Viewing file:  mtdchar.c (11.06 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* $Id: mtdchar.c,v 1.44 2001/10/02 15:05:11 dwmw2 Exp $
*
* Character-device access to raw MTD devices.
* Pure 2.4 version - compatibility cruft removed to mtdchar-compat.c
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/slab.h>
#ifdef CONFIG_DEVFS_FS
#include <linux/devfs_fs_kernel.h>
static void mtd_notify_add(struct mtd_info* mtd);
static void mtd_notify_remove(struct mtd_info* mtd);
static struct mtd_notifier notifier = {
add: mtd_notify_add,
remove: mtd_notify_remove,
};
static devfs_handle_t devfs_dir_handle;
static devfs_handle_t devfs_rw_handle[MAX_MTD_DEVICES];
static devfs_handle_t devfs_ro_handle[MAX_MTD_DEVICES];
#endif
static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
{
struct mtd_info *mtd=(struct mtd_info *)file->private_data;
switch (orig) {
case 0:
/* SEEK_SET */
file->f_pos = offset;
break;
case 1:
/* SEEK_CUR */
file->f_pos += offset;
break;
case 2:
/* SEEK_END */
file->f_pos =mtd->size + offset;
break;
default:
return -EINVAL;
}
if (file->f_pos < 0)
file->f_pos = 0;
else if (file->f_pos >= mtd->size)
file->f_pos = mtd->size - 1;
return file->f_pos;
}
static int mtd_open(struct inode *inode, struct file *file)
{
int minor = MINOR(inode->i_rdev);
int devnum = minor >> 1;
struct mtd_info *mtd;
DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
if (devnum >= MAX_MTD_DEVICES)
return -ENODEV;
/* You can't open the RO devices RW */
if ((file->f_mode & 2) && (minor & 1))
return -EACCES;
mtd = get_mtd_device(NULL, devnum);
if (!mtd)
return -ENODEV;
if (MTD_ABSENT == mtd->type) {
put_mtd_device(mtd);
return -ENODEV;
}
file->private_data = mtd;
/* You can't open it RW if it's not a writeable device */
if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
put_mtd_device(mtd);
return -EACCES;
}
return 0;
} /* mtd_open */
/*====================================================================*/
static int mtd_close(struct inode *inode, struct file *file)
{
struct mtd_info *mtd;
DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
mtd = (struct mtd_info *)file->private_data;
if (mtd->sync)
mtd->sync(mtd);
put_mtd_device(mtd);
return 0;
} /* mtd_close */
/* FIXME: This _really_ needs to die. In 2.5, we should lock the
userspace buffer down and use it directly with readv/writev.
*/
#define MAX_KMALLOC_SIZE 0x20000
static ssize_t mtd_read(struct file *file, char *buf, size_t count,loff_t *ppos)
{
struct mtd_info *mtd = (struct mtd_info *)file->private_data;
size_t retlen=0;
size_t total_retlen=0;
int ret=0;
int len;
char *kbuf;
DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
if (*ppos + count > mtd->size)
count = mtd->size - *ppos;
if (!count)
return 0;
/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
and pass them directly to the MTD functions */
while (count) {
if (count > MAX_KMALLOC_SIZE)
len = MAX_KMALLOC_SIZE;
else
len = count;
kbuf=kmalloc(len,GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
ret = MTD_READ(mtd, *ppos, len, &retlen, kbuf);
if (!ret) {
*ppos += retlen;
if (copy_to_user(buf, kbuf, retlen)) {
kfree(kbuf);
return -EFAULT;
}
else
total_retlen += retlen;
count -= retlen;
buf += retlen;
}
else {
kfree(kbuf);
return ret;
}
kfree(kbuf);
}
return total_retlen;
} /* mtd_read */
static ssize_t mtd_write(struct file *file, const char *buf, size_t count,loff_t *ppos)
{
struct mtd_info *mtd = (struct mtd_info *)file->private_data;
char *kbuf;
size_t retlen;
size_t total_retlen=0;
int ret=0;
int len;
DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
if (*ppos == mtd->size)
return -ENOSPC;
if (*ppos + count > mtd->size)
count = mtd->size - *ppos;
if (!count)
return 0;
while (count) {
if (count > MAX_KMALLOC_SIZE)
len = MAX_KMALLOC_SIZE;
else
len = count;
kbuf=kmalloc(len,GFP_KERNEL);
if (!kbuf) {
printk("kmalloc is null\n");
return -ENOMEM;
}
if (copy_from_user(kbuf, buf, len)) {
kfree(kbuf);
return -EFAULT;
}
ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
if (!ret) {
*ppos += retlen;
total_retlen += retlen;
count -= retlen;
buf += retlen;
}
else {
kfree(kbuf);
return ret;
}
kfree(kbuf);
}
return total_retlen;
} /* mtd_write */
/*======================================================================
IOCTL calls for getting device parameters.
