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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
mtd: rawnand: gpmi: Add large oob bch setting support
The code change proposes a new way to set bch geometry for large oob
NAND (oobsize > 1KB). In this case, previous implementation can NOT
guarantee the bad block mark always locates in data chunk, so we need a
new way to do it. The general idea is,
1.Try all ECC strength from the maximum ecc that controller can support
to minimum value required by NAND chip, any ECC strength makes the
BBM locate in data chunk can be eligible.
2.If none of them works, using separate ECC for meta, which will add
one extra ecc with the same ECC strength as other data chunks. This
extra ECC can guarantee BBM located in data chunk, also we need to
check if oob can afford it.
Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220412025246.24269-6-han.xu@nxp.com
authored by
Han Xu
and committed by
Miquel Raynal
d9edc4bc
2fb038ea
+197
-5
+194
-5
drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+194
-5
drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
···
266
266
return true;
267
267
}
268
268
269
+
/* check if bbm locates in data chunk rather than ecc chunk */
270
+
static bool bbm_in_data_chunk(struct gpmi_nand_data *this,
271
+
unsigned int *chunk_num)
272
+
{
273
+
struct bch_geometry *geo = &this->bch_geometry;
274
+
struct nand_chip *chip = &this->nand;
275
+
struct mtd_info *mtd = nand_to_mtd(chip);
276
+
unsigned int i, j;
277
+
278
+
if (geo->ecc0_chunk_size != geo->eccn_chunk_size) {
279
+
dev_err(this->dev,
280
+
"The size of ecc0_chunk must equal to eccn_chunk\n");
281
+
return false;
282
+
}
283
+
284
+
i = (mtd->writesize * 8 - geo->metadata_size * 8) /
285
+
(geo->gf_len * geo->ecc_strength +
286
+
geo->eccn_chunk_size * 8);
287
+
288
+
j = (mtd->writesize * 8 - geo->metadata_size * 8) -
289
+
(geo->gf_len * geo->ecc_strength +
290
+
geo->eccn_chunk_size * 8) * i;
291
+
292
+
if (j < geo->eccn_chunk_size * 8) {
293
+
*chunk_num = i+1;
294
+
dev_dbg(this->dev, "Set ecc to %d and bbm in chunk %d\n",
295
+
geo->ecc_strength, *chunk_num);
296
+
return true;
297
+
}
298
+
299
+
return false;
300
+
}
301
+
269
302
/*
270
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* If we can get the ECC information from the nand chip, we do not
271
304
* need to calculate them ourselves.
···
448
415
return round_down(ecc_strength, 2);
449
416
}
450
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418
+
static int set_geometry_for_large_oob(struct gpmi_nand_data *this)
419
+
{
420
+
struct bch_geometry *geo = &this->bch_geometry;
421
+
struct nand_chip *chip = &this->nand;
422
+
struct mtd_info *mtd = nand_to_mtd(chip);
423
+
const struct nand_ecc_props *requirements =
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+
nanddev_get_ecc_requirements(&chip->base);
425
+
unsigned int block_mark_bit_offset;
426
+
unsigned int max_ecc;
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+
unsigned int bbm_chunk;
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+
unsigned int i;
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+
430
+
/* sanity check for the minimum ecc nand required */
431
+
if (!(requirements->strength > 0 &&
432
+
requirements->step_size > 0))
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+
return -EINVAL;
434
+
geo->ecc_strength = requirements->strength;
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+
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+
/* check if platform can support this nand */
437
+
if (!gpmi_check_ecc(this)) {
438
+
dev_err(this->dev,
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+
"unsupported NAND chip, minimum ecc required %d\n",
440
+
geo->ecc_strength);
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+
return -EINVAL;
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+
}
443
+
444
+
/* calculate the maximum ecc platform can support*/
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+
geo->metadata_size = 10;
446
+
geo->gf_len = 14;
447
+
geo->ecc0_chunk_size = 1024;
448
+
geo->eccn_chunk_size = 1024;
449
+
geo->ecc_chunk_count = mtd->writesize / geo->eccn_chunk_size;
450
+
max_ecc = min(get_ecc_strength(this),
451
+
