1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Core registration and callback routines for MTD
   4 * drivers and users.
   5 *
   6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   7 * Copyright © 2006      Red Hat UK Limited 
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/kernel.h>
  12#include <linux/ptrace.h>
  13#include <linux/seq_file.h>
  14#include <linux/string.h>
  15#include <linux/timer.h>
  16#include <linux/major.h>
  17#include <linux/fs.h>
  18#include <linux/err.h>
  19#include <linux/ioctl.h>
  20#include <linux/init.h>
  21#include <linux/of.h>
  22#include <linux/proc_fs.h>
  23#include <linux/idr.h>
  24#include <linux/backing-dev.h>
  25#include <linux/gfp.h>
  26#include <linux/slab.h>
  27#include <linux/reboot.h>
  28#include <linux/leds.h>
  29#include <linux/debugfs.h>
  30#include <linux/nvmem-provider.h>
  31
  32#include <linux/mtd/mtd.h>
  33#include <linux/mtd/partitions.h>
  34
  35#include "mtdcore.h"
  36
  37struct backing_dev_info *mtd_bdi;
  38
  39#ifdef CONFIG_PM_SLEEP
  40
  41static int mtd_cls_suspend(struct device *dev)
  42{
  43	struct mtd_info *mtd = dev_get_drvdata(dev);
  44
  45	return mtd ? mtd_suspend(mtd) : 0;
  46}
  47
  48static int mtd_cls_resume(struct device *dev)
  49{
  50	struct mtd_info *mtd = dev_get_drvdata(dev);
  51
  52	if (mtd)
  53		mtd_resume(mtd);
  54	return 0;
  55}
  56
  57static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
  58#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
  59#else
  60#define MTD_CLS_PM_OPS NULL
  61#endif
  62
  63static struct class mtd_class = {
  64	.name = "mtd",
  65	.owner = THIS_MODULE,
  66	.pm = MTD_CLS_PM_OPS,
  67};
  68
  69static DEFINE_IDR(mtd_idr);
  70
  71/* These are exported solely for the purpose of mtd_blkdevs.c. You
  72   should not use them for _anything_ else */
  73DEFINE_MUTEX(mtd_table_mutex);
  74EXPORT_SYMBOL_GPL(mtd_table_mutex);
  75
  76struct mtd_info *__mtd_next_device(int i)
  77{
  78	return idr_get_next(&mtd_idr, &i);
  79}
  80EXPORT_SYMBOL_GPL(__mtd_next_device);
  81
  82static LIST_HEAD(mtd_notifiers);
  83
  84
  85#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
  86
  87/* REVISIT once MTD uses the driver model better, whoever allocates
  88 * the mtd_info will probably want to use the release() hook...
  89 */
  90static void mtd_release(struct device *dev)
  91{
  92	struct mtd_info *mtd = dev_get_drvdata(dev);
  93	dev_t index = MTD_DEVT(mtd->index);
  94
  95	/* remove /dev/mtdXro node */
  96	device_destroy(&mtd_class, index + 1);
  97}
  98
  99static ssize_t mtd_type_show(struct device *dev,
 100		struct device_attribute *attr, char *buf)
 101{
 102	struct mtd_info *mtd = dev_get_drvdata(dev);
 103	char *type;
 104
 105	switch (mtd->type) {
 106	case MTD_ABSENT:
 107		type = "absent";
 108		break;
 109	case MTD_RAM:
 110		type = "ram";
 111		break;
 112	case MTD_ROM:
 113		type = "rom";
 114		break;
 115	case MTD_NORFLASH:
 116		type = "nor";
 117		break;
 118	case MTD_NANDFLASH:
 119		type = "nand";
 120		break;
 121	case MTD_DATAFLASH:
 122		type = "dataflash";
 123		break;
 124	case MTD_UBIVOLUME:
 125		type = "ubi";
 126		break;
 127	case MTD_MLCNANDFLASH:
 128		type = "mlc-nand";
 129		break;
 130	default:
 131		type = "unknown";
 132	}
 133
 134	return snprintf(buf, PAGE_SIZE, "%s\n", type);
 135}
 136static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
 137
 138static ssize_t mtd_flags_show(struct device *dev,
 139		struct device_attribute *attr, char *buf)
 140{
 141	struct mtd_info *mtd = dev_get_drvdata(dev);
 142
 143	return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
 144}
 145static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
 146
 147static ssize_t mtd_size_show(struct device *dev,
 148		struct device_attribute *attr, char *buf)
 149{
 150	struct mtd_info *mtd = dev_get_drvdata(dev);
 151
 152	return snprintf(buf, PAGE_SIZE, "%llu\n",
 153		(unsigned long long)mtd->size);
 154}
 155static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
 156
 157static ssize_t mtd_erasesize_show(struct device *dev,
 158		struct device_attribute *attr, char *buf)
 159{
 160	struct mtd_info *mtd = dev_get_drvdata(dev);
 161
 162	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
 163}
 164static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
 165
 166static ssize_t mtd_writesize_show(struct device *dev,
 167		struct device_attribute *attr, char *buf)
 168{
 169	struct mtd_info *mtd = dev_get_drvdata(dev);
 170
 171	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
 172}
 173static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
 174
 175static ssize_t mtd_subpagesize_show(struct device *dev,
 176		struct device_attribute *attr, char *buf)
 177{
 178	struct mtd_info *mtd = dev_get_drvdata(dev);
 179	unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
 180
 181	return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
 182}
 183static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
 184
 185static ssize_t mtd_oobsize_show(struct device *dev,
 186		struct device_attribute *attr, char *buf)
 187{
 188	struct mtd_info *mtd = dev_get_drvdata(dev);
 189
 190	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
 191}
 192static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
 193
 194static ssize_t mtd_oobavail_show(struct device *dev,
 195				 struct device_attribute *attr, char *buf)
 196{
 197	struct mtd_info *mtd = dev_get_drvdata(dev);
 198
 199	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->oobavail);
 200}
 201static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
 202
 203static ssize_t mtd_numeraseregions_show(struct device *dev,
 204		struct device_attribute *attr, char *buf)
 205{
 206	struct mtd_info *mtd = dev_get_drvdata(dev);
 207
 208	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
 209}
 210static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
 211	NULL);
 212
 213static ssize_t mtd_name_show(struct device *dev,
 214		struct device_attribute *attr, char *buf)
 215{
 216	struct mtd_info *mtd = dev_get_drvdata(dev);
 217
 218	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
 219}
 220static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
 221
 222static ssize_t mtd_ecc_strength_show(struct device *dev,
 223				     struct device_attribute *attr, char *buf)
 224{
 225	struct mtd_info *mtd = dev_get_drvdata(dev);
 226
 227	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
 228}
 229static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
 230
 231static ssize_t mtd_bitflip_threshold_show(struct device *dev,
 232					  struct device_attribute *attr,
 233					  char *buf)
 234{
 235	struct mtd_info *mtd = dev_get_drvdata(dev);
 236
 237	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
 238}
 239
 240static ssize_t mtd_bitflip_threshold_store(struct device *dev,
 241					   struct device_attribute *attr,
 242					   const char *buf, size_t count)
 243{
 244	struct mtd_info *mtd = dev_get_drvdata(dev);
 245	unsigned int bitflip_threshold;
 246	int retval;
 247
 248	retval = kstrtouint(buf, 0, &bitflip_threshold);
 249	if (retval)
 250		return retval;
 251
 252	mtd->bitflip_threshold = bitflip_threshold;
 253	return count;
 254}
 255static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
 256		   mtd_bitflip_threshold_show,
 257		   mtd_bitflip_threshold_store);
 258
 259static ssize_t mtd_ecc_step_size_show(struct device *dev,
 260		struct device_attribute *attr, char *buf)
 261{
 262	struct mtd_info *mtd = dev_get_drvdata(dev);
 263
 264	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
 265
 266}
 267static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
 268
 269static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
 270		struct device_attribute *attr, char *buf)
 271{
 272	struct mtd_info *mtd = dev_get_drvdata(dev);
 273	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
 274
 275	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
 276}
