2 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include <linux/device.h>
23 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/sched.h>
29 #include <linux/mutex.h>
30 #include <linux/backing-dev.h>
31 #include <linux/compat.h>
32 #include <linux/mount.h>
33 #include <linux/blkpg.h>
34 #include <linux/mtd/mtd.h>
35 #include <linux/mtd/partitions.h>
36 #include <linux/mtd/map.h>
38 #include <asm/uaccess.h>
40 #define MTD_INODE_FS_MAGIC 0x11307854
41 static DEFINE_MUTEX(mtd_mutex);
42 static struct vfsmount *mtd_inode_mnt __read_mostly;
45 * Data structure to hold the pointer to the mtd device as well
46 * as mode information ofr various use cases.
48 struct mtd_file_info {
51 enum mtd_file_modes mode;
54 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
56 struct mtd_file_info *mfi = file->private_data;
57 struct mtd_info *mtd = mfi->mtd;
63 offset += file->f_pos;
72 if (offset >= 0 && offset <= mtd->size)
73 return file->f_pos = offset;
80 static int mtd_open(struct inode *inode, struct file *file)
82 int minor = iminor(inode);
83 int devnum = minor >> 1;
86 struct mtd_file_info *mfi;
87 struct inode *mtd_ino;
89 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
91 /* You can't open the RO devices RW */
92 if ((file->f_mode & FMODE_WRITE) && (minor & 1))
95 mutex_lock(&mtd_mutex);
96 mtd = get_mtd_device(NULL, devnum);
103 if (mtd->type == MTD_ABSENT) {
109 mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
115 if (mtd_ino->i_state & I_NEW) {
116 mtd_ino->i_private = mtd;
117 mtd_ino->i_mode = S_IFCHR;
118 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
119 unlock_new_inode(mtd_ino);
121 file->f_mapping = mtd_ino->i_mapping;
123 /* You can't open it RW if it's not a writeable device */
124 if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
131 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
140 file->private_data = mfi;
143 mutex_unlock(&mtd_mutex);
147 /*====================================================================*/
149 static int mtd_close(struct inode *inode, struct file *file)
151 struct mtd_file_info *mfi = file->private_data;
152 struct mtd_info *mtd = mfi->mtd;
154 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
156 /* Only sync if opened RW */
157 if ((file->f_mode & FMODE_WRITE) && mtd->sync)
163 file->private_data = NULL;
169 /* Back in June 2001, dwmw2 wrote:
171 * FIXME: This _really_ needs to die. In 2.5, we should lock the
172 * userspace buffer down and use it directly with readv/writev.
174 * The implementation below, using mtd_kmalloc_up_to, mitigates
175 * allocation failures when the system is under low-memory situations
176 * or if memory is highly fragmented at the cost of reducing the
177 * performance of the requested transfer due to a smaller buffer size.
179 * A more complex but more memory-efficient implementation based on
180 * get_user_pages and iovecs to cover extents of those pages is a
181 * longer-term goal, as intimated by dwmw2 above. However, for the
182 * write case, this requires yet more complex head and tail transfer
183 * handling when those head and tail offsets and sizes are such that
184 * alignment requirements are not met in the NAND subdriver.
187 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
189 struct mtd_file_info *mfi = file->private_data;
190 struct mtd_info *mtd = mfi->mtd;
192 size_t total_retlen=0;
198 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
200 if (*ppos + count > mtd->size)
201 count = mtd->size - *ppos;
206 kbuf = mtd_kmalloc_up_to(mtd, &size);
211 len = min_t(size_t, count, size);
214 case MTD_MODE_OTP_FACTORY:
215 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
217 case MTD_MODE_OTP_USER:
218 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
222 struct mtd_oob_ops ops;
224 ops.mode = MTD_OOB_RAW;
229 ret = mtd->read_oob(mtd, *ppos, &ops);
234 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
236 /* Nand returns -EBADMSG on ecc errors, but it returns
237 * the data. For our userspace tools it is important
238 * to dump areas with ecc errors !
239 * For kernel internal usage it also might return -EUCLEAN
240 * to signal the caller that a bitflip has occurred and has
241 * been corrected by the ECC algorithm.