this->devdata->bch_max_ecc_strength);
452
+
453
+
/*
454
+
* search a supported ecc strength that makes bbm
455
+
* located in data chunk
456
+
*/
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+
geo->ecc_strength = max_ecc;
458
+
while (!(geo->ecc_strength < requirements->strength)) {
459
+
if (bbm_in_data_chunk(this, &bbm_chunk))
460
+
goto geo_setting;
461
+
geo->ecc_strength -= 2;
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+
}
463
+
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+
/* if none of them works, keep using the minimum ecc */
465
+
/* nand required but changing ecc page layout */
466
+
geo->ecc_strength = requirements->strength;
467
+
/* add extra ecc for meta data */
468
+
geo->ecc0_chunk_size = 0;
469
+
geo->ecc_chunk_count = (mtd->writesize / geo->eccn_chunk_size) + 1;
470
+
geo->ecc_for_meta = 1;
471
+
/* check if oob can afford this extra ecc chunk */
472
+
if (mtd->oobsize * 8 < geo->metadata_size * 8 +
473
+
geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) {
474
+
dev_err(this->dev, "unsupported NAND chip with new layout\n");
475
+
return -EINVAL;
476
+
}
477
+
478
+
/* calculate in which chunk bbm located */
479
+
bbm_chunk = (mtd->writesize * 8 - geo->metadata_size * 8 -
480
+
geo->gf_len * geo->ecc_strength) /
481
+
(geo->gf_len * geo->ecc_strength +
482
+
geo->eccn_chunk_size * 8) + 1;
483
+
484
+
geo_setting:
485
+
486
+
geo->page_size = mtd->writesize + geo->metadata_size +
487
+
(geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
488
+
geo->payload_size = mtd->writesize;
489
+
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+
/*
491
+
* The auxiliary buffer contains the metadata and the ECC status. The
492
+
* metadata is padded to the nearest 32-bit boundary. The ECC status
493
+
* contains one byte for every ECC chunk, and is also padded to the
494
+
* nearest 32-bit boundary.
495
+
*/
496
+
geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4);
497
+
geo->auxiliary_size = ALIGN(geo->metadata_size, 4)
498
+
+ ALIGN(geo->ecc_chunk_count, 4);
499
+
500
+
if (!this->swap_block_mark)
501
+
return 0;
502
+
503
+
/* calculate the number of ecc chunk behind the bbm */
504
+
i = (mtd->writesize / geo->eccn_chunk_size) - bbm_chunk + 1;
505
+
506
+
block_mark_bit_offset = mtd->writesize * 8 -
507
+
(geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - i)
508
+
+ geo->metadata_size * 8);
509
+
510
+
geo->block_mark_byte_offset = block_mark_bit_offset / 8;
511
+
geo->block_mark_bit_offset = block_mark_bit_offset % 8;
512
+
513
+
dev_dbg(this->dev, "BCH Geometry :\n"
514
+
"GF length : %u\n"
515
+
"ECC Strength : %u\n"
516
+
"Page Size in Bytes : %u\n"
517
+
"Metadata Size in Bytes : %u\n"
518
+
"ECC0 Chunk Size in Bytes: %u\n"
519
+
"ECCn Chunk Size in Bytes: %u\n"
520
+
"ECC Chunk Count : %u\n"
521
+
"Payload Size in Bytes : %u\n"
522
+
"Auxiliary Size in Bytes: %u\n"
523
+
"Auxiliary Status Offset: %u\n"
524
+
"Block Mark Byte Offset : %u\n"
525
+
"Block Mark Bit Offset : %u\n"
526
+
"Block Mark in chunk : %u\n"
527
+
"Ecc for Meta data : %u\n",
528
+
geo->gf_len,
529
+
geo->ecc_strength,
530
+
geo->page_size,
531
+
geo->metadata_size,
532
+
geo->ecc0_chunk_size,
533
+
geo->eccn_chunk_size,
534
+
geo->ecc_chunk_count,
535
+
geo->payload_size,
536
+
geo->auxiliary_size,
537
+
geo->auxiliary_status_offset,
538
+
geo->block_mark_byte_offset,
539
+
geo->block_mark_bit_offset,
540
+
bbm_chunk,
541
+
geo->ecc_for_meta);
542
+
543
+
return 0;
544
+
}
545
+
451
546
static int legacy_set_geometry(struct gpmi_nand_data *this)
452
547
{
453
548
struct bch_geometry *geo = &this->bch_geometry;
···
707
546
!(requirements->strength > 0 && requirements->step_size > 0)) {
708
547
dev_dbg(this->dev, "use legacy bch geometry\n");
709
548
err = legacy_set_geometry(this);
549
+
if (!err)
550
+
return 0;
551
+
}
552
+
553
+
/* for large oob nand */
554
+
if (mtd->oobsize > 1024) {
555
+
dev_dbg(this->dev, "use large oob bch geometry\n");
556
+
err = set_geometry_for_large_oob(this);
710
557
if (!err)
711
558
return 0;
712
559
}
···
1602
1433
}
1603
1434
}
1604
1435
1436
+
/*
1437
+
* if there is an ECC dedicate for meta:
1438
+
* - need to add an extra ECC size when calculating col and page_size,
1439
+
* if the meta size is NOT zero.
