MTD: Add MTD paritioning infrastructure

This MTD part infrastructure will be used by the upcoming
UBI support.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Stefan Roese <sr@denx.de>

3 files changed, 679 insertions, 0 deletions

diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
index 6538f7a..d225a68 100644
--- a/drivers/mtd/Makefile
+++ b/drivers/mtd/Makefile
@@ -25,6 +25,7 @@ include $(TOPDIR)/config.mk
 
 LIB	:= $(obj)libmtd.a
 
+COBJS-$(CONFIG_CMD_UBI) += mtdcore.o mtdpart.o
 COBJS-$(CONFIG_HAS_DATAFLASH) += at45.o
 COBJS-$(CONFIG_FLASH_CFI_DRIVER) += cfi_flash.o
 COBJS-$(CONFIG_HAS_DATAFLASH) += dataflash.o
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
new file mode 100644
index 0000000..64bd7d4
--- /dev/null
+++ b/drivers/mtd/mtdcore.c
@@ -0,0 +1,146 @@
+/*
+ * Core registration and callback routines for MTD
+ * drivers and users.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/compat.h>
+#include <ubi_uboot.h>
+
+struct mtd_info *mtd_table[MAX_MTD_DEVICES];
+
+int add_mtd_device(struct mtd_info *mtd)
+{
+	int i;
+
+	BUG_ON(mtd->writesize == 0);
+
+	for (i = 0; i < MAX_MTD_DEVICES; i++)
+		if (!mtd_table[i]) {
+			mtd_table[i] = mtd;
+			mtd->index = i;
+			mtd->usecount = 0;
+
+			printf("mtd: Giving out device %d to %s\n",
+				i, mtd->name);
+			/* No need to get a refcount on the module containing
+			   the notifier, since we hold the mtd_table_mutex */
+
+			/* We _know_ we aren't being removed, because
+			   our caller is still holding us here. So none
+			   of this try_ nonsense, and no bitching about it
+			   either. :) */
+			return 0;
+		}
+
+	return 1;
+}
+
+/**
+ *      del_mtd_device - unregister an MTD device
+ *      @mtd: pointer to MTD device info structure
+ *
+ *      Remove a device from the list of MTD devices present in the system,
+ *      and notify each currently active MTD 'user' of its departure.
+ *      Returns zero on success or 1 on failure, which currently will happen
+ *      if the requested device does not appear to be present in the list.
+ */
+int del_mtd_device(struct mtd_info *mtd)
+{
+	int ret;
+
+	if (mtd_table[mtd->index] != mtd) {
+		ret = -ENODEV;
+	} else if (mtd->usecount) {
+		printk(KERN_NOTICE "Removing MTD device #%d (%s)"
+				" with use count %d\n",
+				mtd->index, mtd->name, mtd->usecount);
+		ret = -EBUSY;
+	} else {
+		/* No need to get a refcount on the module containing
+		 * the notifier, since we hold the mtd_table_mutex */
+		mtd_table[mtd->index] = NULL;
+
+		ret = 0;
+	}
+
+	return ret;
+}
+
+/**
+ *	get_mtd_device - obtain a validated handle for an MTD device
+ *	@mtd: last known address of the required MTD device
+ *	@num: internal device number of the required MTD device
+ *
+ *	Given a number and NULL address, return the num'th entry in the device
+ *      table, if any.  Given an address and num == -1, search the device table
+ *      for a device with that address and return if it's still present. Given
+ *      both, return the num'th driver only if its address matches. Return
+ *      error code if not.
+ */
+struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
+{
+	struct mtd_info *ret = NULL;
+	int i, err = -ENODEV;
+
+	if (num == -1) {
+		for (i = 0; i < MAX_MTD_DEVICES; i++)
+			if (mtd_table[i] == mtd)
+				ret = mtd_table[i];
+	} else if (num < MAX_MTD_DEVICES) {
+		ret = mtd_table[num];
+		if (mtd && mtd != ret)
+			ret = NULL;
+	}
+
+	if (!ret)
+		goto out_unlock;
+
+	ret->usecount++;
+	return ret;
+
+out_unlock:
+	return ERR_PTR(err);
+}
+
+/**
+ *      get_mtd_device_nm - obtain a validated handle for an MTD device by
+ *      device name
+ *      @name: MTD device name to open
+ *
+ *      This function returns MTD device description structure in case of
+ *      success and an error code in case of failure.
