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[linux-2.6-block.git] / drivers / mtd / sm_ftl.c
CommitLineData
7d17c02a
ML		 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>
8da552f2 18#include <linux/slab.h>
01de69c2 19#include <linux/mtd/nand_ecc.h>
93db446a 20#include "nand/raw/sm_common.h"
7d17c02a
ML		 21#include "sm_ftl.h"
22
7d17c02a
ML		 23
24
582b2ffc 25static struct workqueue_struct *cache_flush_workqueue;
7d17c02a
ML		 26
27static int cache_timeout = 1000;
f9fbcdc3 28module_param(cache_timeout, int, S_IRUGO);
7d17c02a
ML		 29MODULE_PARM_DESC(cache_timeout,
30 "Timeout (in ms) for cache flush (1000 ms default");
31
32static int debug;
33module_param(debug, int, S_IRUGO | S_IWUSR);
34MODULE_PARM_DESC(debug, "Debug level (0-2)");
35
36
92394b5c 37/* ------------------- sysfs attributes ---------------------------------- */
7d17c02a
ML		 38struct sm_sysfs_attribute {
39 struct device_attribute dev_attr;
40 char *data;
41 int len;
42};
43
582b2ffc 44static ssize_t sm_attr_show(struct device *dev, struct device_attribute *attr,
7d17c02a
ML		 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
582b2ffc 57static struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl)
7d17c02a
ML		 58{
59 struct attribute_group *attr_group;
60 struct attribute **attributes;
61 struct sm_sysfs_attribute *vendor_attribute;
b4c23305 62 char *vendor;
7d17c02a 63
b4c23305
DC		 64 vendor = kstrndup(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET,
65 SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET, GFP_KERNEL);
629286b9
XW		 66 if (!vendor)
67 goto error1;
7d17c02a
ML		 68
69 /* Initialize sysfs attributes */
70 vendor_attribute =
71 kzalloc(sizeof(struct sm_sysfs_attribute), GFP_KERNEL);
629286b9
XW		 72 if (!vendor_attribute)
73 goto error2;
7d17c02a 74
ca7081d9
ML		 75 sysfs_attr_init(&vendor_attribute->dev_attr.attr);
76
7d17c02a 77 vendor_attribute->data = vendor;
b4c23305 78 vendor_attribute->len = strlen(vendor);
7d17c02a
ML		 79 vendor_attribute->dev_attr.attr.name = "vendor";
80 vendor_attribute->dev_attr.attr.mode = S_IRUGO;
81 vendor_attribute->dev_attr.show = sm_attr_show;
82
83
84 /* Create array of pointers to the attributes */
6396bb22 85 attributes = kcalloc(NUM_ATTRIBUTES + 1, sizeof(struct attribute *),
7d17c02a 86 GFP_KERNEL);
629286b9
XW		 87 if (!attributes)
88 goto error3;
7d17c02a
ML		 89 attributes[0] = &vendor_attribute->dev_attr.attr;
90
91 /* Finally create the attribute group */
92 attr_group = kzalloc(sizeof(struct attribute_group), GFP_KERNEL);
629286b9
XW		 93 if (!attr_group)
94 goto error4;
7d17c02a
ML		 95 attr_group->attrs = attributes;
96 return attr_group;
629286b9
XW		 97error4:
98 kfree(attributes);
99error3:
100 kfree(vendor_attribute);
101error2:
102 kfree(vendor);
103error1:
104 return NULL;
7d17c02a
ML		 105}
106
582b2ffc 107static void sm_delete_sysfs_attributes(struct sm_ftl *ftl)
7d17c02a
ML		 108{
109 struct attribute **attributes = ftl->disk_attributes->attrs;
110 int i;
111
112 for (i = 0; attributes[i] ; i++) {
113
114 struct device_attribute *dev_attr = container_of(attributes[i],
115 struct device_attribute, attr);
116
117 struct sm_sysfs_attribute *sm_attr =
118 container_of(dev_attr,
119 struct sm_sysfs_attribute, dev_attr);
120
121 kfree(sm_attr->data);
122 kfree(sm_attr);
123 }
124
125 kfree(ftl->disk_attributes->attrs);
126 kfree(ftl->disk_attributes);
127}
128
129
130/* ----------------------- oob helpers -------------------------------------- */
131
132static int sm_get_lba(uint8_t *lba)
133{
134 /* check fixed bits */
135 if ((lba[0] & 0xF8) != 0x10)
136 return -2;
137
7854d3f7 138 /* check parity - endianness doesn't matter */
7d17c02a
ML		 139 if (hweight16(*(uint16_t *)lba) & 1)
140 return -2;
141
142 return (lba[1] >> 1) | ((lba[0] & 0x07) << 7);
143}
144
145
146/*
92394b5c 147 * Read LBA associated with block
7d17c02a
ML		 148 * returns -1, if block is erased
149 * returns -2 if error happens
150 */
151static int sm_read_lba(struct sm_oob *oob)
152{
153 static const uint32_t erased_pattern[4] = {
154 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
155
156 uint16_t lba_test;
157 int lba;
158
159 /* First test for erased block */
160 if (!memcmp(oob, erased_pattern, SM_OOB_SIZE))
161 return -1;
162
163 /* Now check is both copies of the LBA differ too much */