======================================================================*/
static void mtd_erase_callback (struct erase_info *instr)
{
wake_up((wait_queue_head_t *)instr->priv);
}
static int mtd_ioctl(struct inode *inode, struct file *file,
u_int cmd, u_long arg)
{
struct mtd_info *mtd = (struct mtd_info *)file->private_data;
int ret = 0;
u_long size;
DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
if (cmd & IOC_IN) {
ret = verify_area(VERIFY_READ, (char *)arg, size);
if (ret) return ret;
}
if (cmd & IOC_OUT) {
ret = verify_area(VERIFY_WRITE, (char *)arg, size);
if (ret) return ret;
}
switch (cmd) {
case MEMGETREGIONCOUNT:
if (copy_to_user((int *) arg, &(mtd->numeraseregions), sizeof(int)))
return -EFAULT;
break;
case MEMGETREGIONINFO:
{
struct region_info_user ur;
if (copy_from_user( &ur,
(struct region_info_user *)arg,
sizeof(struct region_info_user))) {
return -EFAULT;
}
if (ur.regionindex >= mtd->numeraseregions)
return -EINVAL;
if (copy_to_user((struct mtd_erase_region_info *) arg,
&(mtd->eraseregions[ur.regionindex]),
sizeof(struct mtd_erase_region_info)))
return -EFAULT;
break;
}
case MEMGETINFO:
if (copy_to_user((struct mtd_info *)arg, mtd,
sizeof(struct mtd_info_user)))
return -EFAULT;
break;
case MEMERASE:
{
struct erase_info *erase=kmalloc(sizeof(struct erase_info),GFP_KERNEL);
if (!erase)
ret = -ENOMEM;
else {
wait_queue_head_t waitq;
DECLARE_WAITQUEUE(wait, current);
init_waitqueue_head(&waitq);
memset (erase,0,sizeof(struct erase_info));
if (copy_from_user(&erase->addr, (u_long *)arg,
2 * sizeof(u_long))) {
kfree(erase);
return -EFAULT;
}
erase->mtd = mtd;
erase->callback = mtd_erase_callback;
erase->priv = (unsigned long)&waitq;
/*
FIXME: Allow INTERRUPTIBLE. Which means
not having the wait_queue head on the stack.
If the wq_head is on the stack, and we
leave because we got interrupted, then the
wq_head is no longer there when the
callback routine tries to wake us up.
*/
ret = mtd->erase(mtd, erase);
if (!ret) {
set_current_state(TASK_UNINTERRUPTIBLE);
add_wait_queue(&waitq, &wait);
if (erase->state != MTD_ERASE_DONE &&
erase->state != MTD_ERASE_FAILED)
schedule();
remove_wait_queue(&waitq, &wait);
set_current_state(TASK_RUNNING);
ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
}
kfree(erase);
}
break;
}
case MEMWRITEOOB:
{
struct mtd_oob_buf buf;
void *databuf;
ssize_t retlen;
if (copy_from_user(&buf, (struct mtd_oob_buf *)arg, sizeof(struct mtd_oob_buf)))
return -EFAULT;
if (buf.length > 0x4096)
return -EINVAL;
if (!mtd->write_oob)
ret = -EOPNOTSUPP;
else
ret = verify_area(VERIFY_READ, (char *)buf.ptr, buf.length);
if (ret)
return ret;
databuf = kmalloc(buf.length, GFP_KERNEL);
if (!databuf)
return -ENOMEM;
if (copy_from_user(databuf, buf.ptr, buf.length)) {
kfree(databuf);
return -EFAULT;
}
ret = (mtd->write_oob)(mtd, buf.start, buf.length, &retlen, databuf);
if (copy_to_user((void *)arg + sizeof(u_int32_t), &retlen, sizeof(u_int32_t)))
ret = -EFAULT;
kfree(databuf);
break;
}
case MEMREADOOB:
{
struct mtd_oob_buf buf;
void *databuf;
ssize_t retlen;
