[GitHub/mt8127/android_kernel_alcatel_ttab.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>]
 * <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 = part->parts;
			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>]
e619a75f	10	* <partdef> := <size>[@offset][<name>][ro][lk]
1da177e4 LT	11	* <mtd-id> := unique name used in mapping driver/device (mtd->name)
	12	* <size> := standard linux memsize OR "-" to denote all remaining space
	13	* <name> := '(' NAME ')'
97894cda	14	*
1da177e4	15	* Examples:
97894cda	16	*
1da177e4 LT	17	* 1 NOR Flash, with 1 single writable partition:
1da177e4 LT	18	* edb7312-nor:-
97894cda	19	*
1da177e4 LT	20	* 1 NOR Flash with 2 partitions, 1 NAND with one
	21	* edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/slab.h>
	26
	27	#include <linux/mtd/mtd.h>
	28	#include <linux/mtd/partitions.h>
	29	#include <linux/bootmem.h>
	30
	31	/* error message prefix */
	32	#define ERRP "mtd: "
	33
	34	/* debug macro */
	35	#if 0
	36	#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
	37	#else
	38	#define dbg(x)
	39	#endif
	40
	41
	42	/* special size referring to all the remaining space in a partition */
b175d03d AN	43	#define SIZE_REMAINING UINT_MAX
b175d03d AN	44	#define OFFSET_CONTINUOUS UINT_MAX
1da177e4 LT	45
	46	struct cmdline_mtd_partition {
	47	struct cmdline_mtd_partition *next;
	48	char *mtd_id;
	49	int num_parts;
	50	struct mtd_partition *parts;
	51	};
	52
	53	/* mtdpart_setup() parses into here */
	54	static struct cmdline_mtd_partition *partitions;
	55
	56	/* the command line passed to mtdpart_setupd() */
	57	static char *cmdline;
	58	static int cmdline_parsed = 0;
	59
	60	/*
	61	* Parse one partition definition for an MTD. Since there can be many
97894cda	62	* comma separated partition definitions, this function calls itself
1da177e4 LT	63	* recursively until no more partition definitions are found. Nice side
	64	* effect: the memory to keep the mtd_partition structs and the names
	65	* is allocated upon the last definition being found. At that point the
	66	* syntax has been verified ok.
	67	*/
97894cda	68	static struct mtd_partition * newpart(char *s,
1da177e4 LT	69	char **retptr,
1da177e4 LT	70	int *num_parts,
97894cda TG	71	int this_part,
97894cda TG	72	unsigned char **extra_mem_ptr,
1da177e4 LT	73	int extra_mem_size)
	74	{
	75	struct mtd_partition *parts;
	76	unsigned long size;
b175d03d	77	unsigned long offset = OFFSET_CONTINUOUS;
1da177e4 LT	78	char *name;
	79	int name_len;
	80	unsigned char *extra_mem;
	81	char delim;
	82	unsigned int mask_flags;
	83
	84	/* fetch the partition size */
	85	if (*s == '-')
	86	{ /* assign all remaining space to this partition */
	87	size = SIZE_REMAINING;
	88	s++;
	89	}
	90	else
	91	{
	92	size = memparse(s, &s);
	93	if (size < PAGE_SIZE)
	94	{
	95	printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
	96	return NULL;
	97	}
	98	}
	99
	100	/* fetch partition name and flags */
	101	mask_flags = 0; /* this is going to be a regular partition */
	102	delim = 0;
	103	/* check for offset */
97894cda	104	if (*s == '@')
1da177e4 LT	105	{
	106	s++;
	107	offset = memparse(s, &s);
	108	}
	109	/* now look for name */
	110	if (*s == '(')
	111	{
	112	delim = ')';
	113	}
97894cda	114
1da177e4 LT	115	if (delim)
	116	{
	117	char *p;
