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 of 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 pr_debug("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 pr_debug("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 pr_debug("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_OPS_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 pr_debug("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_OPS_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_file_info *mfi = file->private_data;
395 struct mtd_oob_ops ops;
399 if (!(file->f_mode & FMODE_WRITE))
408 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
414 ops.ooboffs = start & (mtd->writesize - 1);
416 ops.mode = (mfi->mode == MTD_MODE_RAW) ? MTD_OPS_RAW :
419 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
422 ops.oobbuf = memdup_user(ptr, length);
423 if (IS_ERR(ops.oobbuf))
424 return PTR_ERR(ops.oobbuf);
426 start &= ~((uint64_t)mtd->writesize - 1);
427 ret = mtd->write_oob(mtd, start, &ops);
429 if (ops.oobretlen > 0xFFFFFFFFU)
431 retlen = ops.oobretlen;
432 if (copy_to_user(retp, &retlen, sizeof(length)))
439 static int mtd_do_readoob(struct file *file, struct mtd_info *mtd,
440 uint64_t start, uint32_t length, void __user *ptr,
441 uint32_t __user *retp)
443 struct mtd_file_info *mfi = file->private_data;
444 struct mtd_oob_ops ops;
453 ret = access_ok(VERIFY_WRITE, ptr,
454 length) ? 0 : -EFAULT;
459 ops.ooboffs = start & (mtd->writesize - 1);
461 ops.mode = (mfi->mode == MTD_MODE_RAW) ? MTD_OPS_RAW :
464 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
467 ops.oobbuf = kmalloc(length, GFP_KERNEL);
471 start &= ~((uint64_t)mtd->writesize - 1);
472 ret = mtd->read_oob(mtd, start, &ops);
474 if (put_user(ops.oobretlen, retp))
476 else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
483 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
484 * data. For our userspace tools it is important to dump areas
486 * For kernel internal usage it also might return -EUCLEAN
487 * to signal the caller that a bitflip has occured and has
488 * been corrected by the ECC algorithm.
490 * Note: currently the standard NAND function, nand_read_oob_std,
491 * does not calculate ECC for the OOB area, so do not rely on
492 * this behavior unless you have replaced it with your own.
494 if (ret == -EUCLEAN || ret == -EBADMSG)
501 * Copies (and truncates, if necessary) data from the larger struct,
502 * nand_ecclayout, to the smaller, deprecated layout struct,
503 * nand_ecclayout_user. This is necessary only to support the deprecated
504 * API ioctl ECCGETLAYOUT while allowing all new functionality to use
505 * nand_ecclayout flexibly (i.e. the struct may change size in new
506 * releases without requiring major rewrites).
508 static int shrink_ecclayout(const struct nand_ecclayout *from,
509 struct nand_ecclayout_user *to)
516 memset(to, 0, sizeof(*to));
518 to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
519 for (i = 0; i < to->eccbytes; i++)
520 to->eccpos[i] = from->eccpos[i];
522 for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
523 if (from->oobfree[i].length == 0 &&
524 from->oobfree[i].offset == 0)
526 to->oobavail += from->oobfree[i].length;
527 to->oobfree[i] = from->oobfree[i];
533 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
534 struct blkpg_ioctl_arg __user *arg)
536 struct blkpg_ioctl_arg a;
537 struct blkpg_partition p;
539 if (!capable(CAP_SYS_ADMIN))
542 if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
545 if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
549 case BLKPG_ADD_PARTITION:
551 /* Only master mtd device must be used to add partitions */
552 if (mtd_is_partition(mtd))
555 return mtd_add_partition(mtd, p.devname, p.start, p.length);