if (copy_from_user(&buf, (struct mtd_oob_buf *)arg, sizeof(struct mtd_oob_buf)))
return -EFAULT;
if (buf.length > 0x4096)
return -EINVAL;
if (!mtd->read_oob)
ret = -EOPNOTSUPP;
else
ret = verify_area(VERIFY_WRITE, (char *)buf.ptr, buf.length);
if (ret)
return ret;
databuf = kmalloc(buf.length, GFP_KERNEL);
if (!databuf)
return -ENOMEM;
ret = (mtd->read_oob)(mtd, buf.start, buf.length, &retlen, databuf);
if (copy_to_user((void *)arg + sizeof(u_int32_t), &retlen, sizeof(u_int32_t)))
ret = -EFAULT;
else if (retlen && copy_to_user(buf.ptr, databuf, retlen))
ret = -EFAULT;
kfree(databuf);
break;
}
case MEMLOCK:
{
unsigned long adrs[2];
if (copy_from_user(adrs ,(void *)arg, 2* sizeof(unsigned long)))
return -EFAULT;
if (!mtd->lock)
ret = -EOPNOTSUPP;
else
ret = mtd->lock(mtd, adrs[0], adrs[1]);
break;
}
case MEMUNLOCK:
{
unsigned long adrs[2];
if (copy_from_user(adrs, (void *)arg, 2* sizeof(unsigned long)))
return -EFAULT;
if (!mtd->unlock)
ret = -EOPNOTSUPP;
else
ret = mtd->unlock(mtd, adrs[0], adrs[1]);
break;
}
default:
DEBUG(MTD_DEBUG_LEVEL0, "Invalid ioctl %x (MEMGETINFO = %x)\n", cmd, MEMGETINFO);
ret = -ENOTTY;
}
return ret;
} /* memory_ioctl */
static struct file_operations mtd_fops = {
owner: THIS_MODULE,
llseek: mtd_lseek, /* lseek */
read: mtd_read, /* read */
write: mtd_write, /* write */
ioctl: mtd_ioctl, /* ioctl */
open: mtd_open, /* open */
release: mtd_close, /* release */
};
#ifdef CONFIG_DEVFS_FS
/* Notification that a new device has been added. Create the devfs entry for
* it. */
static void mtd_notify_add(struct mtd_info* mtd)
{
char name[8];
if (!mtd)
return;
sprintf(name, "%d", mtd->index);
devfs_rw_handle[mtd->index] = devfs_register(devfs_dir_handle, name,
DEVFS_FL_DEFAULT, MTD_CHAR_MAJOR, mtd->index*2,
S_IFCHR | S_IRUGO | S_IWUGO,
&mtd_fops, NULL);
sprintf(name, "%dro", mtd->index);
devfs_ro_handle[mtd->index] = devfs_register(devfs_dir_handle, name,
DEVFS_FL_DEFAULT, MTD_CHAR_MAJOR, mtd->index*2+1,
S_IFCHR | S_IRUGO | S_IWUGO,
&mtd_fops, NULL);
}
static void mtd_notify_remove(struct mtd_info* mtd)
{
if (!mtd)
return;
devfs_unregister(devfs_rw_handle[mtd->index]);
devfs_unregister(devfs_ro_handle[mtd->index]);
}
#endif
static int __init init_mtdchar(void)
{
#ifdef CONFIG_DEVFS_FS
if (devfs_register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops))
{
printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
MTD_CHAR_MAJOR);
return -EAGAIN;
}
devfs_dir_handle = devfs_mk_dir(NULL, "mtd", NULL);
register_mtd_user(¬ifier);
#else
if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops))
{
printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
MTD_CHAR_MAJOR);
return -EAGAIN;
}
#endif
return 0;
}
static void __exit cleanup_mtdchar(void)
{
#ifdef CONFIG_DEVFS_FS
unregister_mtd_user(¬ifier);
devfs_unregister(devfs_dir_handle);
devfs_unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
#else
unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
#endif
}
module_init(init_mtdchar);
module_exit(cleanup_mtdchar);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Direct character-device access to MTD devices");
|