V4L/DVB (8613): v4l: move BKL down to the driver level.
[linux-2.6] / drivers / ide / ide-proc.c
1 /*
2  *  Copyright (C) 1997-1998     Mark Lord
3  *  Copyright (C) 2003          Red Hat <alan@redhat.com>
4  *
5  *  Some code was moved here from ide.c, see it for original copyrights.
6  */
7
8 /*
9  * This is the /proc/ide/ filesystem implementation.
10  *
11  * Drive/Driver settings can be retrieved by reading the drive's
12  * "settings" files.  e.g.    "cat /proc/ide0/hda/settings"
13  * To write a new value "val" into a specific setting "name", use:
14  *   echo "name:val" >/proc/ide/ide0/hda/settings
15  */
16
17 #include <linux/module.h>
18
19 #include <asm/uaccess.h>
20 #include <linux/errno.h>
21 #include <linux/proc_fs.h>
22 #include <linux/stat.h>
23 #include <linux/mm.h>
24 #include <linux/pci.h>
25 #include <linux/ctype.h>
26 #include <linux/ide.h>
27 #include <linux/seq_file.h>
28
29 #include <asm/io.h>
30
31 static struct proc_dir_entry *proc_ide_root;
32
33 static int proc_ide_read_imodel
34         (char *page, char **start, off_t off, int count, int *eof, void *data)
35 {
36         ide_hwif_t      *hwif = (ide_hwif_t *) data;
37         int             len;
38         const char      *name;
39
40         switch (hwif->chipset) {
41         case ide_generic:       name = "generic";       break;
42         case ide_pci:           name = "pci";           break;
43         case ide_cmd640:        name = "cmd640";        break;
44         case ide_dtc2278:       name = "dtc2278";       break;
45         case ide_ali14xx:       name = "ali14xx";       break;
46         case ide_qd65xx:        name = "qd65xx";        break;
47         case ide_umc8672:       name = "umc8672";       break;
48         case ide_ht6560b:       name = "ht6560b";       break;
49         case ide_rz1000:        name = "rz1000";        break;
50         case ide_trm290:        name = "trm290";        break;
51         case ide_cmd646:        name = "cmd646";        break;
52         case ide_cy82c693:      name = "cy82c693";      break;
53         case ide_4drives:       name = "4drives";       break;
54         case ide_pmac:          name = "mac-io";        break;
55         case ide_au1xxx:        name = "au1xxx";        break;
56         case ide_palm3710:      name = "palm3710";      break;
57         case ide_acorn:         name = "acorn";         break;
58         default:                name = "(unknown)";     break;
59         }
60         len = sprintf(page, "%s\n", name);
61         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
62 }
63
64 static int proc_ide_read_mate
65         (char *page, char **start, off_t off, int count, int *eof, void *data)
66 {
67         ide_hwif_t      *hwif = (ide_hwif_t *) data;
68         int             len;
69
70         if (hwif && hwif->mate)
71                 len = sprintf(page, "%s\n", hwif->mate->name);
72         else
73                 len = sprintf(page, "(none)\n");
74         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
75 }
76
77 static int proc_ide_read_channel
78         (char *page, char **start, off_t off, int count, int *eof, void *data)
79 {
80         ide_hwif_t      *hwif = (ide_hwif_t *) data;
81         int             len;
82
83         page[0] = hwif->channel ? '1' : '0';
84         page[1] = '\n';
85         len = 2;
86         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
87 }
88
89 static int proc_ide_read_identify
90         (char *page, char **start, off_t off, int count, int *eof, void *data)
91 {
92         ide_drive_t     *drive = (ide_drive_t *)data;
93         int             len = 0, i = 0;
94         int             err = 0;
95
96         len = sprintf(page, "\n");
97
98         if (drive) {
99                 __le16 *val = (__le16 *)page;
100
101                 err = taskfile_lib_get_identify(drive, page);
102                 if (!err) {
103                         char *out = (char *)page + SECTOR_SIZE;
104
105                         page = out;
106                         do {
107                                 out += sprintf(out, "%04x%c",
108                                         le16_to_cpup(val), (++i & 7) ? ' ' : '\n');
109                                 val += 1;
110                         } while (i < SECTOR_SIZE / 2);
111                         len = out - page;
112                 }
113         }
114         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
115 }
116
117 /**
118  *      ide_find_setting        -       find a specific setting
119  *      @st: setting table pointer
120  *      @name: setting name
121  *
122  *      Scan's the setting table for a matching entry and returns
123  *      this or NULL if no entry is found. The caller must hold the
124  *      setting semaphore
125  */
126
127 static
128 const struct ide_proc_devset *ide_find_setting(const struct ide_proc_devset *st,
129                                                char *name)
130 {
131         while (st->name) {
132                 if (strcmp(st->name, name) == 0)
133                         break;
134                 st++;
135         }
136         return st->name ? st : NULL;
137 }
138
139 /**
140  *      ide_read_setting        -       read an IDE setting
141  *      @drive: drive to read from
142  *      @setting: drive setting
143  *
144  *      Read a drive setting and return the value. The caller
145  *      must hold the ide_setting_mtx when making this call.
