Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / scsi / sd.c
1 /*
2 * sd.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 *
5 * Linux scsi disk driver
6 * Initial versions: Drew Eckhardt
7 * Subsequent revisions: Eric Youngdale
8 * Modification history:
9 * - Drew Eckhardt <drew@colorado.edu> original
10 * - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
11 * outstanding request, and other enhancements.
12 * Support loadable low-level scsi drivers.
13 * - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
14 * eight major numbers.
15 * - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
16 * - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
17 * sd_init and cleanups.
18 * - Alex Davis <letmein@erols.com> Fix problem where partition info
19 * not being read in sd_open. Fix problem where removable media
20 * could be ejected after sd_open.
21 * - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
22 * - Badari Pulavarty <pbadari@us.ibm.com>, Matthew Wilcox
23 * <willy@debian.org>, Kurt Garloff <garloff@suse.de>:
24 * Support 32k/1M disks.
25 *
26 * Logging policy (needs CONFIG_SCSI_LOGGING defined):
27 * - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
28 * - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
29 * - entering sd_ioctl: SCSI_LOG_IOCTL level 1
30 * - entering other commands: SCSI_LOG_HLQUEUE level 3
31 * Note: when the logging level is set by the user, it must be greater
32 * than the level indicated above to trigger output.
33 */
34
35 #include <linux/config.h>
36 #include <linux/module.h>
37 #include <linux/fs.h>
38 #include <linux/kernel.h>
39 #include <linux/sched.h>
40 #include <linux/mm.h>
41 #include <linux/bio.h>
42 #include <linux/genhd.h>
43 #include <linux/hdreg.h>
44 #include <linux/errno.h>
45 #include <linux/idr.h>
46 #include <linux/interrupt.h>
47 #include <linux/init.h>
48 #include <linux/blkdev.h>
49 #include <linux/blkpg.h>
50 #include <linux/kref.h>
51 #include <linux/delay.h>
52 #include <asm/uaccess.h>
53
54 #include <scsi/scsi.h>
55 #include <scsi/scsi_cmnd.h>
56 #include <scsi/scsi_dbg.h>
57 #include <scsi/scsi_device.h>
58 #include <scsi/scsi_driver.h>
59 #include <scsi/scsi_eh.h>
60 #include <scsi/scsi_host.h>
61 #include <scsi/scsi_ioctl.h>
62 #include <scsi/scsicam.h>
63
64 #include "scsi_logging.h"
65
66 /*
67 * More than enough for everybody ;) The huge number of majors
68 * is a leftover from 16bit dev_t days, we don't really need that
69 * much numberspace.
70 */
71 #define SD_MAJORS 16
72
73 /*
74 * This is limited by the naming scheme enforced in sd_probe,
75 * add another character to it if you really need more disks.
76 */
77 #define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26)
78
79 /*
80 * Time out in seconds for disks and Magneto-opticals (which are slower).
81 */
82 #define SD_TIMEOUT (30 * HZ)
83 #define SD_MOD_TIMEOUT (75 * HZ)
84
85 /*
86 * Number of allowed retries
87 */
88 #define SD_MAX_RETRIES 5
89 #define SD_PASSTHROUGH_RETRIES 1
90
91 static void scsi_disk_release(struct kref *kref);
92
93 struct scsi_disk {
94 struct scsi_driver *driver; /* always &sd_template */
95 struct scsi_device *device;
96 struct kref kref;
97 struct gendisk *disk;
98 unsigned int openers; /* protected by BKL for now, yuck */
99 sector_t capacity; /* size in 512-byte sectors */
100 u32 index;
101 u8 media_present;
102 u8 write_prot;
103 unsigned WCE : 1; /* state of disk WCE bit */
104 unsigned RCD : 1; /* state of disk RCD bit, unused */
105 };
106
107 static DEFINE_IDR(sd_index_idr);
108 static DEFINE_SPINLOCK(sd_index_lock);
109
110 /* This semaphore is used to mediate the 0->1 reference get in the
111 * face of object destruction (i.e. we can't allow a get on an
112 * object after last put) */
113 static DECLARE_MUTEX(sd_ref_sem);
114
115 static int sd_revalidate_disk(struct gendisk *disk);
116 static void sd_rw_intr(struct scsi_cmnd * SCpnt);
117
118 static int sd_probe(struct device *);
119 static int sd_remove(struct device *);
120 static void sd_shutdown(struct device *dev);
121 static void sd_rescan(struct device *);
122 static int sd_init_command(struct scsi_cmnd *);
123 static int sd_issue_flush(struct device *, sector_t *);
124 static void sd_end_flush(request_queue_t *, struct request *);
125 static int sd_prepare_flush(request_queue_t *, struct request *);
126 static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
127 unsigned char *buffer);
128
129 static struct scsi_driver sd_template = {
130 .owner = THIS_MODULE,
131 .gendrv = {
132 .name = "sd",
133 .probe = sd_probe,
134 .remove = sd_remove,
135 .shutdown = sd_shutdown,
136 },
137 .rescan = sd_rescan,
138 .init_command = sd_init_command,
139 .issue_flush = sd_issue_flush,
140 .prepare_flush = sd_prepare_flush,
141 .end_flush = sd_end_flush,
142 };
143
144 /*
145 * Device no to disk mapping:
146 *
147 * major disc2 disc p1
148 * |............|.............|....|....| <- dev_t
149 * 31 20 19 8 7 4 3 0
150 *
151 * Inside a major, we have 16k disks, however mapped non-
152 * contiguously. The first 16 disks are for major0, the next
153 * ones with major1, ... Disk 256 is for major0 again, disk 272
154 * for major1, ...
155 * As we stay compatible with our numbering scheme, we can reuse
156 * the well-know SCSI majors 8, 65--71, 136--143.
157 */
158 static int sd_major(int major_idx)
159 {
160 switch (major_idx) {
161 case 0:
162 return SCSI_DISK0_MAJOR;
163 case 1 ... 7:
164 return SCSI_DISK1_MAJOR + major_idx - 1;
165 case 8 ... 15:
166 return SCSI_DISK8_MAJOR + major_idx - 8;
167 default:
168 BUG();
169 return 0; /* shut up gcc */
170 }
171 }
172
173 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,kref)
174
175 static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
176 {
177 return container_of(disk->private_data, struct scsi_disk, driver);
178 }
179
180 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
181 {
182 struct scsi_disk *sdkp = NULL;
183
184 if (disk->private_data) {
185 sdkp = scsi_disk(disk);
186 if (scsi_device_get(sdkp->device) == 0)
187 kref_get(&sdkp->kref);
188 else
189 sdkp = NULL;
190 }
191 return sdkp;
192 }
193
194 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
195 {
196 struct scsi_disk *sdkp;
197
198 down(&sd_ref_sem);
199 sdkp = __scsi_disk_get(disk);
200 up(&sd_ref_sem);
201 return sdkp;
202 }
203
204 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
205 {
206 struct scsi_disk *sdkp;
207
208 down(&sd_ref_sem);
209 sdkp = dev_get_drvdata(dev);
210 if (sdkp)
211 sdkp = __scsi_disk_get(sdkp->disk);
212 up(&sd_ref_sem);
213 return sdkp;
214 }
215
216 static void scsi_disk_put(struct scsi_disk *sdkp)
217 {
218 struct scsi_device *sdev = sdkp->device;
219
220 down(&sd_ref_sem);
221 kref_put(&sdkp->kref, scsi_disk_release);
222 scsi_device_put(sdev);
223 up(&sd_ref_sem);
224 }
225
226 /**
227 * sd_init_command - build a scsi (read or write) command from
228 * information in the request structure.