 277static DEVICE_ATTR(corrected_bits, S_IRUGO,
 278		   mtd_ecc_stats_corrected_show, NULL);
 279
 280static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
 281		struct device_attribute *attr, char *buf)
 282{
 283	struct mtd_info *mtd = dev_get_drvdata(dev);
 284	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
 285
 286	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
 287}
 288static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
 289
 290static ssize_t mtd_badblocks_show(struct device *dev,
 291		struct device_attribute *attr, char *buf)
 292{
 293	struct mtd_info *mtd = dev_get_drvdata(dev);
 294	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
 295
 296	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
 297}
 298static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
 299
 300static ssize_t mtd_bbtblocks_show(struct device *dev,
 301		struct device_attribute *attr, char *buf)
 302{
 303	struct mtd_info *mtd = dev_get_drvdata(dev);
 304	struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
 305
 306	return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
 307}
 308static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
 309
 310static struct attribute *mtd_attrs[] = {
 311	&dev_attr_type.attr,
 312	&dev_attr_flags.attr,
 313	&dev_attr_size.attr,
 314	&dev_attr_erasesize.attr,
 315	&dev_attr_writesize.attr,
 316	&dev_attr_subpagesize.attr,
 317	&dev_attr_oobsize.attr,
 318	&dev_attr_oobavail.attr,
 319	&dev_attr_numeraseregions.attr,
 320	&dev_attr_name.attr,
 321	&dev_attr_ecc_strength.attr,
 322	&dev_attr_ecc_step_size.attr,
 323	&dev_attr_corrected_bits.attr,
 324	&dev_attr_ecc_failures.attr,
 325	&dev_attr_bad_blocks.attr,
 326	&dev_attr_bbt_blocks.attr,
 327	&dev_attr_bitflip_threshold.attr,
 328	NULL,
 329};
 330ATTRIBUTE_GROUPS(mtd);
 331
 332static const struct device_type mtd_devtype = {
 333	.name		= "mtd",
 334	.groups		= mtd_groups,
 335	.release	= mtd_release,
 336};
 337
 338static int mtd_partid_show(struct seq_file *s, void *p)
 339{
 340	struct mtd_info *mtd = s->private;
 341
 342	seq_printf(s, "%s\n", mtd->dbg.partid);
 343
 344	return 0;
 345}
 346
 347static int mtd_partid_debugfs_open(struct inode *inode, struct file *file)
 348{
 349	return single_open(file, mtd_partid_show, inode->i_private);
 350}
 351
 352static const struct file_operations mtd_partid_debug_fops = {
 353	.open           = mtd_partid_debugfs_open,
 354	.read           = seq_read,
 355	.llseek         = seq_lseek,
 356	.release        = single_release,
 357};
 358
 359static int mtd_partname_show(struct seq_file *s, void *p)
 360{
 361	struct mtd_info *mtd = s->private;
 362
 363	seq_printf(s, "%s\n", mtd->dbg.partname);
 364
 365	return 0;
 366}
 367
 368static int mtd_partname_debugfs_open(struct inode *inode, struct file *file)
 369{
 370	return single_open(file, mtd_partname_show, inode->i_private);
 371}
 372
 373static const struct file_operations mtd_partname_debug_fops = {
 374	.open           = mtd_partname_debugfs_open,
 375	.read           = seq_read,
 376	.llseek         = seq_lseek,
 377	.release        = single_release,
 378};
 379
 380static struct dentry *dfs_dir_mtd;
 381
 382static void mtd_debugfs_populate(struct mtd_info *mtd)
 383{
 384	struct device *dev = &mtd->dev;
 385	struct dentry *root;
 386
 387	if (IS_ERR_OR_NULL(dfs_dir_mtd))
 388		return;
 389
 390	root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
 
 
 
 
 
 391	mtd->dbg.dfs_dir = root;
 392
 393	if (mtd->dbg.partid)
 394		debugfs_create_file("partid", 0400, root, mtd,
 395				    &mtd_partid_debug_fops);
 396
 397	if (mtd->dbg.partname)
 398		debugfs_create_file("partname", 0400, root, mtd,
 399				    &mtd_partname_debug_fops);
 
 
 
 
 
 
 
 400}
 401
 402#ifndef CONFIG_MMU
 403unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
 404{
 405	switch (mtd->type) {
 406	case MTD_RAM:
 407		return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
 408			NOMMU_MAP_READ | NOMMU_MAP_WRITE;
 409	case MTD_ROM:
 410		return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
 411			NOMMU_MAP_READ;
 412	default:
 413		return NOMMU_MAP_COPY;
 414	}
 415}
 416EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
 417#endif
 418
 419static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
 420			       void *cmd)
 421{
 422	struct mtd_info *mtd;
 423
 424	mtd = container_of(n, struct mtd_info, reboot_notifier);
 425	mtd->_reboot(mtd);
 426
 427	return NOTIFY_DONE;
 428}
 429
 430/**
 431 * mtd_wunit_to_pairing_info - get pairing information of a wunit
 432 * @mtd: pointer to new MTD device info structure
 433 * @wunit: write unit we are interested in
 434 * @info: returned pairing information
 435 *
 436 * Retrieve pairing information associated to the wunit.
 437 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
 438 * paired together, and where programming a page may influence the page it is
 439 * paired with.
 440 * The notion of page is replaced by the term wunit (write-unit) to stay
 441 * consistent with the ->writesize field.
 442 *
 443 * The @wunit argument can be extracted from an absolute offset using
 444 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
 445 * to @wunit.
 446 *
 447 * From the pairing info the MTD user can find all the wunits paired with
 448 * @wunit using the following loop:
 449 *
 450 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
 451 *	info.pair = i;
 452 *	mtd_pairing_info_to_wunit(mtd, &info);
 453 *	...
 454 * }
 455 */
 456int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
 457			      struct mtd_pairing_info *info)
 458{
 459	struct mtd_info *master = mtd_get_master(mtd);
 460	int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
 461
 462	if (wunit < 0 || wunit >= npairs)
 463		return -EINVAL;
 464
 465	if (master->pairing && master->pairing->get_info)
 466		return master->pairing->get_info(master, wunit, info);
 467
 468	info->group = 0;
 469	info->pair = wunit;
 470
 471	return 0;
 472}
 473EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
 474
 475/**
 476 * mtd_pairing_info_to_wunit - get wunit from pairing information
 477 * @mtd: pointer to new MTD device info structure
 478 * @info: pairing information struct
 479 *
 480 * Returns a positive number representing the wunit associated to the info
 481 * struct, or a negative error code.
 482 *
 483 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
 484 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
 485 * doc).
 486 *
 487 * It can also be used to only program the first page of each pair (i.e.
 488 * page attached to group 0), which allows one to use an MLC NAND in
 489 * software-emulated SLC mode:
 490 *
 491 * info.group = 0;
 492 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
 493 * for (info.pair = 0; info.pair < npairs; info.pair++) {
 494 *	wunit = mtd_pairing_info_to_wunit(mtd, &info);
 495 *	mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
 496 *		  mtd->writesize, &retlen, buf + (i * mtd->writesize));
 497 * }
 498 */
 499int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
 500			      const struct mtd_pairing_info *info)
 501{
 502	struct mtd_info *master = mtd_get_master(mtd);
 503	int ngroups = mtd_pairing_groups(master);
 504	int npairs = mtd_wunit_per_eb(master) / ngroups;
 505
 506	if (!info || info->pair < 0 || info->pair >= npairs ||
 507	    info->group < 0 || info->group >= ngroups)
 508		return -EINVAL;
 509
 510	if (master->pairing && master->pairing->get_wunit)
 511		return mtd->pairing->get_wunit(master, info);
 512
 513	return info->pair;
 514}
 515EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
 516
 517/**
 518 * mtd_pairing_groups - get the number of pairing groups
 519 * @mtd: pointer to new MTD device info structure
 520 *
 521 * Returns the number of pairing groups.
 522 *
 523 * This number is usually equal to the number of bits exposed by a single
 524 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
 525 * to iterate over all pages of a given pair.
