diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/mtd/mtdconcat.c | 872 |
1 files changed, 872 insertions, 0 deletions
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c new file mode 100644 index 000000000..cbc5925e6 --- /dev/null +++ b/drivers/mtd/mtdconcat.c @@ -0,0 +1,872 @@ +/* + * MTD device concatenation layer + * + * Copyright © 2002 Robert Kaiser <rkaiser@sysgo.de> + * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org> + * + * NAND support by Christian Gan <cgan@iders.ca> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/types.h> +#include <linux/backing-dev.h> + +#include <linux/mtd/mtd.h> +#include <linux/mtd/concat.h> + +#include <asm/div64.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 ret = 0, err; + int i; + + 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 = mtd_read(subdev, from, size, &retsize, buf); + + /* Save information about bitflips! */ + if (unlikely(err)) { + if (mtd_is_eccerr(err)) { + mtd->ecc_stats.failed++; + ret = err; + } else if (mtd_is_bitflip(err)) { + mtd->ecc_stats.corrected++; + /* Do not overwrite -EBADMSG !! */ + if (!ret) + ret = err; + } else + return err; + } + + *retlen += retsize; + len -= size; + if (len == 0) + return ret; + + buf += size; + from = 0; + } + return -EINVAL; +} + +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; + + 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; + + err = mtd_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_writev(struct mtd_info *mtd, const struct kvec *vecs, + unsigned long count, loff_t to, size_t * retlen) +{ + struct mtd_concat *concat = CONCAT(mtd); + struct kvec *vecs_copy; + unsigned long entry_low, entry_high; + size_t total_len = 0; + int i; + int err = -EINVAL; + + /* Calculate total length of data */ + for (i = 0; i < count; i++) + total_len += vecs[i].iov_len; + + /* Check alignment */ + if (mtd->writesize > 1) { + uint64_t __to = to; + if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize)) + return -EINVAL; + } + + /* make a copy of vecs */ + vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL); + if (!vecs_copy) + return -ENOMEM; + + entry_low = 0; + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + size_t size, wsize, retsize, old_iov_len; + + if (to >= subdev->size) { + to -= subdev->size; + continue; + } + + size = min_t(uint64_t, total_len, subdev->size - to); + wsize = size; /* store for future use */ + + entry_high = entry_low; + while (entry_high < count) { + if (size <= vecs_copy[entry_high].iov_len) + break; + size -= vecs_copy[entry_high++].iov_len; + } + + old_iov_len = vecs_copy[entry_high].iov_len; + vecs_copy[entry_high].iov_len = size; + + err = mtd_writev(subdev, &vecs_copy[entry_low], + entry_high - entry_low + 1, to, &retsize); + + vecs_copy[entry_high].iov_len = old_iov_len - size; + vecs_copy[entry_high].iov_base += size; + + entry_low = entry_high; + + if (err) + break; + + *retlen += retsize; + total_len -= wsize; + + if (total_len == 0) + break; + + err = -EINVAL; + to = 0; + } + + kfree(vecs_copy); + return err; +} + +static int +concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops) +{ + struct mtd_concat *concat = CONCAT(mtd); + struct mtd_oob_ops devops = *ops; + int i, err, ret = 0; + + ops->retlen = ops->oobretlen = 0; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + + if (from >= subdev->size) { + from -= subdev->size; + continue; + } + + /* partial read ? */ + if (from + devops.len > subdev->size) + devops.len = subdev->size - from; + + err = mtd_read_oob(subdev, from, &devops); + ops->retlen += devops.retlen; + ops->oobretlen += devops.oobretlen; + + /* Save information about bitflips! */ + if (unlikely(err)) { + if (mtd_is_eccerr(err)) { + mtd->ecc_stats.failed++; + ret = err; + } else if (mtd_is_bitflip(err)) { + mtd->ecc_stats.corrected++; + /* Do not overwrite -EBADMSG !! */ + if (!ret) + ret = err; + } else + return err; + } + + if (devops.datbuf) { + devops.len = ops->len - ops->retlen; + if (!devops.len) + return ret; + devops.datbuf += devops.retlen; + } + if (devops.oobbuf) { + devops.ooblen = ops->ooblen - ops->oobretlen; + if (!devops.ooblen) + return ret; + devops.oobbuf += ops->oobretlen; + } + + from = 0; + } + return -EINVAL; +} + +static int +concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops) +{ + struct mtd_concat *concat = CONCAT(mtd); + struct mtd_oob_ops devops = *ops; + int i, err; + + if (!(mtd->flags & MTD_WRITEABLE)) + return -EROFS; + + ops->retlen = ops->oobretlen = 0; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + + if (to >= subdev->size) { + to -= subdev->size; + continue; + } + + /* partial write ? */ + if (to + devops.len > subdev->size) + devops.len = subdev->size - to; + + err = mtd_write_oob(subdev, to, &devops); + ops->retlen += devops.retlen; + ops->oobretlen += devops.oobretlen; + if (err) + return err; + + if (devops.datbuf) { + devops.len = ops->len - ops->retlen; + if (!devops.len) + return 0; + devops.datbuf += devops.retlen; + } + if (devops.oobbuf) { + devops.ooblen = ops->ooblen - ops->oobretlen; + if (!devops.ooblen) + return 0; + devops.oobbuf += devops.oobretlen; + } + to = 0; + } + return -EINVAL; +} + +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; + uint64_t length, offset = 0; + struct erase_info *erase; + + /* + * 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 (i < 0 || 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 (i < 0 || ((instr->addr + instr->len) & + (erase_regions[i].erasesize - 1))) + return -EINVAL; + } + + /* 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 */ + BUG_ON(i >= concat->num_subdev); + + /* 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; + + length -= erase->len; + if ((err = mtd_erase(subdev, erase))) { + /* sanity check: should never happen since + * block alignment has been checked above */ + BUG_ON(err == -EINVAL); + if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN) + 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; + } + kfree(erase); + + return err; +} + +static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, err = -EINVAL; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + uint64_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 = mtd_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, uint64_t len) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, err = 0; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + uint64_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 = mtd_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]; + mtd_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 = mtd_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]; + mtd_resume(subdev); + } +} + +static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, res = 0; + + if (!mtd_can_have_bb(concat->subdev[0])) + return res; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + + if (ofs >= subdev->size) { + ofs -= subdev->size; + continue; + } + + res = mtd_block_isbad(subdev, ofs); + break; + } + + return res; +} + +static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs) +{ + struct mtd_concat *concat = CONCAT(mtd); + int i, err = -EINVAL; + + for (i = 0; i < concat->num_subdev; i++) { + struct mtd_info *subdev = concat->subdev[i]; + + if (ofs >= subdev->size) { + ofs -= subdev->size; + continue; + } + + err = mtd_block_markbad(subdev, ofs); + if (!err) + mtd->ecc_stats.badblocks++; + break; + } + + return err; +} + +/* + * 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 */ + const char *name) +{ /* name for the new device */ + int i; + size_t size; + struct mtd_concat *concat; + uint32_t max_erasesize, curr_erasesize; + int num_erase_region; + int max_writebufsize = 0; + + 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 = kzalloc(size, GFP_KERNEL); + if (!concat) { + printk + ("memory allocation error while creating concatenated device \"%s\"\n", + name); + return NULL; + } + concat->subdev = (struct mtd_info **) (concat + 1); + + /* + * Set up the new "super" device's MTD object structure, check for + * incompatibilities 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.writesize = subdev[0]->writesize; + + for (i = 0; i < num_devs; i++) + if (max_writebufsize < subdev[i]->writebufsize) + max_writebufsize = subdev[i]->writebufsize; + concat->mtd.writebufsize = max_writebufsize; + + concat->mtd.subpage_sft = subdev[0]->subpage_sft; + concat->mtd.oobsize = subdev[0]->oobsize; + concat->mtd.oobavail = subdev[0]->oobavail; + if (subdev[0]->_writev) + concat->mtd._writev = concat_writev; + if (subdev[0]->_read_oob) + concat->mtd._read_oob = concat_read_oob; + if (subdev[0]->_write_oob) + concat->mtd._write_oob = concat_write_oob; + if (subdev[0]->_block_isbad) + concat->mtd._block_isbad = concat_block_isbad; + if (subdev[0]->_block_markbad) + concat->mtd._block_markbad = concat_block_markbad; + + concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks; + + 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; + concat->mtd.ecc_stats.badblocks += + subdev[i]->ecc_stats.badblocks; + if (concat->mtd.writesize != subdev[i]->writesize || + concat->mtd.subpage_sft != subdev[i]->subpage_sft || + concat->mtd.oobsize != subdev[i]->oobsize || + !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]; + + } + + mtd_set_ooblayout(&concat->mtd, subdev[0]->ooblayout); + + concat->num_subdev = num_devs; + concat->mtd.name = name; + + 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 { + uint64_t tmp64; + + /* + * 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; + uint64_t begin, position; + + concat->mtd.erasesize = max_erasesize; + concat->mtd.numeraseregions = num_erase_region; + concat->mtd.eraseregions = erase_region_p = + kmalloc_array(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; + tmp64 = position - begin; + do_div(tmp64, curr_erasesize); + erase_region_p->numblocks = tmp64; + 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; + tmp64 = position - begin; + do_div(tmp64, curr_erasesize); + erase_region_p->numblocks = tmp64; + begin = position; + + curr_erasesize = + subdev[i]->eraseregions[j]. + erasesize; + ++erase_region_p; + } + position += + subdev[i]->eraseregions[j]. + numblocks * (uint64_t)curr_erasesize; + } + } + } + /* Now write the final entry */ + erase_region_p->offset = begin; + erase_region_p->erasesize = curr_erasesize; + tmp64 = position - begin; + do_div(tmp64, curr_erasesize); + erase_region_p->numblocks = tmp64; + } + + 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"); |