164 lba_test = *(uint16_t *)oob->lba_copy1 ^ *(uint16_t*)oob->lba_copy2;
165 if (lba_test && !is_power_of_2(lba_test))
166 return -2;
167
168 /* And read it */
169 lba = sm_get_lba(oob->lba_copy1);
170
171 if (lba == -2)
172 lba = sm_get_lba(oob->lba_copy2);
173
174 return lba;
175}
176
177static void sm_write_lba(struct sm_oob *oob, uint16_t lba)
178{
179 uint8_t tmp[2];
180
181 WARN_ON(lba >= 1000);
182
183 tmp[0] = 0x10 | ((lba >> 7) & 0x07);
184 tmp[1] = (lba << 1) & 0xFF;
185
186 if (hweight16(*(uint16_t *)tmp) & 0x01)
187 tmp[1] |= 1;
188
189 oob->lba_copy1[0] = oob->lba_copy2[0] = tmp[0];
190 oob->lba_copy1[1] = oob->lba_copy2[1] = tmp[1];
191}
192
193
194/* Make offset from parts */
195static loff_t sm_mkoffset(struct sm_ftl *ftl, int zone, int block, int boffset)
196{
197 WARN_ON(boffset & (SM_SECTOR_SIZE - 1));
198 WARN_ON(zone < 0 || zone >= ftl->zone_count);
199 WARN_ON(block >= ftl->zone_size);
200 WARN_ON(boffset >= ftl->block_size);
201
202 if (block == -1)
203 return -1;
204
205 return (zone * SM_MAX_ZONE_SIZE + block) * ftl->block_size + boffset;
206}
207
208/* Breaks offset into parts */
2b2462d5 209static void sm_break_offset(struct sm_ftl *ftl, loff_t loffset,
7d17c02a
ML		 210 int *zone, int *block, int *boffset)
211{
2b2462d5 212 u64 offset = loffset;
7d17c02a
ML		 213 *boffset = do_div(offset, ftl->block_size);
214 *block = do_div(offset, ftl->max_lba);
215 *zone = offset >= ftl->zone_count ? -1 : offset;
216}
217
218/* ---------------------- low level IO ------------------------------------- */
219
220static int sm_correct_sector(uint8_t *buffer, struct sm_oob *oob)
221{
7d17c02a
ML		 222 uint8_t ecc[3];
223
309600c1
BB		 224 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc,
225 IS_ENABLED(CONFIG_MTD_NAND_ECC_SMC));
226 if (__nand_correct_data(buffer, ecc, oob->ecc1, SM_SMALL_PAGE,
227 IS_ENABLED(CONFIG_MTD_NAND_ECC_SMC)) < 0)
7d17c02a
ML		 228 return -EIO;
229
230 buffer += SM_SMALL_PAGE;
231
309600c1
BB		 232 __nand_calculate_ecc(buffer, SM_SMALL_PAGE, ecc,
233 IS_ENABLED(CONFIG_MTD_NAND_ECC_SMC));
234 if (__nand_correct_data(buffer, ecc, oob->ecc2, SM_SMALL_PAGE,
235 IS_ENABLED(CONFIG_MTD_NAND_ECC_SMC)) < 0)
7d17c02a 236 return -EIO;
7d17c02a
ML		 237 return 0;
238}
239
240/* Reads a sector + oob*/
241static int sm_read_sector(struct sm_ftl *ftl,
242 int zone, int block, int boffset,
243 uint8_t *buffer, struct sm_oob *oob)
244{
245 struct mtd_info *mtd = ftl->trans->mtd;
246 struct mtd_oob_ops ops;
247 struct sm_oob tmp_oob;
133fa8c7 248 int ret = -EIO;
7d17c02a
ML		 249 int try = 0;
250
251 /* FTL can contain -1 entries that are by default filled with bits */
252 if (block == -1) {
253 memset(buffer, 0xFF, SM_SECTOR_SIZE);
254 return 0;
255 }
256
92394b5c 257 /* User might not need the oob, but we do for data verification */
7d17c02a
ML		 258 if (!oob)
259 oob = &tmp_oob;
260
0612b9dd 261 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB;
7d17c02a
ML		 262 ops.ooboffs = 0;
263 ops.ooblen = SM_OOB_SIZE;
264 ops.oobbuf = (void *)oob;
265 ops.len = SM_SECTOR_SIZE;
266 ops.datbuf = buffer;
267
268again:
269 if (try++) {
270 /* Avoid infinite recursion on CIS reads, sm_recheck_media
271 won't help anyway */
272 if (zone == 0 && block == ftl->cis_block && boffset ==
273 ftl->cis_boffset)
274 return ret;
275
276 /* Test if media is stable */
277 if (try == 3 || sm_recheck_media(ftl))
278 return ret;
279 }
280
92394b5c 281 /* Unfortunately, oob read will _always_ succeed,
7d17c02a 282 despite card removal..... */
fd2819bb 283 ret = mtd_read_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops);
7d17c02a
ML		 284
285 /* Test for unknown errors */
d57f4054 286 if (ret != 0 && !mtd_is_bitflip_or_eccerr(ret)) {
7d17c02a
ML		 287 dbg("read of block %d at zone %d, failed due to error (%d)",
288 block, zone, ret);
289 goto again;
290 }
291
292 /* Do a basic test on the oob, to guard against returned garbage */
293 if (oob->reserved != 0xFFFFFFFF && !is_power_of_2(~oob->reserved))
294 goto again;
295
296 /* This should never happen, unless there is a bug in the mtd driver */
297 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
298 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
299
300 if (!buffer)
301 return 0;
302
303 /* Test if sector marked as bad */
304 if (!sm_sector_valid(oob)) {
305 dbg("read of block %d at zone %d, failed because it is marked"