242 * Userspace software which accesses NAND this way
243 * must be aware of the fact that it deals with NAND
245 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
247 if (copy_to_user(buf, kbuf, retlen)) {
252 total_retlen += retlen;
270 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
272 struct mtd_file_info *mfi = file->private_data;
273 struct mtd_info *mtd = mfi->mtd;
277 size_t total_retlen=0;
281 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
283 if (*ppos == mtd->size)
286 if (*ppos + count > mtd->size)
287 count = mtd->size - *ppos;
292 kbuf = mtd_kmalloc_up_to(mtd, &size);
297 len = min_t(size_t, count, size);
299 if (copy_from_user(kbuf, buf, len)) {
305 case MTD_MODE_OTP_FACTORY:
308 case MTD_MODE_OTP_USER:
309 if (!mtd->write_user_prot_reg) {
313 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
318 struct mtd_oob_ops ops;
320 ops.mode = MTD_OOB_RAW;
326 ret = mtd->write_oob(mtd, *ppos, &ops);
332 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
336 total_retlen += retlen;
350 /*======================================================================
352 IOCTL calls for getting device parameters.
354 ======================================================================*/
355 static void mtdchar_erase_callback (struct erase_info *instr)
357 wake_up((wait_queue_head_t *)instr->priv);
360 #ifdef CONFIG_HAVE_MTD_OTP
361 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
363 struct mtd_info *mtd = mfi->mtd;
367 case MTD_OTP_FACTORY:
368 if (!mtd->read_fact_prot_reg)
371 mfi->mode = MTD_MODE_OTP_FACTORY;
374 if (!mtd->read_fact_prot_reg)
377 mfi->mode = MTD_MODE_OTP_USER;
387 # define otp_select_filemode(f,m) -EOPNOTSUPP
390 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
391 uint64_t start, uint32_t length, void __user *ptr,
392 uint32_t __user *retp)
394 struct mtd_oob_ops ops;
398 if (!(file->f_mode & FMODE_WRITE))
407 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
413 ops.ooboffs = start & (mtd->oobsize - 1);
415 ops.mode = MTD_OOB_PLACE;
417 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
420 ops.oobbuf = memdup_user(ptr, length);
421 if (IS_ERR(ops.oobbuf))
422 return PTR_ERR(ops.oobbuf);
424 start &= ~((uint64_t)mtd->oobsize - 1);
425 ret = mtd->write_oob(mtd, start, &ops);
427 if (ops.oobretlen > 0xFFFFFFFFU)
429 retlen = ops.oobretlen;
430 if (copy_to_user(retp, &retlen, sizeof(length)))
437 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
438 uint32_t length, void __user *ptr, uint32_t __user *retp)
440 struct mtd_oob_ops ops;
449 ret = access_ok(VERIFY_WRITE, ptr,
450 length) ? 0 : -EFAULT;
455 ops.ooboffs = start & (mtd->oobsize - 1);
457 ops.mode = MTD_OOB_PLACE;
459 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
462 ops.oobbuf = kmalloc(length, GFP_KERNEL);
466 start &= ~((uint64_t)mtd->oobsize - 1);
467 ret = mtd->read_oob(mtd, start, &ops);
469 if (put_user(ops.oobretlen, retp))
471 else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
480 * Copies (and truncates, if necessary) data from the larger struct,
481 * nand_ecclayout, to the smaller, deprecated layout struct,
482 * nand_ecclayout_user. This is necessary only to suppport the deprecated
483 * API ioctl ECCGETLAYOUT while allowing all new functionality to use
484 * nand_ecclayout flexibly (i.e. the struct may change size in new
485 * releases without requiring major rewrites).
