diff options
Diffstat (limited to 'drivers/mtd/mtdconcat.c')
| -rw-r--r-- | drivers/mtd/mtdconcat.c | 897 |
1 files changed, 897 insertions, 0 deletions
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c new file mode 100644 index 0000000..8f66d09 --- /dev/null +++ b/drivers/mtd/mtdconcat.c @@ -0,0 +1,897 @@ +/* + * MTD device concatenation layer + * + * (C) 2002 Robert Kaiser <rkaiser@sysgo.de> + * + * NAND support by Christian Gan <cgan@iders.ca> + * + * This code is GPL + * + * $Id: mtdconcat.c,v 1.9 2004/06/30 15:17:41 dbrown 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, offset = 0; + 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 + */ + if ((instr->addr + instr->len) & (erase_regions[i].erasesize - + 1)) + return -EINVAL; + } + + instr->fail_addr = 0xffffffff; + + /* make a local copy of instr to avoid modifying the caller's struct */ + erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL); + + if (!erase) + return -ENOMEM; + + *erase = *instr; + length = instr->len; + + /* + * find the subdevice where the to-be-erased area begins, adjust + * starting offset to be relative to the subdevice start + */ + for (i = 0; i < concat->num_subdev; i++) { + subdev = concat->subdev[i]; + if (subdev->size <= erase->addr) { + erase->addr -= subdev->size; + offset += subdev->size; + } else { + break; + } + } + + /* must never happen since size limit has been verified above */ + if (i >= concat->num_subdev) + BUG(); + + /* now do the erase: */ + err = 0; + for (; length > 0; i++) { + /* loop for all subdevices affected by this request */ + subdev = concat->subdev[i]; /* get current subdevice */ + + /* limit length to subdevice's size: */ + if (erase->addr + length > subdev->size) + erase->len = subdev->size - erase->addr; + else + erase->len = length; + + if (!(subdev->flags & MTD_WRITEABLE)) { + err = -EROFS; + break; + } + length -= erase->len; + if ((err = concat_dev_erase(subdev, erase))) { + /* sanity check: should never happen since + * block alignment has been checked above */ + if (err == -EINVAL) + BUG(); + if (erase->fail_addr != 0xffffffff) + instr->fail_addr = erase->fail_addr + offset; + break; + } + /* + * erase->addr specifies the offset of the area to be + * erased *within the current subdevice*. It can be + * non-zero only the first time through this loop, i.e. + * for the first subdevice where blocks need to be erased. + * All the following erases must begin at the start of the + * current subdevice, i.e. at offset zero. + */ + erase->addr = 0; + offset += subdev->size; + } + instr->state = erase->state; + kfree(erase); + if (err) + return err; + + if (instr->callback) + instr->callback(instr); + return 0; +} + +static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, err = -EINVAL; + + if ((len + ofs) > mtd->size) + return -EINVAL; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + size_t size; + + if (ofs >= subdev->size) { + size = 0; + ofs -= subdev->size; + continue; + } + if (ofs + len > subdev->size) + size = subdev->size - ofs; + else + size = len; + + err = subdev->lock(subdev, ofs, size); + + if (err) + break; + + len -= size; + if (len == 0) + break; + + err = -EINVAL; + ofs = 0; + } + + return err; +} + +static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, err = 0; + + if ((len + ofs) > mtd->size) + return -EINVAL; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + size_t size; + + if (ofs >= subdev->size) { + size = 0; + ofs -= subdev->size; + continue; + } + if (ofs + len > subdev->size) + size = subdev->size - ofs; + else + size = len; + + err = subdev->unlock(subdev, ofs, size); + + if (err) + break; + + len -= size; + if (len == 0) + break; + + err = -EINVAL; + ofs = 0; + } + + return err; +} + +static void concat_sync(struct mtd_info *mtd) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + subdev->sync(subdev); + } +} + +static int concat_suspend(struct