Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 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

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                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
553 
554         case BLKPG_DEL_PARTITION:
555 
556                 if (p.pno < 0)
557                         return -EINVAL;
558 
559                 return mtd_del_partition(mtd, p.pno);
560 
561         default:
562                 return -EINVAL;
563         }
564 }
565 
566 static int mtdchar_write_ioctl(struct mtd_info *mtd,
567                 struct mtd_write_req __user *argp)
568 {
569         struct mtd_write_req req;
570         struct mtd_oob_ops ops;
571         void __user *usr_data, *usr_oob;
572         int ret;
573 
574         if (copy_from_user(&req, argp, sizeof(req)) ||
575                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
576                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
577                 return -EFAULT;
578         if (!mtd->_write_oob)
579                 return -EOPNOTSUPP;
580 
581         ops.mode = req.mode;
582         ops.len = (size_t)req.len;
583         ops.ooblen = (size_t)req.ooblen;
584         ops.ooboffs = 0;
585 
586         usr_data = (void __user *)(uintptr_t)req.usr_data;
587         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
588 
589         if (req.usr_data) {
590                 ops.datbuf = memdup_user(usr_data, ops.len);
591                 if (IS_ERR(ops.datbuf))
592                         return PTR_ERR(ops.datbuf);
593         } else {
594                 ops.datbuf = NULL;
595         }
596 
597         if (req.usr_oob) {
598                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
599                 if (IS_ERR(ops.oobbuf)) {
600                         kfree(ops.datbuf);
601                         return PTR_ERR(ops.oobbuf);
602                 }
603         } else {
604                 ops.oobbuf = NULL;
605         }
606 
607         ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
608 
609         kfree(ops.datbuf);
610         kfree(ops.oobbuf);
611 
612         return ret;
613 }
614 
615 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
616 {
617         struct mtd_file_info *mfi = file->private_data;
618         struct mtd_info *mtd = mfi->mtd;
619         void __user *argp = (void __user *)arg;
620         int ret = 0;
621         u_long size;
622         struct mtd_info_user info;
623 
624         pr_debug("MTD_ioctl\n");
625 
626         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
627         if (cmd & IOC_IN) {
628                 if (!access_ok(VERIFY_READ, argp, size))
629                         return -EFAULT;
630         }
631         if (cmd & IOC_OUT) {
632                 if (!access_ok(VERIFY_WRITE, argp, size))
633                         return -EFAULT;
634         }
635 
636         switch (cmd) {
637         case MEMGETREGIONCOUNT:
638                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
639                         return -EFAULT;
640                 break;
641 
642         case MEMGETREGIONINFO:
643         {
644                 uint32_t ur_idx;
645                 struct mtd_erase_region_info *kr;
646                 struct region_info_user __user *ur = argp;
647 
648                 if (get_user(ur_idx, &(ur->regionindex)))
649                         return -EFAULT;
650 
651                 if (ur_idx >= mtd->numeraseregions)
652                         return -EINVAL;
653 
654                 kr = &(mtd->eraseregions[ur_idx]);
655 
656                 if (put_user(kr->offset, &(ur->offset))
657                     || put_user(kr->erasesize, &(ur->erasesize))
658                     || put_user(kr->numblocks, &(ur->numblocks)))
659                         return -EFAULT;
660 
661                 break;
662         }
663 
664         case MEMGETINFO:
665                 memset(&info, 0, sizeof(info));
666                 info.type       = mtd->type;
667                 info.flags      = mtd->flags;
668                 info.size       = mtd->size;
669                 info.erasesize  = mtd->erasesize;
670                 info.writesize  = mtd->writesize;
671                 info.oobsize    = mtd->oobsize;
672                 /* The below field is obsolete */
673                 info.padding    = 0;
674                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
675                         return -EFAULT;
676                 break;
677 
678         case MEMERASE:
679         case MEMERASE64:
680         {
681                 struct erase_info *erase;
682 
683                 if(!(file->f_mode & FMODE_WRITE))
684                         return -EPERM;
685 
