Home | History | Annotate | Download | only in mtd
      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * Simple MTD partitioning layer
      4  *
      5  * Copyright  2000 Nicolas Pitre <nico (at) fluxnic.net>
      6  * Copyright  2002 Thomas Gleixner <gleixner (at) linutronix.de>
      7  * Copyright  2000-2010 David Woodhouse <dwmw2 (at) infradead.org>
      8  *
      9  */
     10 
     11 #ifndef __UBOOT__
     12 #include <linux/module.h>
     13 #include <linux/types.h>
     14 #include <linux/kernel.h>
     15 #include <linux/slab.h>
     16 #include <linux/list.h>
     17 #include <linux/kmod.h>
     18 #endif
     19 
     20 #include <common.h>
     21 #include <malloc.h>
     22 #include <linux/errno.h>
     23 #include <linux/compat.h>
     24 #include <ubi_uboot.h>
     25 
     26 #include <linux/mtd/mtd.h>
     27 #include <linux/mtd/partitions.h>
     28 #include <linux/err.h>
     29 
     30 #include "mtdcore.h"
     31 
     32 /* Our partition linked list */
     33 static LIST_HEAD(mtd_partitions);
     34 #ifndef __UBOOT__
     35 static DEFINE_MUTEX(mtd_partitions_mutex);
     36 #else
     37 DEFINE_MUTEX(mtd_partitions_mutex);
     38 #endif
     39 
     40 /* Our partition node structure */
     41 struct mtd_part {
     42 	struct mtd_info mtd;
     43 	struct mtd_info *master;
     44 	uint64_t offset;
     45 	struct list_head list;
     46 };
     47 
     48 /*
     49  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
     50  * the pointer to that structure with this macro.
     51  */
     52 #define PART(x)  ((struct mtd_part *)(x))
     53 
     54 
     55 #ifdef __UBOOT__
     56 /* from mm/util.c */
     57 
     58 /**
     59  * kstrdup - allocate space for and copy an existing string
     60  * @s: the string to duplicate
     61  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
     62  */
     63 char *kstrdup(const char *s, gfp_t gfp)
     64 {
     65 	size_t len;
     66 	char *buf;
     67 
     68 	if (!s)
     69 		return NULL;
     70 
     71 	len = strlen(s) + 1;
     72 	buf = kmalloc(len, gfp);
     73 	if (buf)
     74 		memcpy(buf, s, len);
     75 	return buf;
     76 }
     77 #endif
     78 
     79 /*
     80  * MTD methods which simply translate the effective address and pass through
     81  * to the _real_ device.
     82  */
     83 
     84 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
     85 		size_t *retlen, u_char *buf)
     86 {
     87 	struct mtd_part *part = PART(mtd);
     88 	struct mtd_ecc_stats stats;
     89 	int res;
     90 
     91 	stats = part->master->ecc_stats;
     92 	res = part->master->_read(part->master, from + part->offset, len,
     93 				  retlen, buf);
     94 	if (unlikely(mtd_is_eccerr(res)))
     95 		mtd->ecc_stats.failed +=
     96 			part->master->ecc_stats.failed - stats.failed;
     97 	else
     98 		mtd->ecc_stats.corrected +=
     99 			part->master->ecc_stats.corrected - stats.corrected;
    100 	return res;
    101 }
    102 
    103 #ifndef __UBOOT__
    104 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
    105 		size_t *retlen, void **virt, resource_size_t *phys)
    106 {
    107 	struct mtd_part *part = PART(mtd);
    108 
    109 	return part->master->_point(part->master, from + part->offset, len,
    110 				    retlen, virt, phys);
    111 }
    112 
    113 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
    114 {
    115 	struct mtd_part *part = PART(mtd);
    116 
    117 	return part->master->_unpoint(part->master, from + part->offset, len);
    118 }
    119 #endif
    120 
    121 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
    122 					    unsigned long len,
    123 					    unsigned long offset,
    124 					    unsigned long flags)
    125 {
    126 	struct mtd_part *part = PART(mtd);
    127 
    128 	offset += part->offset;
    129 	return part->master->_get_unmapped_area(part->master, len, offset,
    130 						flags);
    131 }
    132 
    133 static int part_read_oob(struct mtd_info *mtd, loff_t from,
    134 		struct mtd_oob_ops *ops)
    135 {
    136 	struct mtd_part *part = PART(mtd);
    137 	int res;
    138 
    139 	if (from >= mtd->size)
    140 		return -EINVAL;
    141 	if (ops->datbuf && from + ops->len > mtd->size)
    142 		return -EINVAL;
    143 
    144 	/*
    145 	 * If OOB is also requested, make sure that we do not read past the end
    146 	 * of this partition.