306 " as bad" , block, zone);
307 goto again;
308 }
309
310 /* Test ECC*/
d57f4054 311 if (mtd_is_eccerr(ret) ||
7d17c02a
ML		 312 (ftl->smallpagenand && sm_correct_sector(buffer, oob))) {
313
314 dbg("read of block %d at zone %d, failed due to ECC error",
315 block, zone);
316 goto again;
317 }
318
319 return 0;
320}
321
322/* Writes a sector to media */
323static int sm_write_sector(struct sm_ftl *ftl,
324 int zone, int block, int boffset,
325 uint8_t *buffer, struct sm_oob *oob)
326{
327 struct mtd_oob_ops ops;
328 struct mtd_info *mtd = ftl->trans->mtd;
329 int ret;
330
331 BUG_ON(ftl->readonly);
332
333 if (zone == 0 && (block == ftl->cis_block || block == 0)) {
334 dbg("attempted to write the CIS!");
335 return -EIO;
336 }
337
338 if (ftl->unstable)
339 return -EIO;
340
0612b9dd 341 ops.mode = ftl->smallpagenand ? MTD_OPS_RAW : MTD_OPS_PLACE_OOB;
7d17c02a
ML		 342 ops.len = SM_SECTOR_SIZE;
343 ops.datbuf = buffer;
344 ops.ooboffs = 0;
345 ops.ooblen = SM_OOB_SIZE;
346 ops.oobbuf = (void *)oob;
347
a2cc5ba0 348 ret = mtd_write_oob(mtd, sm_mkoffset(ftl, zone, block, boffset), &ops);
7d17c02a
ML		 349
350 /* Now we assume that hardware will catch write bitflip errors */
7d17c02a
ML		 351
352 if (ret) {
353 dbg("write to block %d at zone %d, failed with error %d",
354 block, zone, ret);
355
356 sm_recheck_media(ftl);
357 return ret;
358 }
359
360 /* This should never happen, unless there is a bug in the driver */
361 WARN_ON(ops.oobretlen != SM_OOB_SIZE);
362 WARN_ON(buffer && ops.retlen != SM_SECTOR_SIZE);
363
364 return 0;
365}
366
367/* ------------------------ block IO ------------------------------------- */
368
369/* Write a block using data and lba, and invalid sector bitmap */
370static int sm_write_block(struct sm_ftl *ftl, uint8_t *buf,
371 int zone, int block, int lba,
372 unsigned long invalid_bitmap)
373{
374 struct sm_oob oob;
375 int boffset;
376 int retry = 0;
377
378 /* Initialize the oob with requested values */
379 memset(&oob, 0xFF, SM_OOB_SIZE);
380 sm_write_lba(&oob, lba);
381restart:
382 if (ftl->unstable)
383 return -EIO;
384
385 for (boffset = 0; boffset < ftl->block_size;
386 boffset += SM_SECTOR_SIZE) {
387
388 oob.data_status = 0xFF;
389
390 if (test_bit(boffset / SM_SECTOR_SIZE, &invalid_bitmap)) {
391
392 sm_printk("sector %d of block at LBA %d of zone %d"
c19ca6cb 393 " couldn't be read, marking it as invalid",
7d17c02a
ML		 394 boffset / SM_SECTOR_SIZE, lba, zone);
395
396 oob.data_status = 0;
397 }
398
7d17c02a 399 if (ftl->smallpagenand) {
309600c1
BB		 400 __nand_calculate_ecc(buf + boffset, SM_SMALL_PAGE,
401 oob.ecc1,
402 IS_ENABLED(CONFIG_MTD_NAND_ECC_SMC));
7d17c02a
ML		 403
404 __nand_calculate_ecc(buf + boffset + SM_SMALL_PAGE,
309600c1
BB		 405 SM_SMALL_PAGE, oob.ecc2,
406 IS_ENABLED(CONFIG_MTD_NAND_ECC_SMC));
7d17c02a 407 }
7d17c02a
ML		 408 if (!sm_write_sector(ftl, zone, block, boffset,
409 buf + boffset, &oob))
410 continue;
411
412 if (!retry) {
413
414 /* If write fails. try to erase the block */
415 /* This is safe, because we never write in blocks
416 that contain valuable data.
417 This is intended to repair block that are marked
418 as erased, but that isn't fully erased*/
419
420 if (sm_erase_block(ftl, zone, block, 0))
421 return -EIO;
422
423 retry = 1;
424 goto restart;
425 } else {
426 sm_mark_block_bad(ftl, zone, block);
427 return -EIO;
428 }
429 }
430 return 0;
431}
432
433
434/* Mark whole block at offset 'offs' as bad. */
435static void sm_mark_block_bad(struct sm_ftl *ftl, int zone, int block)
436{
437 struct sm_oob oob;
438 int boffset;
439
440 memset(&oob, 0xFF, SM_OOB_SIZE);
441 oob.block_status = 0xF0;
442
443 if (ftl->unstable)
444 return;
445
446 if (sm_recheck_media(ftl))
447 return;
448
449 sm_printk("marking block %d of zone %d as bad", block, zone);
450
451 /* We aren't checking the return value, because we don't care */
452 /* This also fails on fake xD cards, but I guess these won't expose
92394b5c 453 any bad blocks till fail completely */
7d17c02a
ML		 454 for (boffset = 0; boffset < ftl->block_size; boffset += SM_SECTOR_SIZE)
455 sm_write_sector(ftl, zone, block, boffset, NULL, &oob);
456}
457
458/*
459 * Erase a block within a zone
92394b5c 460 * If erase succeeds, it updates free block fifo, otherwise marks block as bad
7d17c02a
ML		 461 */