487 static int shrink_ecclayout(const struct nand_ecclayout *from,
488 struct nand_ecclayout_user *to)
495 memset(to, 0, sizeof(*to));
497 to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
498 for (i = 0; i < to->eccbytes; i++)
499 to->eccpos[i] = from->eccpos[i];
501 for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
502 if (from->oobfree[i].length == 0 &&
503 from->oobfree[i].offset == 0)
505 to->oobavail += from->oobfree[i].length;
506 to->oobfree[i] = from->oobfree[i];
512 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
513 struct blkpg_ioctl_arg __user *arg)
515 struct blkpg_ioctl_arg a;
516 struct blkpg_partition p;
518 if (!capable(CAP_SYS_ADMIN))
521 if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
524 if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
528 case BLKPG_ADD_PARTITION:
530 /* Only master mtd device must be used to add partitions */
531 if (mtd_is_partition(mtd))
534 return mtd_add_partition(mtd, p.devname, p.start, p.length);
536 case BLKPG_DEL_PARTITION:
541 return mtd_del_partition(mtd, p.pno);
548 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
550 struct mtd_file_info *mfi = file->private_data;
551 struct mtd_info *mtd = mfi->mtd;
552 void __user *argp = (void __user *)arg;
555 struct mtd_info_user info;
557 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
559 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
561 if (!access_ok(VERIFY_READ, argp, size))
565 if (!access_ok(VERIFY_WRITE, argp, size))
570 case MEMGETREGIONCOUNT:
571 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
575 case MEMGETREGIONINFO:
578 struct mtd_erase_region_info *kr;
579 struct region_info_user __user *ur = argp;
581 if (get_user(ur_idx, &(ur->regionindex)))
584 if (ur_idx >= mtd->numeraseregions)
587 kr = &(mtd->eraseregions[ur_idx]);
589 if (put_user(kr->offset, &(ur->offset))
590 || put_user(kr->erasesize, &(ur->erasesize))
591 || put_user(kr->numblocks, &(ur->numblocks)))
598 memset(&info, 0, sizeof(info));
599 info.type = mtd->type;
600 info.flags = mtd->flags;
601 info.size = mtd->size;
602 info.erasesize = mtd->erasesize;
603 info.writesize = mtd->writesize;
604 info.oobsize = mtd->oobsize;
605 /* The below fields are obsolete */
607 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
614 struct erase_info *erase;
616 if(!(file->f_mode & FMODE_WRITE))
619 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
623 wait_queue_head_t waitq;
624 DECLARE_WAITQUEUE(wait, current);
626 init_waitqueue_head(&waitq);
628 if (cmd == MEMERASE64) {
629 struct erase_info_user64 einfo64;
631 if (copy_from_user(&einfo64, argp,
632 sizeof(struct erase_info_user64))) {
636 erase->addr = einfo64.start;
637 erase->len = einfo64.length;
639 struct erase_info_user einfo32;
641 if (copy_from_user(&einfo32, argp,
642 sizeof(struct erase_info_user))) {
646 erase->addr = einfo32.start;
647 erase->len = einfo32.length;
650 erase->callback = mtdchar_erase_callback;
651 erase->priv = (unsigned long)&waitq;
654 FIXME: Allow INTERRUPTIBLE. Which means
655 not having the wait_queue head on the stack.
657 If the wq_head is on the stack, and we
658 leave because we got interrupted, then the
659 wq_head is no longer there when the
660 callback routine tries to wake us up.
662 ret = mtd->erase(mtd, erase);
664 set_current_state(TASK_UNINTERRUPTIBLE);
665 add_wait_queue(&waitq, &wait);
666 if (erase->state != MTD_ERASE_DONE &&
667 erase->state != MTD_ERASE_FAILED)
669 remove_wait_queue(&waitq, &wait);
670 set_current_state(TASK_RUNNING);
672 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
681 struct mtd_oob_buf buf;
682 struct mtd_oob_buf __user *buf_user = argp;
684 /* NOTE: writes return length to buf_user->length */
685 if (copy_from_user(&buf, argp, sizeof(buf)))
688 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
689 buf.ptr, &buf_user->length);
695 struct mtd_oob_buf buf;
696 struct mtd_oob_buf __user *buf_user = argp;
698 /* NOTE: writes return length to buf_user->start */
699 if (copy_from_user(&buf, argp, sizeof(buf)))
702 ret = mtd_do_readoob(mtd, buf.start, buf.length,
703 buf.ptr, &buf_user->start);
709 struct mtd_oob_buf64 buf;
710 struct mtd_oob_buf64 __user *buf_user = argp;
712 if (copy_from_user(&buf, argp, sizeof(buf)))
715 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
716 (void __user *)(uintptr_t)buf.usr_ptr,
723 struct mtd_oob_buf64 buf;
724 struct mtd_oob_buf64 __user *buf_user = argp;
726 if (copy_from_user(&buf, argp, sizeof(buf)))
729 ret = mtd_do_readoob(mtd, buf.start, buf.length,
730 (void __user *)(uintptr_t)buf.usr_ptr,
737 struct erase_info_user einfo;
739 if (copy_from_user(&einfo, argp, sizeof(einfo)))
