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procfs: Mark create_proc_read_entry deprecated
[linux-2.6.git] / drivers / mtd / sm_ftl.c
blob8dd6ba52404a390c57462bb90f25f470c1d32687
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, int, 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 attributes ---------------------------------- */
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 if (!vendor)
68 goto error1;
69 memcpy(vendor, ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, vendor_len);
70 vendor[vendor_len] = 0;
71
72 /* Initialize sysfs attributes */
73 vendor_attribute =
74 kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL);
75 if (!vendor_attribute)
76 goto error2;
77
78 sysfs_attr_init(&vendor_attribute->dev_attr.attr);
79
80 vendor_attribute->data = vendor;
81 vendor_attribute->len = vendor_len;
82 vendor_attribute->dev_attr.attr.name = "vendor";
83 vendor_attribute->dev_attr.attr.mode = S_IRUGO;
84 vendor_attribute->dev_attr.show = sm_attr_show;
85
86
87 /* Create array of pointers to the attributes */
88 attributes = kzalloc(sizeof(struct attribute *) * (NUM_ATTRIBUTES + 1),
89 GFP_KERNEL);
90 if (!attributes)
91 goto error3;
92 attributes[0] = &vendor_attribute->dev_attr.attr;
93
94 /* Finally create the attribute group */
95 attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL);
96 if (!attr_group)
97 goto error4;
98 attr_group->attrs = attributes;
99 return attr_group;
100 error4:
101 kfree(attributes);
102 error3:
103 kfree(vendor_attribute);
104 error2:
105 kfree(vendor);
106 error1:
107 return NULL;
108 }
109
110 void sm_delete_sysfs_attributes(struct sm_ftl *ftl)
111 {
112 struct attribute **attributes = ftl->disk_attributes->attrs;
113 int i;
114
115 for (i = 0; attributes[i] ; i++) {
116
117 struct device_attribute *dev_attr = container_of(attributes[i],
118 struct device_attribute, attr);
119
120 struct sm_sysfs_attribute *sm_attr =
121 container_of(dev_attr,
122 struct sm_sysfs_attribute, dev_attr);
123
124 kfree(sm_attr->data);
125 kfree(sm_attr);
126 }
127
128 kfree(ftl->disk_attributes->attrs);
129 kfree(ftl->disk_attributes);
130 }
131
132
133 /* ----------------------- oob helpers -------------------------------------- */
134
135 static int sm_get_lba(uint8_t *lba)
136 {
137 /* check fixed bits */
138 if ((lba[0] & 0xF8) != 0x10)
139 return -2;
140
141 /* check parity - endianness doesn't matter */
142 if (hweight16(*(uint16_t *)lba) & 1)
143 return -2;
144
145 return (lba[1] >> 1) | ((lba[0] & 0x07) << 7);
146 }
147
148
149 /*
150 * Read LBA associated with block
151 * returns -1, if block is erased
152 * returns -2 if error happens
153 */
154 static int sm_read_lba(struct sm_oob *oob)
155 {
156 static const uint32_t erased_pattern[4] = {
157 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
158
159 uint16_t lba_test;
160 int lba;
161
162 /* First test for erased block */
163 if (!memcmp(oob, erased_pattern, SM_OOB_SIZE))
164 return -1;
165
166 /* Now check is both copies of the LBA differ too much */
167 lba_test = *(uint16_t *)oob->lba_copy1 ^ *(uint16_t*)oob->lba_copy2;
168 if (lba_test && !is_power_of_2(lba_test))
169 return -2;
170
171 /* And read it */
172 lba = sm_get_lba(oob->lba_copy1);
173
174 if (lba == -2)
175 lba = sm_get_lba(oob->lba_copy2);
176
177 return lba;
178 }
179
180 static void sm_write_lba(struct sm_oob *oob, uint16_t lba)
181 {
182 uint8_t tmp[2];
183
184 WARN_ON(lba >= 1000);
185
186 tmp[0] = 0x10 | ((lba >> 7) & 0x07);
187 tmp[1] = (lba << 1) & 0xFF;
188
189 if (hweight16(*(uint16_t *)tmp) & 0x01)
190 tmp[1] |= 1;
191
192 oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0];
193 oob->lba_copy1[1] = oob->lba_copy2[1] = tmp[1];
194 }
195
196
197 /* Make offset from parts */
198 static loff_t sm_mkoffset(struct sm_ftl *ftl, int zone, int block, int boffset)
199 {
200 WARN_ON(boffset & (SM_SECTOR_SIZE - 1));
201 WARN_ON(zone < 0 || zone >= ftl->zone_count);
202 WARN_ON(block >= ftl->zone_size);
203 WARN_ON(boffset >= ftl->block_size);
204
205 if (block == -1)
206 return -1;
207
208 return (zone * SM_MAX_ZONE_SIZE + block) * ftl->block_size + boffset;
209 }
210
211 /* Breaks offset into parts */
212 static void sm_break_offset(struct sm_ftl *ftl, loff_t offset,
213 int *zone, int *block, int *boffset)
214 {
215 *boffset = do_div(offset, ftl->block_size);
216 *block = do_div(offset, ftl->max_lba);
217 *zone = offset >= ftl->zone_count ? -1 : offset;
218 }
219
220 /* ---------------------- low level IO ------------------------------------- */
221
222 static int sm_correct_sector(uint8_t *buffer, struct sm_oob *oob)
223 {
224 uint8_t ecc[3];
225
226 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc);
227 if (__nand_correct_data(buffer, ecc, oob->ecc1, SM_SMALL_PAGE) < 0)
228 return -EIO;
229
230 buffer += SM_SMALL_PAGE;
231
232 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc);
233 if (__nand_correct_data(buffer, ecc, oob->ecc2, SM_SMALL_PAGE) < 0)
