2 * Character-device access to raw MTD devices.
6 #include <linux/device.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/sched.h>
15 #include <linux/smp_lock.h>
16 #include <linux/backing-dev.h>
17 #include <linux/compat.h>
18 #include <linux/mount.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/compatmac.h>
23 #include <asm/uaccess.h>
25 #define MTD_INODE_FS_MAGIC 0x11307854
26 static struct vfsmount *mtd_inode_mnt __read_mostly;
29 * Data structure to hold the pointer to the mtd device as well
30 * as mode information ofr various use cases.
32 struct mtd_file_info {
35 enum mtd_file_modes mode;
38 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
40 struct mtd_file_info *mfi = file->private_data;
41 struct mtd_info *mtd = mfi->mtd;
47 offset += file->f_pos;
56 if (offset >= 0 && offset <= mtd->size)
57 return file->f_pos = offset;
64 static int mtd_open(struct inode *inode, struct file *file)
66 int minor = iminor(inode);
67 int devnum = minor >> 1;
70 struct mtd_file_info *mfi;
71 struct inode *mtd_ino;
73 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
75 /* You can't open the RO devices RW */
76 if ((file->f_mode & FMODE_WRITE) && (minor & 1))
80 mtd = get_mtd_device(NULL, devnum);
87 if (mtd->type == MTD_ABSENT) {
93 mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
99 if (mtd_ino->i_state & I_NEW) {
100 mtd_ino->i_private = mtd;
101 mtd_ino->i_mode = S_IFCHR;
102 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
103 unlock_new_inode(mtd_ino);
105 file->f_mapping = mtd_ino->i_mapping;
107 /* You can't open it RW if it's not a writeable device */
108 if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
115 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
124 file->private_data = mfi;
131 /*====================================================================*/
133 static int mtd_close(struct inode *inode, struct file *file)
135 struct mtd_file_info *mfi = file->private_data;
136 struct mtd_info *mtd = mfi->mtd;
138 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
140 /* Only sync if opened RW */
141 if ((file->f_mode & FMODE_WRITE) && mtd->sync)
147 file->private_data = NULL;
153 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
154 userspace buffer down and use it directly with readv/writev.
156 #define MAX_KMALLOC_SIZE 0x20000
158 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
160 struct mtd_file_info *mfi = file->private_data;
161 struct mtd_info *mtd = mfi->mtd;
163 size_t total_retlen=0;
168 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
170 if (*ppos + count > mtd->size)
171 count = mtd->size - *ppos;
176 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
177 and pass them directly to the MTD functions */
179 if (count > MAX_KMALLOC_SIZE)
180 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
182 kbuf=kmalloc(count, GFP_KERNEL);
189 if (count > MAX_KMALLOC_SIZE)
190 len = MAX_KMALLOC_SIZE;
195 case MTD_MODE_OTP_FACTORY:
196 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
198 case MTD_MODE_OTP_USER:
199 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
203 struct mtd_oob_ops ops;
205 ops.mode = MTD_OOB_RAW;
210 ret = mtd->read_oob(mtd, *ppos, &ops);
215 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
217 /* Nand returns -EBADMSG on ecc errors, but it returns
218 * the data. For our userspace tools it is important
219 * to dump areas with ecc errors !
220 * For kernel internal usage it also might return -EUCLEAN
221 * to signal the caller that a bitflip has occured and has
222 * been corrected by the ECC algorithm.
223 * Userspace software which accesses NAND this way
224 * must be aware of the fact that it deals with NAND
226 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
228 if (copy_to_user(buf, kbuf, retlen)) {
233 total_retlen += retlen;
251 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
253 struct mtd_file_info *mfi = file->private_data;
254 struct mtd_info *mtd = mfi->mtd;
257 size_t total_retlen=0;
261 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
263 if (*ppos == mtd->size)
266 if (*ppos + count > mtd->size)
267 count = mtd->size - *ppos;
272 if (count > MAX_KMALLOC_SIZE)
273 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
275 kbuf=kmalloc(count, GFP_KERNEL);
282 if (count > MAX_KMALLOC_SIZE)
283 len = MAX_KMALLOC_SIZE;
287 if (copy_from_user(kbuf, buf, len)) {
293 case MTD_MODE_OTP_FACTORY:
296 case MTD_MODE_OTP_USER:
297 if (!mtd->write_user_prot_reg) {
301 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
306 struct mtd_oob_ops ops;
308 ops.mode = MTD_OOB_RAW;
313 ret = mtd->write_oob(mtd, *ppos, &ops);
319 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
323 total_retlen += retlen;
