--- /dev/null
+/*
+ * Simple MTD partitioning layer
+ *
+ * (C) 2000 Nicolas Pitre <nico@cam.org>
+ *
+ * This code is GPL
+ *
+ * $Id: mtdpart.c,v 1.1 2002-05-22 12:38:56 wookey Exp $
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.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;
+};
+
+/*
+ * 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);
+ if (from >= mtd->size)
+ len = 0;
+ else if (from + len > mtd->size)
+ len = mtd->size - from;
+ return part->master->read (part->master, from + part->offset,
+ len, retlen, buf);
+}
+
+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);
+}
+
+static int part_writev (struct mtd_info *mtd, const struct iovec *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);
+}
+
+static int part_readv (struct mtd_info *mtd, struct iovec *vecs,
+ unsigned long count, loff_t from, size_t *retlen)
+{
+ struct mtd_part *part = PART(mtd);
+ return part->master->readv (part->master, vecs, count,
+ from + part->offset, retlen);
+}
+
+static int part_erase (struct mtd_info *mtd, struct erase_info *instr)
+{
+ struct mtd_part *part = PART(mtd);
+ if (!(mtd->flags & MTD_WRITEABLE))
+ return -EROFS;
+ if (instr->addr >= mtd->size)
+ return -EINVAL;
+ instr->addr += part->offset;
+ return part->master->erase(part->master, instr);
+}
+
+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);
+}
+
+static void part_sync(struct mtd_info *mtd)
+{
+ struct mtd_part *part = PART(mtd);
+ part->master->sync(part->master);
+}
+
+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);
+}
+
+/*
+ * 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);
+ 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,
+ 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 = kmalloc (sizeof(*slave), GFP_KERNEL);
+ if (!slave) {
+ printk ("memory allocation error while creating partitions for \"%s\"\n",
+ master->name);
+ del_mtd_partitions(master);
+ return -ENOMEM;
+ }
+ memset(slave, 0, sizeof(*slave));
+ 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.oobblock = master->oobblock;
+ slave->mtd.oobsize = master->oobsize;
+ slave->mtd.ecctype = master->ecctype;
+ slave->mtd.eccsize = master->eccsize;
+
+ slave->mtd.name = parts[i].name;
+ slave->mtd.bank_size = master->bank_size;
+
+ slave->mtd.module = master->module;
+
+ slave->mtd.read = part_read;
+ slave->mtd.write = part_write;
+ if (master->sync)
+ slave->mtd.sync = part_sync;
+ 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->readv)
+ slave->mtd.readv = part_readv;
+ if (master->lock)
+ slave->mtd.lock = part_lock;
+ if (master->unlock)
+ slave->mtd.unlock = part_unlock;
+/* cdhm: fix add oob functions to partitions */
+ if (master->read_oob)
+ slave->mtd.read_oob = master->read_oob;
+ if (master->write_oob)
+ slave->mtd.write_oob = master->write_oob;
+/* cdhm: end of fix */
+ 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->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);
+ }
+
+ /* register our partition */
+ add_mtd_device(&slave->mtd);
+ }
+
+ return 0;
+}
+
+EXPORT_SYMBOL(add_mtd_partitions);
+EXPORT_SYMBOL(del_mtd_partitions);
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
+MODULE_DESCRIPTION("Generic support for partitioning of MTD devices");
+
projects / yaffs / .git / blobdiff