mirror of https://gitee.com/openkylin/linux.git
349 lines
8.3 KiB
C
349 lines
8.3 KiB
C
/*
|
|
* $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $
|
|
*
|
|
* Core registration and callback routines for MTD
|
|
* drivers and users.
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/major.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/ioctl.h>
|
|
#include <linux/init.h>
|
|
#include <linux/mtd/compatmac.h>
|
|
#include <linux/proc_fs.h>
|
|
|
|
#include <linux/mtd/mtd.h>
|
|
|
|
/* These are exported solely for the purpose of mtd_blkdevs.c. You
|
|
should not use them for _anything_ else */
|
|
DEFINE_MUTEX(mtd_table_mutex);
|
|
struct mtd_info *mtd_table[MAX_MTD_DEVICES];
|
|
|
|
EXPORT_SYMBOL_GPL(mtd_table_mutex);
|
|
EXPORT_SYMBOL_GPL(mtd_table);
|
|
|
|
static LIST_HEAD(mtd_notifiers);
|
|
|
|
/**
|
|
* 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 the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16)
|
|
*/
|
|
|
|
int add_mtd_device(struct mtd_info *mtd)
|
|
{
|
|
int i;
|
|
|
|
BUG_ON(mtd->writesize == 0);
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
for (i=0; i < MAX_MTD_DEVICES; i++)
|
|
if (!mtd_table[i]) {
|
|
struct list_head *this;
|
|
|
|
mtd_table[i] = mtd;
|
|
mtd->index = i;
|
|
mtd->usecount = 0;
|
|
|
|
/* Some chips always power up locked. Unlock them now */
|
|
if ((mtd->flags & MTD_WRITEABLE)
|
|
&& (mtd->flags & MTD_STUPID_LOCK) && mtd->unlock) {
|
|
if (mtd->unlock(mtd, 0, mtd->size))
|
|
printk(KERN_WARNING
|
|
"%s: unlock failed, "
|
|
"writes may not work\n",
|
|
mtd->name);
|
|
}
|
|
|
|
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(this, &mtd_notifiers) {
|
|
struct mtd_notifier *not = list_entry(this, struct mtd_notifier, 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;
|
|
}
|
|
|
|
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;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
if (mtd_table[mtd->index] != mtd) {
|
|
ret = -ENODEV;
|
|
} else 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 {
|
|
struct list_head *this;
|
|
|
|
/* No need to get a refcount on the module containing
|
|
the notifier, since we hold the mtd_table_mutex */
|
|
list_for_each(this, &mtd_notifiers) {
|
|
struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list);
|
|
not->remove(mtd);
|
|
}
|
|
|
|
mtd_table[mtd->index] = NULL;
|
|
|
|
module_put(THIS_MODULE);
|
|
ret = 0;
|
|
}
|
|
|
|
mutex_unlock(&mtd_table_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
int i;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
list_add(&new->list, &mtd_notifiers);
|
|
|
|
__module_get(THIS_MODULE);
|
|
|
|
for (i=0; i< MAX_MTD_DEVICES; i++)
|
|
if (mtd_table[i])
|
|
new->add(mtd_table[i]);
|
|
|
|
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)
|
|
{
|
|
int i;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
module_put(THIS_MODULE);
|
|
|
|
for (i=0; i< MAX_MTD_DEVICES; i++)
|
|
if (mtd_table[i])
|
|
old->remove(mtd_table[i]);
|
|
|
|
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 NULL
|
|
* if not.
|
|
*/
|
|
|
|
struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
|
|
{
|
|
struct mtd_info *ret = NULL;
|
|
int i;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
if (num == -1) {
|
|
for (i=0; i< MAX_MTD_DEVICES; i++)
|
|
if (mtd_table[i] == mtd)
|
|
ret = mtd_table[i];
|
|
} else if (num < MAX_MTD_DEVICES) {
|
|
ret = mtd_table[num];
|
|
if (mtd && mtd != ret)
|
|
ret = NULL;
|
|
}
|
|
|
|
if (ret && !try_module_get(ret->owner))
|
|
ret = NULL;
|
|
|
|
if (ret)
|
|
ret->usecount++;
|
|
|
|
mutex_unlock(&mtd_table_mutex);
|
|
return ret;
|
|
}
|
|
|
|
void put_mtd_device(struct mtd_info *mtd)
|
|
{
|
|
int c;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
c = --mtd->usecount;
|
|
mutex_unlock(&mtd_table_mutex);
|
|
BUG_ON(c < 0);
|
|
|
|
module_put(mtd->owner);
|
|
}
|
|
|
|
/* default_mtd_writev - default mtd writev method for MTD devices that
|
|
* dont 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;
|
|
}
|
|
|
|
EXPORT_SYMBOL(add_mtd_device);
|
|
EXPORT_SYMBOL(del_mtd_device);
|
|
EXPORT_SYMBOL(get_mtd_device);
|
|
EXPORT_SYMBOL(put_mtd_device);
|
|
EXPORT_SYMBOL(register_mtd_user);
|
|
EXPORT_SYMBOL(unregister_mtd_user);
|
|
EXPORT_SYMBOL(default_mtd_writev);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
/*====================================================================*/
|
|
/* Support for /proc/mtd */
|
|
|
|
static struct proc_dir_entry *proc_mtd;
|
|
|
|
static inline int mtd_proc_info (char *buf, int i)
|
|
{
|
|
struct mtd_info *this = mtd_table[i];
|
|
|
|
if (!this)
|
|
return 0;
|
|
|
|
return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, 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)
|
|
{
|
|
int len, l, i;
|
|
off_t begin = 0;
|
|
|
|
mutex_lock(&mtd_table_mutex);
|
|
|
|
len = sprintf(page, "dev: size erasesize name\n");
|
|
for (i=0; i< MAX_MTD_DEVICES; i++) {
|
|
|
|
l = mtd_proc_info(page + len, i);
|
|
len += l;
|
|
if (len+begin > off+count)
|
|
goto done;
|
|
if (len+begin < off) {
|
|
begin += len;
|
|
len = 0;
|
|
}
|
|
}
|
|
|
|
*eof = 1;
|
|
|
|
done:
|
|
mutex_unlock(&mtd_table_mutex);
|
|
if (off >= len+begin)
|
|
return 0;
|
|
*start = page + (off-begin);
|
|
return ((count < begin+len-off) ? count : begin+len-off);
|
|
}
|
|
|
|
/*====================================================================*/
|
|
/* Init code */
|
|
|
|
static int __init init_mtd(void)
|
|
{
|
|
if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
|
|
proc_mtd->read_proc = mtd_read_proc;
|
|
return 0;
|
|
}
|
|
|
|
static void __exit cleanup_mtd(void)
|
|
{
|
|
if (proc_mtd)
|
|
remove_proc_entry( "mtd", NULL);
|
|
}
|
|
|
|
module_init(init_mtd);
|
|
module_exit(cleanup_mtd);
|
|
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
|
|
MODULE_DESCRIPTION("Core MTD registration and access routines");
|