/* * Core registration and callback routines for MTD * drivers and users. * * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> * Copyright © 2006 Red Hat UK Limited * * 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/module.h> #include <linux/kernel.h> #include <linux/ptrace.h> #include <linux/seq_file.h> #include <linux/string.h> #include <linux/timer.h> #include <linux/major.h> #include <linux/fs.h> #include <linux/err.h> #include <linux/ioctl.h> #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/idr.h> #include <linux/backing-dev.h> #include <linux/gfp.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> #include "mtdcore.h" /* * backing device capabilities for non-mappable devices (such as NAND flash) * - permits private mappings, copies are taken of the data */ static struct backing_dev_info mtd_bdi_unmappable = { .capabilities = BDI_CAP_MAP_COPY, }; /* * backing device capabilities for R/O mappable devices (such as ROM) * - permits private mappings, copies are taken of the data * - permits non-writable shared mappings */ static struct backing_dev_info mtd_bdi_ro_mappable = { .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT | BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP), }; /* * backing device capabilities for writable mappable devices (such as RAM) * - permits private mappings, copies are taken of the data * - permits non-writable shared mappings */ static struct backing_dev_info mtd_bdi_rw_mappable = { .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT | BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP), }; static int mtd_cls_suspend(struct device *dev, pm_message_t state); static int mtd_cls_resume(struct device *dev); static struct class mtd_class = { .name = "mtd", .owner = THIS_MODULE, .suspend = mtd_cls_suspend, .resume = mtd_cls_resume, }; static DEFINE_IDR(mtd_idr); /* These are exported solely for the purpose of mtd_blkdevs.c. You should not use them for _anything_ else */ DEFINE_MUTEX(mtd_table_mutex); EXPORT_SYMBOL_GPL(mtd_table_mutex); struct mtd_info *__mtd_next_device(int i) { return idr_get_next(&mtd_idr, &i); } EXPORT_SYMBOL_GPL(__mtd_next_device); static LIST_HEAD(mtd_notifiers); #if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE) #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2) #else #define MTD_DEVT(index) 0 #endif /* REVISIT once MTD uses the driver model better, whoever allocates * the mtd_info will probably want to use the release() hook... */ static void mtd_release(struct device *dev) { dev_t index = MTD_DEVT(dev_to_mtd(dev)->index); /* remove /dev/mtdXro node if needed */ if (index) device_destroy(&mtd_class, index + 1); } static int mtd_cls_suspend(struct device *dev, pm_message_t state) { struct mtd_info *mtd = dev_to_mtd(dev); if (mtd && mtd->suspend) return mtd->suspend(mtd); else return 0; } static int mtd_cls_resume(struct device *dev) { struct mtd_info *mtd = dev_to_mtd(dev); if (mtd && mtd->resume) mtd->resume(mtd); return 0; } static ssize_t mtd_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); char *type; switch (mtd->type) { case MTD_ABSENT: type = "absent"; break; case MTD_RAM: type = "ram"; break; case MTD_ROM: type = "rom"; break; case MTD_NORFLASH: type = "nor"; break; case MTD_NANDFLASH: type = "nand"; break; case MTD_DATAFLASH: type = "dataflash"; break; case MTD_UBIVOLUME: type = "ubi"; break; default: type = "unknown"; } return snprintf(buf, PAGE_SIZE, "%s\n", type); } static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL); static ssize_t mtd_flags_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags); } static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL); static ssize_t mtd_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "%llu\n", (unsigned long long)mtd->size); } static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL); static ssize_t mtd_erasesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize); } static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL); static ssize_t mtd_writesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize); } static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL); static ssize_t