 526 */
 527int mtd_pairing_groups(struct mtd_info *mtd)
 528{
 529	struct mtd_info *master = mtd_get_master(mtd);
 530
 531	if (!master->pairing || !master->pairing->ngroups)
 532		return 1;
 533
 534	return master->pairing->ngroups;
 535}
 536EXPORT_SYMBOL_GPL(mtd_pairing_groups);
 537
 538static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
 539			      void *val, size_t bytes)
 540{
 541	struct mtd_info *mtd = priv;
 542	size_t retlen;
 543	int err;
 544
 545	err = mtd_read(mtd, offset, bytes, &retlen, val);
 546	if (err && err != -EUCLEAN)
 547		return err;
 548
 549	return retlen == bytes ? 0 : -EIO;
 550}
 551
 552static int mtd_nvmem_add(struct mtd_info *mtd)
 553{
 554	struct nvmem_config config = {};
 555
 556	config.id = -1;
 557	config.dev = &mtd->dev;
 558	config.name = dev_name(&mtd->dev);
 559	config.owner = THIS_MODULE;
 560	config.reg_read = mtd_nvmem_reg_read;
 561	config.size = mtd->size;
 562	config.word_size = 1;
 563	config.stride = 1;
 564	config.read_only = true;
 565	config.root_only = true;
 566	config.no_of_node = true;
 567	config.priv = mtd;
 568
 569	mtd->nvmem = nvmem_register(&config);
 570	if (IS_ERR(mtd->nvmem)) {
 571		/* Just ignore if there is no NVMEM support in the kernel */
 572		if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
 573			mtd->nvmem = NULL;
 574		} else {
 575			dev_err(&mtd->dev, "Failed to register NVMEM device\n");
 576			return PTR_ERR(mtd->nvmem);
 577		}
 578	}
 579
 580	return 0;
 581}
 582
 583/**
 584 *	add_mtd_device - register an MTD device
 585 *	@mtd: pointer to new MTD device info structure
 586 *
 587 *	Add a device to the list of MTD devices present in the system, and
 588 *	notify each currently active MTD 'user' of its arrival. Returns
 589 *	zero on success or non-zero on failure.
 590 */
 591
 592int add_mtd_device(struct mtd_info *mtd)
 593{
 594	struct mtd_info *master = mtd_get_master(mtd);
 595	struct mtd_notifier *not;
 596	int i, error;
 597
 598	/*
 599	 * May occur, for instance, on buggy drivers which call
 600	 * mtd_device_parse_register() multiple times on the same master MTD,
 601	 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
 602	 */
 603	if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
 604		return -EEXIST;
 605
 606	BUG_ON(mtd->writesize == 0);
 607
 608	/*
 609	 * MTD drivers should implement ->_{write,read}() or
 610	 * ->_{write,read}_oob(), but not both.
 611	 */
 612	if (WARN_ON((mtd->_write && mtd->_write_oob) ||
 613		    (mtd->_read && mtd->_read_oob)))
 614		return -EINVAL;
 615
 616	if (WARN_ON((!mtd->erasesize || !master->_erase) &&
 617		    !(mtd->flags & MTD_NO_ERASE)))
 618		return -EINVAL;
 619
 620	/*
 621	 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
 622	 * master is an MLC NAND and has a proper pairing scheme defined.
 623	 * We also reject masters that implement ->_writev() for now, because
 624	 * NAND controller drivers don't implement this hook, and adding the
 625	 * SLC -> MLC address/length conversion to this path is useless if we
 626	 * don't have a user.
 627	 */
 628	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
 629	    (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
 630	     !master->pairing || master->_writev))
 631		return -EINVAL;
 632
 633	mutex_lock(&mtd_table_mutex);
 634
 635	i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
 636	if (i < 0) {
 637		error = i;
 638		goto fail_locked;
 639	}
 640
 641	mtd->index = i;
 642	mtd->usecount = 0;
 643
 644	/* default value if not set by driver */
 645	if (mtd->bitflip_threshold == 0)
 646		mtd->bitflip_threshold = mtd->ecc_strength;
 647
 648	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
 649		int ngroups = mtd_pairing_groups(master);
 650
 651		mtd->erasesize /= ngroups;
 652		mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
 653			    mtd->erasesize;
 654	}
 655
 656	if (is_power_of_2(mtd->erasesize))
 657		mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
 658	else
 659		mtd->erasesize_shift = 0;
 660
 661	if (is_power_of_2(mtd->writesize))
 662		mtd->writesize_shift = ffs(mtd->writesize) - 1;
 663	else
 664		mtd->writesize_shift = 0;
 665
 666	mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
 667	mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
 668
 669	/* Some chips always power up locked. Unlock them now */
 670	if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
 671		error = mtd_unlock(mtd, 0, mtd->size);
 672		if (error && error != -EOPNOTSUPP)
 673			printk(KERN_WARNING
 674			       "%s: unlock failed, writes may not work\n",
 675			       mtd->name);
 676		/* Ignore unlock failures? */
 677		error = 0;
 678	}
 679
 680	/* Caller should have set dev.parent to match the
 681	 * physical device, if appropriate.
 682	 */
 683	mtd->dev.type = &mtd_devtype;
 684	mtd->dev.class = &mtd_class;
 685	mtd->dev.devt = MTD_DEVT(i);
 686	dev_set_name(&mtd->dev, "mtd%d", i);
 687	dev_set_drvdata(&mtd->dev, mtd);
 688	of_node_get(mtd_get_of_node(mtd));
 689	error = device_register(&mtd->dev);
 690	if (error)
 691		goto fail_added;
 692
 693	/* Add the nvmem provider */
 694	error = mtd_nvmem_add(mtd);
 695	if (error)
 696		goto fail_nvmem_add;
 697
 698	mtd_debugfs_populate(mtd);
 699
 700	device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
 701		      "mtd%dro", i);
 702
 703	pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
 704	/* No need to get a refcount on the module containing
 705	   the notifier, since we hold the mtd_table_mutex */
 706	list_for_each_entry(not, &mtd_notifiers, list)
 707		not->add(mtd);
 708
 709	mutex_unlock(&mtd_table_mutex);
 710	/* We _know_ we aren't being removed, because
 711	   our caller is still holding us here. So none
 712	   of this try_ nonsense, and no bitching about it
 713	   either. :) */
 714	__module_get(THIS_MODULE);
 715	return 0;
 716
 717fail_nvmem_add:
 718	device_unregister(&mtd->dev);
 719fail_added:
 720	of_node_put(mtd_get_of_node(mtd));
 721	idr_remove(&mtd_idr, i);
 722fail_locked:
 723	mutex_unlock(&mtd_table_mutex);
 724	return error;
 725}
 726
 727/**
 728 *	del_mtd_device - unregister an MTD device
 729 *	@mtd: pointer to MTD device info structure
 730 *
 731 *	Remove a device from the list of MTD devices present in the system,
 732 *	and notify each currently active MTD 'user' of its departure.
 733 *	Returns zero on success or 1 on failure, which currently will happen
 734 *	if the requested device does not appear to be present in the list.
 735 */
 736
 737int del_mtd_device(struct mtd_info *mtd)
 738{
 739	int ret;
 740	struct mtd_notifier *not;
 741
 742	mutex_lock(&mtd_table_mutex);
 743
 744	debugfs_remove_recursive(mtd->dbg.dfs_dir);
 745
 746	if (idr_find(&mtd_idr, mtd->index) != mtd) {
 747		ret = -ENODEV;
 748		goto out_error;
 749	}
 750
 751	/* No need to get a refcount on the module containing
 752		the notifier, since we hold the mtd_table_mutex */
 753	list_for_each_entry(not, &mtd_notifiers, list)
 754		not->remove(mtd);
 755
 756	if (mtd->usecount) {
 757		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
 758		       mtd->index, mtd->name, mtd->usecount);
 759		ret = -EBUSY;
 760	} else {
 761		/* Try to remove the NVMEM provider */
 762		if (mtd->nvmem)
 763			nvmem_unregister(mtd->nvmem);
 764
 765		device_unregister(&mtd->dev);
 766
 767		idr_remove(&mtd_idr, mtd->index);
 768		of_node_put(mtd_get_of_node(mtd));
 769
 770		module_put(THIS_MODULE);
 771		ret = 0;
 772	}
 773
 774out_error:
 775	mutex_unlock(&mtd_table_mutex);
 776	return ret;
 777}
 778
 779/*
 780 * Set a few defaults based on the parent devices, if not provided by the
 781 * driver
 782 */
 783static void mtd_set_dev_defaults(struct mtd_info *mtd)
 784{
 785	if (mtd->dev.parent) {
 786		if (!mtd->owner && mtd->dev.parent->driver)
 787			mtd->owner = mtd->dev.parent->driver->owner;
 788		if (!mtd->name)
 789			mtd->name = dev_name(mtd->dev.parent);
 790	} else {
 791		pr_debug("mtd device won't show a device symlink in sysfs\n");
 792	}
 793
 794	INIT_LIST_HEAD(&mtd->partitions);
 795	mutex_init(&mtd->master.partitions_lock);
 796}
 797
 798/**
 799 * mtd_device_parse_register - parse partitions and register an MTD device.
 800 *
 801 * @mtd: the MTD device to register
 802 * @types: the list of MTD partition probes to try, see
 803 *         'parse_mtd_partitions()' for more information
 804 * @parser_data: MTD partition parser-specific data
 805 * @parts: fallback partition information to register, if parsing fails;
 806 *         only valid if %nr_parts > %0
 807 * @nr_parts: the number of partitions in parts, if zero then the full
 808 *            MTD device is registered if no partition info is found
 809 *
 810 * This function aggregates MTD partitions parsing (done by
 811 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
 812 * basically follows the most common pattern found in many MTD drivers:
 813 *
 814 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
 815 *   registered first.
