[linux-2.6] / drivers / mtd / cmdlinepart.c

/*
 * $Id: cmdlinepart.c,v 1.19 2005/11/07 11:14:19 gleixner Exp $
 *
 * Read flash partition table from command line
 *
 * Copyright 2002 SYSGO Real-Time Solutions GmbH
 *
 * The format for the command line is as follows:
 *
 * mtdparts=<mtddef>[;<mtddef]
 * <mtddef>  := <mtd-id>:<partdef>[,<partdef>]
 * <partdef> := <size>[@offset][<name>][ro]
 * <mtd-id>  := unique name used in mapping driver/device (mtd->name)
 * <size>    := standard linux memsize OR "-" to denote all remaining space
 * <name>    := '(' NAME ')'
 *
 * Examples:
 *
 * 1 NOR Flash, with 1 single writable partition:
 * edb7312-nor:-
 *
 * 1 NOR Flash with 2 partitions, 1 NAND with one
 * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
 */

#include <linux/kernel.h>
#include <linux/slab.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/bootmem.h>

/* error message prefix */
#define ERRP "mtd: "

/* debug macro */
#if 0
#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
#else
#define dbg(x)
#endif


/* special size referring to all the remaining space in a partition */
#define SIZE_REMAINING UINT_MAX
#define OFFSET_CONTINUOUS UINT_MAX

struct cmdline_mtd_partition {
	struct cmdline_mtd_partition *next;
	char *mtd_id;
	int num_parts;
	struct mtd_partition *parts;
};

/* mtdpart_setup() parses into here */
static struct cmdline_mtd_partition *partitions;

/* the command line passed to mtdpart_setupd() */
static char *cmdline;
static int cmdline_parsed = 0;

/*
 * Parse one partition definition for an MTD. Since there can be many
 * comma separated partition definitions, this function calls itself
 * recursively until no more partition definitions are found. Nice side
 * effect: the memory to keep the mtd_partition structs and the names
 * is allocated upon the last definition being found. At that point the
 * syntax has been verified ok.
 */
static struct mtd_partition * newpart(char *s,
                                      char **retptr,
                                      int *num_parts,
                                      int this_part,
                                      unsigned char **extra_mem_ptr,
                                      int extra_mem_size)
{
	struct mtd_partition *parts;
	unsigned long size;
	unsigned long offset = OFFSET_CONTINUOUS;
	char *name;
	int name_len;
	unsigned char *extra_mem;
	char delim;
	unsigned int mask_flags;

	/* fetch the partition size */
	if (*s == '-')
	{	/* assign all remaining space to this partition */
		size = SIZE_REMAINING;
		s++;
	}
	else
	{
		size = memparse(s, &s);
		if (size < PAGE_SIZE)
		{
			printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
			return NULL;
		}
	}

	/* fetch partition name and flags */
	mask_flags = 0; /* this is going to be a regular partition */
	delim = 0;
        /* check for offset */
        if (*s == '@')
	{
                s++;
                offset = memparse(s, &s);
        }
        /* now look for name */
	if (*s == '(')
	{
		delim = ')';
	}

	if (delim)
	{
		char *p;

	    	name = ++s;
		if ((p = strchr(name, delim)) == 0)
		{
			printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
			return NULL;
		}
		name_len = p - name;
		s = p + 1;
	}
	else
	{
	    	name = NULL;
		name_len = 13; /* Partition_000 */
	}

	/* record name length for memory allocation later */
	extra_mem_size += name_len + 1;

        /* test for options */
        if (strncmp(s, "ro", 2) == 0)
	{
		mask_flags |= MTD_WRITEABLE;
		s += 2;
        }

	/* test if more partitions are following */
	if (*s == ',')
	{
		if (size == SIZE_REMAINING)
		{
			printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
			return NULL;
		}
		/* more partitions follow, parse them */
		if ((parts = newpart(s + 1, &s, num_parts,
		                     this_part + 1, &extra_mem, extra_mem_size)) == 0)
		  return NULL;
	}
	else
	{	/* this is the last partition: allocate space for all */
		int alloc_size;