mtd_subpagesize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft; return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize); } static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL); static ssize_t mtd_oobsize_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize); } static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL); static ssize_t mtd_numeraseregions_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions); } static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show, NULL); static ssize_t mtd_name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_to_mtd(dev); return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name); } static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL); static struct attribute *mtd_attrs[] = { &dev_attr_type.attr, &dev_attr_flags.attr, &dev_attr_size.attr, &dev_attr_erasesize.attr, &dev_attr_writesize.attr, &dev_attr_subpagesize.attr, &dev_attr_oobsize.attr, &dev_attr_numeraseregions.attr, &dev_attr_name.attr, NULL, }; static struct attribute_group mtd_group = { .attrs = mtd_attrs, }; static const struct attribute_group *mtd_groups[] = { &mtd_group, NULL, }; static struct device_type mtd_devtype = { .name = "mtd", .groups = mtd_groups, .release = mtd_release, }; /** * add_mtd_device - register an MTD device * @mtd: pointer to new MTD device info structure * * Add a device to the list of MTD devices present in the system, and * notify each currently active MTD 'user' of its arrival. Returns * zero on success or 1 on failure, which currently will only happen * if there is insufficient memory or a sysfs error. */ int add_mtd_device(struct mtd_info *mtd) { struct mtd_notifier *not; int i, error; if (!mtd->backing_dev_info) { switch (mtd->type) { case MTD_RAM: mtd->backing_dev_info = &mtd_bdi_rw_mappable; break; case MTD_ROM: mtd->backing_dev_info = &mtd_bdi_ro_mappable; break; default: mtd->backing_dev_info = &mtd_bdi_unmappable; break; } } BUG_ON(mtd->writesize == 0); mutex_lock(&mtd_table_mutex); do { if (!idr_pre_get(&mtd_idr, GFP_KERNEL)) goto fail_locked; error = idr_get_new(&mtd_idr, mtd, &i); } while (error == -EAGAIN); if (error) goto fail_locked; mtd->index = i; mtd->usecount = 0; if (is_power_of_2(mtd->erasesize)) mtd->erasesize_shift = ffs(mtd->erasesize) - 1; else mtd->erasesize_shift = 0; if (is_power_of_2(mtd->writesize)) mtd->writesize_shift = ffs(mtd->writesize) - 1; else mtd->writesize_shift = 0; mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; /* Some chips always power up locked. Unlock them now */ if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) { if (mtd->unlock(mtd, 0, mtd->size)) printk(KERN_WARNING "%s: unlock failed, writes may not work\n", mtd->name); } /* Caller should have set dev.parent to match the * physical device. */ mtd->dev.type = &mtd_devtype; mtd->dev.class = &mtd_class; mtd->dev.devt = MTD_DEVT(i); dev_set_name(&mtd->dev, "mtd%d", i); dev_set_drvdata(&mtd->dev, mtd); if (device_register(&mtd->dev) != 0) goto fail_added; if (MTD_DEVT(i)) device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL, "mtd%dro", i); DEBUG(0, "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 */ list_for_each_entry(not, &mtd_notifiers, list) not->add(mtd); mutex_unlock(&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. :) */ __module_get(THIS_MODULE); return 0; fail_added: idr_remove(&mtd_idr, i); fail_locked: mutex_unlock(&mtd_table_mutex); 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; struct mtd_notifier *not; mutex_lock(&mtd_table_mutex); if (idr_find(&mtd_idr, mtd->index) != mtd) { ret = -ENODEV; goto out_error; } /* No need to get a refcount on the module containing the notifier, since we hold the mtd_table_mutex */ list_for_each_entry(not, &mtd_notifiers, list) not->remove(mtd); 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 { device_unregister(&mtd->dev); idr_remove(&mtd_idr, mtd->index); module_put(THIS_MODULE); ret = 0; } out_error: mutex_unlock(&mtd_table_mutex); return ret; } /** * mtd_device_register - register an MTD device. * * @master: the MTD device to register * @parts: the partitions to register - only valid if nr_parts > 0 * @nr_parts: the number of partitions