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v5.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Simple MTD partitioning layer
   4 *
   5 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
   6 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
   7 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/types.h>
  12#include <linux/kernel.h>
  13#include <linux/slab.h>
  14#include <linux/list.h>
  15#include <linux/kmod.h>
  16#include <linux/mtd/mtd.h>
  17#include <linux/mtd/partitions.h>
  18#include <linux/err.h>
  19#include <linux/of.h>
 
  20
  21#include "mtdcore.h"
  22
  23/* Our partition linked list */
  24static LIST_HEAD(mtd_partitions);
  25static DEFINE_MUTEX(mtd_partitions_mutex);
  26
  27/**
  28 * struct mtd_part - our partition node structure
  29 *
  30 * @mtd: struct holding partition details
  31 * @parent: parent mtd - flash device or another partition
  32 * @offset: partition offset relative to the *flash device*
  33 */
  34struct mtd_part {
  35	struct mtd_info mtd;
  36	struct mtd_info *parent;
  37	uint64_t offset;
  38	struct list_head list;
  39};
  40
  41/*
  42 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  43 * the pointer to that structure.
  44 */
  45static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
  46{
  47	return container_of(mtd, struct mtd_part, mtd);
  48}
  49
  50static u64 part_absolute_offset(struct mtd_info *mtd)
  51{
  52	struct mtd_part *part = mtd_to_part(mtd);
  53
  54	if (!mtd_is_partition(mtd))
  55		return 0;
  56
  57	return part_absolute_offset(part->parent) + part->offset;
  58}
  59
  60/*
  61 * MTD methods which simply translate the effective address and pass through
  62 * to the _real_ device.
  63 */
  64
  65static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  66		size_t *retlen, u_char *buf)
  67{
  68	struct mtd_part *part = mtd_to_part(mtd);
  69	struct mtd_ecc_stats stats;
  70	int res;
  71
  72	stats = part->parent->ecc_stats;
  73	res = part->parent->_read(part->parent, from + part->offset, len,
  74				  retlen, buf);
  75	if (unlikely(mtd_is_eccerr(res)))
  76		mtd->ecc_stats.failed +=
  77			part->parent->ecc_stats.failed - stats.failed;
  78	else
  79		mtd->ecc_stats.corrected +=
  80			part->parent->ecc_stats.corrected - stats.corrected;
  81	return res;
  82}
  83
  84static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  85		size_t *retlen, void **virt, resource_size_t *phys)
  86{
  87	struct mtd_part *part = mtd_to_part(mtd);
  88
  89	return part->parent->_point(part->parent, from + part->offset, len,
  90				    retlen, virt, phys);
  91}
  92
  93static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  94{
  95	struct mtd_part *part = mtd_to_part(mtd);
  96
  97	return part->parent->_unpoint(part->parent, from + part->offset, len);
  98}
  99
 100static int part_read_oob(struct mtd_info *mtd, loff_t from,
 101		struct mtd_oob_ops *ops)
 102{
 103	struct mtd_part *part = mtd_to_part(mtd);
 104	struct mtd_ecc_stats stats;
 105	int res;
 106
 107	stats = part->parent->ecc_stats;
 108	res = part->parent->_read_oob(part->parent, from + part->offset, ops);
 109	if (unlikely(mtd_is_eccerr(res)))
 110		mtd->ecc_stats.failed +=
 111			part->parent->ecc_stats.failed - stats.failed;
 112	else
 113		mtd->ecc_stats.corrected +=
 114			part->parent->ecc_stats.corrected - stats.corrected;
 115	return res;
 116}
 117
 118static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 119		size_t len, size_t *retlen, u_char *buf)
 120{
 121	struct mtd_part *part = mtd_to_part(mtd);
 122	return part->parent->_read_user_prot_reg(part->parent, from, len,
 123						 retlen, buf);
 124}
 125
 126static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
 127				   size_t *retlen, struct otp_info *buf)
 128{
 129	struct mtd_part *part = mtd_to_part(mtd);
 130	return part->parent->_get_user_prot_info(part->parent, len, retlen,
 131						 buf);
 132}
 133
 134static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 135		size_t len, size_t *retlen, u_char *buf)
 136{
 137	struct mtd_part *part = mtd_to_part(mtd);
 138	return part->parent->_read_fact_prot_reg(part->parent, from, len,
 139						 retlen, buf);
 140}
 141
 142static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
 143				   size_t *retlen, struct otp_info *buf)
 144{
 145	struct mtd_part *part = mtd_to_part(mtd);
 146	return part->parent->_get_fact_prot_info(part->parent, len, retlen,
 147						 buf);
 148}
 149
 150static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 151		size_t *retlen, const u_char *buf)
 152{
 153	struct mtd_part *part = mtd_to_part(mtd);
 154	return part->parent->_write(part->parent, to + part->offset, len,
 155				    retlen, buf);
 156}
 157
 158static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 159		size_t *retlen, const u_char *buf)
 160{
 161	struct mtd_part *part = mtd_to_part(mtd);
 162	return part->parent->_panic_write(part->parent, to + part->offset, len,
 163					  retlen, buf);
 164}
 165
 166static int part_write_oob(struct mtd_info *mtd, loff_t to,
 167		struct mtd_oob_ops *ops)
 168{
 169	struct mtd_part *part = mtd_to_part(mtd);
 170
 171	return part->parent->_write_oob(part->parent, to + part->offset, ops);
 172}
 173
 174static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 175		size_t len, size_t *retlen, u_char *buf)
 176{
 177	struct mtd_part *part = mtd_to_part(mtd);
 178	return part->parent->_write_user_prot_reg(part->parent, from, len,
 179						  retlen, buf);
 180}
 181
 182static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 183		size_t len)
 184{
 185	struct mtd_part *part = mtd_to_part(mtd);
 186	return part->parent->_lock_user_prot_reg(part->parent, from, len);
 187}
 188
 189static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 190		unsigned long count, loff_t to, size_t *retlen)
 191{
 192	struct mtd_part *part = mtd_to_part(mtd);
 193	return part->parent->_writev(part->parent, vecs, count,
 194				     to + part->offset, retlen);
 195}
 196
 197static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 198{
 199	struct mtd_part *part = mtd_to_part(mtd);
 200	int ret;
 201
 202	instr->addr += part->offset;
 203	ret = part->parent->_erase(part->parent, instr);
 204	if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 205		instr->fail_addr -= part->offset;
 206	instr->addr -= part->offset;
 207
 208	return ret;
 209}
 210
 211static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 212{
 213	struct mtd_part *part = mtd_to_part(mtd);
 214	return part->parent->_lock(part->parent, ofs + part->offset, len);
 215}
 216
 217static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 218{
 219	struct mtd_part *part = mtd_to_part(mtd);
 220	return part->parent->_unlock(part->parent, ofs + part->offset, len);
 221}
 222
 223static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 224{
 225	struct mtd_part *part = mtd_to_part(mtd);
 226	return part->parent->_is_locked(part->parent, ofs + part->offset, len);
 227}
 228
 229static void part_sync(struct mtd_info *mtd)
 230{
 231	struct mtd_part *part = mtd_to_part(mtd);
 232	part->parent->_sync(part->parent);
 233}
 234
 235static int part_suspend(struct mtd_info *mtd)
 