 816 * * Then It tries to probe partitions on MTD device @mtd using parsers
 817 *   specified in @types (if @types is %NULL, then the default list of parsers
 818 *   is used, see 'parse_mtd_partitions()' for more information). If none are
 819 *   found this functions tries to fallback to information specified in
 820 *   @parts/@nr_parts.
 821 * * If no partitions were found this function just registers the MTD device
 822 *   @mtd and exits.
 823 *
 824 * Returns zero in case of success and a negative error code in case of failure.
 825 */
 826int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
 827			      struct mtd_part_parser_data *parser_data,
 828			      const struct mtd_partition *parts,
 829			      int nr_parts)
 830{
 831	int ret;
 832
 833	mtd_set_dev_defaults(mtd);
 834
 835	if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
 836		ret = add_mtd_device(mtd);
 837		if (ret)
 838			return ret;
 839	}
 840
 841	/* Prefer parsed partitions over driver-provided fallback */
 842	ret = parse_mtd_partitions(mtd, types, parser_data);
 843	if (ret > 0)
 844		ret = 0;
 845	else if (nr_parts)
 846		ret = add_mtd_partitions(mtd, parts, nr_parts);
 847	else if (!device_is_registered(&mtd->dev))
 848		ret = add_mtd_device(mtd);
 849	else
 850		ret = 0;
 851
 852	if (ret)
 853		goto out;
 854
 855	/*
 856	 * FIXME: some drivers unfortunately call this function more than once.
 857	 * So we have to check if we've already assigned the reboot notifier.
 858	 *
 859	 * Generally, we can make multiple calls work for most cases, but it
 860	 * does cause problems with parse_mtd_partitions() above (e.g.,
 861	 * cmdlineparts will register partitions more than once).
 862	 */
 863	WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
 864		  "MTD already registered\n");
 865	if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
 866		mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
 867		register_reboot_notifier(&mtd->reboot_notifier);
 868	}
 869
 870out:
 871	if (ret && device_is_registered(&mtd->dev))
 872		del_mtd_device(mtd);
 873
 874	return ret;
 875}
 876EXPORT_SYMBOL_GPL(mtd_device_parse_register);
 877
 878/**
 879 * mtd_device_unregister - unregister an existing MTD device.
 880 *
 881 * @master: the MTD device to unregister.  This will unregister both the master
 882 *          and any partitions if registered.
 883 */
 884int mtd_device_unregister(struct mtd_info *master)
 885{
 886	int err;
 887
 888	if (master->_reboot)
 889		unregister_reboot_notifier(&master->reboot_notifier);
 890
 891	err = del_mtd_partitions(master);
 892	if (err)
 893		return err;
 894
 895	if (!device_is_registered(&master->dev))
 896		return 0;
 897
 898	return del_mtd_device(master);
 899}
 900EXPORT_SYMBOL_GPL(mtd_device_unregister);
 901
 902/**
 903 *	register_mtd_user - register a 'user' of MTD devices.
 904 *	@new: pointer to notifier info structure
 905 *
 906 *	Registers a pair of callbacks function to be called upon addition
 907 *	or removal of MTD devices. Causes the 'add' callback to be immediately
 908 *	invoked for each MTD device currently present in the system.
 909 */
 910void register_mtd_user (struct mtd_notifier *new)
 911{
 912	struct mtd_info *mtd;
 913
 914	mutex_lock(&mtd_table_mutex);
 915
 916	list_add(&new->list, &mtd_notifiers);
 917
 918	__module_get(THIS_MODULE);
 919
 920	mtd_for_each_device(mtd)
 921		new->add(mtd);
 922
 923	mutex_unlock(&mtd_table_mutex);
 924}
 925EXPORT_SYMBOL_GPL(register_mtd_user);
 926
 927/**
 928 *	unregister_mtd_user - unregister a 'user' of MTD devices.
 929 *	@old: pointer to notifier info structure
 930 *
 931 *	Removes a callback function pair from the list of 'users' to be
 932 *	notified upon addition or removal of MTD devices. Causes the
 933 *	'remove' callback to be immediately invoked for each MTD device
 934 *	currently present in the system.
 935 */
 936int unregister_mtd_user (struct mtd_notifier *old)
 937{
 938	struct mtd_info *mtd;
 939
 940	mutex_lock(&mtd_table_mutex);
 941
 942	module_put(THIS_MODULE);
 943
 944	mtd_for_each_device(mtd)
 945		old->remove(mtd);
 946
 947	list_del(&old->list);
 948	mutex_unlock(&mtd_table_mutex);
 949	return 0;
 950}
 951EXPORT_SYMBOL_GPL(unregister_mtd_user);
 952
 953/**
 954 *	get_mtd_device - obtain a validated handle for an MTD device
 955 *	@mtd: last known address of the required MTD device
 956 *	@num: internal device number of the required MTD device
 957 *
 958 *	Given a number and NULL address, return the num'th entry in the device
 959 *	table, if any.	Given an address and num == -1, search the device table
 960 *	for a device with that address and return if it's still present. Given
 961 *	both, return the num'th driver only if its address matches. Return
 962 *	error code if not.
 963 */
 964struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
 965{
 966	struct mtd_info *ret = NULL, *other;
 967	int err = -ENODEV;
 968
 969	mutex_lock(&mtd_table_mutex);
 970
 971	if (num == -1) {
 972		mtd_for_each_device(other) {
 973			if (other == mtd) {
 974				ret = mtd;
 975				break;
 976			}
 977		}
 978	} else if (num >= 0) {
 979		ret = idr_find(&mtd_idr, num);
 980		if (mtd && mtd != ret)
 981			ret = NULL;
 982	}
 983
 984	if (!ret) {
 985		ret = ERR_PTR(err);
 986		goto out;
 987	}
 988
 989	err = __get_mtd_device(ret);
 990	if (err)
 991		ret = ERR_PTR(err);
 992out:
 993	mutex_unlock(&mtd_table_mutex);
 994	return ret;
 995}
 996EXPORT_SYMBOL_GPL(get_mtd_device);
 997
 998
 999int __get_mtd_device(struct mtd_info *mtd)
1000{
1001	struct mtd_info *master = mtd_get_master(mtd);
1002	int err;
1003
1004	if (!try_module_get(master->owner))
1005		return -ENODEV;
1006
1007	if (master->_get_device) {
1008		err = master->_get_device(mtd);
1009
1010		if (err) {
1011			module_put(master->owner);
1012			return err;
1013		}
1014	}
1015
1016	while (mtd->parent) {
1017		mtd->usecount++;
1018		mtd = mtd->parent;
1019	}
1020
1021	return 0;
1022}
1023EXPORT_SYMBOL_GPL(__get_mtd_device);
1024
1025/**
1026 *	get_mtd_device_nm - obtain a validated handle for an MTD device by
1027 *	device name
1028 *	@name: MTD device name to open
1029 *
1030 * 	This function returns MTD device description structure in case of
1031 * 	success and an error code in case of failure.
1032 */
1033struct mtd_info *get_mtd_device_nm(const char *name)
1034{
1035	int err = -ENODEV;
1036	struct mtd_info *mtd = NULL, *other;
1037
1038	mutex_lock(&mtd_table_mutex);
1039
1040	mtd_for_each_device(other) {
1041		if (!strcmp(name, other->name)) {
1042			mtd = other;
1043			break;
1044		}
1045	}
1046
1047	if (!mtd)
1048		goto out_unlock;
1049
1050	err = __get_mtd_device(mtd);
1051	if (err)
1052		goto out_unlock;
1053
1054	mutex_unlock(&mtd_table_mutex);
1055	return mtd;
1056
1057out_unlock:
1058	mutex_unlock(&mtd_table_mutex);
1059	return ERR_PTR(err);
1060}
1061EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1062
1063void put_mtd_device(struct mtd_info *mtd)
1064{
1065	mutex_lock(&mtd_table_mutex);
1066	__put_mtd_device(mtd);
1067	mutex_unlock(&mtd_table_mutex);
1068
1069}
1070EXPORT_SYMBOL_GPL(put_mtd_device);
1071
1072void __put_mtd_device(struct mtd_info *mtd)
1073{
1074	struct mtd_info *master = mtd_get_master(mtd);
 
1075
1076	while (mtd->parent) {
1077		--mtd->usecount;
1078		BUG_ON(mtd->usecount < 0);
1079		mtd = mtd->parent;
1080	}
1081
1082	if (master->_put_device)
1083		master->_put_device(master);
1084
1085	module_put(master->owner);
1086}
1087EXPORT_SYMBOL_GPL(__put_mtd_device);
1088
1089/*
1090 * Erase is an synchronous operation. Device drivers are epected to return a
1091 * negative error code if the operation failed and update instr->fail_addr
1092 * to point the portion that was not properly erased.
