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Merge branch 'x86-smep-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6/next.git] / drivers / mtd / sm_ftl.c
blobed3d6cd2c6dca216e097bfd5491544283be5ac11
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 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 - endianess 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 asscociated 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 vertification */
256 if (!oob)
257 oob = &tmp_oob;
258
259 ops.mode = ftl->smallpagenand ? MTD_OOB_RAW : MTD_OOB_PLACE;
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 /* Unfortunelly, 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 && ret != -EUCLEAN && ret != -EBADMSG) {
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 (ret == -EBADMSG ||
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_OOB_RAW : MTD_OOB_PLACE;
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 /* If you are paranoid, use CONFIG_MTD_NAND_VERIFY_WRITE */
350
351 if (ret) {
352 dbg("write to block %d at zone %d, failed with error %d",
353 block, zone, ret);
354
355 sm_recheck_media(ftl);
356 return ret;
357 }
358
359 /* This should never happen, unless there is a bug in the driver */
360 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
361 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
362
363 return 0;
364 }
365
366 /* ------------------------ block IO ------------------------------------- */
367
368 /* Write a block using data and lba, and invalid sector bitmap */
369 static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf,
370 int zone, int block, int lba,
371 unsigned long invalid_bitmap)
372 {
373 struct sm_oob oob;
374 int boffset;
375 int retry = 0;
376
377 /* Initialize the oob with requested values */
378 memset(&oob, 0xFF, SM_OOB_SIZE);
379 sm_write_lba(&oob, lba);
380 restart:
381 if (ftl->unstable)
382 return -EIO;
383
384 for (boffset = 0; boffset < ftl->block_size;
385 boffset += SM_SECTOR_SIZE) {
386
387 oob.data_status = 0xFF;
388
389 if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) {
390
391 sm_printk("sector %d of block at LBA %d of zone %d"
392 " coudn't be read, marking it as invalid",
393 boffset / SM_SECTOR_SIZE, lba, zone);
394
395 oob.data_status = 0;
396 }
397
398 if (ftl->smallpagenand) {
399 __nand_calculate_ecc(buf + boffset,
400 SM_SMALL_PAGE, oob.ecc1);
401
402 __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE,
403 SM_SMALL_PAGE, oob.ecc2);
404 }
405 if (!sm_write_sector(ftl, zone, block, boffset,
406 buf + boffset, &oob))
407 continue;
408
409 if (!retry) {
410
411 /* If write fails. try to erase the block */
412 /* This is safe, because we never write in blocks
413 that contain valuable data.
414 This is intended to repair block that are marked
415 as erased, but that isn't fully erased*/
416
417 if (sm_erase_block(ftl, zone, block, 0))
418 return -EIO;
419
420 retry = 1;
421 goto restart;
422 } else {
423 sm_mark_block_bad(ftl, zone, block);
424 return -EIO;
425 }
426 }
427 return 0;
428 }
429
430
431 /* Mark whole block at offset 'offs' as bad. */
432 static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block)
433 {
434 struct sm_oob oob;
435 int boffset;
436
437 memset(&oob, 0xFF, SM_OOB_SIZE);
438 oob.block_status = 0xF0;
439
440 if (ftl->unstable)
441 return;
442
443 if (sm_recheck_media(ftl))
444 return;
445
446 sm_printk("marking block %d of zone %d as bad", block, zone);