229 * @SCpnt: pointer to mid-level's per scsi command structure that
230 * contains request and into which the scsi command is written
231 *
232 * Returns 1 if successful and 0 if error (or cannot be done now).
233 **/
234 static int sd_init_command(struct scsi_cmnd * SCpnt)
235 {
236 unsigned int this_count, timeout;
237 struct gendisk *disk;
238 sector_t block;
239 struct scsi_device *sdp = SCpnt->device;
240 struct request *rq = SCpnt->request;
241
242 timeout = sdp->timeout;
243
244 /*
245 * SG_IO from block layer already setup, just copy cdb basically
246 */
247 if (blk_pc_request(rq)) {
248 scsi_setup_blk_pc_cmnd(SCpnt);
249 if (rq->timeout)
250 timeout = rq->timeout;
251
252 goto queue;
253 }
254
255 /*
256 * we only do REQ_CMD and REQ_BLOCK_PC
257 */
258 if (!blk_fs_request(rq))
259 return 0;
260
261 disk = rq->rq_disk;
262 block = rq->sector;
263 this_count = SCpnt->request_bufflen >> 9;
264
265 SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
266 "count=%d\n", disk->disk_name,
267 (unsigned long long)block, this_count));
268
269 if (!sdp || !scsi_device_online(sdp) ||
270 block + rq->nr_sectors > get_capacity(disk)) {
271 SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
272 rq->nr_sectors));
273 SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
274 return 0;
275 }
276
277 if (sdp->changed) {
278 /*
279 * quietly refuse to do anything to a changed disc until
280 * the changed bit has been reset
281 */
282 /* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
283 return 0;
284 }
285 SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n",
286 disk->disk_name, (unsigned long long)block));
287
288 /*
289 * If we have a 1K hardware sectorsize, prevent access to single
290 * 512 byte sectors. In theory we could handle this - in fact
291 * the scsi cdrom driver must be able to handle this because
292 * we typically use 1K blocksizes, and cdroms typically have
293 * 2K hardware sectorsizes. Of course, things are simpler
294 * with the cdrom, since it is read-only. For performance
295 * reasons, the filesystems should be able to handle this
296 * and not force the scsi disk driver to use bounce buffers
297 * for this.
298 */
299 if (sdp->sector_size == 1024) {
300 if ((block & 1) || (rq->nr_sectors & 1)) {
301 printk(KERN_ERR "sd: Bad block number requested");
302 return 0;
303 } else {
304 block = block >> 1;
305 this_count = this_count >> 1;
306 }
307 }
308 if (sdp->sector_size == 2048) {
309 if ((block & 3) || (rq->nr_sectors & 3)) {
310 printk(KERN_ERR "sd: Bad block number requested");
311 return 0;
312 } else {
313 block = block >> 2;
314 this_count = this_count >> 2;
315 }
316 }
317 if (sdp->sector_size == 4096) {
318 if ((block & 7) || (rq->nr_sectors & 7)) {
319 printk(KERN_ERR "sd: Bad block number requested");
320 return 0;
321 } else {
322 block = block >> 3;
323 this_count = this_count >> 3;
324 }
325 }
326 if (rq_data_dir(rq) == WRITE) {
327 if (!sdp->writeable) {
328 return 0;
329 }
330 SCpnt->cmnd[0] = WRITE_6;
331 SCpnt->sc_data_direction = DMA_TO_DEVICE;
332 } else if (rq_data_dir(rq) == READ) {
333 SCpnt->cmnd[0] = READ_6;
334 SCpnt->sc_data_direction = DMA_FROM_DEVICE;
335 } else {
336 printk(KERN_ERR "sd: Unknown command %lx\n", rq->flags);
337 /* overkill panic("Unknown sd command %lx\n", rq->flags); */
338 return 0;
339 }
340
341 SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
342 disk->disk_name, (rq_data_dir(rq) == WRITE) ?
343 "writing" : "reading", this_count, rq->nr_sectors));
344
345 SCpnt->cmnd[1] = 0;
346
347 if (block > 0xffffffff) {
348 SCpnt->cmnd[0] += READ_16 - READ_6;
349 SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
350 SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
351 SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
352 SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
353 SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
354 SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
355 SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
356 SCpnt->cmnd[9] = (unsigned char) block & 0xff;
357 SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
358 SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
359 SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
360 SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
361 SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
362 } else if ((this_count > 0xff) || (block > 0x1fffff) ||
363 SCpnt->device->use_10_for_rw) {
364 if (this_count > 0xffff)
365 this_count = 0xffff;
366
367 SCpnt->cmnd[0] += READ_10 - READ_6;
368 SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
369 SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
370 SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
371 SCpnt->cmnd[5] = (unsigned char) block & 0xff;
372 SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
373 SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
374 SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
375 } else {
376 SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
377 SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
378 SCpnt->cmnd[3] = (unsigned char) block & 0xff;
379 SCpnt->cmnd[4] = (unsigned char) this_count;
380 SCpnt->cmnd[5] = 0;
381 }
382 SCpnt->request_bufflen = SCpnt->bufflen =
383 this_count * sdp->sector_size;
384
385 /*
386 * We shouldn't disconnect in the middle of a sector, so with a dumb
387 * host adapter, it's safe to assume that we can at least transfer
388 * this many bytes between each connect / disconnect.
389 */
390 SCpnt->transfersize = sdp->sector_size;
391 SCpnt->underflow = this_count << 9;
392 SCpnt->allowed = SD_MAX_RETRIES;
393
394 queue:
395 SCpnt->timeout_per_command = timeout;
396
397 /*
398 * This is the completion routine we use. This is matched in terms
399 * of capability to this function.
400 */
401 SCpnt->done = sd_rw_intr;
402
403 /*
404 * This indicates that the command is ready from our end to be
405 * queued.
406 */
407 return 1;
408 }
409
410 /**
411 * sd_open - open a scsi disk device
412 * @inode: only i_rdev member may be used
413 * @filp: only f_mode and f_flags may be used
414 *
415 * Returns 0 if successful. Returns a negated errno value in case
416 * of error.
417 *
418 * Note: This can be called from a user context (e.g. fsck(1) )
419 * or from within the kernel (e.g. as a result of a mount(1) ).
420 * In the latter case @inode and @filp carry an abridged amount
421 * of information as noted above.
422 **/
423 static int sd_open(struct inode *inode, struct file *filp)
424 {
425 struct gendisk *disk = inode->i_bdev->bd_disk;
426 struct scsi_disk *sdkp;
427 struct scsi_device *sdev;
428 int retval;
429
430 if (!(sdkp = scsi_disk_get(disk)))
431 return -ENXIO;
432
433
434 SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name));
435
436 sdev = sdkp->device;
437
438 /*
439 * If the device is in error recovery, wait until it is done.
440 * If the device is offline, then disallow any access to it.
