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Linux 2.6.35-rc4
[linux-2.6/next.git] / drivers / mtd / sm_ftl.c
blob67822cf6c025387a1791495a103aca7b2a8e1486
1 /*
2 * Copyright © 2009 - Maxim Levitsky
3 * SmartMedia/xD translation layer
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/random.h>
13 #include <linux/hdreg.h>
14 #include <linux/kthread.h>
15 #include <linux/freezer.h>
16 #include <linux/sysfs.h>
17 #include <linux/bitops.h>
18 #include <linux/slab.h>
19 #include <linux/mtd/nand_ecc.h>
20 #include "nand/sm_common.h"
21 #include "sm_ftl.h"
22
23
24
25 struct workqueue_struct *cache_flush_workqueue;
26
27 static int cache_timeout = 1000;
28 module_param(cache_timeout, bool, S_IRUGO);
29 MODULE_PARM_DESC(cache_timeout,
30 "Timeout (in ms) for cache flush (1000 ms default");
31
32 static int debug;
33 module_param(debug, int, S_IRUGO | S_IWUSR);
34 MODULE_PARM_DESC(debug, "Debug level (0-2)");
35
36
37 /* ------------------- sysfs attributtes ---------------------------------- */
38 struct sm_sysfs_attribute {
39 struct device_attribute dev_attr;
40 char *data;
41 int len;
42 };
43
44 ssize_t sm_attr_show(struct device *dev, struct device_attribute *attr,
45 char *buf)
46 {
47 struct sm_sysfs_attribute *sm_attr =
48 container_of(attr, struct sm_sysfs_attribute, dev_attr);
49
50 strncpy(buf, sm_attr->data, sm_attr->len);
51 return sm_attr->len;
52 }
53
54
55 #define NUM_ATTRIBUTES 1
56 #define SM_CIS_VENDOR_OFFSET 0x59
57 struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl)
58 {
59 struct attribute_group *attr_group;
60 struct attribute **attributes;
61 struct sm_sysfs_attribute *vendor_attribute;
62
63 int vendor_len = strnlen(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET,
64 SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET);
65
66 char *vendor = kmalloc(vendor_len, GFP_KERNEL);
67 memcpy(vendor, ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, vendor_len);
68 vendor[vendor_len] = 0;
69
70 /* Initialize sysfs attributes */
71 vendor_attribute =
72 kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL);
73
74 sysfs_attr_init(&vendor_attribute->dev_attr.attr);
75
76 vendor_attribute->data = vendor;
77 vendor_attribute->len = vendor_len;
78 vendor_attribute->dev_attr.attr.name = "vendor";
79 vendor_attribute->dev_attr.attr.mode = S_IRUGO;
80 vendor_attribute->dev_attr.show = sm_attr_show;
81
82
83 /* Create array of pointers to the attributes */
84 attributes = kzalloc(sizeof(struct attribute *) * (NUM_ATTRIBUTES + 1),
85 GFP_KERNEL);
86 attributes[0] = &vendor_attribute->dev_attr.attr;
87
88 /* Finally create the attribute group */
89 attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL);
90 attr_group->attrs = attributes;
91 return attr_group;
92 }
93
94 void sm_delete_sysfs_attributes(struct sm_ftl *ftl)
95 {
96 struct attribute **attributes = ftl->disk_attributes->attrs;
97 int i;
98
99 for (i = 0; attributes[i] ; i++) {
100
101 struct device_attribute *dev_attr = container_of(attributes[i],
102 struct device_attribute, attr);
103
104 struct sm_sysfs_attribute *sm_attr =
105 container_of(dev_attr,
106 struct sm_sysfs_attribute, dev_attr);
107
108 kfree(sm_attr->data);
109 kfree(sm_attr);
110 }
111
112 kfree(ftl->disk_attributes->attrs);
113 kfree(ftl->disk_attributes);
114 }
115
116
117 /* ----------------------- oob helpers -------------------------------------- */
118
119 static int sm_get_lba(uint8_t *lba)
120 {
121 /* check fixed bits */
122 if ((lba[0] & 0xF8) != 0x10)
123 return -2;
124
125 /* check parity - endianess doesn't matter */
126 if (hweight16(*(uint16_t *)lba) & 1)
127 return -2;
128
129 return (lba[1] >> 1) | ((lba[0] & 0x07) << 7);
130 }
131
132
133 /*
134 * Read LBA asscociated with block
135 * returns -1, if block is erased
136 * returns -2 if error happens
137 */
138 static int sm_read_lba(struct sm_oob *oob)
139 {
140 static const uint32_t erased_pattern[4] = {
141 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
142
143 uint16_t lba_test;
144 int lba;
145
146 /* First test for erased block */
147 if (!memcmp(oob, erased_pattern, SM_OOB_SIZE))
148 return -1;
149
150 /* Now check is both copies of the LBA differ too much */
151 lba_test = *(uint16_t *)oob->lba_copy1 ^ *(uint16_t*)oob->lba_copy2;
152 if (lba_test && !is_power_of_2(lba_test))
153 return -2;
