1 | /* $NetBSD: rf_aselect.c,v 1.28 2013/09/15 12:11:16 martin Exp $ */ |
2 | /* |
3 | * Copyright (c) 1995 Carnegie-Mellon University. |
4 | * All rights reserved. |
5 | * |
6 | * Author: Mark Holland, William V. Courtright II |
7 | * |
8 | * Permission to use, copy, modify and distribute this software and |
9 | * its documentation is hereby granted, provided that both the copyright |
10 | * notice and this permission notice appear in all copies of the |
11 | * software, derivative works or modified versions, and any portions |
12 | * thereof, and that both notices appear in supporting documentation. |
13 | * |
14 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" |
15 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND |
16 | * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. |
17 | * |
18 | * Carnegie Mellon requests users of this software to return to |
19 | * |
20 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU |
21 | * School of Computer Science |
22 | * Carnegie Mellon University |
23 | * Pittsburgh PA 15213-3890 |
24 | * |
25 | * any improvements or extensions that they make and grant Carnegie the |
26 | * rights to redistribute these changes. |
27 | */ |
28 | |
29 | /***************************************************************************** |
30 | * |
31 | * aselect.c -- algorithm selection code |
32 | * |
33 | *****************************************************************************/ |
34 | |
35 | #include <sys/cdefs.h> |
36 | __KERNEL_RCSID(0, "$NetBSD: rf_aselect.c,v 1.28 2013/09/15 12:11:16 martin Exp $" ); |
37 | |
38 | #include <dev/raidframe/raidframevar.h> |
39 | |
40 | #include "rf_archs.h" |
41 | #include "rf_raid.h" |
42 | #include "rf_dag.h" |
43 | #include "rf_dagutils.h" |
44 | #include "rf_dagfuncs.h" |
45 | #include "rf_general.h" |
46 | #include "rf_desc.h" |
47 | #include "rf_map.h" |
48 | |
49 | static void InitHdrNode(RF_DagHeader_t **, RF_Raid_t *, RF_RaidAccessDesc_t *); |
50 | int rf_SelectAlgorithm(RF_RaidAccessDesc_t *, RF_RaidAccessFlags_t); |
51 | |
52 | /****************************************************************************** |
53 | * |
54 | * Create and Initialiaze a dag header and termination node |
55 | * |
56 | *****************************************************************************/ |
57 | static void |
58 | InitHdrNode(RF_DagHeader_t **hdr, RF_Raid_t *raidPtr, RF_RaidAccessDesc_t *desc) |
59 | { |
60 | /* create and initialize dag hdr */ |
61 | *hdr = rf_AllocDAGHeader(); |
62 | rf_MakeAllocList((*hdr)->allocList); |
63 | (*hdr)->status = rf_enable; |
64 | (*hdr)->numSuccedents = 0; |
65 | (*hdr)->nodes = NULL; |
66 | (*hdr)->raidPtr = raidPtr; |
67 | (*hdr)->next = NULL; |
68 | (*hdr)->desc = desc; |
69 | } |
70 | |
71 | /****************************************************************************** |
72 | * |
73 | * Create a DAG to do a read or write operation. |
74 | * |
75 | * create a list of dagLists, one list per parity stripe. |
76 | * return the lists in the desc->dagList (which is a list of lists). |
77 | * |
78 | * Normally, each list contains one dag for the entire stripe. In some |
79 | * tricky cases, we break this into multiple dags, either one per stripe |
80 | * unit or one per block (sector). When this occurs, these dags are returned |