 
 236{
 237	struct mtd_part *part = mtd_to_part(mtd);
 238	return part->parent->_suspend(part->parent);
 239}
 240
 241static void part_resume(struct mtd_info *mtd)
 242{
 243	struct mtd_part *part = mtd_to_part(mtd);
 244	part->parent->_resume(part->parent);
 245}
 246
 247static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 248{
 249	struct mtd_part *part = mtd_to_part(mtd);
 250	ofs += part->offset;
 251	return part->parent->_block_isreserved(part->parent, ofs);
 252}
 253
 254static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 255{
 256	struct mtd_part *part = mtd_to_part(mtd);
 257	ofs += part->offset;
 258	return part->parent->_block_isbad(part->parent, ofs);
 259}
 260
 261static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 262{
 263	struct mtd_part *part = mtd_to_part(mtd);
 264	int res;
 265
 266	ofs += part->offset;
 267	res = part->parent->_block_markbad(part->parent, ofs);
 268	if (!res)
 269		mtd->ecc_stats.badblocks++;
 270	return res;
 271}
 272
 273static int part_get_device(struct mtd_info *mtd)
 274{
 275	struct mtd_part *part = mtd_to_part(mtd);
 276	return part->parent->_get_device(part->parent);
 277}
 278
 279static void part_put_device(struct mtd_info *mtd)
 280{
 281	struct mtd_part *part = mtd_to_part(mtd);
 282	part->parent->_put_device(part->parent);
 283}
 284
 285static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
 286			      struct mtd_oob_region *oobregion)
 287{
 288	struct mtd_part *part = mtd_to_part(mtd);
 289
 290	return mtd_ooblayout_ecc(part->parent, section, oobregion);
 291}
 292
 293static int part_ooblayout_free(struct mtd_info *mtd, int section,
 294			       struct mtd_oob_region *oobregion)
 295{
 296	struct mtd_part *part = mtd_to_part(mtd);
 297
 298	return mtd_ooblayout_free(part->parent, section, oobregion);
 299}
 300
 301static const struct mtd_ooblayout_ops part_ooblayout_ops = {
 302	.ecc = part_ooblayout_ecc,
 303	.free = part_ooblayout_free,
 304};
 305
 306static int part_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
 307{
 308	struct mtd_part *part = mtd_to_part(mtd);
 309
 310	return part->parent->_max_bad_blocks(part->parent,
 311					     ofs + part->offset, len);
 312}
 313
 314static inline void free_partition(struct mtd_part *p)
 315{
 316	kfree(p->mtd.name);
 317	kfree(p);
 318}
 319
 320static struct mtd_part *allocate_partition(struct mtd_info *parent,
 321			const struct mtd_partition *part, int partno,
 322			uint64_t cur_offset)
 323{
 324	int wr_alignment = (parent->flags & MTD_NO_ERASE) ? parent->writesize :
 325							    parent->erasesize;
 326	struct mtd_part *slave;
 327	u32 remainder;
 328	char *name;
 329	u64 tmp;
 330
 331	/* allocate the partition structure */
 332	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 333	name = kstrdup(part->name, GFP_KERNEL);
 334	if (!name || !slave) {
 335		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 336		       parent->name);
 337		kfree(name);
 338		kfree(slave);
 339		return ERR_PTR(-ENOMEM);
 340	}
 341
 342	/* set up the MTD object for this partition */
 343	slave->mtd.type = parent->type;
 344	slave->mtd.flags = parent->orig_flags & ~part->mask_flags;
 345	slave->mtd.orig_flags = slave->mtd.flags;
 346	slave->mtd.size = part->size;
 347	slave->mtd.writesize = parent->writesize;
 348	slave->mtd.writebufsize = parent->writebufsize;
 349	slave->mtd.oobsize = parent->oobsize;
 350	slave->mtd.oobavail = parent->oobavail;
 351	slave->mtd.subpage_sft = parent->subpage_sft;
 352	slave->mtd.pairing = parent->pairing;
 353
 354	slave->mtd.name = name;
 355	slave->mtd.owner = parent->owner;
 356
 357	/* NOTE: Historically, we didn't arrange MTDs as a tree out of
 358	 * concern for showing the same data in multiple partitions.
 359	 * However, it is very useful to have the master node present,
 360	 * so the MTD_PARTITIONED_MASTER option allows that. The master
 361	 * will have device nodes etc only if this is set, so make the
 362	 * parent conditional on that option. Note, this is a way to
 363	 * distinguish between the master and the partition in sysfs.
 364	 */
 365	slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
 366				&parent->dev :
 367				parent->dev.parent;
 368	slave->mtd.dev.of_node = part->of_node;
 369
 370	if (parent->_read)
 371		slave->mtd._read = part_read;
 372	if (parent->_write)
 373		slave->mtd._write = part_write;
 374
 375	if (parent->_panic_write)
 376		slave->mtd._panic_write = part_panic_write;
 377
 378	if (parent->_point && parent->_unpoint) {
 379		slave->mtd._point = part_point;
 380		slave->mtd._unpoint = part_unpoint;
 381	}
 382
 383	if (parent->_read_oob)
 384		slave->mtd._read_oob = part_read_oob;
 385	if (parent->_write_oob)
 386		slave->mtd._write_oob = part_write_oob;
 387	if (parent->_read_user_prot_reg)
 388		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 389	if (parent->_read_fact_prot_reg)
 390		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 391	if (parent->_write_user_prot_reg)
 392		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 393	if (parent->_lock_user_prot_reg)
 394		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 395	if (parent->_get_user_prot_info)
 396		slave->mtd._get_user_prot_info = part_get_user_prot_info;
 397	if (parent->_get_fact_prot_info)
 398		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 399	if (parent->_sync)
 400		slave->mtd._sync = part_sync;
 401	if (!partno && !parent->dev.class && parent->_suspend &&
 402	    parent->_resume) {
 403		slave->mtd._suspend = part_suspend;
 404		slave->mtd._resume = part_resume;
 405	}
 406	if (parent->_writev)
 407		slave->mtd._writev = part_writev;
 408	if (parent->_lock)
 409		slave->mtd._lock = part_lock;
 410	if (parent->_unlock)
 411		slave->mtd._unlock = part_unlock;
 412	if (parent->_is_locked)
 413		slave->mtd._is_locked = part_is_locked;
 414	if (parent->_block_isreserved)
 415		slave->mtd._block_isreserved = part_block_isreserved;
 416	if (parent->_block_isbad)
 417		slave->mtd._block_isbad = part_block_isbad;
 418	if (parent->_block_markbad)
 419		slave->mtd._block_markbad = part_block_markbad;
 420	if (parent->_max_bad_blocks)
 421		slave->mtd._max_bad_blocks = part_max_bad_blocks;
 422
 423	if (parent->_get_device)
 424		slave->mtd._get_device = part_get_device;
 425	if (parent->_put_device)
 426		slave->mtd._put_device = part_put_device;
 427
 428	slave->mtd._erase = part_erase;
 429	slave->parent = parent;
 430	slave->offset = part->offset;
 431
 432	if (slave->offset == MTDPART_OFS_APPEND)
 433		slave->offset = cur_offset;
 434	if (slave->offset == MTDPART_OFS_NXTBLK) {
 435		tmp = cur_offset;
 436		slave->offset = cur_offset;
 437		remainder = do_div(tmp, wr_alignment);
 438		if (remainder) {
 439			slave->offset += wr_alignment - remainder;
 440			printk(KERN_NOTICE "Moving partition %d: "
 441			       "0x%012llx -> 0x%012llx\n", partno,
 442			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 
 443		}
 444	}
 445	if (slave->offset == MTDPART_OFS_RETAIN) {
 446		slave->offset = cur_offset;
 447		if (parent->size - slave->offset >= slave->mtd.size) {
 448			slave->mtd.size = parent->size - slave->offset
 449							- slave->mtd.size;
 450		} else {
 451			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 452				part->name, parent->size - slave->offset,
 453				slave->mtd.size);
 454			/* register to preserve ordering */
 455			goto out_register;
 456		}
 457	}
 458	if (slave->mtd.size == MTDPART_SIZ_FULL)
 459		slave->mtd.size = parent->size - slave->offset;
 460
 461	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 462		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 
 463
 464	/* let's do some sanity checks */
 465	if (slave->offset >= parent->size) {
 466		/* let's register it anyway to preserve ordering */
 467		slave->offset = 0;
 468		slave->mtd.size = 0;
 469
 470		/* Initialize ->erasesize to make add_mtd_device() happy. */
 471		slave->mtd.erasesize = parent->erasesize;
 472
 473		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 474			part->name);
 475		goto out_register;
 476	}
 477	if (slave->offset + slave->mtd.size > parent->size) {
 478		slave->mtd.size = parent->size - slave->offset;
 479		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 480			part->name, parent->name, (unsigned long long)slave->mtd.size);
 481	}
 