154
155 /* And read it */
156 lba = sm_get_lba(oob->lba_copy1);
157
158 if (lba == -2)
159 lba = sm_get_lba(oob->lba_copy2);
160
161 return lba;
162 }
163
164 static void sm_write_lba(struct sm_oob *oob, uint16_t lba)
165 {
166 uint8_t tmp[2];
167
168 WARN_ON(lba >= 1000);
169
170 tmp[0] = 0x10 | ((lba >> 7) & 0x07);
171 tmp[1] = (lba << 1) & 0xFF;
172
173 if (hweight16(*(uint16_t *)tmp) & 0x01)
174 tmp[1] |= 1;
175
176 oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0];
177 oob->lba_copy1[1] = oob->lba_copy2[1] = tmp[1];
178 }
179
180
181 /* Make offset from parts */
182 static loff_t sm_mkoffset(struct sm_ftl *ftl, int zone, int block, int boffset)
183 {
184 WARN_ON(boffset & (SM_SECTOR_SIZE - 1));
185 WARN_ON(zone < 0 || zone >= ftl->zone_count);
186 WARN_ON(block >= ftl->zone_size);
187 WARN_ON(boffset >= ftl->block_size);
188
189 if (block == -1)
190 return -1;
191
192 return (zone * SM_MAX_ZONE_SIZE + block) * ftl->block_size + boffset;
193 }
194
195 /* Breaks offset into parts */
196 static void sm_break_offset(struct sm_ftl *ftl, loff_t offset,
197 int *zone, int *block, int *boffset)
198 {
199 *boffset = do_div(offset, ftl->block_size);
200 *block = do_div(offset, ftl->max_lba);
201 *zone = offset >= ftl->zone_count ? -1 : offset;
202 }
203
204 /* ---------------------- low level IO ------------------------------------- */
205
206 static int sm_correct_sector(uint8_t *buffer, struct sm_oob *oob)
207 {
208 uint8_t ecc[3];
209
210 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc);
211 if (__nand_correct_data(buffer, ecc, oob->ecc1, SM_SMALL_PAGE) < 0)
212 return -EIO;
213
214 buffer += SM_SMALL_PAGE;
215
216 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc);
217 if (__nand_correct_data(buffer, ecc, oob->ecc2, SM_SMALL_PAGE) < 0)
218 return -EIO;
219 return 0;
220 }
221
222 /* Reads a sector + oob*/
223 static int sm_read_sector(struct sm_ftl *ftl,
224 int zone, int block, int boffset,
225 uint8_t *buffer, struct sm_oob *oob)
226 {
227 struct mtd_info *mtd = ftl->trans->mtd;
228 struct mtd_oob_ops ops;
229 struct sm_oob tmp_oob;
230 int ret = -EIO;
231 int try = 0;
232
233 /* FTL can contain -1 entries that are by default filled with bits */
234 if (block == -1) {
235 memset(buffer, 0xFF, SM_SECTOR_SIZE);
236 return 0;
237 }
238
239 /* User might not need the oob, but we do for data vertification */
240 if (!oob)
241 oob = &tmp_oob;
242
243 ops.mode = ftl->smallpagenand ? MTD_OOB_RAW : MTD_OOB_PLACE;
244 ops.ooboffs = 0;
245 ops.ooblen = SM_OOB_SIZE;
246 ops.oobbuf = (void *)oob;
247 ops.len = SM_SECTOR_SIZE;
248 ops.datbuf = buffer;
249
250 again:
251 if (try++) {
252 /* Avoid infinite recursion on CIS reads, sm_recheck_media
253 won't help anyway */
254 if (zone == 0 && block == ftl->cis_block && boffset ==
255 ftl->cis_boffset)
256 return ret;
257
258 /* Test if media is stable */
259 if (try == 3 || sm_recheck_media(ftl))
260 return ret;
261 }
262
263 /* Unfortunelly, oob read will _always_ succeed,
264 despite card removal..... */
265 ret = mtd->read_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops);
266
267 /* Test for unknown errors */
268 if (ret != 0 && ret != -EUCLEAN && ret != -EBADMSG) {
269 dbg("read of block %d at zone %d, failed due to error (%d)",
270 block, zone, ret);
271 goto again;
272 }
273
274 /* Do a basic test on the oob, to guard against returned garbage */
275 if (oob->reserved != 0xFFFFFFFF && !is_power_of_2(~oob->reserved))
276 goto again;
277
278 /* This should never happen, unless there is a bug in the mtd driver */
279 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
280 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
281
282 if (!buffer)
283 return 0;
284
285 /* Test if sector marked as bad */
286 if (!sm_sector_valid(oob)) {
287 dbg("read of block %d at zone %d, failed because it is marked"
288 " as bad" , block, zone);
289 goto again;
290 }
291
292 /* Test ECC*/
293 if (ret == -EBADMSG ||
294 (ftl->smallpagenand && sm_correct_sector(buffer, oob))) {
295
296 dbg("read of block %d at zone %d, failed due to ECC error",
297 block, zone);
298 goto again;
299 }
300
301 return 0;
302 }
303
304 /* Writes a sector to media */
305 static int sm_write_sector(struct sm_ftl *ftl,
306 int zone, int block, int boffset,
307 uint8_t *buffer, struct sm_oob *oob)
308 {