234 return -EIO;
235 return 0;
236 }
237
238 /* Reads a sector + oob*/
239 static int sm_read_sector(struct sm_ftl *ftl,
240 int zone, int block, int boffset,
241 uint8_t *buffer, struct sm_oob *oob)
242 {
243 struct mtd_info *mtd = ftl->trans->mtd;
244 struct mtd_oob_ops ops;
245 struct sm_oob tmp_oob;
246 int ret = -EIO;
247 int try = 0;
248
249 /* FTL can contain -1 entries that are by default filled with bits */
250 if (block == -1) {
251 memset(buffer, 0xFF, SM_SECTOR_SIZE);
252 return 0;
253 }
254
255 /* User might not need the oob, but we do for data verification */
256 if (!oob)
257 oob = &tmp_oob;
258
259 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB;
260 ops.ooboffs = 0;
261 ops.ooblen = SM_OOB_SIZE;
262 ops.oobbuf = (void *)oob;
263 ops.len = SM_SECTOR_SIZE;
264 ops.datbuf = buffer;
265
266 again:
267 if (try++) {
268 /* Avoid infinite recursion on CIS reads, sm_recheck_media
269 won't help anyway */
270 if (zone == 0 && block == ftl->cis_block && boffset ==
271 ftl->cis_boffset)
272 return ret;
273
274 /* Test if media is stable */
275 if (try == 3 || sm_recheck_media(ftl))
276 return ret;
277 }
278
279 /* Unfortunately, oob read will _always_ succeed,
280 despite card removal..... */
281 ret = mtd_read_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops);
282
283 /* Test for unknown errors */
284 if (ret != 0 && !mtd_is_bitflip_or_eccerr(ret)) {
285 dbg("read of block %d at zone %d, failed due to error (%d)",
286 block, zone, ret);
287 goto again;
288 }
289
290 /* Do a basic test on the oob, to guard against returned garbage */
291 if (oob->reserved != 0xFFFFFFFF && !is_power_of_2(~oob->reserved))
292 goto again;
293
294 /* This should never happen, unless there is a bug in the mtd driver */
295 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
296 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
297
298 if (!buffer)
299 return 0;
300
301 /* Test if sector marked as bad */
302 if (!sm_sector_valid(oob)) {
303 dbg("read of block %d at zone %d, failed because it is marked"
304 " as bad" , block, zone);
305 goto again;
306 }
307
308 /* Test ECC*/
309 if (mtd_is_eccerr(ret) ||
310 (ftl->smallpagenand && sm_correct_sector(buffer, oob))) {
311
312 dbg("read of block %d at zone %d, failed due to ECC error",
313 block, zone);
314 goto again;
315 }
316
317 return 0;
318 }
319
320 /* Writes a sector to media */
321 static int sm_write_sector(struct sm_ftl *ftl,
322 int zone, int block, int boffset,
323 uint8_t *buffer, struct sm_oob *oob)
324 {
325 struct mtd_oob_ops ops;
326 struct mtd_info *mtd = ftl->trans->mtd;
327 int ret;
328
329 BUG_ON(ftl->readonly);
330
331 if (zone == 0 && (block == ftl->cis_block || block == 0)) {
332 dbg("attempted to write the CIS!");
333 return -EIO;
334 }
335
336 if (ftl->unstable)
337 return -EIO;
338
339 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB;
340 ops.len = SM_SECTOR_SIZE;
341 ops.datbuf = buffer;
342 ops.ooboffs = 0;
343 ops.ooblen = SM_OOB_SIZE;
344 ops.oobbuf = (void *)oob;
345
346 ret = mtd_write_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops);
347
348 /* Now we assume that hardware will catch write bitflip errors */
349
350 if (ret) {
351 dbg("write to block %d at zone %d, failed with error %d",
352 block, zone, ret);
353
354 sm_recheck_media(ftl);
355 return ret;
356 }
357
358 /* This should never happen, unless there is a bug in the driver */
359 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
360 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
361
362 return 0;
363 }
364
365 /* ------------------------ block IO ------------------------------------- */
366
367 /* Write a block using data and lba, and invalid sector bitmap */
368 static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf,
369 int zone, int block, int lba,
370 unsigned long invalid_bitmap)
371 {
372 struct sm_oob oob;
373 int boffset;
374 int retry = 0;
375
376 /* Initialize the oob with requested values */
377 memset(&oob, 0xFF, SM_OOB_SIZE);
378 sm_write_lba(&oob, lba);
379 restart:
380 if (ftl->unstable)
381 return -EIO;
382
383 for (boffset = 0; boffset < ftl->block_size;
384 boffset += SM_SECTOR_SIZE) {
385
386 oob.data_status = 0xFF;
387
388 if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) {
389
390 sm_printk("sector %d of block at LBA %d of zone %d"
391 " coudn't be read, marking it as invalid",
392 boffset / SM_SECTOR_SIZE, lba, zone);
393
394 oob.data_status = 0;
395 }
396
397 if (ftl->smallpagenand) {
398 __nand_calculate_ecc(buf + boffset,
399 SM_SMALL_PAGE, oob.ecc1);
400
401 __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE,
402 SM_SMALL_PAGE, oob.ecc2);
403 }
404 if (!sm_write_sector(ftl, zone, block, boffset,
405 buf + boffset, &oob))
406 continue;
407
408 if (!retry) {
409
410 /* If write fails. try to erase the block */
411 /* This is safe, because we never write in blocks
412 that contain valuable data.