1093 */
1094int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1095{
1096	struct mtd_info *master = mtd_get_master(mtd);
1097	u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1098	struct erase_info adjinstr;
1099	int ret;
1100
1101	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1102	adjinstr = *instr;
1103
1104	if (!mtd->erasesize || !master->_erase)
1105		return -ENOTSUPP;
1106
1107	if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1108		return -EINVAL;
1109	if (!(mtd->flags & MTD_WRITEABLE))
1110		return -EROFS;
1111
1112	if (!instr->len)
1113		return 0;
1114
1115	ledtrig_mtd_activity();
1116
1117	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1118		adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1119				master->erasesize;
1120		adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1121				master->erasesize) -
1122			       adjinstr.addr;
1123	}
1124
1125	adjinstr.addr += mst_ofs;
1126
1127	ret = master->_erase(master, &adjinstr);
1128
1129	if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1130		instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1131		if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1132			instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1133							 master);
1134			instr->fail_addr *= mtd->erasesize;
1135		}
1136	}
1137
1138	return ret;
1139}
1140EXPORT_SYMBOL_GPL(mtd_erase);
1141
1142/*
1143 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1144 */
1145int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1146	      void **virt, resource_size_t *phys)
1147{
1148	struct mtd_info *master = mtd_get_master(mtd);
1149
1150	*retlen = 0;
1151	*virt = NULL;
1152	if (phys)
1153		*phys = 0;
1154	if (!master->_point)
1155		return -EOPNOTSUPP;
1156	if (from < 0 || from >= mtd->size || len > mtd->size - from)
1157		return -EINVAL;
1158	if (!len)
1159		return 0;
1160
1161	from = mtd_get_master_ofs(mtd, from);
1162	return master->_point(master, from, len, retlen, virt, phys);
1163}
1164EXPORT_SYMBOL_GPL(mtd_point);
1165
1166/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1167int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1168{
1169	struct mtd_info *master = mtd_get_master(mtd);
1170
1171	if (!master->_unpoint)
1172		return -EOPNOTSUPP;
1173	if (from < 0 || from >= mtd->size || len > mtd->size - from)
1174		return -EINVAL;
1175	if (!len)
1176		return 0;
1177	return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1178}
1179EXPORT_SYMBOL_GPL(mtd_unpoint);
1180
1181/*
1182 * Allow NOMMU mmap() to directly map the device (if not NULL)
1183 * - return the address to which the offset maps
1184 * - return -ENOSYS to indicate refusal to do the mapping
1185 */
1186unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1187				    unsigned long offset, unsigned long flags)
1188{
1189	size_t retlen;
1190	void *virt;
1191	int ret;
1192
1193	ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1194	if (ret)
1195		return ret;
1196	if (retlen != len) {
1197		mtd_unpoint(mtd, offset, retlen);
1198		return -ENOSYS;
1199	}
1200	return (unsigned long)virt;
1201}
1202EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1203
1204static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1205				 const struct mtd_ecc_stats *old_stats)
1206{
1207	struct mtd_ecc_stats diff;
1208
1209	if (master == mtd)
1210		return;
1211
1212	diff = master->ecc_stats;
1213	diff.failed -= old_stats->failed;
1214	diff.corrected -= old_stats->corrected;
1215
1216	while (mtd->parent) {
1217		mtd->ecc_stats.failed += diff.failed;
1218		mtd->ecc_stats.corrected += diff.corrected;
1219		mtd = mtd->parent;
1220	}
1221}
1222
1223int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1224	     u_char *buf)
1225{
1226	struct mtd_oob_ops ops = {
1227		.len = len,
1228		.datbuf = buf,
1229	};
1230	int ret;
1231
1232	ret = mtd_read_oob(mtd, from, &ops);
1233	*retlen = ops.retlen;
1234
1235	return ret;
1236}
1237EXPORT_SYMBOL_GPL(mtd_read);
1238
1239int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1240	      const u_char *buf)
1241{
1242	struct mtd_oob_ops ops = {
1243		.len = len,
1244		.datbuf = (u8 *)buf,
1245	};
1246	int ret;
1247
1248	ret = mtd_write_oob(mtd, to, &ops);
1249	*retlen = ops.retlen;
1250
1251	return ret;
1252}
1253EXPORT_SYMBOL_GPL(mtd_write);
1254
1255/*
1256 * In blackbox flight recorder like scenarios we want to make successful writes
1257 * in interrupt context. panic_write() is only intended to be called when its
1258 * known the kernel is about to panic and we need the write to succeed. Since
1259 * the kernel is not going to be running for much longer, this function can
1260 * break locks and delay to ensure the write succeeds (but not sleep).
1261 */
1262int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1263		    const u_char *buf)
1264{
1265	struct mtd_info *master = mtd_get_master(mtd);
1266
1267	*retlen = 0;
1268	if (!master->_panic_write)
1269		return -EOPNOTSUPP;
1270	if (to < 0 || to >= mtd->size || len > mtd->size - to)
1271		return -EINVAL;
1272	if (!(mtd->flags & MTD_WRITEABLE))
1273		return -EROFS;
1274	if (!len)
1275		return 0;
1276	if (!master->oops_panic_write)
1277		master->oops_panic_write = true;
1278
1279	return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1280				    retlen, buf);
1281}
1282EXPORT_SYMBOL_GPL(mtd_panic_write);
1283
1284static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1285			     struct mtd_oob_ops *ops)
1286{
1287	/*
1288	 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1289	 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1290	 *  this case.
1291	 */
1292	if (!ops->datbuf)
1293		ops->len = 0;
1294
1295	if (!ops->oobbuf)
1296		ops->ooblen = 0;
1297
1298	if (offs < 0 || offs + ops->len > mtd->size)
1299		return -EINVAL;
1300
1301	if (ops->ooblen) {
1302		size_t maxooblen;
1303
1304		if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1305			return -EINVAL;
1306
1307		maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1308				      mtd_div_by_ws(offs, mtd)) *
1309			     mtd_oobavail(mtd, ops)) - ops->ooboffs;
1310		if (ops->ooblen > maxooblen)
1311			return -EINVAL;
1312	}
1313
1314	return 0;
1315}
1316
1317static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1318			    struct mtd_oob_ops *ops)
1319{
1320	struct mtd_info *master = mtd_get_master(mtd);
1321	int ret;
1322
1323	from = mtd_get_master_ofs(mtd, from);
1324	if (master->_read_oob)
1325		ret = master->_read_oob(master, from, ops);
1326	else
1327		ret = master->_read(master, from, ops->len, &ops->retlen,
1328				    ops->datbuf);
1329
1330	return ret;
1331}
1332
1333static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1334			     struct mtd_oob_ops *ops)
1335{
1336	struct mtd_info *master = mtd_get_master(mtd);
1337	int ret;
1338
1339	to = mtd_get_master_ofs(mtd, to);
1340	if (master->_write_oob)
1341		ret = master->_write_oob(master, to, ops);
1342	else
1343		ret = master->_write(master, to, ops->len, &ops->retlen,
1344				     ops->datbuf);
1345
1346	return ret;
1347}
1348
1349static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1350			       struct mtd_oob_ops *ops)
1351{
1352	struct mtd_info *master = mtd_get_master(mtd);
1353	int ngroups = mtd_pairing_groups(master);
1354	int npairs = mtd_wunit_per_eb(master) / ngroups;
1355	struct mtd_oob_ops adjops = *ops;
1356	unsigned int wunit, oobavail;
1357	struct mtd_pairing_info info;
1358	int max_bitflips = 0;
1359	u32 ebofs, pageofs;
1360	loff_t base, pos;
1361
1362	ebofs = mtd_mod_by_eb(start, mtd);
1363	base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1364	info.group = 0;
1365	info.pair = mtd_div_by_ws(ebofs, mtd);
1366	pageofs = mtd_mod_by_ws(ebofs, mtd);
1367	oobavail = mtd_oobavail(mtd, ops);
1368
1369	while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1370		int ret;
1371
1372		if (info.pair >= npairs) {
1373			info.pair = 0;
1374			base += master->erasesize;
1375		}
1376
1377		wunit = mtd_pairing_info_to_wunit(master, &info);
1378		pos = mtd_wunit_to_offset(mtd, base, wunit);
1379
1380		adjops.len = ops->len - ops->retlen;
1381		if (adjops.len > mtd->writesize - pageofs)