447
448 /* We aren't checking the return value, because we don't care */
449 /* This also fails on fake xD cards, but I guess these won't expose
450 any bad blocks till fail completly */
451 for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE)
452 sm_write_sector(ftl, zone, block, boffset, NULL, &oob);
453 }
454
455 /*
456 * Erase a block within a zone
457 * If erase succedes, it updates free block fifo, otherwise marks block as bad
458 */
459 static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block,
460 int put_free)
461 {
462 struct ftl_zone *zone = &ftl->zones[zone_num];
463 struct mtd_info *mtd = ftl->trans->mtd;
464 struct erase_info erase;
465
466 erase.mtd = mtd;
467 erase.callback = sm_erase_callback;
468 erase.addr = sm_mkoffset(ftl, zone_num, block, 0);
469 erase.len = ftl->block_size;
470 erase.priv = (u_long)ftl;
471
472 if (ftl->unstable)
473 return -EIO;
474
475 BUG_ON(ftl->readonly);
476
477 if (zone_num == 0 && (block == ftl->cis_block || block == 0)) {
478 sm_printk("attempted to erase the CIS!");
479 return -EIO;
480 }
481
482 if (mtd->erase(mtd, &erase)) {
483 sm_printk("erase of block %d in zone %d failed",
484 block, zone_num);
485 goto error;
486 }
487
488 if (erase.state == MTD_ERASE_PENDING)
489 wait_for_completion(&ftl->erase_completion);
490
491 if (erase.state != MTD_ERASE_DONE) {
492 sm_printk("erase of block %d in zone %d failed after wait",
493 block, zone_num);
494 goto error;
495 }
496
497 if (put_free)
498 kfifo_in(&zone->free_sectors,
499 (const unsigned char *)&block, sizeof(block));
500
501 return 0;
502 error:
503 sm_mark_block_bad(ftl, zone_num, block);
504 return -EIO;
505 }
506
507 static void sm_erase_callback(struct erase_info *self)
508 {
509 struct sm_ftl *ftl = (struct sm_ftl *)self->priv;
510 complete(&ftl->erase_completion);
511 }
512
513 /* Throughtly test that block is valid. */
514 static int sm_check_block(struct sm_ftl *ftl, int zone, int block)
515 {
516 int boffset;
517 struct sm_oob oob;
518 int lbas[] = { -3, 0, 0, 0 };
519 int i = 0;
520 int test_lba;
521
522
523 /* First just check that block doesn't look fishy */
524 /* Only blocks that are valid or are sliced in two parts, are
525 accepted */
526 for (boffset = 0; boffset < ftl->block_size;
527 boffset += SM_SECTOR_SIZE) {
528
529 /* This shoudn't happen anyway */
530 if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob))
531 return -2;
532
533 test_lba = sm_read_lba(&oob);
534
535 if (lbas[i] != test_lba)
536 lbas[++i] = test_lba;
537
538 /* If we found three different LBAs, something is fishy */
539 if (i == 3)
540 return -EIO;
541 }
542
543 /* If the block is sliced (partially erased usually) erase it */
544 if (i == 2) {
545 sm_erase_block(ftl, zone, block, 1);
546 return 1;
547 }
548
549 return 0;
550 }
551
552 /* ----------------- media scanning --------------------------------- */
553 static const struct chs_entry chs_table[] = {
554 { 1, 125, 4, 4 },
555 { 2, 125, 4, 8 },
556 { 4, 250, 4, 8 },
557 { 8, 250, 4, 16 },
558 { 16, 500, 4, 16 },
559 { 32, 500, 8, 16 },
560 { 64, 500, 8, 32 },
561 { 128, 500, 16, 32 },
562 { 256, 1000, 16, 32 },
563 { 512, 1015, 32, 63 },
564 { 1024, 985, 33, 63 },
565 { 2048, 985, 33, 63 },
566 { 0 },
567 };
568
569
570 static const uint8_t cis_signature[] = {
571 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
572 };
573 /* Find out media parameters.
