Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/drivers/mtd/mtdchar.c

  1 /*
  2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
  3  *
  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.
  8  *
  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.
 13  *
 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
 17  *
 18  */
 19 
 20 #include <linux/device.h>
 21 #include <linux/fs.h>
 22 #include <linux/mm.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/magic.h>
 35 #include <linux/major.h>
 36 #include <linux/mtd/mtd.h>
 37 #include <linux/mtd/partitions.h>
 38 #include <linux/mtd/map.h>
 39 
 40 #include <asm/uaccess.h>
 41 
 42 #include "mtdcore.h"
 43 
 44 static DEFINE_MUTEX(mtd_mutex);
 45 
 46 /*
 47  * Data structure to hold the pointer to the mtd device as well
 48  * as mode information of various use cases.
 49  */
 50 struct mtd_file_info {
 51         struct mtd_info *mtd;
 52         struct inode *ino;
 53         enum mtd_file_modes mode;
 54 };
 55 
 56 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
 57 {
 58         struct mtd_file_info *mfi = file->private_data;
 59         return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
 60 }
 61 
 62 static int count;
 63 static struct vfsmount *mnt;
 64 static struct file_system_type mtd_inodefs_type;
 65 
 66 static int mtdchar_open(struct inode *inode, struct file *file)
 67 {
 68         int minor = iminor(inode);
 69         int devnum = minor >> 1;
 70         int ret = 0;
 71         struct mtd_info *mtd;
 72         struct mtd_file_info *mfi;
 73         struct inode *mtd_ino;
 74 
 75         pr_debug("MTD_open\n");
 76 
 77         /* You can't open the RO devices RW */
 78         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
 79                 return -EACCES;
 80 
 81         ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
 82         if (ret)
 83                 return ret;
 84 
 85         mutex_lock(&mtd_mutex);
 86         mtd = get_mtd_device(NULL, devnum);
 87 
 88         if (IS_ERR(mtd)) {
 89                 ret = PTR_ERR(mtd);
 90                 goto out;
 91         }
 92 
 93         if (mtd->type == MTD_ABSENT) {
 94                 ret = -ENODEV;
 95                 goto out1;
 96         }
 97 
 98         mtd_ino = iget_locked(mnt->mnt_sb, devnum);
 99         if (!mtd_ino) {
100                 ret = -ENOMEM;
101                 goto out1;
102         }
103         if (mtd_ino->i_state & I_NEW) {
104                 mtd_ino->i_private = mtd;
105                 mtd_ino->i_mode = S_IFCHR;
106                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
107                 unlock_new_inode(mtd_ino);
108         }
109         file->f_mapping = mtd_ino->i_mapping;
110 
111         /* You can't open it RW if it's not a writeable device */
112         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
113                 ret = -EACCES;
114                 goto out2;
115         }
116 
117         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
118         if (!mfi) {
119                 ret = -ENOMEM;
120                 goto out2;
121         }
122         mfi->ino = mtd_ino;
123         mfi->mtd = mtd;
124         file->private_data = mfi;
125         mutex_unlock(&mtd_mutex);
126         return 0;
127 
128 out2:
129         iput(mtd_ino);
130 out1:
131         put_mtd_device(mtd);
132 out:
133         mutex_unlock(&mtd_mutex);
134         simple_release_fs(&mnt, &count);
135         return ret;
136 } /* mtdchar_open */
137 
138 /*====================================================================*/
139 
140 static int mtdchar_close(struct inode *inode, struct file *file)
141 {
142         struct mtd_file_info *mfi = file->private_data;
143         struct mtd_info *mtd = mfi->mtd;
144 
145         pr_debug("MTD_close\n");
146 
147         /* Only sync if opened RW */
148         if ((file->f_mode & FMODE_WRITE))
149                 mtd_sync(mtd);
150 
151         iput(mfi->ino);
152 
153         put_mtd_device(mtd);
154         file->private_data = NULL;
155         kfree(mfi);
156         simple_release_fs(&mnt, &count);
157 
158         return 0;
159 } /* mtdchar_close */
160 
161 /* Back in June 2001, dwmw2 wrote:
162  *
163  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
164  *   userspace buffer down and use it directly with readv/writev.
165  *
166  * The implementation below, using mtd_kmalloc_up_to, mitigates
167  * allocation failures when the system is under low-memory situations
168  * or if memory is highly fragmented at the cost of reducing the
169  * performance of the requested transfer due to a smaller buffer size.