+ */
+struct mtd_info *get_mtd_device_nm(const char *name)
+{
+	int i, err = -ENODEV;
+	struct mtd_info *mtd = NULL;
+
+	for (i = 0; i < MAX_MTD_DEVICES; i++) {
+		if (mtd_table[i] && !strcmp(name, mtd_table[i]->name)) {
+			mtd = mtd_table[i];
+			break;
+		}
+	}
+
+	if (!mtd)
+		goto out_unlock;
+
+	mtd->usecount++;
+	return mtd;
+
+out_unlock:
+	return ERR_PTR(err);
+}
+
+void put_mtd_device(struct mtd_info *mtd)
+{
+	int c;
+
+	c = --mtd->usecount;
+	BUG_ON(c < 0);
+}
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
new file mode 100644
index 0000000..9a3bf6f
--- /dev/null
+++ b/drivers/mtd/mtdpart.c
@@ -0,0 +1,532 @@
+/*
+ * Simple MTD partitioning layer
+ *
+ * (C) 2000 Nicolas Pitre <nico@cam.org>
+ *
+ * This code is GPL
+ *
+ * 	02-21-2002	Thomas Gleixner <gleixner@autronix.de>
+ *			added support for read_oob, write_oob
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <asm/errno.h>
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/compat.h>
+
+/* Our partition linked list */
+static LIST_HEAD(mtd_partitions);
+
+/* Our partition node structure */
+struct mtd_part {
+	struct mtd_info mtd;
+	struct mtd_info *master;
+	u_int32_t offset;
+	int index;
+	struct list_head list;
+	int registered;
+};
+
+/*
+ * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
+ * the pointer to that structure with this macro.
+ */
+#define PART(x)  ((struct mtd_part *)(x))
+
+
+/*
+ * MTD methods which simply translate the effective address and pass through
+ * to the _real_ device.
+ */
+
+static int part_read (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (from >= mtd->size)
+		len = 0;
+	else if (from + len > mtd->size)
+		len = mtd->size - from;
+	res = part->master->read (part->master, from + part->offset,
+				   len, retlen, buf);
+	if (unlikely(res)) {
+		if (res == -EUCLEAN)
+			mtd->ecc_stats.corrected++;
+		if (res == -EBADMSG)
+			mtd->ecc_stats.failed++;
+	}
+	return res;
+}
+
+#ifdef MTD_LINUX
+static int part_point (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys)
+{
+	struct mtd_part *part = PART(mtd);
+	if (from >= mtd->size)
+		len = 0;
+	else if (from + len > mtd->size)
+		len = mtd->size - from;
+	return part->master->point (part->master, from + part->offset,
+				    len, retlen, virt, phys);
+}
+
+static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+
+	part->master->unpoint(part->master, from + part->offset, len);
+}
+#endif
+
+static int part_read_oob(struct mtd_info *mtd, loff_t from,
+			 struct mtd_oob_ops *ops)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (from >= mtd->size)
+		return -EINVAL;
+	if (ops->datbuf && from + ops->len > mtd->size)
+		return -EINVAL;
+	res = part->master->read_oob(part->master, from + part->offset, ops);
+
+	if (unlikely(res)) {
+		if (res == -EUCLEAN)
+			mtd->ecc_stats.corrected++;
+		if (res == -EBADMSG)
+			mtd->ecc_stats.failed++;
+	}
+	return res;
+}
+
+static int part_read_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->read_user_prot_reg (part->master, from,
+					len, retlen, buf);
+}
+
+static int part_get_user_prot_info (struct mtd_info *mtd,
+				    struct otp_info *buf, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->get_user_prot_info (part->master, buf, len);
+}
+
+static int part_read_fact_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->read_fact_prot_reg (part->master, from,
+					len, retlen, buf);
+}
+
+static int part_get_fact_prot_info (struct mtd_info *mtd,
+				    struct otp_info *buf, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->get_fact_prot_info (part->master, buf, len);
+}
+
+static int part_write (struct mtd_info *mtd, loff_t to, size_t len,
+			size_t *retlen, const u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (to >= mtd->size)
+		len = 0;
+	else if (to + len > mtd->size)
+		len = mtd->size - to;
