
---|
1438 | { |
---|
1439 | bdbuf_pool *bd_pool; |
---|
1440 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
1441 | |
---|
1442 | if (bd_buf->use_count <= 0) |
---|
1443 | return RTEMS_INTERNAL_ERROR; |
---|
1444 | |
---|
1445 | bd_pool = rtems_bdbuf_ctx.pool + bd_buf->pool; |
---|
1446 | |
---|
1447 | bd_buf->use_count--; |
---|
1448 | |
---|
1449 | if (bd_buf->use_count == 0) |
---|
1450 | { |
---|
1451 | if (bd_buf->modified) |
---|
1452 | { |
---|
1453 | |
---|
1454 | /* Buffer was modified. Insert buffer to the modified buffers |
---|
1455 | * list and initiate flushing. */ |
---|
1456 | rtems_chain_append(&rtems_bdbuf_ctx.mod, &bd_buf->link); |
---|
1457 | |
---|
1458 | /* Release the flush_sema */ |
---|
1459 | rc = rtems_semaphore_release(rtems_bdbuf_ctx.flush_sema); |
---|
1460 | } |
---|
1461 | else |
---|
1462 | { |
---|
1463 | /* Buffer was not modified. Add this descriptor to the |
---|
1464 | * end of lru chain and make it available for reuse. */ |
---|
1465 | rtems_chain_append(&bd_pool->lru, &bd_buf->link); |
---|
1466 | rc = rtems_semaphore_release(bd_pool->bufget_sema); |
---|
1467 | } |
---|
1468 | } |
---|
1469 | return rc; |
---|
1470 | } |
---|
1471 | |
---|
1472 | |
---|
1473 | /* rtems_bdbuf_release -- |
---|
1474 | * Release buffer allocated before. This primitive decrease the |
---|
1475 | * usage counter. If it is zero, further destiny of buffer depends on |
---|
1476 | * 'modified' status. If buffer was modified, it is placed to the end of |
---|
1477 | * mod list and flush task waken up. If buffer was not modified, |
---|
1478 | * it is placed to the end of lru list, and bufget_sema released, allowing |
---|
1479 | * to reuse this buffer. |
---|
1480 | * |
---|
1481 | * PARAMETERS: |
---|
1482 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
1483 | * get/read primitive. |
---|
1484 | * |
---|
1485 | * RETURNS: |
---|
1486 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
1487 | * or error code if error is occured) |
---|
1488 | * |
---|
1489 | * SIDE EFFECTS: |
---|
1490 | * flush_sema and bufget_sema semaphores may be released by this primitive. |
---|
1491 | */ |
---|
1492 | rtems_status_code |
---|
1493 | rtems_bdbuf_release(bdbuf_buffer *bd_buf) |
---|
1494 | { |
---|
1495 | preemption_key key; |
---|
1496 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
1497 | |
---|
1498 | if (bd_buf == NULL) |
---|
1499 | return RTEMS_INVALID_ADDRESS; |
---|
1500 | |
---|
1501 | DISABLE_PREEMPTION(key); |
---|
1502 | |
---|
1503 | rc = bdbuf_release(bd_buf); |
---|
1504 | |
---|
1505 | ENABLE_PREEMPTION(key); |
---|
1506 | |
---|
1507 | return rc; |
---|
1508 | } |
---|
1509 | |
---|
1510 | /* rtems_bdbuf_release_modified -- |
---|
1511 | * Release buffer allocated before, assuming that it is _modified_ by |
---|
1512 | * it's owner. This primitive decrease usage counter for buffer, mark |
---|
1513 | * buffer descriptor as modified. If usage counter is 0, insert it at |
---|
1514 | * end of mod chain and release flush_sema semaphore to activate the |
---|
1515 | * flush task. |
---|
1516 | * |
---|
1517 | * PARAMETERS: |
---|
1518 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
1519 | * get/read primitive. |
---|
1520 | * |
---|
1521 | * RETURNS: |
---|
1522 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
1523 | * or error code if error is occured) |
---|
1524 | * |