1382			adjops.len = mtd->writesize - pageofs;
1383
1384		adjops.ooblen = ops->ooblen - ops->oobretlen;
1385		if (adjops.ooblen > oobavail - adjops.ooboffs)
1386			adjops.ooblen = oobavail - adjops.ooboffs;
1387
1388		if (read) {
1389			ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1390			if (ret > 0)
1391				max_bitflips = max(max_bitflips, ret);
1392		} else {
1393			ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1394		}
1395
1396		if (ret < 0)
1397			return ret;
1398
1399		max_bitflips = max(max_bitflips, ret);
1400		ops->retlen += adjops.retlen;
1401		ops->oobretlen += adjops.oobretlen;
1402		adjops.datbuf += adjops.retlen;
1403		adjops.oobbuf += adjops.oobretlen;
1404		adjops.ooboffs = 0;
1405		pageofs = 0;
1406		info.pair++;
1407	}
1408
1409	return max_bitflips;
1410}
1411
1412int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1413{
1414	struct mtd_info *master = mtd_get_master(mtd);
1415	struct mtd_ecc_stats old_stats = master->ecc_stats;
1416	int ret_code;
1417
1418	ops->retlen = ops->oobretlen = 0;
1419
1420	ret_code = mtd_check_oob_ops(mtd, from, ops);
1421	if (ret_code)
1422		return ret_code;
1423
1424	ledtrig_mtd_activity();
1425
1426	/* Check the validity of a potential fallback on mtd->_read */
1427	if (!master->_read_oob && (!master->_read || ops->oobbuf))
1428		return -EOPNOTSUPP;
1429
1430	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1431		ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1432	else
1433		ret_code = mtd_read_oob_std(mtd, from, ops);
1434
1435	mtd_update_ecc_stats(mtd, master, &old_stats);
1436
1437	/*
1438	 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1439	 * similar to mtd->_read(), returning a non-negative integer
1440	 * representing max bitflips. In other cases, mtd->_read_oob() may
1441	 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1442	 */
1443	if (unlikely(ret_code < 0))
1444		return ret_code;
1445	if (mtd->ecc_strength == 0)
1446		return 0;	/* device lacks ecc */
1447	return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1448}
1449EXPORT_SYMBOL_GPL(mtd_read_oob);
1450
1451int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1452				struct mtd_oob_ops *ops)
1453{
1454	struct mtd_info *master = mtd_get_master(mtd);
1455	int ret;
1456
1457	ops->retlen = ops->oobretlen = 0;
1458
1459	if (!(mtd->flags & MTD_WRITEABLE))
1460		return -EROFS;
1461
1462	ret = mtd_check_oob_ops(mtd, to, ops);
1463	if (ret)
1464		return ret;
1465
1466	ledtrig_mtd_activity();
1467
1468	/* Check the validity of a potential fallback on mtd->_write */
1469	if (!master->_write_oob && (!master->_write || ops->oobbuf))
1470		return -EOPNOTSUPP;
1471
1472	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1473		return mtd_io_emulated_slc(mtd, to, false, ops);
1474
1475	return mtd_write_oob_std(mtd, to, ops);
 
1476}
1477EXPORT_SYMBOL_GPL(mtd_write_oob);
1478
1479/**
1480 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1481 * @mtd: MTD device structure
1482 * @section: ECC section. Depending on the layout you may have all the ECC
1483 *	     bytes stored in a single contiguous section, or one section
1484 *	     per ECC chunk (and sometime several sections for a single ECC
1485 *	     ECC chunk)
1486 * @oobecc: OOB region struct filled with the appropriate ECC position
1487 *	    information
1488 *
1489 * This function returns ECC section information in the OOB area. If you want
1490 * to get all the ECC bytes information, then you should call
1491 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1492 *
1493 * Returns zero on success, a negative error code otherwise.
1494 */
1495int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1496		      struct mtd_oob_region *oobecc)
1497{
1498	struct mtd_info *master = mtd_get_master(mtd);
1499
1500	memset(oobecc, 0, sizeof(*oobecc));
1501
1502	if (!master || section < 0)
1503		return -EINVAL;
1504
1505	if (!master->ooblayout || !master->ooblayout->ecc)
1506		return -ENOTSUPP;
1507
1508	return master->ooblayout->ecc(master, section, oobecc);
1509}
1510EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1511
1512/**
1513 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1514 *			section
1515 * @mtd: MTD device structure
1516 * @section: Free section you are interested in. Depending on the layout
1517 *	     you may have all the free bytes stored in a single contiguous
1518 *	     section, or one section per ECC chunk plus an extra section
1519 *	     for the remaining bytes (or other funky layout).
1520 * @oobfree: OOB region struct filled with the appropriate free position
1521 *	     information
1522 *
1523 * This function returns free bytes position in the OOB area. If you want
1524 * to get all the free bytes information, then you should call
1525 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1526 *
1527 * Returns zero on success, a negative error code otherwise.
1528 */
1529int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1530		       struct mtd_oob_region *oobfree)
1531{
1532	struct mtd_info *master = mtd_get_master(mtd);
1533
1534	memset(oobfree, 0, sizeof(*oobfree));
1535
1536	if (!master || section < 0)
1537		return -EINVAL;
1538
1539	if (!master->ooblayout || !master->ooblayout->free)
1540		return -ENOTSUPP;
1541
1542	return master->ooblayout->free(master, section, oobfree);
1543}
1544EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1545
1546/**
1547 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1548 * @mtd: mtd info structure
1549 * @byte: the byte we are searching for
1550 * @sectionp: pointer where the section id will be stored
1551 * @oobregion: used to retrieve the ECC position
1552 * @iter: iterator function. Should be either mtd_ooblayout_free or
1553 *	  mtd_ooblayout_ecc depending on the region type you're searching for
1554 *
1555 * This function returns the section id and oobregion information of a
1556 * specific byte. For example, say you want to know where the 4th ECC byte is
1557 * stored, you'll use:
1558 *
1559 * mtd_ooblayout_find_region(mtd, 3, &section, &oobregion, mtd_ooblayout_ecc);
1560 *
1561 * Returns zero on success, a negative error code otherwise.
1562 */
1563static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1564				int *sectionp, struct mtd_oob_region *oobregion,
1565				int (*iter)(struct mtd_info *,
1566					    int section,
1567					    struct mtd_oob_region *oobregion))
1568{
1569	int pos = 0, ret, section = 0;
1570
1571	memset(oobregion, 0, sizeof(*oobregion));
1572
1573	while (1) {
1574		ret = iter(mtd, section, oobregion);
1575		if (ret)
1576			return ret;
1577
1578		if (pos + oobregion->length > byte)
1579			break;
1580
1581		pos += oobregion->length;
1582		section++;
1583	}
1584
1585	/*
1586	 * Adjust region info to make it start at the beginning at the
1587	 * 'start' ECC byte.
1588	 */
1589	oobregion->offset += byte - pos;
1590	oobregion->length -= byte - pos;
1591	*sectionp = section;
1592
1593	return 0;
1594}
1595
1596/**
1597 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1598 *				  ECC byte
1599 * @mtd: mtd info structure
1600 * @eccbyte: the byte we are searching for
1601 * @sectionp: pointer where the section id will be stored
1602 * @oobregion: OOB region information
1603 *
1604 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1605 * byte.
1606 *
1607 * Returns zero on success, a negative error code otherwise.
1608 */
1609int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1610				 int *section,
1611				 struct mtd_oob_region *oobregion)
1612{
1613	return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1614					 mtd_ooblayout_ecc);
1615}
1616EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1617
1618/**
1619 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1620 * @mtd: mtd info structure
1621 * @buf: destination buffer to store OOB bytes
1622 * @oobbuf: OOB buffer
1623 * @start: first byte to retrieve
1624 * @nbytes: number of bytes to retrieve
1625 * @iter: section iterator
1626 *
1627 * Extract bytes attached to a specific category (ECC or free)
1628 * from the OOB buffer and copy them into buf.
1629 *
1630 * Returns zero on success, a negative error code otherwise.
