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 mtdchar_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 mtdchar_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 mtdchar_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;
167 } /* mtdchar_close */
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 mtdchar_read(struct file *file, char __user *buf, size_t count,
190 struct mtd_file_info *mfi = file->private_data;
191 struct mtd_info *mtd = mfi->mtd;
193 size_t total_retlen=0;
199 pr_debug("MTD_read\n");
201 if (*ppos + count > mtd->size)
202 count = mtd->size - *ppos;
207 kbuf = mtd_kmalloc_up_to(mtd, &size);
212 len = min_t(size_t, count, size);
215 case MTD_FILE_MODE_OTP_FACTORY:
216 ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
219 case MTD_FILE_MODE_OTP_USER:
220 ret = mtd_read_user_prot_reg(mtd, *ppos, len,
223 case MTD_FILE_MODE_RAW:
225 struct mtd_oob_ops ops;
227 ops.mode = MTD_OPS_RAW;
232 ret = mtd_read_oob(mtd, *ppos, &ops);
237 ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
239 /* Nand returns -EBADMSG on ECC errors, but it returns
240 * the data. For our userspace tools it is important
241 * to dump areas with ECC errors!
242 * For kernel internal usage it also might return -EUCLEAN
243 * to signal the caller that a bitflip has occurred and has
244 * been corrected by the ECC algorithm.
245 * Userspace software which accesses NAND this way
246 * must be aware of the fact that it deals with NAND
248 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
250 if (copy_to_user(buf, kbuf, retlen)) {
255 total_retlen += retlen;
273 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
276 struct mtd_file_info *mfi = file->private_data;
277 struct mtd_info *mtd = mfi->mtd;
281 size_t total_retlen=0;
285 pr_debug("MTD_write\n");
287 if (*ppos == mtd->size)
290 if (*ppos + count > mtd->size)
291 count = mtd->size - *ppos;
296 kbuf = mtd_kmalloc_up_to(mtd, &size);
301 len = min_t(size_t, count, size);
303 if (copy_from_user(kbuf, buf, len)) {
309 case MTD_FILE_MODE_OTP_FACTORY:
312 case MTD_FILE_MODE_OTP_USER:
313 if (!mtd->write_user_prot_reg) {
317 ret = mtd_write_user_prot_reg(mtd, *ppos, len,
321 case MTD_FILE_MODE_RAW:
323 struct mtd_oob_ops ops;
325 ops.mode = MTD_OPS_RAW;
331 ret = mtd_write_oob(mtd, *ppos, &ops);
337 ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
341 total_retlen += retlen;
353 } /* mtdchar_write */
355 /*======================================================================
357 IOCTL calls for getting device parameters.
359 ======================================================================*/
360 static void mtdchar_erase_callback (struct erase_info *instr)
362 wake_up((wait_queue_head_t *)instr->priv);
365 #ifdef CONFIG_HAVE_MTD_OTP
366 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
368 struct mtd_info *mtd = mfi->mtd;
372 case MTD_OTP_FACTORY:
373 if (!mtd->read_fact_prot_reg)
376 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
379 if (!mtd->read_fact_prot_reg)
382 mfi->mode = MTD_FILE_MODE_OTP_USER;
392 # define otp_select_filemode(f,m) -EOPNOTSUPP
395 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
396 uint64_t start, uint32_t length, void __user *ptr,
397 uint32_t __user *retp)
399 struct mtd_file_info *mfi = file->private_data;
400 struct mtd_oob_ops ops;
404 if (!(file->f_mode & FMODE_WRITE))
413 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
419 ops.ooboffs = start & (mtd->writesize - 1);
421 ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
424 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
427 ops.oobbuf = memdup_user(ptr, length);
428 if (IS_ERR(ops.oobbuf))
429 return PTR_ERR(ops.oobbuf);
431 start &= ~((uint64_t)mtd->writesize - 1);
432 ret = mtd_write_oob(mtd, start, &ops);
434 if (ops.oobretlen > 0xFFFFFFFFU)
436 retlen = ops.oobretlen;
437 if (copy_to_user(retp, &retlen, sizeof(length)))
444 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
445 uint64_t start, uint32_t length, void __user *ptr,
446 uint32_t __user *retp)
448 struct mtd_file_info *mfi = file->private_data;
449 struct mtd_oob_ops ops;
458 ret = access_ok(VERIFY_WRITE, ptr,
459 length) ? 0 : -EFAULT;
464 ops.ooboffs = start & (mtd->writesize - 1);
466 ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
469 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
472 ops.oobbuf = kmalloc(length, GFP_KERNEL);
476 start &= ~((uint64_t)mtd->writesize - 1);
477 ret = mtd_read_oob(mtd, start, &ops);
479 if (put_user(ops.oobretlen, retp))
481 else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
488 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
489 * data. For our userspace tools it is important to dump areas
491 * For kernel internal usage it also might return -EUCLEAN
492 * to signal the caller that a bitflip has occured and has
493 * been corrected by the ECC algorithm.
