xref: /openbmc/linux/drivers/scsi/sd.c (revision e8e0929d)
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/module.h>
36 #include <linux/fs.h>
37 #include <linux/kernel.h>
38 #include <linux/mm.h>
39 #include <linux/bio.h>
40 #include <linux/genhd.h>
41 #include <linux/hdreg.h>
42 #include <linux/errno.h>
43 #include <linux/idr.h>
44 #include <linux/interrupt.h>
45 #include <linux/init.h>
46 #include <linux/blkdev.h>
47 #include <linux/blkpg.h>
48 #include <linux/delay.h>
49 #include <linux/mutex.h>
50 #include <linux/string_helpers.h>
51 #include <linux/async.h>
52 #include <asm/uaccess.h>
53 #include <asm/unaligned.h>
54 
55 #include <scsi/scsi.h>
56 #include <scsi/scsi_cmnd.h>
57 #include <scsi/scsi_dbg.h>
58 #include <scsi/scsi_device.h>
59 #include <scsi/scsi_driver.h>
60 #include <scsi/scsi_eh.h>
61 #include <scsi/scsi_host.h>
62 #include <scsi/scsi_ioctl.h>
63 #include <scsi/scsicam.h>
64 
65 #include "sd.h"
66 #include "scsi_logging.h"
67 
68 MODULE_AUTHOR("Eric Youngdale");
69 MODULE_DESCRIPTION("SCSI disk (sd) driver");
70 MODULE_LICENSE("GPL");
71 
72 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK0_MAJOR);
73 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK1_MAJOR);
74 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK2_MAJOR);
75 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK3_MAJOR);
76 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK4_MAJOR);
77 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK5_MAJOR);
78 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK6_MAJOR);
79 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK7_MAJOR);
80 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK8_MAJOR);
81 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK9_MAJOR);
82 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK10_MAJOR);
83 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK11_MAJOR);
84 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK12_MAJOR);
85 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK13_MAJOR);
86 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK14_MAJOR);
87 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
88 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
89 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
90 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
91 
92 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
93 #define SD_MINORS	16
94 #else
95 #define SD_MINORS	0
96 #endif
97 
98 static int  sd_revalidate_disk(struct gendisk *);
99 static int  sd_probe(struct device *);
100 static int  sd_remove(struct device *);
101 static void sd_shutdown(struct device *);
102 static int sd_suspend(struct device *, pm_message_t state);
103 static int sd_resume(struct device *);
104 static void sd_rescan(struct device *);
105 static int sd_done(struct scsi_cmnd *);
106 static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
107 static void scsi_disk_release(struct device *cdev);
108 static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *);
109 static void sd_print_result(struct scsi_disk *, int);
110 
111 static DEFINE_SPINLOCK(sd_index_lock);
112 static DEFINE_IDA(sd_index_ida);
113 
114 /* This semaphore is used to mediate the 0->1 reference get in the
115  * face of object destruction (i.e. we can't allow a get on an
116  * object after last put) */
117 static DEFINE_MUTEX(sd_ref_mutex);
118 
119 static const char *sd_cache_types[] = {
120 	"write through", "none", "write back",
121 	"write back, no read (daft)"
122 };
123 
124 static ssize_t
125 sd_store_cache_type(struct device *dev, struct device_attribute *attr,
126 		    const char *buf, size_t count)
127 {
128 	int i, ct = -1, rcd, wce, sp;
129 	struct scsi_disk *sdkp = to_scsi_disk(dev);
130 	struct scsi_device *sdp = sdkp->device;
131 	char buffer[64];
132 	char *buffer_data;
133 	struct scsi_mode_data data;
134 	struct scsi_sense_hdr sshdr;
135 	int len;
136 
137 	if (sdp->type != TYPE_DISK)
138 		/* no cache control on RBC devices; theoretically they
139 		 * can do it, but there's probably so many exceptions
140 		 * it's not worth the risk */
141 		return -EINVAL;
142 
143 	for (i = 0; i < ARRAY_SIZE(sd_cache_types); i++) {
144 		const int len = strlen(sd_cache_types[i]);
145 		if (strncmp(sd_cache_types[i], buf, len) == 0 &&
146 		    buf[len] == '\n') {
147 			ct = i;
148 			break;
149 		}
150 	}
151 	if (ct < 0)
152 		return -EINVAL;
153 	rcd = ct & 0x01 ? 1 : 0;
154 	wce = ct & 0x02 ? 1 : 0;
155 	if (scsi_mode_sense(sdp, 0x08, 8, buffer, sizeof(buffer), SD_TIMEOUT,
156 			    SD_MAX_RETRIES, &data, NULL))
157 		return -EINVAL;
158 	len = min_t(size_t, sizeof(buffer), data.length - data.header_length -
159 		  data.block_descriptor_length);
160 	buffer_data = buffer + data.header_length +
161 		data.block_descriptor_length;
162 	buffer_data[2] &= ~0x05;
163 	buffer_data[2] |= wce << 2 | rcd;
164 	sp = buffer_data[0] & 0x80 ? 1 : 0;
165 
166 	if (scsi_mode_select(sdp, 1, sp, 8, buffer_data, len, SD_TIMEOUT,
167 			     SD_MAX_RETRIES, &data, &sshdr)) {
168 		if (scsi_sense_valid(&sshdr))
169 			sd_print_sense_hdr(sdkp, &sshdr);
170 		return -EINVAL;
171 	}
172 	revalidate_disk(sdkp->disk);
173 	return count;
174 }
175 
176 static ssize_t
177 sd_store_manage_start_stop(struct device *dev, struct device_attribute *attr,
178 			   const char *buf, size_t count)
179 {
180 	struct scsi_disk *sdkp = to_scsi_disk(dev);
181 	struct scsi_device *sdp = sdkp->device;
182 
183 	if (!capable(CAP_SYS_ADMIN))
184 		return -EACCES;
185 
186 	sdp->manage_start_stop = simple_strtoul(buf, NULL, 10);
187 
188 	return count;
189 }
190 
191 static ssize_t
192 sd_store_allow_restart(struct device *dev, struct device_attribute *attr,
193 		       const char *buf, size_t count)
194 {
195 	struct scsi_disk *sdkp = to_scsi_disk(dev);
196 	struct scsi_device *sdp = sdkp->device;
197 
198 	if (!capable(CAP_SYS_ADMIN))
199 		return -EACCES;
200 
201 	if (sdp->type != TYPE_DISK)
202 		return -EINVAL;
203 
204 	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
205 
206 	return count;
207 }
208 
209 static ssize_t
210 sd_show_cache_type(struct device *dev, struct device_attribute *attr,
211 		   char *buf)
212 {
213 	struct scsi_disk *sdkp = to_scsi_disk(dev);
214 	int ct = sdkp->RCD + 2*sdkp->WCE;
215 
216 	return snprintf(buf, 40, "%s\n", sd_cache_types[ct]);
217 }
218 
219 static ssize_t
220 sd_show_fua(struct device *dev, struct device_attribute *attr, char *buf)
221 {
222 	struct scsi_disk *sdkp = to_scsi_disk(dev);
223 
224 	return snprintf(buf, 20, "%u\n", sdkp->DPOFUA);
225 }
226 
227 static ssize_t
228 sd_show_manage_start_stop(struct device *dev, struct device_attribute *attr,
229 			  char *buf)
230 {
231 	struct scsi_disk *sdkp = to_scsi_disk(dev);
232 	struct scsi_device *sdp = sdkp->device;
233 
234 	return snprintf(buf, 20, "%u\n", sdp->manage_start_stop);
235 }
236 
237 static ssize_t
238 sd_show_allow_restart(struct device *dev, struct device_attribute *attr,
239 		      char *buf)
240 {
241 	struct scsi_disk *sdkp = to_scsi_disk(dev);
242 
243 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
244 }
245 
246 static ssize_t
247 sd_show_protection_type(struct device *dev, struct device_attribute *attr,
248 			char *buf)
249 {
250 	struct scsi_disk *sdkp = to_scsi_disk(dev);
251 
252 	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
253 }
254 
255 static ssize_t
256 sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
257 		    char *buf)
258 {
259 	struct scsi_disk *sdkp = to_scsi_disk(dev);
260 
261 	return snprintf(buf, 20, "%u\n", sdkp->ATO);
262 }
263 
264 static struct device_attribute sd_disk_attrs[] = {
265 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
266 	       sd_store_cache_type),
267 	__ATTR(FUA, S_IRUGO, sd_show_fua, NULL),
268 	__ATTR(allow_restart, S_IRUGO|S_IWUSR, sd_show_allow_restart,
269 	       sd_store_allow_restart),
270 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
271 	       sd_store_manage_start_stop),
272 	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
273 	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
274 	__ATTR_NULL,
275 };
276 
277 static struct class sd_disk_class = {
278 	.name		= "scsi_disk",
279 	.owner		= THIS_MODULE,
280 	.dev_release	= scsi_disk_release,
281 	.dev_attrs	= sd_disk_attrs,
282 };
283 
284 static struct scsi_driver sd_template = {
285 	.owner			= THIS_MODULE,
286 	.gendrv = {
287 		.name		= "sd",
288 		.probe		= sd_probe,
289 		.remove		= sd_remove,
290 		.suspend	= sd_suspend,
291 		.resume		= sd_resume,
292 		.shutdown	= sd_shutdown,
293 	},
294 	.rescan			= sd_rescan,
295 	.done			= sd_done,
296 };
297 
298 /*
299  * Device no to disk mapping:
300  *
301  *       major         disc2     disc  p1
302  *   |............|.............|....|....| <- dev_t
303  *    31        20 19          8 7  4 3  0
304  *
305  * Inside a major, we have 16k disks, however mapped non-
306  * contiguously. The first 16 disks are for major0, the next
307  * ones with major1, ... Disk 256 is for major0 again, disk 272
308  * for major1, ...