170  *
171  * A more complex but more memory-efficient implementation based on
172  * get_user_pages and iovecs to cover extents of those pages is a
173  * longer-term goal, as intimated by dwmw2 above. However, for the
174  * write case, this requires yet more complex head and tail transfer
175  * handling when those head and tail offsets and sizes are such that
176  * alignment requirements are not met in the NAND subdriver.
177  */
178 
179 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
180                         loff_t *ppos)
181 {
182         struct mtd_file_info *mfi = file->private_data;
183         struct mtd_info *mtd = mfi->mtd;
184         size_t retlen;
185         size_t total_retlen=0;
186         int ret=0;
187         int len;
188         size_t size = count;
189         char *kbuf;
190 
191         pr_debug("MTD_read\n");
192 
193         if (*ppos + count > mtd->size)
194                 count = mtd->size - *ppos;
195 
196         if (!count)
197                 return 0;
198 
199         kbuf = mtd_kmalloc_up_to(mtd, &size);
200         if (!kbuf)
201                 return -ENOMEM;
202 
203         while (count) {
204                 len = min_t(size_t, count, size);
205 
206                 switch (mfi->mode) {
207                 case MTD_FILE_MODE_OTP_FACTORY:
208                         ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
209                                                      &retlen, kbuf);
210                         break;
211                 case MTD_FILE_MODE_OTP_USER:
212                         ret = mtd_read_user_prot_reg(mtd, *ppos, len,
213                                                      &retlen, kbuf);
214                         break;
215                 case MTD_FILE_MODE_RAW:
216                 {
217                         struct mtd_oob_ops ops;
218 
219                         ops.mode = MTD_OPS_RAW;
220                         ops.datbuf = kbuf;
221                         ops.oobbuf = NULL;
222                         ops.len = len;
223 
224                         ret = mtd_read_oob(mtd, *ppos, &ops);
225                         retlen = ops.retlen;
226                         break;
227                 }
228                 default:
229                         ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
230                 }
231                 /* Nand returns -EBADMSG on ECC errors, but it returns
232                  * the data. For our userspace tools it is important
233                  * to dump areas with ECC errors!
234                  * For kernel internal usage it also might return -EUCLEAN
235                  * to signal the caller that a bitflip has occurred and has
236                  * been corrected by the ECC algorithm.
237                  * Userspace software which accesses NAND this way
238                  * must be aware of the fact that it deals with NAND
239                  */
240                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
241                         *ppos += retlen;
242                         if (copy_to_user(buf, kbuf, retlen)) {
243                                 kfree(kbuf);
244                                 return -EFAULT;
245                         }
246                         else
247                                 total_retlen += retlen;
248 
249                         count -= retlen;
250                         buf += retlen;
251                         if (retlen == 0)
252                                 count = 0;
253                 }
254                 else {
255                         kfree(kbuf);
256                         return ret;
257                 }
258 
259         }
260 
261         kfree(kbuf);
262         return total_retlen;
263 } /* mtdchar_read */
264 
265 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
266                         loff_t *ppos)
267 {
268         struct mtd_file_info *mfi = file->private_data;
269         struct mtd_info *mtd = mfi->mtd;
270         size_t size = count;
271         char *kbuf;
272         size_t retlen;
273         size_t total_retlen=0;
274         int ret=0;
275         int len;
276 
277         pr_debug("MTD_write\n");
278 
279         if (*ppos == mtd->size)
280                 return -ENOSPC;
281 
282         if (*ppos + count > mtd->size)
283                 count = mtd->size - *ppos;
284 
285         if (!count)
286                 return 0;
287 
288         kbuf = mtd_kmalloc_up_to(mtd, &size);
289         if (!kbuf)
290                 return -ENOMEM;
291 
292         while (count) {
293                 len = min_t(size_t, count, size);
294 
295                 if (copy_from_user(kbuf, buf, len)) {
296                         kfree(kbuf);
297                         return -EFAULT;
298                 }
299 
300                 switch (mfi->mode) {
301                 case MTD_FILE_MODE_OTP_FACTORY:
302                         ret = -EROFS;
303                         break;
304                 case MTD_FILE_MODE_OTP_USER:
305                         ret = mtd_write_user_prot_reg(mtd, *ppos, len,
306                                                       &retlen, kbuf);
307                         break;
308 
309                 case MTD_FILE_MODE_RAW:
310                 {
311                         struct mtd_oob_ops ops;
312 
313                         ops.mode = MTD_OPS_RAW;
314                         ops.datbuf = kbuf;
315                         ops.oobbuf = NULL;
316                         ops.ooboffs = 0;
317                         ops.len = len;
318 
319                         ret = mtd_write_oob(mtd, *ppos, &ops);
320                         retlen = ops.retlen;
321                         break;
322                 }
323 
324                 default:
325                         ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
326                 }
327 
328                 /*
329                  * Return -ENOSPC only if no data could be written at all.