---|
1525 | * SIDE EFFECTS: |
---|
1526 | * flush_sema semaphore may be released by this primitive. |
---|
1527 | */ |
---|
1528 | rtems_status_code |
---|
1529 | rtems_bdbuf_release_modified(bdbuf_buffer *bd_buf) |
---|
1530 | { |
---|
1531 | preemption_key key; |
---|
1532 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
1533 | |
---|
1534 | if (bd_buf == NULL) |
---|
1535 | return RTEMS_INVALID_ADDRESS; |
---|
1536 | |
---|
1537 | DISABLE_PREEMPTION(key); |
---|
1538 | |
---|
1539 | if (!bd_buf->modified) |
---|
1540 | { |
---|
1541 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
1542 | } |
---|
1543 | bd_buf->modified = TRUE; |
---|
1544 | bd_buf->actual = TRUE; |
---|
1545 | rc = bdbuf_release(bd_buf); |
---|
1546 | |
---|
1547 | ENABLE_PREEMPTION(key); |
---|
1548 | |
---|
1549 | return rc; |
---|
1550 | } |
---|
1551 | |
---|
1552 | /* rtems_bdbuf_sync -- |
---|
1553 | * Wait until specified buffer synchronized with disk. Invoked on exchanges |
---|
1554 | * critical for data consistency on the media. This primitive mark owned |
---|
1555 | * block as modified, decrease usage counter. If usage counter is 0, |
---|
1556 | * block inserted to the mod chain and flush_sema semaphore released. |
---|
1557 | * Finally, primitives blocked on transfer_sema semaphore. |
---|
1558 | * |
---|
1559 | * PARAMETERS: |
---|
1560 | * bd_buf - pointer to the bdbuf_buffer structure previously obtained using |
---|
1561 | * get/read primitive. |
---|
1562 | * |
---|
1563 | * RETURNS: |
---|
1564 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
1565 | * or error code if error is occured) |
---|
1566 | * |
---|
1567 | * SIDE EFFECTS: |
---|
1568 | * Primitive may be blocked on transfer_sema semaphore. |
---|
1569 | */ |
---|
1570 | rtems_status_code |
---|
1571 | rtems_bdbuf_sync(bdbuf_buffer *bd_buf) |
---|
1572 | { |
---|
1573 | preemption_key key; |
---|
1574 | ISR_Level level; |
---|
1575 | rtems_status_code rc = RTEMS_SUCCESSFUL; |
---|
1576 | |
---|
1577 | if (bd_buf == NULL) |
---|
1578 | return RTEMS_INVALID_ADDRESS; |
---|
1579 | |
---|
1580 | DISABLE_PREEMPTION(key); |
---|
1581 | |
---|
1582 | if (!bd_buf->modified) |
---|
1583 | { |
---|
1584 | bdbuf_initialize_transfer_sema(bd_buf); |
---|
1585 | } |
---|
1586 | bd_buf->modified = TRUE; |
---|
1587 | bd_buf->actual = TRUE; |
---|
1588 | |
---|
1589 | rc = bdbuf_release(bd_buf); |
---|
1590 | |
---|
1591 | if (rc == RTEMS_SUCCESSFUL) |
---|
1592 | { |
---|
1593 | rtems_interrupt_disable(level); |
---|
1594 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
1595 | WATCHDOG_NO_TIMEOUT, level); |
---|
1596 | } |
---|
1597 | |
---|
1598 | ENABLE_PREEMPTION(key); |
---|
1599 | |
---|
1600 | return rc; |
---|
1601 | } |
---|
1602 | |
---|
1603 | /* rtems_bdbuf_syncdev -- |
---|
1604 | * Synchronize with disk all buffers containing the blocks belonging to |
---|
1605 | * specified device. |
---|
1606 | * |
---|
1607 | * PARAMETERS: |
---|
1608 | * dev - block device number |
---|
1609 | * |
---|
1610 | * RETURNS: |
---|
1611 | * RTEMS status code (RTEMS_SUCCESSFUL if operation completed successfully |
---|
1612 | * or error code if error is occured) |
---|
1613 | */ |
---|
1614 | rtems_status_code |
---|
1615 | rtems_bdbuf_syncdev(dev_t dev) |
---|
1616 | { |
---|
1617 | preemption_key key; |
---|
1618 | ISR_Level level; |
---|
1619 | |
---|