574 * This ideally has to be based on nand id, but for now device size is enough */
575 int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd)
576 {
577 int i;
578 int size_in_megs = mtd->size / (1024 * 1024);
579
580 ftl->readonly = mtd->type == MTD_ROM;
581
582 /* Manual settings for very old devices */
583 ftl->zone_count = 1;
584 ftl->smallpagenand = 0;
585
586 switch (size_in_megs) {
587 case 1:
588 /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/
589 ftl->zone_size = 256;
590 ftl->max_lba = 250;
591 ftl->block_size = 8 * SM_SECTOR_SIZE;
592 ftl->smallpagenand = 1;
593
594 break;
595 case 2:
596 /* 2 MiB flash SmartMedia (256 byte pages)*/
597 if (mtd->writesize == SM_SMALL_PAGE) {
598 ftl->zone_size = 512;
599 ftl->max_lba = 500;
600 ftl->block_size = 8 * SM_SECTOR_SIZE;
601 ftl->smallpagenand = 1;
602 /* 2 MiB rom SmartMedia */
603 } else {
604
605 if (!ftl->readonly)
606 return -ENODEV;
607
608 ftl->zone_size = 256;
609 ftl->max_lba = 250;
610 ftl->block_size = 16 * SM_SECTOR_SIZE;
611 }
612 break;
613 case 4:
614 /* 4 MiB flash/rom SmartMedia device */
615 ftl->zone_size = 512;
616 ftl->max_lba = 500;
617 ftl->block_size = 16 * SM_SECTOR_SIZE;
618 break;
619 case 8:
620 /* 8 MiB flash/rom SmartMedia device */
621 ftl->zone_size = 1024;
622 ftl->max_lba = 1000;
623 ftl->block_size = 16 * SM_SECTOR_SIZE;
624 }
625
626 /* Minimum xD size is 16MiB. Also, all xD cards have standard zone
627 sizes. SmartMedia cards exist up to 128 MiB and have same layout*/
628 if (size_in_megs >= 16) {
629 ftl->zone_count = size_in_megs / 16;
630 ftl->zone_size = 1024;
631 ftl->max_lba = 1000;
632 ftl->block_size = 32 * SM_SECTOR_SIZE;
633 }
634
635 /* Test for proper write,erase and oob sizes */
636 if (mtd->erasesize > ftl->block_size)
637 return -ENODEV;
638
639 if (mtd->writesize > SM_SECTOR_SIZE)
640 return -ENODEV;
641
642 if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE)
643 return -ENODEV;
644
645 if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE)
646 return -ENODEV;
647
648 /* We use these functions for IO */
649 if (!mtd->read_oob || !mtd->write_oob)
650 return -ENODEV;
651
652 /* Find geometry information */
653 for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) {
654 if (chs_table[i].size == size_in_megs) {
655 ftl->cylinders = chs_table[i].cyl;
656 ftl->heads = chs_table[i].head;
657 ftl->sectors = chs_table[i].sec;
658 return 0;
659 }
660 }
661
662 sm_printk("media has unknown size : %dMiB", size_in_megs);
663 ftl->cylinders = 985;
664 ftl->heads = 33;
665 ftl->sectors = 63;
666 return 0;
667 }
668
669 /* Validate the CIS */
670 static int sm_read_cis(struct sm_ftl *ftl)
671 {
672 struct sm_oob oob;
673
674 if (sm_read_sector(ftl,
675 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob))
676 return -EIO;
677
678 if (!sm_sector_valid(&oob) || !sm_block_valid(&oob))
679 return -EIO;
680
681 if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset,
682 cis_signature, sizeof(cis_signature))) {
683 return 0;
684 }
685
686 return -EIO;
687 }
688
689 /* Scan the media for the CIS */
690 static int sm_find_cis(struct sm_ftl *ftl)
691 {
692 struct sm_oob oob;
693 int block, boffset;
694 int block_found = 0;
695 int cis_found = 0;
696