146  *
147  *      BUGS: the data return and error are the same return value
148  *      so an error -EINVAL and true return of the same value cannot
149  *      be told apart
150  */
151
152 static int ide_read_setting(ide_drive_t *drive,
153                             const struct ide_proc_devset *setting)
154 {
155         const struct ide_devset *ds = setting->setting;
156         int val = -EINVAL;
157
158         if (ds->get) {
159                 unsigned long flags;
160
161                 spin_lock_irqsave(&ide_lock, flags);
162                 val = ds->get(drive);
163                 spin_unlock_irqrestore(&ide_lock, flags);
164         }
165
166         return val;
167 }
168
169 /**
170  *      ide_write_setting       -       read an IDE setting
171  *      @drive: drive to read from
172  *      @setting: drive setting
173  *      @val: value
174  *
175  *      Write a drive setting if it is possible. The caller
176  *      must hold the ide_setting_mtx when making this call.
177  *
178  *      BUGS: the data return and error are the same return value
179  *      so an error -EINVAL and true return of the same value cannot
180  *      be told apart
181  *
182  *      FIXME:  This should be changed to enqueue a special request
183  *      to the driver to change settings, and then wait on a sema for completion.
184  *      The current scheme of polling is kludgy, though safe enough.
185  */
186
187 static int ide_write_setting(ide_drive_t *drive,
188                              const struct ide_proc_devset *setting, int val)
189 {
190         const struct ide_devset *ds = setting->setting;
191
192         if (!capable(CAP_SYS_ADMIN))
193                 return -EACCES;
194         if (!ds->set)
195                 return -EPERM;
196         if ((ds->flags & DS_SYNC)
197             && (val < setting->min || val > setting->max))
198                 return -EINVAL;
199         return ide_devset_execute(drive, ds, val);
200 }
201
202 ide_devset_get(xfer_rate, current_speed);
203
204 static int set_xfer_rate (ide_drive_t *drive, int arg)
205 {
206         ide_task_t task;
207         int err;
208
209         if (arg < XFER_PIO_0 || arg > XFER_UDMA_6)
210                 return -EINVAL;
211
212         memset(&task, 0, sizeof(task));
213         task.tf.command = ATA_CMD_SET_FEATURES;
214         task.tf.feature = SETFEATURES_XFER;
215         task.tf.nsect   = (u8)arg;
216         task.tf_flags = IDE_TFLAG_OUT_FEATURE | IDE_TFLAG_OUT_NSECT |
217                         IDE_TFLAG_IN_NSECT;
218
219         err = ide_no_data_taskfile(drive, &task);
220
221         if (!err) {
222                 ide_set_xfer_rate(drive, (u8) arg);
223                 ide_driveid_update(drive);
224         }
225         return err;
226 }
227
228 ide_devset_rw(current_speed, xfer_rate);
229 ide_devset_rw_field(init_speed, init_speed);
230 ide_devset_rw_field(nice1, nice1);
231 ide_devset_rw_field(number, dn);
232
233 static const struct ide_proc_devset ide_generic_settings[] = {
234         IDE_PROC_DEVSET(current_speed, 0, 70),
235         IDE_PROC_DEVSET(init_speed, 0, 70),
236         IDE_PROC_DEVSET(io_32bit,  0, 1 + (SUPPORT_VLB_SYNC << 1)),
237         IDE_PROC_DEVSET(keepsettings, 0, 1),
238         IDE_PROC_DEVSET(nice1, 0, 1),
239         IDE_PROC_DEVSET(number, 0, 3),
240         IDE_PROC_DEVSET(pio_mode, 0, 255),
241         IDE_PROC_DEVSET(unmaskirq, 0, 1),
242         IDE_PROC_DEVSET(using_dma, 0, 1),
243         { 0 },
244 };
245
246 static void proc_ide_settings_warn(void)
247 {
248         static int warned;
249
250         if (warned)
251                 return;
252
253         printk(KERN_WARNING "Warning: /proc/ide/hd?/settings interface is "