1620 | bdbuf_buffer *bd_buf; |
---|
1621 | disk_device *dd; |
---|
1622 | bdbuf_pool *pool; |
---|
1623 | |
---|
1624 | dd = rtems_disk_lookup(dev); |
---|
1625 | if (dd == NULL) |
---|
1626 | return RTEMS_INVALID_ID; |
---|
1627 | |
---|
1628 | pool = rtems_bdbuf_ctx.pool + dd->pool; |
---|
1629 | |
---|
1630 | DISABLE_PREEMPTION(key); |
---|
1631 | do { |
---|
1632 | bd_buf = avl_search_for_sync(&pool->tree, dd); |
---|
1633 | if (bd_buf != NULL /* && bd_buf->modified */) |
---|
1634 | { |
---|
1635 | rtems_interrupt_disable(level); |
---|
1636 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, |
---|
1637 | WATCHDOG_NO_TIMEOUT, level); |
---|
1638 | } |
---|
1639 | } while (bd_buf != NULL); |
---|
1640 | ENABLE_PREEMPTION(key); |
---|
1641 | return rtems_disk_release(dd); |
---|
1642 | } |
---|
1643 | |
---|
1644 | /* bdbuf_swapout_task -- |
---|
1645 | * Body of task which take care on flushing modified buffers to the |
---|
1646 | * disk. |
---|
1647 | */ |
---|
1648 | static rtems_task |
---|
1649 | bdbuf_swapout_task(rtems_task_argument unused) |
---|
1650 | { |
---|
1651 | rtems_status_code rc; |
---|
1652 | int result; |
---|
1653 | int i; |
---|
1654 | ISR_Level level; |
---|
1655 | bdbuf_buffer *bd_buf; |
---|
1656 | bdbuf_buffer *nxt_bd_buf; |
---|
1657 | bdbuf_pool *bd_pool = NULL; |
---|
1658 | disk_device *dd = NULL; |
---|
1659 | struct { |
---|
1660 | blkdev_request req; |
---|
1661 | blkdev_sg_buffer sg[SWAP_OUT_MAX_BLK_CNT]; |
---|
1662 | } req; |
---|
1663 | write_tfer_done_arg_t write_tfer_done_arg; |
---|
1664 | |
---|
1665 | /* |
---|
1666 | * provide info needed for write_transfer_done function |
---|
1667 | */ |
---|
1668 | write_tfer_done_arg.req = (blkdev_request *)&req.req; |
---|
1669 | write_tfer_done_arg.write_store = bd_buf_write_store; |
---|
1670 | nxt_bd_buf = NULL; |
---|
1671 | while (1) |
---|
1672 | { |
---|
1673 | req.req.req = BLKDEV_REQ_WRITE; |
---|
1674 | req.req.req_done = bdbuf_write_transfer_done; |
---|
1675 | req.req.done_arg = &write_tfer_done_arg; |
---|
1676 | req.req.count = 0; |
---|
1677 | req.req.bufnum = 0; |
---|
1678 | bd_buf = NULL; |
---|
1679 | do { |
---|
1680 | /* |
---|
1681 | * if a buffer was left over from last loop, then use this buffer |
---|
1682 | * otherwise fetch new buffer from chain. |
---|
1683 | * Wait for buffer, if this is the first one of the request, |
---|
1684 | * otherwise do not wait, if no buffer available |
---|
1685 | */ |
---|
1686 | if (nxt_bd_buf == NULL) { |
---|
1687 | rc = rtems_semaphore_obtain(rtems_bdbuf_ctx.flush_sema, |
---|
1688 | (req.req.count == 0) |
---|
1689 | ? RTEMS_WAIT |
---|
1690 | : RTEMS_NO_WAIT, |
---|
1691 | 0); |
---|
1692 | if (rc == RTEMS_SUCCESSFUL) { |
---|
1693 | nxt_bd_buf = (bdbuf_buffer *)rtems_chain_get(&rtems_bdbuf_ctx.mod); |
---|
1694 | if (nxt_bd_buf != NULL) { |
---|
1695 | nxt_bd_buf->in_progress = TRUE; |
---|
1696 | /* IMD try: clear "modified" bit early */ |
---|
1697 | /* (and not in bdbuf_write_transfer_done) to allow */ |
---|
1698 | /* another modification during write processing */ |
---|
1699 | nxt_bd_buf->modified = FALSE; |
---|
1700 | |
---|
1701 | nxt_bd_buf->use_count++; |
---|
1702 | } |
---|
1703 | } |
---|
1704 | else if ((rc != RTEMS_UNSATISFIED) && |
---|
1705 | (rc != RTEMS_TIMEOUT)) { |
---|
1706 | rtems_fatal_error_occurred(BLKDEV_FATAL_BDBUF_SWAPOUT); |
---|
1707 | } |