81 | * as a linked list (dagList) which is executed sequentially (to preserve |
82 | * atomic parity updates in the stripe). |
83 | * |
84 | * dags which operate on independent parity goups (stripes) are returned in |
85 | * independent dagLists (distinct elements in desc->dagArray) and may be |
86 | * executed concurrently. |
87 | * |
88 | * Finally, if the SelectionFunc fails to create a dag for a block, we punt |
89 | * and return 1. |
90 | * |
91 | * The above process is performed in two phases: |
92 | * 1) create an array(s) of creation functions (eg stripeFuncs) |
93 | * 2) create dags and concatenate/merge to form the final dag. |
94 | * |
95 | * Because dag's are basic blocks (single entry, single exit, unconditional |
96 | * control flow, we can add the following optimizations (future work): |
97 | * first-pass optimizer to allow max concurrency (need all data dependencies) |
98 | * second-pass optimizer to eliminate common subexpressions (need true |
99 | * data dependencies) |
100 | * third-pass optimizer to eliminate dead code (need true data dependencies) |
101 | *****************************************************************************/ |
102 | |
103 | int |
104 | rf_SelectAlgorithm(RF_RaidAccessDesc_t *desc, RF_RaidAccessFlags_t flags) |
105 | { |
106 | RF_AccessStripeMapHeader_t *asm_h = desc->asmap; |
107 | RF_IoType_t type = desc->type; |
108 | RF_Raid_t *raidPtr = desc->raidPtr; |
109 | void *bp = desc->bp; |
110 | |
111 | RF_AccessStripeMap_t *asmap = asm_h->stripeMap; |
112 | RF_AccessStripeMap_t *asm_p; |
113 | RF_DagHeader_t *dag_h = NULL, *tempdag_h, *lastdag_h; |
114 | RF_DagList_t *dagList, *dagListend; |
115 | int i, j, k; |
116 | RF_FuncList_t *stripeFuncsList, *stripeFuncs, *stripeFuncsEnd, *temp; |
117 | RF_AccessStripeMap_t *asm_up, *asm_bp; |
118 | RF_AccessStripeMapHeader_t *endASMList; |
119 | RF_ASMHeaderListElem_t *asmhle, *tmpasmhle; |
120 | RF_VoidFunctionPointerListElem_t *vfple, *tmpvfple; |
121 | RF_FailedStripe_t *failed_stripes_list, *failed_stripes_list_end; |
122 | RF_FailedStripe_t *tmpfailed_stripe, *failed_stripe = NULL; |
123 | RF_ASMHeaderListElem_t *failed_stripes_asmh_u_end = NULL; |
124 | RF_ASMHeaderListElem_t *failed_stripes_asmh_b_end = NULL; |
125 | RF_VoidFunctionPointerListElem_t *failed_stripes_vfple_end = NULL; |
126 | RF_VoidFunctionPointerListElem_t *failed_stripes_bvfple_end = NULL; |
127 | RF_VoidFuncPtr uFunc; |
128 | RF_VoidFuncPtr bFunc; |
129 | int numStripesBailed = 0, cantCreateDAGs = RF_FALSE; |
130 | int numStripeUnitsBailed = 0; |
131 | int stripeNum, numUnitDags = 0, stripeUnitNum, numBlockDags = 0; |
132 | RF_StripeNum_t numStripeUnits; |
133 | RF_SectorNum_t numBlocks; |
134 | RF_RaidAddr_t address; |
135 | int length; |
136 | RF_PhysDiskAddr_t *physPtr; |
137 | void *buffer; |
138 | |
139 | lastdag_h = NULL; |
140 | |
141 | stripeFuncsList = NULL; |
142 | stripeFuncsEnd = NULL; |
143 | |
144 | failed_stripes_list = NULL; |
145 | failed_stripes_list_end = NULL; |
146 | |
147 | /* walk through the asm list once collecting information */ |
148 | /* attempt to find a single creation function for each stripe */ |
149 | desc->numStripes = 0; |
150 | for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++) { |
151 | desc->numStripes++; |
152 | stripeFuncs = rf_AllocFuncList(); |
