path: root/drivers/mtd/inftlcore.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
 *
 * Copyright © 2002, Greg Ungerer (gerg@snapgear.com)
 *
 * Based heavily on the nftlcore.c code which is:
 * Copyright © 1999 Machine Vision Holdings, Inc.
 * Copyright © 1999 David Woodhouse <dwmw2@infradead.org>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/hdreg.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nftl.h>
#include <linux/mtd/inftl.h>
#include <linux/mtd/rawnand.h>
#include <linux/uaccess.h>
#include <asm/errno.h>
#include <asm/io.h>

/*
 * Maximum number of loops while examining next block, to have a
 * chance to detect consistency problems (they should never happen
 * because of the checks done in the mounting.
 */
#define MAX_LOOPS 10000

static void inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
	struct INFTLrecord *inftl;
	unsigned long temp;

	if (!mtd_type_is_nand(mtd) || mtd->size > UINT_MAX)
		return;
	/* OK, this is moderately ugly.  But probably safe.  Alternatives? */
	if (memcmp(mtd->name, "DiskOnChip", 10))
		return;

	if (!mtd->_block_isbad) {
		printk(KERN_ERR
"INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
"Please use the new diskonchip driver under the NAND subsystem.\n");
		return;
	}

	pr_debug("INFTL: add_mtd for %s\n", mtd->name);

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

	if (!inftl)
		return;

	inftl->mbd.mtd = mtd;
	inftl->mbd.devnum = -1;

	inftl->mbd.tr = tr;

	if (INFTL_mount(inftl) < 0) {
		printk(KERN_WARNING "INFTL: could not mount device\n");
		kfree(inftl);
		return;
	}

	/* OK, it's a new one. Set up all the data structures. */

	/* Calculate geometry */
	inftl->cylinders = 1024;
	inftl->heads = 16;

	temp = inftl->cylinders * inftl->heads;
	inftl->sectors = inftl->mbd.size / temp;
	if (inftl->mbd.size % temp) {
		inftl->sectors++;
		temp = inftl->cylinders * inftl->sectors;
		inftl->heads = inftl->mbd.size / temp;

		if (inftl->mbd.size % temp) {
			inftl->heads++;
			temp = inftl->heads * inftl->sectors;
			inftl->cylinders = inftl->mbd.size / temp;
		}
	}

	if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
		/*
		  Oh no we don't have
		   mbd.size == heads * cylinders * sectors
		*/
		printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
		       "match size of 0x%lx.\n", inftl->mbd.size);
		printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
			"(== 0x%lx sects)\n",
			inftl->cylinders, inftl->heads , inftl->sectors,
			(long)inftl->cylinders * (long)inftl->heads *
			(long)inftl->sectors );
	}

	if (add_mtd_blktrans_dev(&inftl->mbd)) {
		kfree(inftl->PUtable);
		kfree(inftl->VUtable);
		kfree(inftl);
		return;
	}
#ifdef PSYCHO_DEBUG
	printk(KERN_INFO "INFTL: Found new inftl%c\n", inftl->mbd.devnum + 'a');
#endif
	return;
}

static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
{
	struct INFTLrecord *inftl = (void *)dev;

	pr_debug("INFTL: remove_dev (i=%d)\n", dev->devnum);

	del_mtd_blktrans_dev(dev);

	kfree(inftl->PUtable);
	kfree(inftl->VUtable);
}

/*
 * Actual INFTL access routines.
 */

/*
 * Read oob data from flash
 */
int inftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
		   size_t *retlen, uint8_t *buf)
{
	struct mtd_oob_ops ops;
	int res;

	ops.mode = MTD_OPS_PLACE_OOB;
	ops.ooboffs = offs & (mtd->writesize - 1);
	ops.ooblen = len;
	ops.oobbuf = buf;
	ops.datbuf = NULL;

	res = mtd_read_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
	*retlen = ops.oobretlen;
	return res;
}

/*
 * Write oob data to flash
 */
int inftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
		    size_t *retlen, uint8_t *buf)
{
	struct mtd_oob_ops ops;
	int res;

	ops.mode = MTD_OPS_PLACE_OOB;
	ops.ooboffs = offs & (mtd->writesize - 1);
	ops.ooblen = len;
	ops.oobbuf = buf;
	ops.datbuf = NULL;

	res = mtd_write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
	*retlen = ops.oobretlen;
	return res;
}

/*
 * Write data and oob to flash
 */
static int inftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
		       size_t *retlen, uint8_t *buf, uint8_t *oob)
{
	struct mtd_oob_ops ops;
	int res;

	ops.mode = MTD_OPS_PLACE_OOB;
	ops.ooboffs = offs;
	ops.ooblen = mtd->oobsize;
	ops.oobbuf = oob;
	ops.datbuf = buf;
	ops.len = len;

	res = mtd_write_oob(mtd, offs & ~(mtd->writesize - 1), &ops);
	*retlen = ops.retlen;
	return res;
}

/*
 * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
 *	This function is used when the give Virtual Unit Chain.
 */
static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int