413 This is intended to repair block that are marked
414 as erased, but that isn't fully erased*/
415
416 if (sm_erase_block(ftl, zone, block, 0))
417 return -EIO;
418
419 retry = 1;
420 goto restart;
421 } else {
422 sm_mark_block_bad(ftl, zone, block);
423 return -EIO;
424 }
425 }
426 return 0;
427 }
428
429
430 /* Mark whole block at offset 'offs' as bad. */
431 static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block)
432 {
433 struct sm_oob oob;
434 int boffset;
435
436 memset(&oob, 0xFF, SM_OOB_SIZE);
437 oob.block_status = 0xF0;
438
439 if (ftl->unstable)
440 return;
441
442 if (sm_recheck_media(ftl))
443 return;
444
445 sm_printk("marking block %d of zone %d as bad", block, zone);
446
447 /* We aren't checking the return value, because we don't care */
448 /* This also fails on fake xD cards, but I guess these won't expose
449 any bad blocks till fail completely */
450 for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE)
451 sm_write_sector(ftl, zone, block, boffset, NULL, &oob);
452 }
453
454 /*
455 * Erase a block within a zone
456 * If erase succeeds, it updates free block fifo, otherwise marks block as bad
457 */
458 static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block,
459 int put_free)
460 {
461 struct ftl_zone *zone = &ftl->zones[zone_num];
462 struct mtd_info *mtd = ftl->trans->mtd;
463 struct erase_info erase;
464
465 erase.mtd = mtd;
466 erase.callback = sm_erase_callback;
467 erase.addr = sm_mkoffset(ftl, zone_num, block, 0);
468 erase.len = ftl->block_size;
469 erase.priv = (u_long)ftl;
470
471 if (ftl->unstable)
472 return -EIO;
473
474 BUG_ON(ftl->readonly);
475
476 if (zone_num == 0 && (block == ftl->cis_block || block == 0)) {
477 sm_printk("attempted to erase the CIS!");
478 return -EIO;
479 }
480
481 if (mtd_erase(mtd, &erase)) {
482 sm_printk("erase of block %d in zone %d failed",
483 block, zone_num);
484 goto error;
485 }
486
487 if (erase.state == MTD_ERASE_PENDING)
488 wait_for_completion(&ftl->erase_completion);
489
490 if (erase.state != MTD_ERASE_DONE) {
491 sm_printk("erase of block %d in zone %d failed after wait",
492 block, zone_num);
493 goto error;
494 }
495
496 if (put_free)
497 kfifo_in(&zone->free_sectors,
498 (const unsigned char *)&block, sizeof(block));
499
500 return 0;
501 error:
502 sm_mark_block_bad(ftl, zone_num, block);
503 return -EIO;
504 }
505
506 static void sm_erase_callback(struct erase_info *self)
507 {
508 struct sm_ftl *ftl = (struct sm_ftl *)self->priv;
509 complete(&ftl->erase_completion);
510 }
511
512 /* Thoroughly test that block is valid. */
513 static int sm_check_block(struct sm_ftl *ftl, int zone, int block)
514 {
515 int boffset;
516 struct sm_oob oob;
517 int lbas[] = { -3, 0, 0, 0 };
518 int i = 0;
519 int test_lba;
520
521
522 /* First just check that block doesn't look fishy */
523 /* Only blocks that are valid or are sliced in two parts, are
524 accepted */
525 for (boffset = 0; boffset < ftl->block_size;
526 boffset += SM_SECTOR_SIZE) {
527
528 /* This shouldn't happen anyway */
529 if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob))
530 return -2;
531
532 test_lba = sm_read_lba(&oob);
533
534 if (lbas[i] != test_lba)
535 lbas[++i] = test_lba;
536
537 /* If we found three different LBAs, something is fishy */
538 if (i == 3)
539 return -EIO;
540 }
541
542 /* If the block is sliced (partially erased usually) erase it */
543 if (i == 2) {
544 sm_erase_block(ftl, zone, block, 1);
545 return 1;
546 }
547
548 return 0;
549 }
550
551 /* ----------------- media scanning --------------------------------- */
552 static const struct chs_entry chs_table[] = {
553 { 1, 125, 4, 4 },
554 { 2, 125, 4, 8 },
555 { 4, 250, 4, 8 },
556 { 8, 250, 4, 16 },
557 { 16, 500, 4, 16 },
558 { 32, 500, 8, 16 },
559 { 64, 500, 8, 32 },
560 { 128, 500, 16, 32 },
561 { 256, 1000, 16, 32 },
562 { 512, 1015, 32, 63 },
563 { 1024, 985, 33, 63 },
564 { 2048, 985, 33, 63 },
565 { 0 },
566 };
567
568
569 static const uint8_t cis_signature[] = {
570 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
571 };
572 /* Find out media parameters.