309 struct mtd_oob_ops ops;
310 struct mtd_info *mtd = ftl->trans->mtd;
311 int ret;
312
313 BUG_ON(ftl->readonly);
314
315 if (zone == 0 && (block == ftl->cis_block || block == 0)) {
316 dbg("attempted to write the CIS!");
317 return -EIO;
318 }
319
320 if (ftl->unstable)
321 return -EIO;
322
323 ops.mode = ftl->smallpagenand ? MTD_OOB_RAW : MTD_OOB_PLACE;
324 ops.len = SM_SECTOR_SIZE;
325 ops.datbuf = buffer;
326 ops.ooboffs = 0;
327 ops.ooblen = SM_OOB_SIZE;
328 ops.oobbuf = (void *)oob;
329
330 ret = mtd->write_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops);
331
332 /* Now we assume that hardware will catch write bitflip errors */
333 /* If you are paranoid, use CONFIG_MTD_NAND_VERIFY_WRITE */
334
335 if (ret) {
336 dbg("write to block %d at zone %d, failed with error %d",
337 block, zone, ret);
338
339 sm_recheck_media(ftl);
340 return ret;
341 }
342
343 /* This should never happen, unless there is a bug in the driver */
344 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
345 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
346
347 return 0;
348 }
349
350 /* ------------------------ block IO ------------------------------------- */
351
352 /* Write a block using data and lba, and invalid sector bitmap */
353 static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf,
354 int zone, int block, int lba,
355 unsigned long invalid_bitmap)
356 {
357 struct sm_oob oob;
358 int boffset;
359 int retry = 0;
360
361 /* Initialize the oob with requested values */
362 memset(&oob, 0xFF, SM_OOB_SIZE);
363 sm_write_lba(&oob, lba);
364 restart:
365 if (ftl->unstable)
366 return -EIO;
367
368 for (boffset = 0; boffset < ftl->block_size;
369 boffset += SM_SECTOR_SIZE) {
370
371 oob.data_status = 0xFF;
372
373 if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) {
374
375 sm_printk("sector %d of block at LBA %d of zone %d"
376 " coudn't be read, marking it as invalid",
377 boffset / SM_SECTOR_SIZE, lba, zone);
378
379 oob.data_status = 0;
380 }
381
382 if (ftl->smallpagenand) {
383 __nand_calculate_ecc(buf + boffset,
384 SM_SMALL_PAGE, oob.ecc1);
385
386 __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE,
387 SM_SMALL_PAGE, oob.ecc2);
388 }
389 if (!sm_write_sector(ftl, zone, block, boffset,
390 buf + boffset, &oob))
391 continue;
392
393 if (!retry) {
394
395 /* If write fails. try to erase the block */
396 /* This is safe, because we never write in blocks
397 that contain valuable data.
398 This is intended to repair block that are marked
399 as erased, but that isn't fully erased*/
400
401 if (sm_erase_block(ftl, zone, block, 0))
402 return -EIO;
403
404 retry = 1;
405 goto restart;
406 } else {
407 sm_mark_block_bad(ftl, zone, block);
408 return -EIO;
409 }
410 }
411 return 0;
412 }
413
414
415 /* Mark whole block at offset 'offs' as bad. */
416 static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block)
417 {
418 struct sm_oob oob;
419 int boffset;
420
421 memset(&oob, 0xFF, SM_OOB_SIZE);
422 oob.block_status = 0xF0;
423
424 if (ftl->unstable)
425 return;
426
427 if (sm_recheck_media(ftl))
428 return;
429
430 sm_printk("marking block %d of zone %d as bad", block, zone);
431
432 /* We aren't checking the return value, because we don't care */
433 /* This also fails on fake xD cards, but I guess these won't expose
434 any bad blocks till fail completly */
435 for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE)
436 sm_write_sector(ftl, zone, block, boffset, NULL, &oob);
437 }
438
439 /*
440 * Erase a block within a zone
441 * If erase succedes, it updates free block fifo, otherwise marks block as bad
442 */
443 static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block,
444 int put_free)
445 {
446 struct ftl_zone *zone = &ftl->zones[zone_num];
447 struct mtd_info *mtd = ftl->trans->mtd;
448 struct erase_info erase;
449
450 erase.mtd = mtd;
451 erase.callback = sm_erase_callback;
452 erase.addr = sm_mkoffset(ftl, zone_num, block, 0);
453 erase.len = ftl->block_size;
454 erase.priv = (u_long)ftl;
455
456 if (ftl->unstable)
457 return -EIO;
458
459 BUG_ON(ftl->readonly);
460
461 if (zone_num == 0 && (block == ftl->cis_block || block == 0)) {
462 sm_printk("attempted to erase the CIS!");
463 return -EIO;
464 }
465
466 if (mtd->erase(mtd, &erase)) {
467 sm_printk("erase of block %d in zone %d failed",