495 * Note: currently the standard NAND function, nand_read_oob_std,
496 * does not calculate ECC for the OOB area, so do not rely on
497 * this behavior unless you have replaced it with your own.
499 if (mtd_is_bitflip_or_eccerr(ret))
506 * Copies (and truncates, if necessary) data from the larger struct,
507 * nand_ecclayout, to the smaller, deprecated layout struct,
508 * nand_ecclayout_user. This is necessary only to support the deprecated
509 * API ioctl ECCGETLAYOUT while allowing all new functionality to use
510 * nand_ecclayout flexibly (i.e. the struct may change size in new
511 * releases without requiring major rewrites).
513 static int shrink_ecclayout(const struct nand_ecclayout *from,
514 struct nand_ecclayout_user *to)
521 memset(to, 0, sizeof(*to));
523 to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
524 for (i = 0; i < to->eccbytes; i++)
525 to->eccpos[i] = from->eccpos[i];
527 for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
528 if (from->oobfree[i].length == 0 &&
529 from->oobfree[i].offset == 0)
531 to->oobavail += from->oobfree[i].length;
532 to->oobfree[i] = from->oobfree[i];
538 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
539 struct blkpg_ioctl_arg __user *arg)
541 struct blkpg_ioctl_arg a;
542 struct blkpg_partition p;
544 if (!capable(CAP_SYS_ADMIN))
547 if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
550 if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
554 case BLKPG_ADD_PARTITION:
556 /* Only master mtd device must be used to add partitions */
557 if (mtd_is_partition(mtd))
560 return mtd_add_partition(mtd, p.devname, p.start, p.length);
562 case BLKPG_DEL_PARTITION:
567 return mtd_del_partition(mtd, p.pno);
574 static int mtdchar_write_ioctl(struct mtd_info *mtd,
575 struct mtd_write_req __user *argp)
577 struct mtd_write_req req;
578 struct mtd_oob_ops ops;
579 void __user *usr_data, *usr_oob;
582 if (copy_from_user(&req, argp, sizeof(req)) ||
583 !access_ok(VERIFY_READ, req.usr_data, req.len) ||
584 !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
590 ops.len = (size_t)req.len;
591 ops.ooblen = (size_t)req.ooblen;
594 usr_data = (void __user *)(uintptr_t)req.usr_data;
595 usr_oob = (void __user *)(uintptr_t)req.usr_oob;
598 ops.datbuf = memdup_user(usr_data, ops.len);
599 if (IS_ERR(ops.datbuf))
600 return PTR_ERR(ops.datbuf);
606 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
607 if (IS_ERR(ops.oobbuf)) {
609 return PTR_ERR(ops.oobbuf);
615 ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
623 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
625 struct mtd_file_info *mfi = file->private_data;
626 struct mtd_info *mtd = mfi->mtd;
627 void __user *argp = (void __user *)arg;
630 struct mtd_info_user info;
632 pr_debug("MTD_ioctl\n");
634 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
636 if (!access_ok(VERIFY_READ, argp, size))
640 if (!access_ok(VERIFY_WRITE, argp, size))
645 case MEMGETREGIONCOUNT:
646 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
650 case MEMGETREGIONINFO:
653 struct mtd_erase_region_info *kr;
654 struct region_info_user __user *ur = argp;
656 if (get_user(ur_idx, &(ur->regionindex)))
659 if (ur_idx >= mtd->numeraseregions)
662 kr = &(mtd->eraseregions[ur_idx]);
664 if (put_user(kr->offset, &(ur->offset))
665 || put_user(kr->erasesize, &(ur->erasesize))
666 || put_user(kr->numblocks, &(ur->numblocks)))
673 memset(&info, 0, sizeof(info));
674 info.type = mtd->type;
675 info.flags = mtd->flags;
676 info.size = mtd->size;
