diff options
Diffstat (limited to 'drivers/mtd/mtdcore.c')
| -rw-r--r-- | drivers/mtd/mtdcore.c | 167 |
1 files changed, 119 insertions, 48 deletions
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index da69bc8a5a7d..c510aff289a8 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -24,6 +24,7 @@ #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> @@ -37,6 +38,7 @@ #include <linux/gfp.h> #include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> #include "mtdcore.h" /* @@ -391,7 +393,7 @@ fail_locked: * if the requested device does not appear to be present in the list. */ -int del_mtd_device (struct mtd_info *mtd) +int del_mtd_device(struct mtd_info *mtd) { int ret; struct mtd_notifier *not; @@ -427,6 +429,50 @@ out_error: } /** + * 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 * @@ -443,7 +489,7 @@ void register_mtd_user (struct mtd_notifier *new) list_add(&new->list, &mtd_notifiers); - __module_get(THIS_MODULE); + __module_get(THIS_MODULE); mtd_for_each_device(mtd) new->add(mtd); @@ -532,7 +578,6 @@ int __get_mtd_device(struct mtd_info *mtd) return -ENODEV; if (mtd->get_device) { - err = mtd->get_device(mtd); if (err) { @@ -570,21 +615,13 @@ struct mtd_info *get_mtd_device_nm(const char *name) if (!mtd) goto out_unlock; - if (!try_module_get(mtd->owner)) + err = __get_mtd_device(mtd); + if (err) goto out_unlock; - if (mtd->get_device) { - err = mtd->get_device(mtd); - if (err) - goto out_put; - } - - mtd->usecount++; mutex_unlock(&mtd_table_mutex); return mtd; -out_put: - module_put(mtd->owner); out_unlock: mutex_unlock(&mtd_table_mutex); return ERR_PTR(err); @@ -638,8 +675,54 @@ int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, return ret; } -EXPORT_SYMBOL_GPL(add_mtd_device); -EXPORT_SYMBOL_GPL(del_mtd_device); +/** + * 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); @@ -648,6 +731,7 @@ 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 @@ -656,44 +740,32 @@ EXPORT_SYMBOL_GPL(default_mtd_writev); static struct proc_dir_entry *proc_mtd; -static inline int mtd_proc_info(char *buf, struct mtd_info *this) -{ - return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", this->index, - (unsigned long long)this->size, - this->erasesize, this->name); -} - -static int mtd_read_proc (char *page, char **start, off_t off, int count, - int *eof, void *data_unused) +static int mtd_proc_show(struct seq_file *m, void *v) { struct mtd_info *mtd; - int len, l; - off_t begin = 0; + seq_puts(m, "dev: size erasesize name\n"); mutex_lock(&mtd_table_mutex); - - len = sprintf(page, "dev: size erasesize name\n"); mtd_for_each_device(mtd) { - l = mtd_proc_info(page + len, mtd); - len += l; - if (len+begin > off+count) - goto done; - if (len+begin < off) { - begin += len; - len = 0; - } - } - - *eof = 1; - -done: + 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); - if (off >= len+begin) - return 0; - *start = page + (off-begin); - return ((count < begin+len-off) ? count : begin+len-off); + 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 */ /*====================================================================*/ @@ -734,8 +806,7 @@ static int __init init_mtd(void) goto err_bdi3; #ifdef CONFIG_PROC_FS - if ((proc_mtd = create_proc_entry( "mtd", 0, NULL ))) - proc_mtd->read_proc = mtd_read_proc; + proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops); #endif /* CONFIG_PROC_FS */ return 0; @@ -753,7 +824,7 @@ err_reg: static void __exit cleanup_mtd(void) { #ifdef CONFIG_PROC_FS - if (proc_mtd) + if (proc_mtd) remove_proc_entry( "mtd", NULL); #endif /* CONFIG_PROC_FS */ class_unregister(&mtd_class); |