    147 	 */
    148 	if (ops->oobbuf) {
    149 		size_t len, pages;
    150 
    151 		if (ops->mode == MTD_OPS_AUTO_OOB)
    152 			len = mtd->oobavail;
    153 		else
    154 			len = mtd->oobsize;
    155 		pages = mtd_div_by_ws(mtd->size, mtd);
    156 		pages -= mtd_div_by_ws(from, mtd);
    157 		if (ops->ooboffs + ops->ooblen > pages * len)
    158 			return -EINVAL;
    159 	}
    160 
    161 	res = part->master->_read_oob(part->master, from + part->offset, ops);
    162 	if (unlikely(res)) {
    163 		if (mtd_is_bitflip(res))
    164 			mtd->ecc_stats.corrected++;
    165 		if (mtd_is_eccerr(res))
    166 			mtd->ecc_stats.failed++;
    167 	}
    168 	return res;
    169 }
    170 
    171 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
    172 		size_t len, size_t *retlen, u_char *buf)
    173 {
    174 	struct mtd_part *part = PART(mtd);
    175 	return part->master->_read_user_prot_reg(part->master, from, len,
    176 						 retlen, buf);
    177 }
    178 
    179 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
    180 				   size_t *retlen, struct otp_info *buf)
    181 {
    182 	struct mtd_part *part = PART(mtd);
    183 	return part->master->_get_user_prot_info(part->master, len, retlen,
    184 						 buf);
    185 }
    186 
    187 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
    188 		size_t len, size_t *retlen, u_char *buf)
    189 {
    190 	struct mtd_part *part = PART(mtd);
    191 	return part->master->_read_fact_prot_reg(part->master, from, len,
    192 						 retlen, buf);
    193 }
    194 
    195 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
    196 				   size_t *retlen, struct otp_info *buf)
    197 {
    198 	struct mtd_part *part = PART(mtd);
    199 	return part->master->_get_fact_prot_info(part->master, len, retlen,
    200 						 buf);
    201 }
    202 
    203 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
    204 		size_t *retlen, const u_char *buf)
    205 {
    206 	struct mtd_part *part = PART(mtd);
    207 	return part->master->_write(part->master, to + part->offset, len,
    208 				    retlen, buf);
    209 }
    210 
    211 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
    212 		size_t *retlen, const u_char *buf)
    213 {
    214 	struct mtd_part *part = PART(mtd);
    215 	return part->master->_panic_write(part->master, to + part->offset, len,
    216 					  retlen, buf);
    217 }
    218 
    219 static int part_write_oob(struct mtd_info *mtd, loff_t to,
    220 		struct mtd_oob_ops *ops)
    221 {
    222 	struct mtd_part *part = PART(mtd);
    223 
    224 	if (to >= mtd->size)
    225 		return -EINVAL;
    226 	if (ops->datbuf && to + ops->len > mtd->size)
    227 		return -EINVAL;
    228 	return part->master->_write_oob(part->master, to + part->offset, ops);
    229 }
    230 
    231 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
    232 		size_t len, size_t *retlen, u_char *buf)
    233 {
    234 	struct mtd_part *part = PART(mtd);
    235 	return part->master->_write_user_prot_reg(part->master, from, len,
    236 						  retlen, buf);
    237 }
    238 
    239 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
    240 		size_t len)
    241 {
    242 	struct mtd_part *part = PART(mtd);
    243 	return part->master->_lock_user_prot_reg(part->master, from, len);
    244 }
    245 
    246 #ifndef __UBOOT__
    247 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
