mtdconcat.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

/*
 * MTD device concatenation layer
 *
 * (C) 2002 Robert Kaiser <[e-mail]>
 *
 * NAND support by Christian Gan <[e-mail]>
 *
 * This code is GPL
 *
 * $Id: mtdconcat.c,v 1.8 2003/06/30 11:01:26 dwmw2 Exp $
 */

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

#include <linux/mtd/mtd.h>
#include <linux/mtd/concat.h>

/*
 * Our storage structure:
 * Subdev points to an array of pointers to struct mtd_info objects
 * which is allocated along with this structure
 *
 */
struct mtd_concat {
	struct mtd_info mtd;
	int num_subdev;
	struct mtd_info **subdev;
};

/*
 * how to calculate the size required for the above structure,
 * including the pointer array subdev points to:
 */
#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev)	\
	((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))

/*
 * Given a pointer to the MTD object in the mtd_concat structure,
 * we can retrieve the pointer to that structure with this macro.
 */
#define CONCAT(x)  ((struct mtd_concat *)(x))

/* 
 * MTD methods which look up the relevant subdevice, translate the
 * effective address and pass through to the subdevice.
 */

static int
concat_read(struct mtd_info *mtd, loff_t from, size_t len,
	    size_t * retlen, u_char * buf)
{
	struct mtd_concat *concat = CONCAT(mtd);
	int err = -EINVAL;
	int i;

	*retlen = 0;

	for (i = 0; i < concat->num_subdev; i++) {
		struct mtd_info *subdev = concat->subdev[i];
		size_t size, retsize;

		if (from >= subdev->size) {
			/* Not destined for this subdev */
			size = 0;
			from -= subdev->size;
			continue;
		}
		if (from + len > subdev->size)
			/* First part goes into this subdev */
			size = subdev->size - from;
		else
			/* Entire transaction goes into this subdev */
			size = len;

		err = subdev->read(subdev, from, size, &retsize, buf);

		if (err)
			break;

		*retlen += retsize;
		len -= size;
		if (len == 0)
			break;

		err = -EINVAL;
		buf += size;
		from = 0;
	}
	return err;
}

static int
concat_write(struct mtd_info *mtd, loff_t to, size_t len,
	     size_t * retlen, const u_char * buf)
{
	struct mtd_concat *concat = CONCAT(mtd);
	int err = -EINVAL;
	int i;

	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;

	*retlen = 0;

	for (i = 0; i < concat->num_subdev; i++) {
		struct mtd_info *subdev = concat->subdev[i];
		size_t size, retsize;

		if (to >= subdev->size) {
			size = 0;
			to -= subdev->size;
			continue;
		}
		if (to + len > subdev->size)
			size = subdev->size - to;
		else
			size = len;

		if (!(subdev->flags & MTD_WRITEABLE))
			err = -EROFS;
		else
			err = subdev->write(subdev, to, size, &retsize, buf);

		if (err)
			break;

		*retlen += retsize;
		len -= size;
		if (len == 0)
			break;

		err = -EINVAL;
		buf += size;
		to = 0;
	}
	return err;
}

static int
concat_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
		size_t * retlen, u_char * buf, u_char * eccbuf,
		struct nand_oobinfo *oobsel)
{
	struct mtd_concat *concat = CONCAT(mtd);
	int err = -EINVAL;
	int i;

	*retlen = 0;

	for (i = 0; i < concat->num_subdev; i++) {
		struct mtd_info *subdev = concat->subdev[i];
		size_t size, retsize;

		if (from >= subdev->size) {
			/* Not destined for this subdev */
			size = 0;
			from -= subdev->size;
			continue;
		}

		if (from + len > subdev->size)
			/* First part goes into this subdev */
			size = subdev->size - from;
		else
			/* Entire transaction goes into this subdev */
			size = len;

		if (subdev->read_ecc)
			err = subdev->read_ecc(subdev, from, size,
					       &retsize, buf, eccbuf, oobsel);
		else
			err = -EINVAL;

		if (err)
			break;

		*retlen += retsize;
		len -= size;
		if (len == 0)
			break;

		err = -EINVAL;
		buf += size;
		if (eccbuf) {
			eccbuf += subdev->oobsize;
			/* in nand.c at least, eccbufs are
			   tagged with 2 (int)eccstatus'; we
			   must account for these */
			eccbuf += 2 * (sizeof (int));
		}
		from = 0;
	}
	return err;
}

static int
concat_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
		 size_t * retlen, const u_char * buf, u_char * eccbuf,
		 struct nand_oobinfo *oobsel)
{
	struct mtd_concat *concat = CONCAT(mtd);
	int err = -EINVAL;
	int i;

	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;

	*retlen = 0;

	for (i = 0; i < concat->num_subdev; i++) {
		struct mtd_info *subdev = concat->subdev[i];
		size_t size, retsize;

		if (to >= subdev->size) {
			size = 0;
			to -= subdev->size;
			continue;
		}
		if (to + len > subdev->size)
			size = subdev->size - to;
		else
			size = len;

		if (!(subdev->flags & MTD_WRITEABLE))
			err = -EROFS;
		else if (subdev->write_ecc)
			err = subdev->write_ecc(subdev, to, size,
						&retsize, buf, eccbuf, oobsel);
		else
			err = -EINVAL;

		if (err)
			break;