1440
+
* - ecc0_chunk size need to set to the same size as other chunks,
1441
+
* if the meta size is zero.
1442
+
*/
1443
+
1605
1444
meta = geo->metadata_size;
1606
1445
if (first) {
1607
-
col = meta + (size + ecc_parity_size) * first;
1446
+
if (geo->ecc_for_meta)
1447
+
col = meta + ecc_parity_size
1448
+
+ (size + ecc_parity_size) * first;
1449
+
else
1450
+
col = meta + (size + ecc_parity_size) * first;
1451
+
1608
1452
meta = 0;
1609
1453
buf = buf + first * size;
1610
1454
}
1611
1455
1612
1456
ecc_parity_size = geo->gf_len * geo->ecc_strength / 8;
1613
-
1614
1457
n = last - first + 1;
1615
-
page_size = meta + (size + ecc_parity_size) * n;
1458
+
1459
+
if (geo->ecc_for_meta && meta)
1460
+
page_size = meta + ecc_parity_size
1461
+
+ (size + ecc_parity_size) * n;
1462
+
else
1463
+
page_size = meta + (size + ecc_parity_size) * n;
1464
+
1616
1465
ecc_strength = geo->ecc_strength >> 1;
1617
1466
1618
-
this->bch_flashlayout0 = BF_BCH_FLASH0LAYOUT0_NBLOCKS(n - 1) |
1467
+
this->bch_flashlayout0 = BF_BCH_FLASH0LAYOUT0_NBLOCKS(
1468
+
(geo->ecc_for_meta ? n : n - 1)) |
1619
1469
BF_BCH_FLASH0LAYOUT0_META_SIZE(meta) |
1620
1470
BF_BCH_FLASH0LAYOUT0_ECC0(ecc_strength, this) |
1621
1471
BF_BCH_FLASH0LAYOUT0_GF(geo->gf_len, this) |
1622
-
BF_BCH_FLASH0LAYOUT0_DATA0_SIZE(geo->eccn_chunk_size, this);
1472
+
BF_BCH_FLASH0LAYOUT0_DATA0_SIZE((geo->ecc_for_meta ?
1473
+
0 : geo->ecc0_chunk_size), this);
1623
1474
1624
1475
this->bch_flashlayout1 = BF_BCH_FLASH0LAYOUT1_PAGE_SIZE(page_size) |
1625
1476
BF_BCH_FLASH0LAYOUT1_ECCN(ecc_strength, this) |
+3
drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
+3
drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.h
···
42
42
* which the underlying physical block mark appears.
43
43
* @block_mark_bit_offset: The bit offset into the ECC-based page view at
44
44
* which the underlying physical block mark appears.
45
+
* @ecc_for_meta: The flag to indicate if there is a dedicate ecc
46
+
* for meta.
45
47
*/
46
48
struct bch_geometry {
47
49
unsigned int gf_len;
···
58
56
unsigned int auxiliary_status_offset;
59
57
unsigned int block_mark_byte_offset;
60
58
unsigned int block_mark_bit_offset;
59
+
unsigned int ecc_for_meta; /* ECC for meta data */
61
60
};
62
61
63
62
/**