337 /*======================================================================
339 IOCTL calls for getting device parameters.
341 ======================================================================*/
342 static void mtdchar_erase_callback (struct erase_info *instr)
344 wake_up((wait_queue_head_t *)instr->priv);
347 #ifdef CONFIG_HAVE_MTD_OTP
348 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
350 struct mtd_info *mtd = mfi->mtd;
354 case MTD_OTP_FACTORY:
355 if (!mtd->read_fact_prot_reg)
358 mfi->mode = MTD_MODE_OTP_FACTORY;
361 if (!mtd->read_fact_prot_reg)
364 mfi->mode = MTD_MODE_OTP_USER;
374 # define otp_select_filemode(f,m) -EOPNOTSUPP
377 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
378 uint64_t start, uint32_t length, void __user *ptr,
379 uint32_t __user *retp)
381 struct mtd_oob_ops ops;
385 if (!(file->f_mode & FMODE_WRITE))
394 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
400 ops.ooboffs = start & (mtd->oobsize - 1);
402 ops.mode = MTD_OOB_PLACE;
404 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
407 ops.oobbuf = kmalloc(length, GFP_KERNEL);
411 if (copy_from_user(ops.oobbuf, ptr, length)) {
416 start &= ~((uint64_t)mtd->oobsize - 1);
417 ret = mtd->write_oob(mtd, start, &ops);
419 if (ops.oobretlen > 0xFFFFFFFFU)
421 retlen = ops.oobretlen;
422 if (copy_to_user(retp, &retlen, sizeof(length)))
429 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
430 uint32_t length, void __user *ptr, uint32_t __user *retp)
432 struct mtd_oob_ops ops;
441 ret = access_ok(VERIFY_WRITE, ptr,
442 length) ? 0 : -EFAULT;
447 ops.ooboffs = start & (mtd->oobsize - 1);
449 ops.mode = MTD_OOB_PLACE;
451 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
454 ops.oobbuf = kmalloc(length, GFP_KERNEL);
458 start &= ~((uint64_t)mtd->oobsize - 1);
459 ret = mtd->read_oob(mtd, start, &ops);
461 if (put_user(ops.oobretlen, retp))
463 else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
471 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
473 struct mtd_file_info *mfi = file->private_data;
474 struct mtd_info *mtd = mfi->mtd;
475 void __user *argp = (void __user *)arg;
478 struct mtd_info_user info;
480 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
482 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
484 if (!access_ok(VERIFY_READ, argp, size))
488 if (!access_ok(VERIFY_WRITE, argp, size))
493 case MEMGETREGIONCOUNT:
494 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
498 case MEMGETREGIONINFO:
501 struct mtd_erase_region_info *kr;
502 struct region_info_user __user *ur = argp;
504 if (get_user(ur_idx, &(ur->regionindex)))
507 kr = &(mtd->eraseregions[ur_idx]);
509 if (put_user(kr->offset, &(ur->offset))
510 || put_user(kr->erasesize, &(ur->erasesize))
511 || put_user(kr->numblocks, &(ur->numblocks)))
518 info.type = mtd->type;
519 info.flags = mtd->flags;
520 info.size = mtd->size;
521 info.erasesize = mtd->erasesize;
522 info.writesize = mtd->writesize;
523 info.oobsize = mtd->oobsize;
524 /* The below fields are obsolete */
527 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
534 struct erase_info *erase;
536 if(!(file->f_mode & FMODE_WRITE))
539 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
543 wait_queue_head_t waitq;
544 DECLARE_WAITQUEUE(wait, current);
546 init_waitqueue_head(&waitq);
548 if (cmd == MEMERASE64) {
549 struct erase_info_user64 einfo64;
551 if (copy_from_user(&einfo64, argp,
552 sizeof(struct erase_info_user64))) {
556 erase->addr = einfo64.start;
557 erase->len = einfo64.length;
559 struct erase_info_user einfo32;
561 if (copy_from_user(&einfo32, argp,
562 sizeof(struct erase_info_user))) {
566 erase->addr = einfo32.start;
567 erase->len = einfo32.length;
570 erase->callback = mtdchar_erase_callback;
571 erase->priv = (unsigned long)&waitq;
574 FIXME: Allow INTERRUPTIBLE. Which means
575 not having the wait_queue head on the stack.