557 case BLKPG_DEL_PARTITION:
562 return mtd_del_partition(mtd, p.pno);
569 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
571 struct mtd_file_info *mfi = file->private_data;
572 struct mtd_info *mtd = mfi->mtd;
573 void __user *argp = (void __user *)arg;
576 struct mtd_info_user info;
578 pr_debug("MTD_ioctl\n");
580 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
582 if (!access_ok(VERIFY_READ, argp, size))
586 if (!access_ok(VERIFY_WRITE, argp, size))
591 case MEMGETREGIONCOUNT:
592 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
596 case MEMGETREGIONINFO:
599 struct mtd_erase_region_info *kr;
600 struct region_info_user __user *ur = argp;
602 if (get_user(ur_idx, &(ur->regionindex)))
605 if (ur_idx >= mtd->numeraseregions)
608 kr = &(mtd->eraseregions[ur_idx]);
610 if (put_user(kr->offset, &(ur->offset))
611 || put_user(kr->erasesize, &(ur->erasesize))
612 || put_user(kr->numblocks, &(ur->numblocks)))
619 memset(&info, 0, sizeof(info));
620 info.type = mtd->type;
621 info.flags = mtd->flags;
622 info.size = mtd->size;
623 info.erasesize = mtd->erasesize;
624 info.writesize = mtd->writesize;
625 info.oobsize = mtd->oobsize;
626 /* The below fields are obsolete */
628 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
635 struct erase_info *erase;
637 if(!(file->f_mode & FMODE_WRITE))
640 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
644 wait_queue_head_t waitq;
645 DECLARE_WAITQUEUE(wait, current);
647 init_waitqueue_head(&waitq);
649 if (cmd == MEMERASE64) {
650 struct erase_info_user64 einfo64;
652 if (copy_from_user(&einfo64, argp,
653 sizeof(struct erase_info_user64))) {
657 erase->addr = einfo64.start;
658 erase->len = einfo64.length;
660 struct erase_info_user einfo32;
662 if (copy_from_user(&einfo32, argp,
663 sizeof(struct erase_info_user))) {
667 erase->addr = einfo32.start;
668 erase->len = einfo32.length;
671 erase->callback = mtdchar_erase_callback;
672 erase->priv = (unsigned long)&waitq;
675 FIXME: Allow INTERRUPTIBLE. Which means
676 not having the wait_queue head on the stack.
678 If the wq_head is on the stack, and we
679 leave because we got interrupted, then the
680 wq_head is no longer there when the
681 callback routine tries to wake us up.
683 ret = mtd->erase(mtd, erase);
685 set_current_state(TASK_UNINTERRUPTIBLE);
686 add_wait_queue(&waitq, &wait);
687 if (erase->state != MTD_ERASE_DONE &&
688 erase->state != MTD_ERASE_FAILED)
690 remove_wait_queue(&waitq, &wait);
691 set_current_state(TASK_RUNNING);
693 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
702 struct mtd_oob_buf buf;
703 struct mtd_oob_buf __user *buf_user = argp;
705 /* NOTE: writes return length to buf_user->length */
706 if (copy_from_user(&buf, argp, sizeof(buf)))
709 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
710 buf.ptr, &buf_user->length);
716 struct mtd_oob_buf buf;
717 struct mtd_oob_buf __user *buf_user = argp;
719 /* NOTE: writes return length to buf_user->start */
720 if (copy_from_user(&buf, argp, sizeof(buf)))
723 ret = mtd_do_readoob(file, mtd, buf.start, buf.length,
724 buf.ptr, &buf_user->start);
730 struct mtd_oob_buf64 buf;
731 struct mtd_oob_buf64 __user *buf_user = argp;
733 if (copy_from_user(&buf, argp, sizeof(buf)))
736 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
737 (void __user *)(uintptr_t)buf.usr_ptr,
744 struct mtd_oob_buf64 buf;
745 struct mtd_oob_buf64 __user *buf_user = argp;
747 if (copy_from_user(&buf, argp, sizeof(buf)))
750 ret = mtd_do_readoob(file, mtd, buf.start, buf.length,
751 (void __user *)(uintptr_t)buf.usr_ptr,
758 struct erase_info_user einfo;
760 if (copy_from_user(&einfo, argp, sizeof(einfo)))
766 ret = mtd->lock(mtd, einfo.start, einfo.length);
772 struct erase_info_user einfo;