745 ret = mtd->lock(mtd, einfo.start, einfo.length);
751 struct erase_info_user einfo;
753 if (copy_from_user(&einfo, argp, sizeof(einfo)))
759 ret = mtd->unlock(mtd, einfo.start, einfo.length);
765 struct erase_info_user einfo;
767 if (copy_from_user(&einfo, argp, sizeof(einfo)))
773 ret = mtd->is_locked(mtd, einfo.start, einfo.length);
777 /* Legacy interface */
780 struct nand_oobinfo oi;
784 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
787 oi.useecc = MTD_NANDECC_AUTOPLACE;
788 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
789 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
791 oi.eccbytes = mtd->ecclayout->eccbytes;
793 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
802 if (copy_from_user(&offs, argp, sizeof(loff_t)))
804 if (!mtd->block_isbad)
807 return mtd->block_isbad(mtd, offs);
815 if (copy_from_user(&offs, argp, sizeof(loff_t)))
817 if (!mtd->block_markbad)
820 return mtd->block_markbad(mtd, offs);
824 #ifdef CONFIG_HAVE_MTD_OTP
828 if (copy_from_user(&mode, argp, sizeof(int)))
831 mfi->mode = MTD_MODE_NORMAL;
833 ret = otp_select_filemode(mfi, mode);
839 case OTPGETREGIONCOUNT:
840 case OTPGETREGIONINFO:
842 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
847 case MTD_MODE_OTP_FACTORY:
848 if (mtd->get_fact_prot_info)
849 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
851 case MTD_MODE_OTP_USER:
852 if (mtd->get_user_prot_info)
853 ret = mtd->get_user_prot_info(mtd, buf, 4096);
859 if (cmd == OTPGETREGIONCOUNT) {
860 int nbr = ret / sizeof(struct otp_info);
861 ret = copy_to_user(argp, &nbr, sizeof(int));
863 ret = copy_to_user(argp, buf, ret);
873 struct otp_info oinfo;
875 if (mfi->mode != MTD_MODE_OTP_USER)
877 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
879 if (!mtd->lock_user_prot_reg)
881 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
886 /* This ioctl is being deprecated - it truncates the ecc layout */
889 struct nand_ecclayout_user *usrlay;
894 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
898 shrink_ecclayout(mtd->ecclayout, usrlay);
900 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
908 if (copy_to_user(argp, &mtd->ecc_stats,
909 sizeof(struct mtd_ecc_stats)))
919 case MTD_MODE_OTP_FACTORY:
920 case MTD_MODE_OTP_USER:
921 ret = otp_select_filemode(mfi, arg);
925 if (!mtd->read_oob || !mtd->write_oob)
929 case MTD_MODE_NORMAL:
940 ret = mtd_blkpg_ioctl(mtd,
941 (struct blkpg_ioctl_arg __user *)arg);
947 /* No reread partition feature. Just return ok */
959 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
963 mutex_lock(&mtd_mutex);
964 ret = mtd_ioctl(file, cmd, arg);
965 mutex_unlock(&mtd_mutex);
972 struct mtd_oob_buf32 {
975 compat_caddr_t ptr; /* unsigned char* */
978 #define MEMWRITEOOB32 _IOWR('M', 3, struct mtd_oob_buf32)
979 #define MEMREADOOB32 _IOWR('M', 4, struct mtd_oob_buf32)
981 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
984 struct mtd_file_info *mfi = file->private_data;
985 struct mtd_info *mtd = mfi->mtd;
986 void __user *argp = compat_ptr(arg);
989 mutex_lock(&mtd_mutex);
994 struct mtd_oob_buf32 buf;
995 struct mtd_oob_buf32 __user *buf_user = argp;
997 if (copy_from_user(&buf, argp, sizeof(buf)))
1000 ret = mtd_do_writeoob(file, mtd, buf.start,
1001 buf.length, compat_ptr(buf.ptr),
1008 struct mtd_oob_buf32 buf;
1009 struct mtd_oob_buf32 __user *buf_user = argp;
1011 /* NOTE: writes return length to buf->start */
1012 if (copy_from_user(&buf, argp, sizeof(buf)))
1015 ret = mtd_do_readoob(mtd, buf.start,
1016 buf.length, compat_ptr(buf.ptr),
1021 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1024 mutex_unlock(&mtd_mutex);
1029 #endif /* CONFIG_COMPAT */
1032 * try to determine where a shared mapping can be made
1033 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1037 static unsigned long mtd_get_unmapped_area(struct file *file,
1040 unsigned long pgoff,
1041 unsigned long flags)
1043 struct mtd_file_info *mfi = file->private_data;
1044 struct mtd_info *mtd = mfi->mtd;
1046 if (mtd->get_unmapped_area) {
1047 unsigned long offset;
1050 return (unsigned long) -EINVAL;
1052 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1053 return (unsigned long) -EINVAL;
1055 offset = pgoff << PAGE_SHIFT;
1056 if (offset > mtd->size - len)
1057 return (unsigned long) -EINVAL;
1059 return mtd->get_unmapped_area(mtd, len, offset, flags);
1062 /* can't map directly */
1063 return (unsigned long) -ENOSYS;
1067 static inline unsigned long get_vm_size(struct vm_area_struct *vma)
1069 return vma->vm_end - vma->vm_start;
1072 static inline resource_size_t get_vm_offset(struct vm_area_struct *vma)
1074 return (resource_size_t) vma->vm_pgoff << PAGE_SHIFT;
1078 * Set a new vm offset.