 482	if (parent->numeraseregions > 1) {
 483		/* Deal with variable erase size stuff */
 484		int i, max = parent->numeraseregions;
 485		u64 end = slave->offset + slave->mtd.size;
 486		struct mtd_erase_region_info *regions = parent->eraseregions;
 487
 488		/* Find the first erase regions which is part of this
 489		 * partition. */
 490		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 
 491			;
 492		/* The loop searched for the region _behind_ the first one */
 493		if (i > 0)
 494			i--;
 495
 496		/* Pick biggest erasesize */
 497		for (; i < max && regions[i].offset < end; i++) {
 498			if (slave->mtd.erasesize < regions[i].erasesize) {
 499				slave->mtd.erasesize = regions[i].erasesize;
 500			}
 501		}
 502		BUG_ON(slave->mtd.erasesize == 0);
 503	} else {
 504		/* Single erase size */
 505		slave->mtd.erasesize = parent->erasesize;
 506	}
 507
 508	/*
 509	 * Slave erasesize might differ from the master one if the master
 510	 * exposes several regions with different erasesize. Adjust
 511	 * wr_alignment accordingly.
 512	 */
 513	if (!(slave->mtd.flags & MTD_NO_ERASE))
 514		wr_alignment = slave->mtd.erasesize;
 515
 516	tmp = part_absolute_offset(parent) + slave->offset;
 517	remainder = do_div(tmp, wr_alignment);
 518	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 519		/* Doesn't start on a boundary of major erase size */
 520		/* FIXME: Let it be writable if it is on a boundary of
 521		 * _minor_ erase size though */
 522		slave->mtd.flags &= ~MTD_WRITEABLE;
 523		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
 524			part->name);
 525	}
 526
 527	tmp = part_absolute_offset(parent) + slave->mtd.size;
 528	remainder = do_div(tmp, wr_alignment);
 529	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 530		slave->mtd.flags &= ~MTD_WRITEABLE;
 531		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
 532			part->name);
 533	}
 534
 535	mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
 536	slave->mtd.ecc_step_size = parent->ecc_step_size;
 537	slave->mtd.ecc_strength = parent->ecc_strength;
 538	slave->mtd.bitflip_threshold = parent->bitflip_threshold;
 539
 540	if (parent->_block_isbad) {
 541		uint64_t offs = 0;
 542
 543		while (offs < slave->mtd.size) {
 544			if (mtd_block_isreserved(parent, offs + slave->offset))
 545				slave->mtd.ecc_stats.bbtblocks++;
 546			else if (mtd_block_isbad(parent, offs + slave->offset))
 547				slave->mtd.ecc_stats.badblocks++;
 548			offs += slave->mtd.erasesize;
 549		}
 550	}
 551
 552out_register:
 553	return slave;
 554}
 555
 556static ssize_t mtd_partition_offset_show(struct device *dev,
 557		struct device_attribute *attr, char *buf)
 558{
 559	struct mtd_info *mtd = dev_get_drvdata(dev);
 560	struct mtd_part *part = mtd_to_part(mtd);
 561	return snprintf(buf, PAGE_SIZE, "%llu\n", part->offset);
 562}
 563
 564static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
 
 
 565
 566static const struct attribute *mtd_partition_attrs[] = {
 567	&dev_attr_offset.attr,
 568	NULL
 569};
 570
 571static int mtd_add_partition_attrs(struct mtd_part *new)
 572{
 573	int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
 574	if (ret)
 575		printk(KERN_WARNING
 576		       "mtd: failed to create partition attrs, err=%d\n", ret);
 577	return ret;
 578}
 579
 580int mtd_add_partition(struct mtd_info *parent, const char *name,
 581		      long long offset, long long length)
 582{
 
 
 
 583	struct mtd_partition part;
 584	struct mtd_part *new;
 585	int ret = 0;
 586
 587	/* the direct offset is expected */
 588	if (offset == MTDPART_OFS_APPEND ||
 589	    offset == MTDPART_OFS_NXTBLK)
 590		return -EINVAL;
 591
 592	if (length == MTDPART_SIZ_FULL)
 593		length = parent->size - offset;
 594
 595	if (length <= 0)
 596		return -EINVAL;
 597
 598	memset(&part, 0, sizeof(part));
 599	part.name = name;
 600	part.size = length;
 601	part.offset = offset;
 602
 603	new = allocate_partition(parent, &part, -1, offset);
 604	if (IS_ERR(new))
 605		return PTR_ERR(new);
 606
 607	mutex_lock(&mtd_partitions_mutex);
 608	list_add(&new->list, &mtd_partitions);
 609	mutex_unlock(&mtd_partitions_mutex);
 610
 611	ret = add_mtd_device(&new->mtd);
 612	if (ret)
 613		goto err_remove_part;
 614
 615	mtd_add_partition_attrs(new);
 616
 617	return 0;
 618
 619err_remove_part:
 620	mutex_lock(&mtd_partitions_mutex);
 621	list_del(&new->list);
 622	mutex_unlock(&mtd_partitions_mutex);
 623
 624	free_partition(new);
 625
 626	return ret;
 627}
 628EXPORT_SYMBOL_GPL(mtd_add_partition);
 629
 630/**
 631 * __mtd_del_partition - delete MTD partition
 632 *
 633 * @priv: internal MTD struct for partition to be deleted
 634 *
 635 * This function must be called with the partitions mutex locked.
 636 */
 637static int __mtd_del_partition(struct mtd_part *priv)
 638{
 639	struct mtd_part *child, *next;
 640	int err;
 641
 642	list_for_each_entry_safe(child, next, &mtd_partitions, list) {
 643		if (child->parent == &priv->mtd) {
 644			err = __mtd_del_partition(child);
 645			if (err)
 646				return err;
 647		}
 648	}
 649
 650	sysfs_remove_files(&priv->mtd.dev.kobj, mtd_partition_attrs);
 651
 652	err = del_mtd_device(&priv->mtd);
 
