[net-next-2.6.git] / drivers / mtd / cmdlinepart.c

/*
 * 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>]
 *              where <mtd-id> is the name from the "cat /proc/mtd" command
 * <partdef> := <size>[@offset][<name>][ro][lk]
 * <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;
		p = strchr(name, delim);
		if (!p)
		{
			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;
        }

        /* if lk is found do NOT unlock the MTD partition*/
        if (strncmp(s, "lk", 2) == 0)
	{
		mask_flags |= MTD_POWERUP_LOCK;
		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 */
		parts = newpart(s + 1, &s, num_parts, this_part + 1,
				&extra_mem, extra_mem_size);
		if (!parts)
			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;
	const char *mtd_id = master->name;

	/* 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 = kmemdup(part->parts,
					sizeof(*part->parts) * part->num_parts,
					GFP_KERNEL);
			if (!*pparts)
				return -ENOMEM;
			return part->num_parts;
		}
	}
	return 0;
}


/*
 * 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	/*
1da177e4 LT	2	* Read flash partition table from command line
	3	*
	4	* Copyright 2002 SYSGO Real-Time Solutions GmbH
	5	*
	6	* The format for the command line is as follows:
97894cda	7	*
1da177e4 LT	8	* mtdparts=<mtddef>[;<mtddef]
1da177e4 LT	9	* <mtddef> := <mtd-id>:<partdef>[,<partdef>]
a0ee24a0	10	* where <mtd-id> is the name from the "cat /proc/mtd" command
e619a75f	11	* <partdef> := <size>[@offset][<name>][ro][lk]
1da177e4 LT	12	* <mtd-id> := unique name used in mapping driver/device (mtd->name)
	13	* <size> := standard linux memsize OR "-" to denote all remaining space
	14	* <name> := '(' NAME ')'
97894cda	15	*
1da177e4	16	* Examples:
97894cda	17	*
1da177e4 LT	18	* 1 NOR Flash, with 1 single writable partition:
1da177e4 LT	19	* edb7312-nor:-
97894cda	20	*
1da177e4 LT	21	* 1 NOR Flash with 2 partitions, 1 NAND with one
	22	* edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
	23	*/
	24
	25	#include <linux/kernel.h>
	26	#include <linux/slab.h>
	27
	28	#include <linux/mtd/mtd.h>
	29	#include <linux/mtd/partitions.h>
	30	#include <linux/bootmem.h>
	31
	32	/* error message prefix */
	33	#define ERRP "mtd: "
	34
	35	/* debug macro */
	36	#if 0
	37	#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
	38	#else
	39	#define dbg(x)
	40	#endif
	41
	42
	43	/* special size referring to all the remaining space in a partition */
b175d03d AN	44	#define SIZE_REMAINING UINT_MAX
b175d03d AN	45	#define OFFSET_CONTINUOUS UINT_MAX
1da177e4 LT	46
	47	struct cmdline_mtd_partition {
	48	struct cmdline_mtd_partition *next;
	49	char *mtd_id;
	50	int num_parts;
	51	struct mtd_partition *parts;
	52	};
	53
	54	/* mtdpart_setup() parses into here */
	55	static struct cmdline_mtd_partition *partitions;
	56
	57	/* the command line passed to mtdpart_setupd() */
	58	static char *cmdline;
	59	static int cmdline_parsed = 0;
	60
	61	/*
	62	* Parse one partition definition for an MTD. Since there can be many
97894cda	63	* comma separated partition definitions, this function calls itself
1da177e4 LT	64	* recursively until no more partition definitions are found. Nice side
	65	* effect: the memory to keep the mtd_partition structs and the names
	66	* is allocated upon the last definition being found. At that point the
	67	* syntax has been verified ok.