441 */
442 retval = -ENXIO;
443 if (!scsi_block_when_processing_errors(sdev))
444 goto error_out;
445
446 if (sdev->removable || sdkp->write_prot)
447 check_disk_change(inode->i_bdev);
448
449 /*
450 * If the drive is empty, just let the open fail.
451 */
452 retval = -ENOMEDIUM;
453 if (sdev->removable && !sdkp->media_present &&
454 !(filp->f_flags & O_NDELAY))
455 goto error_out;
456
457 /*
458 * If the device has the write protect tab set, have the open fail
459 * if the user expects to be able to write to the thing.
460 */
461 retval = -EROFS;
462 if (sdkp->write_prot && (filp->f_mode & FMODE_WRITE))
463 goto error_out;
464
465 /*
466 * It is possible that the disk changing stuff resulted in
467 * the device being taken offline. If this is the case,
468 * report this to the user, and don't pretend that the
469 * open actually succeeded.
470 */
471 retval = -ENXIO;
472 if (!scsi_device_online(sdev))
473 goto error_out;
474
475 if (!sdkp->openers++ && sdev->removable) {
476 if (scsi_block_when_processing_errors(sdev))
477 scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
478 }
479
480 return 0;
481
482 error_out:
483 scsi_disk_put(sdkp);
484 return retval;
485 }
486
487 /**
488 * sd_release - invoked when the (last) close(2) is called on this
489 * scsi disk.
490 * @inode: only i_rdev member may be used
491 * @filp: only f_mode and f_flags may be used
492 *
493 * Returns 0.
494 *
495 * Note: may block (uninterruptible) if error recovery is underway
496 * on this disk.
497 **/
498 static int sd_release(struct inode *inode, struct file *filp)
499 {
500 struct gendisk *disk = inode->i_bdev->bd_disk;
501 struct scsi_disk *sdkp = scsi_disk(disk);
502 struct scsi_device *sdev = sdkp->device;
503
504 SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name));
505
506 if (!--sdkp->openers && sdev->removable) {
507 if (scsi_block_when_processing_errors(sdev))
508 scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
509 }
510
511 /*
512 * XXX and what if there are packets in flight and this close()
513 * XXX is followed by a "rmmod sd_mod"?
514 */
515 scsi_disk_put(sdkp);
516 return 0;
517 }
518
519 static int sd_hdio_getgeo(struct block_device *bdev, struct hd_geometry __user *loc)
520 {
521 struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
522 struct scsi_device *sdp = sdkp->device;
523 struct Scsi_Host *host = sdp->host;
524 int diskinfo[4];
525
526 /* default to most commonly used values */
527 diskinfo[0] = 0x40; /* 1 << 6 */
528 diskinfo[1] = 0x20; /* 1 << 5 */
529 diskinfo[2] = sdkp->capacity >> 11;
530
531 /* override with calculated, extended default, or driver values */
532 if (host->hostt->bios_param)
533 host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
534 else
535 scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
536
537 if (put_user(diskinfo[0], &loc->heads))
538 return -EFAULT;
539 if (put_user(diskinfo[1], &loc->sectors))
540 return -EFAULT;
541 if (put_user(diskinfo[2], &loc->cylinders))
542 return -EFAULT;
543 if (put_user((unsigned)get_start_sect(bdev),
544 (unsigned long __user *)&loc->start))
545 return -EFAULT;
546 return 0;
547 }
548
549 /**
550 * sd_ioctl - process an ioctl
551 * @inode: only i_rdev/i_bdev members may be used
552 * @filp: only f_mode and f_flags may be used
553 * @cmd: ioctl command number
554 * @arg: this is third argument given to ioctl(2) system call.
555 * Often contains a pointer.
556 *
557 * Returns 0 if successful (some ioctls return postive numbers on
558 * success as well). Returns a negated errno value in case of error.
559 *
560 * Note: most ioctls are forward onto the block subsystem or further
561 * down in the scsi subsytem.
562 **/
563 static int sd_ioctl(struct inode * inode, struct file * filp,
564 unsigned int cmd, unsigned long arg)
565 {
566 struct block_device *bdev = inode->i_bdev;
567 struct gendisk *disk = bdev->bd_disk;
568 struct scsi_device *sdp = scsi_disk(disk)->device;
569 void __user *p = (void __user *)arg;
570 int error;
571
572 SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
573 disk->disk_name, cmd));
574
575 /*
576 * If we are in the middle of error recovery, don't let anyone
577 * else try and use this device. Also, if error recovery fails, it
578 * may try and take the device offline, in which case all further
579 * access to the device is prohibited.
580 */
581 error = scsi_nonblockable_ioctl(sdp, cmd, p, filp);
582 if (!scsi_block_when_processing_errors(sdp) || !error)
583 return error;
584
585 if (cmd == HDIO_GETGEO) {
586 if (!arg)
587 return -EINVAL;
588 return sd_hdio_getgeo(bdev, p);
589 }
590
591 /*
592 * Send SCSI addressing ioctls directly to mid level, send other
593 * ioctls to block level and then onto mid level if they can't be
594 * resolved.
595 */
596 switch (cmd) {
597 case SCSI_IOCTL_GET_IDLUN:
598 case SCSI_IOCTL_GET_BUS_NUMBER:
599 return scsi_ioctl(sdp, cmd, p);
600 default:
601 error = scsi_cmd_ioctl(filp, disk, cmd, p);
602 if (error != -ENOTTY)
603 return error;
604 }
605 return scsi_ioctl(sdp, cmd, p);
606 }
607
608 static void set_media_not_present(struct scsi_disk *sdkp)
609 {
610 sdkp->media_present = 0;
611 sdkp->capacity = 0;
612 sdkp->device->changed = 1;
613 }
614
615 /**
616 * sd_media_changed - check if our medium changed
617 * @disk: kernel device descriptor
618 *
619 * Returns 0 if not applicable or no change; 1 if change
620 *
621 * Note: this function is invoked from the block subsystem.
622 **/
623 static int sd_media_changed(struct gendisk *disk)
624 {
625 struct scsi_disk *sdkp = scsi_disk(disk);
626 struct scsi_device *sdp = sdkp->device;
627 int retval;
628
629 SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n",
630 disk->disk_name));
631
632 if (!sdp->removable)
633 return 0;
634
635 /*
636 * If the device is offline, don't send any commands - just pretend as
637 * if the command failed. If the device ever comes back online, we
638 * can deal with it then. It is only because of unrecoverable errors
639 * that we would ever take a device offline in the first place.
640 */
641 if (!scsi_device_online(sdp))
642 goto not_present;
643
644 /*
645 * Using TEST_UNIT_READY enables differentiation between drive with
646 * no cartridge loaded - NOT READY, drive with changed cartridge -
647 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
648 *
649 * Drives that auto spin down. eg iomega jaz 1G, will be started
650 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
651 * sd_revalidate() is called.
652 */
653 retval = -ENODEV;
654 if (scsi_block_when_processing_errors(sdp))
655 retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES);
656
657 /*
658 * Unable to test, unit probably not ready. This usually
659 * means there is no disc in the drive. Mark as changed,
660 * and we will figure it out later once the drive is
661 * available again.