254                             "obsolete, and will be removed soon!\n");
255         warned = 1;
256 }
257
258 static int proc_ide_read_settings
259         (char *page, char **start, off_t off, int count, int *eof, void *data)
260 {
261         const struct ide_proc_devset *setting, *g, *d;
262         const struct ide_devset *ds;
263         ide_drive_t     *drive = (ide_drive_t *) data;
264         char            *out = page;
265         int             len, rc, mul_factor, div_factor;
266
267         proc_ide_settings_warn();
268
269         mutex_lock(&ide_setting_mtx);
270         g = ide_generic_settings;
271         d = drive->settings;
272         out += sprintf(out, "name\t\t\tvalue\t\tmin\t\tmax\t\tmode\n");
273         out += sprintf(out, "----\t\t\t-----\t\t---\t\t---\t\t----\n");
274         while (g->name || (d && d->name)) {
275                 /* read settings in the alphabetical order */
276                 if (g->name && d && d->name) {
277                         if (strcmp(d->name, g->name) < 0)
278                                 setting = d++;
279                         else
280                                 setting = g++;
281                 } else if (d && d->name) {
282                         setting = d++;
283                 } else
284                         setting = g++;
285                 mul_factor = setting->mulf ? setting->mulf(drive) : 1;
286                 div_factor = setting->divf ? setting->divf(drive) : 1;
287                 out += sprintf(out, "%-24s", setting->name);
288                 rc = ide_read_setting(drive, setting);
289                 if (rc >= 0)
290                         out += sprintf(out, "%-16d", rc * mul_factor / div_factor);
291                 else
292                         out += sprintf(out, "%-16s", "write-only");
293                 out += sprintf(out, "%-16d%-16d", (setting->min * mul_factor + div_factor - 1) / div_factor, setting->max * mul_factor / div_factor);
294                 ds = setting->setting;
295                 if (ds->get)
296                         out += sprintf(out, "r");
297                 if (ds->set)
298                         out += sprintf(out, "w");
299                 out += sprintf(out, "\n");
300         }
301         len = out - page;
302         mutex_unlock(&ide_setting_mtx);
303         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
304 }
305
306 #define MAX_LEN 30
307
308 static int proc_ide_write_settings(struct file *file, const char __user *buffer,
309                                    unsigned long count, void *data)
310 {
311         ide_drive_t     *drive = (ide_drive_t *) data;
312         char            name[MAX_LEN + 1];
313         int             for_real = 0, mul_factor, div_factor;
314         unsigned long   n;
315
316         const struct ide_proc_devset *setting;
317         char *buf, *s;
318
319         if (!capable(CAP_SYS_ADMIN))
320                 return -EACCES;
321
322         proc_ide_settings_warn();
323
324         if (count >= PAGE_SIZE)
325                 return -EINVAL;
326
327         s = buf = (char *)__get_free_page(GFP_USER);
328         if (!buf)
329                 return -ENOMEM;
330
331         if (copy_from_user(buf, buffer, count)) {
332                 free_page((unsigned long)buf);
333                 return -EFAULT;
334         }
335
336         buf[count] = '\0';
337
338         /*
339          * Skip over leading whitespace
340          */
341         while (count && isspace(*s)) {
342                 --count;
343                 ++s;
344         }
345         /*
346          * Do one full pass to verify all parameters,
347          * then do another to actually write the new settings.