---|
1708 | } |
---|
1709 | /* |
---|
1710 | * It is possible that flush_sema semaphore will be released, but |
---|
1711 | * buffer to be removed from mod chain before swapout task start |
---|
1712 | * its processing. |
---|
1713 | */ |
---|
1714 | if ((req.req.count == 0) || /* first bd_buf for this request */ |
---|
1715 | ((nxt_bd_buf != NULL) && |
---|
1716 | (nxt_bd_buf->dev == bd_buf->dev) && /* same device */ |
---|
1717 | (nxt_bd_buf->block == bd_buf->block+1))) {/* next block */ |
---|
1718 | bd_buf = nxt_bd_buf; |
---|
1719 | nxt_bd_buf = NULL; |
---|
1720 | } |
---|
1721 | else { |
---|
1722 | bd_buf = NULL; |
---|
1723 | } |
---|
1724 | /* |
---|
1725 | * here we have three possible states: |
---|
1726 | * bd_buf == NULL, nxt_bd_buf == NULL: no further block available |
---|
1727 | * bd_buf != NULL, nxt_bd_buf == NULL: append bd_buf to request |
---|
1728 | * bd_buf == NULL, nxt_bd_buf != NULL: nxt_bd_buf canot be appended |
---|
1729 | * to current request, keep it |
---|
1730 | * for next main loop |
---|
1731 | */ |
---|
1732 | if (bd_buf != NULL) { |
---|
1733 | bd_pool = rtems_bdbuf_ctx.pool + bd_buf->pool; |
---|
1734 | if (req.req.count == 0) { |
---|
1735 | /* |
---|
1736 | * this is the first block, so use its address |
---|
1737 | */ |
---|
1738 | dd = rtems_disk_lookup(bd_buf->dev); |
---|
1739 | req.req.start = bd_buf->block + dd->start; |
---|
1740 | } |
---|
1741 | req.req.bufs[req.req.bufnum].length = dd->block_size; |
---|
1742 | req.req.bufs[req.req.bufnum].buffer = bd_buf->buffer; |
---|
1743 | /* |
---|
1744 | * keep bd_buf for postprocessing |
---|
1745 | */ |
---|
1746 | bd_buf_write_store[req.req.bufnum] = bd_buf; |
---|
1747 | req.req.count++; |
---|
1748 | req.req.bufnum++; |
---|
1749 | } |
---|
1750 | } while ((bd_buf != NULL) && |
---|
1751 | (req.req.count < SWAP_OUT_MAX_BLK_CNT)); |
---|
1752 | |
---|
1753 | /* transfer_sema initialized when bd_buf inserted in the mod chain |
---|
1754 | first time */ |
---|
1755 | result = dd->ioctl(dd->phys_dev->dev, BLKIO_REQUEST, &req); |
---|
1756 | |
---|
1757 | rtems_disk_release(dd); |
---|
1758 | |
---|
1759 | for (i = 0;i < req.req.count;i++) { |
---|
1760 | bd_buf = bd_buf_write_store[i]; |
---|
1761 | if (result == -1) |
---|
1762 | { |
---|
1763 | |
---|
1764 | bd_buf->status = RTEMS_IO_ERROR; |
---|
1765 | bd_buf->error = errno; |
---|
1766 | /* Release tasks waiting on syncing this buffer */ |
---|
1767 | _CORE_mutex_Flush(&bd_buf->transfer_sema, NULL, |
---|
1768 | CORE_MUTEX_STATUS_SUCCESSFUL); |
---|
1769 | } |
---|
1770 | else |
---|
1771 | { |
---|
1772 | if (bd_buf->in_progress) |
---|
1773 | { |
---|
1774 | rtems_interrupt_disable(level); |
---|
1775 | _CORE_mutex_Seize(&bd_buf->transfer_sema, 0, TRUE, 0, level); |
---|
1776 | } |
---|
1777 | } |
---|
1778 | bd_buf->use_count--; |
---|
1779 | |
---|
1780 | /* Another task have chance to use this buffer, or even |
---|
1781 | * modify it. If buffer is not in use, insert it in appropriate chain |
---|
1782 | * and release semaphore */ |
---|
1783 | if (bd_buf->use_count == 0) |
---|
1784 | { |
---|
1785 | if (bd_buf->modified) |
---|
1786 | { |
---|
1787 | rtems_chain_append(&rtems_bdbuf_ctx.mod, &bd_buf->link); |
---|
1788 | rc = rtems_semaphore_release(rtems_bdbuf_ctx.flush_sema); |
---|
1789 | } |
---|
1790 | else |
---|
1791 | { |
---|