	118
	119	name = ++s;
ed262c4f AB	120	p = strchr(name, delim);
ed262c4f AB	121	if (!p)
1da177e4 LT	122	{
	123	printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
	124	return NULL;
	125	}
	126	name_len = p - name;
	127	s = p + 1;
	128	}
	129	else
	130	{
	131	name = NULL;
	132	name_len = 13; /* Partition_000 */
	133	}
97894cda	134
1da177e4 LT	135	/* record name length for memory allocation later */
	136	extra_mem_size += name_len + 1;
	137
	138	/* test for options */
97894cda	139	if (strncmp(s, "ro", 2) == 0)
1da177e4 LT	140	{
	141	mask_flags \|= MTD_WRITEABLE;
	142	s += 2;
	143	}
	144
e619a75f JT	145	/* if lk is found do NOT unlock the MTD partition*/
	146	if (strncmp(s, "lk", 2) == 0)
	147	{
	148	mask_flags \|= MTD_POWERUP_LOCK;
	149	s += 2;
	150	}
	151
1da177e4 LT	152	/* test if more partitions are following */
	153	if (*s == ',')
	154	{
	155	if (size == SIZE_REMAINING)
	156	{
	157	printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
	158	return NULL;
	159	}
	160	/* more partitions follow, parse them */
ed262c4f AB	161	parts = newpart(s + 1, &s, num_parts, this_part + 1,
	162	&extra_mem, extra_mem_size);
	163	if (!parts)
	164	return NULL;
1da177e4 LT	165	}
	166	else
	167	{ /* this is the last partition: allocate space for all */
	168	int alloc_size;
	169
	170	*num_parts = this_part + 1;
	171	alloc_size = num_parts sizeof(struct mtd_partition) +
	172	extra_mem_size;
95b93a0c	173	parts = kzalloc(alloc_size, GFP_KERNEL);
1da177e4 LT	174	if (!parts)
	175	{
	176	printk(KERN_ERR ERRP "out of memory\n");
	177	return NULL;
	178	}
1da177e4 LT	179	extra_mem = (unsigned char )(parts + num_parts);
	180	}
	181	/* enter this partition (offset will be calculated later if it is zero at this point) */
	182	parts[this_part].size = size;
	183	parts[this_part].offset = offset;
	184	parts[this_part].mask_flags = mask_flags;
	185	if (name)
	186	{
	187	strlcpy(extra_mem, name, name_len + 1);
	188	}
	189	else
	190	{
	191	sprintf(extra_mem, "Partition_%03d", this_part);
	192	}
	193	parts[this_part].name = extra_mem;
	194	extra_mem += name_len + 1;
	195
	196	dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
97894cda	197	this_part,
1da177e4 LT	198	parts[this_part].name,
	199	parts[this_part].offset,
	200	parts[this_part].size,
	201	parts[this_part].mask_flags));
	202
	203	/* return (updated) pointer to extra_mem memory */
	204	if (extra_mem_ptr)
	205	*extra_mem_ptr = extra_mem;
	206
	207	/* return (updated) pointer command line string */
	208	*retptr = s;
	209
	210	/* return partition table */
	211	return parts;
	212	}
	213
97894cda TG	214	/*
97894cda TG	215	* Parse the command line.
1da177e4 LT	216	*/
	217	static int mtdpart_setup_real(char *s)
	218	{
	219	cmdline_parsed = 1;
	220
	221	for( ; s != NULL; )
	222	{
	223	struct cmdline_mtd_partition *this_mtd;
	224	struct mtd_partition *parts;
	225	int mtd_id_len;
	226	int num_parts;
	227	char p, mtd_id;
	228
	229	mtd_id = s;
	230	/* fetch <mtd-id> */
	231	if (!(p = strchr(s, ':')))
	232	{
	233	printk(KERN_ERR ERRP "no mtd-id\n");
	234	return 0;
	235	}
	236	mtd_id_len = p - mtd_id;
	237
	238	dbg(("parsing <%s>\n", p+1));
	239
97894cda	240	/*
1da177e4 LT	241	* parse one mtd. have it reserve memory for the
	242	* struct cmdline_mtd_partition and the mtd-id string.