 653	if (err)
 654		return err;
 655
 656	list_del(&priv->list);
 657	free_partition(priv);
 658
 659	return 0;
 660}
 661
 662/*
 663 * This function unregisters and destroy all slave MTD objects which are
 664 * attached to the given MTD object.
 665 */
 666int del_mtd_partitions(struct mtd_info *mtd)
 667{
 668	struct mtd_part *slave, *next;
 669	int ret, err = 0;
 670
 671	mutex_lock(&mtd_partitions_mutex);
 672	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 673		if (slave->parent == mtd) {
 674			ret = __mtd_del_partition(slave);
 675			if (ret < 0)
 676				err = ret;
 
 
 
 
 
 
 677		}
 678	mutex_unlock(&mtd_partitions_mutex);
 679
 680	return err;
 681}
 682
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 683int mtd_del_partition(struct mtd_info *mtd, int partno)
 684{
 685	struct mtd_part *slave, *next;
 686	int ret = -EINVAL;
 687
 688	mutex_lock(&mtd_partitions_mutex);
 689	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 690		if ((slave->parent == mtd) &&
 691		    (slave->mtd.index == partno)) {
 692			ret = __mtd_del_partition(slave);
 693			break;
 694		}
 695	mutex_unlock(&mtd_partitions_mutex);
 
 696
 697	return ret;
 698}
 699EXPORT_SYMBOL_GPL(mtd_del_partition);
 700
 701/*
 702 * This function, given a master MTD object and a partition table, creates
 703 * and registers slave MTD objects which are bound to the master according to
 704 * the partition definitions.
 705 *
 706 * For historical reasons, this function's caller only registers the master
 707 * if the MTD_PARTITIONED_MASTER config option is set.
 708 */
 709
 710int add_mtd_partitions(struct mtd_info *master,
 711		       const struct mtd_partition *parts,
 712		       int nbparts)
 713{
 714	struct mtd_part *slave;
 715	uint64_t cur_offset = 0;
 716	int i, ret;
 717
 718	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 
 719
 720	for (i = 0; i < nbparts; i++) {
 721		slave = allocate_partition(master, parts + i, i, cur_offset);
 722		if (IS_ERR(slave)) {
 723			ret = PTR_ERR(slave);
 724			goto err_del_partitions;
 725		}
 726
 727		mutex_lock(&mtd_partitions_mutex);
 728		list_add(&slave->list, &mtd_partitions);
 729		mutex_unlock(&mtd_partitions_mutex);
 730
 731		ret = add_mtd_device(&slave->mtd);
 732		if (ret) {
 733			mutex_lock(&mtd_partitions_mutex);
 734			list_del(&slave->list);
 735			mutex_unlock(&mtd_partitions_mutex);
 736
 737			free_partition(slave);
 738			goto err_del_partitions;
 739		}
 740
 741		mtd_add_partition_attrs(slave);
 
 742		/* Look for subpartitions */
 743		parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);
 
 
 
 
 744
 745		cur_offset = slave->offset + slave->mtd.size;
 746	}
 747
 748	return 0;
 749
 750err_del_partitions:
 751	del_mtd_partitions(master);
 752
 753	return ret;
 754}
 755
 756static DEFINE_SPINLOCK(part_parser_lock);
 757static LIST_HEAD(part_parsers);
 758
 759static struct mtd_part_parser *mtd_part_parser_get(const char *name)
 760{
 761	struct mtd_part_parser *p, *ret = NULL;
 762
 763	spin_lock(&part_parser_lock);
 764
 765	list_for_each_entry(p, &part_parsers, list)
 766		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 767			ret = p;
 768			break;
 769		}
 770
 771	spin_unlock(&part_parser_lock);
 772
 773	return ret;
 774}
 775
 776static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
 777{
 778	module_put(p->owner);
 779}
 780
 781/*
 782 * Many partition parsers just expected the core to kfree() all their data in
 783 * one chunk. Do that by default.
 784 */
 785static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
 786					    int nr_parts)
 787{
 788	kfree(pparts);
 789}
 790
 791int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
 792{
 793	p->owner = owner;
 794
 795	if (!p->cleanup)
 796		p->cleanup = &mtd_part_parser_cleanup_default;
 797
 798	spin_lock(&part_parser_lock);
 799	list_add(&p->list, &part_parsers);
 800	spin_unlock(&part_parser_lock);
 801
 802	return 0;
 803}
 804EXPORT_SYMBOL_GPL(__register_mtd_parser);
 805
 806void deregister_mtd_parser(struct mtd_part_parser *p)
 807{
 808	spin_lock(&part_parser_lock);
 809	list_del(&p->list);
 810	spin_unlock(&part_parser_lock);
 811}
 812EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 813
 814/*
 815 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 816 * are changing this array!
 817 */
 818static const char * const default_mtd_part_types[] = {
 819	"cmdlinepart",
 820	"ofpart",
 821	NULL
 822};
 823
 824/* Check DT only when looking for subpartitions. */
 825static const char * const default_subpartition_types[] = {
 826	"ofpart",
 827	NULL
 828};
 829
 830static int mtd_part_do_parse(struct mtd_part_parser *parser,
 831			     struct mtd_info *master,
 832			     struct mtd_partitions *pparts,
 833			     struct mtd_part_parser_data *data)
 834{
 835	int ret;
 836
 837	ret = (*parser->parse_fn)(master, &pparts->parts, data);
 838	pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
 839	if (ret <= 0)
 840		return ret;
 841
 842	pr_notice("%d %s partitions found on MTD device %s\n", ret,
 843		  parser->name, master->name);
 844
 845	pparts->nr_parts = ret;
 846	pparts->parser = parser;
 847
 848	return ret;
 849}
 850
 851/**
 852 * mtd_part_get_compatible_parser - find MTD parser by a compatible string
 853 *
 854 * @compat: compatible string describing partitions in a device tree
 855 *
 856 * MTD parsers can specify supported partitions by providing a table of
 857 * compatibility strings. This function finds a parser that advertises support
 858 * for a passed value of "compatible".
 859 */
 860static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)
 861{
 862	struct mtd_part_parser *p, *ret = NULL;
 863
 864	spin_lock(&part_parser_lock);
 865
 866	list_for_each_entry(p, &part_parsers, list) {
 867		const struct of_device_id *matches;
 868
 869		matches = p->of_match_table;
 870		if (!matches)
 871			continue;
 872
 873		for (; matches->compatible[0]; matches++) {
 874			if (!strcmp(matches->compatible, compat) &&
 875			    try_module_get(p->owner)) {
 876				ret = p;
 877				break;
 878			}
 879		}
 880
 881		if (ret)
 882			break;
 883	}
 884
 885	spin_unlock(&part_parser_lock);
 886
 887	return ret;
 888}
 889
 890static int mtd_part_of_parse(struct mtd_info *master,
 891			     struct mtd_partitions *pparts)
 892{
 893	struct mtd_part_parser *parser;
 894	struct device_node *np;
 