+	return part->master->write (part->master, to + part->offset,
+				    len, retlen, buf);
+}
+
+#ifdef MTD_LINUX
+static int part_panic_write (struct mtd_info *mtd, loff_t to, size_t len,
+			size_t *retlen, const u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (to >= mtd->size)
+		len = 0;
+	else if (to + len > mtd->size)
+		len = mtd->size - to;
+	return part->master->panic_write (part->master, to + part->offset,
+				    len, retlen, buf);
+}
+#endif
+
+static int part_write_oob(struct mtd_info *mtd, loff_t to,
+			 struct mtd_oob_ops *ops)
+{
+	struct mtd_part *part = PART(mtd);
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+
+	if (to >= mtd->size)
+		return -EINVAL;
+	if (ops->datbuf && to + ops->len > mtd->size)
+		return -EINVAL;
+	return part->master->write_oob(part->master, to + part->offset, ops);
+}
+
+static int part_write_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->write_user_prot_reg (part->master, from,
+					len, retlen, buf);
+}
+
+static int part_lock_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->lock_user_prot_reg (part->master, from, len);
+}
+
+#ifdef MTD_LINUX
+static int part_writev (struct mtd_info *mtd,  const struct kvec *vecs,
+			 unsigned long count, loff_t to, size_t *retlen)
+{
+	struct mtd_part *part = PART(mtd);
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	return part->master->writev (part->master, vecs, count,
+					to + part->offset, retlen);
+}
+#endif
+
+static int part_erase (struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mtd_part *part = PART(mtd);
+	int ret;
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (instr->addr >= mtd->size)
+		return -EINVAL;
+	instr->addr += part->offset;
+	ret = part->master->erase(part->master, instr);
+	if (ret) {
+		if (instr->fail_addr != 0xffffffff)
+			instr->fail_addr -= part->offset;
+		instr->addr -= part->offset;
+	}
+	return ret;
+}
+
+void mtd_erase_callback(struct erase_info *instr)
+{
+	if (instr->mtd->erase == part_erase) {
+		struct mtd_part *part = PART(instr->mtd);
+
+		if (instr->fail_addr != 0xffffffff)
+			instr->fail_addr -= part->offset;
+		instr->addr -= part->offset;
+	}
+	if (instr->callback)
+		instr->callback(instr);
+}
+#ifdef MTD_LINUX
+EXPORT_SYMBOL_GPL(mtd_erase_callback);
+#endif
+
+#ifdef MTD_LINUX
+static int part_lock (struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	if ((len + ofs) > mtd->size)
+		return -EINVAL;
+	return part->master->lock(part->master, ofs + part->offset, len);
+}
+
+static int part_unlock (struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+	struct mtd_part *part = PART(mtd);
+	if ((len + ofs) > mtd->size)
+		return -EINVAL;
+	return part->master->unlock(part->master, ofs + part->offset, len);
+}
+#endif
+
+static void part_sync(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+	part->master->sync(part->master);
+}
+
+#ifdef MTD_LINUX
+static int part_suspend(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+	return part->master->suspend(part->master);
+}
+
+static void part_resume(struct mtd_info *mtd)
+{
+	struct mtd_part *part = PART(mtd);
+	part->master->resume(part->master);
+}
+#endif
+
+static int part_block_isbad (struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	if (ofs >= mtd->size)
+		return -EINVAL;
+	ofs += part->offset;
+	return part->master->block_isbad(part->master, ofs);
+}
+
+static int part_block_markbad (struct mtd_info *mtd, loff_t ofs)
+{
+	struct mtd_part *part = PART(mtd);
+	int res;
+
+	if (!(mtd->flags & MTD_WRITEABLE))
+		return -EROFS;
+	if (ofs >= mtd->size)
+		return -EINVAL;
+	ofs += part->offset;
+	res = part->master->block_markbad(part->master, ofs);
+#ifdef MTD_LINUX
+	if (!res)
+		mtd->ecc_stats.badblocks++;
+#endif
+	return res;
+}
+
+/*
+ * This function unregisters and destroy all slave MTD objects which are
+ * attached to the given master MTD object.