309  * As we stay compatible with our numbering scheme, we can reuse
310  * the well-know SCSI majors 8, 65--71, 136--143.
311  */
312 static int sd_major(int major_idx)
313 {
314 	switch (major_idx) {
315 	case 0:
316 		return SCSI_DISK0_MAJOR;
317 	case 1 ... 7:
318 		return SCSI_DISK1_MAJOR + major_idx - 1;
319 	case 8 ... 15:
320 		return SCSI_DISK8_MAJOR + major_idx - 8;
321 	default:
322 		BUG();
323 		return 0;	/* shut up gcc */
324 	}
325 }
326 
327 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)
328 {
329 	struct scsi_disk *sdkp = NULL;
330 
331 	if (disk->private_data) {
332 		sdkp = scsi_disk(disk);
333 		if (scsi_device_get(sdkp->device) == 0)
334 			get_device(&sdkp->dev);
335 		else
336 			sdkp = NULL;
337 	}
338 	return sdkp;
339 }
340 
341 static struct scsi_disk *scsi_disk_get(struct gendisk *disk)
342 {
343 	struct scsi_disk *sdkp;
344 
345 	mutex_lock(&sd_ref_mutex);
346 	sdkp = __scsi_disk_get(disk);
347 	mutex_unlock(&sd_ref_mutex);
348 	return sdkp;
349 }
350 
351 static struct scsi_disk *scsi_disk_get_from_dev(struct device *dev)
352 {
353 	struct scsi_disk *sdkp;
354 
355 	mutex_lock(&sd_ref_mutex);
356 	sdkp = dev_get_drvdata(dev);
357 	if (sdkp)
358 		sdkp = __scsi_disk_get(sdkp->disk);
359 	mutex_unlock(&sd_ref_mutex);
360 	return sdkp;
361 }
362 
363 static void scsi_disk_put(struct scsi_disk *sdkp)
364 {
365 	struct scsi_device *sdev = sdkp->device;
366 
367 	mutex_lock(&sd_ref_mutex);
368 	put_device(&sdkp->dev);
369 	scsi_device_put(sdev);
370 	mutex_unlock(&sd_ref_mutex);
371 }
372 
373 /**
374  *	sd_init_command - build a scsi (read or write) command from
375  *	information in the request structure.
376  *	@SCpnt: pointer to mid-level's per scsi command structure that
377  *	contains request and into which the scsi command is written
378  *
379  *	Returns 1 if successful and 0 if error (or cannot be done now).
380  **/
381 static int sd_prep_fn(struct request_queue *q, struct request *rq)
382 {
383 	struct scsi_cmnd *SCpnt;
384 	struct scsi_device *sdp = q->queuedata;
385 	struct gendisk *disk = rq->rq_disk;
386 	struct scsi_disk *sdkp;
387 	sector_t block = blk_rq_pos(rq);
388 	sector_t threshold;
389 	unsigned int this_count = blk_rq_sectors(rq);
390 	int ret, host_dif;
391 
392 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
393 		ret = scsi_setup_blk_pc_cmnd(sdp, rq);
394 		goto out;
395 	} else if (rq->cmd_type != REQ_TYPE_FS) {
396 		ret = BLKPREP_KILL;
397 		goto out;
398 	}
399 	ret = scsi_setup_fs_cmnd(sdp, rq);
400 	if (ret != BLKPREP_OK)
401 		goto out;
402 	SCpnt = rq->special;
403 	sdkp = scsi_disk(disk);
404 
405 	/* from here on until we're complete, any goto out
406 	 * is used for a killable error condition */
407 	ret = BLKPREP_KILL;
408 
409 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
410 					"sd_init_command: block=%llu, "
411 					"count=%d\n",
412 					(unsigned long long)block,
413 					this_count));
414 
415 	if (!sdp || !scsi_device_online(sdp) ||
416 	    block + blk_rq_sectors(rq) > get_capacity(disk)) {
417 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
418 						"Finishing %u sectors\n",
419 						blk_rq_sectors(rq)));
420 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
421 						"Retry with 0x%p\n", SCpnt));
422 		goto out;
423 	}
424 
425 	if (sdp->changed) {
426 		/*
427 		 * quietly refuse to do anything to a changed disc until
428 		 * the changed bit has been reset
429 		 */
430 		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
431 		goto out;
432 	}
433 
434 	/*
435 	 * Some SD card readers can't handle multi-sector accesses which touch
436 	 * the last one or two hardware sectors.  Split accesses as needed.
437 	 */
438 	threshold = get_capacity(disk) - SD_LAST_BUGGY_SECTORS *
439 		(sdp->sector_size / 512);
440 
441 	if (unlikely(sdp->last_sector_bug && block + this_count > threshold)) {
442 		if (block < threshold) {
443 			/* Access up to the threshold but not beyond */
444 			this_count = threshold - block;
445 		} else {
446 			/* Access only a single hardware sector */
447 			this_count = sdp->sector_size / 512;
448 		}
449 	}
450 
451 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
452 					(unsigned long long)block));
453 
454 	/*
455 	 * If we have a 1K hardware sectorsize, prevent access to single
456 	 * 512 byte sectors.  In theory we could handle this - in fact
457 	 * the scsi cdrom driver must be able to handle this because
458 	 * we typically use 1K blocksizes, and cdroms typically have
459 	 * 2K hardware sectorsizes.  Of course, things are simpler
460 	 * with the cdrom, since it is read-only.  For performance
461 	 * reasons, the filesystems should be able to handle this
462 	 * and not force the scsi disk driver to use bounce buffers
463 	 * for this.
464 	 */
465 	if (sdp->sector_size == 1024) {
466 		if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
467 			scmd_printk(KERN_ERR, SCpnt,
468 				    "Bad block number requested\n");
469 			goto out;
470 		} else {
471 			block = block >> 1;
472 			this_count = this_count >> 1;
473 		}
474 	}
475 	if (sdp->sector_size == 2048) {
476 		if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
477 			scmd_printk(KERN_ERR, SCpnt,
478 				    "Bad block number requested\n");
479 			goto out;
480 		} else {
481 			block = block >> 2;
482 			this_count = this_count >> 2;
483 		}
484 	}
485 	if (sdp->sector_size == 4096) {
486 		if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
487 			scmd_printk(KERN_ERR, SCpnt,
488 				    "Bad block number requested\n");
489 			goto out;
490 		} else {
491 			block = block >> 3;
492 			this_count = this_count >> 3;
493 		}
494 	}
495 	if (rq_data_dir(rq) == WRITE) {
496 		if (!sdp->writeable) {
497 			goto out;
498 		}
499 		SCpnt->cmnd[0] = WRITE_6;
500 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
501 
502 		if (blk_integrity_rq(rq) &&
503 		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
504 			goto out;
505 
506 	} else if (rq_data_dir(rq) == READ) {
507 		SCpnt->cmnd[0] = READ_6;
508 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;
509 	} else {
510 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %x\n", rq->cmd_flags);
511 		goto out;
512 	}
513 
514 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
515 					"%s %d/%u 512 byte blocks.\n",
516 					(rq_data_dir(rq) == WRITE) ?