 895	struct property *prop;
 
 896	const char *compat;
 897	const char *fixed = "fixed-partitions";
 898	int ret, err = 0;
 899
 
 
 
 
 
 900	np = mtd_get_of_node(master);
 901	if (mtd_is_partition(master))
 902		of_node_get(np);
 903	else
 904		np = of_get_child_by_name(np, "partitions");
 905
 
 
 
 
 
 
 
 
 
 906	of_property_for_each_string(np, "compatible", prop, compat) {
 907		parser = mtd_part_get_compatible_parser(compat);
 908		if (!parser)
 909			continue;
 910		ret = mtd_part_do_parse(parser, master, pparts, NULL);
 911		if (ret > 0) {
 
 912			of_node_put(np);
 913			return ret;
 914		}
 915		mtd_part_parser_put(parser);
 916		if (ret < 0 && !err)
 917			err = ret;
 918	}
 
 919	of_node_put(np);
 920
 921	/*
 922	 * For backward compatibility we have to try the "fixed-partitions"
 923	 * parser. It supports old DT format with partitions specified as a
 924	 * direct subnodes of a flash device DT node without any compatibility
 925	 * specified we could match.
 926	 */
 927	parser = mtd_part_parser_get(fixed);
 928	if (!parser && !request_module("%s", fixed))
 929		parser = mtd_part_parser_get(fixed);
 930	if (parser) {
 931		ret = mtd_part_do_parse(parser, master, pparts, NULL);
 932		if (ret > 0)
 933			return ret;
 934		mtd_part_parser_put(parser);
 935		if (ret < 0 && !err)
 936			err = ret;
 937	}
 938
 939	return err;
 940}
 941
 942/**
 943 * parse_mtd_partitions - parse and register MTD partitions
 944 *
 945 * @master: the master partition (describes whole MTD device)
 946 * @types: names of partition parsers to try or %NULL
 947 * @data: MTD partition parser-specific data
 948 *
 949 * This function tries to find & register partitions on MTD device @master. It
 950 * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
 951 * then the default list of parsers is used. The default list contains only the
 952 * "cmdlinepart" and "ofpart" parsers ATM.
 953 * Note: If there are more then one parser in @types, the kernel only takes the
 954 * partitions parsed out by the first parser.
 955 *
 956 * This function may return:
 957 * o a negative error code in case of failure
 958 * o number of found partitions otherwise
 959 */
 960int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 961			 struct mtd_part_parser_data *data)
 962{
 963	struct mtd_partitions pparts = { };
 964	struct mtd_part_parser *parser;
 965	int ret, err = 0;
 966
 967	if (!types)
 968		types = mtd_is_partition(master) ? default_subpartition_types :
 969			default_mtd_part_types;
 970
 971	for ( ; *types; types++) {
 972		/*
 973		 * ofpart is a special type that means OF partitioning info
 974		 * should be used. It requires a bit different logic so it is
 975		 * handled in a separated function.
 976		 */
 977		if (!strcmp(*types, "ofpart")) {
 978			ret = mtd_part_of_parse(master, &pparts);
 979		} else {
 980			pr_debug("%s: parsing partitions %s\n", master->name,
 981				 *types);
 982			parser = mtd_part_parser_get(*types);
 983			if (!parser && !request_module("%s", *types))
 984				parser = mtd_part_parser_get(*types);
 985			pr_debug("%s: got parser %s\n", master->name,
 986				parser ? parser->name : NULL);
 987			if (!parser)
 988				continue;
 989			ret = mtd_part_do_parse(parser, master, &pparts, data);
 990			if (ret <= 0)
 991				mtd_part_parser_put(parser);
 992		}
 993		/* Found partitions! */
 994		if (ret > 0) {
 995			err = add_mtd_partitions(master, pparts.parts,
 996						 pparts.nr_parts);
 997			mtd_part_parser_cleanup(&pparts);
 998			return err ? err : pparts.nr_parts;
 999		}
1000		/*
1001		 * Stash the first error we see; only report it if no parser
1002		 * succeeds
1003		 */
1004		if (ret < 0 && !err)
1005			err = ret;
1006	}
1007	return err;
1008}
1009
1010void mtd_part_parser_cleanup(struct mtd_partitions *parts)
1011{
1012	const struct mtd_part_parser *parser;
1013
1014	if (!parts)
1015		return;
1016
1017	parser = parts->parser;
1018	if (parser) {
1019		if (parser->cleanup)
1020			parser->cleanup(parts->parts, parts->nr_parts);
1021
1022		mtd_part_parser_put(parser);
1023	}
1024}
1025
1026int mtd_is_partition(const struct mtd_info *mtd)
1027{
1028	struct mtd_part *part;
1029	int ispart = 0;
1030
1031	mutex_lock(&mtd_partitions_mutex);
1032	list_for_each_entry(part, &mtd_partitions, list)
1033		if (&part->mtd == mtd) {
1034			ispart = 1;
1035			break;
1036		}
1037	mutex_unlock(&mtd_partitions_mutex);
1038
1039	return ispart;
1040}
1041EXPORT_SYMBOL_GPL(mtd_is_partition);
1042
1043/* Returns the size of the entire flash chip */
1044uint64_t mtd_get_device_size(const struct mtd_info *mtd)
1045{
1046	if (!mtd_is_partition(mtd))
1047		return mtd->size;
1048
1049	return mtd_get_device_size(mtd_to_part(mtd)->parent);
1050}
1051EXPORT_SYMBOL_GPL(mtd_get_device_size);
v6.8
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Simple MTD partitioning layer
  4 *
  5 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
  6 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
  7 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
  8 */
  9
 10#include <linux/module.h>
 11#include <linux/types.h>
 12#include <linux/kernel.h>
 13#include <linux/slab.h>
 14#include <linux/list.h>
 15#include <linux/kmod.h>
 16#include <linux/mtd/mtd.h>
 17#include <linux/mtd/partitions.h>
 18#include <linux/err.h>
 19#include <linux/of.h>
 20#include <linux/of_platform.h>
 21
 22#include "mtdcore.h"
 23
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 24/*
 25 * MTD methods which simply translate the effective address and pass through
 26 * to the _real_ device.
 27 */
 28
 29static inline void free_partition(struct mtd_info *mtd)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 30{
 31	kfree(mtd->name);
 32	kfree(mtd);
 33}
 34
 35void release_mtd_partition(struct mtd_info *mtd)
 36{
 37	WARN_ON(!list_empty(&mtd->part.node));
 38	free_partition(mtd);
 39}
 40
 41static struct mtd_info *allocate_partition(struct mtd_info *parent,
 42					   const struct mtd_partition *part,
 43					   int partno, uint64_t cur_offset)
 44{
 45	struct mtd_info *master = mtd_get_master(parent);
 46	int wr_alignment = (parent->flags & MTD_NO_ERASE) ?
 47			   master->writesize : master->erasesize;
 48	u64 parent_size = mtd_is_partition(parent) ?
 49			  parent->part.size : parent->size;
 50	struct mtd_info *child;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 51	u32 remainder;
 52	char *name;
 53	u64 tmp;
 54
 55	/* allocate the partition structure */
 56	child = kzalloc(sizeof(*child), GFP_KERNEL);
 57	name = kstrdup(part->name, GFP_KERNEL);
 58	if (!name || !child) {
 59		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 60		       parent->name);
 61		kfree(name);
 62		kfree(child);
 63		return ERR_PTR(-ENOMEM);
 64	}
 65
 66	/* set up the MTD object for this partition */
 67	child->type = parent->type;
 68	child->part.flags = parent->flags & ~part->mask_flags;
 69	child->part.flags |= part->add_flags;
 70	child->flags = child->part.flags;
 71	child->part.size = part->size;
 72	child->writesize = parent->writesize;
 73	child->writebufsize = parent->writebufsize;
 74	child->oobsize = parent->oobsize;
 75	child->oobavail = parent->oobavail;
 76	child->subpage_sft = parent->subpage_sft;
 77
 78	child->name = name;
 79	child->owner = parent->owner;
 80
 81	/* NOTE: Historically, we didn't arrange MTDs as a tree out of
 82	 * concern for showing the same data in multiple partitions.
 83	 * However, it is very useful to have the master node present,
 84	 * so the MTD_PARTITIONED_MASTER option allows that. The master
 85	 * will have device nodes etc only if this is set, so make the
 86	 * parent conditional on that option. Note, this is a way to
 87	 * distinguish between the parent and its partitions in sysfs.
 88	 */
 89	child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
 90			    &parent->dev : parent->dev.parent;
 91	child->dev.of_node = part->of_node;
 92	child->parent = parent;
 93	child->part.offset = part->offset;
 94	INIT_LIST_HEAD(&child->partitions);
 95
 96	if (child->part.offset == MTDPART_OFS_APPEND)
 97		child->part.offset = cur_offset;
 98	if (child->part.offset == MTDPART_OFS_NXTBLK) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 99		tmp = cur_offset;
100		child->part.offset = cur_offset;
101		remainder = do_div(tmp, wr_alignment);
102		if (remainder) {
103			child->part.offset += wr_alignment - remainder;
104			printk(KERN_NOTICE "Moving partition %d: "
105			       "0x%012llx -> 0x%012llx\n", partno,
106			       (unsigned long long)cur_offset,
107			       child->part.offset);
108		}
109	}
110	if (child->part.offset == MTDPART_OFS_RETAIN) {
111		child->part.offset = cur_offset;
112		if (parent_size - child->part.offset >= child->part.size) {
113			child->part.size = parent_size - child->part.offset -
114					   child->part.size;
115		} else {
116			printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
117				part->name, parent_size - child->part.offset,
118				child->part.size);
119			/* register to preserve ordering */
120			goto out_register;
121		}
122	}
123	if (child->part.size == MTDPART_SIZ_FULL)
124		child->part.size = parent_size - child->part.offset;
125
126	printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n",
127	       child->part.offset, child->part.offset + child->part.size,
128	       child->name);
129
130	/* let's do some sanity checks */
131	if (child->part.offset >= parent_size) {
132		/* let's register it anyway to preserve ordering */
133		child->part.offset = 0;
134		child->part.size = 0;
135
136		/* Initialize ->erasesize to make add_mtd_device() happy. */
137		child->erasesize = parent->erasesize;
 