774 if (copy_from_user(&einfo, argp, sizeof(einfo)))
780 ret = mtd->unlock(mtd, einfo.start, einfo.length);
786 struct erase_info_user einfo;
788 if (copy_from_user(&einfo, argp, sizeof(einfo)))
794 ret = mtd->is_locked(mtd, einfo.start, einfo.length);
798 /* Legacy interface */
801 struct nand_oobinfo oi;
805 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
808 oi.useecc = MTD_NANDECC_AUTOPLACE;
809 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
810 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
812 oi.eccbytes = mtd->ecclayout->eccbytes;
814 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
823 if (copy_from_user(&offs, argp, sizeof(loff_t)))
825 if (!mtd->block_isbad)
828 return mtd->block_isbad(mtd, offs);
836 if (copy_from_user(&offs, argp, sizeof(loff_t)))
838 if (!mtd->block_markbad)
841 return mtd->block_markbad(mtd, offs);
845 #ifdef CONFIG_HAVE_MTD_OTP
849 if (copy_from_user(&mode, argp, sizeof(int)))
852 mfi->mode = MTD_MODE_NORMAL;
854 ret = otp_select_filemode(mfi, mode);
860 case OTPGETREGIONCOUNT:
861 case OTPGETREGIONINFO:
863 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
868 case MTD_MODE_OTP_FACTORY:
869 if (mtd->get_fact_prot_info)
870 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
872 case MTD_MODE_OTP_USER:
873 if (mtd->get_user_prot_info)
874 ret = mtd->get_user_prot_info(mtd, buf, 4096);
880 if (cmd == OTPGETREGIONCOUNT) {
881 int nbr = ret / sizeof(struct otp_info);
882 ret = copy_to_user(argp, &nbr, sizeof(int));
884 ret = copy_to_user(argp, buf, ret);
894 struct otp_info oinfo;
896 if (mfi->mode != MTD_MODE_OTP_USER)
898 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
900 if (!mtd->lock_user_prot_reg)
902 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
907 /* This ioctl is being deprecated - it truncates the ECC layout */
910 struct nand_ecclayout_user *usrlay;
915 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
919 shrink_ecclayout(mtd->ecclayout, usrlay);
921 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
929 if (copy_to_user(argp, &mtd->ecc_stats,
930 sizeof(struct mtd_ecc_stats)))
940 case MTD_MODE_OTP_FACTORY:
941 case MTD_MODE_OTP_USER:
942 ret = otp_select_filemode(mfi, arg);
946 if (!mtd->read_oob || !mtd->write_oob)
950 case MTD_MODE_NORMAL:
961 ret = mtd_blkpg_ioctl(mtd,
962 (struct blkpg_ioctl_arg __user *)arg);
968 /* No reread partition feature. Just return ok */
980 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
984 mutex_lock(&mtd_mutex);
985 ret = mtd_ioctl(file, cmd, arg);
986 mutex_unlock(&mtd_mutex);
993 struct mtd_oob_buf32 {
996 compat_caddr_t ptr; /* unsigned char* */
999 #define MEMWRITEOOB32 _IOWR('M', 3, struct mtd_oob_buf32)
1000 #define MEMREADOOB32 _IOWR('M', 4, struct mtd_oob_buf32)
1002 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
1005 struct mtd_file_info *mfi = file->private_data;
1006 struct mtd_info *mtd = mfi->mtd;
1007 void __user *argp = compat_ptr(arg);
1010 mutex_lock(&mtd_mutex);
1015 struct mtd_oob_buf32 buf;
1016 struct mtd_oob_buf32 __user *buf_user = argp;
1018 if (copy_from_user(&buf, argp, sizeof(buf)))
1021 ret = mtd_do_writeoob(file, mtd, buf.start,
1022 buf.length, compat_ptr(buf.ptr),
1029 struct mtd_oob_buf32 buf;
1030 struct mtd_oob_buf32 __user *buf_user = argp;
1032 /* NOTE: writes return length to buf->start */
1033 if (copy_from_user(&buf, argp, sizeof(buf)))
1036 ret = mtd_do_readoob(file, mtd, buf.start,
1037 buf.length, compat_ptr(buf.ptr),
1042 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1045 mutex_unlock(&mtd_mutex);
1050 #endif /* CONFIG_COMPAT */
1053 * try to determine where a shared mapping can be made
1054 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1058 static unsigned long mtd_get_unmapped_area(struct file *file,