1631 */
1632static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1633				const u8 *oobbuf, int start, int nbytes,
1634				int (*iter)(struct mtd_info *,
1635					    int section,
1636					    struct mtd_oob_region *oobregion))
1637{
1638	struct mtd_oob_region oobregion;
1639	int section, ret;
1640
1641	ret = mtd_ooblayout_find_region(mtd, start, &section,
1642					&oobregion, iter);
1643
1644	while (!ret) {
1645		int cnt;
1646
1647		cnt = min_t(int, nbytes, oobregion.length);
1648		memcpy(buf, oobbuf + oobregion.offset, cnt);
1649		buf += cnt;
1650		nbytes -= cnt;
1651
1652		if (!nbytes)
1653			break;
1654
1655		ret = iter(mtd, ++section, &oobregion);
1656	}
1657
1658	return ret;
1659}
1660
1661/**
1662 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1663 * @mtd: mtd info structure
1664 * @buf: source buffer to get OOB bytes from
1665 * @oobbuf: OOB buffer
1666 * @start: first OOB byte to set
1667 * @nbytes: number of OOB bytes to set
1668 * @iter: section iterator
1669 *
1670 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1671 * is selected by passing the appropriate iterator.
1672 *
1673 * Returns zero on success, a negative error code otherwise.
1674 */
1675static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1676				u8 *oobbuf, int start, int nbytes,
1677				int (*iter)(struct mtd_info *,
1678					    int section,
1679					    struct mtd_oob_region *oobregion))
1680{
1681	struct mtd_oob_region oobregion;
1682	int section, ret;
1683
1684	ret = mtd_ooblayout_find_region(mtd, start, &section,
1685					&oobregion, iter);
1686
1687	while (!ret) {
1688		int cnt;
1689
1690		cnt = min_t(int, nbytes, oobregion.length);
1691		memcpy(oobbuf + oobregion.offset, buf, cnt);
1692		buf += cnt;
1693		nbytes -= cnt;
1694
1695		if (!nbytes)
1696			break;
1697
1698		ret = iter(mtd, ++section, &oobregion);
1699	}
1700
1701	return ret;
1702}
1703
1704/**
1705 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1706 * @mtd: mtd info structure
1707 * @iter: category iterator
1708 *
1709 * Count the number of bytes in a given category.
1710 *
1711 * Returns a positive value on success, a negative error code otherwise.
1712 */
1713static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1714				int (*iter)(struct mtd_info *,
1715					    int section,
1716					    struct mtd_oob_region *oobregion))
1717{
1718	struct mtd_oob_region oobregion;
1719	int section = 0, ret, nbytes = 0;
1720
1721	while (1) {
1722		ret = iter(mtd, section++, &oobregion);
1723		if (ret) {
1724			if (ret == -ERANGE)
1725				ret = nbytes;
1726			break;
1727		}
1728
1729		nbytes += oobregion.length;
1730	}
1731
1732	return ret;
1733}
1734
1735/**
1736 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1737 * @mtd: mtd info structure
1738 * @eccbuf: destination buffer to store ECC bytes
1739 * @oobbuf: OOB buffer
1740 * @start: first ECC byte to retrieve
1741 * @nbytes: number of ECC bytes to retrieve
1742 *
1743 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1744 *
1745 * Returns zero on success, a negative error code otherwise.
1746 */
1747int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1748			       const u8 *oobbuf, int start, int nbytes)
1749{
1750	return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1751				       mtd_ooblayout_ecc);
1752}
1753EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1754
1755/**
1756 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1757 * @mtd: mtd info structure
1758 * @eccbuf: source buffer to get ECC bytes from
1759 * @oobbuf: OOB buffer
1760 * @start: first ECC byte to set
1761 * @nbytes: number of ECC bytes to set
1762 *
1763 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1764 *
1765 * Returns zero on success, a negative error code otherwise.
1766 */
1767int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1768			       u8 *oobbuf, int start, int nbytes)
1769{
1770	return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1771				       mtd_ooblayout_ecc);
1772}
1773EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1774
1775/**
1776 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1777 * @mtd: mtd info structure
1778 * @databuf: destination buffer to store ECC bytes
1779 * @oobbuf: OOB buffer
1780 * @start: first ECC byte to retrieve
1781 * @nbytes: number of ECC bytes to retrieve
1782 *
1783 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1784 *
1785 * Returns zero on success, a negative error code otherwise.
1786 */
1787int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1788				const u8 *oobbuf, int start, int nbytes)
1789{
1790	return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1791				       mtd_ooblayout_free);
1792}
1793EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1794
1795/**
1796 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1797 * @mtd: mtd info structure
1798 * @databuf: source buffer to get data bytes from
1799 * @oobbuf: OOB buffer
1800 * @start: first ECC byte to set
1801 * @nbytes: number of ECC bytes to set
1802 *
1803 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
1804 *
1805 * Returns zero on success, a negative error code otherwise.
1806 */
1807int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1808				u8 *oobbuf, int start, int nbytes)
1809{
1810	return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1811				       mtd_ooblayout_free);
1812}
1813EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1814
1815/**
1816 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1817 * @mtd: mtd info structure
1818 *
1819 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1820 *
1821 * Returns zero on success, a negative error code otherwise.
1822 */
1823int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1824{
1825	return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1826}
1827EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1828
1829/**
1830 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1831 * @mtd: mtd info structure
1832 *
1833 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1834 *
1835 * Returns zero on success, a negative error code otherwise.
1836 */
1837int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1838{
1839	return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1840}
1841EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1842
1843/*
1844 * Method to access the protection register area, present in some flash
1845 * devices. The user data is one time programmable but the factory data is read
1846 * only.
1847 */
1848int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1849			   struct otp_info *buf)
1850{
1851	struct mtd_info *master = mtd_get_master(mtd);
1852
1853	if (!master->_get_fact_prot_info)
1854		return -EOPNOTSUPP;
1855	if (!len)
1856		return 0;
1857	return master->_get_fact_prot_info(master, len, retlen, buf);
1858}
1859EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1860
1861int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1862			   size_t *retlen, u_char *buf)
1863{
1864	struct mtd_info *master = mtd_get_master(mtd);
1865
1866	*retlen = 0;
1867	if (!master->_read_fact_prot_reg)
1868		return -EOPNOTSUPP;
1869	if (!len)
1870		return 0;
1871	return master->_read_fact_prot_reg(master, from, len, retlen, buf);
1872}
1873EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1874
1875int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1876			   struct otp_info *buf)
1877{
1878	struct mtd_info *master = mtd_get_master(mtd);
1879
1880	if (!master->_get_user_prot_info)
1881		return -EOPNOTSUPP;
1882	if (!len)
1883		return 0;
1884	return master->_get_user_prot_info(master, len, retlen, buf);
1885}
1886EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1887
1888int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1889			   size_t *retlen, u_char *buf)
1890{
1891	struct mtd_info *master = mtd_get_master(mtd);
1892
1893	*retlen = 0;
1894	if (!master->_read_user_prot_reg)
1895		return -EOPNOTSUPP;
1896	if (!len)
1897		return 0;
1898	return master->_read_user_prot_reg(master, from, len, retlen, buf);
1899}
1900EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1901
1902int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1903			    size_t *retlen, u_char *buf)
1904{
1905	struct mtd_info *master = mtd_get_master(mtd);
1906	int ret;
1907
1908	*retlen = 0;
1909	if (!master->_write_user_prot_reg)
1910		return -EOPNOTSUPP;
1911	if (!len)
1912		return 0;
1913	ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
1914	if (ret)
1915		return ret;
1916
1917	/*
1918	 * If no data could be written at all, we are out of memory and
1919	 * must return -ENOSPC.
