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Commit 1eeef2d7 authored by Chris Packham's avatar Chris Packham Committed by Brian Norris
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mtd: handle partitioning on devices with 0 erasesize 



erasesize is meaningful for flash devices but for SRAM there is no
concept of an erase block so erasesize is set to 0. When partitioning
these devices instead of ensuring partitions fall on erasesize
boundaries we ensure they fall on writesize boundaries.

Helped-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarChris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent c46adf09

drivers/mtd/mtdpart.c

+17 −9
Original line number Original line Diff line number Diff line
@@ -393,8 +393,12 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, 
			const struct mtd_partition *part, int partno,

			const struct mtd_partition *part, int partno,

			uint64_t cur_offset)

			uint64_t cur_offset)

{

{

	int wr_alignment = (master->flags & MTD_NO_ERASE) ? master->writesize:

							    master->erasesize;

	struct mtd_part *slave;

	struct mtd_part *slave;

	u32 remainder;

	char *name;

	char *name;

	u64 tmp;





	/* allocate the partition structure */

	/* allocate the partition structure */

	slave = kzalloc(sizeof(*slave), GFP_KERNEL);

	slave = kzalloc(sizeof(*slave), GFP_KERNEL);
@@ -499,10 +503,11 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, 
	if (slave->offset == MTDPART_OFS_APPEND)

	if (slave->offset == MTDPART_OFS_APPEND)

		slave->offset = cur_offset;

		slave->offset = cur_offset;

	if (slave->offset == MTDPART_OFS_NXTBLK) {

	if (slave->offset == MTDPART_OFS_NXTBLK) {

		tmp = cur_offset;

		slave->offset = cur_offset;

		slave->offset = cur_offset;

		if (mtd_mod_by_eb(cur_offset, master) != 0) {

		remainder = do_div(tmp, wr_alignment);

			/* Round up to next erasesize */

		if (remainder) {

			slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;

			slave->offset += wr_alignment - remainder;

			printk(KERN_NOTICE "Moving partition %d: "

			printk(KERN_NOTICE "Moving partition %d: "

			       "0x%012llx -> 0x%012llx\n", partno,

			       "0x%012llx -> 0x%012llx\n", partno,

			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);

			       (unsigned long long)cur_offset, (unsigned long long)slave->offset);
@@ -567,19 +572,22 @@ static struct mtd_part *allocate_partition(struct mtd_info *master, 
		slave->mtd.erasesize = master->erasesize;

		slave->mtd.erasesize = master->erasesize;

	}

	}





	if ((slave->mtd.flags & MTD_WRITEABLE) &&

	tmp = slave->offset;

	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {

	remainder = do_div(tmp, wr_alignment);

	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {

		/* Doesn't start on a boundary of major erase size */

		/* Doesn't start on a boundary of major erase size */

		/* FIXME: Let it be writable if it is on a boundary of

		/* FIXME: Let it be writable if it is on a boundary of

		 * _minor_ erase size though */

		 * _minor_ erase size though */

		slave->mtd.flags &= ~MTD_WRITEABLE;

		slave->mtd.flags &= ~MTD_WRITEABLE;

		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",

		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",

			part->name);

			part->name);

	}

	}

	if ((slave->mtd.flags & MTD_WRITEABLE) &&



	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {

	tmp = slave->mtd.size;

	remainder = do_div(tmp, wr_alignment);

	if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {

		slave->mtd.flags &= ~MTD_WRITEABLE;

		slave->mtd.flags &= ~MTD_WRITEABLE;

		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",

		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",

			part->name);

			part->name);

	}

	}