573 * This ideally has to be based on nand id, but for now device size is enough */
574 int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd)
575 {
576 int i;
577 int size_in_megs = mtd->size / (1024 * 1024);
578
579 ftl->readonly = mtd->type == MTD_ROM;
580
581 /* Manual settings for very old devices */
582 ftl->zone_count = 1;
583 ftl->smallpagenand = 0;
584
585 switch (size_in_megs) {
586 case 1:
587 /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/
588 ftl->zone_size = 256;
589 ftl->max_lba = 250;
590 ftl->block_size = 8 * SM_SECTOR_SIZE;
591 ftl->smallpagenand = 1;
592
593 break;
594 case 2:
595 /* 2 MiB flash SmartMedia (256 byte pages)*/
596 if (mtd->writesize == SM_SMALL_PAGE) {
597 ftl->zone_size = 512;
598 ftl->max_lba = 500;
599 ftl->block_size = 8 * SM_SECTOR_SIZE;
600 ftl->smallpagenand = 1;
601 /* 2 MiB rom SmartMedia */
602 } else {
603
604 if (!ftl->readonly)
605 return -ENODEV;
606
607 ftl->zone_size = 256;
608 ftl->max_lba = 250;
609 ftl->block_size = 16 * SM_SECTOR_SIZE;
610 }
611 break;
612 case 4:
613 /* 4 MiB flash/rom SmartMedia device */
614 ftl->zone_size = 512;
615 ftl->max_lba = 500;
616 ftl->block_size = 16 * SM_SECTOR_SIZE;
617 break;
618 case 8:
619 /* 8 MiB flash/rom SmartMedia device */
620 ftl->zone_size = 1024;
621 ftl->max_lba = 1000;
622 ftl->block_size = 16 * SM_SECTOR_SIZE;
623 }
624
625 /* Minimum xD size is 16MiB. Also, all xD cards have standard zone
626 sizes. SmartMedia cards exist up to 128 MiB and have same layout*/
627 if (size_in_megs >= 16) {
628 ftl->zone_count = size_in_megs / 16;
629 ftl->zone_size = 1024;
630 ftl->max_lba = 1000;
631 ftl->block_size = 32 * SM_SECTOR_SIZE;
632 }
633
634 /* Test for proper write,erase and oob sizes */
635 if (mtd->erasesize > ftl->block_size)
636 return -ENODEV;
637
638 if (mtd->writesize > SM_SECTOR_SIZE)
639 return -ENODEV;
640
641 if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE)
642 return -ENODEV;
643
644 if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE)
645 return -ENODEV;
646
647 /* We use OOB */
648 if (!mtd_has_oob(mtd))
649 return -ENODEV;
650
651 /* Find geometry information */
652 for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) {
653 if (chs_table[i].size == size_in_megs) {
654 ftl->cylinders = chs_table[i].cyl;
655 ftl->heads = chs_table[i].head;
656 ftl->sectors = chs_table[i].sec;
657 return 0;
658 }
659 }
660
661 sm_printk("media has unknown size : %dMiB", size_in_megs);
662 ftl->cylinders = 985;
663 ftl->heads = 33;
664 ftl->sectors = 63;
665 return 0;
666 }
667
668 /* Validate the CIS */
669 static int sm_read_cis(struct sm_ftl *ftl)
670 {
671 struct sm_oob oob;
672
673 if (sm_read_sector(ftl,
674 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob))
675 return -EIO;
676
677 if (!sm_sector_valid(&oob) || !sm_block_valid(&oob))
678 return -EIO;
679
680 if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset,
681 cis_signature, sizeof(cis_signature))) {
682 return 0;
683 }
684
685 return -EIO;
686 }
687
688 /* Scan the media for the CIS */
689 static int sm_find_cis(struct sm_ftl *ftl)
690 {
691 struct sm_oob oob;
692 int block, boffset;
693 int block_found = 0;
694 int cis_found = 0;
695
696 /* Search for first valid block */
697 for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) {
698
699 if (sm_read_sector(ftl, 0, block, 0, NULL, &oob))
700 continue;
701
702 if (!sm_block_valid(&oob))
703 continue;
704 block_found = 1;
705 break;
706 }
707
708 if (!block_found)
709 return -EIO;
710
711 /* Search for first valid sector in this block */
712 for (boffset = 0 ; boffset < ftl->block_size;
713 boffset += SM_SECTOR_SIZE) {
714
715 if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob))
716 continue;
717
718 if (!sm_sector_valid(&oob))
719 continue;
720 break;
721 }
722
723 if (boffset == ftl->block_size)
724 return -EIO;
725
726 ftl->cis_block = block;