662 */
663 if (retval)
664 goto not_present;
665
666 /*
667 * For removable scsi disk we have to recognise the presence
668 * of a disk in the drive. This is kept in the struct scsi_disk
669 * struct and tested at open ! Daniel Roche (dan@lectra.fr)
670 */
671 sdkp->media_present = 1;
672
673 retval = sdp->changed;
674 sdp->changed = 0;
675
676 return retval;
677
678 not_present:
679 set_media_not_present(sdkp);
680 return 1;
681 }
682
683 static int sd_sync_cache(struct scsi_device *sdp)
684 {
685 int retries, res;
686 struct scsi_sense_hdr sshdr;
687
688 if (!scsi_device_online(sdp))
689 return -ENODEV;
690
691
692 for (retries = 3; retries > 0; --retries) {
693 unsigned char cmd[10] = { 0 };
694
695 cmd[0] = SYNCHRONIZE_CACHE;
696 /*
697 * Leave the rest of the command zero to indicate
698 * flush everything.
699 */
700 res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
701 SD_TIMEOUT, SD_MAX_RETRIES);
702 if (res == 0)
703 break;
704 }
705
706 if (res) { printk(KERN_WARNING "FAILED\n status = %x, message = %02x, "
707 "host = %d, driver = %02x\n ",
708 status_byte(res), msg_byte(res),
709 host_byte(res), driver_byte(res));
710 if (driver_byte(res) & DRIVER_SENSE)
711 scsi_print_sense_hdr("sd", &sshdr);
712 }
713
714 return res;
715 }
716
717 static int sd_issue_flush(struct device *dev, sector_t *error_sector)
718 {
719 int ret = 0;
720 struct scsi_device *sdp = to_scsi_device(dev);
721 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
722
723 if (!sdkp)
724 return -ENODEV;
725
726 if (sdkp->WCE)
727 ret = sd_sync_cache(sdp);
728 scsi_disk_put(sdkp);
729 return ret;
730 }
731
732 static void sd_end_flush(request_queue_t *q, struct request *flush_rq)
733 {
734 struct request *rq = flush_rq->end_io_data;
735 struct scsi_cmnd *cmd = rq->special;
736 unsigned int bytes = rq->hard_nr_sectors << 9;
737
738 if (!flush_rq->errors) {
739 spin_unlock(q->queue_lock);
740 scsi_io_completion(cmd, bytes, 0);
741 spin_lock(q->queue_lock);
742 } else if (blk_barrier_postflush(rq)) {
743 spin_unlock(q->queue_lock);
744 scsi_io_completion(cmd, 0, bytes);
745 spin_lock(q->queue_lock);
746 } else {
747 /*
748 * force journal abort of barriers
749 */
750 end_that_request_first(rq, -EOPNOTSUPP, rq->hard_nr_sectors);
751 end_that_request_last(rq);
752 }
753 }
754
755 static int sd_prepare_flush(request_queue_t *q, struct request *rq)
756 {
757 struct scsi_device *sdev = q->queuedata;
758 struct scsi_disk *sdkp = dev_get_drvdata(&sdev->sdev_gendev);
759
760 if (!sdkp || !sdkp->WCE)
761 return 0;
762
763 memset(rq->cmd, 0, sizeof(rq->cmd));
764 rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER;
765 rq->timeout = SD_TIMEOUT;
766 rq->cmd[0] = SYNCHRONIZE_CACHE;
767 return 1;
768 }
769
770 static void sd_rescan(struct device *dev)
771 {
772 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
773
774 if (sdkp) {
775 sd_revalidate_disk(sdkp->disk);
776 scsi_disk_put(sdkp);
777 }
778 }
779
780
781 #ifdef CONFIG_COMPAT
782 /*
783 * This gets directly called from VFS. When the ioctl
784 * is not recognized we go back to the other translation paths.
785 */
786 static long sd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
787 {
788 struct block_device *bdev = file->f_dentry->d_inode->i_bdev;
789 struct gendisk *disk = bdev->bd_disk;
790 struct scsi_device *sdev = scsi_disk(disk)->device;
791
792 /*
793 * If we are in the middle of error recovery, don't let anyone
794 * else try and use this device. Also, if error recovery fails, it
795 * may try and take the device offline, in which case all further
796 * access to the device is prohibited.
797 */
798 if (!scsi_block_when_processing_errors(sdev))
799 return -ENODEV;
800
801 if (sdev->host->hostt->compat_ioctl) {
802 int ret;
803
804 ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
805
806 return ret;
807 }
808
809 /*
810 * Let the static ioctl translation table take care of it.
811 */
812 return -ENOIOCTLCMD;
813 }
814 #endif
815
816 static struct block_device_operations sd_fops = {
817 .owner = THIS_MODULE,
818 .open = sd_open,
819 .release = sd_release,
820 .ioctl = sd_ioctl,
821 #ifdef CONFIG_COMPAT
822 .compat_ioctl = sd_compat_ioctl,
823 #endif
824 .media_changed = sd_media_changed,
825 .revalidate_disk = sd_revalidate_disk,
826 };
827
828 /**
829 * sd_rw_intr - bottom half handler: called when the lower level
830 * driver has completed (successfully or otherwise) a scsi command.
831 * @SCpnt: mid-level's per command structure.
832 *
833 * Note: potentially run from within an ISR. Must not block.
834 **/
835 static void sd_rw_intr(struct scsi_cmnd * SCpnt)
836 {
837 int result = SCpnt->result;
838 int this_count = SCpnt->bufflen;
839 int good_bytes = (result == 0 ? this_count : 0);
840 sector_t block_sectors = 1;
841 u64 first_err_block;
842 sector_t error_sector;
843 struct scsi_sense_hdr sshdr;
844 int sense_valid = 0;
845 int sense_deferred = 0;
846 int info_valid;
847
848 if (result) {
849 sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
850 if (sense_valid)
851 sense_deferred = scsi_sense_is_deferred(&sshdr);
852 }
853
854 #ifdef CONFIG_SCSI_LOGGING
855 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n",
856 SCpnt->request->rq_disk->disk_name, result));
857 if (sense_valid) {
858 SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[respc,sk,asc,"
859 "ascq]=%x,%x,%x,%x\n", sshdr.response_code,
860 sshdr.sense_key, sshdr.asc, sshdr.ascq));
861 }
862 #endif
863 /*
864 Handle MEDIUM ERRORs that indicate partial success. Since this is a
865 relatively rare error condition, no care is taken to avoid
866 unnecessary additional work such as memcpy's that could be avoided.
867 */
868
869 /*
870 * If SG_IO from block layer then set good_bytes to stop retries;
871 * else if errors, check them, and if necessary prepare for
872 * (partial) retries.