677 info.erasesize = mtd->erasesize;
678 info.writesize = mtd->writesize;
679 info.oobsize = mtd->oobsize;
680 /* The below field is obsolete */
682 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
689 struct erase_info *erase;
691 if(!(file->f_mode & FMODE_WRITE))
694 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
698 wait_queue_head_t waitq;
699 DECLARE_WAITQUEUE(wait, current);
701 init_waitqueue_head(&waitq);
703 if (cmd == MEMERASE64) {
704 struct erase_info_user64 einfo64;
706 if (copy_from_user(&einfo64, argp,
707 sizeof(struct erase_info_user64))) {
711 erase->addr = einfo64.start;
712 erase->len = einfo64.length;
714 struct erase_info_user einfo32;
716 if (copy_from_user(&einfo32, argp,
717 sizeof(struct erase_info_user))) {
721 erase->addr = einfo32.start;
722 erase->len = einfo32.length;
725 erase->callback = mtdchar_erase_callback;
726 erase->priv = (unsigned long)&waitq;
729 FIXME: Allow INTERRUPTIBLE. Which means
730 not having the wait_queue head on the stack.
732 If the wq_head is on the stack, and we
733 leave because we got interrupted, then the
734 wq_head is no longer there when the
735 callback routine tries to wake us up.
737 ret = mtd_erase(mtd, erase);
739 set_current_state(TASK_UNINTERRUPTIBLE);
740 add_wait_queue(&waitq, &wait);
741 if (erase->state != MTD_ERASE_DONE &&
742 erase->state != MTD_ERASE_FAILED)
744 remove_wait_queue(&waitq, &wait);
745 set_current_state(TASK_RUNNING);
747 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
756 struct mtd_oob_buf buf;
757 struct mtd_oob_buf __user *buf_user = argp;
759 /* NOTE: writes return length to buf_user->length */
760 if (copy_from_user(&buf, argp, sizeof(buf)))
763 ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
764 buf.ptr, &buf_user->length);
770 struct mtd_oob_buf buf;
771 struct mtd_oob_buf __user *buf_user = argp;
773 /* NOTE: writes return length to buf_user->start */
774 if (copy_from_user(&buf, argp, sizeof(buf)))
777 ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
778 buf.ptr, &buf_user->start);
784 struct mtd_oob_buf64 buf;
785 struct mtd_oob_buf64 __user *buf_user = argp;
787 if (copy_from_user(&buf, argp, sizeof(buf)))
790 ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
791 (void __user *)(uintptr_t)buf.usr_ptr,
798 struct mtd_oob_buf64 buf;
799 struct mtd_oob_buf64 __user *buf_user = argp;
801 if (copy_from_user(&buf, argp, sizeof(buf)))
804 ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
805 (void __user *)(uintptr_t)buf.usr_ptr,
812 ret = mtdchar_write_ioctl(mtd,
813 (struct mtd_write_req __user *)arg);
819 struct erase_info_user einfo;
821 if (copy_from_user(&einfo, argp, sizeof(einfo)))
827 ret = mtd->lock(mtd, einfo.start, einfo.length);
833 struct erase_info_user einfo;
835 if (copy_from_user(&einfo, argp, sizeof(einfo)))
841 ret = mtd->unlock(mtd, einfo.start, einfo.length);
847 struct erase_info_user einfo;
849 if (copy_from_user(&einfo, argp, sizeof(einfo)))
855 ret = mtd->is_locked(mtd, einfo.start, einfo.length);
859 /* Legacy interface */
862 struct nand_oobinfo oi;
866 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
869 oi.useecc = MTD_NANDECC_AUTOPLACE;
870 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
871 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
873 oi.eccbytes = mtd->ecclayout->eccbytes;
875 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
884 if (copy_from_user(&offs, argp, sizeof(loff_t)))
886 if (!mtd->block_isbad)
889 return mtd->block_isbad(mtd, offs);