462static int sm_erase_block(struct sm_ftl *ftl, int zone_num, uint16_t block,
463 int put_free)
464{
465 struct ftl_zone *zone = &ftl->zones[zone_num];
466 struct mtd_info *mtd = ftl->trans->mtd;
467 struct erase_info erase;
468
7d17c02a
ML		 469 erase.addr = sm_mkoffset(ftl, zone_num, block, 0);
470 erase.len = ftl->block_size;
7d17c02a
ML		 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
7e1f0dc0 482 if (mtd_erase(mtd, &erase)) {
7d17c02a
ML		 483 sm_printk("erase of block %d in zone %d failed",
484 block, zone_num);
485 goto error;
486 }
487
7d17c02a
ML		 488 if (put_free)
489 kfifo_in(&zone->free_sectors,
490 (const unsigned char *)&block, sizeof(block));
491
492 return 0;
493error:
494 sm_mark_block_bad(ftl, zone_num, block);
495 return -EIO;
496}
497
92394b5c 498/* Thoroughly test that block is valid. */
7d17c02a
ML		 499static int sm_check_block(struct sm_ftl *ftl, int zone, int block)
500{
501 int boffset;
502 struct sm_oob oob;
503 int lbas[] = { -3, 0, 0, 0 };
504 int i = 0;
505 int test_lba;
506
507
508 /* First just check that block doesn't look fishy */
509 /* Only blocks that are valid or are sliced in two parts, are
510 accepted */
511 for (boffset = 0; boffset < ftl->block_size;
512 boffset += SM_SECTOR_SIZE) {
513
92394b5c 514 /* This shouldn't happen anyway */
7d17c02a
ML		 515 if (sm_read_sector(ftl, zone, block, boffset, NULL, &oob))
516 return -2;
517
518 test_lba = sm_read_lba(&oob);
519
520 if (lbas[i] != test_lba)
521 lbas[++i] = test_lba;
522
523 /* If we found three different LBAs, something is fishy */
524 if (i == 3)
525 return -EIO;
526 }
527
25985edc 528 /* If the block is sliced (partially erased usually) erase it */
7d17c02a
ML		 529 if (i == 2) {
530 sm_erase_block(ftl, zone, block, 1);
531 return 1;
532 }
533
534 return 0;
535}
536
537/* ----------------- media scanning --------------------------------- */
538static const struct chs_entry chs_table[] = {
539 { 1, 125, 4, 4 },
540 { 2, 125, 4, 8 },
541 { 4, 250, 4, 8 },
542 { 8, 250, 4, 16 },
543 { 16, 500, 4, 16 },
544 { 32, 500, 8, 16 },
545 { 64, 500, 8, 32 },
546 { 128, 500, 16, 32 },
547 { 256, 1000, 16, 32 },
548 { 512, 1015, 32, 63 },
549 { 1024, 985, 33, 63 },
550 { 2048, 985, 33, 63 },
551 { 0 },
552};
553
554
555static const uint8_t cis_signature[] = {
556 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20
557};
558/* Find out media parameters.
559 * This ideally has to be based on nand id, but for now device size is enough */
582b2ffc 560static int sm_get_media_info(struct sm_ftl *ftl, struct mtd_info *mtd)
7d17c02a
ML		 561{
562 int i;
563 int size_in_megs = mtd->size / (1024 * 1024);
564
565 ftl->readonly = mtd->type == MTD_ROM;
566
567 /* Manual settings for very old devices */
568 ftl->zone_count = 1;
569 ftl->smallpagenand = 0;
570
571 switch (size_in_megs) {
572 case 1:
573 /* 1 MiB flash/rom SmartMedia card (256 byte pages)*/
574 ftl->zone_size = 256;
575 ftl->max_lba = 250;
576 ftl->block_size = 8 * SM_SECTOR_SIZE;
577 ftl->smallpagenand = 1;
578
579 break;
580 case 2:
581 /* 2 MiB flash SmartMedia (256 byte pages)*/
582 if (mtd->writesize == SM_SMALL_PAGE) {
583 ftl->zone_size = 512;
584 ftl->max_lba = 500;
585 ftl->block_size = 8 * SM_SECTOR_SIZE;
586 ftl->smallpagenand = 1;
587 /* 2 MiB rom SmartMedia */
588 } else {
589
590 if (!ftl->readonly)
591 return -ENODEV;
592
593 ftl->zone_size = 256;
594 ftl->max_lba = 250;
595 ftl->block_size = 16 * SM_SECTOR_SIZE;
596 }
597 break;
598 case 4:
599 /* 4 MiB flash/rom SmartMedia device */
600 ftl->zone_size = 512;
601 ftl->max_lba = 500;
602 ftl->block_size = 16 * SM_SECTOR_SIZE;
603 break;
604 case 8:
605 /* 8 MiB flash/rom SmartMedia device */
606 ftl->zone_size = 1024;
607 ftl->max_lba = 1000;
608 ftl->block_size = 16 * SM_SECTOR_SIZE;
609 }
610
611 /* Minimum xD size is 16MiB. Also, all xD cards have standard zone
612 sizes. SmartMedia cards exist up to 128 MiB and have same layout*/
613 if (size_in_megs >= 16) {
614 ftl->zone_count = size_in_megs / 16;
615 ftl->zone_size = 1024;
616 ftl->max_lba = 1000;
617 ftl->block_size = 32 * SM_SECTOR_SIZE;
618 }
619
620 /* Test for proper write,erase and oob sizes */
621 if (mtd->erasesize > ftl->block_size)
622 return -ENODEV;
623
624 if (mtd->writesize > SM_SECTOR_SIZE)
625 return -ENODEV;
626
627 if (ftl->smallpagenand && mtd->oobsize < SM_SMALL_OOB_SIZE)
628 return -ENODEV;