		*num_parts = this_part + 1;
		alloc_size = *num_parts * sizeof(struct mtd_partition) +
			     extra_mem_size;
		parts = kzalloc(alloc_size, GFP_KERNEL);
		if (!parts)
		{
			printk(KERN_ERR ERRP "out of memory\n");
			return NULL;
		}
		extra_mem = (unsigned char *)(parts + *num_parts);
	}
	/* enter this partition (offset will be calculated later if it is zero at this point) */
	parts[this_part].size = size;
	parts[this_part].offset = offset;
	parts[this_part].mask_flags = mask_flags;
	if (name)
	{
		strlcpy(extra_mem, name, name_len + 1);
	}
	else
	{
		sprintf(extra_mem, "Partition_%03d", this_part);
	}
	parts[this_part].name = extra_mem;
	extra_mem += name_len + 1;

	dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
	     this_part,
	     parts[this_part].name,
	     parts[this_part].offset,
	     parts[this_part].size,
	     parts[this_part].mask_flags));

	/* return (updated) pointer to extra_mem memory */
	if (extra_mem_ptr)
	  *extra_mem_ptr = extra_mem;

	/* return (updated) pointer command line string */
	*retptr = s;

	/* return partition table */
	return parts;
}

/*
 * Parse the command line.
 */
static int mtdpart_setup_real(char *s)
{
	cmdline_parsed = 1;

	for( ; s != NULL; )
	{
		struct cmdline_mtd_partition *this_mtd;
		struct mtd_partition *parts;
	    	int mtd_id_len;
		int num_parts;
		char *p, *mtd_id;

	    	mtd_id = s;
		/* fetch <mtd-id> */
		if (!(p = strchr(s, ':')))
		{
			printk(KERN_ERR ERRP "no mtd-id\n");
			return 0;
		}
		mtd_id_len = p - mtd_id;

		dbg(("parsing <%s>\n", p+1));

		/*
		 * parse one mtd. have it reserve memory for the
		 * struct cmdline_mtd_partition and the mtd-id string.
		 */
		parts = newpart(p + 1,		/* cmdline */
				&s,		/* out: updated cmdline ptr */
				&num_parts,	/* out: number of parts */
				0,		/* first partition */
				(unsigned char**)&this_mtd, /* out: extra mem */
				mtd_id_len + 1 + sizeof(*this_mtd) +
				sizeof(void*)-1 /*alignment*/);
		if(!parts)
		{
			/*
			 * An error occurred. We're either:
			 * a) out of memory, or
			 * b) in the middle of the partition spec
			 * Either way, this mtd is hosed and we're
			 * unlikely to succeed in parsing any more
			 */
			 return 0;
		 }

		/* align this_mtd */
		this_mtd = (struct cmdline_mtd_partition *)
			ALIGN((unsigned long)this_mtd, sizeof(void*));
		/* enter results */
		this_mtd->parts = parts;
		this_mtd->num_parts = num_parts;
		this_mtd->mtd_id = (char*)(this_mtd + 1);
		strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);

		/* link into chain */
		this_mtd->next = partitions;
		partitions = this_mtd;

		dbg(("mtdid=<%s> num_parts=<%d>\n",
		     this_mtd->mtd_id, this_mtd->num_parts));


		/* EOS - we're done */
		if (*s == 0)
			break;

		/* does another spec follow? */
		if (*s != ';')
		{
			printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
			return 0;
		}
		s++;
	}
	return 1;
}

/*
 * Main function to be called from the MTD mapping driver/device to
 * obtain the partitioning information. At this point the command line
 * arguments will actually be parsed and turned to struct mtd_partition
 * information. It returns partitions for the requested mtd device, or
 * the first one in the chain if a NULL mtd_id is passed in.
 */
static int parse_cmdline_partitions(struct mtd_info *master,
                             struct mtd_partition **pparts,
                             unsigned long origin)
{
	unsigned long offset;
	int i;
	struct cmdline_mtd_partition *part;
	char *mtd_id = master->name;

	if(!cmdline)
		return -EINVAL;

	/* parse command line */
	if (!cmdline_parsed)
		mtdpart_setup_real(cmdline);

	for(part = partitions; part; part = part->next)
	{
		if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
		{
			for(i = 0, offset = 0; i < part->num_parts; i++)
			{
				if (part->parts[i].offset == OFFSET_CONTINUOUS)
				  part->parts[i].offset = offset;
				else
				  offset = part->parts[i].offset;
				if (part->parts[i].size == SIZE_REMAINING)
				  part->parts[i].size = master->size - offset;
				if (offset + part->parts[i].size > master->size)
				{
					printk(KERN_WARNING ERRP
					       "%s: partitioning exceeds flash size, truncating\n",
					       part->mtd_id);
					part->parts[i].size = master->size - offset;
					part->num_parts = i;
				}
				offset += part->parts[i].size;
			}
			*pparts = part->parts;
			return part->num_parts;
		}
	}
	return -EINVAL;
}