697 /* Search for first valid block */
698 for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) {
699
700 if (sm_read_sector(ftl, 0, block, 0, NULL, &oob))
701 continue;
702
703 if (!sm_block_valid(&oob))
704 continue;
705 block_found = 1;
706 break;
707 }
708
709 if (!block_found)
710 return -EIO;
711
712 /* Search for first valid sector in this block */
713 for (boffset = 0 ; boffset < ftl->block_size;
714 boffset += SM_SECTOR_SIZE) {
715
716 if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob))
717 continue;
718
719 if (!sm_sector_valid(&oob))
720 continue;
721 break;
722 }
723
724 if (boffset == ftl->block_size)
725 return -EIO;
726
727 ftl->cis_block = block;
728 ftl->cis_boffset = boffset;
729 ftl->cis_page_offset = 0;
730
731 cis_found = !sm_read_cis(ftl);
732
733 if (!cis_found) {
734 ftl->cis_page_offset = SM_SMALL_PAGE;
735 cis_found = !sm_read_cis(ftl);
736 }
737
738 if (cis_found) {
739 dbg("CIS block found at offset %x",
740 block * ftl->block_size +
741 boffset + ftl->cis_page_offset);
742 return 0;
743 }
744 return -EIO;
745 }
746
747 /* Basic test to determine if underlying mtd device if functional */
748 static int sm_recheck_media(struct sm_ftl *ftl)
749 {
750 if (sm_read_cis(ftl)) {
751
752 if (!ftl->unstable) {
753 sm_printk("media unstable, not allowing writes");
754 ftl->unstable = 1;
755 }
756 return -EIO;
757 }
758 return 0;
759 }
760
761 /* Initialize a FTL zone */
762 static int sm_init_zone(struct sm_ftl *ftl, int zone_num)
763 {
764 struct ftl_zone *zone = &ftl->zones[zone_num];
765 struct sm_oob oob;
766 uint16_t block;
767 int lba;
768 int i = 0;
769 int len;
770
771 dbg("initializing zone %d", zone_num);
772
773 /* Allocate memory for FTL table */
774 zone->lba_to_phys_table = kmalloc(ftl->max_lba * 2, GFP_KERNEL);
775
776 if (!zone->lba_to_phys_table)
777 return -ENOMEM;
778 memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2);
779
780
781 /* Allocate memory for free sectors FIFO */
782 if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) {
783 kfree(zone->lba_to_phys_table);
784 return -ENOMEM;
785 }
786
787 /* Now scan the zone */
788 for (block = 0 ; block < ftl->zone_size ; block++) {
789
790 /* Skip blocks till the CIS (including) */
791 if (zone_num == 0 && block <= ftl->cis_block)
792 continue;
793
794 /* Read the oob of first sector */
795 if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob))
796 return -EIO;
797
798 /* Test to see if block is erased. It is enough to test
799 first sector, because erase happens in one shot */
800 if (sm_block_erased(&oob)) {
801 kfifo_in(&zone->free_sectors,
802 (unsigned char *)&block, 2);
803 continue;
804 }
805
806 /* If block is marked as bad, skip it */
807 /* This assumes we can trust first sector*/
808 /* However the way the block valid status is defined, ensures
809 very low probability of failure here */
810 if (!sm_block_valid(&oob)) {
811 dbg("PH %04d <-> <marked bad>", block);
812 continue;
813 }
814
815
816 lba = sm_read_lba(&oob);
817
818 /* Invalid LBA means that block is damaged. */
819 /* We can try to erase it, or mark it as bad, but
820 lets leave that to recovery application */
821 if (lba == -2 || lba >= ftl->max_lba) {
822 dbg("PH %04d <-> LBA %04d(bad)", block, lba);