    248 		unsigned long count, loff_t to, size_t *retlen)
    249 {
    250 	struct mtd_part *part = PART(mtd);
    251 	return part->master->_writev(part->master, vecs, count,
    252 				     to + part->offset, retlen);
    253 }
    254 #endif
    255 
    256 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
    257 {
    258 	struct mtd_part *part = PART(mtd);
    259 	int ret;
    260 
    261 	instr->addr += part->offset;
    262 	ret = part->master->_erase(part->master, instr);
    263 	if (ret) {
    264 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
    265 			instr->fail_addr -= part->offset;
    266 		instr->addr -= part->offset;
    267 	}
    268 	return ret;
    269 }
    270 
    271 void mtd_erase_callback(struct erase_info *instr)
    272 {
    273 	if (instr->mtd->_erase == part_erase) {
    274 		struct mtd_part *part = PART(instr->mtd);
    275 
    276 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
    277 			instr->fail_addr -= part->offset;
    278 		instr->addr -= part->offset;
    279 	}
    280 	if (instr->callback)
    281 		instr->callback(instr);
    282 }
    283 EXPORT_SYMBOL_GPL(mtd_erase_callback);
    284 
    285 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
    286 {
    287 	struct mtd_part *part = PART(mtd);
    288 	return part->master->_lock(part->master, ofs + part->offset, len);
    289 }
    290 
    291 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
    292 {
    293 	struct mtd_part *part = PART(mtd);
    294 	return part->master->_unlock(part->master, ofs + part->offset, len);
    295 }
    296 
    297 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
    298 {
    299 	struct mtd_part *part = PART(mtd);
    300 	return part->master->_is_locked(part->master, ofs + part->offset, len);
    301 }
    302 
    303 static void part_sync(struct mtd_info *mtd)
    304 {
    305 	struct mtd_part *part = PART(mtd);
    306 	part->master->_sync(part->master);
    307 }
    308 
    309 #ifndef __UBOOT__
    310 static int part_suspend(struct mtd_info *mtd)
    311 {
    312 	struct mtd_part *part = PART(mtd);
    313 	return part->master->_suspend(part->master);
    314 }
    315 
    316 static void part_resume(struct mtd_info *mtd)
    317 {
    318 	struct mtd_part *part = PART(mtd);
    319 	part->master->_resume(part->master);
    320 }
    321 #endif
    322 
    323 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
    324 {
    325 	struct mtd_part *part = PART(mtd);
    326 	ofs += part->offset;
    327 	return part->master->_block_isreserved(part->master, ofs);
    328 }
    329 
    330 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
    331 {
    332 	struct mtd_part *part = PART(mtd);
    333 	ofs += part->offset;
    334 	return part->master->_block_isbad(part->master, ofs);
    335 }
    336 
    337 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
    338 {
    339 	struct mtd_part *part = PART(mtd);
    340 	int res;
    341 
    342 	ofs += part->offset;
    343 	res = part->master->_block_markbad(part->master, ofs);
    344 	if (!res)
    345 		mtd->ecc_stats.badblocks++;
    346 	return res;
    347 }
    348 
    349 static inline void free_partition(struct mtd_part *p)
    350 {
    351 	kfree(p->mtd.name);
    352 	kfree(p);
    353 }
    354 
    355 /*
    356  * This function unregisters and destroy all slave MTD objects which are
    357  * attached to the given master MTD object.