1061 unsigned long pgoff,
1062 unsigned long flags)
1064 struct mtd_file_info *mfi = file->private_data;
1065 struct mtd_info *mtd = mfi->mtd;
1067 if (mtd->get_unmapped_area) {
1068 unsigned long offset;
1071 return (unsigned long) -EINVAL;
1073 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1074 return (unsigned long) -EINVAL;
1076 offset = pgoff << PAGE_SHIFT;
1077 if (offset > mtd->size - len)
1078 return (unsigned long) -EINVAL;
1080 return mtd->get_unmapped_area(mtd, len, offset, flags);
1083 /* can't map directly */
1084 return (unsigned long) -ENOSYS;
1089 * set up a mapping for shared memory segments
1091 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1094 struct mtd_file_info *mfi = file->private_data;
1095 struct mtd_info *mtd = mfi->mtd;
1096 struct map_info *map = mtd->priv;
1097 unsigned long start;
1101 if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1102 off = vma->vm_pgoff << PAGE_SHIFT;
1104 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1106 if ((vma->vm_end - vma->vm_start + off) > len)
1110 vma->vm_pgoff = off >> PAGE_SHIFT;
1111 vma->vm_flags |= VM_IO | VM_RESERVED;
1113 #ifdef pgprot_noncached
1114 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1115 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1117 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1118 vma->vm_end - vma->vm_start,
1126 return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1130 static const struct file_operations mtd_fops = {
1131 .owner = THIS_MODULE,
1132 .llseek = mtd_lseek,
1135 .unlocked_ioctl = mtd_unlocked_ioctl,
1136 #ifdef CONFIG_COMPAT
1137 .compat_ioctl = mtd_compat_ioctl,
1140 .release = mtd_close,
1143 .get_unmapped_area = mtd_get_unmapped_area,
1147 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1148 int flags, const char *dev_name, void *data)
1150 return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1153 static struct file_system_type mtd_inodefs_type = {
1154 .name = "mtd_inodefs",
1155 .mount = mtd_inodefs_mount,
1156 .kill_sb = kill_anon_super,
1159 static void mtdchar_notify_add(struct mtd_info *mtd)
1163 static void mtdchar_notify_remove(struct mtd_info *mtd)
1165 struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1168 /* Destroy the inode if it exists */
1169 mtd_ino->i_nlink = 0;
1174 static struct mtd_notifier mtdchar_notifier = {
1175 .add = mtdchar_notify_add,
1176 .remove = mtdchar_notify_remove,
1179 static int __init init_mtdchar(void)
1183 ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1186 pr_notice("Can't allocate major number %d for "
1187 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1191 ret = register_filesystem(&mtd_inodefs_type);
1193 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1194 goto err_unregister_chdev;
1197 mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1198 if (IS_ERR(mtd_inode_mnt)) {
1199 ret = PTR_ERR(mtd_inode_mnt);
1200 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1201 goto err_unregister_filesystem;
1203 register_mtd_user(&mtdchar_notifier);
1207 err_unregister_filesystem:
1208 unregister_filesystem(&mtd_inodefs_type);
1209 err_unregister_chdev:
1210 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1214 static void __exit cleanup_mtdchar(void)
1216 unregister_mtd_user(&mtdchar_notifier);
1217 kern_unmount(mtd_inode_mnt);
1218 unregister_filesystem(&mtd_inodefs_type);
1219 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1222 module_init(init_mtdchar);
1223 module_exit(cleanup_mtdchar);
1225 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1227 MODULE_LICENSE("GPL");
1228 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1229 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1230 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);