153 | |
154 | if (stripeFuncsEnd == NULL) { |
155 | stripeFuncsList = stripeFuncs; |
156 | } else { |
157 | stripeFuncsEnd->next = stripeFuncs; |
158 | } |
159 | stripeFuncsEnd = stripeFuncs; |
160 | |
161 | (raidPtr->Layout.map->SelectionFunc) (raidPtr, type, asm_p, &(stripeFuncs->fp)); |
162 | /* check to see if we found a creation func for this stripe */ |
163 | if (stripeFuncs->fp == NULL) { |
164 | /* could not find creation function for entire stripe |
165 | * so, let's see if we can find one for each stripe |
166 | * unit in the stripe */ |
167 | |
168 | /* create a failed stripe structure to attempt to deal with the failure */ |
169 | failed_stripe = rf_AllocFailedStripeStruct(); |
170 | if (failed_stripes_list == NULL) { |
171 | failed_stripes_list = failed_stripe; |
172 | failed_stripes_list_end = failed_stripe; |
173 | } else { |
174 | failed_stripes_list_end->next = failed_stripe; |
175 | failed_stripes_list_end = failed_stripe; |
176 | } |
177 | |
178 | /* create an array of creation funcs (called |
179 | * stripeFuncs) for this stripe */ |
180 | numStripeUnits = asm_p->numStripeUnitsAccessed; |
181 | |
182 | /* lookup array of stripeUnitFuncs for this stripe */ |
183 | failed_stripes_asmh_u_end = NULL; |
184 | failed_stripes_vfple_end = NULL; |
185 | for (j = 0, physPtr = asm_p->physInfo; physPtr; physPtr = physPtr->next, j++) { |
186 | /* remap for series of single stripe-unit |
187 | * accesses */ |
188 | address = physPtr->raidAddress; |
189 | length = physPtr->numSector; |
190 | buffer = physPtr->bufPtr; |
191 | |
192 | asmhle = rf_AllocASMHeaderListElem(); |
193 | if (failed_stripe->asmh_u == NULL) { |
194 | failed_stripe->asmh_u = asmhle; /* we're the head... */ |
195 | failed_stripes_asmh_u_end = asmhle; /* and the tail */ |
196 | } else { |
197 | /* tack us onto the end of the list */ |
198 | failed_stripes_asmh_u_end->next = asmhle; |
199 | failed_stripes_asmh_u_end = asmhle; |
200 | } |
201 | |
202 | |
203 | asmhle->asmh = rf_MapAccess(raidPtr, address, length, buffer, RF_DONT_REMAP); |
204 | asm_up = asmhle->asmh->stripeMap; |
205 | |
206 | vfple = rf_AllocVFPListElem(); |
207 | if (failed_stripe->vfple == NULL) { |
208 | failed_stripe->vfple = vfple; |
209 | failed_stripes_vfple_end = vfple; |
210 | } else { |
211 | failed_stripes_vfple_end->next = vfple; |
212 | failed_stripes_vfple_end = vfple; |
213 | } |
214 | |
215 | /* get the creation func for this stripe unit */ |
216 | (raidPtr->Layout.map->SelectionFunc) (raidPtr, type, asm_up, &(vfple->fn)); |
217 | |
218 | /* check to see if we found a creation func |
219 | * for this stripe unit */ |
220 | |
221 | if (vfple->fn == NULL) { |
222 | /* could not find creation function |
223 | * for stripe unit so, let's see if we |
224 | * can find one for each block in the |
225 | * stripe unit */ |
226 | |
227 | numBlocks = physPtr->numSector; |
228 | numBlockDags += numBlocks; |
229 | |
230 | /* lookup array of blockFuncs for this |
231 | * stripe unit */ |
232 | for (k = 0; k < numBlocks; k++) { |
233 | /* remap for series of single |
234 | * stripe-unit accesses */ |
235 | address = physPtr->raidAddress + k; |
236 | length = 1; |
237 | buffer = (char *)physPtr->bufPtr + (k * (1 << raidPtr->logBytesPerSector)); |
238 | |
239 | asmhle = rf_AllocASMHeaderListElem(); |