/*
 * This is the handler for our kernel parameter, called from
 * main.c::checksetup(). Note that we can not yet kmalloc() anything,
 * so we only save the commandline for later processing.
 *
 * This function needs to be visible for bootloaders.
 */
static int mtdpart_setup(char *s)
{
	cmdline = s;
	return 1;
}

__setup("mtdparts=", mtdpart_setup);

static struct mtd_part_parser cmdline_parser = {
	.owner = THIS_MODULE,
	.parse_fn = parse_cmdline_partitions,
	.name = "cmdlinepart",
};

static int __init cmdline_parser_init(void)
{
	return register_mtd_parser(&cmdline_parser);
}

module_init(cmdline_parser_init);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
MODULE_DESCRIPTION("Command line configuration of MTD partitions");
Commit	Line	Data
1da177e4	1	/*
97894cda	2	* $Id: cmdlinepart.c,v 1.19 2005/11/07 11:14:19 gleixner Exp $
1da177e4 LT	3	*
	4	* Read flash partition table from command line
	5	*
	6	* Copyright 2002 SYSGO Real-Time Solutions GmbH
	7	*
	8	* The format for the command line is as follows:
97894cda	9	*
1da177e4 LT	10	* mtdparts=<mtddef>[;<mtddef]
	11	* <mtddef> := <mtd-id>:<partdef>[,<partdef>]
	12	* <partdef> := <size>[@offset][<name>][ro]
	13	* <mtd-id> := unique name used in mapping driver/device (mtd->name)
	14	* <size> := standard linux memsize OR "-" to denote all remaining space
	15	* <name> := '(' NAME ')'
97894cda	16	*
1da177e4	17	* Examples:
97894cda	18	*
1da177e4 LT	19	* 1 NOR Flash, with 1 single writable partition:
1da177e4 LT	20	* edb7312-nor:-
97894cda	21	*
1da177e4 LT	22	* 1 NOR Flash with 2 partitions, 1 NAND with one
	23	* edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/slab.h>
	28
	29	#include <linux/mtd/mtd.h>
	30	#include <linux/mtd/partitions.h>
	31	#include <linux/bootmem.h>
	32
	33	/* error message prefix */
	34	#define ERRP "mtd: "
	35
	36	/* debug macro */
	37	#if 0
	38	#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
	39	#else
	40	#define dbg(x)
	41	#endif
	42
	43
	44	/* special size referring to all the remaining space in a partition */
b175d03d AN	45	#define SIZE_REMAINING UINT_MAX
b175d03d AN	46	#define OFFSET_CONTINUOUS UINT_MAX
1da177e4 LT	47
	48	struct cmdline_mtd_partition {
	49	struct cmdline_mtd_partition *next;
	50	char *mtd_id;
	51	int num_parts;
	52	struct mtd_partition *parts;
	53	};
	54
	55	/* mtdpart_setup() parses into here */
	56	static struct cmdline_mtd_partition *partitions;
	57
	58	/* the command line passed to mtdpart_setupd() */
	59	static char *cmdline;
	60	static int cmdline_parsed = 0;
	61
	62	/*
	63	* Parse one partition definition for an MTD. Since there can be many
97894cda	64	* comma separated partition definitions, this function calls itself
1da177e4 LT	65	* recursively until no more partition definitions are found. Nice side
	66	* effect: the memory to keep the mtd_partition structs and the names
	67	* is allocated upon the last definition being found. At that point the
	68	* syntax has been verified ok.
	69	*/
97894cda	70	static struct mtd_partition * newpart(char *s,
1da177e4 LT	71	char **retptr,
1da177e4 LT	72	int *num_parts,
97894cda TG	73	int this_part,
97894cda TG	74	unsigned char **extra_mem_ptr,
1da177e4 LT	75	int extra_mem_size)
	76	{
	77	struct mtd_partition *parts;
	78	unsigned long size;
b175d03d	79	unsigned long offset = OFFSET_CONTINUOUS;
1da177e4 LT	80	char *name;
	81	int name_len;
	82	unsigned char *extra_mem;
	83	char delim;
	84	unsigned int mask_flags;
	85
	86	/* fetch the partition size */
	87	if (*s == '-')
	88	{ /* assign all remaining space to this partition */
	89	size = SIZE_REMAINING;
	90	s++;
	91	}
	92	else
	93	{
	94	size = memparse(s, &s);
	95	if (size < PAGE_SIZE)
	96	{
	97	printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
	98	return NULL;
	99	}
	100	}
	101