138		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
139			part->name);
140		goto out_register;
141	}
142	if (child->part.offset + child->part.size > parent->size) {
143		child->part.size = parent_size - child->part.offset;
144		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
145			part->name, parent->name, child->part.size);
146	}
147
148	if (parent->numeraseregions > 1) {
149		/* Deal with variable erase size stuff */
150		int i, max = parent->numeraseregions;
151		u64 end = child->part.offset + child->part.size;
152		struct mtd_erase_region_info *regions = parent->eraseregions;
153
154		/* Find the first erase regions which is part of this
155		 * partition. */
156		for (i = 0; i < max && regions[i].offset <= child->part.offset;
157		     i++)
158			;
159		/* The loop searched for the region _behind_ the first one */
160		if (i > 0)
161			i--;
162
163		/* Pick biggest erasesize */
164		for (; i < max && regions[i].offset < end; i++) {
165			if (child->erasesize < regions[i].erasesize)
166				child->erasesize = regions[i].erasesize;
 
167		}
168		BUG_ON(child->erasesize == 0);
169	} else {
170		/* Single erase size */
171		child->erasesize = master->erasesize;
172	}
173
174	/*
175	 * Child erasesize might differ from the parent one if the parent
176	 * exposes several regions with different erasesize. Adjust
177	 * wr_alignment accordingly.
178	 */
179	if (!(child->flags & MTD_NO_ERASE))
180		wr_alignment = child->erasesize;
181
182	tmp = mtd_get_master_ofs(child, 0);
183	remainder = do_div(tmp, wr_alignment);
184	if ((child->flags & MTD_WRITEABLE) && remainder) {
185		/* Doesn't start on a boundary of major erase size */
186		/* FIXME: Let it be writable if it is on a boundary of
187		 * _minor_ erase size though */
188		child->flags &= ~MTD_WRITEABLE;
189		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
190			part->name);
191	}
192
193	tmp = mtd_get_master_ofs(child, 0) + child->part.size;
194	remainder = do_div(tmp, wr_alignment);
195	if ((child->flags & MTD_WRITEABLE) && remainder) {
196		child->flags &= ~MTD_WRITEABLE;
197		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
198			part->name);
199	}
200
201	child->size = child->part.size;
202	child->ecc_step_size = parent->ecc_step_size;
203	child->ecc_strength = parent->ecc_strength;
204	child->bitflip_threshold = parent->bitflip_threshold;
205
206	if (master->_block_isbad) {
207		uint64_t offs = 0;
208
209		while (offs < child->part.size) {
210			if (mtd_block_isreserved(child, offs))
211				child->ecc_stats.bbtblocks++;
212			else if (mtd_block_isbad(child, offs))
213				child->ecc_stats.badblocks++;
214			offs += child->erasesize;
215		}
216	}
217
218out_register:
219	return child;
220}
221
222static ssize_t offset_show(struct device *dev,
223			   struct device_attribute *attr, char *buf)
224{
225	struct mtd_info *mtd = dev_get_drvdata(dev);
 
 
 