823 continue;
824 }
825
826
827 /* If there is no collision,
828 just put the sector in the FTL table */
829 if (zone->lba_to_phys_table[lba] < 0) {
830 dbg_verbose("PH %04d <-> LBA %04d", block, lba);
831 zone->lba_to_phys_table[lba] = block;
832 continue;
833 }
834
835 sm_printk("collision"
836 " of LBA %d between blocks %d and %d in zone %d",
837 lba, zone->lba_to_phys_table[lba], block, zone_num);
838
839 /* Test that this block is valid*/
840 if (sm_check_block(ftl, zone_num, block))
841 continue;
842
843 /* Test now the old block */
844 if (sm_check_block(ftl, zone_num,
845 zone->lba_to_phys_table[lba])) {
846 zone->lba_to_phys_table[lba] = block;
847 continue;
848 }
849
850 /* If both blocks are valid and share same LBA, it means that
851 they hold different versions of same data. It not
852 known which is more recent, thus just erase one of them
853 */
854 sm_printk("both blocks are valid, erasing the later");
855 sm_erase_block(ftl, zone_num, block, 1);
856 }
857
858 dbg("zone initialized");
859 zone->initialized = 1;
860
861 /* No free sectors, means that the zone is heavily damaged, write won't
862 work, but it can still can be (partially) read */
863 if (!kfifo_len(&zone->free_sectors)) {
864 sm_printk("no free blocks in zone %d", zone_num);
865 return 0;
866 }
867
868 /* Randomize first block we write to */
869 get_random_bytes(&i, 2);
870 i %= (kfifo_len(&zone->free_sectors) / 2);
871
872 while (i--) {
873 len = kfifo_out(&zone->free_sectors,
874 (unsigned char *)&block, 2);
875 WARN_ON(len != 2);
876 kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
877 }
878 return 0;
879 }
880
881 /* Get and automatically initialize an FTL mapping for one zone */
882 struct ftl_zone *sm_get_zone(struct sm_ftl *ftl, int zone_num)
883 {
884 struct ftl_zone *zone;
885 int error;
886
887 BUG_ON(zone_num >= ftl->zone_count);
888 zone = &ftl->zones[zone_num];
889
890 if (!zone->initialized) {
891 error = sm_init_zone(ftl, zone_num);
892
893 if (error)
894 return ERR_PTR(error);
895 }
896 return zone;
897 }
898
899
900 /* ----------------- cache handling ------------------------------------------*/
901
902 /* Initialize the one block cache */
903 void sm_cache_init(struct sm_ftl *ftl)
904 {
905 ftl->cache_data_invalid_bitmap = 0xFFFFFFFF;
906 ftl->cache_clean = 1;
907 ftl->cache_zone = -1;
908 ftl->cache_block = -1;
909 /*memset(ftl->cache_data, 0xAA, ftl->block_size);*/
910 }
911
912 /* Put sector in one block cache */
913 void sm_cache_put(struct sm_ftl *ftl, char *buffer, int boffset)
914 {
915 memcpy(ftl->cache_data + boffset, buffer, SM_SECTOR_SIZE);
916 clear_bit(boffset / SM_SECTOR_SIZE, &ftl->cache_data_invalid_bitmap);
917 ftl->cache_clean = 0;
918 }
919
920 /* Read a sector from the cache */
921 int sm_cache_get(struct sm_ftl *ftl, char *buffer, int boffset)
922 {
923 if (test_bit(boffset / SM_SECTOR_SIZE,
924 &ftl->cache_data_invalid_bitmap))
925 return -1;
926
927 memcpy(buffer, ftl->cache_data + boffset, SM_SECTOR_SIZE);
928 return 0;
929 }
930
931 /* Write the cache to hardware */
932 int sm_cache_flush(struct sm_ftl *ftl)
933 {
934 struct ftl_zone *zone;
935
936 int sector_num;
937 uint16_t write_sector;
938 int zone_num = ftl->cache_zone;
939 int block_num;