629
630 if (!ftl->smallpagenand && mtd->oobsize < SM_OOB_SIZE)
631 return -ENODEV;
632
fc002e3c
AB		 633 /* We use OOB */
634 if (!mtd_has_oob(mtd))
7d17c02a
ML		 635 return -ENODEV;
636
637 /* Find geometry information */
638 for (i = 0 ; i < ARRAY_SIZE(chs_table) ; i++) {
639 if (chs_table[i].size == size_in_megs) {
640 ftl->cylinders = chs_table[i].cyl;
641 ftl->heads = chs_table[i].head;
642 ftl->sectors = chs_table[i].sec;
643 return 0;
644 }
645 }
646
647 sm_printk("media has unknown size : %dMiB", size_in_megs);
648 ftl->cylinders = 985;
649 ftl->heads = 33;
650 ftl->sectors = 63;
651 return 0;
652}
653
654/* Validate the CIS */
655static int sm_read_cis(struct sm_ftl *ftl)
656{
657 struct sm_oob oob;
658
659 if (sm_read_sector(ftl,
660 0, ftl->cis_block, ftl->cis_boffset, ftl->cis_buffer, &oob))
661 return -EIO;
662
663 if (!sm_sector_valid(&oob) || !sm_block_valid(&oob))
664 return -EIO;
665
666 if (!memcmp(ftl->cis_buffer + ftl->cis_page_offset,
667 cis_signature, sizeof(cis_signature))) {
668 return 0;
669 }
670
671 return -EIO;
672}
673
674/* Scan the media for the CIS */
675static int sm_find_cis(struct sm_ftl *ftl)
676{
677 struct sm_oob oob;
678 int block, boffset;
679 int block_found = 0;
680 int cis_found = 0;
681
682 /* Search for first valid block */
683 for (block = 0 ; block < ftl->zone_size - ftl->max_lba ; block++) {
684
685 if (sm_read_sector(ftl, 0, block, 0, NULL, &oob))
686 continue;
687
688 if (!sm_block_valid(&oob))
689 continue;
690 block_found = 1;
691 break;
692 }
693
694 if (!block_found)
695 return -EIO;
696
697 /* Search for first valid sector in this block */
698 for (boffset = 0 ; boffset < ftl->block_size;
699 boffset += SM_SECTOR_SIZE) {
700
701 if (sm_read_sector(ftl, 0, block, boffset, NULL, &oob))
702 continue;
703
704 if (!sm_sector_valid(&oob))
705 continue;
706 break;
707 }
708
709 if (boffset == ftl->block_size)
710 return -EIO;
711
712 ftl->cis_block = block;
713 ftl->cis_boffset = boffset;
714 ftl->cis_page_offset = 0;
715
716 cis_found = !sm_read_cis(ftl);
717
718 if (!cis_found) {
719 ftl->cis_page_offset = SM_SMALL_PAGE;
720 cis_found = !sm_read_cis(ftl);
721 }
722
723 if (cis_found) {
724 dbg("CIS block found at offset %x",
725 block * ftl->block_size +
726 boffset + ftl->cis_page_offset);
727 return 0;
728 }
729 return -EIO;
730}
731
732/* Basic test to determine if underlying mtd device if functional */
733static int sm_recheck_media(struct sm_ftl *ftl)
734{
735 if (sm_read_cis(ftl)) {
736
737 if (!ftl->unstable) {
738 sm_printk("media unstable, not allowing writes");
739 ftl->unstable = 1;
740 }
741 return -EIO;
742 }
743 return 0;
744}
745
746/* Initialize a FTL zone */
747static int sm_init_zone(struct sm_ftl *ftl, int zone_num)
748{
749 struct ftl_zone *zone = &ftl->zones[zone_num];
750 struct sm_oob oob;
751 uint16_t block;
752 int lba;
753 int i = 0;
133fa8c7 754 int len;
7d17c02a
ML		 755
756 dbg("initializing zone %d", zone_num);
757
758 /* Allocate memory for FTL table */
6da2ec56 759 zone->lba_to_phys_table = kmalloc_array(ftl->max_lba, 2, GFP_KERNEL);
7d17c02a
ML		 760
761 if (!zone->lba_to_phys_table)
762 return -ENOMEM;
763 memset(zone->lba_to_phys_table, -1, ftl->max_lba * 2);
764
765
766 /* Allocate memory for free sectors FIFO */
767 if (kfifo_alloc(&zone->free_sectors, ftl->zone_size * 2, GFP_KERNEL)) {
768 kfree(zone->lba_to_phys_table);
769 return -ENOMEM;
770 }
771
772 /* Now scan the zone */
773 for (block = 0 ; block < ftl->zone_size ; block++) {
774
775 /* Skip blocks till the CIS (including) */
776 if (zone_num == 0 && block <= ftl->cis_block)
777 continue;
778
779 /* Read the oob of first sector */
780 if (sm_read_sector(ftl, zone_num, block, 0, NULL, &oob))
781 return -EIO;
782
783 /* Test to see if block is erased. It is enough to test
784 first sector, because erase happens in one shot */
785 if (sm_block_erased(&oob)) {
786 kfifo_in(&zone->free_sectors,
787 (unsigned char *)&block, 2);
788 continue;
789 }
790
791 /* If block is marked as bad, skip it */
792 /* This assumes we can trust first sector*/
793 /* However the way the block valid status is defined, ensures
794 very low probability of failure here */
795 if (!sm_block_valid(&oob)) {
796 dbg("PH %04d <-> <marked bad>", block);
797 continue;
798 }
799
800
801 lba = sm_read_lba(&oob);
802
803 /* Invalid LBA means that block is damaged. */