873 */
874 if (blk_pc_request(SCpnt->request))
875 good_bytes = this_count;
876 else if (driver_byte(result) != 0 &&
877 sense_valid && !sense_deferred) {
878 switch (sshdr.sense_key) {
879 case MEDIUM_ERROR:
880 if (!blk_fs_request(SCpnt->request))
881 break;
882 info_valid = scsi_get_sense_info_fld(
883 SCpnt->sense_buffer, SCSI_SENSE_BUFFERSIZE,
884 &first_err_block);
885 /*
886 * May want to warn and skip if following cast results
887 * in actual truncation (if sector_t < 64 bits)
888 */
889 error_sector = (sector_t)first_err_block;
890 if (SCpnt->request->bio != NULL)
891 block_sectors = bio_sectors(SCpnt->request->bio);
892 switch (SCpnt->device->sector_size) {
893 case 1024:
894 error_sector <<= 1;
895 if (block_sectors < 2)
896 block_sectors = 2;
897 break;
898 case 2048:
899 error_sector <<= 2;
900 if (block_sectors < 4)
901 block_sectors = 4;
902 break;
903 case 4096:
904 error_sector <<=3;
905 if (block_sectors < 8)
906 block_sectors = 8;
907 break;
908 case 256:
909 error_sector >>= 1;
910 break;
911 default:
912 break;
913 }
914
915 error_sector &= ~(block_sectors - 1);
916 good_bytes = (error_sector - SCpnt->request->sector) << 9;
917 if (good_bytes < 0 || good_bytes >= this_count)
918 good_bytes = 0;
919 break;
920
921 case RECOVERED_ERROR: /* an error occurred, but it recovered */
922 case NO_SENSE: /* LLDD got sense data */
923 /*
924 * Inform the user, but make sure that it's not treated
925 * as a hard error.
926 */
927 scsi_print_sense("sd", SCpnt);
928 SCpnt->result = 0;
929 memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
930 good_bytes = this_count;
931 break;
932
933 case ILLEGAL_REQUEST:
934 if (SCpnt->device->use_10_for_rw &&
935 (SCpnt->cmnd[0] == READ_10 ||
936 SCpnt->cmnd[0] == WRITE_10))
937 SCpnt->device->use_10_for_rw = 0;
938 if (SCpnt->device->use_10_for_ms &&
939 (SCpnt->cmnd[0] == MODE_SENSE_10 ||
940 SCpnt->cmnd[0] == MODE_SELECT_10))
941 SCpnt->device->use_10_for_ms = 0;
942 break;
943
944 default:
945 break;
946 }
947 }
948 /*
949 * This calls the generic completion function, now that we know
950 * how many actual sectors finished, and how many sectors we need
951 * to say have failed.
952 */
953 scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
954 }
955
956 static int media_not_present(struct scsi_disk *sdkp,
957 struct scsi_sense_hdr *sshdr)
958 {
959
960 if (!scsi_sense_valid(sshdr))
961 return 0;
962 /* not invoked for commands that could return deferred errors */
963 if (sshdr->sense_key != NOT_READY &&
964 sshdr->sense_key != UNIT_ATTENTION)
965 return 0;
966 if (sshdr->asc != 0x3A) /* medium not present */
967 return 0;
968
969 set_media_not_present(sdkp);
970 return 1;
971 }
972
973 /*
974 * spinup disk - called only in sd_revalidate_disk()
975 */
976 static void
977 sd_spinup_disk(struct scsi_disk *sdkp, char *diskname)
978 {
979 unsigned char cmd[10];
980 unsigned long spintime_expire = 0;
981 int retries, spintime;
982 unsigned int the_result;
983 struct scsi_sense_hdr sshdr;
984 int sense_valid = 0;
985
986 spintime = 0;
987
988 /* Spin up drives, as required. Only do this at boot time */
989 /* Spinup needs to be done for module loads too. */
990 do {
991 retries = 0;
992
993 do {
994 cmd[0] = TEST_UNIT_READY;
995 memset((void *) &cmd[1], 0, 9);
996
997 the_result = scsi_execute_req(sdkp->device, cmd,
998 DMA_NONE, NULL, 0,
999 &sshdr, SD_TIMEOUT,
1000 SD_MAX_RETRIES);
1001
1002 if (the_result)
1003 sense_valid = scsi_sense_valid(&sshdr);
1004 retries++;
1005 } while (retries < 3 &&
1006 (!scsi_status_is_good(the_result) ||
1007 ((driver_byte(the_result) & DRIVER_SENSE) &&
1008 sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1009
1010 /*
1011 * If the drive has indicated to us that it doesn't have
1012 * any media in it, don't bother with any of the rest of
1013 * this crap.
1014 */
1015 if (media_not_present(sdkp, &sshdr))
1016 return;
1017
1018 if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1019 /* no sense, TUR either succeeded or failed
1020 * with a status error */
1021 if(!spintime && !scsi_status_is_good(the_result))
1022 printk(KERN_NOTICE "%s: Unit Not Ready, "
1023 "error = 0x%x\n", diskname, the_result);
1024 break;
1025 }
1026
1027 /*
1028 * The device does not want the automatic start to be issued.
1029 */
1030 if (sdkp->device->no_start_on_add) {
1031 break;
1032 }
1033
1034 /*
1035 * If manual intervention is required, or this is an
1036 * absent USB storage device, a spinup is meaningless.
1037 */
1038 if (sense_valid &&
1039 sshdr.sense_key == NOT_READY &&
1040 sshdr.asc == 4 && sshdr.ascq == 3) {
1041 break; /* manual intervention required */
1042
1043 /*
1044 * Issue command to spin up drive when not ready
1045 */
1046 } else if (sense_valid && sshdr.sense_key == NOT_READY) {
1047 if (!spintime) {
1048 printk(KERN_NOTICE "%s: Spinning up disk...",
1049 diskname);
1050 cmd[0] = START_STOP;
1051 cmd[1] = 1; /* Return immediately */
1052 memset((void *) &cmd[2], 0, 8);
1053 cmd[4] = 1; /* Start spin cycle */
1054 scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1055 NULL, 0, &sshdr,
1056 SD_TIMEOUT, SD_MAX_RETRIES);
1057 spintime_expire = jiffies + 100 * HZ;
1058 spintime = 1;
1059 }
1060 /* Wait 1 second for next try */
1061 msleep(1000);
1062 printk(".");
1063
1064 /*
1065 * Wait for USB flash devices with slow firmware.
1066 * Yes, this sense key/ASC combination shouldn't
1067 * occur here. It's characteristic of these devices.