897 if (copy_from_user(&offs, argp, sizeof(loff_t)))
899 if (!mtd->block_markbad)
902 return mtd->block_markbad(mtd, offs);
906 #ifdef CONFIG_HAVE_MTD_OTP
910 if (copy_from_user(&mode, argp, sizeof(int)))
913 mfi->mode = MTD_FILE_MODE_NORMAL;
915 ret = otp_select_filemode(mfi, mode);
921 case OTPGETREGIONCOUNT:
922 case OTPGETREGIONINFO:
924 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
929 case MTD_FILE_MODE_OTP_FACTORY:
930 if (mtd->get_fact_prot_info)
931 ret = mtd_get_fact_prot_info(mtd, buf, 4096);
933 case MTD_FILE_MODE_OTP_USER:
934 if (mtd->get_user_prot_info)
935 ret = mtd_get_user_prot_info(mtd, buf, 4096);
941 if (cmd == OTPGETREGIONCOUNT) {
942 int nbr = ret / sizeof(struct otp_info);
943 ret = copy_to_user(argp, &nbr, sizeof(int));
945 ret = copy_to_user(argp, buf, ret);
955 struct otp_info oinfo;
957 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
959 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
961 if (!mtd->lock_user_prot_reg)
963 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
968 /* This ioctl is being deprecated - it truncates the ECC layout */
971 struct nand_ecclayout_user *usrlay;
976 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
980 shrink_ecclayout(mtd->ecclayout, usrlay);
982 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
990 if (copy_to_user(argp, &mtd->ecc_stats,
991 sizeof(struct mtd_ecc_stats)))
1001 case MTD_FILE_MODE_OTP_FACTORY:
1002 case MTD_FILE_MODE_OTP_USER:
1003 ret = otp_select_filemode(mfi, arg);
1006 case MTD_FILE_MODE_RAW:
1007 if (!mtd->read_oob || !mtd->write_oob)
1011 case MTD_FILE_MODE_NORMAL:
1022 ret = mtdchar_blkpg_ioctl(mtd,
1023 (struct blkpg_ioctl_arg __user *)arg);
1029 /* No reread partition feature. Just return ok */
1039 } /* memory_ioctl */
1041 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1045 mutex_lock(&mtd_mutex);
1046 ret = mtdchar_ioctl(file, cmd, arg);
1047 mutex_unlock(&mtd_mutex);
1052 #ifdef CONFIG_COMPAT
1054 struct mtd_oob_buf32 {
1057 compat_caddr_t ptr; /* unsigned char* */
1060 #define MEMWRITEOOB32 _IOWR('M', 3, struct mtd_oob_buf32)
1061 #define MEMREADOOB32 _IOWR('M', 4, struct mtd_oob_buf32)
1063 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1066 struct mtd_file_info *mfi = file->private_data;
1067 struct mtd_info *mtd = mfi->mtd;
1068 void __user *argp = compat_ptr(arg);
1071 mutex_lock(&mtd_mutex);
1076 struct mtd_oob_buf32 buf;
1077 struct mtd_oob_buf32 __user *buf_user = argp;
1079 if (copy_from_user(&buf, argp, sizeof(buf)))
1082 ret = mtdchar_writeoob(file, mtd, buf.start,
1083 buf.length, compat_ptr(buf.ptr),
1090 struct mtd_oob_buf32 buf;
1091 struct mtd_oob_buf32 __user *buf_user = argp;
1093 /* NOTE: writes return length to buf->start */
1094 if (copy_from_user(&buf, argp, sizeof(buf)))
1097 ret = mtdchar_readoob(file, mtd, buf.start,
1098 buf.length, compat_ptr(buf.ptr),
1103 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1106 mutex_unlock(&mtd_mutex);
1111 #endif /* CONFIG_COMPAT */
1114 * try to determine where a shared mapping can be made
1115 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1119 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1122 unsigned long pgoff,
1123 unsigned long flags)
1125 struct mtd_file_info *mfi = file->private_data;
1126 struct mtd_info *mtd = mfi->mtd;
1128 if (mtd->get_unmapped_area) {
1129 unsigned long offset;
1132 return (unsigned long) -EINVAL;
1134 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1135 return (unsigned long) -EINVAL;
1137 offset = pgoff << PAGE_SHIFT;