686                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
687                 if (!erase)
688                         ret = -ENOMEM;
689                 else {
690                         wait_queue_head_t waitq;
691                         DECLARE_WAITQUEUE(wait, current);
692 
693                         init_waitqueue_head(&waitq);
694 
695                         if (cmd == MEMERASE64) {
696                                 struct erase_info_user64 einfo64;
697 
698                                 if (copy_from_user(&einfo64, argp,
699                                             sizeof(struct erase_info_user64))) {
700                                         kfree(erase);
701                                         return -EFAULT;
702                                 }
703                                 erase->addr = einfo64.start;
704                                 erase->len = einfo64.length;
705                         } else {
706                                 struct erase_info_user einfo32;
707 
708                                 if (copy_from_user(&einfo32, argp,
709                                             sizeof(struct erase_info_user))) {
710                                         kfree(erase);
711                                         return -EFAULT;
712                                 }
713                                 erase->addr = einfo32.start;
714                                 erase->len = einfo32.length;
715                         }
716                         erase->mtd = mtd;
717                         erase->callback = mtdchar_erase_callback;
718                         erase->priv = (unsigned long)&waitq;
719 
720                         /*
721                           FIXME: Allow INTERRUPTIBLE. Which means
722                           not having the wait_queue head on the stack.
723 
724                           If the wq_head is on the stack, and we
725                           leave because we got interrupted, then the
726                           wq_head is no longer there when the
727                           callback routine tries to wake us up.
728                         */
729                         ret = mtd_erase(mtd, erase);
730                         if (!ret) {
731                                 set_current_state(TASK_UNINTERRUPTIBLE);
732                                 add_wait_queue(&waitq, &wait);
733                                 if (erase->state != MTD_ERASE_DONE &&
734                                     erase->state != MTD_ERASE_FAILED)
735                                         schedule();
736                                 remove_wait_queue(&waitq, &wait);
737                                 set_current_state(TASK_RUNNING);
738 
739                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
740                         }
741                         kfree(erase);
742                 }
743                 break;
744         }
745 
746         case MEMWRITEOOB:
747         {
748                 struct mtd_oob_buf buf;
749                 struct mtd_oob_buf __user *buf_user = argp;
750 
751                 /* NOTE: writes return length to buf_user->length */
752                 if (copy_from_user(&buf, argp, sizeof(buf)))
753                         ret = -EFAULT;
754                 else
755                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
756                                 buf.ptr, &buf_user->length);
757                 break;
758         }
759 
760         case MEMREADOOB:
761         {
762                 struct mtd_oob_buf buf;
763                 struct mtd_oob_buf __user *buf_user = argp;
764 
765                 /* NOTE: writes return length to buf_user->start */
766                 if (copy_from_user(&buf, argp, sizeof(buf)))
767                         ret = -EFAULT;
768                 else
769                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
770                                 buf.ptr, &buf_user->start);
771                 break;
772         }
773 
774         case MEMWRITEOOB64:
775         {
776                 struct mtd_oob_buf64 buf;
777                 struct mtd_oob_buf64 __user *buf_user = argp;
778 
779                 if (copy_from_user(&buf, argp, sizeof(buf)))
780                         ret = -EFAULT;
781                 else
782                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
783                                 (void __user *)(uintptr_t)buf.usr_ptr,
784                                 &buf_user->length);
785                 break;
786         }
787 
788         case MEMREADOOB64:
789         {
790                 struct mtd_oob_buf64 buf;
791                 struct mtd_oob_buf64 __user *buf_user = argp;
792 
793                 if (copy_from_user(&buf, argp, sizeof(buf)))