1068 */
1069 } else if (sense_valid &&
1070 sshdr.sense_key == UNIT_ATTENTION &&
1071 sshdr.asc == 0x28) {
1072 if (!spintime) {
1073 spintime_expire = jiffies + 5 * HZ;
1074 spintime = 1;
1075 }
1076 /* Wait 1 second for next try */
1077 msleep(1000);
1078 } else {
1079 /* we don't understand the sense code, so it's
1080 * probably pointless to loop */
1081 if(!spintime) {
1082 printk(KERN_NOTICE "%s: Unit Not Ready, "
1083 "sense:\n", diskname);
1084 scsi_print_sense_hdr("", &sshdr);
1085 }
1086 break;
1087 }
1088
1089 } while (spintime && time_before_eq(jiffies, spintime_expire));
1090
1091 if (spintime) {
1092 if (scsi_status_is_good(the_result))
1093 printk("ready\n");
1094 else
1095 printk("not responding...\n");
1096 }
1097 }
1098
1099 /*
1100 * read disk capacity
1101 */
1102 static void
1103 sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
1104 unsigned char *buffer)
1105 {
1106 unsigned char cmd[16];
1107 int the_result, retries;
1108 int sector_size = 0;
1109 int longrc = 0;
1110 struct scsi_sense_hdr sshdr;
1111 int sense_valid = 0;
1112 struct scsi_device *sdp = sdkp->device;
1113
1114 repeat:
1115 retries = 3;
1116 do {
1117 if (longrc) {
1118 memset((void *) cmd, 0, 16);
1119 cmd[0] = SERVICE_ACTION_IN;
1120 cmd[1] = SAI_READ_CAPACITY_16;
1121 cmd[13] = 12;
1122 memset((void *) buffer, 0, 12);
1123 } else {
1124 cmd[0] = READ_CAPACITY;
1125 memset((void *) &cmd[1], 0, 9);
1126 memset((void *) buffer, 0, 8);
1127 }
1128
1129 the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1130 buffer, longrc ? 12 : 8, &sshdr,
1131 SD_TIMEOUT, SD_MAX_RETRIES);
1132
1133 if (media_not_present(sdkp, &sshdr))
1134 return;
1135
1136 if (the_result)
1137 sense_valid = scsi_sense_valid(&sshdr);
1138 retries--;
1139
1140 } while (the_result && retries);
1141
1142 if (the_result && !longrc) {
1143 printk(KERN_NOTICE "%s : READ CAPACITY failed.\n"
1144 "%s : status=%x, message=%02x, host=%d, driver=%02x \n",
1145 diskname, diskname,
1146 status_byte(the_result),
1147 msg_byte(the_result),
1148 host_byte(the_result),
1149 driver_byte(the_result));
1150
1151 if (driver_byte(the_result) & DRIVER_SENSE)
1152 scsi_print_sense_hdr("sd", &sshdr);
1153 else
1154 printk("%s : sense not available. \n", diskname);
1155
1156 /* Set dirty bit for removable devices if not ready -
1157 * sometimes drives will not report this properly. */
1158 if (sdp->removable &&
1159 sense_valid && sshdr.sense_key == NOT_READY)
1160 sdp->changed = 1;
1161
1162 /* Either no media are present but the drive didn't tell us,
1163 or they are present but the read capacity command fails */
1164 /* sdkp->media_present = 0; -- not always correct */
1165 sdkp->capacity = 0x200000; /* 1 GB - random */
1166
1167 return;
1168 } else if (the_result && longrc) {
1169 /* READ CAPACITY(16) has been failed */
1170 printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n"
1171 "%s : status=%x, message=%02x, host=%d, driver=%02x \n",
1172 diskname, diskname,
1173 status_byte(the_result),
1174 msg_byte(the_result),
1175 host_byte(the_result),
1176 driver_byte(the_result));
1177 printk(KERN_NOTICE "%s : use 0xffffffff as device size\n",
1178 diskname);
1179
1180 sdkp->capacity = 1 + (sector_t) 0xffffffff;
1181 goto got_data;
1182 }
1183
1184 if (!longrc) {
1185 sector_size = (buffer[4] << 24) |
1186 (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
1187 if (buffer[0] == 0xff && buffer[1] == 0xff &&
1188 buffer[2] == 0xff && buffer[3] == 0xff) {
1189 if(sizeof(sdkp->capacity) > 4) {
1190 printk(KERN_NOTICE "%s : very big device. try to use"
1191 " READ CAPACITY(16).\n", diskname);
1192 longrc = 1;
1193 goto repeat;
1194 }
1195 printk(KERN_ERR "%s: too big for this kernel. Use a "
1196 "kernel compiled with support for large block "
1197 "devices.\n", diskname);
1198 sdkp->capacity = 0;
1199 goto got_data;
1200 }
1201 sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
1202 (buffer[1] << 16) |
1203 (buffer[2] << 8) |
1204 buffer[3]);
1205 } else {
1206 sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
1207 ((u64)buffer[1] << 48) |
1208 ((u64)buffer[2] << 40) |
1209 ((u64)buffer[3] << 32) |
1210 ((sector_t)buffer[4] << 24) |
1211 ((sector_t)buffer[5] << 16) |
1212 ((sector_t)buffer[6] << 8) |
1213 (sector_t)buffer[7]);
1214
1215 sector_size = (buffer[8] << 24) |
1216 (buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
1217 }
1218
1219 /* Some devices return the total number of sectors, not the
1220 * highest sector number. Make the necessary adjustment. */
1221 if (sdp->fix_capacity)
1222 --sdkp->capacity;
1223
1224 got_data:
1225 if (sector_size == 0) {
1226 sector_size = 512;
1227 printk(KERN_NOTICE "%s : sector size 0 reported, "
1228 "assuming 512.\n", diskname);
1229 }
1230
1231 if (sector_size != 512 &&
1232 sector_size != 1024 &&
1233 sector_size != 2048 &&
1234 sector_size != 4096 &&
1235 sector_size != 256) {
1236 printk(KERN_NOTICE "%s : unsupported sector size "
1237 "%d.\n", diskname, sector_size);
1238 /*
1239 * The user might want to re-format the drive with
1240 * a supported sectorsize. Once this happens, it
1241 * would be relatively trivial to set the thing up.
1242 * For this reason, we leave the thing in the table.
1243 */
1244 sdkp->capacity = 0;
1245 /*
1246 * set a bogus sector size so the normal read/write
1247 * logic in the block layer will eventually refuse any
1248 * request on this device without tripping over power
1249 * of two sector size assumptions
1250 */
1251 sector_size = 512;
1252 }
1253 {
1254 /*
1255 * The msdos fs needs to know the hardware sector size
1256 * So I have created this table. See ll_rw_blk.c
1257 * Jacques Gelinas (Jacques@solucorp.qc.ca)
1258 */
1259 int hard_sector = sector_size;
1260 sector_t sz = (sdkp->capacity/2) * (hard_sector/256);
1261 request_queue_t *queue = sdp->request_queue;
1262 sector_t mb = sz;
1263
1264 blk_queue_hardsect_size(queue, hard_sector);
1265 /* avoid 64-bit division on 32-bit platforms */
1266 sector_div(sz, 625);
1267 mb -= sz - 974;
1268 sector_div(mb, 1950);
1269
1270 printk(KERN_NOTICE "SCSI device %s: "
1271 "%llu %d-byte hdwr sectors (%llu MB)\n",
1272 diskname, (unsigned long long)sdkp->capacity,
1273 hard_sector, (unsigned long long)mb);
1274 }
1275
1276 /* Rescale capacity to 512-byte units */
1277 if (sector_size == 4096)
1278 sdkp->capacity <<= 3;
1279 else if (sector_size == 2048)
1280 sdkp->capacity <<= 2;
1281 else if (sector_size == 1024)
1282 sdkp->capacity <<= 1;
1283 else if (sector_size == 256)
1284 sdkp->capacity >>= 1;
1285
1286 sdkp->device->sector_size = sector_size;
1287 }
1288
1289 /* called with buffer of length 512 */
1290 static inline int
1291 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1292 unsigned char *buffer, int len, struct scsi_mode_data *data,
1293 struct scsi_sense_hdr *sshdr)
1294 {
1295 return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1296 SD_TIMEOUT, SD_MAX_RETRIES, data,
1297 sshdr);
1298 }
1299
1300 /*
1301 * read write protect setting, if possible - called only in sd_revalidate_disk()
1302 * called with buffer of length 512
1303 */
1304 static void
1305 sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname,
1306 unsigned char *buffer)
1307 {
1308 int res;
1309 struct scsi_device *sdp = sdkp->device;
1310 struct scsi_mode_data data;
1311
1312 set_disk_ro(sdkp->disk, 0);
1313 if (sdp->skip_ms_page_3f) {
1314 printk(KERN_NOTICE "%s: assuming Write Enabled\n", diskname);
1315 return;
1316 }
1317
1318 if (sdp->use_192_bytes_for_3f) {
1319 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1320 } else {
1321 /*
1322 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1323 * We have to start carefully: some devices hang if we ask
1324 * for more than is available.