804 /* We can try to erase it, or mark it as bad, but
805 lets leave that to recovery application */
806 if (lba == -2 || lba >= ftl->max_lba) {
807 dbg("PH %04d <-> LBA %04d(bad)", block, lba);
808 continue;
809 }
810
811
812 /* If there is no collision,
813 just put the sector in the FTL table */
814 if (zone->lba_to_phys_table[lba] < 0) {
815 dbg_verbose("PH %04d <-> LBA %04d", block, lba);
816 zone->lba_to_phys_table[lba] = block;
817 continue;
818 }
819
820 sm_printk("collision"
821 " of LBA %d between blocks %d and %d in zone %d",
822 lba, zone->lba_to_phys_table[lba], block, zone_num);
823
824 /* Test that this block is valid*/
825 if (sm_check_block(ftl, zone_num, block))
826 continue;
827
828 /* Test now the old block */
829 if (sm_check_block(ftl, zone_num,
830 zone->lba_to_phys_table[lba])) {
831 zone->lba_to_phys_table[lba] = block;
832 continue;
833 }
834
835 /* If both blocks are valid and share same LBA, it means that
836 they hold different versions of same data. It not
837 known which is more recent, thus just erase one of them
838 */
839 sm_printk("both blocks are valid, erasing the later");
840 sm_erase_block(ftl, zone_num, block, 1);
841 }
842
843 dbg("zone initialized");
844 zone->initialized = 1;
845
846 /* No free sectors, means that the zone is heavily damaged, write won't
847 work, but it can still can be (partially) read */
848 if (!kfifo_len(&zone->free_sectors)) {
849 sm_printk("no free blocks in zone %d", zone_num);
850 return 0;
851 }
852
853 /* Randomize first block we write to */
854 get_random_bytes(&i, 2);
855 i %= (kfifo_len(&zone->free_sectors) / 2);
856
857 while (i--) {
133fa8c7
ML		 858 len = kfifo_out(&zone->free_sectors,
859 (unsigned char *)&block, 2);
860 WARN_ON(len != 2);
7d17c02a
ML		 861 kfifo_in(&zone->free_sectors, (const unsigned char *)&block, 2);
862 }
863 return 0;
864}
865
25985edc 866/* Get and automatically initialize an FTL mapping for one zone */
582b2ffc 867static struct ftl_zone *sm_get_zone(struct sm_ftl *ftl, int zone_num)
7d17c02a
ML		 868{
869 struct ftl_zone *zone;
870 int error;
871
872 BUG_ON(zone_num >= ftl->zone_count);
873 zone = &ftl->zones[zone_num];
874
875 if (!zone->initialized) {
876 error = sm_init_zone(ftl, zone_num);
877
878 if (error)
879 return ERR_PTR(error);
880 }
881 return zone;
882}
883
884
885/* ----------------- cache handling ------------------------------------------*/
886
887/* Initialize the one block cache */
582b2ffc 888static void sm_cache_init(struct sm_ftl *ftl)
7d17c02a
ML		 889{
890 ftl->cache_data_invalid_bitmap = 0xFFFFFFFF;
891 ftl->cache_clean = 1;
892 ftl->cache_zone = -1;
893 ftl->cache_block = -1;
894 /*memset(ftl->cache_data, 0xAA, ftl->block_size);*/
895}
896
897/* Put sector in one block cache */
582b2ffc 898static void sm_cache_put(struct sm_ftl *ftl, char *buffer, int boffset)
7d17c02a
ML		 899{
900 memcpy(ftl->cache_data + boffset, buffer, SM_SECTOR_SIZE);
901 clear_bit(boffset / SM_SECTOR_SIZE, &ftl->cache_data_invalid_bitmap);
902 ftl->cache_clean = 0;
903}
904
905/* Read a sector from the cache */
582b2ffc 906static int sm_cache_get(struct sm_ftl *ftl, char *buffer, int boffset)
7d17c02a
ML		 907{
908 if (test_bit(boffset / SM_SECTOR_SIZE,
909 &ftl->cache_data_invalid_bitmap))
910 return -1;
911
912 memcpy(buffer, ftl->cache_data + boffset, SM_SECTOR_SIZE);
913 return 0;
914}
915
916/* Write the cache to hardware */
582b2ffc 917static int sm_cache_flush(struct sm_ftl *ftl)
7d17c02a
ML		 918{
919 struct ftl_zone *zone;
920
921 int sector_num;
922 uint16_t write_sector;
923 int zone_num = ftl->cache_zone;
924 int block_num;
925
926 if (ftl->cache_clean)
927 return 0;
928
929 if (ftl->unstable)
930 return -EIO;
931
932 BUG_ON(zone_num < 0);
933 zone = &ftl->zones[zone_num];
934 block_num = zone->lba_to_phys_table[ftl->cache_block];
935
936
937 /* Try to read all unread areas of the cache block*/
fed457a8 938 for_each_set_bit(sector_num, &ftl->cache_data_invalid_bitmap,
7d17c02a
ML		 939 ftl->block_size / SM_SECTOR_SIZE) {
940
941 if (!sm_read_sector(ftl,
942 zone_num, block_num, sector_num * SM_SECTOR_SIZE,
943 ftl->cache_data + sector_num * SM_SECTOR_SIZE, NULL))
944 clear_bit(sector_num,
945 &ftl->cache_data_invalid_bitmap);
946 }
947restart:
948
949 if (ftl->unstable)
950 return -EIO;
133fa8c7
ML		 951
952 /* If there are no spare blocks, */