	68	*/
97894cda	69	static struct mtd_partition * newpart(char *s,
1da177e4 LT	70	char **retptr,
1da177e4 LT	71	int *num_parts,
97894cda TG	72	int this_part,
97894cda TG	73	unsigned char **extra_mem_ptr,
1da177e4 LT	74	int extra_mem_size)
	75	{
	76	struct mtd_partition *parts;
	77	unsigned long size;
b175d03d	78	unsigned long offset = OFFSET_CONTINUOUS;
1da177e4 LT	79	char *name;
	80	int name_len;
	81	unsigned char *extra_mem;
	82	char delim;
	83	unsigned int mask_flags;
	84
	85	/* fetch the partition size */
	86	if (*s == '-')
	87	{ /* assign all remaining space to this partition */
	88	size = SIZE_REMAINING;
	89	s++;
	90	}
	91	else
	92	{
	93	size = memparse(s, &s);
	94	if (size < PAGE_SIZE)
	95	{
	96	printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
	97	return NULL;
	98	}
	99	}
	100
	101	/* fetch partition name and flags */
	102	mask_flags = 0; /* this is going to be a regular partition */
	103	delim = 0;
	104	/* check for offset */
97894cda	105	if (*s == '@')
1da177e4 LT	106	{
	107	s++;
	108	offset = memparse(s, &s);
	109	}
	110	/* now look for name */
	111	if (*s == '(')
	112	{
	113	delim = ')';
	114	}
97894cda	115
1da177e4 LT	116	if (delim)
	117	{
	118	char *p;
	119
	120	name = ++s;
ed262c4f AB	121	p = strchr(name, delim);
ed262c4f AB	122	if (!p)
1da177e4 LT	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
e619a75f JT	146	/* if lk is found do NOT unlock the MTD partition*/
	147	if (strncmp(s, "lk", 2) == 0)
	148	{
	149	mask_flags \|= MTD_POWERUP_LOCK;
	150	s += 2;
	151	}
	152
1da177e4 LT	153	/* test if more partitions are following */
	154	if (*s == ',')
	155	{
	156	if (size == SIZE_REMAINING)
	157	{
	158	printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
	159	return NULL;
	160	}
	161	/* more partitions follow, parse them */
ed262c4f AB	162	parts = newpart(s + 1, &s, num_parts, this_part + 1,
	163	&extra_mem, extra_mem_size);
	164	if (!parts)
	165	return NULL;
1da177e4 LT	166	}
	167	else
	168	{ /* this is the last partition: allocate space for all */
	169	int alloc_size;
	170
	171	*num_parts = this_part + 1;
	172	alloc_size = num_parts sizeof(struct mtd_partition) +
	173	extra_mem_size;
95b93a0c	174	parts = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	175	if (!parts)
	176	{
	177	printk(KERN_ERR ERRP "out of memory\n");
	178	return NULL;
	179	}
1da177e4 LT	180	extra_mem = (unsigned char )(parts + num_parts);
	181	}
	182	/* enter this partition (offset will be calculated later if it is zero at this point) */
	183	parts[this_part].size = size;
	184	parts[this_part].offset = offset;
	185	parts[this_part].mask_flags = mask_flags;
	186	if (name)
	187	{
	188	strlcpy(extra_mem, name, name_len + 1);
	189	}
	190	else
	191	{
	192	sprintf(extra_mem, "Partition_%03d", this_part);
	193	}
	194	parts[this_part].name = extra_mem;
	195	extra_mem += name_len + 1;
	196
	197	dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
97894cda	198	this_part,
1da177e4 LT	199	parts[this_part].name,
	200	parts[this_part].offset,
	201	parts[this_part].size,
	202	parts[this_part].mask_flags));
	203
	204	/* return (updated) pointer to extra_mem memory */
	205	if (extra_mem_ptr)
	206	*extra_mem_ptr = extra_mem;
	207
	208	/* return (updated) pointer command line string */
	209	*retptr = s;
	210
	211	/* return partition table */
	212	return parts;
	213	}
	214
97894cda TG	215	/*
97894cda TG	216	* Parse the command line.
1da177e4 LT	217	*/
	218	static int mtdpart_setup_real(char *s)
	219	{
	220	cmdline_parsed = 1;
	221
	222	for( ; s != NULL; )
	223	{
	224	struct cmdline_mtd_partition *this_mtd;
	225	struct mtd_partition *parts;
	226	int mtd_id_len;
	227	int num_parts;
	228	char p, mtd_id;
	229
	230	mtd_id = s;
	231	/* fetch <mtd-id> */
	232	if (!(p = strchr(s, ':')))
	233	{
	234	printk(KERN_ERR ERRP "no mtd-id\n");
	235	return 0;
	236	}
	237	mtd_id_len = p - mtd_id;
	238
	239	dbg(("parsing <%s>\n", p+1));
	240
97894cda	241	/*
1da177e4 LT	242	* parse one mtd. have it reserve memory for the
	243	* struct cmdline_mtd_partition and the mtd-id string.