1325 */
1326 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1327
1328 /*
1329 * Second attempt: ask for page 0 When only page 0 is
1330 * implemented, a request for page 3F may return Sense Key
1331 * 5: Illegal Request, Sense Code 24: Invalid field in
1332 * CDB.
1333 */
1334 if (!scsi_status_is_good(res))
1335 res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1336
1337 /*
1338 * Third attempt: ask 255 bytes, as we did earlier.
1339 */
1340 if (!scsi_status_is_good(res))
1341 res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1342 &data, NULL);
1343 }
1344
1345 if (!scsi_status_is_good(res)) {
1346 printk(KERN_WARNING
1347 "%s: test WP failed, assume Write Enabled\n", diskname);
1348 } else {
1349 sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1350 set_disk_ro(sdkp->disk, sdkp->write_prot);
1351 printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname,
1352 sdkp->write_prot ? "on" : "off");
1353 printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n",
1354 diskname, buffer[0], buffer[1], buffer[2], buffer[3]);
1355 }
1356 }
1357
1358 /*
1359 * sd_read_cache_type - called only from sd_revalidate_disk()
1360 * called with buffer of length 512
1361 */
1362 static void
1363 sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
1364 unsigned char *buffer)
1365 {
1366 int len = 0, res;
1367 struct scsi_device *sdp = sdkp->device;
1368
1369 int dbd;
1370 int modepage;
1371 struct scsi_mode_data data;
1372 struct scsi_sense_hdr sshdr;
1373
1374 if (sdp->skip_ms_page_8)
1375 goto defaults;
1376
1377 if (sdp->type == TYPE_RBC) {
1378 modepage = 6;
1379 dbd = 8;
1380 } else {
1381 modepage = 8;
1382 dbd = 0;
1383 }
1384
1385 /* cautiously ask */
1386 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1387
1388 if (!scsi_status_is_good(res))
1389 goto bad_sense;
1390
1391 /* that went OK, now ask for the proper length */
1392 len = data.length;
1393
1394 /*
1395 * We're only interested in the first three bytes, actually.
1396 * But the data cache page is defined for the first 20.
1397 */
1398 if (len < 3)
1399 goto bad_sense;
1400 if (len > 20)
1401 len = 20;
1402
1403 /* Take headers and block descriptors into account */
1404 len += data.header_length + data.block_descriptor_length;
1405
1406 /* Get the data */
1407 res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1408
1409 if (scsi_status_is_good(res)) {
1410 const char *types[] = {
1411 "write through", "none", "write back",
1412 "write back, no read (daft)"
1413 };
1414 int ct = 0;
1415 int offset = data.header_length + data.block_descriptor_length;
1416
1417 if ((buffer[offset] & 0x3f) != modepage) {
1418 printk(KERN_ERR "%s: got wrong page\n", diskname);
1419 goto defaults;
1420 }
1421
1422 if (modepage == 8) {
1423 sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1424 sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1425 } else {
1426 sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1427 sdkp->RCD = 0;
1428 }
1429
1430 ct = sdkp->RCD + 2*sdkp->WCE;
1431
1432 printk(KERN_NOTICE "SCSI device %s: drive cache: %s\n",
1433 diskname, types[ct]);
1434
1435 return;
1436 }
1437
1438 bad_sense:
1439 if (scsi_sense_valid(&sshdr) &&
1440 sshdr.sense_key == ILLEGAL_REQUEST &&
1441 sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1442 printk(KERN_NOTICE "%s: cache data unavailable\n",
1443 diskname); /* Invalid field in CDB */
1444 else
1445 printk(KERN_ERR "%s: asking for cache data failed\n",
1446 diskname);
1447
1448 defaults:
1449 printk(KERN_ERR "%s: assuming drive cache: write through\n",
1450 diskname);
1451 sdkp->WCE = 0;
1452 sdkp->RCD = 0;
1453 }
1454
1455 /**
1456 * sd_revalidate_disk - called the first time a new disk is seen,
1457 * performs disk spin up, read_capacity, etc.
1458 * @disk: struct gendisk we care about
1459 **/
1460 static int sd_revalidate_disk(struct gendisk *disk)
1461 {
1462 struct scsi_disk *sdkp = scsi_disk(disk);
1463 struct scsi_device *sdp = sdkp->device;
1464 unsigned char *buffer;
1465
1466 SCSI_LOG_HLQUEUE(3, printk("sd_revalidate_disk: disk=%s\n", disk->disk_name));
1467
1468 /*
1469 * If the device is offline, don't try and read capacity or any
1470 * of the other niceties.
1471 */
1472 if (!scsi_device_online(sdp))
1473 goto out;
1474
1475 buffer = kmalloc(512, GFP_KERNEL | __GFP_DMA);
1476 if (!buffer) {
1477 printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation "
1478 "failure.\n");
1479 goto out;
1480 }
1481
1482 /* defaults, until the device tells us otherwise */
1483 sdp->sector_size = 512;
1484 sdkp->capacity = 0;
1485 sdkp->media_present = 1;
1486 sdkp->write_prot = 0;
1487 sdkp->WCE = 0;
1488 sdkp->RCD = 0;
1489
1490 sd_spinup_disk(sdkp, disk->disk_name);
1491
1492 /*
1493 * Without media there is no reason to ask; moreover, some devices
1494 * react badly if we do.
1495 */
1496 if (sdkp->media_present) {
1497 sd_read_capacity(sdkp, disk->disk_name, buffer);
1498 sd_read_write_protect_flag(sdkp, disk->disk_name, buffer);
1499 sd_read_cache_type(sdkp, disk->disk_name, buffer);
1500 }
1501
1502 set_capacity(disk, sdkp->capacity);
1503 kfree(buffer);
1504
1505 out:
1506 return 0;
1507 }
1508
1509 /**
1510 * sd_probe - called during driver initialization and whenever a
1511 * new scsi device is attached to the system. It is called once
1512 * for each scsi device (not just disks) present.
1513 * @dev: pointer to device object
1514 *
1515 * Returns 0 if successful (or not interested in this scsi device
1516 * (e.g. scanner)); 1 when there is an error.
1517 *
1518 * Note: this function is invoked from the scsi mid-level.
1519 * This function sets up the mapping between a given
1520 * <host,channel,id,lun> (found in sdp) and new device name
1521 * (e.g. /dev/sda). More precisely it is the block device major
1522 * and minor number that is chosen here.
1523 *
1524 * Assume sd_attach is not re-entrant (for time being)
1525 * Also think about sd_attach() and sd_remove() running coincidentally.