468 block, zone_num);
469 goto error;
470 }
471
472 if (erase.state == MTD_ERASE_PENDING)
473 wait_for_completion(&ftl->erase_completion);
474
475 if (erase.state != MTD_ERASE_DONE) {
476 sm_printk("erase of block %d in zone %d failed after wait",
477 block, zone_num);
478 goto error;
479 }
480
481 if (put_free)
482 kfifo_in(&zone->free_sectors,
483 (const unsigned char *)&block, sizeof(block));
484
485 return 0;
486 error:
487 sm_mark_block_bad(ftl, zone_num, block);
488 return -EIO;
489 }
490
491 static void sm_erase_callback(struct erase_info *self)
492 {
493 struct sm_ftl *ftl = (struct sm_ftl *)self->priv;
494 complete(&ftl->erase_completion);
495 }
496
497 /* Throughtly test that block is valid. */
498 static int sm_check_block(struct sm_ftl *ftl, int zone, int block)
499 {
500 int boffset;
501 struct sm_oob oob;
502 int lbas[] = { -3, 0, 0, 0 };
503 int i = 0;
504 int test_lba;
505
506
507 /* First just check that block doesn't look fishy */
508 /* Only blocks that are valid or are sliced in two parts, are
509 accepted */
510 for (boffset = 0; boffset < ftl->block_size;
511 boffset += SM_SECTOR_SIZE) {
512
513 /* This shoudn't happen anyway */
514 if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob))
515 return -2;
516
517 test_lba = sm_read_lba(&oob);
518
519 if (lbas[i] != test_lba)
520 lbas[++i] = test_lba;
521
522 /* If we found three different LBAs, something is fishy */
523 if (i == 3)
524 return -EIO;
525 }
526
527 /* If the block is sliced (partialy erased usually) erase it */
528 if (i == 2) {
529 sm_erase_block(ftl, zone, block, 1);
530 return 1;
531 }
532
533 return 0;
534 }
535
536 /* ----------------- media scanning --------------------------------- */
537 static const struct chs_entry chs_table[] = {
538 { 1, 125, 4, 4 },
539 { 2, 125, 4, 8 },
540 { 4, 250, 4, 8 },
541 { 8, 250, 4, 16 },
542 { 16, 500, 4, 16 },
543 { 32, 500, 8, 16 },
544 { 64, 500, 8, 32 },
545 { 128, 500, 16, 32 },
546 { 256, 1000, 16, 32 },
547 { 512, 1015, 32, 63 },
548 { 1024, 985, 33, 63 },
549 { 2048, 985, 33, 63 },
550 { 0 },
551 };
552
553
554 static const uint8_t cis_signature[] = {
555 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
556 };
557 /* Find out media parameters.
558 * This ideally has to be based on nand id, but for now device size is enough */
559 int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd)
560 {
561 int i;
562 int size_in_megs = mtd->size / (1024 * 1024);
563
564 ftl->readonly = mtd->type == MTD_ROM;
565
566 /* Manual settings for very old devices */
567 ftl->zone_count = 1;
568 ftl->smallpagenand = 0;
569
570 switch (size_in_megs) {
571 case 1:
572 /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/
573 ftl->zone_size = 256;
574 ftl->max_lba = 250;
575 ftl->block_size = 8 * SM_SECTOR_SIZE;
576 ftl->smallpagenand = 1;
577
578 break;
579 case 2:
580 /* 2 MiB flash SmartMedia (256 byte pages)*/
581 if (mtd->writesize == SM_SMALL_PAGE) {
582 ftl->zone_size = 512;
583 ftl->max_lba = 500;
584 ftl->block_size = 8 * SM_SECTOR_SIZE;
585 ftl->smallpagenand = 1;
586 /* 2 MiB rom SmartMedia */
587 } else {
588
589 if (!ftl->readonly)
590 return -ENODEV;
591
592 ftl->zone_size = 256;
593 ftl->max_lba = 250;
594 ftl->block_size = 16 * SM_SECTOR_SIZE;
595 }
596 break;
597 case 4:
598 /* 4 MiB flash/rom SmartMedia device */
599 ftl->zone_size = 512;
600 ftl->max_lba = 500;
601 ftl->block_size = 16 * SM_SECTOR_SIZE;
602 break;
603 case 8:
604 /* 8 MiB flash/rom SmartMedia device */
605 ftl->zone_size = 1024;
606 ftl->max_lba = 1000;
607 ftl->block_size = 16 * SM_SECTOR_SIZE;
608 }
609
610 /* Minimum xD size is 16MiB. Also, all xD cards have standard zone
611 sizes. SmartMedia cards exist up to 128 MiB and have same layout*/
612 if (size_in_megs >= 16) {
613 ftl->zone_count = size_in_megs / 16;
614 ftl->zone_size = 1024;
615 ftl->max_lba = 1000;
616 ftl->block_size = 32 * SM_SECTOR_SIZE;
617 }
618
619 /* Test for proper write,erase and oob sizes */
620 if (mtd->erasesize > ftl->block_size)
621 return -ENODEV;
622
623 if (mtd->writesize > SM_SECTOR_SIZE)
624 return -ENODEV;
625
626 if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE)
627 return -ENODEV;
628
629 if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE)
630 return -ENODEV;
631
632 /* We use these functions for IO */