517 					"writing" : "reading", this_count,
518 					blk_rq_sectors(rq)));
519 
520 	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
521 	host_dif = scsi_host_dif_capable(sdp->host, sdkp->protection_type);
522 	if (host_dif)
523 		SCpnt->cmnd[1] = 1 << 5;
524 	else
525 		SCpnt->cmnd[1] = 0;
526 
527 	if (block > 0xffffffff) {
528 		SCpnt->cmnd[0] += READ_16 - READ_6;
529 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
530 		SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
531 		SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
532 		SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
533 		SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
534 		SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
535 		SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
536 		SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
537 		SCpnt->cmnd[9] = (unsigned char) block & 0xff;
538 		SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
539 		SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
540 		SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
541 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
542 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
543 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
544 		   scsi_device_protection(SCpnt->device) ||
545 		   SCpnt->device->use_10_for_rw) {
546 		if (this_count > 0xffff)
547 			this_count = 0xffff;
548 
549 		SCpnt->cmnd[0] += READ_10 - READ_6;
550 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
551 		SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
552 		SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
553 		SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
554 		SCpnt->cmnd[5] = (unsigned char) block & 0xff;
555 		SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
556 		SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
557 		SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
558 	} else {
559 		if (unlikely(blk_fua_rq(rq))) {
560 			/*
561 			 * This happens only if this drive failed
562 			 * 10byte rw command with ILLEGAL_REQUEST
563 			 * during operation and thus turned off
564 			 * use_10_for_rw.
565 			 */
566 			scmd_printk(KERN_ERR, SCpnt,
567 				    "FUA write on READ/WRITE(6) drive\n");
568 			goto out;
569 		}
570 
571 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
572 		SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
573 		SCpnt->cmnd[3] = (unsigned char) block & 0xff;
574 		SCpnt->cmnd[4] = (unsigned char) this_count;
575 		SCpnt->cmnd[5] = 0;
576 	}
577 	SCpnt->sdb.length = this_count * sdp->sector_size;
578 
579 	/* If DIF or DIX is enabled, tell HBA how to handle request */
580 	if (host_dif || scsi_prot_sg_count(SCpnt))
581 		sd_dif_op(SCpnt, host_dif, scsi_prot_sg_count(SCpnt),
582 			  sdkp->protection_type);
583 
584 	/*
585 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
586 	 * host adapter, it's safe to assume that we can at least transfer
587 	 * this many bytes between each connect / disconnect.
588 	 */
589 	SCpnt->transfersize = sdp->sector_size;
590 	SCpnt->underflow = this_count << 9;
591 	SCpnt->allowed = SD_MAX_RETRIES;
592 
593 	/*
594 	 * This indicates that the command is ready from our end to be
595 	 * queued.
596 	 */
597 	ret = BLKPREP_OK;
598  out:
599 	return scsi_prep_return(q, rq, ret);
600 }
601 
602 /**
603  *	sd_open - open a scsi disk device
604  *	@inode: only i_rdev member may be used
605  *	@filp: only f_mode and f_flags may be used
606  *
607  *	Returns 0 if successful. Returns a negated errno value in case
608  *	of error.
609  *
610  *	Note: This can be called from a user context (e.g. fsck(1) )
611  *	or from within the kernel (e.g. as a result of a mount(1) ).
612  *	In the latter case @inode and @filp carry an abridged amount
613  *	of information as noted above.
614  **/
615 static int sd_open(struct block_device *bdev, fmode_t mode)
616 {
617 	struct scsi_disk *sdkp = scsi_disk_get(bdev->bd_disk);
618 	struct scsi_device *sdev;
619 	int retval;
620 
621 	if (!sdkp)
622 		return -ENXIO;
623 
624 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_open\n"));
625 
626 	sdev = sdkp->device;
627 
628 	/*
629 	 * If the device is in error recovery, wait until it is done.
630 	 * If the device is offline, then disallow any access to it.
631 	 */
632 	retval = -ENXIO;
633 	if (!scsi_block_when_processing_errors(sdev))
634 		goto error_out;
635 
636 	if (sdev->removable || sdkp->write_prot)
637 		check_disk_change(bdev);
638 
639 	/*
640 	 * If the drive is empty, just let the open fail.
641 	 */
642 	retval = -ENOMEDIUM;
643 	if (sdev->removable && !sdkp->media_present && !(mode & FMODE_NDELAY))
644 		goto error_out;
645 
646 	/*
647 	 * If the device has the write protect tab set, have the open fail
648 	 * if the user expects to be able to write to the thing.
649 	 */
650 	retval = -EROFS;
651 	if (sdkp->write_prot && (mode & FMODE_WRITE))
652 		goto error_out;
653 
654 	/*
655 	 * It is possible that the disk changing stuff resulted in
656 	 * the device being taken offline.  If this is the case,
657 	 * report this to the user, and don't pretend that the
658 	 * open actually succeeded.
659 	 */
660 	retval = -ENXIO;
661 	if (!scsi_device_online(sdev))
662 		goto error_out;
663 
664 	if (!sdkp->openers++ && sdev->removable) {
665 		if (scsi_block_when_processing_errors(sdev))
666 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
667 	}
668 
669 	return 0;
670 
671 error_out:
672 	scsi_disk_put(sdkp);
673 	return retval;
674 }
675 
676 /**
677  *	sd_release - invoked when the (last) close(2) is called on this
678  *	scsi disk.
679  *	@inode: only i_rdev member may be used
680  *	@filp: only f_mode and f_flags may be used
681  *
682  *	Returns 0.
683  *
684  *	Note: may block (uninterruptible) if error recovery is underway
685  *	on this disk.
686  **/
687 static int sd_release(struct gendisk *disk, fmode_t mode)
688 {
689 	struct scsi_disk *sdkp = scsi_disk(disk);
690 	struct scsi_device *sdev = sdkp->device;
691 
692 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_release\n"));
693 
694 	if (!--sdkp->openers && sdev->removable) {
695 		if (scsi_block_when_processing_errors(sdev))
696 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
697 	}
698 
699 	/*
700 	 * XXX and what if there are packets in flight and this close()
701 	 * XXX is followed by a "rmmod sd_mod"?
702 	 */
703 	scsi_disk_put(sdkp);
704 	return 0;
705 }
706 
707 static int sd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
708 {
709 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
710 	struct scsi_device *sdp = sdkp->device;
711 	struct Scsi_Host *host = sdp->host;
712 	int diskinfo[4];
713 
714 	/* default to most commonly used values */
715         diskinfo[0] = 0x40;	/* 1 << 6 */
716        	diskinfo[1] = 0x20;	/* 1 << 5 */
717        	diskinfo[2] = sdkp->capacity >> 11;
718 
719 	/* override with calculated, extended default, or driver values */
720 	if (host->hostt->bios_param)
721 		host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
722 	else
723 		scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
724 
725 	geo->heads = diskinfo[0];
726 	geo->sectors = diskinfo[1];
727 	geo->cylinders = diskinfo[2];
728 	return 0;
729 }
730 
731 /**
732  *	sd_ioctl - process an ioctl
733  *	@inode: only i_rdev/i_bdev members may be used
734  *	@filp: only f_mode and f_flags may be used
735  *	@cmd: ioctl command number
736  *	@arg: this is third argument given to ioctl(2) system call.
737  *	Often contains a pointer.
738  *
739  *	Returns 0 if successful (some ioctls return postive numbers on
740  *	success as well). Returns a negated errno value in case of error.
741  *
742  *	Note: most ioctls are forward onto the block subsystem or further
743  *	down in the scsi subsystem.
744  **/
745 static int sd_ioctl(struct block_device *bdev, fmode_t mode,
746 		    unsigned int cmd, unsigned long arg)
747 {
748 	struct gendisk *disk = bdev->bd_disk;
749 	struct scsi_device *sdp = scsi_disk(disk)->device;
750 	void __user *p = (void __user *)arg;
751 	int error;
752 
753 	SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
754 						disk->disk_name, cmd));
755 
756 	/*
757 	 * If we are in the middle of error recovery, don't let anyone
758 	 * else try and use this device.  Also, if error recovery fails, it
759 	 * may try and take the device offline, in which case all further
760 	 * access to the device is prohibited.