348          */
349         do {
350                 char *p = s;
351                 n = count;
352                 while (n > 0) {
353                         unsigned val;
354                         char *q = p;
355
356                         while (n > 0 && *p != ':') {
357                                 --n;
358                                 p++;
359                         }
360                         if (*p != ':')
361                                 goto parse_error;
362                         if (p - q > MAX_LEN)
363                                 goto parse_error;
364                         memcpy(name, q, p - q);
365                         name[p - q] = 0;
366
367                         if (n > 0) {
368                                 --n;
369                                 p++;
370                         } else
371                                 goto parse_error;
372
373                         val = simple_strtoul(p, &q, 10);
374                         n -= q - p;
375                         p = q;
376                         if (n > 0 && !isspace(*p))
377                                 goto parse_error;
378                         while (n > 0 && isspace(*p)) {
379                                 --n;
380                                 ++p;
381                         }
382
383                         mutex_lock(&ide_setting_mtx);
384                         /* generic settings first, then driver specific ones */
385                         setting = ide_find_setting(ide_generic_settings, name);
386                         if (!setting) {
387                                 if (drive->settings)
388                                         setting = ide_find_setting(drive->settings, name);
389                                 if (!setting) {
390                                         mutex_unlock(&ide_setting_mtx);
391                                         goto parse_error;
392                                 }
393                         }
394                         if (for_real) {
395                                 mul_factor = setting->mulf ? setting->mulf(drive) : 1;
396                                 div_factor = setting->divf ? setting->divf(drive) : 1;
397                                 ide_write_setting(drive, setting, val * div_factor / mul_factor);
398                         }
399                         mutex_unlock(&ide_setting_mtx);
400                 }
401         } while (!for_real++);
402         free_page((unsigned long)buf);
403         return count;
404 parse_error:
405         free_page((unsigned long)buf);
406         printk("proc_ide_write_settings(): parse error\n");
407         return -EINVAL;
408 }
409
410 int proc_ide_read_capacity
411         (char *page, char **start, off_t off, int count, int *eof, void *data)
412 {
413         int len = sprintf(page, "%llu\n", (long long)0x7fffffff);
414         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
415 }
416
417 EXPORT_SYMBOL_GPL(proc_ide_read_capacity);
418
419 int proc_ide_read_geometry
420         (char *page, char **start, off_t off, int count, int *eof, void *data)
421 {
422         ide_drive_t     *drive = (ide_drive_t *) data;
423         char            *out = page;
424         int             len;
425
426         out += sprintf(out, "physical     %d/%d/%d\n",
427                         drive->cyl, drive->head, drive->sect);
428         out += sprintf(out, "logical      %d/%d/%d\n",
429                         drive->bios_cyl, drive->bios_head, drive->bios_sect);
430
431         len = out - page;
432         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
433 }
434
435 EXPORT_SYMBOL(proc_ide_read_geometry);
436
437 static int proc_ide_read_dmodel
438         (char *page, char **start, off_t off, int count, int *eof, void *data)
439 {
440         ide_drive_t     *drive = (ide_drive_t *) data;
441         char            *m = (char *)&drive->id[ATA_ID_PROD];
442         int             len;
443
444         len = sprintf(page, "%.40s\n", m[0] ? m : "(none)");
445         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
446 }
447
448 static int proc_ide_read_driver
449         (char *page, char **start, off_t off, int count, int *eof, void *data)
450 {
451         ide_drive_t     *drive = (ide_drive_t *) data;
452         struct device   *dev = &drive->gendev;
453         ide_driver_t    *ide_drv;
454         int             len;
455
456         if (dev->driver) {
457                 ide_drv = container_of(dev->driver, ide_driver_t, gen_driver);
458                 len = sprintf(page, "%s version %s\n",
459                                 dev->driver->name, ide_drv->version);
460         } else
461                 len = sprintf(page, "ide-default version 0.9.newide\n");
462         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
463 }
464
465 static int ide_replace_subdriver(ide_drive_t *drive, const char *driver)
466 {
467         struct device *dev = &drive->gendev;
468         int ret = 1;
469         int err;
470
471         device_release_driver(dev);