953 /* we could still continue by erasing/writing the current block,
7d17c02a
ML		 954 but for such worn out media it doesn't worth the trouble,
955 and the dangers */
133fa8c7
ML		 956 if (kfifo_out(&zone->free_sectors,
957 (unsigned char *)&write_sector, 2) != 2) {
7d17c02a
ML		 958 dbg("no free sectors for write!");
959 return -EIO;
960 }
961
7d17c02a
ML		 962
963 if (sm_write_block(ftl, ftl->cache_data, zone_num, write_sector,
964 ftl->cache_block, ftl->cache_data_invalid_bitmap))
965 goto restart;
966
967 /* Update the FTL table */
968 zone->lba_to_phys_table[ftl->cache_block] = write_sector;
969
970 /* Write succesfull, so erase and free the old block */
971 if (block_num > 0)
972 sm_erase_block(ftl, zone_num, block_num, 1);
973
974 sm_cache_init(ftl);
975 return 0;
976}
977
978
979/* flush timer, runs a second after last write */
e99e88a9 980static void sm_cache_flush_timer(struct timer_list *t)
7d17c02a 981{
e99e88a9 982 struct sm_ftl *ftl = from_timer(ftl, t, timer);
7d17c02a
ML		 983 queue_work(cache_flush_workqueue, &ftl->flush_work);
984}
985
986/* cache flush work, kicked by timer */
987static void sm_cache_flush_work(struct work_struct *work)
988{
989 struct sm_ftl *ftl = container_of(work, struct sm_ftl, flush_work);
990 mutex_lock(&ftl->mutex);
991 sm_cache_flush(ftl);
992 mutex_unlock(&ftl->mutex);
993 return;
994}
995
996/* ---------------- outside interface -------------------------------------- */
997
998/* outside interface: read a sector */
999static int sm_read(struct mtd_blktrans_dev *dev,
1000 unsigned long sect_no, char *buf)
1001{
1002 struct sm_ftl *ftl = dev->priv;
1003 struct ftl_zone *zone;
1004 int error = 0, in_cache = 0;
1005 int zone_num, block, boffset;
1006
1007 sm_break_offset(ftl, sect_no << 9, &zone_num, &block, &boffset);
1008 mutex_lock(&ftl->mutex);
1009
1010
1011 zone = sm_get_zone(ftl, zone_num);
1012 if (IS_ERR(zone)) {
1013 error = PTR_ERR(zone);
1014 goto unlock;
1015 }
1016
1017 /* Have to look at cache first */
1018 if (ftl->cache_zone == zone_num && ftl->cache_block == block) {
1019 in_cache = 1;
1020 if (!sm_cache_get(ftl, buf, boffset))
1021 goto unlock;
1022 }
1023
1024 /* Translate the block and return if doesn't exist in the table */
1025 block = zone->lba_to_phys_table[block];
1026
1027 if (block == -1) {
1028 memset(buf, 0xFF, SM_SECTOR_SIZE);
1029 goto unlock;
1030 }
1031
1032 if (sm_read_sector(ftl, zone_num, block, boffset, buf, NULL)) {
1033 error = -EIO;
1034 goto unlock;
1035 }
1036
1037 if (in_cache)
1038 sm_cache_put(ftl, buf, boffset);
1039unlock:
1040 mutex_unlock(&ftl->mutex);
1041 return error;
1042}
1043
1044/* outside interface: write a sector */
1045static int sm_write(struct mtd_blktrans_dev *dev,
1046 unsigned long sec_no, char *buf)
1047{
1048 struct sm_ftl *ftl = dev->priv;
1049 struct ftl_zone *zone;
f7f0d358 1050 int error = 0, zone_num, block, boffset;
7d17c02a
ML		 1051
1052 BUG_ON(ftl->readonly);
1053 sm_break_offset(ftl, sec_no << 9, &zone_num, &block, &boffset);
1054
1055 /* No need in flush thread running now */
1056 del_timer(&ftl->timer);
1057 mutex_lock(&ftl->mutex);
1058
1059 zone = sm_get_zone(ftl, zone_num);
1060 if (IS_ERR(zone)) {
1061 error = PTR_ERR(zone);
1062 goto unlock;
1063 }
1064
1065 /* If entry is not in cache, flush it */
1066 if (ftl->cache_block != block || ftl->cache_zone != zone_num) {
1067
1068 error = sm_cache_flush(ftl);
1069 if (error)
1070 goto unlock;
1071
1072 ftl->cache_block = block;
1073 ftl->cache_zone = zone_num;
1074 }
1075
1076 sm_cache_put(ftl, buf, boffset);
1077unlock:
1078 mod_timer(&ftl->timer, jiffies + msecs_to_jiffies(cache_timeout));
1079 mutex_unlock(&ftl->mutex);
1080 return error;
1081}
1082
1083/* outside interface: flush everything */
1084static int sm_flush(struct mtd_blktrans_dev *dev)
1085{
1086 struct sm_ftl *ftl = dev->priv;
1087 int retval;
1088
1089 mutex_lock(&ftl->mutex);
1090 retval = sm_cache_flush(ftl);
1091 mutex_unlock(&ftl->mutex);
1092 return retval;
1093}
1094
1095/* outside interface: device is released */
a8ca889e 1096static void sm_release(struct mtd_blktrans_dev *dev)
7d17c02a
ML		 1097{
1098 struct sm_ftl *ftl = dev->priv;
1099
1100 mutex_lock(&ftl->mutex);
1101 del_timer_sync(&ftl->timer);
1102 cancel_work_sync(&ftl->flush_work);
1103 sm_cache_flush(ftl);
1104 mutex_unlock(&ftl->mutex);