633 if (!mtd->read_oob || !mtd->write_oob)
634 return -ENODEV;
635
636 /* Find geometry information */
637 for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) {
638 if (chs_table[i].size == size_in_megs) {
639 ftl->cylinders = chs_table[i].cyl;
640 ftl->heads = chs_table[i].head;
641 ftl->sectors = chs_table[i].sec;
642 return 0;
643 }
644 }
645
646 sm_printk("media has unknown size : %dMiB", size_in_megs);
647 ftl->cylinders = 985;
648 ftl->heads = 33;
649 ftl->sectors = 63;
650 return 0;
651 }
652
653 /* Validate the CIS */
654 static int sm_read_cis(struct sm_ftl *ftl)
655 {
656 struct sm_oob oob;
657
658 if (sm_read_sector(ftl,
659 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob))
660 return -EIO;
661
662 if (!sm_sector_valid(&oob) || !sm_block_valid(&oob))
663 return -EIO;
664
665 if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset,
666 cis_signature, sizeof(cis_signature))) {
667 return 0;
668 }
669
670 return -EIO;
671 }
672
673 /* Scan the media for the CIS */
674 static int sm_find_cis(struct sm_ftl *ftl)
675 {
676 struct sm_oob oob;
677 int block, boffset;
678 int block_found = 0;
679 int cis_found = 0;
680
681 /* Search for first valid block */
682 for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) {
683
684 if (sm_read_sector(ftl, 0, block, 0, NULL, &oob))
685 continue;
686
687 if (!sm_block_valid(&oob))
688 continue;
689 block_found = 1;
690 break;
691 }
692
693 if (!block_found)
694 return -EIO;
695
696 /* Search for first valid sector in this block */
697 for (boffset = 0 ; boffset < ftl->block_size;
698 boffset += SM_SECTOR_SIZE) {
699
700 if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob))
701 continue;
702
703 if (!sm_sector_valid(&oob))
704 continue;
705 break;
706 }
707
708 if (boffset == ftl->block_size)
709 return -EIO;
710
711 ftl->cis_block = block;
712 ftl->cis_boffset = boffset;
713 ftl->cis_page_offset = 0;
714
715 cis_found = !sm_read_cis(ftl);
716
717 if (!cis_found) {
718 ftl->cis_page_offset = SM_SMALL_PAGE;
719 cis_found = !sm_read_cis(ftl);
720 }
721
722 if (cis_found) {
723 dbg("CIS block found at offset %x",
724 block * ftl->block_size +
725 boffset + ftl->cis_page_offset);
726 return 0;
727 }
728 return -EIO;
729 }
730
731 /* Basic test to determine if underlying mtd device if functional */
732 static int sm_recheck_media(struct sm_ftl *ftl)
733 {
734 if (sm_read_cis(ftl)) {
735
736 if (!ftl->unstable) {
737 sm_printk("media unstable, not allowing writes");
738 ftl->unstable = 1;
739 }
740 return -EIO;
741 }
742 return 0;
743 }
744
745 /* Initialize a FTL zone */
746 static int sm_init_zone(struct sm_ftl *ftl, int zone_num)
747 {
748 struct ftl_zone *zone = &ftl->zones[zone_num];
749 struct sm_oob oob;
750 uint16_t block;
751 int lba;
752 int i = 0;
753 int len;
754
755 dbg("initializing zone %d", zone_num);
756
757 /* Allocate memory for FTL table */
758 zone->lba_to_phys_table = kmalloc(ftl->max_lba * 2, GFP_KERNEL);
759
760 if (!zone->lba_to_phys_table)
761 return -ENOMEM;
762 memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2);
763
764
765 /* Allocate memory for free sectors FIFO */
766 if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) {
767 kfree(zone->lba_to_phys_table);
768 return -ENOMEM;
769 }
770
771 /* Now scan the zone */
772 for (block = 0 ; block < ftl->zone_size ; block++) {
773
774 /* Skip blocks till the CIS (including) */
775 if (zone_num == 0 && block <= ftl->cis_block)
776 continue;
777
778 /* Read the oob of first sector */
779 if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob))
780 return -EIO;
781
782 /* Test to see if block is erased. It is enough to test
783 first sector, because erase happens in one shot */
784 if (sm_block_erased(&oob)) {
785 kfifo_in(&zone->free_sectors,
786 (unsigned char *)&block, 2);
787 continue;
788 }
789
790 /* If block is marked as bad, skip it */
791 /* This assumes we can trust first sector*/
792 /* However the way the block valid status is defined, ensures
793 very low probability of failure here */
794 if (!sm_block_valid(&oob)) {
795 dbg("PH %04d <-> <marked bad>", block);
796 continue;
797 }
798
799
800 lba = sm_read_lba(&oob);
801
802 /* Invalid LBA means that block is damaged. */
803 /* We can try to erase it, or mark it as bad, but
804 lets leave that to recovery application */