794                         ret = -EFAULT;
795                 else
796                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
797                                 (void __user *)(uintptr_t)buf.usr_ptr,
798                                 &buf_user->length);
799                 break;
800         }
801 
802         case MEMWRITE:
803         {
804                 ret = mtdchar_write_ioctl(mtd,
805                       (struct mtd_write_req __user *)arg);
806                 break;
807         }
808 
809         case MEMLOCK:
810         {
811                 struct erase_info_user einfo;
812 
813                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
814                         return -EFAULT;
815 
816                 ret = mtd_lock(mtd, einfo.start, einfo.length);
817                 break;
818         }
819 
820         case MEMUNLOCK:
821         {
822                 struct erase_info_user einfo;
823 
824                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
825                         return -EFAULT;
826 
827                 ret = mtd_unlock(mtd, einfo.start, einfo.length);
828                 break;
829         }
830 
831         case MEMISLOCKED:
832         {
833                 struct erase_info_user einfo;
834 
835                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
836                         return -EFAULT;
837 
838                 ret = mtd_is_locked(mtd, einfo.start, einfo.length);
839                 break;
840         }
841 
842         /* Legacy interface */
843         case MEMGETOOBSEL:
844         {
845                 struct nand_oobinfo oi;
846 
847                 if (!mtd->ecclayout)
848                         return -EOPNOTSUPP;
849                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
850                         return -EINVAL;
851 
852                 oi.useecc = MTD_NANDECC_AUTOPLACE;
853                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
854                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
855                        sizeof(oi.oobfree));
856                 oi.eccbytes = mtd->ecclayout->eccbytes;
857 
858                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
859                         return -EFAULT;
860                 break;
861         }
862 
863         case MEMGETBADBLOCK:
864         {
865                 loff_t offs;
866 
867                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
868                         return -EFAULT;
869                 return mtd_block_isbad(mtd, offs);
870                 break;
871         }
872 
873         case MEMSETBADBLOCK:
874         {
875                 loff_t offs;
876 
877                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
878                         return -EFAULT;
879                 return mtd_block_markbad(mtd, offs);
880                 break;
881         }
882 
883         case OTPSELECT:
884         {
885                 int mode;
886                 if (copy_from_user(&mode, argp, sizeof(int)))
887                         return -EFAULT;
888 
889                 mfi->mode = MTD_FILE_MODE_NORMAL;
890 
891                 ret = otp_select_filemode(mfi, mode);
892 
893                 file->f_pos = 0;
894                 break;
895         }
896 
897         case OTPGETREGIONCOUNT:
898         case OTPGETREGIONINFO:
899         {
900                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
901                 size_t retlen;
902                 if (!buf)
903                         return -ENOMEM;
904                 switch (mfi->mode) {
905                 case MTD_FILE_MODE_OTP_FACTORY:
906                         ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
907                         break;
908                 case MTD_FILE_MODE_OTP_USER:
909                         ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
910                         break;
911                 default:
912                         ret = -EINVAL;
913                         break;
914                 }
915                 if (!ret) {
916                         if (cmd == OTPGETREGIONCOUNT) {
917                                 int nbr = retlen / sizeof(struct otp_info);
918                                 ret = copy_to_user(argp, &nbr, sizeof(int));
919                         } else
920                                 ret = copy_to_user(argp, buf, retlen);
921                         if (ret)
922                                 ret = -EFAULT;
923                 }
924                 kfree(buf);
925                 break;
926         }
927 
928         case OTPLOCK:
929         {
930                 struct otp_info oinfo;
931 