761 	 */
762 	error = scsi_nonblockable_ioctl(sdp, cmd, p,
763 					(mode & FMODE_NDELAY) != 0);
764 	if (!scsi_block_when_processing_errors(sdp) || !error)
765 		return error;
766 
767 	/*
768 	 * Send SCSI addressing ioctls directly to mid level, send other
769 	 * ioctls to block level and then onto mid level if they can't be
770 	 * resolved.
771 	 */
772 	switch (cmd) {
773 		case SCSI_IOCTL_GET_IDLUN:
774 		case SCSI_IOCTL_GET_BUS_NUMBER:
775 			return scsi_ioctl(sdp, cmd, p);
776 		default:
777 			error = scsi_cmd_ioctl(disk->queue, disk, mode, cmd, p);
778 			if (error != -ENOTTY)
779 				return error;
780 	}
781 	return scsi_ioctl(sdp, cmd, p);
782 }
783 
784 static void set_media_not_present(struct scsi_disk *sdkp)
785 {
786 	sdkp->media_present = 0;
787 	sdkp->capacity = 0;
788 	sdkp->device->changed = 1;
789 }
790 
791 /**
792  *	sd_media_changed - check if our medium changed
793  *	@disk: kernel device descriptor
794  *
795  *	Returns 0 if not applicable or no change; 1 if change
796  *
797  *	Note: this function is invoked from the block subsystem.
798  **/
799 static int sd_media_changed(struct gendisk *disk)
800 {
801 	struct scsi_disk *sdkp = scsi_disk(disk);
802 	struct scsi_device *sdp = sdkp->device;
803 	struct scsi_sense_hdr *sshdr = NULL;
804 	int retval;
805 
806 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
807 
808 	if (!sdp->removable)
809 		return 0;
810 
811 	/*
812 	 * If the device is offline, don't send any commands - just pretend as
813 	 * if the command failed.  If the device ever comes back online, we
814 	 * can deal with it then.  It is only because of unrecoverable errors
815 	 * that we would ever take a device offline in the first place.
816 	 */
817 	if (!scsi_device_online(sdp)) {
818 		set_media_not_present(sdkp);
819 		retval = 1;
820 		goto out;
821 	}
822 
823 	/*
824 	 * Using TEST_UNIT_READY enables differentiation between drive with
825 	 * no cartridge loaded - NOT READY, drive with changed cartridge -
826 	 * UNIT ATTENTION, or with same cartridge - GOOD STATUS.
827 	 *
828 	 * Drives that auto spin down. eg iomega jaz 1G, will be started
829 	 * by sd_spinup_disk() from sd_revalidate_disk(), which happens whenever
830 	 * sd_revalidate() is called.
831 	 */
832 	retval = -ENODEV;
833 
834 	if (scsi_block_when_processing_errors(sdp)) {
835 		sshdr  = kzalloc(sizeof(*sshdr), GFP_KERNEL);
836 		retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
837 					      sshdr);
838 	}
839 
840 	/*
841 	 * Unable to test, unit probably not ready.   This usually
842 	 * means there is no disc in the drive.  Mark as changed,
843 	 * and we will figure it out later once the drive is
844 	 * available again.
845 	 */
846 	if (retval || (scsi_sense_valid(sshdr) &&
847 		       /* 0x3a is medium not present */
848 		       sshdr->asc == 0x3a)) {
849 		set_media_not_present(sdkp);
850 		retval = 1;
851 		goto out;
852 	}
853 
854 	/*
855 	 * For removable scsi disk we have to recognise the presence
856 	 * of a disk in the drive. This is kept in the struct scsi_disk
857 	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
858 	 */
859 	sdkp->media_present = 1;
860 
861 	retval = sdp->changed;
862 	sdp->changed = 0;
863 out:
864 	if (retval != sdkp->previous_state)
865 		sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
866 	sdkp->previous_state = retval;
867 	kfree(sshdr);
868 	return retval;
869 }
870 
871 static int sd_sync_cache(struct scsi_disk *sdkp)
872 {
873 	int retries, res;
874 	struct scsi_device *sdp = sdkp->device;
875 	struct scsi_sense_hdr sshdr;
876 
877 	if (!scsi_device_online(sdp))
878 		return -ENODEV;
879 
880 
881 	for (retries = 3; retries > 0; --retries) {
882 		unsigned char cmd[10] = { 0 };
883 
884 		cmd[0] = SYNCHRONIZE_CACHE;
885 		/*
886 		 * Leave the rest of the command zero to indicate
887 		 * flush everything.
888 		 */
889 		res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
890 				       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
891 		if (res == 0)
892 			break;
893 	}
894 
895 	if (res) {
896 		sd_print_result(sdkp, res);
897 		if (driver_byte(res) & DRIVER_SENSE)
898 			sd_print_sense_hdr(sdkp, &sshdr);
899 	}
900 
901 	if (res)
902 		return -EIO;
903 	return 0;
904 }
905 
906 static void sd_prepare_flush(struct request_queue *q, struct request *rq)
907 {
908 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
909 	rq->timeout = SD_TIMEOUT;
910 	rq->cmd[0] = SYNCHRONIZE_CACHE;
911 	rq->cmd_len = 10;
912 }
913 
914 static void sd_rescan(struct device *dev)
915 {
916 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
917 
918 	if (sdkp) {
919 		revalidate_disk(sdkp->disk);
920 		scsi_disk_put(sdkp);
921 	}
922 }
923 
924 
925 #ifdef CONFIG_COMPAT
926 /*
927  * This gets directly called from VFS. When the ioctl
928  * is not recognized we go back to the other translation paths.
929  */
930 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
931 			   unsigned int cmd, unsigned long arg)
932 {
933 	struct scsi_device *sdev = scsi_disk(bdev->bd_disk)->device;
934 
935 	/*
936 	 * If we are in the middle of error recovery, don't let anyone
937 	 * else try and use this device.  Also, if error recovery fails, it
938 	 * may try and take the device offline, in which case all further
939 	 * access to the device is prohibited.
940 	 */
941 	if (!scsi_block_when_processing_errors(sdev))
942 		return -ENODEV;
943 
944 	if (sdev->host->hostt->compat_ioctl) {
945 		int ret;
946 
947 		ret = sdev->host->hostt->compat_ioctl(sdev, cmd, (void __user *)arg);
948 
949 		return ret;
950 	}
951 
952 	/*
953 	 * Let the static ioctl translation table take care of it.
954 	 */
955 	return -ENOIOCTLCMD;
956 }
957 #endif
958 
959 static const struct block_device_operations sd_fops = {
960 	.owner			= THIS_MODULE,
961 	.open			= sd_open,
962 	.release		= sd_release,
963 	.locked_ioctl		= sd_ioctl,
964 	.getgeo			= sd_getgeo,
965 #ifdef CONFIG_COMPAT
966 	.compat_ioctl		= sd_compat_ioctl,
967 #endif
968 	.media_changed		= sd_media_changed,
969 	.revalidate_disk	= sd_revalidate_disk,
970 };
971 
972 static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
973 {
974 	u64 start_lba = blk_rq_pos(scmd->request);
975 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
976 	u64 bad_lba;
977 	int info_valid;
978 
979 	if (!blk_fs_request(scmd->request))
980 		return 0;
981 
982 	info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
983 					     SCSI_SENSE_BUFFERSIZE,
984 					     &bad_lba);
985 	if (!info_valid)
986 		return 0;
987 
988 	if (scsi_bufflen(scmd) <= scmd->device->sector_size)
989 		return 0;
990 
991 	if (scmd->device->sector_size < 512) {
992 		/* only legitimate sector_size here is 256 */
993 		start_lba <<= 1;
994 		end_lba <<= 1;
995 	} else {
996 		/* be careful ... don't want any overflows */
997 		u64 factor = scmd->device->sector_size / 512;
998 		do_div(start_lba, factor);
999 		do_div(end_lba, factor);
1000 	}
1001 
1002 	/* The bad lba was reported incorrectly, we have no idea where
1003 	 * the error is.
1004 	 */
1005 	if (bad_lba < start_lba  || bad_lba >= end_lba)
1006 		return 0;
1007 
1008 	/* This computation should always be done in terms of
1009 	 * the resolution of the device's medium.