7d17c02a
ML		 1105}
1106
1107/* outside interface: get geometry */
1108static 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 */
1118static 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);
e99e88a9 1130 timer_setup(&ftl->timer, sm_cache_flush_timer, 0);
7d17c02a 1131 INIT_WORK(&ftl->flush_work, sm_cache_flush_work);
7d17c02a
ML		 1132
1133 /* Read media information */
1134 if (sm_get_media_info(ftl, mtd)) {
1135 dbg("found unsupported mtd device, aborting");
1136 goto error2;
1137 }
1138
1139
1140 /* Allocate temporary CIS buffer for read retry support */
1141 ftl->cis_buffer = kzalloc(SM_SECTOR_SIZE, GFP_KERNEL);
1142 if (!ftl->cis_buffer)
1143 goto error2;
1144
1145 /* Allocate zone array, it will be initialized on demand */
6396bb22 1146 ftl->zones = kcalloc(ftl->zone_count, sizeof(struct ftl_zone),
7d17c02a
ML		 1147 GFP_KERNEL);
1148 if (!ftl->zones)
1149 goto error3;
1150
1151 /* Allocate the cache*/
1152 ftl->cache_data = kzalloc(ftl->block_size, GFP_KERNEL);
1153
1154 if (!ftl->cache_data)
1155 goto error4;
1156
1157 sm_cache_init(ftl);
1158
1159
1160 /* Allocate upper layer structure and initialize it */
1161 trans = kzalloc(sizeof(struct mtd_blktrans_dev), GFP_KERNEL);
1162 if (!trans)
1163 goto error5;
1164
1165 ftl->trans = trans;
1166 trans->priv = ftl;
1167
1168 trans->tr = tr;
1169 trans->mtd = mtd;
1170 trans->devnum = -1;
1171 trans->size = (ftl->block_size * ftl->max_lba * ftl->zone_count) >> 9;
1172 trans->readonly = ftl->readonly;
1173
1174 if (sm_find_cis(ftl)) {
1175 dbg("CIS not found on mtd device, aborting");
1176 goto error6;
1177 }
1178
1179 ftl->disk_attributes = sm_create_sysfs_attributes(ftl);
629286b9
XW		 1180 if (!ftl->disk_attributes)
1181 goto error6;
7d17c02a
ML		 1182 trans->disk_attributes = ftl->disk_attributes;
1183
1184 sm_printk("Found %d MiB xD/SmartMedia FTL on mtd%d",
1185 (int)(mtd->size / (1024 * 1024)), mtd->index);
1186
1187 dbg("FTL layout:");
1188 dbg("%d zone(s), each consists of %d blocks (+%d spares)",
1189 ftl->zone_count, ftl->max_lba,
1190 ftl->zone_size - ftl->max_lba);
1191 dbg("each block consists of %d bytes",
1192 ftl->block_size);
1193
1194
1195 /* Register device*/
1196 if (add_mtd_blktrans_dev(trans)) {
1197 dbg("error in mtdblktrans layer");
1198 goto error6;
1199 }
1200 return;
1201error6:
1202 kfree(trans);
1203error5:
1204 kfree(ftl->cache_data);
1205error4:
1206 kfree(ftl->zones);
1207error3:
1208 kfree(ftl->cis_buffer);
1209error2:
1210 kfree(ftl);
1211error1:
1212 return;
1213}
1214
1215/* main interface: device {surprise,} removal */
1216static void sm_remove_dev(struct mtd_blktrans_dev *dev)
1217{
1218 struct sm_ftl *ftl = dev->priv;
1219 int i;
1220
1221 del_mtd_blktrans_dev(dev);
1222 ftl->trans = NULL;
1223
1224 for (i = 0 ; i < ftl->zone_count; i++) {
1225
1226 if (!ftl->zones[i].initialized)
1227 continue;
1228
1229 kfree(ftl->zones[i].lba_to_phys_table);
1230 kfifo_free(&ftl->zones[i].free_sectors);
1231 }
1232
1233 sm_delete_sysfs_attributes(ftl);
1234 kfree(ftl->cis_buffer);
1235 kfree(ftl->zones);
1236 kfree(ftl->cache_data);
1237 kfree(ftl);
1238}
1239
1240static struct mtd_blktrans_ops sm_ftl_ops = {
1241 .name = "smblk",
452380ef 1242 .major = 0,
7d17c02a
ML		 1243 .part_bits = SM_FTL_PARTN_BITS,
1244 .blksize = SM_SECTOR_SIZE,
1245 .getgeo = sm_getgeo,
1246
1247 .add_mtd = sm_add_mtd,
1248 .remove_dev = sm_remove_dev,
1249
1250 .readsect = sm_read,
1251 .writesect = sm_write,
1252
1253 .flush = sm_flush,
1254 .release = sm_release,
1255
1256 .owner = THIS_MODULE,
1257};
1258
1259static __init int sm_module_init(void)
1260{
1261 int error = 0;
7d17c02a 1262
39de86ef
DC		 1263 cache_flush_workqueue = create_freezable_workqueue("smflush");
1264 if (!cache_flush_workqueue)
1265 return -ENOMEM;
7d17c02a
ML		 1266
1267 error = register_mtd_blktrans(&sm_ftl_ops);
1268 if (error)
1269 destroy_workqueue(cache_flush_workqueue);
1270 return error;
1271
1272}
1273
1274static void __exit sm_module_exit(void)
1275{
1276 destroy_workqueue(cache_flush_workqueue);
1277 deregister_mtd_blktrans(&sm_ftl_ops);
1278}
1279
1280module_init(sm_module_init);
1281module_exit(sm_module_exit);
1282
1283MODULE_LICENSE("GPL");
1284MODULE_AUTHOR("Maxim Levitsky <maximlevitsky@gmail.com>");
1285MODULE_DESCRIPTION("Smartmedia/xD mtd translation layer");
Linux 6.x block layer and io_uring tree(s)