330                  * Otherwise just return the number of bytes that actually
331                  * have been written.
332                  */
333                 if ((ret == -ENOSPC) && (total_retlen))
334                         break;
335 
336                 if (!ret) {
337                         *ppos += retlen;
338                         total_retlen += retlen;
339                         count -= retlen;
340                         buf += retlen;
341                 }
342                 else {
343                         kfree(kbuf);
344                         return ret;
345                 }
346         }
347 
348         kfree(kbuf);
349         return total_retlen;
350 } /* mtdchar_write */
351 
352 /*======================================================================
353 
354     IOCTL calls for getting device parameters.
355 
356 ======================================================================*/
357 static void mtdchar_erase_callback (struct erase_info *instr)
358 {
359         wake_up((wait_queue_head_t *)instr->priv);
360 }
361 
362 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
363 {
364         struct mtd_info *mtd = mfi->mtd;
365         size_t retlen;
366 
367         switch (mode) {
368         case MTD_OTP_FACTORY:
369                 if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
370                                 -EOPNOTSUPP)
371                         return -EOPNOTSUPP;
372 
373                 mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
374                 break;
375         case MTD_OTP_USER:
376                 if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
377                                 -EOPNOTSUPP)
378                         return -EOPNOTSUPP;
379 
380                 mfi->mode = MTD_FILE_MODE_OTP_USER;
381                 break;
382         case MTD_OTP_OFF:
383                 mfi->mode = MTD_FILE_MODE_NORMAL;
384                 break;
385         default:
386                 return -EINVAL;
387         }
388 
389         return 0;
390 }
391 
392 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
393         uint64_t start, uint32_t length, void __user *ptr,
394         uint32_t __user *retp)
395 {
396         struct mtd_file_info *mfi = file->private_data;
397         struct mtd_oob_ops ops;
398         uint32_t retlen;
399         int ret = 0;
400 
401         if (!(file->f_mode & FMODE_WRITE))
402                 return -EPERM;
403 
404         if (length > 4096)
405                 return -EINVAL;
406 
407         if (!mtd->_write_oob)
408                 ret = -EOPNOTSUPP;
409         else
410                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
411 
412         if (ret)
413                 return ret;
414 
415         ops.ooblen = length;
416         ops.ooboffs = start & (mtd->writesize - 1);
417         ops.datbuf = NULL;
418         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
419                 MTD_OPS_PLACE_OOB;
420 
421         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
422                 return -EINVAL;
423 
424         ops.oobbuf = memdup_user(ptr, length);
425         if (IS_ERR(ops.oobbuf))
426                 return PTR_ERR(ops.oobbuf);
427 
428         start &= ~((uint64_t)mtd->writesize - 1);
429         ret = mtd_write_oob(mtd, start, &ops);
430 
431         if (ops.oobretlen > 0xFFFFFFFFU)
432                 ret = -EOVERFLOW;
433         retlen = ops.oobretlen;
434         if (copy_to_user(retp, &retlen, sizeof(length)))
435                 ret = -EFAULT;
436 
437         kfree(ops.oobbuf);
438         return ret;
439 }
440 
441 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
442         uint64_t start, uint32_t length, void __user *ptr,
443         uint32_t __user *retp)
444 {
445         struct mtd_file_info *mfi = file->private_data;
446         struct mtd_oob_ops ops;
447         int ret = 0;
448 
449         if (length > 4096)
450                 return -EINVAL;
451 
452         if (!access_ok(VERIFY_WRITE, ptr, length))
453                 return -EFAULT;
454 
455         ops.ooblen = length;
456         ops.ooboffs = start & (mtd->writesize - 1);
457         ops.datbuf = NULL;
458         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
459                 MTD_OPS_PLACE_OOB;
460 
461         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
462                 return -EINVAL;
463 
464         ops.oobbuf = kmalloc(length, GFP_KERNEL);
465         if (!ops.oobbuf)
466                 return -ENOMEM;
467 
468         start &= ~((uint64_t)mtd->writesize - 1);
469         ret = mtd_read_oob(mtd, start, &ops);
470 
471         if (put_user(ops.oobretlen, retp))
472                 ret = -EFAULT;
473         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
474                                             ops.oobretlen))
475                 ret = -EFAULT;
476 
477         kfree(ops.oobbuf);
478 
479         /*
480          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
481          * data. For our userspace tools it is important to dump areas
482          * with ECC errors!