1920	 */
1921	return (*retlen) ? 0 : -ENOSPC;
1922}
1923EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1924
1925int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1926{
1927	struct mtd_info *master = mtd_get_master(mtd);
1928
1929	if (!master->_lock_user_prot_reg)
1930		return -EOPNOTSUPP;
1931	if (!len)
1932		return 0;
1933	return master->_lock_user_prot_reg(master, from, len);
1934}
1935EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1936
1937/* Chip-supported device locking */
1938int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1939{
1940	struct mtd_info *master = mtd_get_master(mtd);
1941
1942	if (!master->_lock)
1943		return -EOPNOTSUPP;
1944	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1945		return -EINVAL;
1946	if (!len)
1947		return 0;
1948
1949	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1950		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1951		len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1952	}
1953
1954	return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
1955}
1956EXPORT_SYMBOL_GPL(mtd_lock);
1957
1958int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1959{
1960	struct mtd_info *master = mtd_get_master(mtd);
1961
1962	if (!master->_unlock)
1963		return -EOPNOTSUPP;
1964	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1965		return -EINVAL;
1966	if (!len)
1967		return 0;
1968
1969	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1970		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1971		len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1972	}
1973
1974	return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
1975}
1976EXPORT_SYMBOL_GPL(mtd_unlock);
1977
1978int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1979{
1980	struct mtd_info *master = mtd_get_master(mtd);
1981
1982	if (!master->_is_locked)
1983		return -EOPNOTSUPP;
1984	if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
1985		return -EINVAL;
1986	if (!len)
1987		return 0;
1988
1989	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1990		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
1991		len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
1992	}
1993
1994	return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
1995}
1996EXPORT_SYMBOL_GPL(mtd_is_locked);
1997
1998int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
1999{
2000	struct mtd_info *master = mtd_get_master(mtd);
2001
2002	if (ofs < 0 || ofs >= mtd->size)
2003		return -EINVAL;
2004	if (!master->_block_isreserved)
2005		return 0;
2006
2007	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2008		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2009
2010	return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2011}
2012EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2013
2014int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2015{
2016	struct mtd_info *master = mtd_get_master(mtd);
2017
2018	if (ofs < 0 || ofs >= mtd->size)
2019		return -EINVAL;
2020	if (!master->_block_isbad)
2021		return 0;
2022
2023	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2024		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2025
2026	return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2027}
2028EXPORT_SYMBOL_GPL(mtd_block_isbad);
2029
2030int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2031{
2032	struct mtd_info *master = mtd_get_master(mtd);
2033	int ret;
2034
2035	if (!master->_block_markbad)
2036		return -EOPNOTSUPP;
2037	if (ofs < 0 || ofs >= mtd->size)
2038		return -EINVAL;
2039	if (!(mtd->flags & MTD_WRITEABLE))
2040		return -EROFS;
2041
2042	if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2043		ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2044
2045	ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2046	if (ret)
2047		return ret;
2048
2049	while (mtd->parent) {
2050		mtd->ecc_stats.badblocks++;
2051		mtd = mtd->parent;
2052	}
2053
2054	return 0;
2055}
2056EXPORT_SYMBOL_GPL(mtd_block_markbad);
2057
2058/*
2059 * default_mtd_writev - the default writev method
2060 * @mtd: mtd device description object pointer
2061 * @vecs: the vectors to write
2062 * @count: count of vectors in @vecs
2063 * @to: the MTD device offset to write to
2064 * @retlen: on exit contains the count of bytes written to the MTD device.
2065 *
2066 * This function returns zero in case of success and a negative error code in
2067 * case of failure.
2068 */
2069static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2070			      unsigned long count, loff_t to, size_t *retlen)
2071{
2072	unsigned long i;
2073	size_t totlen = 0, thislen;
2074	int ret = 0;
2075
2076	for (i = 0; i < count; i++) {
2077		if (!vecs[i].iov_len)
2078			continue;
2079		ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2080				vecs[i].iov_base);
2081		totlen += thislen;
2082		if (ret || thislen != vecs[i].iov_len)
2083			break;
2084		to += vecs[i].iov_len;
2085	}
2086	*retlen = totlen;
2087	return ret;
2088}
2089
2090/*
2091 * mtd_writev - the vector-based MTD write method
2092 * @mtd: mtd device description object pointer
2093 * @vecs: the vectors to write
2094 * @count: count of vectors in @vecs
2095 * @to: the MTD device offset to write to
2096 * @retlen: on exit contains the count of bytes written to the MTD device.
2097 *
2098 * This function returns zero in case of success and a negative error code in
2099 * case of failure.
2100 */
2101int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2102	       unsigned long count, loff_t to, size_t *retlen)
2103{
2104	struct mtd_info *master = mtd_get_master(mtd);
2105
2106	*retlen = 0;
2107	if (!(mtd->flags & MTD_WRITEABLE))
2108		return -EROFS;
2109
2110	if (!master->_writev)
2111		return default_mtd_writev(mtd, vecs, count, to, retlen);
2112
2113	return master->_writev(master, vecs, count,
2114			       mtd_get_master_ofs(mtd, to), retlen);
2115}
2116EXPORT_SYMBOL_GPL(mtd_writev);
2117
2118/**
2119 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2120 * @mtd: mtd device description object pointer
2121 * @size: a pointer to the ideal or maximum size of the allocation, points
2122 *        to the actual allocation size on success.
2123 *
2124 * This routine attempts to allocate a contiguous kernel buffer up to
2125 * the specified size, backing off the size of the request exponentially
2126 * until the request succeeds or until the allocation size falls below
2127 * the system page size. This attempts to make sure it does not adversely
2128 * impact system performance, so when allocating more than one page, we
2129 * ask the memory allocator to avoid re-trying, swapping, writing back
2130 * or performing I/O.
2131 *
2132 * Note, this function also makes sure that the allocated buffer is aligned to
2133 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2134 *
2135 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2136 * to handle smaller (i.e. degraded) buffer allocations under low- or
2137 * fragmented-memory situations where such reduced allocations, from a
2138 * requested ideal, are allowed.
2139 *
2140 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2141 */
2142void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2143{
2144	gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2145	size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2146	void *kbuf;
2147
2148	*size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2149
2150	while (*size > min_alloc) {
2151		kbuf = kmalloc(*size, flags);
2152		if (kbuf)
2153			return kbuf;
2154
2155		*size >>= 1;
2156		*size = ALIGN(*size, mtd->writesize);
2157	}
2158
2159	/*
2160	 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2161	 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2162	 */
2163	return kmalloc(*size, GFP_KERNEL);
2164}
2165EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2166
2167#ifdef CONFIG_PROC_FS
2168
2169/*====================================================================*/
2170/* Support for /proc/mtd */
2171
2172static int mtd_proc_show(struct seq_file *m, void *v)
2173{
2174	struct mtd_info *mtd;
2175
2176	seq_puts(m, "dev:    size   erasesize  name\n");
2177	mutex_lock(&mtd_table_mutex);
2178	mtd_for_each_device(mtd) {
2179		seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2180			   mtd->index, (unsigned long long)mtd->size,
2181			   mtd->erasesize, mtd->name);
2182	}
2183	mutex_unlock(&mtd_table_mutex);
2184	return 0;
2185}
2186#endif /* CONFIG_PROC_FS */
2187
2188/*====================================================================*/
2189/* Init code */
2190
2191static struct backing_dev_info * __init mtd_bdi_init(char *name)
2192{
2193	struct backing_dev_info *bdi;
2194	int ret;
2195
2196	bdi = bdi_alloc(NUMA_NO_NODE);
2197	if (!bdi)
2198		return ERR_PTR(-ENOMEM);
2199
 
2200	/*
2201	 * We put '-0' suffix to the name to get the same name format as we
2202	 * used to get. Since this is called only once, we get a unique name. 
2203	 */
2204	ret = bdi_register(bdi, "%.28s-0", name);
2205	if (ret)
2206		bdi_put(bdi);
2207
2208	return ret ? ERR_PTR(ret) : bdi;
2209}
2210
2211static struct proc_dir_entry *proc_mtd;
2212
2213static int __init init_mtd(void)
2214{
2215	int ret;
2216
2217	ret = class_register(&mtd_class);
2218	if (ret)
2219		goto err_reg;
2220
2221	mtd_bdi = mtd_bdi_init("mtd");
2222	if (IS_ERR(mtd_bdi)) {
2223		ret = PTR_ERR(mtd_bdi);
2224		goto err_bdi;
2225	}
2226
2227	proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2228
2229	ret = init_mtdchar();
2230	if (ret)
2231		goto out_procfs;
2232
2233	dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2234
2235	return 0;
2236
2237out_procfs:
2238	if (proc_mtd)
2239		remove_proc_entry("mtd", NULL);
2240	bdi_put(mtd_bdi);
2241err_bdi:
2242	class_unregister(&mtd_class);
2243err_reg:
2244	pr_err("Error registering mtd class or bdi: %d\n", ret);
2245	return ret;
2246}
2247
2248static void __exit cleanup_mtd(void)
2249{
2250	debugfs_remove_recursive(dfs_dir_mtd);
2251	cleanup_mtdchar();
2252	if (proc_mtd)
2253		remove_proc_entry("mtd", NULL);
2254	class_unregister(&mtd_class);
2255	bdi_put(mtd_bdi);
2256	idr_destroy(&mtd_idr);
2257}
2258
2259module_init(init_mtd);
2260module_exit(cleanup_mtd);
2261
2262MODULE_LICENSE("GPL");
2263MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2264MODULE_DESCRIPTION("Core MTD registration and access routines");