1138 if (offset > mtd->size - len)
1139 return (unsigned long) -EINVAL;
1141 return mtd_get_unmapped_area(mtd, len, offset, flags);
1144 /* can't map directly */
1145 return (unsigned long) -ENOSYS;
1150 * set up a mapping for shared memory segments
1152 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1155 struct mtd_file_info *mfi = file->private_data;
1156 struct mtd_info *mtd = mfi->mtd;
1157 struct map_info *map = mtd->priv;
1158 unsigned long start;
1162 if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1163 off = vma->vm_pgoff << PAGE_SHIFT;
1165 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1167 if ((vma->vm_end - vma->vm_start + off) > len)
1171 vma->vm_pgoff = off >> PAGE_SHIFT;
1172 vma->vm_flags |= VM_IO | VM_RESERVED;
1174 #ifdef pgprot_noncached
1175 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1176 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1178 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1179 vma->vm_end - vma->vm_start,
1187 return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1191 static const struct file_operations mtd_fops = {
1192 .owner = THIS_MODULE,
1193 .llseek = mtdchar_lseek,
1194 .read = mtdchar_read,
1195 .write = mtdchar_write,
1196 .unlocked_ioctl = mtdchar_unlocked_ioctl,
1197 #ifdef CONFIG_COMPAT
1198 .compat_ioctl = mtdchar_compat_ioctl,
1200 .open = mtdchar_open,
1201 .release = mtdchar_close,
1202 .mmap = mtdchar_mmap,
1204 .get_unmapped_area = mtdchar_get_unmapped_area,
1208 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1209 int flags, const char *dev_name, void *data)
1211 return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1214 static struct file_system_type mtd_inodefs_type = {
1215 .name = "mtd_inodefs",
1216 .mount = mtd_inodefs_mount,
1217 .kill_sb = kill_anon_super,
1220 static void mtdchar_notify_add(struct mtd_info *mtd)
1224 static void mtdchar_notify_remove(struct mtd_info *mtd)
1226 struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1229 /* Destroy the inode if it exists */
1230 clear_nlink(mtd_ino);
1235 static struct mtd_notifier mtdchar_notifier = {
1236 .add = mtdchar_notify_add,
1237 .remove = mtdchar_notify_remove,
1240 static int __init init_mtdchar(void)
1244 ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1247 pr_notice("Can't allocate major number %d for "
1248 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1252 ret = register_filesystem(&mtd_inodefs_type);
1254 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1255 goto err_unregister_chdev;
1258 mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1259 if (IS_ERR(mtd_inode_mnt)) {
1260 ret = PTR_ERR(mtd_inode_mnt);
1261 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1262 goto err_unregister_filesystem;
1264 register_mtd_user(&mtdchar_notifier);
1268 err_unregister_filesystem:
1269 unregister_filesystem(&mtd_inodefs_type);
1270 err_unregister_chdev:
1271 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1275 static void __exit cleanup_mtdchar(void)
1277 unregister_mtd_user(&mtdchar_notifier);
1278 kern_unmount(mtd_inode_mnt);
1279 unregister_filesystem(&mtd_inodefs_type);
1280 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1283 module_init(init_mtdchar);
1284 module_exit(cleanup_mtdchar);
1286 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1288 MODULE_LICENSE("GPL");
1289 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1290 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1291 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);