1010 	 */
1011 	return (bad_lba - start_lba) * scmd->device->sector_size;
1012 }
1013 
1014 /**
1015  *	sd_done - bottom half handler: called when the lower level
1016  *	driver has completed (successfully or otherwise) a scsi command.
1017  *	@SCpnt: mid-level's per command structure.
1018  *
1019  *	Note: potentially run from within an ISR. Must not block.
1020  **/
1021 static int sd_done(struct scsi_cmnd *SCpnt)
1022 {
1023 	int result = SCpnt->result;
1024 	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
1025 	struct scsi_sense_hdr sshdr;
1026 	int sense_valid = 0;
1027 	int sense_deferred = 0;
1028 
1029 	if (result) {
1030 		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
1031 		if (sense_valid)
1032 			sense_deferred = scsi_sense_is_deferred(&sshdr);
1033 	}
1034 #ifdef CONFIG_SCSI_LOGGING
1035 	SCSI_LOG_HLCOMPLETE(1, scsi_print_result(SCpnt));
1036 	if (sense_valid) {
1037 		SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
1038 						   "sd_done: sb[respc,sk,asc,"
1039 						   "ascq]=%x,%x,%x,%x\n",
1040 						   sshdr.response_code,
1041 						   sshdr.sense_key, sshdr.asc,
1042 						   sshdr.ascq));
1043 	}
1044 #endif
1045 	if (driver_byte(result) != DRIVER_SENSE &&
1046 	    (!sense_valid || sense_deferred))
1047 		goto out;
1048 
1049 	switch (sshdr.sense_key) {
1050 	case HARDWARE_ERROR:
1051 	case MEDIUM_ERROR:
1052 		good_bytes = sd_completed_bytes(SCpnt);
1053 		break;
1054 	case RECOVERED_ERROR:
1055 		good_bytes = scsi_bufflen(SCpnt);
1056 		break;
1057 	case NO_SENSE:
1058 		/* This indicates a false check condition, so ignore it.  An
1059 		 * unknown amount of data was transferred so treat it as an
1060 		 * error.
1061 		 */
1062 		scsi_print_sense("sd", SCpnt);
1063 		SCpnt->result = 0;
1064 		memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1065 		break;
1066 	case ABORTED_COMMAND:
1067 		if (sshdr.asc == 0x10) { /* DIF: Disk detected corruption */
1068 			scsi_print_result(SCpnt);
1069 			scsi_print_sense("sd", SCpnt);
1070 			good_bytes = sd_completed_bytes(SCpnt);
1071 		}
1072 		break;
1073 	case ILLEGAL_REQUEST:
1074 		if (sshdr.asc == 0x10) { /* DIX: HBA detected corruption */
1075 			scsi_print_result(SCpnt);
1076 			scsi_print_sense("sd", SCpnt);
1077 			good_bytes = sd_completed_bytes(SCpnt);
1078 		}
1079 		break;
1080 	default:
1081 		break;
1082 	}
1083  out:
1084 	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
1085 		sd_dif_complete(SCpnt, good_bytes);
1086 
1087 	return good_bytes;
1088 }
1089 
1090 static int media_not_present(struct scsi_disk *sdkp,
1091 			     struct scsi_sense_hdr *sshdr)
1092 {
1093 
1094 	if (!scsi_sense_valid(sshdr))
1095 		return 0;
1096 	/* not invoked for commands that could return deferred errors */
1097 	if (sshdr->sense_key != NOT_READY &&
1098 	    sshdr->sense_key != UNIT_ATTENTION)
1099 		return 0;
1100 	if (sshdr->asc != 0x3A) /* medium not present */
1101 		return 0;
1102 
1103 	set_media_not_present(sdkp);
1104 	return 1;
1105 }
1106 
1107 /*
1108  * spinup disk - called only in sd_revalidate_disk()
1109  */
1110 static void
1111 sd_spinup_disk(struct scsi_disk *sdkp)
1112 {
1113 	unsigned char cmd[10];
1114 	unsigned long spintime_expire = 0;
1115 	int retries, spintime;
1116 	unsigned int the_result;
1117 	struct scsi_sense_hdr sshdr;
1118 	int sense_valid = 0;
1119 
1120 	spintime = 0;
1121 
1122 	/* Spin up drives, as required.  Only do this at boot time */
1123 	/* Spinup needs to be done for module loads too. */
1124 	do {
1125 		retries = 0;
1126 
1127 		do {
1128 			cmd[0] = TEST_UNIT_READY;
1129 			memset((void *) &cmd[1], 0, 9);
1130 
1131 			the_result = scsi_execute_req(sdkp->device, cmd,
1132 						      DMA_NONE, NULL, 0,
1133 						      &sshdr, SD_TIMEOUT,
1134 						      SD_MAX_RETRIES, NULL);
1135 
1136 			/*
1137 			 * If the drive has indicated to us that it
1138 			 * doesn't have any media in it, don't bother
1139 			 * with any more polling.
1140 			 */
1141 			if (media_not_present(sdkp, &sshdr))
1142 				return;
1143 
1144 			if (the_result)
1145 				sense_valid = scsi_sense_valid(&sshdr);
1146 			retries++;
1147 		} while (retries < 3 &&
1148 			 (!scsi_status_is_good(the_result) ||
1149 			  ((driver_byte(the_result) & DRIVER_SENSE) &&
1150 			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
1151 
1152 		if ((driver_byte(the_result) & DRIVER_SENSE) == 0) {
1153 			/* no sense, TUR either succeeded or failed
1154 			 * with a status error */
1155 			if(!spintime && !scsi_status_is_good(the_result)) {
1156 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1157 				sd_print_result(sdkp, the_result);
1158 			}
1159 			break;
1160 		}
1161 
1162 		/*
1163 		 * The device does not want the automatic start to be issued.
1164 		 */
1165 		if (sdkp->device->no_start_on_add)
1166 			break;
1167 
1168 		if (sense_valid && sshdr.sense_key == NOT_READY) {
1169 			if (sshdr.asc == 4 && sshdr.ascq == 3)
1170 				break;	/* manual intervention required */
1171 			if (sshdr.asc == 4 && sshdr.ascq == 0xb)
1172 				break;	/* standby */
1173 			if (sshdr.asc == 4 && sshdr.ascq == 0xc)
1174 				break;	/* unavailable */
1175 			/*
1176 			 * Issue command to spin up drive when not ready
1177 			 */
1178 			if (!spintime) {
1179 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
1180 				cmd[0] = START_STOP;
1181 				cmd[1] = 1;	/* Return immediately */
1182 				memset((void *) &cmd[2], 0, 8);
1183 				cmd[4] = 1;	/* Start spin cycle */
1184 				if (sdkp->device->start_stop_pwr_cond)
1185 					cmd[4] |= 1 << 4;
1186 				scsi_execute_req(sdkp->device, cmd, DMA_NONE,
1187 						 NULL, 0, &sshdr,
1188 						 SD_TIMEOUT, SD_MAX_RETRIES,
1189 						 NULL);
1190 				spintime_expire = jiffies + 100 * HZ;
1191 				spintime = 1;
1192 			}
1193 			/* Wait 1 second for next try */
1194 			msleep(1000);
1195 			printk(".");
1196 
1197 		/*
1198 		 * Wait for USB flash devices with slow firmware.
1199 		 * Yes, this sense key/ASC combination shouldn't
1200 		 * occur here.  It's characteristic of these devices.
1201 		 */
1202 		} else if (sense_valid &&
1203 				sshdr.sense_key == UNIT_ATTENTION &&
1204 				sshdr.asc == 0x28) {
1205 			if (!spintime) {
1206 				spintime_expire = jiffies + 5 * HZ;
1207 				spintime = 1;
1208 			}
1209 			/* Wait 1 second for next try */
1210 			msleep(1000);
1211 		} else {
1212 			/* we don't understand the sense code, so it's
1213 			 * probably pointless to loop */
1214 			if(!spintime) {
1215 				sd_printk(KERN_NOTICE, sdkp, "Unit Not Ready\n");
1216 				sd_print_sense_hdr(sdkp, &sshdr);
1217 			}
1218 			break;
1219 		}
1220 
1221 	} while (spintime && time_before_eq(jiffies, spintime_expire));
1222 
1223 	if (spintime) {
1224 		if (scsi_status_is_good(the_result))
1225 			printk("ready\n");
1226 		else
1227 			printk("not responding...\n");
1228 	}
1229 }
1230 
1231 
1232 /*
1233  * Determine whether disk supports Data Integrity Field.