    358  */
    359 
    360 int del_mtd_partitions(struct mtd_info *master)
    361 {
    362 	struct mtd_part *slave, *next;
    363 	int ret, err = 0;
    364 
    365 	mutex_lock(&mtd_partitions_mutex);
    366 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
    367 		if (slave->master == master) {
    368 			ret = del_mtd_device(&slave->mtd);
    369 			if (ret < 0) {
    370 				err = ret;
    371 				continue;
    372 			}
    373 			list_del(&slave->list);
    374 			free_partition(slave);
    375 		}
    376 	mutex_unlock(&mtd_partitions_mutex);
    377 
    378 	return err;
    379 }
    380 
    381 static struct mtd_part *allocate_partition(struct mtd_info *master,
    382 			const struct mtd_partition *part, int partno,
    383 			uint64_t cur_offset)
    384 {
    385 	struct mtd_part *slave;
    386 	char *name;
    387 
    388 	/* allocate the partition structure */
    389 	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
    390 	name = kstrdup(part->name, GFP_KERNEL);
    391 	if (!name || !slave) {
    392 		printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
    393 		       master->name);
    394 		kfree(name);
    395 		kfree(slave);
    396 		return ERR_PTR(-ENOMEM);
    397 	}
    398 
    399 	/* set up the MTD object for this partition */
    400 	slave->mtd.type = master->type;
    401 	slave->mtd.flags = master->flags & ~part->mask_flags;
    402 	slave->mtd.size = part->size;
    403 	slave->mtd.writesize = master->writesize;
    404 	slave->mtd.writebufsize = master->writebufsize;
    405 	slave->mtd.oobsize = master->oobsize;
    406 	slave->mtd.oobavail = master->oobavail;
    407 	slave->mtd.subpage_sft = master->subpage_sft;
    408 
    409 	slave->mtd.name = name;
    410 	slave->mtd.owner = master->owner;
    411 #ifndef __UBOOT__
    412 	slave->mtd.backing_dev_info = master->backing_dev_info;
    413 
    414 	/* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
    415 	 * to have the same data be in two different partitions.
    416 	 */
    417 	slave->mtd.dev.parent = master->dev.parent;
    418 #endif
    419 
    420 	slave->mtd._read = part_read;
    421 	slave->mtd._write = part_write;
    422 
    423 	if (master->_panic_write)
    424 		slave->mtd._panic_write = part_panic_write;
    425 
    426 #ifndef __UBOOT__
    427 	if (master->_point && master->_unpoint) {
    428 		slave->mtd._point = part_point;
    429 		slave->mtd._unpoint = part_unpoint;
    430 	}
    431 #endif
    432 
    433 	if (master->_get_unmapped_area)
    434 		slave->mtd._get_unmapped_area = part_get_unmapped_area;
    435 	if (master->_read_oob)
    436 		slave->mtd._read_oob = part_read_oob;
    437 	if (master->_write_oob)
    438 		slave->mtd._write_oob = part_write_oob;
    439 	if (master->_read_user_prot_reg)
    440 		slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
    441 	if (master->_read_fact_prot_reg)
    442 		slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
    443 	if (master->_write_user_prot_reg)
    444 		slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
    445 	if (master->_lock_user_prot_reg)
    446 		slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
    447 	if (master->_get_user_prot_info)
    448 		slave->mtd._get_user_prot_info = part_get_user_prot_info;
    449 	if (master->_get_fact_prot_info)
    450 		slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
    451 	if (master->_sync)
    452 		slave->mtd._sync = part_sync;
    453 #ifndef __UBOOT__
    454 	if (!partno && !master->dev.class && master->_suspend &&
    455 	    master->_resume) {
    456 			slave->mtd._suspend = part_suspend;
    457 			slave->mtd._resume = part_resume;
    458 	}
    459 	if (master->_writev)
    460 		slave->mtd._writev = part_writev;
    461 #endif
    462 	if (master->_lock)
    463 		slave->mtd._lock = part_lock;
    464 	if (master->_unlock)
    465 		slave->mtd._unlock = part_unlock;
    466 	if (master->_is_locked)