+ */
+
+int del_mtd_partitions(struct mtd_info *master)
+{
+	struct list_head *node;
+	struct mtd_part *slave;
+
+	for (node = mtd_partitions.next;
+	     node != &mtd_partitions;
+	     node = node->next) {
+		slave = list_entry(node, struct mtd_part, list);
+		if (slave->master == master) {
+			struct list_head *prev = node->prev;
+			__list_del(prev, node->next);
+			if(slave->registered)
+				del_mtd_device(&slave->mtd);
+			kfree(slave);
+			node = prev;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * This function, given a master MTD object and a partition table, creates
+ * and registers slave MTD objects which are bound to the master according to
+ * the partition definitions.
+ * (Q: should we register the master MTD object as well?)
+ */
+
+int add_mtd_partitions(struct mtd_info *master,
+		       const struct mtd_partition *parts,
+		       int nbparts)
+{
+	struct mtd_part *slave;
+	u_int32_t cur_offset = 0;
+	int i;
+
+	printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
+
+	for (i = 0; i < nbparts; i++) {
+
+		/* allocate the partition structure */
+		slave = kzalloc (sizeof(*slave), GFP_KERNEL);
+		if (!slave) {
+			printk ("memory allocation error while creating partitions for \"%s\"\n",
+				master->name);
+			del_mtd_partitions(master);
+			return -ENOMEM;
+		}
+		list_add(&slave->list, &mtd_partitions);
+
+		/* set up the MTD object for this partition */
+		slave->mtd.type = master->type;
+		slave->mtd.flags = master->flags & ~parts[i].mask_flags;
+		slave->mtd.size = parts[i].size;
+		slave->mtd.writesize = master->writesize;
+		slave->mtd.oobsize = master->oobsize;
+		slave->mtd.oobavail = master->oobavail;
+		slave->mtd.subpage_sft = master->subpage_sft;
+
+		slave->mtd.name = parts[i].name;
+		slave->mtd.owner = master->owner;
+
+		slave->mtd.read = part_read;
+		slave->mtd.write = part_write;
+
+#ifdef MTD_LINUX
+		if (master->panic_write)
+			slave->mtd.panic_write = part_panic_write;
+
+		if(master->point && master->unpoint){
+			slave->mtd.point = part_point;
+			slave->mtd.unpoint = part_unpoint;
+		}
+#endif
+
+		if (master->read_oob)
+			slave->mtd.read_oob = part_read_oob;
+		if (master->write_oob)
+			slave->mtd.write_oob = part_write_oob;
+		if(master->read_user_prot_reg)
+			slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
+		if(master->read_fact_prot_reg)
+			slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
+		if(master->write_user_prot_reg)
+			slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
+		if(master->lock_user_prot_reg)
+			slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
+		if(master->get_user_prot_info)
+			slave->mtd.get_user_prot_info = part_get_user_prot_info;
+		if(master->get_fact_prot_info)
+			slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
+		if (master->sync)
+			slave->mtd.sync = part_sync;
+#ifdef MTD_LINUX
+		if (!i && master->suspend && master->resume) {
+				slave->mtd.suspend = part_suspend;
+				slave->mtd.resume = part_resume;
+		}
+		if (master->writev)
+			slave->mtd.writev = part_writev;
+		if (master->lock)
+			slave->mtd.lock = part_lock;
+		if (master->unlock)
+			slave->mtd.unlock = part_unlock;
+#endif
+		if (master->block_isbad)
+			slave->mtd.block_isbad = part_block_isbad;
+		if (master->block_markbad)