1234  */
1235 void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
1236 {
1237 	struct scsi_device *sdp = sdkp->device;
1238 	u8 type;
1239 
1240 	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
1241 		type = 0;
1242 	else
1243 		type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
1244 
1245 	sdkp->protection_type = type;
1246 
1247 	switch (type) {
1248 	case SD_DIF_TYPE0_PROTECTION:
1249 	case SD_DIF_TYPE1_PROTECTION:
1250 	case SD_DIF_TYPE3_PROTECTION:
1251 		break;
1252 
1253 	case SD_DIF_TYPE2_PROTECTION:
1254 		sd_printk(KERN_ERR, sdkp, "formatted with DIF Type 2 "	\
1255 			  "protection which is currently unsupported. "	\
1256 			  "Disabling disk!\n");
1257 		goto disable;
1258 
1259 	default:
1260 		sd_printk(KERN_ERR, sdkp, "formatted with unknown "	\
1261 			  "protection type %d. Disabling disk!\n", type);
1262 		goto disable;
1263 	}
1264 
1265 	return;
1266 
1267 disable:
1268 	sdkp->capacity = 0;
1269 }
1270 
1271 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
1272 			struct scsi_sense_hdr *sshdr, int sense_valid,
1273 			int the_result)
1274 {
1275 	sd_print_result(sdkp, the_result);
1276 	if (driver_byte(the_result) & DRIVER_SENSE)
1277 		sd_print_sense_hdr(sdkp, sshdr);
1278 	else
1279 		sd_printk(KERN_NOTICE, sdkp, "Sense not available.\n");
1280 
1281 	/*
1282 	 * Set dirty bit for removable devices if not ready -
1283 	 * sometimes drives will not report this properly.
1284 	 */
1285 	if (sdp->removable &&
1286 	    sense_valid && sshdr->sense_key == NOT_READY)
1287 		sdp->changed = 1;
1288 
1289 	/*
1290 	 * We used to set media_present to 0 here to indicate no media
1291 	 * in the drive, but some drives fail read capacity even with
1292 	 * media present, so we can't do that.
1293 	 */
1294 	sdkp->capacity = 0; /* unknown mapped to zero - as usual */
1295 }
1296 
1297 #define RC16_LEN 32
1298 #if RC16_LEN > SD_BUF_SIZE
1299 #error RC16_LEN must not be more than SD_BUF_SIZE
1300 #endif
1301 
1302 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
1303 						unsigned char *buffer)
1304 {
1305 	unsigned char cmd[16];
1306 	struct scsi_sense_hdr sshdr;
1307 	int sense_valid = 0;
1308 	int the_result;
1309 	int retries = 3;
1310 	unsigned int alignment;
1311 	unsigned long long lba;
1312 	unsigned sector_size;
1313 
1314 	do {
1315 		memset(cmd, 0, 16);
1316 		cmd[0] = SERVICE_ACTION_IN;
1317 		cmd[1] = SAI_READ_CAPACITY_16;
1318 		cmd[13] = RC16_LEN;
1319 		memset(buffer, 0, RC16_LEN);
1320 
1321 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1322 					buffer, RC16_LEN, &sshdr,
1323 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1324 
1325 		if (media_not_present(sdkp, &sshdr))
1326 			return -ENODEV;
1327 
1328 		if (the_result) {
1329 			sense_valid = scsi_sense_valid(&sshdr);
1330 			if (sense_valid &&
1331 			    sshdr.sense_key == ILLEGAL_REQUEST &&
1332 			    (sshdr.asc == 0x20 || sshdr.asc == 0x24) &&
1333 			    sshdr.ascq == 0x00)
1334 				/* Invalid Command Operation Code or
1335 				 * Invalid Field in CDB, just retry
1336 				 * silently with RC10 */
1337 				return -EINVAL;
1338 		}
1339 		retries--;
1340 
1341 	} while (the_result && retries);
1342 
1343 	if (the_result) {
1344 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY(16) failed\n");
1345 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1346 		return -EINVAL;
1347 	}
1348 
1349 	sector_size = get_unaligned_be32(&buffer[8]);
1350 	lba = get_unaligned_be64(&buffer[0]);
1351 
1352 	sd_read_protection_type(sdkp, buffer);
1353 
1354 	if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) {
1355 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1356 			"kernel compiled with support for large block "
1357 			"devices.\n");
1358 		sdkp->capacity = 0;
1359 		return -EOVERFLOW;
1360 	}
1361 
1362 	/* Logical blocks per physical block exponent */
1363 	sdkp->hw_sector_size = (1 << (buffer[13] & 0xf)) * sector_size;
1364 
1365 	/* Lowest aligned logical block */
1366 	alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
1367 	blk_queue_alignment_offset(sdp->request_queue, alignment);
1368 	if (alignment && sdkp->first_scan)
1369 		sd_printk(KERN_NOTICE, sdkp,
1370 			  "physical block alignment offset: %u\n", alignment);
1371 
1372 	sdkp->capacity = lba + 1;
1373 	return sector_size;
1374 }
1375 
1376 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
1377 						unsigned char *buffer)
1378 {
1379 	unsigned char cmd[16];
1380 	struct scsi_sense_hdr sshdr;
1381 	int sense_valid = 0;
1382 	int the_result;
1383 	int retries = 3;
1384 	sector_t lba;
1385 	unsigned sector_size;
1386 
1387 	do {
1388 		cmd[0] = READ_CAPACITY;
1389 		memset(&cmd[1], 0, 9);
1390 		memset(buffer, 0, 8);
1391 
1392 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
1393 					buffer, 8, &sshdr,
1394 					SD_TIMEOUT, SD_MAX_RETRIES, NULL);
1395 
1396 		if (media_not_present(sdkp, &sshdr))
1397 			return -ENODEV;
1398 
1399 		if (the_result)
1400 			sense_valid = scsi_sense_valid(&sshdr);
1401 		retries--;
1402 
1403 	} while (the_result && retries);
1404 
1405 	if (the_result) {
1406 		sd_printk(KERN_NOTICE, sdkp, "READ CAPACITY failed\n");
1407 		read_capacity_error(sdkp, sdp, &sshdr, sense_valid, the_result);
1408 		return -EINVAL;
1409 	}
1410 
1411 	sector_size = get_unaligned_be32(&buffer[4]);
1412 	lba = get_unaligned_be32(&buffer[0]);
1413 
1414 	if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) {
1415 		sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
1416 			"kernel compiled with support for large block "
1417 			"devices.\n");
1418 		sdkp->capacity = 0;
1419 		return -EOVERFLOW;
1420 	}
1421 
1422 	sdkp->capacity = lba + 1;
1423 	sdkp->hw_sector_size = sector_size;
1424 	return sector_size;
1425 }
1426 
1427 static int sd_try_rc16_first(struct scsi_device *sdp)
1428 {
1429 	if (sdp->scsi_level > SCSI_SPC_2)
1430 		return 1;
1431 	if (scsi_device_protection(sdp))
1432 		return 1;
1433 	return 0;
1434 }
1435 
1436 /*
1437  * read disk capacity
1438  */
1439 static void
1440 sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
1441 {
1442 	int sector_size;
1443 	struct scsi_device *sdp = sdkp->device;
1444 	sector_t old_capacity = sdkp->capacity;
1445 
1446 	if (sd_try_rc16_first(sdp)) {
1447 		sector_size = read_capacity_16(sdkp, sdp, buffer);
1448 		if (sector_size == -EOVERFLOW)
1449 			goto got_data;
1450 		if (sector_size == -ENODEV)
1451 			return;
1452 		if (sector_size < 0)
1453 			sector_size = read_capacity_10(sdkp, sdp, buffer);
1454 		if (sector_size < 0)
1455 			return;
1456 	} else {
1457 		sector_size = read_capacity_10(sdkp, sdp, buffer);
1458 		if (sector_size == -EOVERFLOW)
1459 			goto got_data;
1460 		if (sector_size < 0)
1461 			return;
1462 		if ((sizeof(sdkp->capacity) > 4) &&
1463 		    (sdkp->capacity > 0xffffffffULL)) {
1464 			int old_sector_size = sector_size;
1465 			sd_printk(KERN_NOTICE, sdkp, "Very big device. "
1466 					"Trying to use READ CAPACITY(16).\n");
1467 			sector_size = read_capacity_16(sdkp, sdp, buffer);
1468 			if (sector_size < 0) {
1469 				sd_printk(KERN_NOTICE, sdkp,
1470 					"Using 0xffffffff as device size\n");
1471 				sdkp->capacity = 1 + (sector_t) 0xffffffff;
1472 				sector_size = old_sector_size;
1473 				goto got_data;
1474 			}
1475 		}
1476 	}
1477 
1478 	/* Some devices are known to return the total number of blocks,
1479 	 * not the highest block number.  Some devices have versions
1480 	 * which do this and others which do not.  Some devices we might
1481 	 * suspect of doing this but we don't know for certain.