	244	*/
	245	parts = newpart(p + 1, /* cmdline */
	246	&s, /* out: updated cmdline ptr */
	247	&num_parts, /* out: number of parts */
	248	0, /* first partition */
	249	(unsigned char*)&this_mtd, / out: extra mem */
97894cda	250	mtd_id_len + 1 + sizeof(*this_mtd) +
be76c5fb	251	sizeof(void)-1 /alignment*/);
1da177e4 LT	252	if(!parts)
	253	{
	254	/*
	255	* An error occurred. We're either:
	256	* a) out of memory, or
	257	* b) in the middle of the partition spec
	258	* Either way, this mtd is hosed and we're
	259	* unlikely to succeed in parsing any more
	260	*/
	261	return 0;
	262	}
	263
be76c5fb	264	/* align this_mtd */
97894cda	265	this_mtd = (struct cmdline_mtd_partition *)
be76c5fb	266	ALIGN((unsigned long)this_mtd, sizeof(void*));
97894cda	267	/* enter results */
1da177e4 LT	268	this_mtd->parts = parts;
	269	this_mtd->num_parts = num_parts;
	270	this_mtd->mtd_id = (char*)(this_mtd + 1);
	271	strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
	272
	273	/* link into chain */
97894cda	274	this_mtd->next = partitions;
1da177e4 LT	275	partitions = this_mtd;
1da177e4 LT	276
97894cda	277	dbg(("mtdid=<%s> num_parts=<%d>\n",
1da177e4	278	this_mtd->mtd_id, this_mtd->num_parts));
97894cda	279
1da177e4 LT	280
	281	/* EOS - we're done */
	282	if (*s == 0)
	283	break;
	284
	285	/* does another spec follow? */
	286	if (*s != ';')
	287	{
	288	printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
	289	return 0;
	290	}
	291	s++;
	292	}
	293	return 1;
	294	}
	295
	296	/*
	297	* Main function to be called from the MTD mapping driver/device to
	298	* obtain the partitioning information. At this point the command line
	299	* arguments will actually be parsed and turned to struct mtd_partition
	300	* information. It returns partitions for the requested mtd device, or
	301	* the first one in the chain if a NULL mtd_id is passed in.
	302	*/
97894cda	303	static int parse_cmdline_partitions(struct mtd_info *master,
1da177e4 LT	304	struct mtd_partition **pparts,
	305	unsigned long origin)
	306	{
	307	unsigned long offset;
	308	int i;
	309	struct cmdline_mtd_partition *part;
36560d25	310	const char *mtd_id = master->name;
1da177e4	311
1da177e4 LT	312	/* parse command line */
	313	if (!cmdline_parsed)
	314	mtdpart_setup_real(cmdline);
	315
	316	for(part = partitions; part; part = part->next)
	317	{
	318	if ((!mtd_id) \|\| (!strcmp(part->mtd_id, mtd_id)))
	319	{
	320	for(i = 0, offset = 0; i < part->num_parts; i++)
	321	{
b175d03d	322	if (part->parts[i].offset == OFFSET_CONTINUOUS)
1da177e4 LT	323	part->parts[i].offset = offset;
	324	else
	325	offset = part->parts[i].offset;
	326	if (part->parts[i].size == SIZE_REMAINING)
	327	part->parts[i].size = master->size - offset;
	328	if (offset + part->parts[i].size > master->size)
	329	{
97894cda	330	printk(KERN_WARNING ERRP
1da177e4 LT	331	"%s: partitioning exceeds flash size, truncating\n",
	332	part->mtd_id);
	333	part->parts[i].size = master->size - offset;
	334	part->num_parts = i;
	335	}
	336	offset += part->parts[i].size;
	337	}
17b536cc AN	338	*pparts = kmemdup(part->parts,
	339	sizeof(part->parts) part->num_parts,
	340	GFP_KERNEL);
	341	if (!*pparts)
	342	return -ENOMEM;
1da177e4 LT	343	return part->num_parts;
	344	}
	345	}
b0d06afb	346	return 0;
1da177e4 LT	347	}
	348
	349
97894cda TG	350	/*
97894cda TG	351	* This is the handler for our kernel parameter, called from
1da177e4 LT	352	* main.c::checksetup(). Note that we can not yet kmalloc() anything,
	353	* so we only save the commandline for later processing.
	354	*
	355	* This function needs to be visible for bootloaders.
	356	*/
ddacff1f	357	static int mtdpart_setup(char *s)
1da177e4 LT	358	{
	359	cmdline = s;
	360	return 1;
	361	}
	362
	363	__setup("mtdparts=", mtdpart_setup);
	364
	365	static struct mtd_part_parser cmdline_parser = {
	366	.owner = THIS_MODULE,
	367	.parse_fn = parse_cmdline_partitions,
	368	.name = "cmdlinepart",
	369	};
	370
	371	static int __init cmdline_parser_init(void)
	372	{
	373	return register_mtd_parser(&cmdline_parser);
	374	}
	375
	376	module_init(cmdline_parser_init);
	377
	378	MODULE_LICENSE("GPL");
	379	MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
	380	MODULE_DESCRIPTION("Command line configuration of MTD partitions");