240 | if (failed_stripe->asmh_b == NULL) { |
241 | failed_stripe->asmh_b = asmhle; |
242 | failed_stripes_asmh_b_end = asmhle; |
243 | } else { |
244 | failed_stripes_asmh_b_end->next = asmhle; |
245 | failed_stripes_asmh_b_end = asmhle; |
246 | } |
247 | |
248 | asmhle->asmh = rf_MapAccess(raidPtr, address, length, buffer, RF_DONT_REMAP); |
249 | asm_bp = asmhle->asmh->stripeMap; |
250 | |
251 | vfple = rf_AllocVFPListElem(); |
252 | if (failed_stripe->bvfple == NULL) { |
253 | failed_stripe->bvfple = vfple; |
254 | failed_stripes_bvfple_end = vfple; |
255 | } else { |
256 | failed_stripes_bvfple_end->next = vfple; |
257 | failed_stripes_bvfple_end = vfple; |
258 | } |
259 | (raidPtr->Layout.map->SelectionFunc) (raidPtr, type, asm_bp, &(vfple->fn)); |
260 | |
261 | /* check to see if we found a |
262 | * creation func for this |
263 | * stripe unit */ |
264 | |
265 | if (vfple->fn == NULL) |
266 | cantCreateDAGs = RF_TRUE; |
267 | } |
268 | numStripeUnitsBailed++; |
269 | } else { |
270 | numUnitDags++; |
271 | } |
272 | } |
273 | RF_ASSERT(j == numStripeUnits); |
274 | numStripesBailed++; |
275 | } |
276 | } |
277 | |
278 | if (cantCreateDAGs) { |
279 | /* free memory and punt */ |
280 | if (numStripesBailed > 0) { |
281 | stripeNum = 0; |
282 | stripeFuncs = stripeFuncsList; |
283 | failed_stripe = failed_stripes_list; |
284 | for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++) { |
285 | if (stripeFuncs->fp == NULL) { |
286 | |
287 | asmhle = failed_stripe->asmh_u; |
288 | while (asmhle) { |
289 | tmpasmhle= asmhle; |
290 | asmhle = tmpasmhle->next; |
291 | rf_FreeAccessStripeMap(tmpasmhle->asmh); |
292 | rf_FreeASMHeaderListElem(tmpasmhle); |
293 | } |
294 | |
295 | asmhle = failed_stripe->asmh_b; |
296 | while (asmhle) { |
297 | tmpasmhle= asmhle; |
298 | asmhle = tmpasmhle->next; |
299 | rf_FreeAccessStripeMap(tmpasmhle->asmh); |
300 | rf_FreeASMHeaderListElem(tmpasmhle); |
301 | } |
302 | |
303 | vfple = failed_stripe->vfple; |
304 | while (vfple) { |
305 | tmpvfple = vfple; |
306 | vfple = tmpvfple->next; |
307 | rf_FreeVFPListElem(tmpvfple); |
308 | } |
309 | |
310 | vfple = failed_stripe->bvfple; |
311 | while (vfple) { |
312 | tmpvfple = vfple; |
313 | vfple = tmpvfple->next; |
314 | rf_FreeVFPListElem(tmpvfple); |
315 | } |
316 | |
317 | stripeNum++; |
318 | /* only move to the next failed stripe slot if the current one was used */ |
319 | tmpfailed_stripe = failed_stripe; |
320 | failed_stripe = failed_stripe->next; |
321 | rf_FreeFailedStripeStruct(tmpfailed_stripe); |
322 | } |
323 | stripeFuncs = stripeFuncs->next; |
324 | } |
325 | RF_ASSERT(stripeNum == numStripesBailed); |
326 | } |
327 | while (stripeFuncsList != NULL) { |
328 | temp = stripeFuncsList; |
329 | stripeFuncsList = stripeFuncsList->next; |
330 | rf_FreeFuncList(temp); |
331 | } |
332 | desc->numStripes = 0; |
333 | return (1); |
334 | } else { |
335 | /* begin dag creation */ |
336 | stripeNum = 0; |
337 | stripeUnitNum = 0; |
338 | |
339 | /* create a list of dagLists and fill them in */ |
340 | |
341 | dagListend = NULL; |
342 | |
343 | stripeFuncs = stripeFuncsList; |
344 | failed_stripe = failed_stripes_list; |
345 | for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++) { |
346 | /* grab dag header for this stripe */ |
347 | dag_h = NULL; |