472         /* FIXME: device can still be in use by previous driver */
473         strlcpy(drive->driver_req, driver, sizeof(drive->driver_req));
474         err = device_attach(dev);
475         if (err < 0)
476                 printk(KERN_WARNING "IDE: %s: device_attach error: %d\n",
477                         __func__, err);
478         drive->driver_req[0] = 0;
479         if (dev->driver == NULL) {
480                 err = device_attach(dev);
481                 if (err < 0)
482                         printk(KERN_WARNING
483                                 "IDE: %s: device_attach(2) error: %d\n",
484                                 __func__, err);
485         }
486         if (dev->driver && !strcmp(dev->driver->name, driver))
487                 ret = 0;
488
489         return ret;
490 }
491
492 static int proc_ide_write_driver
493         (struct file *file, const char __user *buffer, unsigned long count, void *data)
494 {
495         ide_drive_t     *drive = (ide_drive_t *) data;
496         char name[32];
497
498         if (!capable(CAP_SYS_ADMIN))
499                 return -EACCES;
500         if (count > 31)
501                 count = 31;
502         if (copy_from_user(name, buffer, count))
503                 return -EFAULT;
504         name[count] = '\0';
505         if (ide_replace_subdriver(drive, name))
506                 return -EINVAL;
507         return count;
508 }
509
510 static int proc_ide_read_media
511         (char *page, char **start, off_t off, int count, int *eof, void *data)
512 {
513         ide_drive_t     *drive = (ide_drive_t *) data;
514         const char      *media;
515         int             len;
516
517         switch (drive->media) {
518         case ide_disk:          media = "disk\n";       break;
519         case ide_cdrom:         media = "cdrom\n";      break;
520         case ide_tape:          media = "tape\n";       break;
521         case ide_floppy:        media = "floppy\n";     break;
522         case ide_optical:       media = "optical\n";    break;
523         default:                media = "UNKNOWN\n";    break;
524         }
525         strcpy(page, media);
526         len = strlen(media);
527         PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
528 }
529
530 static ide_proc_entry_t generic_drive_entries[] = {
531         { "driver",     S_IFREG|S_IRUGO,         proc_ide_read_driver,
532                                                  proc_ide_write_driver },
533         { "identify",   S_IFREG|S_IRUSR,         proc_ide_read_identify, NULL },
534         { "media",      S_IFREG|S_IRUGO,         proc_ide_read_media,    NULL },
535         { "model",      S_IFREG|S_IRUGO,         proc_ide_read_dmodel,   NULL },
536         { "settings",   S_IFREG|S_IRUSR|S_IWUSR, proc_ide_read_settings,
537                                                  proc_ide_write_settings },
538         { NULL, 0, NULL, NULL }
539 };
540
541 static void ide_add_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p, void *data)
542 {
543         struct proc_dir_entry *ent;
544
545         if (!dir || !p)
546                 return;
547         while (p->name != NULL) {
548                 ent = create_proc_entry(p->name, p->mode, dir);
549                 if (!ent) return;
550                 ent->data = data;
551                 ent->read_proc = p->read_proc;
552                 ent->write_proc = p->write_proc;
553                 p++;
554         }
555 }
556
557 static void ide_remove_proc_entries(struct proc_dir_entry *dir, ide_proc_entry_t *p)
558 {
559         if (!dir || !p)
560                 return;
561         while (p->name != NULL) {
562                 remove_proc_entry(p->name, dir);
563                 p++;
564         }
565 }
566
567 void ide_proc_register_driver(ide_drive_t *drive, ide_driver_t *driver)
568 {
569         mutex_lock(&ide_setting_mtx);
570         drive->settings = driver->settings;
571         mutex_unlock(&ide_setting_mtx);
572
573         ide_add_proc_entries(drive->proc, driver->proc, drive);
574 }
575
576 EXPORT_SYMBOL(ide_proc_register_driver);
577
578 /**
579  *      ide_proc_unregister_driver      -       remove driver specific data
580  *      @drive: drive
581  *      @driver: driver
582  *
583  *      Clean up the driver specific /proc files and IDE settings
584  *      for a given drive.
585  *
586  *      Takes ide_setting_mtx and ide_lock.
587  *      Caller must hold none of the locks.
588  */
589
590 void ide_proc_unregister_driver(ide_drive_t *drive, ide_driver_t *driver)
591 {
592         unsigned long flags;
593
594         ide_remove_proc_entries(drive->proc, driver->proc);
595
596         mutex_lock(&ide_setting_mtx);
597         spin_lock_irqsave(&ide_lock, flags);
598         /*
599          * ide_setting_mtx protects the settings list
600          * ide_lock protects the use of settings
601          *
602          * so we need to hold both, ide_settings_sem because we want to
603          * modify the settings list, and ide_lock because we cannot take
604          * a setting out that is being used.