in parts. If zero then the full MTD * device is registered * * Register an MTD device with the system and optionally, a number of * partitions. If nr_parts is 0 then the whole device is registered, otherwise * only the partitions are registered. To register both the full device *and* * the partitions, call mtd_device_register() twice, once with nr_parts == 0 * and once equal to the number of partitions. */ int mtd_device_register(struct mtd_info *master, const struct mtd_partition *parts, int nr_parts) { return parts ? add_mtd_partitions(master, parts, nr_parts) : add_mtd_device(master); } EXPORT_SYMBOL_GPL(mtd_device_register); /** * mtd_device_unregister - unregister an existing MTD device. * * @master: the MTD device to unregister. This will unregister both the master * and any partitions if registered. */ int mtd_device_unregister(struct mtd_info *master) { int err; err = del_mtd_partitions(master); if (err) return err; if (!device_is_registered(&master->dev)) return 0; return del_mtd_device(master); } EXPORT_SYMBOL_GPL(mtd_device_unregister); /** * register_mtd_user - register a 'user' of MTD devices. * @new: pointer to notifier info structure * * Registers a pair of callbacks function to be called upon addition * or removal of MTD devices. Causes the 'add' callback to be immediately * invoked for each MTD device currently present in the system. */ void register_mtd_user (struct mtd_notifier *new) { struct mtd_info *mtd; mutex_lock(&mtd_table_mutex); list_add(&new->list, &mtd_notifiers); __module_get(THIS_MODULE); mtd_for_each_device(mtd) new->add(mtd); mutex_unlock(&mtd_table_mutex); } /** * unregister_mtd_user - unregister a 'user' of MTD devices. * @old: pointer to notifier info structure * * Removes a callback function pair from the list of 'users' to be * notified upon addition or removal of MTD devices. Causes the * 'remove' callback to be immediately invoked for each MTD device * currently present in the system. */ int unregister_mtd_user (struct mtd_notifier *old) { struct mtd_info *mtd; mutex_lock(&mtd_table_mutex); module_put(THIS_MODULE); mtd_for_each_device(mtd) old->remove(mtd); list_del(&old->list); mutex_unlock(&mtd_table_mutex); return 0; } /** * 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, *other; int err = -ENODEV; mutex_lock(&mtd_table_mutex); if (num == -1) { mtd_for_each_device(other) { if (other == mtd) { ret = mtd; break; } } } else if (num >= 0) { ret = idr_find(&mtd_idr, num); if (mtd && mtd != ret) ret = NULL; } if (!ret) { ret = ERR_PTR(err); goto out; } err = __get_mtd_device(ret); if (err) ret = ERR_PTR(err); out: mutex_unlock(&mtd_table_mutex); return ret; } int __get_mtd_device(struct mtd_info *mtd) { int err; if (!try_module_get(mtd->owner)) return -ENODEV; if (mtd->get_device) { err = mtd->get_device(mtd); if (err) { module_put(mtd->owner); return err; } } mtd->usecount++; return 0; } /** * 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 err = -ENODEV; struct mtd_info *mtd = NULL, *other; mutex_lock(&mtd_table_mutex); mtd_for_each_device(other) { if (!strcmp(name, other->name)) { mtd = other; break; } } if (!mtd) goto out_unlock; err = __get_mtd_device(mtd); if (err) goto out_unlock; mutex_unlock(&mtd_table_mutex); return mtd; out_unlock: mutex_unlock(&mtd_table_mutex); return ERR_PTR(err); } void put_mtd_device(struct mtd_info *mtd) { mutex_lock(&mtd_table_mutex); __put_mtd_device(mtd); mutex_unlock(&mtd_table_mutex); } void __put_mtd_device(struct mtd_info *mtd) { --mtd->usecount; BUG_ON(mtd->usecount < 0); if (mtd->put_device) mtd->put_device(mtd); module_put(mtd->owner); } /* default_mtd_writev - default mtd writev method for MTD devices that * don't implement their own */ int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen) { unsigned long i; size_t totlen = 0, thislen; int ret = 0; if(!mtd->write) { ret = -EROFS; } else { for (i=0; i<count; i++) { if (!vecs[i].iov_len) continue; ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base); totlen += thislen; if (ret || thislen != vecs[i].iov_len) break; to += vecs[i].iov_len; } } if (retlen) *retlen = totlen; return ret; } /** * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size * @size: A pointer to the ideal or maximum size of the allocation. Points * to the actual allocation size on success. * * This routine attempts to allocate a contiguous kernel buffer up to * the specified size, backing off the size of the request exponentially * until the request succeeds or until the allocation size falls below * the system page size. This attempts to make sure it does not adversely * impact system performance, so when allocating more than one page, we * ask the memory allocator to avoid re-trying, swapping, writing back * or performing I/O. * * Note, this function also makes sure that the allocated buffer is aligned to * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value. * * This is called, for example by mtd_{read,write} and jffs2_scan_medium, * to handle smaller (i.e. degraded) buffer allocations under low- or * fragmented-memory situations where such reduced allocations, from a * requested ideal, are allowed. * * Returns a pointer to the allocated buffer on success; otherwise, NULL. */ void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size) { gfp_t flags = __GFP_NOWARN | __GFP_WAIT | __GFP_NORETRY | __GFP_NO_KSWAPD; size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE); void *kbuf; *size = min_t(size_t, *size, KMALLOC_MAX_SIZE); while (*size > min_alloc) { kbuf = kmalloc(*size, flags); if (kbuf) return kbuf; *size >>= 1; *size = ALIGN(*size, mtd->writesize); } /* * For the last resort allocation allow 'kmalloc()' to do all sorts of * things (write-back, dropping caches, etc) by using GFP_KERNEL. */ return kmalloc(*size, GFP_KERNEL); } EXPORT_SYMBOL_GPL(get_mtd_device); EXPORT_SYMBOL_GPL(get_mtd_device_nm); EXPORT_SYMBOL_GPL(__get_mtd_device); EXPORT_SYMBOL_GPL(put_mtd_device); EXPORT_SYMBOL_GPL(__put_mtd_device); EXPORT_SYMBOL_GPL(register_mtd_user); EXPORT_SYMBOL_GPL(unregister_mtd_user); EXPORT_SYMBOL_GPL(default_mtd_writev); EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to); #ifdef CONFIG_PROC_FS /*====================================================================*/ /* Support for /proc/mtd */ static struct proc_dir_entry *proc_mtd; static int mtd_proc_show(struct seq_file *m, void *v) { struct mtd_info *mtd; seq_puts(m, "dev: size erasesize name\n"); mutex_lock(&mtd_table_mutex); mtd_for_each_device(mtd) { seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n", mtd->index, (unsigned long long)mtd->size, mtd->erasesize, mtd->name); } mutex_unlock(&mtd_table_mutex); return 0; } static int mtd_proc_open(struct inode *inode, struct file *file) { return single_open(file, mtd_proc_show, NULL); } static const struct file_operations mtd_proc_ops = { .open = mtd_proc_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #endif /* CONFIG_PROC_FS */ /*====================================================================*/ /* Init code */ static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name) { int ret; ret = bdi_init(bdi); if (!ret) ret = bdi_register(bdi, NULL, name); if (ret) bdi_destroy(bdi); return ret; } static int __init init_mtd(void) { int ret; ret = class_register(&mtd_class); if (ret) goto err_reg; ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap"); if (ret) goto err_bdi1; ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap"); if (ret) goto err_bdi2; ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap"); if (ret) goto err_bdi3; #ifdef CONFIG_PROC_FS proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops); #endif /* CONFIG_PROC_FS */ return 0; err_bdi3: bdi_destroy(&mtd_bdi_ro_mappable); err_bdi2: bdi_destroy(&mtd_bdi_unmappable); err_bdi1: class_unregister(&mtd_class); err_reg: pr_err("Error registering mtd class or bdi: %d\n", ret); return ret; } static void __exit cleanup_mtd(void) { #ifdef CONFIG_PROC_FS if (proc_mtd) remove_proc_entry( "mtd", NULL); #endif /* CONFIG_PROC_FS */ class_unregister(&mtd_class); bdi_destroy(&mtd_bdi_unmappable); bdi_destroy(&mtd_bdi_ro_mappable); bdi_destroy(&mtd_bdi_rw_mappable); } module_init(init_mtd); module_exit(cleanup_mtd); MODULE_LICENSE("GPL"); MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); MODULE_DESCRIPTION("Core MTD registration and access routines");