348 | |
349 | dagList = rf_AllocDAGList(); |
350 | |
351 | /* always tack the new dagList onto the end of the list... */ |
352 | if (dagListend == NULL) { |
353 | desc->dagList = dagList; |
354 | } else { |
355 | dagListend->next = dagList; |
356 | } |
357 | dagListend = dagList; |
358 | |
359 | dagList->desc = desc; |
360 | |
361 | if (stripeFuncs->fp == NULL) { |
362 | /* use bailout functions for this stripe */ |
363 | asmhle = failed_stripe->asmh_u; |
364 | vfple = failed_stripe->vfple; |
365 | /* the following two may contain asm headers and |
366 | block function pointers for multiple asm within |
367 | this access. We initialize tmpasmhle and tmpvfple |
368 | here in order to allow for that, and for correct |
369 | operation below */ |
370 | tmpasmhle = failed_stripe->asmh_b; |
371 | tmpvfple = failed_stripe->bvfple; |
372 | for (j = 0, physPtr = asm_p->physInfo; physPtr; physPtr = physPtr->next, j++) { |
373 | uFunc = vfple->fn; /* stripeUnitFuncs[stripeNum][j]; */ |
374 | if (uFunc == NULL) { |
375 | /* use bailout functions for |
376 | * this stripe unit */ |
377 | for (k = 0; k < physPtr->numSector; k++) { |
378 | /* create a dag for |
379 | * this block */ |
380 | InitHdrNode(&tempdag_h, raidPtr, desc); |
381 | dagList->numDags++; |
382 | if (dag_h == NULL) { |
383 | dag_h = tempdag_h; |
384 | } else { |
385 | lastdag_h->next = tempdag_h; |
386 | } |
387 | lastdag_h = tempdag_h; |
388 | |
389 | bFunc = tmpvfple->fn; /* blockFuncs[stripeUnitNum][k]; */ |
390 | RF_ASSERT(bFunc); |
391 | asm_bp = tmpasmhle->asmh->stripeMap; /* asmh_b[stripeUnitNum][k]->stripeMap; */ |
392 | (*bFunc) (raidPtr, asm_bp, tempdag_h, bp, flags, tempdag_h->allocList); |
393 | |
394 | tmpasmhle = tmpasmhle->next; |
395 | tmpvfple = tmpvfple->next; |
396 | } |
397 | stripeUnitNum++; |
398 | } else { |
399 | /* create a dag for this unit */ |
400 | InitHdrNode(&tempdag_h, raidPtr, desc); |
401 | dagList->numDags++; |
402 | if (dag_h == NULL) { |
403 | dag_h = tempdag_h; |
404 | } else { |
405 | lastdag_h->next = tempdag_h; |
406 | } |
407 | lastdag_h = tempdag_h; |
408 | |
409 | asm_up = asmhle->asmh->stripeMap; /* asmh_u[stripeNum][j]->stripeMap; */ |
410 | (*uFunc) (raidPtr, asm_up, tempdag_h, bp, flags, tempdag_h->allocList); |
411 | } |
412 | asmhle = asmhle->next; |
413 | vfple = vfple->next; |
414 | } |
415 | RF_ASSERT(j == asm_p->numStripeUnitsAccessed); |
416 | /* merge linked bailout dag to existing dag |
417 | * collection */ |
418 | stripeNum++; |
419 | failed_stripe = failed_stripe->next; |
420 | } else { |
421 | /* Create a dag for this parity stripe */ |
422 | InitHdrNode(&tempdag_h, raidPtr, desc); |
423 | dagList->numDags++; |
424 | dag_h = tempdag_h; |
425 | lastdag_h = tempdag_h; |
426 | |
427 | (stripeFuncs->fp) (raidPtr, asm_p, tempdag_h, bp, flags, tempdag_h->allocList); |
428 | } |
429 | dagList->dags = dag_h; |
430 | stripeFuncs = stripeFuncs->next; |
431 | } |
432 | RF_ASSERT(i == desc->numStripes); |
433 | |
434 | /* free memory */ |
435 | if ((numStripesBailed > 0) || (numStripeUnitsBailed > 0)) { |
436 | stripeNum = 0; |
437 | stripeUnitNum = 0; |
438 | /* walk through io, stripe by stripe */ |
439 | /* here we build up dag_h->asmList for this dag... |
440 | we need all of these asm's to do the IO, and |
441 | want them in a convenient place for freeing at a |