805 if (lba == -2 || lba >= ftl->max_lba) {
806 dbg("PH %04d <-> LBA %04d(bad)", block, lba);
807 continue;
808 }
809
810
811 /* If there is no collision,
812 just put the sector in the FTL table */
813 if (zone->lba_to_phys_table[lba] < 0) {
814 dbg_verbose("PH %04d <-> LBA %04d", block, lba);
815 zone->lba_to_phys_table[lba] = block;
816 continue;
817 }
818
819 sm_printk("collision"
820 " of LBA %d between blocks %d and %d in zone %d",
821 lba, zone->lba_to_phys_table[lba], block, zone_num);
822
823 /* Test that this block is valid*/
824 if (sm_check_block(ftl, zone_num, block))
825 continue;
826
827 /* Test now the old block */
828 if (sm_check_block(ftl, zone_num,
829 zone->lba_to_phys_table[lba])) {
830 zone->lba_to_phys_table[lba] = block;
831 continue;
832 }
833
834 /* If both blocks are valid and share same LBA, it means that
835 they hold different versions of same data. It not
836 known which is more recent, thus just erase one of them
837 */
838 sm_printk("both blocks are valid, erasing the later");
839 sm_erase_block(ftl, zone_num, block, 1);
840 }
841
842 dbg("zone initialized");
843 zone->initialized = 1;
844
845 /* No free sectors, means that the zone is heavily damaged, write won't
846 work, but it can still can be (partially) read */
847 if (!kfifo_len(&zone->free_sectors)) {
848 sm_printk("no free blocks in zone %d", zone_num);
849 return 0;
850 }
851
852 /* Randomize first block we write to */
853 get_random_bytes(&i, 2);
854 i %= (kfifo_len(&zone->free_sectors) / 2);
855
856 while (i--) {
857 len = kfifo_out(&zone->free_sectors,
858 (unsigned char *)&block, 2);
859 WARN_ON(len != 2);
860 kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
861 }
862 return 0;
863 }
864
865 /* Get and automaticly initialize an FTL mapping for one zone */
866 struct ftl_zone *sm_get_zone(struct sm_ftl *ftl, int zone_num)
867 {
868 struct ftl_zone *zone;
869 int error;
870
871 BUG_ON(zone_num >= ftl->zone_count);
872 zone = &ftl->zones[zone_num];
873
874 if (!zone->initialized) {
875 error = sm_init_zone(ftl, zone_num);
876
877 if (error)
878 return ERR_PTR(error);
879 }
880 return zone;
881 }
882
883
884 /* ----------------- cache handling ------------------------------------------*/
885
886 /* Initialize the one block cache */
887 void sm_cache_init(struct sm_ftl *ftl)
888 {
889 ftl->cache_data_invalid_bitmap = 0xFFFFFFFF;
890 ftl->cache_clean = 1;
891 ftl->cache_zone = -1;
892 ftl->cache_block = -1;
893 /*memset(ftl->cache_data, 0xAA, ftl->block_size);*/
894 }
895
896 /* Put sector in one block cache */
897 void sm_cache_put(struct sm_ftl *ftl, char *buffer, int boffset)
898 {
899 memcpy(ftl->cache_data + boffset, buffer, SM_SECTOR_SIZE);
900 clear_bit(boffset / SM_SECTOR_SIZE, &ftl->cache_data_invalid_bitmap);
901 ftl->cache_clean = 0;
902 }
903
904 /* Read a sector from the cache */
905 int sm_cache_get(struct sm_ftl *ftl, char *buffer, int boffset)
906 {
907 if (test_bit(boffset / SM_SECTOR_SIZE,
908 &ftl->cache_data_invalid_bitmap))
909 return -1;
910
911 memcpy(buffer, ftl->cache_data + boffset, SM_SECTOR_SIZE);
912 return 0;
913 }
914
915 /* Write the cache to hardware */
916 int sm_cache_flush(struct sm_ftl *ftl)
917 {
918 struct ftl_zone *zone;
919
920 int sector_num;
921 uint16_t write_sector;
922 int zone_num = ftl->cache_zone;
923 int block_num;
924
925 if (ftl->cache_clean)
926 return 0;
927
928 if (ftl->unstable)
929 return -EIO;
930
931 BUG_ON(zone_num < 0);
932 zone = &ftl->zones[zone_num];
933 block_num = zone->lba_to_phys_table[ftl->cache_block];
934
935
936 /* Try to read all unread areas of the cache block*/
937 for_each_set_bit(sector_num, &ftl->cache_data_invalid_bitmap,
938 ftl->block_size / SM_SECTOR_SIZE) {
939
940 if (!sm_read_sector(ftl,
941 zone_num, block_num, sector_num * SM_SECTOR_SIZE,
942 ftl->cache_data + sector_num * SM_SECTOR_SIZE, NULL))
943 clear_bit(sector_num,
944 &ftl->cache_data_invalid_bitmap);
945 }
946 restart:
947
948 if (ftl->unstable)
949 return -EIO;
950
951 /* If there are no spare blocks, */
952 /* we could still continue by erasing/writing the current block,
953 but for such worn out media it doesn't worth the trouble,
954 and the dangers */
955 if (kfifo_out(&zone->free_sectors,
956 (unsigned char *)&write_sector, 2) != 2) {
957 dbg("no free sectors for write!");
958 return -EIO;
959 }