727 ftl->cis_boffset = boffset;
728 ftl->cis_page_offset = 0;
729
730 cis_found = !sm_read_cis(ftl);
731
732 if (!cis_found) {
733 ftl->cis_page_offset = SM_SMALL_PAGE;
734 cis_found = !sm_read_cis(ftl);
735 }
736
737 if (cis_found) {
738 dbg("CIS block found at offset %x",
739 block * ftl->block_size +
740 boffset + ftl->cis_page_offset);
741 return 0;
742 }
743 return -EIO;
744 }
745
746 /* Basic test to determine if underlying mtd device if functional */
747 static int sm_recheck_media(struct sm_ftl *ftl)
748 {
749 if (sm_read_cis(ftl)) {
750
751 if (!ftl->unstable) {
752 sm_printk("media unstable, not allowing writes");
753 ftl->unstable = 1;
754 }
755 return -EIO;
756 }
757 return 0;
758 }
759
760 /* Initialize a FTL zone */
761 static int sm_init_zone(struct sm_ftl *ftl, int zone_num)
762 {
763 struct ftl_zone *zone = &ftl->zones[zone_num];
764 struct sm_oob oob;
765 uint16_t block;
766 int lba;
767 int i = 0;
768 int len;
769
770 dbg("initializing zone %d", zone_num);
771
772 /* Allocate memory for FTL table */
773 zone->lba_to_phys_table = kmalloc(ftl->max_lba * 2, GFP_KERNEL);
774
775 if (!zone->lba_to_phys_table)
776 return -ENOMEM;
777 memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2);
778
779
780 /* Allocate memory for free sectors FIFO */
781 if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) {
782 kfree(zone->lba_to_phys_table);
783 return -ENOMEM;
784 }
785
786 /* Now scan the zone */
787 for (block = 0 ; block < ftl->zone_size ; block++) {
788
789 /* Skip blocks till the CIS (including) */
790 if (zone_num == 0 && block <= ftl->cis_block)
791 continue;
792
793 /* Read the oob of first sector */
794 if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob))
795 return -EIO;
796
797 /* Test to see if block is erased. It is enough to test
798 first sector, because erase happens in one shot */
799 if (sm_block_erased(&oob)) {
800 kfifo_in(&zone->free_sectors,
801 (unsigned char *)&block, 2);
802 continue;
803 }
804
805 /* If block is marked as bad, skip it */
806 /* This assumes we can trust first sector*/
807 /* However the way the block valid status is defined, ensures
808 very low probability of failure here */
809 if (!sm_block_valid(&oob)) {
810 dbg("PH %04d <-> <marked bad>", block);
811 continue;
812 }
813
814
815 lba = sm_read_lba(&oob);
816
817 /* Invalid LBA means that block is damaged. */
818 /* We can try to erase it, or mark it as bad, but
819 lets leave that to recovery application */
820 if (lba == -2 || lba >= ftl->max_lba) {
821 dbg("PH %04d <-> LBA %04d(bad)", block, lba);
822 continue;
823 }
824
825
826 /* If there is no collision,
827 just put the sector in the FTL table */
828 if (zone->lba_to_phys_table[lba] < 0) {
829 dbg_verbose("PH %04d <-> LBA %04d", block, lba);
830 zone->lba_to_phys_table[lba] = block;
831 continue;
832 }
833
834 sm_printk("collision"
835 " of LBA %d between blocks %d and %d in zone %d",
836 lba, zone->lba_to_phys_table[lba], block, zone_num);
837
838 /* Test that this block is valid*/
839 if (sm_check_block(ftl, zone_num, block))
840 continue;
841
842 /* Test now the old block */
843 if (sm_check_block(ftl, zone_num,
844 zone->lba_to_phys_table[lba])) {
845 zone->lba_to_phys_table[lba] = block;
846 continue;
847 }
848
849 /* If both blocks are valid and share same LBA, it means that
850 they hold different versions of same data. It not
851 known which is more recent, thus just erase one of them
852 */
853 sm_printk("both blocks are valid, erasing the later");
854 sm_erase_block(ftl, zone_num, block, 1);
855 }
856
857 dbg("zone initialized");
858 zone->initialized = 1;
859
860 /* No free sectors, means that the zone is heavily damaged, write won't
861 work, but it can still can be (partially) read */
862 if (!kfifo_len(&zone->free_sectors)) {
863 sm_printk("no free blocks in zone %d", zone_num);
864 return 0;
865 }
866