577 If the wq_head is on the stack, and we
578 leave because we got interrupted, then the
579 wq_head is no longer there when the
580 callback routine tries to wake us up.
582 ret = mtd->erase(mtd, erase);
584 set_current_state(TASK_UNINTERRUPTIBLE);
585 add_wait_queue(&waitq, &wait);
586 if (erase->state != MTD_ERASE_DONE &&
587 erase->state != MTD_ERASE_FAILED)
589 remove_wait_queue(&waitq, &wait);
590 set_current_state(TASK_RUNNING);
592 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
601 struct mtd_oob_buf buf;
602 struct mtd_oob_buf __user *buf_user = argp;
604 /* NOTE: writes return length to buf_user->length */
605 if (copy_from_user(&buf, argp, sizeof(buf)))
608 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
609 buf.ptr, &buf_user->length);
615 struct mtd_oob_buf buf;
616 struct mtd_oob_buf __user *buf_user = argp;
618 /* NOTE: writes return length to buf_user->start */
619 if (copy_from_user(&buf, argp, sizeof(buf)))
622 ret = mtd_do_readoob(mtd, buf.start, buf.length,
623 buf.ptr, &buf_user->start);
629 struct mtd_oob_buf64 buf;
630 struct mtd_oob_buf64 __user *buf_user = argp;
632 if (copy_from_user(&buf, argp, sizeof(buf)))
635 ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
636 (void __user *)(uintptr_t)buf.usr_ptr,
643 struct mtd_oob_buf64 buf;
644 struct mtd_oob_buf64 __user *buf_user = argp;
646 if (copy_from_user(&buf, argp, sizeof(buf)))
649 ret = mtd_do_readoob(mtd, buf.start, buf.length,
650 (void __user *)(uintptr_t)buf.usr_ptr,
657 struct erase_info_user einfo;
659 if (copy_from_user(&einfo, argp, sizeof(einfo)))
665 ret = mtd->lock(mtd, einfo.start, einfo.length);
671 struct erase_info_user einfo;
673 if (copy_from_user(&einfo, argp, sizeof(einfo)))
679 ret = mtd->unlock(mtd, einfo.start, einfo.length);
683 /* Legacy interface */
686 struct nand_oobinfo oi;
690 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
693 oi.useecc = MTD_NANDECC_AUTOPLACE;
694 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
695 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
697 oi.eccbytes = mtd->ecclayout->eccbytes;
699 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
708 if (copy_from_user(&offs, argp, sizeof(loff_t)))
710 if (!mtd->block_isbad)
713 return mtd->block_isbad(mtd, offs);
721 if (copy_from_user(&offs, argp, sizeof(loff_t)))
723 if (!mtd->block_markbad)
726 return mtd->block_markbad(mtd, offs);
730 #ifdef CONFIG_HAVE_MTD_OTP
734 if (copy_from_user(&mode, argp, sizeof(int)))
737 mfi->mode = MTD_MODE_NORMAL;
739 ret = otp_select_filemode(mfi, mode);
745 case OTPGETREGIONCOUNT:
746 case OTPGETREGIONINFO:
748 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
753 case MTD_MODE_OTP_FACTORY:
754 if (mtd->get_fact_prot_info)
755 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
757 case MTD_MODE_OTP_USER:
758 if (mtd->get_user_prot_info)
759 ret = mtd->get_user_prot_info(mtd, buf, 4096);
765 if (cmd == OTPGETREGIONCOUNT) {
766 int nbr = ret / sizeof(struct otp_info);
767 ret = copy_to_user(argp, &nbr, sizeof(int));
769 ret = copy_to_user(argp, buf, ret);
779 struct otp_info oinfo;
781 if (mfi->mode != MTD_MODE_OTP_USER)
783 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
785 if (!mtd->lock_user_prot_reg)
787 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
797 if (copy_to_user(argp, mtd->ecclayout,
798 sizeof(struct nand_ecclayout)))
805 if (copy_to_user(argp, &mtd->ecc_stats,
806 sizeof(struct mtd_ecc_stats)))
816 case MTD_MODE_OTP_FACTORY:
817 case MTD_MODE_OTP_USER:
818 ret = otp_select_filemode(mfi, arg);
822 if (!mtd->read_oob || !mtd->write_oob)
826 case MTD_MODE_NORMAL:
842 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
847 ret = mtd_ioctl(file, cmd, arg);
855 struct mtd_oob_buf32 {
858 compat_caddr_t ptr; /* unsigned char* */
861 #define MEMWRITEOOB32 _IOWR('M', 3, struct mtd_oob_buf32)
862 #define MEMREADOOB32 _IOWR('M', 4, struct mtd_oob_buf32)
864 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