	243	*/
	244	parts = newpart(p + 1, /* cmdline */
	245	&s, /* out: updated cmdline ptr */
	246	&num_parts, /* out: number of parts */
	247	0, /* first partition */
	248	(unsigned char*)&this_mtd, / out: extra mem */
97894cda	249	mtd_id_len + 1 + sizeof(*this_mtd) +
be76c5fb	250	sizeof(void)-1 /alignment*/);
1da177e4 LT	251	if(!parts)
	252	{
	253	/*
	254	* An error occurred. We're either:
	255	* a) out of memory, or
	256	* b) in the middle of the partition spec
	257	* Either way, this mtd is hosed and we're
	258	* unlikely to succeed in parsing any more
	259	*/
	260	return 0;
	261	}
	262
be76c5fb	263	/* align this_mtd */
97894cda	264	this_mtd = (struct cmdline_mtd_partition *)
be76c5fb	265	ALIGN((unsigned long)this_mtd, sizeof(void*));
97894cda	266	/* enter results */
1da177e4 LT	267	this_mtd->parts = parts;
	268	this_mtd->num_parts = num_parts;
	269	this_mtd->mtd_id = (char*)(this_mtd + 1);
	270	strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
	271
	272	/* link into chain */
97894cda	273	this_mtd->next = partitions;
1da177e4 LT	274	partitions = this_mtd;
1da177e4 LT	275
97894cda	276	dbg(("mtdid=<%s> num_parts=<%d>\n",
1da177e4	277	this_mtd->mtd_id, this_mtd->num_parts));
97894cda	278
1da177e4 LT	279
	280	/* EOS - we're done */
	281	if (*s == 0)
	282	break;
	283
	284	/* does another spec follow? */
	285	if (*s != ';')
	286	{
	287	printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
	288	return 0;
	289	}
	290	s++;
	291	}
	292	return 1;
	293	}
	294
	295	/*
	296	* Main function to be called from the MTD mapping driver/device to
	297	* obtain the partitioning information. At this point the command line
	298	* arguments will actually be parsed and turned to struct mtd_partition
	299	* information. It returns partitions for the requested mtd device, or
	300	* the first one in the chain if a NULL mtd_id is passed in.
	301	*/
97894cda	302	static int parse_cmdline_partitions(struct mtd_info *master,
1da177e4 LT	303	struct mtd_partition **pparts,
	304	unsigned long origin)
	305	{
	306	unsigned long offset;
	307	int i;
	308	struct cmdline_mtd_partition *part;
36560d25	309	const char *mtd_id = master->name;
1da177e4	310
1da177e4 LT	311	/* parse command line */
	312	if (!cmdline_parsed)
	313	mtdpart_setup_real(cmdline);
	314
	315	for(part = partitions; part; part = part->next)
	316	{
	317	if ((!mtd_id) \|\| (!strcmp(part->mtd_id, mtd_id)))
	318	{
	319	for(i = 0, offset = 0; i < part->num_parts; i++)
	320	{
b175d03d	321	if (part->parts[i].offset == OFFSET_CONTINUOUS)
1da177e4 LT	322	part->parts[i].offset = offset;
	323	else
	324	offset = part->parts[i].offset;
	325	if (part->parts[i].size == SIZE_REMAINING)
	326	part->parts[i].size = master->size - offset;
	327	if (offset + part->parts[i].size > master->size)
	328	{
97894cda	329	printk(KERN_WARNING ERRP
1da177e4 LT	330	"%s: partitioning exceeds flash size, truncating\n",
	331	part->mtd_id);
	332	part->parts[i].size = master->size - offset;
	333	part->num_parts = i;
	334	}
	335	offset += part->parts[i].size;
	336	}
	337	*pparts = part->parts;
	338	return part->num_parts;
	339	}
	340	}
b0d06afb	341	return 0;
1da177e4 LT	342	}
	343
	344
97894cda TG	345	/*
97894cda TG	346	* This is the handler for our kernel parameter, called from
1da177e4 LT	347	* main.c::checksetup(). Note that we can not yet kmalloc() anything,
	348	* so we only save the commandline for later processing.
	349	*
	350	* This function needs to be visible for bootloaders.
	351	*/
ddacff1f	352	static int mtdpart_setup(char *s)
1da177e4 LT	353	{
	354	cmdline = s;
	355	return 1;
	356	}
	357
	358	__setup("mtdparts=", mtdpart_setup);
	359
	360	static struct mtd_part_parser cmdline_parser = {
	361	.owner = THIS_MODULE,
	362	.parse_fn = parse_cmdline_partitions,
	363	.name = "cmdlinepart",
	364	};
	365
	366	static int __init cmdline_parser_init(void)
	367	{
	368	return register_mtd_parser(&cmdline_parser);
	369	}
	370
	371	module_init(cmdline_parser_init);
	372
	373	MODULE_LICENSE("GPL");
	374	MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
	375	MODULE_DESCRIPTION("Command line configuration of MTD partitions");