960
961
962 if (sm_write_block(ftl, ftl->cache_data, zone_num, write_sector,
963 ftl->cache_block, ftl->cache_data_invalid_bitmap))
964 goto restart;
965
966 /* Update the FTL table */
967 zone->lba_to_phys_table[ftl->cache_block] = write_sector;
968
969 /* Write succesfull, so erase and free the old block */
970 if (block_num > 0)
971 sm_erase_block(ftl, zone_num, block_num, 1);
972
973 sm_cache_init(ftl);
974 return 0;
975 }
976
977
978 /* flush timer, runs a second after last write */
979 static void sm_cache_flush_timer(unsigned long data)
980 {
981 struct sm_ftl *ftl = (struct sm_ftl *)data;
982 queue_work(cache_flush_workqueue, &ftl->flush_work);
983 }
984
985 /* cache flush work, kicked by timer */
986 static void sm_cache_flush_work(struct work_struct *work)
987 {
988 struct sm_ftl *ftl = container_of(work, struct sm_ftl, flush_work);
989 mutex_lock(&ftl->mutex);
990 sm_cache_flush(ftl);
991 mutex_unlock(&ftl->mutex);
992 return;
993 }
994
995 /* ---------------- outside interface -------------------------------------- */
996
997 /* outside interface: read a sector */
998 static int sm_read(struct mtd_blktrans_dev *dev,
999 unsigned long sect_no, char *buf)
1000 {
1001 struct sm_ftl *ftl = dev->priv;
1002 struct ftl_zone *zone;
1003 int error = 0, in_cache = 0;
1004 int zone_num, block, boffset;
1005
1006 sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset);
1007 mutex_lock(&ftl->mutex);
1008
1009
1010 zone = sm_get_zone(ftl, zone_num);
1011 if (IS_ERR(zone)) {
1012 error = PTR_ERR(zone);
1013 goto unlock;
1014 }
1015
1016 /* Have to look at cache first */
1017 if (ftl->cache_zone == zone_num && ftl->cache_block == block) {
1018 in_cache = 1;
1019 if (!sm_cache_get(ftl, buf, boffset))
1020 goto unlock;
1021 }
1022
1023 /* Translate the block and return if doesn't exist in the table */
1024 block = zone->lba_to_phys_table[block];
1025
1026 if (block == -1) {
1027 memset(buf, 0xFF, SM_SECTOR_SIZE);
1028 goto unlock;
1029 }
1030
1031 if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) {
1032 error = -EIO;
1033 goto unlock;
1034 }
1035
1036 if (in_cache)
1037 sm_cache_put(ftl, buf, boffset);
1038 unlock:
1039 mutex_unlock(&ftl->mutex);
1040 return error;
1041 }
1042
1043 /* outside interface: write a sector */
1044 static int sm_write(struct mtd_blktrans_dev *dev,
1045 unsigned long sec_no, char *buf)
1046 {
1047 struct sm_ftl *ftl = dev->priv;
1048 struct ftl_zone *zone;
1049 int error, zone_num, block, boffset;
1050
1051 BUG_ON(ftl->readonly);
1052 sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset);
1053
1054 /* No need in flush thread running now */
1055 del_timer(&ftl->timer);
1056 mutex_lock(&ftl->mutex);
1057
1058 zone = sm_get_zone(ftl, zone_num);
1059 if (IS_ERR(zone)) {
1060 error = PTR_ERR(zone);
1061 goto unlock;
1062 }
1063
1064 /* If entry is not in cache, flush it */
1065 if (ftl->cache_block != block || ftl->cache_zone != zone_num) {
1066
1067 error = sm_cache_flush(ftl);
1068 if (error)
1069 goto unlock;
1070
1071 ftl->cache_block = block;
1072 ftl->cache_zone = zone_num;
1073 }
1074
1075 sm_cache_put(ftl, buf, boffset);
1076 unlock:
1077 mod_timer(&ftl->timer, jiffies + msecs_to_jiffies(cache_timeout));
1078 mutex_unlock(&ftl->mutex);
1079 return error;
1080 }
1081
1082 /* outside interface: flush everything */
1083 static int sm_flush(struct mtd_blktrans_dev *dev)
1084 {
1085 struct sm_ftl *ftl = dev->priv;
1086 int retval;
1087
1088 mutex_lock(&ftl->mutex);
1089 retval = sm_cache_flush(ftl);
1090 mutex_unlock(&ftl->mutex);
1091 return retval;
1092 }
1093
1094 /* outside interface: device is released */
1095 static int sm_release(struct mtd_blktrans_dev *dev)
1096 {
1097 struct sm_ftl *ftl = dev->priv;
1098
1099 mutex_lock(&ftl->mutex);
1100 del_timer_sync(&ftl->timer);
1101 cancel_work_sync(&ftl->flush_work);
1102 sm_cache_flush(ftl);
1103 mutex_unlock(&ftl->mutex);
1104 return 0;
1105 }
1106
1107 /* outside interface: get geometry */
1108 static int sm_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
1109 {
1110 struct sm_ftl *ftl = dev->priv;
1111 geo->heads = ftl->heads;
1112 geo->sectors = ftl->sectors;
1113 geo->cylinders = ftl->cylinders;
1114 return 0;
1115 }
1116
1117 /* external interface: main initialization function */
1118 static void sm_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