483          * For kernel internal usage it also might return -EUCLEAN
484          * to signal the caller that a bitflip has occured and has
485          * been corrected by the ECC algorithm.
486          *
487          * Note: currently the standard NAND function, nand_read_oob_std,
488          * does not calculate ECC for the OOB area, so do not rely on
489          * this behavior unless you have replaced it with your own.
490          */
491         if (mtd_is_bitflip_or_eccerr(ret))
492                 return 0;
493 
494         return ret;
495 }
496 
497 /*
498  * Copies (and truncates, if necessary) data from the larger struct,
499  * nand_ecclayout, to the smaller, deprecated layout struct,
500  * nand_ecclayout_user. This is necessary only to support the deprecated
501  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
502  * nand_ecclayout flexibly (i.e. the struct may change size in new
503  * releases without requiring major rewrites).
504  */
505 static int shrink_ecclayout(const struct nand_ecclayout *from,
506                 struct nand_ecclayout_user *to)
507 {
508         int i;
509 
510         if (!from || !to)
511                 return -EINVAL;
512 
513         memset(to, 0, sizeof(*to));
514 
515         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
516         for (i = 0; i < to->eccbytes; i++)
517                 to->eccpos[i] = from->eccpos[i];
518 
519         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
520                 if (from->oobfree[i].length == 0 &&
521                                 from->oobfree[i].offset == 0)
522                         break;
523                 to->oobavail += from->oobfree[i].length;
524                 to->oobfree[i] = from->oobfree[i];
525         }
526 
527         return 0;
528 }
529 
530 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
531                            struct blkpg_ioctl_arg __user *arg)
532 {
533         struct blkpg_ioctl_arg a;
534         struct blkpg_partition p;
535 
536         if (!capable(CAP_SYS_ADMIN))
537                 return -EPERM;
538 
539         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
540                 return -EFAULT;
541 
542         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
543                 return -EFAULT;
544 
545         switch (a.op) {
546         case BLKPG_ADD_PARTITION:
547 
548                 /* Only master mtd device must be used to add partitions */
549                 if (mtd_is_partition(mtd))
550                         return -EINVAL;
551 
552                 /* Sanitize user input */
553                 p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
554 
555                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
556 
557         case BLKPG_DEL_PARTITION:
558 
559                 if (p.pno < 0)
560                         return -EINVAL;
561 
562                 return mtd_del_partition(mtd, p.pno);
563 
564         default:
565                 return -EINVAL;
566         }
567 }
568 
569 static int mtdchar_write_ioctl(struct mtd_info *mtd,
570                 struct mtd_write_req __user *argp)
571 {
572         struct mtd_write_req req;
573         struct mtd_oob_ops ops;
574         const void __user *usr_data, *usr_oob;
575         int ret;
576 
577         if (copy_from_user(&req, argp, sizeof(req)))
578                 return -EFAULT;
579 
580         usr_data = (const void __user *)(uintptr_t)req.usr_data;
581         usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
582         if (!access_ok(VERIFY_READ, usr_data, req.len) ||
583             !access_ok(VERIFY_READ, usr_oob, req.ooblen))
584                 return -EFAULT;
585 
586         if (!mtd->_write_oob)
587                 return -EOPNOTSUPP;
588 
589         ops.mode = req.mode;
590         ops.len = (size_t)req.len;
591         ops.ooblen = (size_t)req.ooblen;
592         ops.ooboffs = 0;
593 
594         if (usr_data) {
595                 ops.datbuf = memdup_user(usr_data, ops.len);
596                 if (IS_ERR(ops.datbuf))
597                         return PTR_ERR(ops.datbuf);
598         } else {
599                 ops.datbuf = NULL;
600         }
601 
602         if (usr_oob) {
603                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
604                 if (IS_ERR(ops.oobbuf)) {
605                         kfree(ops.datbuf);
606                         return PTR_ERR(ops.oobbuf);
607                 }
608         } else {
609                 ops.oobbuf = NULL;
610         }
611 
612         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
613 
614         kfree(ops.datbuf);
615         kfree(ops.oobbuf);
616 
617         return ret;
618 }
619 