mtd_info *mtd) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, rc = 0; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + if ((rc = subdev->suspend(subdev)) < 0) + return rc; + } + return rc; +} + +static void concat_resume(struct mtd_info *mtd) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + subdev->resume(subdev); + } +} + +/* + * This function constructs a virtual MTD device by concatenating + * num_devs MTD devices. A pointer to the new device object is + * stored to *new_dev upon success. This function does _not_ + * register any devices: this is the caller's responsibility. + */ +struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */ + int num_devs, /* number of subdevices */ + char *name) +{ /* name for the new device */ + int i; + size_t size; + struct mtd_concat *concat; + u_int32_t max_erasesize, curr_erasesize; + int num_erase_region; + + printk(KERN_NOTICE "Concatenating MTD devices:\n"); + for (i = 0; i < num_devs; i++) + printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name); + printk(KERN_NOTICE "into device \"%s\"\n", name); + + /* allocate the device structure */ + size = SIZEOF_STRUCT_MTD_CONCAT(num_devs); + concat = kmalloc(size, GFP_KERNEL); + if (!concat) { + printk + ("memory allocation error while creating concatenated device \"%s\"\n", + name); + return NULL; + } + memset(concat, 0, size); + concat->subdev = (struct mtd_info **) (concat + 1); + + /* + * Set up the new "super" device's MTD object structure, check for + * incompatibilites between the subdevices. + */ + concat->mtd.type = subdev[0]->type; + concat->mtd.flags = subdev[0]->flags; + concat->mtd.size = subdev[0]->size; + concat->mtd.erasesize = subdev[0]->erasesize; + concat->mtd.oobblock = subdev[0]->oobblock; + concat->mtd.oobsize = subdev[0]->oobsize; + concat->mtd.ecctype = subdev[0]->ecctype; + concat->mtd.eccsize = subdev[0]->eccsize; + if (subdev[0]->read_ecc) + concat->mtd.read_ecc = concat_read_ecc; + if (subdev[0]->write_ecc) + concat->mtd.write_ecc = concat_write_ecc; + if (subdev[0]->read_oob) + concat->mtd.read_oob = concat_read_oob; + if (subdev[0]->write_oob) + concat->mtd.write_oob = concat_write_oob; + + concat->subdev[0] = subdev[0]; + + for (i = 1; i < num_devs; i++) { + if (concat->mtd.type != subdev[i]->type) { + kfree(concat); + printk("Incompatible device type on \"%s\"\n", + subdev[i]->name); + return NULL; + } + if (concat->mtd.flags != subdev[i]->flags) { + /* + * Expect all flags except MTD_WRITEABLE to be + * equal on all subdevices. + */ + if ((concat->mtd.flags ^ subdev[i]-> + flags) & ~MTD_WRITEABLE) { + kfree(concat); + printk("Incompatible device flags on \"%s\"\n", + subdev[i]->name); + return NULL; + } else + /* if writeable attribute differs, + make super device writeable */ + concat->mtd.flags |= + subdev[i]->flags & MTD_WRITEABLE; + } + concat->mtd.size += subdev[i]->size; + if (concat->mtd.oobblock != subdev[i]->oobblock || + concat->mtd.oobsize != subdev[i]->oobsize || + concat->mtd.ecctype != subdev[i]->ecctype || + concat->mtd.eccsize != subdev[i]->eccsize || + !concat->mtd.read_ecc != !subdev[i]->read_ecc || + !concat->mtd.write_ecc != !subdev[i]->write_ecc || + !concat->mtd.read_oob != !subdev[i]->read_oob || + !concat->mtd.write_oob != !subdev[i]->write_oob) { + kfree(concat); + printk("Incompatible OOB or ECC data on \"%s\"\n", + subdev[i]->name); + return NULL; + } + concat->subdev[i] = subdev[i]; + + } + + concat->num_subdev = num_devs; + concat->mtd.name = name; + + /* + * NOTE: for now, we do not provide any readv()/writev() methods + * because they are messy to implement and they are not + * used to a great extent anyway. + */ + concat->mtd.erase = concat_erase; + concat->mtd.read = concat_read; + concat->mtd.write = concat_write; + concat->mtd.sync = concat_sync; + concat->mtd.lock = concat_lock; + concat->mtd.unlock = concat_unlock; + concat->mtd.suspend = concat_suspend; + concat->mtd.resume = concat_resume; + + /* + * Combine the erase block size info of the subdevices: + * + * first, walk the map of the new device and see how + * many changes in erase size we have + */ + max_erasesize = curr_erasesize = subdev[0]->erasesize; + num_erase_region = 1; + for (i = 0; i < num_devs; i++) { + if (subdev[i]->numeraseregions == 0) { + /* current subdevice has uniform erase size */ + if (subdev[i]->erasesize != curr_erasesize) { + /* if it differs from the last subdevice's erase size, count it */ + ++num_erase_region; + curr_erasesize = subdev[i]->erasesize; + if (curr_erasesize > max_erasesize) + max_erasesize = curr_erasesize; + } + } else { + /* current subdevice has variable erase size */ + int j; + for (j = 0; j < subdev[i]->numeraseregions; j++) { + + /* walk the list of erase regions, count any changes */ + if (subdev[i]->eraseregions[j].erasesize != + curr_erasesize) { + ++num_erase_region; + curr_erasesize = + subdev[i]->eraseregions[j]. + erasesize; + if (curr_erasesize > max_erasesize) + max_erasesize = curr_erasesize; + } + } + } + } + + if (num_erase_region == 1) { + /* + * All subdevices have the same uniform erase size. + * This is easy: + */ + concat->mtd.erasesize = curr_erasesize; + concat->mtd.numeraseregions = 0; + } else { + /* + * erase block size varies across the subdevices: allocate + * space to store the data describing the variable erase regions + */ + struct mtd_erase_region_info *erase_region_p; + u_int32_t begin, position; + + concat->mtd.erasesize = max_erasesize; + concat->mtd.numeraseregions = num_erase_region; + concat->mtd.eraseregions = erase_region_p = + kmalloc(num_erase_region * + sizeof (struct mtd_erase_region_info), GFP_KERNEL); + if (!erase_region_p) { + kfree(concat); + printk + ("memory allocation error while creating erase region list" + " for device \"%s\"\n", name); + return NULL; + } + + /* + * walk the map of the new device once more and fill in + * in erase region info: + */ + curr_erasesize = subdev[0]->erasesize; + begin = position = 0; + for (i = 0; i < num_devs; i++) { + if (subdev[i]->numeraseregions == 0) { + /* current subdevice has uniform erase size */ + if (subdev[i]->erasesize != curr_erasesize) { + /* + * fill in an mtd_erase_region_info structure for the area + * we have walked so far: + */ + erase_region_p->offset = begin; + erase_region_p->erasesize = + curr_erasesize; + erase_region_p->numblocks = + (position - begin) / curr_erasesize; + begin = position; + + curr_erasesize = subdev[i]->erasesize; + ++erase_region_p; + } + position += subdev[i]->size; + } else { + /* current subdevice has variable erase size */ + int j; + for (j = 0; j < subdev[i]->numeraseregions; j++) { + /* walk the list of erase regions, count any changes */ + if (subdev[i]->eraseregions[j]. + erasesize != curr_erasesize) { + erase_region_p->offset = begin; + erase_region_p->erasesize = + curr_erasesize; + erase_region_p->numblocks = + (position - + begin) / curr_erasesize; + begin = position; + + curr_erasesize = + subdev[i]->eraseregions[j]. + erasesize; + ++erase_region_p; + } + position += + subdev[i]->eraseregions[j]. + numblocks * curr_erasesize; + } + } + } + /* Now write the final entry */ + erase_region_p->offset = begin; + erase_region_p->erasesize = curr_erasesize; + erase_region_p->numblocks = (position - begin) / curr_erasesize; + } + + return &concat->mtd; +} + +/* + * This function destroys an MTD object obtained from concat_mtd_devs() + */ + +void mtd_concat_destroy(struct mtd_info *mtd) +{ + struct mtd_concat *concat = CONCAT(mtd); + if (concat->mtd.numeraseregions) + kfree(concat->mtd.eraseregions); + kfree(concat); +} + +EXPORT_SYMBOL(mtd_concat_create); +EXPORT_SYMBOL(mtd_concat_destroy); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>"); +MODULE_DESCRIPTION("Generic support for concatenating of MTD devices"); |