226
227	return sysfs_emit(buf, "%lld\n", mtd->part.offset);
228}
229static DEVICE_ATTR_RO(offset);	/* mtd partition offset */
230
231static const struct attribute *mtd_partition_attrs[] = {
232	&dev_attr_offset.attr,
233	NULL
234};
235
236static int mtd_add_partition_attrs(struct mtd_info *new)
237{
238	int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs);
239	if (ret)
240		printk(KERN_WARNING
241		       "mtd: failed to create partition attrs, err=%d\n", ret);
242	return ret;
243}
244
245int mtd_add_partition(struct mtd_info *parent, const char *name,
246		      long long offset, long long length)
247{
248	struct mtd_info *master = mtd_get_master(parent);
249	u64 parent_size = mtd_is_partition(parent) ?
250			  parent->part.size : parent->size;
251	struct mtd_partition part;
252	struct mtd_info *child;
253	int ret = 0;
254
255	/* the direct offset is expected */
256	if (offset == MTDPART_OFS_APPEND ||
257	    offset == MTDPART_OFS_NXTBLK)
258		return -EINVAL;
259
260	if (length == MTDPART_SIZ_FULL)
261		length = parent_size - offset;
262
263	if (length <= 0)
264		return -EINVAL;
265
266	memset(&part, 0, sizeof(part));
267	part.name = name;
268	part.size = length;
269	part.offset = offset;
270
271	child = allocate_partition(parent, &part, -1, offset);
272	if (IS_ERR(child))
273		return PTR_ERR(child);
274
275	mutex_lock(&master->master.partitions_lock);
276	list_add_tail(&child->part.node, &parent->partitions);
277	mutex_unlock(&master->master.partitions_lock);
278
279	ret = add_mtd_device(child);
280	if (ret)
281		goto err_remove_part;
282
283	mtd_add_partition_attrs(child);
284
285	return 0;
286
287err_remove_part:
288	mutex_lock(&master->master.partitions_lock);
289	list_del(&child->part.node);
290	mutex_unlock(&master->master.partitions_lock);
291
292	free_partition(child);
293
294	return ret;
295}
296EXPORT_SYMBOL_GPL(mtd_add_partition);
297
298/**
299 * __mtd_del_partition - delete MTD partition
300 *
301 * @mtd: MTD structure to be deleted
302 *
303 * This function must be called with the partitions mutex locked.
304 */
305static int __mtd_del_partition(struct mtd_info *mtd)
306{
307	struct mtd_info *child, *next;
308	int err;
309
310	list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
311		err = __mtd_del_partition(child);
312		if (err)
313			return err;
 
 
314	}
315
316	sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs);
317
318	list_del_init(&mtd->part.node);
319	err = del_mtd_device(mtd);
320	if (err)
321		return err;
322
 
 
 
323	return 0;
324}
325
326/*
327 * This function unregisters and destroy all slave MTD objects which are
328 * attached to the given MTD object, recursively.
329 */
330static int __del_mtd_partitions(struct mtd_info *mtd)
331{
332	struct mtd_info *child, *next;
333	int ret, err = 0;
334
335	list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {
336		if (mtd_has_partitions(child))
337			__del_mtd_partitions(child);
338
339		pr_info("Deleting %s MTD partition\n", child->name);
340		list_del_init(&child->part.node);
341		ret = del_mtd_device(child);
342		if (ret < 0) {
343			pr_err("Error when deleting partition \"%s\" (%d)\n",
344			       child->name, ret);
345			err = ret;
346			continue;
347		}
348	}
349
350	return err;
351}
352
353int del_mtd_partitions(struct mtd_info *mtd)
354{
355	struct mtd_info *master = mtd_get_master(mtd);
356	int ret;
357
358	pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name);
359
360	mutex_lock(&master->master.partitions_lock);
361	ret = __del_mtd_partitions(mtd);
362	mutex_unlock(&master->master.partitions_lock);
363
364	return ret;
365}
366
367int mtd_del_partition(struct mtd_info *mtd, int partno)
368{
369	struct mtd_info *child, *master = mtd_get_master(mtd);
370	int ret = -EINVAL;
371
372	mutex_lock(&master->master.partitions_lock);
373	list_for_each_entry(child, &mtd->partitions, part.node) {
374		if (child->index == partno) {
375			ret = __mtd_del_partition(child);
 