867 /* Randomize first block we write to */
868 get_random_bytes(&i, 2);
869 i %= (kfifo_len(&zone->free_sectors) / 2);
870
871 while (i--) {
872 len = kfifo_out(&zone->free_sectors,
873 (unsigned char *)&block, 2);
874 WARN_ON(len != 2);
875 kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
876 }
877 return 0;
878 }
879
880 /* Get and automatically initialize an FTL mapping for one zone */
881 struct ftl_zone *sm_get_zone(struct sm_ftl *ftl, int zone_num)
882 {
883 struct ftl_zone *zone;
884 int error;
885
886 BUG_ON(zone_num >= ftl->zone_count);
887 zone = &ftl->zones[zone_num];
888
889 if (!zone->initialized) {
890 error = sm_init_zone(ftl, zone_num);
891
892 if (error)
893 return ERR_PTR(error);
894 }
895 return zone;
896 }
897
898
899 /* ----------------- cache handling ------------------------------------------*/
900
901 /* Initialize the one block cache */
902 void sm_cache_init(struct sm_ftl *ftl)
903 {
904 ftl->cache_data_invalid_bitmap = 0xFFFFFFFF;
905 ftl->cache_clean = 1;
906 ftl->cache_zone = -1;
907 ftl->cache_block = -1;
908 /*memset(ftl->cache_data, 0xAA, ftl->block_size);*/
909 }
910
911 /* Put sector in one block cache */
912 void sm_cache_put(struct sm_ftl *ftl, char *buffer, int boffset)
913 {
914 memcpy(ftl->cache_data + boffset, buffer, SM_SECTOR_SIZE);
915 clear_bit(boffset / SM_SECTOR_SIZE, &ftl->cache_data_invalid_bitmap);
916 ftl->cache_clean = 0;
917 }
918
919 /* Read a sector from the cache */
920 int sm_cache_get(struct sm_ftl *ftl, char *buffer, int boffset)
921 {
922 if (test_bit(boffset / SM_SECTOR_SIZE,
923 &ftl->cache_data_invalid_bitmap))
924 return -1;
925
926 memcpy(buffer, ftl->cache_data + boffset, SM_SECTOR_SIZE);
927 return 0;
928 }
929
930 /* Write the cache to hardware */
931 int sm_cache_flush(struct sm_ftl *ftl)
932 {
933 struct ftl_zone *zone;
934
935 int sector_num;
936 uint16_t write_sector;
937 int zone_num = ftl->cache_zone;
938 int block_num;
939
940 if (ftl->cache_clean)
941 return 0;
942
943 if (ftl->unstable)
944 return -EIO;
945
946 BUG_ON(zone_num < 0);
947 zone = &ftl->zones[zone_num];
948 block_num = zone->lba_to_phys_table[ftl->cache_block];
949
950
951 /* Try to read all unread areas of the cache block*/
952 for_each_set_bit(sector_num, &ftl->cache_data_invalid_bitmap,
953 ftl->block_size / SM_SECTOR_SIZE) {
954
955 if (!sm_read_sector(ftl,
956 zone_num, block_num, sector_num * SM_SECTOR_SIZE,
957 ftl->cache_data + sector_num * SM_SECTOR_SIZE, NULL))
958 clear_bit(sector_num,
959 &ftl->cache_data_invalid_bitmap);
960 }
961 restart:
962
963 if (ftl->unstable)
964 return -EIO;
965
966 /* If there are no spare blocks, */
967 /* we could still continue by erasing/writing the current block,
968 but for such worn out media it doesn't worth the trouble,
969 and the dangers */
970 if (kfifo_out(&zone->free_sectors,
971 (unsigned char *)&write_sector, 2) != 2) {
972 dbg("no free sectors for write!");
973 return -EIO;
974 }
975
976
977 if (sm_write_block(ftl, ftl->cache_data, zone_num, write_sector,
978 ftl->cache_block, ftl->cache_data_invalid_bitmap))
979 goto restart;
980
981 /* Update the FTL table */
982 zone->lba_to_phys_table[ftl->cache_block] = write_sector;
983
984 /* Write succesfull, so erase and free the old block */
985 if (block_num > 0)
986 sm_erase_block(ftl, zone_num, block_num, 1);
987
988 sm_cache_init(ftl);
989 return 0;
990 }
991
992
993 /* flush timer, runs a second after last write */
994 static void sm_cache_flush_timer(unsigned long data)
995 {
996 struct sm_ftl *ftl = (struct sm_ftl *)data;
997 queue_work(cache_flush_workqueue, &ftl->flush_work);
998 }
999
1000 /* cache flush work, kicked by timer */
1001 static void sm_cache_flush_work(struct work_struct *work)
1002 {
1003 struct sm_ftl *ftl = container_of(work, struct sm_ftl, flush_work);
1004 mutex_lock(&ftl->mutex);
1005 sm_cache_flush(ftl);
1006 mutex_unlock(&ftl->mutex);