620 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
621 {
622         struct mtd_file_info *mfi = file->private_data;
623         struct mtd_info *mtd = mfi->mtd;
624         void __user *argp = (void __user *)arg;
625         int ret = 0;
626         u_long size;
627         struct mtd_info_user info;
628 
629         pr_debug("MTD_ioctl\n");
630 
631         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
632         if (cmd & IOC_IN) {
633                 if (!access_ok(VERIFY_READ, argp, size))
634                         return -EFAULT;
635         }
636         if (cmd & IOC_OUT) {
637                 if (!access_ok(VERIFY_WRITE, argp, size))
638                         return -EFAULT;
639         }
640 
641         switch (cmd) {
642         case MEMGETREGIONCOUNT:
643                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
644                         return -EFAULT;
645                 break;
646 
647         case MEMGETREGIONINFO:
648         {
649                 uint32_t ur_idx;
650                 struct mtd_erase_region_info *kr;
651                 struct region_info_user __user *ur = argp;
652 
653                 if (get_user(ur_idx, &(ur->regionindex)))
654                         return -EFAULT;
655 
656                 if (ur_idx >= mtd->numeraseregions)
657                         return -EINVAL;
658 
659                 kr = &(mtd->eraseregions[ur_idx]);
660 
661                 if (put_user(kr->offset, &(ur->offset))
662                     || put_user(kr->erasesize, &(ur->erasesize))
663                     || put_user(kr->numblocks, &(ur->numblocks)))
664                         return -EFAULT;
665 
666                 break;
667         }
668 
669         case MEMGETINFO:
670                 memset(&info, 0, sizeof(info));
671                 info.type       = mtd->type;
672                 info.flags      = mtd->flags;
673                 info.size       = mtd->size;
674                 info.erasesize  = mtd->erasesize;
675                 info.writesize  = mtd->writesize;
676                 info.oobsize    = mtd->oobsize;
677                 /* The below field is obsolete */
678                 info.padding    = 0;
679                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
680                         return -EFAULT;
681                 break;
682 
683         case MEMERASE:
684         case MEMERASE64:
685         {
686                 struct erase_info *erase;
687 
688                 if(!(file->f_mode & FMODE_WRITE))
689                         return -EPERM;
690 
691                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
692                 if (!erase)
693                         ret = -ENOMEM;
694                 else {
695                         wait_queue_head_t waitq;
696                         DECLARE_WAITQUEUE(wait, current);
697 
698                         init_waitqueue_head(&waitq);
699 
700                         if (cmd == MEMERASE64) {
701                                 struct erase_info_user64 einfo64;
702 
703                                 if (copy_from_user(&einfo64, argp,
704                                             sizeof(struct erase_info_user64))) {
705                                         kfree(erase);
706                                         return -EFAULT;
707                                 }
708                                 erase->addr = einfo64.start;
709                                 erase->len = einfo64.length;
710                         } else {
711                                 struct erase_info_user einfo32;
712 
713                                 if (copy_from_user(&einfo32, argp,
714                                             sizeof(struct erase_info_user))) {
715                                         kfree(erase);
716                                         return -EFAULT;
717                                 }
718                                 erase->addr = einfo32.start;
719                                 erase->len = einfo32.length;
720                         }
721                         erase->mtd = mtd;
722                         erase->callback = mtdchar_erase_callback;
723                         erase->priv = (unsigned long)&waitq;
724 
725                         /*
726                           FIXME: Allow INTERRUPTIBLE. Which means
727                           not having the wait_queue head on the stack.
728 
729                           If the wq_head is on the stack, and we
730                           leave because we got interrupted, then the
731                           wq_head is no longer there when the
732                           callback routine tries to wake us up.