1526 **/
1527 static int sd_probe(struct device *dev)
1528 {
1529 struct scsi_device *sdp = to_scsi_device(dev);
1530 struct scsi_disk *sdkp;
1531 struct gendisk *gd;
1532 u32 index;
1533 int error;
1534
1535 error = -ENODEV;
1536 if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
1537 goto out;
1538
1539 SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
1540 "sd_attach\n"));
1541
1542 error = -ENOMEM;
1543 sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL);
1544 if (!sdkp)
1545 goto out;
1546
1547 memset (sdkp, 0, sizeof(*sdkp));
1548 kref_init(&sdkp->kref);
1549
1550 gd = alloc_disk(16);
1551 if (!gd)
1552 goto out_free;
1553
1554 if (!idr_pre_get(&sd_index_idr, GFP_KERNEL))
1555 goto out_put;
1556
1557 spin_lock(&sd_index_lock);
1558 error = idr_get_new(&sd_index_idr, NULL, &index);
1559 spin_unlock(&sd_index_lock);
1560
1561 if (index >= SD_MAX_DISKS)
1562 error = -EBUSY;
1563 if (error)
1564 goto out_put;
1565
1566 get_device(&sdp->sdev_gendev);
1567 sdkp->device = sdp;
1568 sdkp->driver = &sd_template;
1569 sdkp->disk = gd;
1570 sdkp->index = index;
1571 sdkp->openers = 0;
1572
1573 if (!sdp->timeout) {
1574 if (sdp->type != TYPE_MOD)
1575 sdp->timeout = SD_TIMEOUT;
1576 else
1577 sdp->timeout = SD_MOD_TIMEOUT;
1578 }
1579
1580 gd->major = sd_major((index & 0xf0) >> 4);
1581 gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
1582 gd->minors = 16;
1583 gd->fops = &sd_fops;
1584
1585 if (index < 26) {
1586 sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
1587 } else if (index < (26 + 1) * 26) {
1588 sprintf(gd->disk_name, "sd%c%c",
1589 'a' + index / 26 - 1,'a' + index % 26);
1590 } else {
1591 const unsigned int m1 = (index / 26 - 1) / 26 - 1;
1592 const unsigned int m2 = (index / 26 - 1) % 26;
1593 const unsigned int m3 = index % 26;
1594 sprintf(gd->disk_name, "sd%c%c%c",
1595 'a' + m1, 'a' + m2, 'a' + m3);
1596 }
1597
1598 strcpy(gd->devfs_name, sdp->devfs_name);
1599
1600 gd->private_data = &sdkp->driver;
1601
1602 sd_revalidate_disk(gd);
1603
1604 gd->driverfs_dev = &sdp->sdev_gendev;
1605 gd->flags = GENHD_FL_DRIVERFS;
1606 if (sdp->removable)
1607 gd->flags |= GENHD_FL_REMOVABLE;
1608 gd->queue = sdkp->device->request_queue;
1609
1610 dev_set_drvdata(dev, sdkp);
1611 add_disk(gd);
1612
1613 sdev_printk(KERN_NOTICE, sdp, "Attached scsi %sdisk %s\n",
1614 sdp->removable ? "removable " : "", gd->disk_name);
1615
1616 return 0;
1617
1618 out_put:
1619 put_disk(gd);
1620 out_free:
1621 kfree(sdkp);
1622 out:
1623 return error;
1624 }
1625
1626 /**
1627 * sd_remove - called whenever a scsi disk (previously recognized by
1628 * sd_probe) is detached from the system. It is called (potentially
1629 * multiple times) during sd module unload.
1630 * @sdp: pointer to mid level scsi device object
1631 *
1632 * Note: this function is invoked from the scsi mid-level.
1633 * This function potentially frees up a device name (e.g. /dev/sdc)
1634 * that could be re-used by a subsequent sd_probe().
1635 * This function is not called when the built-in sd driver is "exit-ed".
1636 **/
1637 static int sd_remove(struct device *dev)
1638 {
1639 struct scsi_disk *sdkp = dev_get_drvdata(dev);
1640
1641 del_gendisk(sdkp->disk);
1642 sd_shutdown(dev);
1643
1644 down(&sd_ref_sem);
1645 dev_set_drvdata(dev, NULL);
1646 kref_put(&sdkp->kref, scsi_disk_release);
1647 up(&sd_ref_sem);
1648
1649 return 0;
1650 }
1651
1652 /**
1653 * scsi_disk_release - Called to free the scsi_disk structure
1654 * @kref: pointer to embedded kref
1655 *
1656 * sd_ref_sem must be held entering this routine. Because it is
1657 * called on last put, you should always use the scsi_disk_get()
1658 * scsi_disk_put() helpers which manipulate the semaphore directly
1659 * and never do a direct kref_put().
1660 **/
1661 static void scsi_disk_release(struct kref *kref)
1662 {
1663 struct scsi_disk *sdkp = to_scsi_disk(kref);
1664 struct gendisk *disk = sdkp->disk;
1665
1666 spin_lock(&sd_index_lock);
1667 idr_remove(&sd_index_idr, sdkp->index);
1668 spin_unlock(&sd_index_lock);
1669
1670 disk->private_data = NULL;
1671 put_disk(disk);
1672 put_device(&sdkp->device->sdev_gendev);
1673
1674 kfree(sdkp);
1675 }
1676
1677 /*
1678 * Send a SYNCHRONIZE CACHE instruction down to the device through
1679 * the normal SCSI command structure. Wait for the command to
1680 * complete.
1681 */
1682 static void sd_shutdown(struct device *dev)
1683 {
1684 struct scsi_device *sdp = to_scsi_device(dev);
1685 struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
1686
1687 if (!sdkp)
1688 return; /* this can happen */
1689
1690 if (sdkp->WCE) {
1691 printk(KERN_NOTICE "Synchronizing SCSI cache for disk %s: \n",
1692 sdkp->disk->disk_name);
1693 sd_sync_cache(sdp);
1694 }
1695 scsi_disk_put(sdkp);
1696 }
1697
1698 /**
1699 * init_sd - entry point for this driver (both when built in or when
1700 * a module).
1701 *
1702 * Note: this function registers this driver with the scsi mid-level.
1703 **/
1704 static int __init init_sd(void)
1705 {
1706 int majors = 0, i;
1707
1708 SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
1709
1710 for (i = 0; i < SD_MAJORS; i++)
1711 if (register_blkdev(sd_major(i), "sd") == 0)
1712 majors++;
1713
1714 if (!majors)
1715 return -ENODEV;
1716
1717 return scsi_register_driver(&sd_template.gendrv);
1718 }
1719
1720 /**
1721 * exit_sd - exit point for this driver (when it is a module).
1722 *
1723 * Note: this function unregisters this driver from the scsi mid-level.
1724 **/
1725 static void __exit exit_sd(void)
1726 {
1727 int i;
1728
1729 SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
1730
1731 scsi_unregister_driver(&sd_template.gendrv);
1732 for (i = 0; i < SD_MAJORS; i++)
1733 unregister_blkdev(sd_major(i), "sd");
1734 }
1735
1736 MODULE_LICENSE("GPL");
1737 MODULE_AUTHOR("Eric Youngdale");
1738 MODULE_DESCRIPTION("SCSI disk (sd) driver");
1739
1740 module_init(init_sd);
1741 module_exit(exit_sd);