940
941 if (ftl->cache_clean)
942 return 0;
943
944 if (ftl->unstable)
945 return -EIO;
946
947 BUG_ON(zone_num < 0);
948 zone = &ftl->zones[zone_num];
949 block_num = zone->lba_to_phys_table[ftl->cache_block];
950
951
952 /* Try to read all unread areas of the cache block*/
953 for_each_set_bit(sector_num, &ftl->cache_data_invalid_bitmap,
954 ftl->block_size / SM_SECTOR_SIZE) {
955
956 if (!sm_read_sector(ftl,
957 zone_num, block_num, sector_num * SM_SECTOR_SIZE,
958 ftl->cache_data + sector_num * SM_SECTOR_SIZE, NULL))
959 clear_bit(sector_num,
960 &ftl->cache_data_invalid_bitmap);
961 }
962 restart:
963
964 if (ftl->unstable)
965 return -EIO;
966
967 /* If there are no spare blocks, */
968 /* we could still continue by erasing/writing the current block,
969 but for such worn out media it doesn't worth the trouble,
970 and the dangers */
971 if (kfifo_out(&zone->free_sectors,
972 (unsigned char *)&write_sector, 2) != 2) {
973 dbg("no free sectors for write!");
974 return -EIO;
975 }
976
977
978 if (sm_write_block(ftl, ftl->cache_data, zone_num, write_sector,
979 ftl->cache_block, ftl->cache_data_invalid_bitmap))
980 goto restart;
981
982 /* Update the FTL table */
983 zone->lba_to_phys_table[ftl->cache_block] = write_sector;
984
985 /* Write succesfull, so erase and free the old block */
986 if (block_num > 0)
987 sm_erase_block(ftl, zone_num, block_num, 1);
988
989 sm_cache_init(ftl);
990 return 0;
991 }
992
993
994 /* flush timer, runs a second after last write */
995 static void sm_cache_flush_timer(unsigned long data)
996 {
997 struct sm_ftl *ftl = (struct sm_ftl *)data;
998 queue_work(cache_flush_workqueue, &ftl->flush_work);
999 }
1000
1001 /* cache flush work, kicked by timer */
1002 static void sm_cache_flush_work(struct work_struct *work)
1003 {
1004 struct sm_ftl *ftl = container_of(work, struct sm_ftl, flush_work);
1005 mutex_lock(&ftl->mutex);
1006 sm_cache_flush(ftl);
1007 mutex_unlock(&ftl->mutex);
1008 return;
1009 }
1010
1011 /* ---------------- outside interface -------------------------------------- */
1012
1013 /* outside interface: read a sector */
1014 static int sm_read(struct mtd_blktrans_dev *dev,
1015 unsigned long sect_no, char *buf)
1016 {
1017 struct sm_ftl *ftl = dev->priv;
1018 struct ftl_zone *zone;
1019 int error = 0, in_cache = 0;
1020 int zone_num, block, boffset;
1021
1022 sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset);
1023 mutex_lock(&ftl->mutex);
1024
1025
1026 zone = sm_get_zone(ftl, zone_num);
1027 if (IS_ERR(zone)) {
1028 error = PTR_ERR(zone);
1029 goto unlock;
1030 }
1031
1032 /* Have to look at cache first */
1033 if (ftl->cache_zone == zone_num && ftl->cache_block == block) {
1034 in_cache = 1;
1035 if (!sm_cache_get(ftl, buf, boffset))
1036 goto unlock;
1037 }
1038
1039 /* Translate the block and return if doesn't exist in the table */
1040 block = zone->lba_to_phys_table[block];
1041
1042 if (block == -1) {
1043 memset(buf, 0xFF, SM_SECTOR_SIZE);
1044 goto unlock;
1045 }
1046
1047 if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) {
1048 error = -EIO;
1049 goto unlock;
1050 }
1051
1052 if (in_cache)
1053 sm_cache_put(ftl, buf, boffset);
1054 unlock:
1055 mutex_unlock(&ftl->mutex);
1056 return error;