	102	/* fetch partition name and flags */
	103	mask_flags = 0; /* this is going to be a regular partition */
	104	delim = 0;
	105	/* check for offset */
97894cda	106	if (*s == '@')
1da177e4 LT	107	{
	108	s++;
	109	offset = memparse(s, &s);
	110	}
	111	/* now look for name */
	112	if (*s == '(')
	113	{
	114	delim = ')';
	115	}
97894cda	116
1da177e4 LT	117	if (delim)
	118	{
	119	char *p;
	120
	121	name = ++s;
	122	if ((p = strchr(name, delim)) == 0)
	123	{
	124	printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
	125	return NULL;
	126	}
	127	name_len = p - name;
	128	s = p + 1;
	129	}
	130	else
	131	{
	132	name = NULL;
	133	name_len = 13; /* Partition_000 */
	134	}
97894cda	135
1da177e4 LT	136	/* record name length for memory allocation later */
	137	extra_mem_size += name_len + 1;
	138
	139	/* test for options */
97894cda	140	if (strncmp(s, "ro", 2) == 0)
1da177e4 LT	141	{
	142	mask_flags \|= MTD_WRITEABLE;
	143	s += 2;
	144	}
	145
	146	/* test if more partitions are following */
	147	if (*s == ',')
	148	{
	149	if (size == SIZE_REMAINING)
	150	{
	151	printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
	152	return NULL;
	153	}
	154	/* more partitions follow, parse them */
97894cda	155	if ((parts = newpart(s + 1, &s, num_parts,
1da177e4 LT	156	this_part + 1, &extra_mem, extra_mem_size)) == 0)
	157	return NULL;
	158	}
	159	else
	160	{ /* this is the last partition: allocate space for all */
	161	int alloc_size;
	162
	163	*num_parts = this_part + 1;
	164	alloc_size = num_parts sizeof(struct mtd_partition) +
	165	extra_mem_size;
95b93a0c	166	parts = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	167	if (!parts)
	168	{
	169	printk(KERN_ERR ERRP "out of memory\n");
	170	return NULL;
	171	}
1da177e4 LT	172	extra_mem = (unsigned char )(parts + num_parts);
	173	}
	174	/* enter this partition (offset will be calculated later if it is zero at this point) */
	175	parts[this_part].size = size;
	176	parts[this_part].offset = offset;
	177	parts[this_part].mask_flags = mask_flags;
	178	if (name)
	179	{
	180	strlcpy(extra_mem, name, name_len + 1);
	181	}
	182	else
	183	{
	184	sprintf(extra_mem, "Partition_%03d", this_part);
	185	}
	186	parts[this_part].name = extra_mem;
	187	extra_mem += name_len + 1;
	188
	189	dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
97894cda	190	this_part,
1da177e4 LT	191	parts[this_part].name,
	192	parts[this_part].offset,
	193	parts[this_part].size,
	194	parts[this_part].mask_flags));
	195
	196	/* return (updated) pointer to extra_mem memory */
	197	if (extra_mem_ptr)
	198	*extra_mem_ptr = extra_mem;
	199
	200	/* return (updated) pointer command line string */
	201	*retptr = s;
	202
	203	/* return partition table */
	204	return parts;
	205	}
	206
97894cda TG	207	/*
97894cda TG	208	* Parse the command line.
1da177e4 LT	209	*/
	210	static int mtdpart_setup_real(char *s)
	211	{
	212	cmdline_parsed = 1;
	213
	214	for( ; s != NULL; )
	215	{
	216	struct cmdline_mtd_partition *this_mtd;
	217	struct mtd_partition *parts;
	218	int mtd_id_len;
	219	int num_parts;
	220	char p, mtd_id;
	221
	222	mtd_id = s;
	223	/* fetch <mtd-id> */
	224	if (!(p = strchr(s, ':')))
	225	{
	226	printk(KERN_ERR ERRP "no mtd-id\n");
	227	return 0;
	228	}
	229	mtd_id_len = p - mtd_id;
	230
	231	dbg(("parsing <%s>\n", p+1));
	232
97894cda	233	/*
1da177e4 LT	234	* parse one mtd. have it reserve memory for the
	235	* struct cmdline_mtd_partition and the mtd-id string.
	236	*/
	237	parts = newpart(p + 1, /* cmdline */
	238	&s, /* out: updated cmdline ptr */
	239	&num_parts, /* out: number of parts */
	240	0, /* first partition */
	241	(unsigned char*)&this_mtd, / out: extra mem */
97894cda	242	mtd_id_len + 1 + sizeof(*this_mtd) +
be76c5fb	243	sizeof(void)-1 /alignment*/);
1da177e4 LT	244	if(!parts)