442 | later time */ |
443 | stripeFuncs = stripeFuncsList; |
444 | failed_stripe = failed_stripes_list; |
445 | dagList = desc->dagList; |
446 | |
447 | for (i = 0, asm_p = asmap; asm_p; asm_p = asm_p->next, i++) { |
448 | |
449 | dag_h = dagList->dags; |
450 | if (dag_h->asmList) { |
451 | endASMList = dag_h->asmList; |
452 | while (endASMList->next) |
453 | endASMList = endASMList->next; |
454 | } else |
455 | endASMList = NULL; |
456 | |
457 | if (stripeFuncs->fp == NULL) { |
458 | numStripeUnits = asm_p->numStripeUnitsAccessed; |
459 | /* walk through stripe, stripe unit by |
460 | * stripe unit */ |
461 | asmhle = failed_stripe->asmh_u; |
462 | vfple = failed_stripe->vfple; |
463 | /* this contains all of the asm headers for block funcs, |
464 | so we have to initialize this here instead of below.*/ |
465 | tmpasmhle = failed_stripe->asmh_b; |
466 | for (j = 0, physPtr = asm_p->physInfo; physPtr; physPtr = physPtr->next, j++) { |
467 | if (vfple->fn == NULL) { |
468 | numBlocks = physPtr->numSector; |
469 | /* walk through stripe |
470 | * unit, block by |
471 | * block */ |
472 | for (k = 0; k < numBlocks; k++) { |
473 | if (dag_h->asmList == NULL) { |
474 | dag_h->asmList = tmpasmhle->asmh; /* asmh_b[stripeUnitNum][k];*/ |
475 | endASMList = dag_h->asmList; |
476 | } else { |
477 | endASMList->next = tmpasmhle->asmh; |
478 | endASMList = endASMList->next; |
479 | } |
480 | tmpasmhle = tmpasmhle->next; |
481 | } |
482 | stripeUnitNum++; |
483 | } |
484 | if (dag_h->asmList == NULL) { |
485 | dag_h->asmList = asmhle->asmh; |
486 | endASMList = dag_h->asmList; |
487 | } else { |
488 | endASMList->next = asmhle->asmh; |
489 | endASMList = endASMList->next; |
490 | } |
491 | asmhle = asmhle->next; |
492 | vfple = vfple->next; |
493 | } |
494 | stripeNum++; |
495 | failed_stripe = failed_stripe->next; |
496 | } |
497 | dagList = dagList->next; /* need to move in stride with stripeFuncs */ |
498 | stripeFuncs = stripeFuncs->next; |
499 | } |
500 | RF_ASSERT(stripeNum == numStripesBailed); |
501 | RF_ASSERT(stripeUnitNum == numStripeUnitsBailed); |
502 | |
503 | failed_stripe = failed_stripes_list; |
504 | while (failed_stripe) { |
505 | |
506 | asmhle = failed_stripe->asmh_u; |
507 | while (asmhle) { |
508 | tmpasmhle= asmhle; |
509 | asmhle = tmpasmhle->next; |
510 | rf_FreeASMHeaderListElem(tmpasmhle); |
511 | } |
512 | |
513 | asmhle = failed_stripe->asmh_b; |
514 | while (asmhle) { |
515 | tmpasmhle= asmhle; |
516 | asmhle = tmpasmhle->next; |
517 | rf_FreeASMHeaderListElem(tmpasmhle); |
518 | } |
519 | vfple = failed_stripe->vfple; |
520 | while (vfple) { |
521 | tmpvfple = vfple; |
522 | vfple = tmpvfple->next; |
523 | rf_FreeVFPListElem(tmpvfple); |
524 | } |
525 | |
526 | vfple = failed_stripe->bvfple; |
527 | while (vfple) { |
528 | tmpvfple = vfple; |
529 | vfple = tmpvfple->next; |
530 | rf_FreeVFPListElem(tmpvfple); |
531 | } |
532 | |
533 | tmpfailed_stripe = failed_stripe; |
534 | failed_stripe = tmpfailed_stripe->next; |
535 | rf_FreeFailedStripeStruct(tmpfailed_stripe); |
536 | } |
537 | } |
538 | while (stripeFuncsList != NULL) { |
539 | temp = stripeFuncsList; |
540 | stripeFuncsList = stripeFuncsList->next; |
541 | rf_FreeFuncList(temp); |
542 | } |
543 | return (0); |
544 | } |
545 | } |
546 | |