376			break;
377		}
378	}
379	mutex_unlock(&master->master.partitions_lock);
380
381	return ret;
382}
383EXPORT_SYMBOL_GPL(mtd_del_partition);
384
385/*
386 * This function, given a parent MTD object and a partition table, creates
387 * and registers the child MTD objects which are bound to the parent according
388 * to the partition definitions.
389 *
390 * For historical reasons, this function's caller only registers the parent
391 * if the MTD_PARTITIONED_MASTER config option is set.
392 */
393
394int add_mtd_partitions(struct mtd_info *parent,
395		       const struct mtd_partition *parts,
396		       int nbparts)
397{
398	struct mtd_info *child, *master = mtd_get_master(parent);
399	uint64_t cur_offset = 0;
400	int i, ret;
401
402	printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n",
403	       nbparts, parent->name);
404
405	for (i = 0; i < nbparts; i++) {
406		child = allocate_partition(parent, parts + i, i, cur_offset);
407		if (IS_ERR(child)) {
408			ret = PTR_ERR(child);
409			goto err_del_partitions;
410		}
411
412		mutex_lock(&master->master.partitions_lock);
413		list_add_tail(&child->part.node, &parent->partitions);
414		mutex_unlock(&master->master.partitions_lock);
415
416		ret = add_mtd_device(child);
417		if (ret) {
418			mutex_lock(&master->master.partitions_lock);
419			list_del(&child->part.node);
420			mutex_unlock(&master->master.partitions_lock);
421
422			free_partition(child);
423			goto err_del_partitions;
424		}
425
426		mtd_add_partition_attrs(child);
427
428		/* Look for subpartitions */
429		ret = parse_mtd_partitions(child, parts[i].types, NULL);
430		if (ret < 0) {
431			pr_err("Failed to parse subpartitions: %d\n", ret);
432			goto err_del_partitions;
433		}
434
435		cur_offset = child->part.offset + child->part.size;
436	}
437
438	return 0;
439
440err_del_partitions:
441	del_mtd_partitions(master);
442
443	return ret;
444}
445
446static DEFINE_SPINLOCK(part_parser_lock);
447static LIST_HEAD(part_parsers);
448
449static struct mtd_part_parser *mtd_part_parser_get(const char *name)
450{
451	struct mtd_part_parser *p, *ret = NULL;
452
453	spin_lock(&part_parser_lock);
454
455	list_for_each_entry(p, &part_parsers, list)
456		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
457			ret = p;
458			break;
459		}
460
461	spin_unlock(&part_parser_lock);
462
463	return ret;
464}
465
466static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
467{
468	module_put(p->owner);
469}
470
471/*
472 * Many partition parsers just expected the core to kfree() all their data in
473 * one chunk. Do that by default.
474 */
475static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
476					    int nr_parts)
477{
478	kfree(pparts);
479}
480
481int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
482{
483	p->owner = owner;
484
485	if (!p->cleanup)
486		p->cleanup = &mtd_part_parser_cleanup_default;
487
488	spin_lock(&part_parser_lock);
489	list_add(&p->list, &part_parsers);
490	spin_unlock(&part_parser_lock);
491
492	return 0;
493}
494EXPORT_SYMBOL_GPL(__register_mtd_parser);
495
496void deregister_mtd_parser(struct mtd_part_parser *p)
497{
498	spin_lock(&part_parser_lock);
499	list_del(&p->list);
500	spin_unlock(&part_parser_lock);
501}
502EXPORT_SYMBOL_GPL(deregister_mtd_parser);
503
504/*
505 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
506 * are changing this array!
507 */
508static const char * const default_mtd_part_types[] = {
509	"cmdlinepart",
510	"ofpart",
511	NULL
512};
513
514/* Check DT only when looking for subpartitions. */
515static const char * const default_subpartition_types[] = {
516	"ofpart",
517	NULL
518};
519
520static int mtd_part_do_parse(struct mtd_part_parser *parser,
521			     struct mtd_info *master,
522			     struct mtd_partitions *pparts,
523			     struct mtd_part_parser_data *data)
524{
525	int ret;
526
527	ret = (*parser->parse_fn)(master, &pparts->parts, data);
528	pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
529	if (ret <= 0)
530		return ret;
531
532	pr_notice("%d %s partitions found on MTD device %s\n", ret,
533		  parser->name, master->name);
534
535	pparts->nr_parts = ret;
536	pparts->parser = parser;
537
538	return ret;
539}
540
541/**
542 * mtd_part_get_compatible_parser - find MTD parser by a compatible string
543 *
544 * @compat: compatible string describing partitions in a device tree
545 *
546 * MTD parsers can specify supported partitions by providing a table of
547 * compatibility strings. This function finds a parser that advertises support
548 * for a passed value of "compatible".
549 */
550static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)
551{
552	struct mtd_part_parser *p, *ret = NULL;
553
554	spin_lock(&part_parser_lock);
555
556	list_for_each_entry(p, &part_parsers, list) {
557		const struct of_device_id *matches;
558
559		matches = p->of_match_table;
560		if (!matches)
561			continue;
562
563		for (; matches->compatible[0]; matches++) {
564			if (!strcmp(matches->compatible, compat) &&
565			    try_module_get(p->owner)) {
566				ret = p;
567				break;
568			}
569		}
570
571		if (ret)
572			break;
573	}
574
575	spin_unlock(&part_parser_lock);
576
577	return ret;
578}
579
580static int mtd_part_of_parse(struct mtd_info *master,
581			     struct mtd_partitions *pparts)
582{
583	struct mtd_part_parser *parser;
584	struct device_node *np;
585	struct device_node *child;
586	struct property *prop;
587	struct device *dev;
588	const char *compat;
589	const char *fixed = "fixed-partitions";
590	int ret, err = 0;
591
592	dev = &master->dev;
593	/* Use parent device (controller) if the top level MTD is not registered */
594	if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master))
595		dev = master->dev.parent;
596
597	np = mtd_get_of_node(master);
598	if (mtd_is_partition(master))
599		of_node_get(np);
600	else
601		np = of_get_child_by_name(np, "partitions");
602
603	/*
604	 * Don't create devices that are added to a bus but will never get
605	 * probed. That'll cause fw_devlink to block probing of consumers of
606	 * this partition until the partition device is probed.
607	 */
608	for_each_child_of_node(np, child)
609		if (of_device_is_compatible(child, "nvmem-cells"))
610			of_node_set_flag(child, OF_POPULATED);
611
612	of_property_for_each_string(np, "compatible", prop, compat) {
613		parser = mtd_part_get_compatible_parser(compat);
614		if (!parser)
615			continue;
616		ret = mtd_part_do_parse(parser, master, pparts, NULL);
617		if (ret > 0) {
618			of_platform_populate(np, NULL, NULL, dev);
619			of_node_put(np);
620			return ret;
621		}
622		mtd_part_parser_put(parser);
623		if (ret < 0 && !err)
624			err = ret;
625	}
626	of_platform_populate(np, NULL, NULL, dev);
627	of_node_put(np);
628
629	/*
630	 * For backward compatibility we have to try the "fixed-partitions"
631	 * parser. It supports old DT format with partitions specified as a
632	 * direct subnodes of a flash device DT node without any compatibility
633	 * specified we could match.
634	 */
635	parser = mtd_part_parser_get(fixed);
636	if (!parser && !request_module("%s", fixed))
637		parser = mtd_part_parser_get(fixed);
638	if (parser) {
639		ret = mtd_part_do_parse(parser, master, pparts, NULL);
640		if (ret > 0)
641			return ret;
642		mtd_part_parser_put(parser);
643		if (ret < 0 && !err)
644			err = ret;
645	}
646
647	return err;
648}
649
650/**
651 * parse_mtd_partitions - parse and register MTD partitions
652 *
653 * @master: the master partition (describes whole MTD device)
654 * @types: names of partition parsers to try or %NULL
655 * @data: MTD partition parser-specific data
656 *
657 * This function tries to find & register partitions on MTD device @master. It
658 * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
659 * then the default list of parsers is used. The default list contains only the
660 * "cmdlinepart" and "ofpart" parsers ATM.
661 * Note: If there are more then one parser in @types, the kernel only takes the
662 * partitions parsed out by the first parser.
663 *
664 * This function may return:
665 * o a negative error code in case of failure
666 * o number of found partitions otherwise
667 */
668int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
669			 struct mtd_part_parser_data *data)
670{
671	struct mtd_partitions pparts = { };
672	struct mtd_part_parser *parser;
673	int ret, err = 0;
674
675	if (!types)
676		types = mtd_is_partition(master) ? default_subpartition_types :
677			default_mtd_part_types;
678
679	for ( ; *types; types++) {
680		/*
681		 * ofpart is a special type that means OF partitioning info
682		 * should be used. It requires a bit different logic so it is
683		 * handled in a separated function.
684		 */
685		if (!strcmp(*types, "ofpart")) {
686			ret = mtd_part_of_parse(master, &pparts);
687		} else {
688			pr_debug("%s: parsing partitions %s\n", master->name,
689				 *types);
690			parser = mtd_part_parser_get(*types);
691			if (!parser && !request_module("%s", *types))
692				parser = mtd_part_parser_get(*types);
693			pr_debug("%s: got parser %s\n", master->name,
694				parser ? parser->name : NULL);
695			if (!parser)
696				continue;
697			ret = mtd_part_do_parse(parser, master, &pparts, data);
698			if (ret <= 0)
699				mtd_part_parser_put(parser);
700		}
701		/* Found partitions! */
702		if (ret > 0) {
703			err = add_mtd_partitions(master, pparts.parts,
704						 pparts.nr_parts);
705			mtd_part_parser_cleanup(&pparts);
706			return err ? err : pparts.nr_parts;
707		}
708		/*
709		 * Stash the first error we see; only report it if no parser
710		 * succeeds
711		 */
712		if (ret < 0 && !err)
713			err = ret;
714	}
715	return err;
716}
717
718void mtd_part_parser_cleanup(struct mtd_partitions *parts)
719{
720	const struct mtd_part_parser *parser;
721
722	if (!parts)
723		return;
724
725	parser = parts->parser;
726	if (parser) {
727		if (parser->cleanup)
728			parser->cleanup(parts->parts, parts->nr_parts);
729
730		mtd_part_parser_put(parser);
731	}
732}
733
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
734/* Returns the size of the entire flash chip */
735uint64_t mtd_get_device_size(const struct mtd_info *mtd)
736{
737	struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);
 
738
739	return master->size;
740}
741EXPORT_SYMBOL_GPL(mtd_get_device_size);