1057 }
1058
1059 /* outside interface: write a sector */
1060 static int sm_write(struct mtd_blktrans_dev *dev,
1061 unsigned long sec_no, char *buf)
1062 {
1063 struct sm_ftl *ftl = dev->priv;
1064 struct ftl_zone *zone;
1065 int error, zone_num, block, boffset;
1066
1067 BUG_ON(ftl->readonly);
1068 sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset);
1069
1070 /* No need in flush thread running now */
1071 del_timer(&ftl->timer);
1072 mutex_lock(&ftl->mutex);
1073
1074 zone = sm_get_zone(ftl, zone_num);
1075 if (IS_ERR(zone)) {
1076 error = PTR_ERR(zone);
1077 goto unlock;
1078 }
1079
1080 /* If entry is not in cache, flush it */
1081 if (ftl->cache_block != block || ftl->cache_zone != zone_num) {
1082
1083 error = sm_cache_flush(ftl);
1084 if (error)
1085 goto unlock;
1086
1087 ftl->cache_block = block;
1088 ftl->cache_zone = zone_num;
1089 }
1090
1091 sm_cache_put(ftl, buf, boffset);
1092 unlock:
1093 mod_timer(&ftl->timer, jiffies + msecs_to_jiffies(cache_timeout));
1094 mutex_unlock(&ftl->mutex);
1095 return error;
1096 }
1097
1098 /* outside interface: flush everything */
1099 static int sm_flush(struct mtd_blktrans_dev *dev)
1100 {
1101 struct sm_ftl *ftl = dev->priv;
1102 int retval;
1103
1104 mutex_lock(&ftl->mutex);
1105 retval = sm_cache_flush(ftl);
1106 mutex_unlock(&ftl->mutex);
1107 return retval;
1108 }
1109
1110 /* outside interface: device is released */
1111 static int sm_release(struct mtd_blktrans_dev *dev)
1112 {
1113 struct sm_ftl *ftl = dev->priv;
1114
1115 mutex_lock(&ftl->mutex);
1116 del_timer_sync(&ftl->timer);
1117 cancel_work_sync(&ftl->flush_work);
1118 sm_cache_flush(ftl);
1119 mutex_unlock(&ftl->mutex);
1120 return 0;
1121 }
1122
1123 /* outside interface: get geometry */
1124 static int sm_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
1125 {
1126 struct sm_ftl *ftl = dev->priv;
1127 geo->heads = ftl->heads;
1128 geo->sectors = ftl->sectors;
1129 geo->cylinders = ftl->cylinders;
1130 return 0;
1131 }
1132
1133 /* external interface: main initialization function */
1134 static void sm_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
1135 {
1136 struct mtd_blktrans_dev *trans;
1137 struct sm_ftl *ftl;
1138
1139 /* Allocate & initialize our private structure */
1140 ftl = kzalloc(sizeof(struct sm_ftl), GFP_KERNEL);
1141 if (!ftl)
1142 goto error1;
1143
1144
1145 mutex_init(&ftl->mutex);
1146 setup_timer(&ftl->timer, sm_cache_flush_timer, (unsigned long)ftl);
1147 INIT_WORK(&ftl->flush_work, sm_cache_flush_work);
1148 init_completion(&ftl->erase_completion);
1149
1150 /* Read media information */
1151 if (sm_get_media_info(ftl, mtd)) {
1152 dbg("found unsupported mtd device, aborting");
1153 goto error2;
1154 }
1155
1156
1157 /* Allocate temporary CIS buffer for read retry support */
1158 ftl->cis_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
1159 if (!ftl->cis_buffer)
1160 goto error2;
1161
1162 /* Allocate zone array, it will be initialized on demand */
1163 ftl->zones = kzalloc(sizeof(struct ftl_zone) * ftl->zone_count,
1164 GFP_KERNEL);
1165 if (!ftl->zones)
1166 goto error3;
1167
1168 /* Allocate the cache*/
1169 ftl->cache_data = kzalloc(ftl->block_size, GFP_KERNEL);
1170
1171 if (!ftl->cache_data)
1172 goto error4;