    467 		slave->mtd._is_locked = part_is_locked;
    468 	if (master->_block_isreserved)
    469 		slave->mtd._block_isreserved = part_block_isreserved;
    470 	if (master->_block_isbad)
    471 		slave->mtd._block_isbad = part_block_isbad;
    472 	if (master->_block_markbad)
    473 		slave->mtd._block_markbad = part_block_markbad;
    474 	slave->mtd._erase = part_erase;
    475 	slave->master = master;
    476 	slave->offset = part->offset;
    477 
    478 	if (slave->offset == MTDPART_OFS_APPEND)
    479 		slave->offset = cur_offset;
    480 	if (slave->offset == MTDPART_OFS_NXTBLK) {
    481 		slave->offset = cur_offset;
    482 		if (mtd_mod_by_eb(cur_offset, master) != 0) {
    483 			/* Round up to next erasesize */
    484 			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
    485 			debug("Moving partition %d: "
    486 			       "0x%012llx -> 0x%012llx\n", partno,
    487 			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
    488 		}
    489 	}
    490 	if (slave->offset == MTDPART_OFS_RETAIN) {
    491 		slave->offset = cur_offset;
    492 		if (master->size - slave->offset >= slave->mtd.size) {
    493 			slave->mtd.size = master->size - slave->offset
    494 							- slave->mtd.size;
    495 		} else {
    496 			debug("mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
    497 				part->name, master->size - slave->offset,
    498 				slave->mtd.size);
    499 			/* register to preserve ordering */
    500 			goto out_register;
    501 		}
    502 	}
    503 	if (slave->mtd.size == MTDPART_SIZ_FULL)
    504 		slave->mtd.size = master->size - slave->offset;
    505 
    506 	debug("0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
    507 		(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
    508 
    509 	/* let's do some sanity checks */
    510 	if (slave->offset >= master->size) {
    511 		/* let's register it anyway to preserve ordering */
    512 		slave->offset = 0;
    513 		slave->mtd.size = 0;
    514 		printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
    515 			part->name);
    516 		goto out_register;
    517 	}
    518 	if (slave->offset + slave->mtd.size > master->size) {
    519 		slave->mtd.size = master->size - slave->offset;
    520 		printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
    521 			part->name, master->name, (unsigned long long)slave->mtd.size);
    522 	}
    523 	if (master->numeraseregions > 1) {
    524 		/* Deal with variable erase size stuff */
    525 		int i, max = master->numeraseregions;
    526 		u64 end = slave->offset + slave->mtd.size;
    527 		struct mtd_erase_region_info *regions = master->eraseregions;
    528 
    529 		/* Find the first erase regions which is part of this
    530 		 * partition. */
    531 		for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
    532 			;
    533 		/* The loop searched for the region _behind_ the first one */
    534 		if (i > 0)
    535 			i--;
    536 
    537 		/* Pick biggest erasesize */
    538 		for (; i < max && regions[i].offset < end; i++) {
    539 			if (slave->mtd.erasesize < regions[i].erasesize) {
    540 				slave->mtd.erasesize = regions[i].erasesize;
    541 			}
    542 		}
    543 		BUG_ON(slave->mtd.erasesize == 0);
    544 	} else {
    545 		/* Single erase size */
    546 		slave->mtd.erasesize = master->erasesize;
    547 	}
    548 
    549 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
    550 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
    551 		/* Doesn't start on a boundary of major erase size */
    552 		/* FIXME: Let it be writable if it is on a boundary of
    553 		 * _minor_ erase size though */
    554 		slave->mtd.flags &= ~MTD_WRITEABLE;
    555 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
    556 			part->name);
    557 	}
    558 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
    559 	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