+			slave->mtd.block_markbad = part_block_markbad;
+		slave->mtd.erase = part_erase;
+		slave->master = master;
+		slave->offset = parts[i].offset;
+		slave->index = i;
+
+		if (slave->offset == MTDPART_OFS_APPEND)
+			slave->offset = cur_offset;
+		if (slave->offset == MTDPART_OFS_NXTBLK) {
+			slave->offset = cur_offset;
+			if ((cur_offset % master->erasesize) != 0) {
+				/* Round up to next erasesize */
+				slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
+				printk(KERN_NOTICE "Moving partition %d: "
+				       "0x%08x -> 0x%08x\n", i,
+				       cur_offset, slave->offset);
+			}
+		}
+		if (slave->mtd.size == MTDPART_SIZ_FULL)
+			slave->mtd.size = master->size - slave->offset;
+		cur_offset = slave->offset + slave->mtd.size;
+
+		printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
+			slave->offset + slave->mtd.size, slave->mtd.name);
+
+		/* let's do some sanity checks */
+		if (slave->offset >= master->size) {
+				/* let's register it anyway to preserve ordering */
+			slave->offset = 0;
+			slave->mtd.size = 0;
+			printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
+				parts[i].name);
+		}
+		if (slave->offset + slave->mtd.size > master->size) {
+			slave->mtd.size = master->size - slave->offset;
+			printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
+				parts[i].name, master->name, slave->mtd.size);
+		}
+		if (master->numeraseregions>1) {
+			/* Deal with variable erase size stuff */
+			int i;
+			struct mtd_erase_region_info *regions = master->eraseregions;
+
+			/* Find the first erase regions which is part of this partition. */
+			for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
+				;
+
+			for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
+				if (slave->mtd.erasesize < regions[i].erasesize) {
+					slave->mtd.erasesize = regions[i].erasesize;
+				}
+			}
+		} else {
+			/* Single erase size */
+			slave->mtd.erasesize = master->erasesize;
+		}
+
+		if ((slave->mtd.flags & MTD_WRITEABLE) &&
+		    (slave->offset % slave->mtd.erasesize)) {
+			/* Doesn't start on a boundary of major erase size */
+			/* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
+			slave->mtd.flags &= ~MTD_WRITEABLE;
+			printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
+				parts[i].name);
+		}
+		if ((slave->mtd.flags & MTD_WRITEABLE) &&
+		    (slave->mtd.size % slave->mtd.erasesize)) {
+			slave->mtd.flags &= ~MTD_WRITEABLE;
+			printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
+				parts[i].name);
+		}
+
+		slave->mtd.ecclayout = master->ecclayout;
+		if (master->block_isbad) {
+			uint32_t offs = 0;
+
+			while(offs < slave->mtd.size) {
+				if (master->block_isbad(master,
+							offs + slave->offset))
+					slave->mtd.ecc_stats.badblocks++;
+				offs += slave->mtd.erasesize;
+			}
+		}
+
+#ifdef MTD_LINUX
+		if (parts[i].mtdp) {
+			/* store the object pointer
+			 * (caller may or may not register it */
+			*parts[i].mtdp = &slave->mtd;
+			slave->registered = 0;
+		} else {
+			/* register our partition */
+			add_mtd_device(&slave->mtd);
+			slave->registered = 1;
+		}
+#else
+		/* register our partition */
+		add_mtd_device(&slave->mtd);
+		slave->registered = 1;
+#endif
+	}
+
+	return 0;
+}
+
+#ifdef MTD_LINUX
+EXPORT_SYMBOL(add_mtd_partitions);
+EXPORT_SYMBOL(del_mtd_partitions);
+#endif