1482 	 *
1483 	 * If we know the reported capacity is wrong, decrement it.  If
1484 	 * we can only guess, then assume the number of blocks is even
1485 	 * (usually true but not always) and err on the side of lowering
1486 	 * the capacity.
1487 	 */
1488 	if (sdp->fix_capacity ||
1489 	    (sdp->guess_capacity && (sdkp->capacity & 0x01))) {
1490 		sd_printk(KERN_INFO, sdkp, "Adjusting the sector count "
1491 				"from its reported value: %llu\n",
1492 				(unsigned long long) sdkp->capacity);
1493 		--sdkp->capacity;
1494 	}
1495 
1496 got_data:
1497 	if (sector_size == 0) {
1498 		sector_size = 512;
1499 		sd_printk(KERN_NOTICE, sdkp, "Sector size 0 reported, "
1500 			  "assuming 512.\n");
1501 	}
1502 
1503 	if (sector_size != 512 &&
1504 	    sector_size != 1024 &&
1505 	    sector_size != 2048 &&
1506 	    sector_size != 4096 &&
1507 	    sector_size != 256) {
1508 		sd_printk(KERN_NOTICE, sdkp, "Unsupported sector size %d.\n",
1509 			  sector_size);
1510 		/*
1511 		 * The user might want to re-format the drive with
1512 		 * a supported sectorsize.  Once this happens, it
1513 		 * would be relatively trivial to set the thing up.
1514 		 * For this reason, we leave the thing in the table.
1515 		 */
1516 		sdkp->capacity = 0;
1517 		/*
1518 		 * set a bogus sector size so the normal read/write
1519 		 * logic in the block layer will eventually refuse any
1520 		 * request on this device without tripping over power
1521 		 * of two sector size assumptions
1522 		 */
1523 		sector_size = 512;
1524 	}
1525 	blk_queue_logical_block_size(sdp->request_queue, sector_size);
1526 
1527 	{
1528 		char cap_str_2[10], cap_str_10[10];
1529 		u64 sz = (u64)sdkp->capacity << ilog2(sector_size);
1530 
1531 		string_get_size(sz, STRING_UNITS_2, cap_str_2,
1532 				sizeof(cap_str_2));
1533 		string_get_size(sz, STRING_UNITS_10, cap_str_10,
1534 				sizeof(cap_str_10));
1535 
1536 		if (sdkp->first_scan || old_capacity != sdkp->capacity) {
1537 			sd_printk(KERN_NOTICE, sdkp,
1538 				  "%llu %d-byte logical blocks: (%s/%s)\n",
1539 				  (unsigned long long)sdkp->capacity,
1540 				  sector_size, cap_str_10, cap_str_2);
1541 
1542 			if (sdkp->hw_sector_size != sector_size)
1543 				sd_printk(KERN_NOTICE, sdkp,
1544 					  "%u-byte physical blocks\n",
1545 					  sdkp->hw_sector_size);
1546 		}
1547 	}
1548 
1549 	/* Rescale capacity to 512-byte units */
1550 	if (sector_size == 4096)
1551 		sdkp->capacity <<= 3;
1552 	else if (sector_size == 2048)
1553 		sdkp->capacity <<= 2;
1554 	else if (sector_size == 1024)
1555 		sdkp->capacity <<= 1;
1556 	else if (sector_size == 256)
1557 		sdkp->capacity >>= 1;
1558 
1559 	blk_queue_physical_block_size(sdp->request_queue, sdkp->hw_sector_size);
1560 	sdkp->device->sector_size = sector_size;
1561 }
1562 
1563 /* called with buffer of length 512 */
1564 static inline int
1565 sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
1566 		 unsigned char *buffer, int len, struct scsi_mode_data *data,
1567 		 struct scsi_sense_hdr *sshdr)
1568 {
1569 	return scsi_mode_sense(sdp, dbd, modepage, buffer, len,
1570 			       SD_TIMEOUT, SD_MAX_RETRIES, data,
1571 			       sshdr);
1572 }
1573 
1574 /*
1575  * read write protect setting, if possible - called only in sd_revalidate_disk()
1576  * called with buffer of length SD_BUF_SIZE
1577  */
1578 static void
1579 sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
1580 {
1581 	int res;
1582 	struct scsi_device *sdp = sdkp->device;
1583 	struct scsi_mode_data data;
1584 	int old_wp = sdkp->write_prot;
1585 
1586 	set_disk_ro(sdkp->disk, 0);
1587 	if (sdp->skip_ms_page_3f) {
1588 		sd_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n");
1589 		return;
1590 	}
1591 
1592 	if (sdp->use_192_bytes_for_3f) {
1593 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 192, &data, NULL);
1594 	} else {
1595 		/*
1596 		 * First attempt: ask for all pages (0x3F), but only 4 bytes.
1597 		 * We have to start carefully: some devices hang if we ask
1598 		 * for more than is available.
1599 		 */
1600 		res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 4, &data, NULL);
1601 
1602 		/*
1603 		 * Second attempt: ask for page 0 When only page 0 is
1604 		 * implemented, a request for page 3F may return Sense Key
1605 		 * 5: Illegal Request, Sense Code 24: Invalid field in
1606 		 * CDB.
1607 		 */
1608 		if (!scsi_status_is_good(res))
1609 			res = sd_do_mode_sense(sdp, 0, 0, buffer, 4, &data, NULL);
1610 
1611 		/*
1612 		 * Third attempt: ask 255 bytes, as we did earlier.
1613 		 */
1614 		if (!scsi_status_is_good(res))
1615 			res = sd_do_mode_sense(sdp, 0, 0x3F, buffer, 255,
1616 					       &data, NULL);
1617 	}
1618 
1619 	if (!scsi_status_is_good(res)) {
1620 		sd_printk(KERN_WARNING, sdkp,
1621 			  "Test WP failed, assume Write Enabled\n");
1622 	} else {
1623 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
1624 		set_disk_ro(sdkp->disk, sdkp->write_prot);
1625 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
1626 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
1627 				  sdkp->write_prot ? "on" : "off");
1628 			sd_printk(KERN_DEBUG, sdkp,
1629 				  "Mode Sense: %02x %02x %02x %02x\n",
1630 				  buffer[0], buffer[1], buffer[2], buffer[3]);
1631 		}
1632 	}
1633 }
1634 
1635 /*
1636  * sd_read_cache_type - called only from sd_revalidate_disk()
1637  * called with buffer of length SD_BUF_SIZE
1638  */
1639 static void
1640 sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
1641 {
1642 	int len = 0, res;
1643 	struct scsi_device *sdp = sdkp->device;
1644 
1645 	int dbd;
1646 	int modepage;
1647 	struct scsi_mode_data data;
1648 	struct scsi_sense_hdr sshdr;
1649 	int old_wce = sdkp->WCE;
1650 	int old_rcd = sdkp->RCD;
1651 	int old_dpofua = sdkp->DPOFUA;
1652 
1653 	if (sdp->skip_ms_page_8)
1654 		goto defaults;
1655 
1656 	if (sdp->type == TYPE_RBC) {
1657 		modepage = 6;
1658 		dbd = 8;
1659 	} else {
1660 		modepage = 8;
1661 		dbd = 0;
1662 	}
1663 
1664 	/* cautiously ask */
1665 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, 4, &data, &sshdr);
1666 
1667 	if (!scsi_status_is_good(res))
1668 		goto bad_sense;
1669 
1670 	if (!data.header_length) {
1671 		modepage = 6;
1672 		sd_printk(KERN_ERR, sdkp, "Missing header in MODE_SENSE response\n");
1673 	}
1674 
1675 	/* that went OK, now ask for the proper length */
1676 	len = data.length;
1677 
1678 	/*
1679 	 * We're only interested in the first three bytes, actually.