1007 return;
1008 }
1009
1010 /* ---------------- outside interface -------------------------------------- */
1011
1012 /* outside interface: read a sector */
1013 static int sm_read(struct mtd_blktrans_dev *dev,
1014 unsigned long sect_no, char *buf)
1015 {
1016 struct sm_ftl *ftl = dev->priv;
1017 struct ftl_zone *zone;
1018 int error = 0, in_cache = 0;
1019 int zone_num, block, boffset;
1020
1021 sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset);
1022 mutex_lock(&ftl->mutex);
1023
1024
1025 zone = sm_get_zone(ftl, zone_num);
1026 if (IS_ERR(zone)) {
1027 error = PTR_ERR(zone);
1028 goto unlock;
1029 }
1030
1031 /* Have to look at cache first */
1032 if (ftl->cache_zone == zone_num && ftl->cache_block == block) {
1033 in_cache = 1;
1034 if (!sm_cache_get(ftl, buf, boffset))
1035 goto unlock;
1036 }
1037
1038 /* Translate the block and return if doesn't exist in the table */
1039 block = zone->lba_to_phys_table[block];
1040
1041 if (block == -1) {
1042 memset(buf, 0xFF, SM_SECTOR_SIZE);
1043 goto unlock;
1044 }
1045
1046 if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) {
1047 error = -EIO;
1048 goto unlock;
1049 }
1050
1051 if (in_cache)
1052 sm_cache_put(ftl, buf, boffset);
1053 unlock:
1054 mutex_unlock(&ftl->mutex);
1055 return error;
1056 }
1057
1058 /* outside interface: write a sector */
1059 static int sm_write(struct mtd_blktrans_dev *dev,
1060 unsigned long sec_no, char *buf)
1061 {
1062 struct sm_ftl *ftl = dev->priv;
1063 struct ftl_zone *zone;
1064 int error, zone_num, block, boffset;
1065
1066 BUG_ON(ftl->readonly);
1067 sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset);
1068
1069 /* No need in flush thread running now */
1070 del_timer(&ftl->timer);
1071 mutex_lock(&ftl->mutex);
1072
1073 zone = sm_get_zone(ftl, zone_num);
1074 if (IS_ERR(zone)) {
1075 error = PTR_ERR(zone);
1076 goto unlock;
1077 }
1078
1079 /* If entry is not in cache, flush it */
1080 if (ftl->cache_block != block || ftl->cache_zone != zone_num) {
1081
1082 error = sm_cache_flush(ftl);
1083 if (error)
1084 goto unlock;
1085
1086 ftl->cache_block = block;
1087 ftl->cache_zone = zone_num;
1088 }
1089
1090 sm_cache_put(ftl, buf, boffset);
1091 unlock:
1092 mod_timer(&ftl->timer, jiffies + msecs_to_jiffies(cache_timeout));
1093 mutex_unlock(&ftl->mutex);
1094 return error;
1095 }
1096
1097 /* outside interface: flush everything */
1098 static int sm_flush(struct mtd_blktrans_dev *dev)
1099 {
1100 struct sm_ftl *ftl = dev->priv;
1101 int retval;
1102
1103 mutex_lock(&ftl->mutex);
1104 retval = sm_cache_flush(ftl);
1105 mutex_unlock(&ftl->mutex);
1106 return retval;
1107 }
1108
1109 /* outside interface: device is released */
1110 static int sm_release(struct mtd_blktrans_dev *dev)
1111 {
1112 struct sm_ftl *ftl = dev->priv;
1113
1114 mutex_lock(&ftl->mutex);
1115 del_timer_sync(&ftl->timer);
1116 cancel_work_sync(&ftl->flush_work);
1117 sm_cache_flush(ftl);
1118 mutex_unlock(&ftl->mutex);
1119 return 0;
1120 }
1121
1122 /* outside interface: get geometry */
1123 static int sm_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
1124 {
1125 struct sm_ftl *ftl = dev->priv;
1126 geo->heads = ftl->heads;
1127 geo->sectors = ftl->sectors;
1128 geo->cylinders = ftl->cylinders;
1129 return 0;
1130 }
1131
1132 /* external interface: main initialization function */
1133 static void sm_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
1134 {
1135 struct mtd_blktrans_dev *trans;
1136 struct sm_ftl *ftl;
1137
1138 /* Allocate & initialize our private structure */
1139 ftl = kzalloc(sizeof(struct sm_ftl), GFP_KERNEL);
1140 if (!ftl)
1141 goto error1;
1142
1143
1144 mutex_init(&ftl->mutex);
1145 setup_timer(&ftl->timer, sm_cache_flush_timer, (unsigned long)ftl);
1146 INIT_WORK(&ftl->flush_work, sm_cache_flush_work);
1147 init_completion(&ftl->erase_completion);
1148
1149 /* Read media information */