1792 | rtems_chain_append(&bd_pool->lru, &bd_buf->link); |
---|
1793 | rc = rtems_semaphore_release(bd_pool->bufget_sema); |
---|
1794 | } |
---|
1795 | } |
---|
1796 | } |
---|
1797 | } |
---|
1798 | } |
---|
1799 | |
---|
1800 | /* rtems_bdbuf_find_pool -- |
---|
1801 | * Find first appropriate buffer pool. This primitive returns the index |
---|
1802 | * of first buffer pool which block size is greater than or equal to |
---|
1803 | * specified size. |
---|
1804 | * |
---|
1805 | * PARAMETERS: |
---|
1806 | * block_size - requested block size |
---|
1807 | * pool - placeholder for result |
---|
1808 | * |
---|
1809 | * RETURNS: |
---|
1810 | * RTEMS status code: RTEMS_SUCCESSFUL if operation completed successfully, |
---|
1811 | * RTEMS_INVALID_SIZE if specified block size is invalid (not a power |
---|
1812 | * of 2), RTEMS_NOT_DEFINED if buffer pool for this or greater block size |
---|
1813 | * is not configured. |
---|
1814 | */ |
---|
1815 | rtems_status_code |
---|
1816 | rtems_bdbuf_find_pool(int block_size, rtems_bdpool_id *pool) |
---|
1817 | { |
---|
1818 | rtems_bdpool_id i; |
---|
1819 | bdbuf_pool *p; |
---|
1820 | int cursize = INT_MAX; |
---|
1821 | rtems_bdpool_id curid = -1; |
---|
1822 | rtems_boolean found = FALSE; |
---|
1823 | int j; |
---|
1824 | |
---|
1825 | for (j = block_size; (j != 0) && ((j & 1) == 0); j >>= 1); |
---|
1826 | if (j != 1) |
---|
1827 | return RTEMS_INVALID_SIZE; |
---|
1828 | |
---|
1829 | for (i = 0, p = rtems_bdbuf_ctx.pool; i < rtems_bdbuf_ctx.npools; i++, p++) |
---|
1830 | { |
---|
1831 | if ((p->blksize >= block_size) && |
---|
1832 | (p->blksize < cursize)) |
---|
1833 | { |
---|
1834 | curid = i; |
---|
1835 | cursize = p->blksize; |
---|
1836 | found = TRUE; |
---|
1837 | } |
---|
1838 | } |
---|
1839 | |
---|
1840 | if (found) |
---|
1841 | { |
---|
1842 | if (pool != NULL) |
---|
1843 | *pool = curid; |
---|
1844 | return RTEMS_SUCCESSFUL; |
---|
1845 | } |
---|
1846 | else |
---|
1847 | { |
---|
1848 | return RTEMS_NOT_DEFINED; |
---|
1849 | } |
---|
1850 | } |
---|
1851 | |
---|
1852 | /* rtems_bdbuf_get_pool_info -- |
---|
1853 | * Obtain characteristics of buffer pool with specified number. |
---|
1854 | * |
---|
1855 | * PARAMETERS: |
---|
1856 | * pool - buffer pool number |
---|
1857 | * block_size - block size for which buffer pool is configured returned |
---|
1858 | * there |
---|
1859 | * blocks - number of buffers in buffer pool returned there |
---|
1860 | * |
---|
1861 | * RETURNS: |
---|
1862 | * RTEMS status code: RTEMS_SUCCESSFUL if operation completed successfully, |
---|
1863 | * RTEMS_INVALID_NUMBER if appropriate buffer pool is not configured. |
---|
1864 | * |
---|
1865 | * NOTE: |
---|
1866 | * Buffer pools enumerated contiguously starting from 0. |
---|
1867 | */ |
---|
1868 | rtems_status_code |
---|
1869 | rtems_bdbuf_get_pool_info(rtems_bdpool_id pool, int *block_size, |
---|
1870 | int *blocks) |
---|
1871 | { |
---|
1872 | if (pool >= rtems_bdbuf_ctx.npools) |
---|
1873 | return RTEMS_INVALID_NUMBER; |
---|
1874 | |
---|
1875 | if (block_size != NULL) |
---|
1876 | { |
---|
1877 | *block_size = rtems_bdbuf_ctx.pool[pool].blksize; |
---|
1878 | } |
---|
1879 | |
---|
1880 | if (blocks != NULL) |
---|
1881 | { |
---|
1882 | *blocks = rtems_bdbuf_ctx.pool[pool].nblks; |
---|
1883 | } |
---|
1884 | |
---|
1885 | return RTEMS_SUCCESSFUL; |
---|
1886 | } |
---|