932                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
933                         return -EINVAL;
934                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
935                         return -EFAULT;
936                 ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
937                 break;
938         }
939 
940         /* This ioctl is being deprecated - it truncates the ECC layout */
941         case ECCGETLAYOUT:
942         {
943                 struct nand_ecclayout_user *usrlay;
944 
945                 if (!mtd->ecclayout)
946                         return -EOPNOTSUPP;
947 
948                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
949                 if (!usrlay)
950                         return -ENOMEM;
951 
952                 shrink_ecclayout(mtd->ecclayout, usrlay);
953 
954                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
955                         ret = -EFAULT;
956                 kfree(usrlay);
957                 break;
958         }
959 
960         case ECCGETSTATS:
961         {
962                 if (copy_to_user(argp, &mtd->ecc_stats,
963                                  sizeof(struct mtd_ecc_stats)))
964                         return -EFAULT;
965                 break;
966         }
967 
968         case MTDFILEMODE:
969         {
970                 mfi->mode = 0;
971 
972                 switch(arg) {
973                 case MTD_FILE_MODE_OTP_FACTORY:
974                 case MTD_FILE_MODE_OTP_USER:
975                         ret = otp_select_filemode(mfi, arg);
976                         break;
977 
978                 case MTD_FILE_MODE_RAW:
979                         if (!mtd_has_oob(mtd))
980                                 return -EOPNOTSUPP;
981                         mfi->mode = arg;
982 
983                 case MTD_FILE_MODE_NORMAL:
984                         break;
985                 default:
986                         ret = -EINVAL;
987                 }
988                 file->f_pos = 0;
989                 break;
990         }
991 
992         case BLKPG:
993         {
994                 ret = mtdchar_blkpg_ioctl(mtd,
995                       (struct blkpg_ioctl_arg __user *)arg);
996                 break;
997         }
998 
999         case BLKRRPART:
1000         {
1001                 /* No reread partition feature. Just return ok */
1002                 ret = 0;
1003                 break;
1004         }
1005 
1006         default:
1007                 ret = -ENOTTY;
1008         }
1009 
1010         return ret;
1011 } /* memory_ioctl */
1012 
1013 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1014 {
1015         int ret;
1016 
1017         mutex_lock(&mtd_mutex);
1018         ret = mtdchar_ioctl(file, cmd, arg);
1019         mutex_unlock(&mtd_mutex);
1020 
1021         return ret;
1022 }
1023 
1024 #ifdef CONFIG_COMPAT
1025 
1026 struct mtd_oob_buf32 {
1027         u_int32_t start;
1028         u_int32_t length;
1029         compat_caddr_t ptr;     /* unsigned char* */
1030 };
1031 
1032 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1033 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1034 
1035 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1036         unsigned long arg)
1037 {
1038         struct mtd_file_info *mfi = file->private_data;
1039         struct mtd_info *mtd = mfi->mtd;
1040         void __user *argp = compat_ptr(arg);
1041         int ret = 0;
1042 
1043         mutex_lock(&mtd_mutex);
1044 
1045         switch (cmd) {
1046         case MEMWRITEOOB32:
1047         {
1048                 struct mtd_oob_buf32 buf;
1049                 struct mtd_oob_buf32 __user *buf_user = argp;
1050 
1051                 if (copy_from_user(&buf, argp, sizeof(buf)))
1052                         ret = -EFAULT;
1053                 else
1054                         ret = mtdchar_writeoob(file, mtd, buf.start,
1055                                 buf.length, compat_ptr(buf.ptr),
1056                                 &buf_user->length);
1057                 break;
1058         }
1059 
1060         case MEMREADOOB32:
1061         {
1062                 struct mtd_oob_buf32 buf;
1063                 struct mtd_oob_buf32 __user *buf_user = argp;
1064 
1065                 /* NOTE: writes return length to buf->start */
1066                 if (copy_from_user(&buf, argp, sizeof(buf)))
1067                         ret = -EFAULT;
1068                 else
1069                         ret = mtdchar_readoob(file, mtd, buf.start,
1070                                 buf.length, compat_ptr(buf.ptr),
1071                                 &buf_user->start);
1072                 break;
1073         }
1074         default:
1075                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1076         }