605          *
606          * OTOH both ide_{read,write}_setting are only ever used under
607          * ide_setting_mtx.
608          */
609         drive->settings = NULL;
610         spin_unlock_irqrestore(&ide_lock, flags);
611         mutex_unlock(&ide_setting_mtx);
612 }
613 EXPORT_SYMBOL(ide_proc_unregister_driver);
614
615 void ide_proc_port_register_devices(ide_hwif_t *hwif)
616 {
617         int     d;
618         struct proc_dir_entry *ent;
619         struct proc_dir_entry *parent = hwif->proc;
620         char name[64];
621
622         for (d = 0; d < MAX_DRIVES; d++) {
623                 ide_drive_t *drive = &hwif->drives[d];
624
625                 if (!drive->present)
626                         continue;
627                 if (drive->proc)
628                         continue;
629
630                 drive->proc = proc_mkdir(drive->name, parent);
631                 if (drive->proc)
632                         ide_add_proc_entries(drive->proc, generic_drive_entries, drive);
633                 sprintf(name, "ide%d/%s", (drive->name[2]-'a')/2, drive->name);
634                 ent = proc_symlink(drive->name, proc_ide_root, name);
635                 if (!ent) return;
636         }
637 }
638
639 void ide_proc_unregister_device(ide_drive_t *drive)
640 {
641         if (drive->proc) {
642                 ide_remove_proc_entries(drive->proc, generic_drive_entries);
643                 remove_proc_entry(drive->name, proc_ide_root);
644                 remove_proc_entry(drive->name, drive->hwif->proc);
645                 drive->proc = NULL;
646         }
647 }
648
649 static ide_proc_entry_t hwif_entries[] = {
650         { "channel",    S_IFREG|S_IRUGO,        proc_ide_read_channel,  NULL },
651         { "mate",       S_IFREG|S_IRUGO,        proc_ide_read_mate,     NULL },
652         { "model",      S_IFREG|S_IRUGO,        proc_ide_read_imodel,   NULL },
653         { NULL, 0, NULL, NULL }
654 };
655
656 void ide_proc_register_port(ide_hwif_t *hwif)
657 {
658         if (!hwif->proc) {
659                 hwif->proc = proc_mkdir(hwif->name, proc_ide_root);
660
661                 if (!hwif->proc)
662                         return;
663
664                 ide_add_proc_entries(hwif->proc, hwif_entries, hwif);
665         }
666 }
667
668 void ide_proc_unregister_port(ide_hwif_t *hwif)
669 {
670         if (hwif->proc) {
671                 ide_remove_proc_entries(hwif->proc, hwif_entries);
672                 remove_proc_entry(hwif->name, proc_ide_root);
673                 hwif->proc = NULL;
674         }
675 }
676
677 static int proc_print_driver(struct device_driver *drv, void *data)
678 {
679         ide_driver_t *ide_drv = container_of(drv, ide_driver_t, gen_driver);
680         struct seq_file *s = data;
681
682         seq_printf(s, "%s version %s\n", drv->name, ide_drv->version);
683
684         return 0;
685 }
686
687 static int ide_drivers_show(struct seq_file *s, void *p)
688 {
689         int err;
690
691         err = bus_for_each_drv(&ide_bus_type, NULL, s, proc_print_driver);
692         if (err < 0)
693                 printk(KERN_WARNING "IDE: %s: bus_for_each_drv error: %d\n",
694                         __func__, err);
695         return 0;
696 }
697
698 static int ide_drivers_open(struct inode *inode, struct file *file)
699 {
700         return single_open(file, &ide_drivers_show, NULL);
701 }
702
703 static const struct file_operations ide_drivers_operations = {
704         .owner          = THIS_MODULE,
705         .open           = ide_drivers_open,
706         .read           = seq_read,
707         .llseek         = seq_lseek,
708         .release        = single_release,
709 };
710
711 void proc_ide_create(void)
712 {
713         proc_ide_root = proc_mkdir("ide", NULL);
714
715         if (!proc_ide_root)
716                 return;
717
718         proc_create("drivers", 0, proc_ide_root, &ide_drivers_operations);
719 }
720
721 void proc_ide_destroy(void)
722 {
723         remove_proc_entry("drivers", proc_ide_root);
724         remove_proc_entry("ide", NULL);
725 }