1173
1174 sm_cache_init(ftl);
1175
1176
1177 /* Allocate upper layer structure and initialize it */
1178 trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL);
1179 if (!trans)
1180 goto error5;
1181
1182 ftl->trans = trans;
1183 trans->priv = ftl;
1184
1185 trans->tr = tr;
1186 trans->mtd = mtd;
1187 trans->devnum = -1;
1188 trans->size = (ftl->block_size * ftl->max_lba * ftl->zone_count) >> 9;
1189 trans->readonly = ftl->readonly;
1190
1191 if (sm_find_cis(ftl)) {
1192 dbg("CIS not found on mtd device, aborting");
1193 goto error6;
1194 }
1195
1196 ftl->disk_attributes = sm_create_sysfs_attributes(ftl);
1197 if (!ftl->disk_attributes)
1198 goto error6;
1199 trans->disk_attributes = ftl->disk_attributes;
1200
1201 sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d",
1202 (int)(mtd->size / (1024 * 1024)), mtd->index);
1203
1204 dbg("FTL layout:");
1205 dbg("%d zone(s), each consists of %d blocks (+%d spares)",
1206 ftl->zone_count, ftl->max_lba,
1207 ftl->zone_size - ftl->max_lba);
1208 dbg("each block consists of %d bytes",
1209 ftl->block_size);
1210
1211
1212 /* Register device*/
1213 if (add_mtd_blktrans_dev(trans)) {
1214 dbg("error in mtdblktrans layer");
1215 goto error6;
1216 }
1217 return;
1218 error6:
1219 kfree(trans);
1220 error5:
1221 kfree(ftl->cache_data);
1222 error4:
1223 kfree(ftl->zones);
1224 error3:
1225 kfree(ftl->cis_buffer);
1226 error2:
1227 kfree(ftl);
1228 error1:
1229 return;
1230 }
1231
1232 /* main interface: device {surprise,} removal */
1233 static void sm_remove_dev(struct mtd_blktrans_dev *dev)
1234 {
1235 struct sm_ftl *ftl = dev->priv;
1236 int i;
1237
1238 del_mtd_blktrans_dev(dev);
1239 ftl->trans = NULL;
1240
1241 for (i = 0 ; i < ftl->zone_count; i++) {
1242
1243 if (!ftl->zones[i].initialized)
1244 continue;
1245
1246 kfree(ftl->zones[i].lba_to_phys_table);
1247 kfifo_free(&ftl->zones[i].free_sectors);
1248 }
1249
1250 sm_delete_sysfs_attributes(ftl);
1251 kfree(ftl->cis_buffer);
1252 kfree(ftl->zones);
1253 kfree(ftl->cache_data);
1254 kfree(ftl);
1255 }
1256
1257 static struct mtd_blktrans_ops sm_ftl_ops = {
1258 .name = "smblk",
1259 .major = -1,
1260 .part_bits = SM_FTL_PARTN_BITS,
1261 .blksize = SM_SECTOR_SIZE,
1262 .getgeo = sm_getgeo,
1263
1264 .add_mtd = sm_add_mtd,
1265 .remove_dev = sm_remove_dev,
1266
1267 .readsect = sm_read,
1268 .writesect = sm_write,
1269
1270 .flush = sm_flush,
1271 .release = sm_release,
1272
1273 .owner = THIS_MODULE,
1274 };
1275
1276 static __init int sm_module_init(void)
1277 {
1278 int error = 0;
1279 cache_flush_workqueue = create_freezable_workqueue("smflush");
1280
1281 if (IS_ERR(cache_flush_workqueue))
1282 return PTR_ERR(cache_flush_workqueue);
1283
1284 error = register_mtd_blktrans(&sm_ftl_ops);
1285 if (error)
1286 destroy_workqueue(cache_flush_workqueue);
1287 return error;
1288
1289 }
1290
1291 static void __exit sm_module_exit(void)
1292 {
1293 destroy_workqueue(cache_flush_workqueue);
1294 deregister_mtd_blktrans(&sm_ftl_ops);
1295 }
1296
1297 module_init(sm_module_init);
1298 module_exit(sm_module_exit);
1299
1300 MODULE_LICENSE("GPL");
1301 MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1302 MODULE_DESCRIPTION("Smartmedia/xD mtd translation layer");
linux-next