1119 {
1120 struct mtd_blktrans_dev *trans;
1121 struct sm_ftl *ftl;
1122
1123 /* Allocate & initialize our private structure */
1124 ftl = kzalloc(sizeof(struct sm_ftl), GFP_KERNEL);
1125 if (!ftl)
1126 goto error1;
1127
1128
1129 mutex_init(&ftl->mutex);
1130 setup_timer(&ftl->timer, sm_cache_flush_timer, (unsigned long)ftl);
1131 INIT_WORK(&ftl->flush_work, sm_cache_flush_work);
1132 init_completion(&ftl->erase_completion);
1133
1134 /* Read media information */
1135 if (sm_get_media_info(ftl, mtd)) {
1136 dbg("found unsupported mtd device, aborting");
1137 goto error2;
1138 }
1139
1140
1141 /* Allocate temporary CIS buffer for read retry support */
1142 ftl->cis_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
1143 if (!ftl->cis_buffer)
1144 goto error2;
1145
1146 /* Allocate zone array, it will be initialized on demand */
1147 ftl->zones = kzalloc(sizeof(struct ftl_zone) * ftl->zone_count,
1148 GFP_KERNEL);
1149 if (!ftl->zones)
1150 goto error3;
1151
1152 /* Allocate the cache*/
1153 ftl->cache_data = kzalloc(ftl->block_size, GFP_KERNEL);
1154
1155 if (!ftl->cache_data)
1156 goto error4;
1157
1158 sm_cache_init(ftl);
1159
1160
1161 /* Allocate upper layer structure and initialize it */
1162 trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL);
1163 if (!trans)
1164 goto error5;
1165
1166 ftl->trans = trans;
1167 trans->priv = ftl;
1168
1169 trans->tr = tr;
1170 trans->mtd = mtd;
1171 trans->devnum = -1;
1172 trans->size = (ftl->block_size * ftl->max_lba * ftl->zone_count) >> 9;
1173 trans->readonly = ftl->readonly;
1174
1175 if (sm_find_cis(ftl)) {
1176 dbg("CIS not found on mtd device, aborting");
1177 goto error6;
1178 }
1179
1180 ftl->disk_attributes = sm_create_sysfs_attributes(ftl);
1181 trans->disk_attributes = ftl->disk_attributes;
1182
1183 sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d",
1184 (int)(mtd->size / (1024 * 1024)), mtd->index);
1185
1186 dbg("FTL layout:");
1187 dbg("%d zone(s), each consists of %d blocks (+%d spares)",
1188 ftl->zone_count, ftl->max_lba,
1189 ftl->zone_size - ftl->max_lba);
1190 dbg("each block consists of %d bytes",
1191 ftl->block_size);
1192
1193
1194 /* Register device*/
1195 if (add_mtd_blktrans_dev(trans)) {
1196 dbg("error in mtdblktrans layer");
1197 goto error6;
1198 }
1199 return;
1200 error6:
1201 kfree(trans);
1202 error5:
1203 kfree(ftl->cache_data);
1204 error4:
1205 kfree(ftl->zones);
1206 error3:
1207 kfree(ftl->cis_buffer);
1208 error2:
1209 kfree(ftl);
1210 error1:
1211 return;
1212 }
1213
1214 /* main interface: device {surprise,} removal */
1215 static void sm_remove_dev(struct mtd_blktrans_dev *dev)
1216 {
1217 struct sm_ftl *ftl = dev->priv;
1218 int i;
1219
1220 del_mtd_blktrans_dev(dev);
1221 ftl->trans = NULL;
1222
1223 for (i = 0 ; i < ftl->zone_count; i++) {
1224
1225 if (!ftl->zones[i].initialized)
1226 continue;
1227
1228 kfree(ftl->zones[i].lba_to_phys_table);
1229 kfifo_free(&ftl->zones[i].free_sectors);
1230 }
1231
1232 sm_delete_sysfs_attributes(ftl);
1233 kfree(ftl->cis_buffer);
1234 kfree(ftl->zones);
1235 kfree(ftl->cache_data);
1236 kfree(ftl);
1237 }
1238
1239 static struct mtd_blktrans_ops sm_ftl_ops = {
1240 .name = "smblk",
1241 .major = -1,
1242 .part_bits = SM_FTL_PARTN_BITS,
1243 .blksize = SM_SECTOR_SIZE,
1244 .getgeo = sm_getgeo,
1245
1246 .add_mtd = sm_add_mtd,
1247 .remove_dev = sm_remove_dev,
1248
1249 .readsect = sm_read,
1250 .writesect = sm_write,
1251
1252 .flush = sm_flush,
1253 .release = sm_release,
1254
1255 .owner = THIS_MODULE,
1256 };
1257
1258 static __init int sm_module_init(void)
1259 {
1260 int error = 0;
1261 cache_flush_workqueue = create_freezeable_workqueue("smflush");
1262
1263 if (IS_ERR(cache_flush_workqueue))
1264 return PTR_ERR(cache_flush_workqueue);
1265
1266 error = register_mtd_blktrans(&sm_ftl_ops);
1267 if (error)
1268 destroy_workqueue(cache_flush_workqueue);
1269 return error;
1270
1271 }
1272
1273 static void __exit sm_module_exit(void)
1274 {
1275 destroy_workqueue(cache_flush_workqueue);
1276 deregister_mtd_blktrans(&sm_ftl_ops);
1277 }
1278
1279 module_init(sm_module_init);
1280 module_exit(sm_module_exit);
1281
1282 MODULE_LICENSE("GPL");
1283 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1284 MODULE_DESCRIPTION("Smartmedia/xD mtd translation layer");
linux-next