		*retlen += retsize;
		len -= size;
		if (len == 0)
			break;

		err = -EINVAL;
		buf += size;
		if (eccbuf)
			eccbuf += subdev->oobsize;
		to = 0;
	}
	return err;
}

static int
concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
		size_t * retlen, u_char * buf)
{
	struct mtd_concat *concat = CONCAT(mtd);
	int err = -EINVAL;
	int i;

	*retlen = 0;

	for (i = 0; i < concat->num_subdev; i++) {
		struct mtd_info *subdev = concat->subdev[i];
		size_t size, retsize;

		if (from >= subdev->size) {
			/* Not destined for this subdev */
			size = 0;
			from -= subdev->size;
			continue;
		}
		if (from + len > subdev->size)
			/* First part goes into this subdev */
			size = subdev->size - from;
		else
			/* Entire transaction goes into this subdev */
			size = len;

		if (subdev->read_oob)
			err = subdev->read_oob(subdev, from, size,
					       &retsize, buf);
		else
			err = -EINVAL;

		if (err)
			break;

		*retlen += retsize;
		len -= size;
		if (len == 0)
			break;

		err = -EINVAL;
		buf += size;
		from = 0;
	}
	return err;
}

static int
concat_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
		 size_t * retlen, const u_char * buf)
{
	struct mtd_concat *concat = CONCAT(mtd);
	int err = -EINVAL;
	int i;

	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;

	*retlen = 0;

	for (i = 0; i < concat->num_subdev; i++) {
		struct mtd_info *subdev = concat->subdev[i];
		size_t size, retsize;

		if (to >= subdev->size) {
			size = 0;
			to -= subdev->size;
			continue;
		}
		if (to + len > subdev->size)
			size = subdev->size - to;
		else
			size = len;

		if (!(subdev->flags & MTD_WRITEABLE))
			err = -EROFS;
		else if (subdev->write_oob)
			err = subdev->write_oob(subdev, to, size, &retsize,
						buf);
		else
			err = -EINVAL;

		if (err)
			break;

		*retlen += retsize;
		len -= size;
		if (len == 0)
			break;

		err = -EINVAL;
		buf += size;
		to = 0;
	}
	return err;
}

static void concat_erase_callback(struct erase_info *instr)
{
	wake_up((wait_queue_head_t *) instr->priv);
}

static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
{
	int err;
	wait_queue_head_t waitq;
	DECLARE_WAITQUEUE(wait, current);

	/*
	 * This code was stol^H^H^H^Hinspired by mtdchar.c
	 */
	init_waitqueue_head(&waitq);

	erase->mtd = mtd;
	erase->callback = concat_erase_callback;
	erase->priv = (unsigned long) &waitq;

	/*
	 * FIXME: Allow INTERRUPTIBLE. Which means
	 * not having the wait_queue head on the stack.
	 */
	err = mtd->erase(mtd, erase);
	if (!err) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		add_wait_queue(&waitq, &wait);
		if (erase->state != MTD_ERASE_DONE
		    && erase->state != MTD_ERASE_FAILED)
			schedule();
		remove_wait_queue(&waitq, &wait);
		set_current_state(TASK_RUNNING);

		err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
	}
	return err;
}

static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	struct mtd_concat *concat = CONCAT(mtd);
	struct mtd_info *subdev;
	int i, err;
	u_int32_t length;
	struct erase_info *erase;

	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;

	if (instr->addr > concat->mtd.size)
		return -EINVAL;

	if (instr->len + instr->addr > concat->mtd.size)
		return -EINVAL;

	/*
	 * Check for proper erase block alignment of the to-be-erased area.
	 * It is easier to do this based on the super device's erase
	 * region info rather than looking at each particular sub-device
	 * in turn.
	 */
	if (!concat->mtd.numeraseregions) {
		/* the easy case: device has uniform erase block size */
		if (instr->addr & (concat->mtd.erasesize - 1))
			return -EINVAL;
		if (instr->len & (concat->mtd.erasesize - 1))
			return -EINVAL;
	} else {
		/* device has variable erase size */
		struct mtd_erase_region_info *erase_regions =
		    concat->mtd.eraseregions;

		/*
		 * Find the erase region where the to-be-erased area begins:
		 */
		for (i = 0; i < concat->mtd.numeraseregions &&
		     instr->addr >= erase_regions[i].offset; i++) ;
		--i;

		/*
		 * Now erase_regions[i] is the region in which the
		 * to-be-erased area begins. Verify that the starting
		 * offset is aligned to this region's erase size:
		 */
		if (instr->addr & (erase_regions[i].erasesize - 1))
			return -EINVAL;

		/*
		 * now find the erase region where the to-be-erased area ends:
		 */
		for (; i < concat->mtd.numeraseregions &&
		     (instr->addr + instr->len) >= erase_regions[i].offset;
		     ++i) ;
		--i;
		/*
		 * check if the ending offset is aligned to this region's erase size