1077 
1078         mutex_unlock(&mtd_mutex);
1079 
1080         return ret;
1081 }
1082 
1083 #endif /* CONFIG_COMPAT */
1084 
1085 /*
1086  * try to determine where a shared mapping can be made
1087  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1088  *   mappings)
1089  */
1090 #ifndef CONFIG_MMU
1091 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1092                                            unsigned long addr,
1093                                            unsigned long len,
1094                                            unsigned long pgoff,
1095                                            unsigned long flags)
1096 {
1097         struct mtd_file_info *mfi = file->private_data;
1098         struct mtd_info *mtd = mfi->mtd;
1099         unsigned long offset;
1100         int ret;
1101 
1102         if (addr != 0)
1103                 return (unsigned long) -EINVAL;
1104 
1105         if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1106                 return (unsigned long) -EINVAL;
1107 
1108         offset = pgoff << PAGE_SHIFT;
1109         if (offset > mtd->size - len)
1110                 return (unsigned long) -EINVAL;
1111 
1112         ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1113         return ret == -EOPNOTSUPP ? -ENODEV : ret;
1114 }
1115 #endif
1116 
1117 /*
1118  * set up a mapping for shared memory segments
1119  */
1120 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1121 {
1122 #ifdef CONFIG_MMU
1123         struct mtd_file_info *mfi = file->private_data;
1124         struct mtd_info *mtd = mfi->mtd;
1125         struct map_info *map = mtd->priv;
1126 
1127         /* This is broken because it assumes the MTD device is map-based
1128            and that mtd->priv is a valid struct map_info.  It should be
1129            replaced with something that uses the mtd_get_unmapped_area()
1130            operation properly. */
1131         if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1132 #ifdef pgprot_noncached
1133                 if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1134                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1135 #endif
1136                 return vm_iomap_memory(vma, map->phys, map->size);
1137         }
1138         return -ENODEV;
1139 #else
1140         return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1141 #endif
1142 }
1143 
1144 static const struct file_operations mtd_fops = {
1145         .owner          = THIS_MODULE,
1146         .llseek         = mtdchar_lseek,
1147         .read           = mtdchar_read,
1148         .write          = mtdchar_write,
1149         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1150 #ifdef CONFIG_COMPAT
1151         .compat_ioctl   = mtdchar_compat_ioctl,
1152 #endif
1153         .open           = mtdchar_open,
1154         .release        = mtdchar_close,
1155         .mmap           = mtdchar_mmap,
1156 #ifndef CONFIG_MMU
1157         .get_unmapped_area = mtdchar_get_unmapped_area,
1158 #endif
1159 };
1160 
1161 static const struct super_operations mtd_ops = {
1162         .drop_inode = generic_delete_inode,
1163         .statfs = simple_statfs,
1164 };
1165 
1166 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1167                                 int flags, const char *dev_name, void *data)
1168 {
1169         return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1170 }
1171 
1172 static struct file_system_type mtd_inodefs_type = {
1173        .name = "mtd_inodefs",
1174        .mount = mtd_inodefs_mount,
1175        .kill_sb = kill_anon_super,
1176 };
1177 MODULE_ALIAS_FS("mtd_inodefs");
1178 
1179 int __init init_mtdchar(void)
1180 {
1181         int ret;
1182 
1183         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1184                                    "mtd", &mtd_fops);
1185         if (ret < 0) {
1186                 pr_err("Can't allocate major number %d for MTD\n",
1187                        MTD_CHAR_MAJOR);
1188                 return ret;
1189         }
1190 
1191         ret = register_filesystem(&mtd_inodefs_type);
1192         if (ret) {
1193                 pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1194                        ret);
1195                 goto err_unregister_chdev;
1196         }
1197 
1198         return ret;
1199 
1200 err_unregister_chdev:
1201         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1202         return ret;
1203 }
1204 
1205 void __exit cleanup_mtdchar(void)
1206 {
1207         unregister_filesystem(&mtd_inodefs_type);
1208         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1209 }
1210 
1211 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1212 

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