867 struct mtd_file_info *mfi = file->private_data;
868 struct mtd_info *mtd = mfi->mtd;
869 void __user *argp = compat_ptr(arg);
877 struct mtd_oob_buf32 buf;
878 struct mtd_oob_buf32 __user *buf_user = argp;
880 if (copy_from_user(&buf, argp, sizeof(buf)))
883 ret = mtd_do_writeoob(file, mtd, buf.start,
884 buf.length, compat_ptr(buf.ptr),
891 struct mtd_oob_buf32 buf;
892 struct mtd_oob_buf32 __user *buf_user = argp;
894 /* NOTE: writes return length to buf->start */
895 if (copy_from_user(&buf, argp, sizeof(buf)))
898 ret = mtd_do_readoob(mtd, buf.start,
899 buf.length, compat_ptr(buf.ptr),
904 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
912 #endif /* CONFIG_COMPAT */
915 * try to determine where a shared mapping can be made
916 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
920 static unsigned long mtd_get_unmapped_area(struct file *file,
926 struct mtd_file_info *mfi = file->private_data;
927 struct mtd_info *mtd = mfi->mtd;
929 if (mtd->get_unmapped_area) {
930 unsigned long offset;
933 return (unsigned long) -EINVAL;
935 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
936 return (unsigned long) -EINVAL;
938 offset = pgoff << PAGE_SHIFT;
939 if (offset > mtd->size - len)
940 return (unsigned long) -EINVAL;
942 return mtd->get_unmapped_area(mtd, len, offset, flags);
945 /* can't map directly */
946 return (unsigned long) -ENOSYS;
951 * set up a mapping for shared memory segments
953 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
956 struct mtd_file_info *mfi = file->private_data;
957 struct mtd_info *mtd = mfi->mtd;
959 if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
963 return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
967 static const struct file_operations mtd_fops = {
968 .owner = THIS_MODULE,
972 .unlocked_ioctl = mtd_unlocked_ioctl,
974 .compat_ioctl = mtd_compat_ioctl,
977 .release = mtd_close,
980 .get_unmapped_area = mtd_get_unmapped_area,
984 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
985 const char *dev_name, void *data,
986 struct vfsmount *mnt)
988 return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
992 static struct file_system_type mtd_inodefs_type = {
993 .name = "mtd_inodefs",
994 .get_sb = mtd_inodefs_get_sb,
995 .kill_sb = kill_anon_super,
998 static void mtdchar_notify_add(struct mtd_info *mtd)
1002 static void mtdchar_notify_remove(struct mtd_info *mtd)
1004 struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1007 /* Destroy the inode if it exists */
1008 mtd_ino->i_nlink = 0;
1013 static struct mtd_notifier mtdchar_notifier = {
1014 .add = mtdchar_notify_add,
1015 .remove = mtdchar_notify_remove,
1018 static int __init init_mtdchar(void)
1022 ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1025 pr_notice("Can't allocate major number %d for "
1026 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1030 ret = register_filesystem(&mtd_inodefs_type);
1032 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1033 goto err_unregister_chdev;
1036 mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1037 if (IS_ERR(mtd_inode_mnt)) {
1038 ret = PTR_ERR(mtd_inode_mnt);
1039 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1040 goto err_unregister_filesystem;
1042 register_mtd_user(&mtdchar_notifier);
1046 err_unregister_filesystem:
1047 unregister_filesystem(&mtd_inodefs_type);
1048 err_unregister_chdev:
1049 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1053 static void __exit cleanup_mtdchar(void)
1055 unregister_mtd_user(&mtdchar_notifier);
1056 mntput(mtd_inode_mnt);
1057 unregister_filesystem(&mtd_inodefs_type);
1058 __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1061 module_init(init_mtdchar);
1062 module_exit(cleanup_mtdchar);
1064 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1066 MODULE_LICENSE("GPL");
1067 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1068 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1069 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);