    560 		slave->mtd.flags &= ~MTD_WRITEABLE;
    561 		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
    562 			part->name);
    563 	}
    564 
    565 	slave->mtd.ecclayout = master->ecclayout;
    566 	slave->mtd.ecc_step_size = master->ecc_step_size;
    567 	slave->mtd.ecc_strength = master->ecc_strength;
    568 	slave->mtd.bitflip_threshold = master->bitflip_threshold;
    569 
    570 	if (master->_block_isbad) {
    571 		uint64_t offs = 0;
    572 
    573 		while (offs < slave->mtd.size) {
    574 			if (mtd_block_isbad(master, offs + slave->offset))
    575 				slave->mtd.ecc_stats.badblocks++;
    576 			offs += slave->mtd.erasesize;
    577 		}
    578 	}
    579 
    580 out_register:
    581 	return slave;
    582 }
    583 
    584 #ifndef __UBOOT__
    585 int mtd_add_partition(struct mtd_info *master, const char *name,
    586 		      long long offset, long long length)
    587 {
    588 	struct mtd_partition part;
    589 	struct mtd_part *p, *new;
    590 	uint64_t start, end;
    591 	int ret = 0;
    592 
    593 	/* the direct offset is expected */
    594 	if (offset == MTDPART_OFS_APPEND ||
    595 	    offset == MTDPART_OFS_NXTBLK)
    596 		return -EINVAL;
    597 
    598 	if (length == MTDPART_SIZ_FULL)
    599 		length = master->size - offset;
    600 
    601 	if (length <= 0)
    602 		return -EINVAL;
    603 
    604 	part.name = name;
    605 	part.size = length;
    606 	part.offset = offset;
    607 	part.mask_flags = 0;
    608 	part.ecclayout = NULL;
    609 
    610 	new = allocate_partition(master, &part, -1, offset);
    611 	if (IS_ERR(new))
    612 		return PTR_ERR(new);
    613 
    614 	start = offset;
    615 	end = offset + length;
    616 
    617 	mutex_lock(&mtd_partitions_mutex);
    618 	list_for_each_entry(p, &mtd_partitions, list)
    619 		if (p->master == master) {
    620 			if ((start >= p->offset) &&
    621 			    (start < (p->offset + p->mtd.size)))
    622 				goto err_inv;
    623 
    624 			if ((end >= p->offset) &&
    625 			    (end < (p->offset + p->mtd.size)))
    626 				goto err_inv;
    627 		}
    628 
    629 	list_add(&new->list, &mtd_partitions);
    630 	mutex_unlock(&mtd_partitions_mutex);
    631 
    632 	add_mtd_device(&new->mtd);
    633 
    634 	return ret;
    635 err_inv:
    636 	mutex_unlock(&mtd_partitions_mutex);
    637 	free_partition(new);
    638 	return -EINVAL;
    639 }
    640 EXPORT_SYMBOL_GPL(mtd_add_partition);
    641 
    642 int mtd_del_partition(struct mtd_info *master, int partno)
    643 {
    644 	struct mtd_part *slave, *next;
    645 	int ret = -EINVAL;
    646 
    647 	mutex_lock(&mtd_partitions_mutex);
    648 	list_for_each_entry_safe(slave, next, &mtd_partitions, list)
    649 		if ((slave->master == master) &&
    650 		    (slave->mtd.index == partno)) {
    651 			ret = del_mtd_device(&slave->mtd);
    652 			if (ret < 0)
    653 				break;
    654 
    655 			list_del(&slave->list);
    656 			free_partition(slave);
    657 			break;
    658 		}
    659 	mutex_unlock(&mtd_partitions_mutex);
    660 
    661 	return ret;
    662 }
    663 EXPORT_SYMBOL_GPL(mtd_del_partition);
    664 #endif
    665 
    666 /*
    667  * This function, given a master MTD object and a partition table, creates
    668  * and registers slave MTD objects which are bound to the master according to
    669  * the partition definitions.
    670  *
    671  * We don't register the master, or expect the caller to have done so,
    672  * for reasons of data integrity.
    673  */
    674 
    675 int add_mtd_partitions(struct mtd_info *master,
    676 		       const struct mtd_partition *parts,
    677 		       int nbparts)
    678 {
    679 	struct mtd_part *slave;
    680 	uint64_t cur_offset = 0;
    681 	int i;
    682 
    683 #ifdef __UBOOT__
    684 	/*
    685 	 * Need to init the list here, since LIST_INIT() does not
    686 	 * work on platforms where relocation has problems (like MIPS
    687 	 * & PPC).