733                         */
734                         ret = mtd_erase(mtd, erase);
735                         if (!ret) {
736                                 set_current_state(TASK_UNINTERRUPTIBLE);
737                                 add_wait_queue(&waitq, &wait);
738                                 if (erase->state != MTD_ERASE_DONE &&
739                                     erase->state != MTD_ERASE_FAILED)
740                                         schedule();
741                                 remove_wait_queue(&waitq, &wait);
742                                 set_current_state(TASK_RUNNING);
743 
744                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
745                         }
746                         kfree(erase);
747                 }
748                 break;
749         }
750 
751         case MEMWRITEOOB:
752         {
753                 struct mtd_oob_buf buf;
754                 struct mtd_oob_buf __user *buf_user = argp;
755 
756                 /* NOTE: writes return length to buf_user->length */
757                 if (copy_from_user(&buf, argp, sizeof(buf)))
758                         ret = -EFAULT;
759                 else
760                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
761                                 buf.ptr, &buf_user->length);
762                 break;
763         }
764 
765         case MEMREADOOB:
766         {
767                 struct mtd_oob_buf buf;
768                 struct mtd_oob_buf __user *buf_user = argp;
769 
770                 /* NOTE: writes return length to buf_user->start */
771                 if (copy_from_user(&buf, argp, sizeof(buf)))
772                         ret = -EFAULT;
773                 else
774                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
775                                 buf.ptr, &buf_user->start);
776                 break;
777         }
778 
779         case MEMWRITEOOB64:
780         {
781                 struct mtd_oob_buf64 buf;
782                 struct mtd_oob_buf64 __user *buf_user = argp;
783 
784                 if (copy_from_user(&buf, argp, sizeof(buf)))
785                         ret = -EFAULT;
786                 else
787                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
788                                 (void __user *)(uintptr_t)buf.usr_ptr,
789                                 &buf_user->length);
790                 break;
791         }
792 
793         case MEMREADOOB64:
794         {
795                 struct mtd_oob_buf64 buf;
796                 struct mtd_oob_buf64 __user *buf_user = argp;
797 
798                 if (copy_from_user(&buf, argp, sizeof(buf)))
799                         ret = -EFAULT;
800                 else
801                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
802                                 (void __user *)(uintptr_t)buf.usr_ptr,
803                                 &buf_user->length);
804                 break;
805         }
806 
807         case MEMWRITE:
808         {
809                 ret = mtdchar_write_ioctl(mtd,
810                       (struct mtd_write_req __user *)arg);
811                 break;
812         }
813 
814         case MEMLOCK:
815         {
816                 struct erase_info_user einfo;
817 
818                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
819                         return -EFAULT;
820 
821                 ret = mtd_lock(mtd, einfo.start, einfo.length);
822                 break;
823         }
824 
825         case MEMUNLOCK:
826         {
827                 struct erase_info_user einfo;
828 
829                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
830                         return -EFAULT;
831 
832                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
833                 break;
834         }
835 
836         case MEMISLOCKED:
837         {
838                 struct erase_info_user einfo;
839 
840                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
841                         return -EFAULT;
842 
843                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
844                 break;
845         }
846 
847         /* Legacy interface */
848         case MEMGETOOBSEL:
849         {
850                 struct nand_oobinfo oi;
851 
852                 if (!mtd->ecclayout)
853                         return -EOPNOTSUPP;
854                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
855                         return -EINVAL;
856 
857                 oi.useecc = MTD_NANDECC_AUTOPLACE;
858                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
859                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
860                        sizeof(oi.oobfree));
861                 oi.eccbytes = mtd->ecclayout->eccbytes;
862 
863                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
864                         return -EFAULT;
865                 break;
866         }
867 
868         case MEMGETBADBLOCK:
869         {
870                 loff_t offs;
871 
872                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
873                         return -EFAULT;
874                 return mtd_block_isbad(mtd, offs);
875                 break;
876         }
877 
878         case MEMSETBADBLOCK:
879         {
880                 loff_t offs;
881 
882                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
883                         return -EFAULT;
884                 return mtd_block_markbad(mtd, offs);
885                 break;
886         }
887 
888         case OTPSELECT:
889         {
890                 int mode;
891                 if (copy_from_user(&mode, argp, sizeof(int)))
892                         return -EFAULT;
893 
894                 mfi->mode = MTD_FILE_MODE_NORMAL;
895 
896                 ret = otp_select_filemode(mfi, mode);
897 
898                 file->f_pos = 0;
899                 break;
900         }
901 
902         case OTPGETREGIONCOUNT:
903         case OTPGETREGIONINFO:
904         {
905                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
906                 size_t retlen;
907                 if (!buf)
908                         return -ENOMEM;
909                 switch (mfi->mode) {
910                 case MTD_FILE_MODE_OTP_FACTORY:
911                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
912                         break;
913                 case MTD_FILE_MODE_OTP_USER:
914                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
915                         break;
916                 default:
917                         ret = -EINVAL;
918                         break;
919                 }
920                 if (!ret) {
921                         if (cmd == OTPGETREGIONCOUNT) {
922                                 int nbr = retlen / sizeof(struct otp_info);
923                                 ret = copy_to_user(argp, &nbr, sizeof(int));
924                         } else
925                                 ret = copy_to_user(argp, buf, retlen);
926                         if (ret)
927                                 ret = -EFAULT;
928                 }
929                 kfree(buf);
930                 break;
931         }
932 
933         case OTPLOCK:
934         {
935                 struct otp_info oinfo;
936 
937                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
938                         return -EINVAL;
939                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
940                         return -EFAULT;
941                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
942                 break;
943         }
944 
945         /* This ioctl is being deprecated - it truncates the ECC layout */
946         case ECCGETLAYOUT:
947         {
948                 struct nand_ecclayout_user *usrlay;
949 
950                 if (!mtd->ecclayout)
951                         return -EOPNOTSUPP;
952 
953                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
954                 if (!usrlay)
955                         return -ENOMEM;
956 
957                 shrink_ecclayout(mtd->ecclayout, usrlay);
958 
959                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
960                         ret = -EFAULT;
961                 kfree(usrlay);
962                 break;
963         }
964 
965         case ECCGETSTATS:
966         {
967                 if (copy_to_user(argp, &mtd->ecc_stats,
968                                  sizeof(struct mtd_ecc_stats)))
969                         return -EFAULT;
970                 break;
971         }
972 
973         case MTDFILEMODE:
974         {
975                 mfi->mode = 0;
976 
977                 switch(arg) {
978                 case MTD_FILE_MODE_OTP_FACTORY:
979                 case MTD_FILE_MODE_OTP_USER:
980                         ret = otp_select_filemode(mfi, arg);
981                         break;
982 
983                 case MTD_FILE_MODE_RAW:
984                         if (!mtd_has_oob(mtd))
985                                 return -EOPNOTSUPP;
986                         mfi->mode = arg;
987 
988                 case MTD_FILE_MODE_NORMAL:
989                         break;
990                 default:
991                         ret = -EINVAL;
992                 }
993                 file->f_pos = 0;
994                 break;
995         }
996 
997         case BLKPG:
998         {
999                 ret = mtdchar_blkpg_ioctl(mtd,
1000                       (struct blkpg_ioctl_arg __user *)arg);
1001                 break;
1002         }
1003 
1004         case BLKRRPART:
1005         {
1006                 /* No reread partition feature. Just return ok */
1007                 ret = 0;
1008                 break;
1009         }
1010 
1011         default:
1012                 ret = -ENOTTY;
1013         }
1014 
1015         return ret;
1016 } /* memory_ioctl */
1017 
1018 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1019 {
1020         int ret;
1021 
1022         mutex_lock(&mtd_mutex);
1023         ret = mtdchar_ioctl(file, cmd, arg);
1024         mutex_unlock(&mtd_mutex);
1025 
1026         return ret;
1027 }
1028 
1029 #ifdef CONFIG_COMPAT
1030 
1031 struct mtd_oob_buf32 {
1032         u_int32_t start;
1033         u_int32_t length;
1034         compat_caddr_t ptr;     /* unsigned char* */
1035 };
1036 
1037 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1038 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1039 
1040 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1041         unsigned long arg)
1042 {
1043         struct mtd_file_info *mfi = file->private_data;
1044         struct mtd_info *mtd = mfi->mtd;
1045         void __user *argp = compat_ptr(arg);
1046         int ret = 0;
1047 
1048         mutex_lock(&mtd_mutex);
1049 
1050         switch (cmd) {
1051         case MEMWRITEOOB32:
1052         {
1053                 struct mtd_oob_buf32 buf;
1054                 struct mtd_oob_buf32 __user *buf_user = argp;
1055 
1056                 if (copy_from_user(&buf, argp, sizeof(buf)))
1057                         ret = -EFAULT;
1058                 else
1059                         ret = mtdchar_writeoob(file, mtd, buf.start,