1080 * Verify that the incoming offset really works as a page offset,
1081 * and that the offset and size fit in a resource_size_t.
1083 static inline int set_vm_offset(struct vm_area_struct *vma, resource_size_t off)
1085 pgoff_t pgoff = off >> PAGE_SHIFT;
1086 if (off != (resource_size_t) pgoff << PAGE_SHIFT)
1088 if (off + get_vm_size(vma) - 1 < off)
1090 vma->vm_pgoff = pgoff;
1095 * set up a mapping for shared memory segments
1097 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1100 struct mtd_file_info *mfi = file->private_data;
1101 struct mtd_info *mtd = mfi->mtd;
1102 struct map_info *map = mtd->priv;
1104 /* This is broken because it assumes the MTD device is map-based
1105 and that mtd->priv is a valid struct map_info. It should be
1106 replaced with something that uses the mtd_get_unmapped_area()
1107 operation properly. */
1108 if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1109 #ifdef pgprot_noncached
1110 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1111 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1113 return vm_iomap_memory(vma, map->phys, map->size);
1117 return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1121 static const struct file_operations mtd_fops = {
1122 .owner = THIS_MODULE,
1123 .llseek = mtd_lseek,
1126 .unlocked_ioctl = mtd_unlocked_ioctl,
1127 #ifdef CONFIG_COMPAT
1128 .compat_ioctl = mtd_compat_ioctl,
1131 .release = mtd_close,
1134 .get_unmapped_area = mtd_get_unmapped_area,
1138 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1139 int flags, const char *dev_name, void *data)
1141 return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1144 static struct file_system_type mtd_inodefs_type = {
1145 .name = "mtd_inodefs",
1146 .mount = mtd_inodefs_mount,
1147 .kill_sb = kill_anon_super,
1150 static void mtdchar_notify_add(struct mtd_info *mtd)
1154 static void mtdchar_notify_remove(struct mtd_info *mtd)
1156 struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1159 /* Destroy the inode if it exists */
1160 mtd_ino->i_nlink = 0;
1165 static struct mtd_notifier mtdchar_notifier = {
1166 .add = mtdchar_notify_add,
1167 .remove = mtdchar_notify_remove,
1170 static int __init init_mtdchar(void)
1174 ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1177 pr_notice("Can't allocate major number %d for "
1178 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1182 ret = register_filesystem(&mtd_inodefs_type);
1184 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1185 goto err_unregister_chdev;
1188 mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1189 if (IS_ERR(mtd_inode_mnt)) {
1190 ret = PTR_ERR(mtd_inode_mnt);
1191 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1192 goto err_unregister_filesystem;
1194 register_mtd_user(&mtdchar_notifier);
1198 err_unregister_filesystem:
1199 unregister_filesystem(&mtd_inodefs_type);
1200 err_unregister_chdev:
1201 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1205 static void __exit cleanup_mtdchar(void)
1207 unregister_mtd_user(&mtdchar_notifier);
1208 mntput(mtd_inode_mnt);
1209 unregister_filesystem(&mtd_inodefs_type);
1210 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1213 module_init(init_mtdchar);
1214 module_exit(cleanup_mtdchar);
1216 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1218 MODULE_LICENSE("GPL");
1219 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1220 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1221 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);