    688 	 */
    689 	if (mtd_partitions.next == NULL)
    690 		INIT_LIST_HEAD(&mtd_partitions);
    691 #endif
    692 
    693 	debug("Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
    694 
    695 	for (i = 0; i < nbparts; i++) {
    696 		slave = allocate_partition(master, parts + i, i, cur_offset);
    697 		if (IS_ERR(slave))
    698 			return PTR_ERR(slave);
    699 
    700 		mutex_lock(&mtd_partitions_mutex);
    701 		list_add(&slave->list, &mtd_partitions);
    702 		mutex_unlock(&mtd_partitions_mutex);
    703 
    704 		add_mtd_device(&slave->mtd);
    705 
    706 		cur_offset = slave->offset + slave->mtd.size;
    707 	}
    708 
    709 	return 0;
    710 }
    711 
    712 #ifndef __UBOOT__
    713 static DEFINE_SPINLOCK(part_parser_lock);
    714 static LIST_HEAD(part_parsers);
    715 
    716 static struct mtd_part_parser *get_partition_parser(const char *name)
    717 {
    718 	struct mtd_part_parser *p, *ret = NULL;
    719 
    720 	spin_lock(&part_parser_lock);
    721 
    722 	list_for_each_entry(p, &part_parsers, list)
    723 		if (!strcmp(p->name, name) && try_module_get(p->owner)) {
    724 			ret = p;
    725 			break;
    726 		}
    727 
    728 	spin_unlock(&part_parser_lock);
    729 
    730 	return ret;
    731 }
    732 
    733 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
    734 
    735 void register_mtd_parser(struct mtd_part_parser *p)
    736 {
    737 	spin_lock(&part_parser_lock);
    738 	list_add(&p->list, &part_parsers);
    739 	spin_unlock(&part_parser_lock);
    740 }
    741 EXPORT_SYMBOL_GPL(register_mtd_parser);
    742 
    743 void deregister_mtd_parser(struct mtd_part_parser *p)
    744 {
    745 	spin_lock(&part_parser_lock);
    746 	list_del(&p->list);
    747 	spin_unlock(&part_parser_lock);
    748 }
    749 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
    750 
    751 /*
    752  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
    753  * are changing this array!
    754  */
    755 static const char * const default_mtd_part_types[] = {
    756 	"cmdlinepart",
    757 	"ofpart",
    758 	NULL
    759 };
    760 
    761 /**
    762  * parse_mtd_partitions - parse MTD partitions
    763  * @master: the master partition (describes whole MTD device)
    764  * @types: names of partition parsers to try or %NULL
    765  * @pparts: array of partitions found is returned here
    766  * @data: MTD partition parser-specific data
    767  *
    768  * This function tries to find partition on MTD device @master. It uses MTD
    769  * partition parsers, specified in @types. However, if @types is %NULL, then
    770  * the default list of parsers is used. The default list contains only the
    771  * "cmdlinepart" and "ofpart" parsers ATM.
    772  * Note: If there are more then one parser in @types, the kernel only takes the
    773  * partitions parsed out by the first parser.
    774  *
    775  * This function may return:
    776  * o a negative error code in case of failure
    777  * o zero if no partitions were found
    778  * o a positive number of found partitions, in which case on exit @pparts will
    779  *   point to an array containing this number of &struct mtd_info objects.
    780  */
    781 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
    782 			 struct mtd_partition **pparts,
    783 			 struct mtd_part_parser_data *data)
    784 {
    785 	struct mtd_part_parser *parser;
    786 	int ret = 0;
    787 
    788 	if (!types)
    789 		types = default_mtd_part_types;
    790 
    791 	for ( ; ret <= 0 && *types; types++) {
    792 		parser = get_partition_parser(*types);
    793 		if (!parser && !request_module("%s", *types))
    794 			parser = get_partition_parser(*types);
    795 		if (!parser)
    796 			continue;
    797 		ret = (*parser->parse_fn)(master, pparts, data);
    798 		put_partition_parser(parser);
    799 		if (ret > 0) {
    800 			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
    801 			       ret, parser->name, master->name);
    802 			break;
    803 		}
    804 	}
    805 	return ret;
    806 }
    807 #endif
    808 
    809 int mtd_is_partition(const struct mtd_info *mtd)
    810 {
    811 	struct mtd_part *part;
    812 	int ispart = 0;
    813 
    814 	mutex_lock(&mtd_partitions_mutex);
    815 	list_for_each_entry(part, &mtd_partitions, list)
    816 		if (&part->mtd == mtd) {
    817 			ispart = 1;
    818 			break;
    819 		}
    820 	mutex_unlock(&mtd_partitions_mutex);
    821 
    822 	return ispart;
    823 }
    824 EXPORT_SYMBOL_GPL(mtd_is_partition);
    825 
    826 /* Returns the size of the entire flash chip */
    827 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
    828 {
    829 	if (!mtd_is_partition(mtd))
    830 		return mtd->size;
    831 
    832 	return PART(mtd)->master->size;
    833 }
    834 EXPORT_SYMBOL_GPL(mtd_get_device_size);
    835