1150 if (sm_get_media_info(ftl, mtd)) {
1151 dbg("found unsupported mtd device, aborting");
1152 goto error2;
1153 }
1154
1155
1156 /* Allocate temporary CIS buffer for read retry support */
1157 ftl->cis_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
1158 if (!ftl->cis_buffer)
1159 goto error2;
1160
1161 /* Allocate zone array, it will be initialized on demand */
1162 ftl->zones = kzalloc(sizeof(struct ftl_zone) * ftl->zone_count,
1163 GFP_KERNEL);
1164 if (!ftl->zones)
1165 goto error3;
1166
1167 /* Allocate the cache*/
1168 ftl->cache_data = kzalloc(ftl->block_size, GFP_KERNEL);
1169
1170 if (!ftl->cache_data)
1171 goto error4;
1172
1173 sm_cache_init(ftl);
1174
1175
1176 /* Allocate upper layer structure and initialize it */
1177 trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL);
1178 if (!trans)
1179 goto error5;
1180
1181 ftl->trans = trans;
1182 trans->priv = ftl;
1183
1184 trans->tr = tr;
1185 trans->mtd = mtd;
1186 trans->devnum = -1;
1187 trans->size = (ftl->block_size * ftl->max_lba * ftl->zone_count) >> 9;
1188 trans->readonly = ftl->readonly;
1189
1190 if (sm_find_cis(ftl)) {
1191 dbg("CIS not found on mtd device, aborting");
1192 goto error6;
1193 }
1194
1195 ftl->disk_attributes = sm_create_sysfs_attributes(ftl);
1196 if (!ftl->disk_attributes)
1197 goto error6;
1198 trans->disk_attributes = ftl->disk_attributes;
1199
1200 sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d",
1201 (int)(mtd->size / (1024 * 1024)), mtd->index);
1202
1203 dbg("FTL layout:");
1204 dbg("%d zone(s), each consists of %d blocks (+%d spares)",
1205 ftl->zone_count, ftl->max_lba,
1206 ftl->zone_size - ftl->max_lba);
1207 dbg("each block consists of %d bytes",
1208 ftl->block_size);
1209
1210
1211 /* Register device*/
1212 if (add_mtd_blktrans_dev(trans)) {
1213 dbg("error in mtdblktrans layer");
1214 goto error6;
1215 }
1216 return;
1217 error6:
1218 kfree(trans);
1219 error5:
1220 kfree(ftl->cache_data);
1221 error4:
1222 kfree(ftl->zones);
1223 error3:
1224 kfree(ftl->cis_buffer);
1225 error2:
1226 kfree(ftl);
1227 error1:
1228 return;
1229 }
1230
1231 /* main interface: device {surprise,} removal */
1232 static void sm_remove_dev(struct mtd_blktrans_dev *dev)
1233 {
1234 struct sm_ftl *ftl = dev->priv;
1235 int i;
1236
1237 del_mtd_blktrans_dev(dev);
1238 ftl->trans = NULL;
1239
1240 for (i = 0 ; i < ftl->zone_count; i++) {
1241
1242 if (!ftl->zones[i].initialized)
1243 continue;
1244
1245 kfree(ftl->zones[i].lba_to_phys_table);
1246 kfifo_free(&ftl->zones[i].free_sectors);
1247 }
1248
1249 sm_delete_sysfs_attributes(ftl);
1250 kfree(ftl->cis_buffer);
1251 kfree(ftl->zones);
1252 kfree(ftl->cache_data);
1253 kfree(ftl);
1254 }
1255
1256 static struct mtd_blktrans_ops sm_ftl_ops = {
1257 .name = "smblk",
1258 .major = 0,
1259 .part_bits = SM_FTL_PARTN_BITS,
1260 .blksize = SM_SECTOR_SIZE,
1261 .getgeo = sm_getgeo,
1262
1263 .add_mtd = sm_add_mtd,
1264 .remove_dev = sm_remove_dev,
1265
1266 .readsect = sm_read,
1267 .writesect = sm_write,
1268
1269 .flush = sm_flush,
1270 .release = sm_release,
1271
1272 .owner = THIS_MODULE,
1273 };
1274
1275 static __init int sm_module_init(void)
1276 {
1277 int error = 0;
1278 cache_flush_workqueue = create_freezable_workqueue("smflush");
1279
1280 if (IS_ERR(cache_flush_workqueue))
1281 return PTR_ERR(cache_flush_workqueue);
1282
1283 error = register_mtd_blktrans(&sm_ftl_ops);
1284 if (error)
1285 destroy_workqueue(cache_flush_workqueue);
1286 return error;
1287
1288 }
1289
1290 static void __exit sm_module_exit(void)
1291 {
1292 destroy_workqueue(cache_flush_workqueue);
1293 deregister_mtd_blktrans(&sm_ftl_ops);
1294 }
1295
1296 module_init(sm_module_init);
1297 module_exit(sm_module_exit);
1298
1299 MODULE_LICENSE("GPL");
1300 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1301 MODULE_DESCRIPTION("Smartmedia/xD mtd translation layer");
Linus' kernel tree