	245	{
	246	/*
	247	* An error occurred. We're either:
	248	* a) out of memory, or
	249	* b) in the middle of the partition spec
	250	* Either way, this mtd is hosed and we're
	251	* unlikely to succeed in parsing any more
	252	*/
	253	return 0;
	254	}
	255
be76c5fb	256	/* align this_mtd */
97894cda	257	this_mtd = (struct cmdline_mtd_partition *)
be76c5fb	258	ALIGN((unsigned long)this_mtd, sizeof(void*));
97894cda	259	/* enter results */
1da177e4 LT	260	this_mtd->parts = parts;
	261	this_mtd->num_parts = num_parts;
	262	this_mtd->mtd_id = (char*)(this_mtd + 1);
	263	strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
	264
	265	/* link into chain */
97894cda	266	this_mtd->next = partitions;
1da177e4 LT	267	partitions = this_mtd;
1da177e4 LT	268
97894cda	269	dbg(("mtdid=<%s> num_parts=<%d>\n",
1da177e4	270	this_mtd->mtd_id, this_mtd->num_parts));
97894cda	271
1da177e4 LT	272
	273	/* EOS - we're done */
	274	if (*s == 0)
	275	break;
	276
	277	/* does another spec follow? */
	278	if (*s != ';')
	279	{
	280	printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
	281	return 0;
	282	}
	283	s++;
	284	}
	285	return 1;
	286	}
	287
	288	/*
	289	* Main function to be called from the MTD mapping driver/device to
	290	* obtain the partitioning information. At this point the command line
	291	* arguments will actually be parsed and turned to struct mtd_partition
	292	* information. It returns partitions for the requested mtd device, or
	293	* the first one in the chain if a NULL mtd_id is passed in.
	294	*/
97894cda	295	static int parse_cmdline_partitions(struct mtd_info *master,
1da177e4 LT	296	struct mtd_partition **pparts,
	297	unsigned long origin)
	298	{
	299	unsigned long offset;
	300	int i;
	301	struct cmdline_mtd_partition *part;
	302	char *mtd_id = master->name;
	303
	304	if(!cmdline)
	305	return -EINVAL;
	306
	307	/* parse command line */
	308	if (!cmdline_parsed)
	309	mtdpart_setup_real(cmdline);
	310
	311	for(part = partitions; part; part = part->next)
	312	{
	313	if ((!mtd_id) \|\| (!strcmp(part->mtd_id, mtd_id)))
	314	{
	315	for(i = 0, offset = 0; i < part->num_parts; i++)
	316	{
b175d03d	317	if (part->parts[i].offset == OFFSET_CONTINUOUS)
1da177e4 LT	318	part->parts[i].offset = offset;
	319	else
	320	offset = part->parts[i].offset;
	321	if (part->parts[i].size == SIZE_REMAINING)
	322	part->parts[i].size = master->size - offset;
	323	if (offset + part->parts[i].size > master->size)
	324	{
97894cda	325	printk(KERN_WARNING ERRP
1da177e4 LT	326	"%s: partitioning exceeds flash size, truncating\n",
	327	part->mtd_id);
	328	part->parts[i].size = master->size - offset;
	329	part->num_parts = i;
	330	}
	331	offset += part->parts[i].size;
	332	}
	333	*pparts = part->parts;
	334	return part->num_parts;
	335	}
	336	}
	337	return -EINVAL;
	338	}
	339
	340
97894cda TG	341	/*
97894cda TG	342	* This is the handler for our kernel parameter, called from
1da177e4 LT	343	* main.c::checksetup(). Note that we can not yet kmalloc() anything,
	344	* so we only save the commandline for later processing.
	345	*
	346	* This function needs to be visible for bootloaders.
	347	*/
ddacff1f	348	static int mtdpart_setup(char *s)
1da177e4 LT	349	{
	350	cmdline = s;
	351	return 1;
	352	}
	353
	354	__setup("mtdparts=", mtdpart_setup);
	355
	356	static struct mtd_part_parser cmdline_parser = {
	357	.owner = THIS_MODULE,
	358	.parse_fn = parse_cmdline_partitions,
	359	.name = "cmdlinepart",
	360	};
	361
	362	static int __init cmdline_parser_init(void)
	363	{
	364	return register_mtd_parser(&cmdline_parser);
	365	}
	366
	367	module_init(cmdline_parser_init);
	368
	369	MODULE_LICENSE("GPL");
	370	MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
	371	MODULE_DESCRIPTION("Command line configuration of MTD partitions");