1060                                 buf.length, compat_ptr(buf.ptr),
1061                                 &buf_user->length);
1062                 break;
1063         }
1064 
1065         case MEMREADOOB32:
1066         {
1067                 struct mtd_oob_buf32 buf;
1068                 struct mtd_oob_buf32 __user *buf_user = argp;
1069 
1070                 /* NOTE: writes return length to buf->start */
1071                 if (copy_from_user(&buf, argp, sizeof(buf)))
1072                         ret = -EFAULT;
1073                 else
1074                         ret = mtdchar_readoob(file, mtd, buf.start,
1075                                 buf.length, compat_ptr(buf.ptr),
1076                                 &buf_user->start);
1077                 break;
1078         }
1079         default:
1080                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1081         }
1082 
1083         mutex_unlock(&mtd_mutex);
1084 
1085         return ret;
1086 }
1087 
1088 #endif /* CONFIG_COMPAT */
1089 
1090 /*
1091  * try to determine where a shared mapping can be made
1092  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1093  *   mappings)
1094  */
1095 #ifndef CONFIG_MMU
1096 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1097                                            unsigned long addr,
1098                                            unsigned long len,
1099                                            unsigned long pgoff,
1100                                            unsigned long flags)
1101 {
1102         struct mtd_file_info *mfi = file->private_data;
1103         struct mtd_info *mtd = mfi->mtd;
1104         unsigned long offset;
1105         int ret;
1106 
1107         if (addr != 0)
1108                 return (unsigned long) -EINVAL;
1109 
1110         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1111                 return (unsigned long) -EINVAL;
1112 
1113         offset = pgoff << PAGE_SHIFT;
1114         if (offset > mtd->size - len)
1115                 return (unsigned long) -EINVAL;
1116 
1117         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1118         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1119 }
1120 #endif
1121 
1122 /*
1123  * set up a mapping for shared memory segments
1124  */
1125 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1126 {
1127 #ifdef CONFIG_MMU
1128         struct mtd_file_info *mfi = file->private_data;
1129         struct mtd_info *mtd = mfi->mtd;
1130         struct map_info *map = mtd->priv;
1131 
1132         /* This is broken because it assumes the MTD device is map-based
1133            and that mtd->priv is a valid struct map_info.  It should be
1134            replaced with something that uses the mtd_get_unmapped_area()
1135            operation properly. */
1136         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1137 #ifdef pgprot_noncached
1138                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1139                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1140 #endif
1141                 return vm_iomap_memory(vma, map->phys, map->size);
1142         }
1143         return -ENODEV;
1144 #else
1145         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1146 #endif
1147 }
1148 
1149 static const struct file_operations mtd_fops = {
1150         .owner          = THIS_MODULE,
1151         .llseek         = mtdchar_lseek,
1152         .read           = mtdchar_read,
1153         .write          = mtdchar_write,
1154         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1155 #ifdef CONFIG_COMPAT
1156         .compat_ioctl   = mtdchar_compat_ioctl,
1157 #endif
1158         .open           = mtdchar_open,
1159         .release        = mtdchar_close,
1160         .mmap           = mtdchar_mmap,
1161 #ifndef CONFIG_MMU
1162         .get_unmapped_area = mtdchar_get_unmapped_area,
1163 #endif
1164 };
1165 
1166 static const struct super_operations mtd_ops = {
1167         .drop_inode = generic_delete_inode,
1168         .statfs = simple_statfs,
1169 };
1170 
1171 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1172                                 int flags, const char *dev_name, void *data)
1173 {
1174         return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1175 }
1176 
1177 static struct file_system_type mtd_inodefs_type = {
1178        .name = "mtd_inodefs",
1179        .mount = mtd_inodefs_mount,
1180        .kill_sb = kill_anon_super,
1181 };
1182 MODULE_ALIAS_FS("mtd_inodefs");
1183 
1184 int __init init_mtdchar(void)
1185 {
1186         int ret;
1187 
1188         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1189                                    "mtd", &mtd_fops);
1190         if (ret < 0) {
1191                 pr_err("Can't allocate major number %d for MTD\n",
1192                        MTD_CHAR_MAJOR);
1193                 return ret;
1194         }
1195 
1196         ret = register_filesystem(&mtd_inodefs_type);
1197         if (ret) {
1198                 pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1199                        ret);
1200                 goto err_unregister_chdev;
1201         }
1202 
1203         return ret;
1204 
1205 err_unregister_chdev:
1206         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1207         return ret;
1208 }
1209 
1210 void __exit cleanup_mtdchar(void)
1211 {
1212         unregister_filesystem(&mtd_inodefs_type);
1213         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1214 }
1215 
1216 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1217 

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