// SPDX-License-Identifier: GPL-2.0-or-later /* * 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> */ #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_xxlock(struct mtd_info *mtd, loff_t ofs, uint64_t len, bool is_lock) { 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; if (is_lock) err = mtd_lock(subdev, ofs, size); else err = mtd_unlock(subdev, ofs, size); if (err) break; len -= size; if (len == 0) break; err = -EINVAL; ofs = 0; } return err; } static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) { return concat_xxlock(mtd, ofs, len, true); } static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len) { return concat_xxlock(mtd, ofs, len, false); } static int concat_is_locked(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]; if (ofs >= subdev->size) { ofs -= subdev->size; continue; } if (ofs + len > subdev->size) break; return mtd_is_locked(subdev, ofs, len); } 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._is_locked = concat_is_locked; 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");