1680 	 * But the data cache page is defined for the first 20.
1681 	 */
1682 	if (len < 3)
1683 		goto bad_sense;
1684 	if (len > 20)
1685 		len = 20;
1686 
1687 	/* Take headers and block descriptors into account */
1688 	len += data.header_length + data.block_descriptor_length;
1689 	if (len > SD_BUF_SIZE)
1690 		goto bad_sense;
1691 
1692 	/* Get the data */
1693 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
1694 
1695 	if (scsi_status_is_good(res)) {
1696 		int offset = data.header_length + data.block_descriptor_length;
1697 
1698 		if (offset >= SD_BUF_SIZE - 2) {
1699 			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
1700 			goto defaults;
1701 		}
1702 
1703 		if ((buffer[offset] & 0x3f) != modepage) {
1704 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
1705 			goto defaults;
1706 		}
1707 
1708 		if (modepage == 8) {
1709 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
1710 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
1711 		} else {
1712 			sdkp->WCE = ((buffer[offset + 2] & 0x01) == 0);
1713 			sdkp->RCD = 0;
1714 		}
1715 
1716 		sdkp->DPOFUA = (data.device_specific & 0x10) != 0;
1717 		if (sdkp->DPOFUA && !sdkp->device->use_10_for_rw) {
1718 			sd_printk(KERN_NOTICE, sdkp,
1719 				  "Uses READ/WRITE(6), disabling FUA\n");
1720 			sdkp->DPOFUA = 0;
1721 		}
1722 
1723 		if (sdkp->first_scan || old_wce != sdkp->WCE ||
1724 		    old_rcd != sdkp->RCD || old_dpofua != sdkp->DPOFUA)
1725 			sd_printk(KERN_NOTICE, sdkp,
1726 				  "Write cache: %s, read cache: %s, %s\n",
1727 				  sdkp->WCE ? "enabled" : "disabled",
1728 				  sdkp->RCD ? "disabled" : "enabled",
1729 				  sdkp->DPOFUA ? "supports DPO and FUA"
1730 				  : "doesn't support DPO or FUA");
1731 
1732 		return;
1733 	}
1734 
1735 bad_sense:
1736 	if (scsi_sense_valid(&sshdr) &&
1737 	    sshdr.sense_key == ILLEGAL_REQUEST &&
1738 	    sshdr.asc == 0x24 && sshdr.ascq == 0x0)
1739 		/* Invalid field in CDB */
1740 		sd_printk(KERN_NOTICE, sdkp, "Cache data unavailable\n");
1741 	else
1742 		sd_printk(KERN_ERR, sdkp, "Asking for cache data failed\n");
1743 
1744 defaults:
1745 	sd_printk(KERN_ERR, sdkp, "Assuming drive cache: write through\n");
1746 	sdkp->WCE = 0;
1747 	sdkp->RCD = 0;
1748 	sdkp->DPOFUA = 0;
1749 }
1750 
1751 /*
1752  * The ATO bit indicates whether the DIF application tag is available
1753  * for use by the operating system.
1754  */
1755 void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
1756 {
1757 	int res, offset;
1758 	struct scsi_device *sdp = sdkp->device;
1759 	struct scsi_mode_data data;
1760 	struct scsi_sense_hdr sshdr;
1761 
1762 	if (sdp->type != TYPE_DISK)
1763 		return;
1764 
1765 	if (sdkp->protection_type == 0)
1766 		return;
1767 
1768 	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
1769 			      SD_MAX_RETRIES, &data, &sshdr);
1770 
1771 	if (!scsi_status_is_good(res) || !data.header_length ||
1772 	    data.length < 6) {
1773 		sd_printk(KERN_WARNING, sdkp,
1774 			  "getting Control mode page failed, assume no ATO\n");
1775 
1776 		if (scsi_sense_valid(&sshdr))
1777 			sd_print_sense_hdr(sdkp, &sshdr);
1778 
1779 		return;
1780 	}
1781 
1782 	offset = data.header_length + data.block_descriptor_length;
1783 
1784 	if ((buffer[offset] & 0x3f) != 0x0a) {
1785 		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
1786 		return;
1787 	}
1788 
1789 	if ((buffer[offset + 5] & 0x80) == 0)
1790 		return;
1791 
1792 	sdkp->ATO = 1;
1793 
1794 	return;
1795 }
1796 
1797 /**
1798  * sd_read_block_limits - Query disk device for preferred I/O sizes.
1799  * @disk: disk to query
1800  */
1801 static void sd_read_block_limits(struct scsi_disk *sdkp)
1802 {
1803 	unsigned int sector_sz = sdkp->device->sector_size;
1804 	char *buffer;
1805 
1806 	/* Block Limits VPD */
1807 	buffer = scsi_get_vpd_page(sdkp->device, 0xb0);
1808 
1809 	if (buffer == NULL)
1810 		return;
1811 
1812 	blk_queue_io_min(sdkp->disk->queue,
1813 			 get_unaligned_be16(&buffer[6]) * sector_sz);
1814 	blk_queue_io_opt(sdkp->disk->queue,
1815 			 get_unaligned_be32(&buffer[12]) * sector_sz);
1816 
1817 	kfree(buffer);
1818 }
1819 
1820 /**
1821  * sd_read_block_characteristics - Query block dev. characteristics
1822  * @disk: disk to query
1823  */
1824 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
1825 {
1826 	char *buffer;
1827 	u16 rot;
1828 
1829 	/* Block Device Characteristics VPD */
1830 	buffer = scsi_get_vpd_page(sdkp->device, 0xb1);
1831 
1832 	if (buffer == NULL)
1833 		return;
1834 
1835 	rot = get_unaligned_be16(&buffer[4]);
1836 
1837 	if (rot == 1)
1838 		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
1839 
1840 	kfree(buffer);
1841 }
1842 
1843 static int sd_try_extended_inquiry(struct scsi_device *sdp)
1844 {
1845 	/*
1846 	 * Although VPD inquiries can go to SCSI-2 type devices,
1847 	 * some USB ones crash on receiving them, and the pages
1848 	 * we currently ask for are for SPC-3 and beyond
1849 	 */
1850 	if (sdp->scsi_level > SCSI_SPC_2)
1851 		return 1;
1852 	return 0;
1853 }
1854 
1855 /**
1856  *	sd_revalidate_disk - called the first time a new disk is seen,
1857  *	performs disk spin up, read_capacity, etc.
1858  *	@disk: struct gendisk we care about
1859  **/
1860 static int sd_revalidate_disk(struct gendisk *disk)
1861 {
1862 	struct scsi_disk *sdkp = scsi_disk(disk);
1863 	struct scsi_device *sdp = sdkp->device;
1864 	unsigned char *buffer;
1865 	unsigned ordered;
1866 
1867 	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
1868 				      "sd_revalidate_disk\n"));
1869 
1870 	/*
1871 	 * If the device is offline, don't try and read capacity or any
1872 	 * of the other niceties.
1873 	 */
1874 	if (!scsi_device_online(sdp))
1875 		goto out;
1876 
1877 	buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL);
1878 	if (!buffer) {
1879 		sd_printk(KERN_WARNING, sdkp, "sd_revalidate_disk: Memory "
1880 			  "allocation failure.\n");
1881 		goto out;
1882 	}
1883 
1884 	sd_spinup_disk(sdkp);
1885 
1886 	/*
1887 	 * Without media there is no reason to ask; moreover, some devices
1888 	 * react badly if we do.
1889 	 */
1890 	if (sdkp->media_present) {
1891 		sd_read_capacity(sdkp, buffer);
1892 
1893 		if (sd_try_extended_inquiry(sdp)) {
1894 			sd_read_block_limits(sdkp);
1895 			sd_read_block_characteristics(sdkp);
1896 		}
1897 
1898 		sd_read_write_protect_flag(sdkp, buffer);
1899 		sd_read_cache_type(sdkp, buffer);
1900 		sd_read_app_tag_own(sdkp, buffer);
1901 	}
1902 
1903 	sdkp->first_scan = 0;
1904 
1905 	/*
1906 	 * We now have all cache related info, determine how we deal
1907 	 * with ordered requests.  Note that as the current SCSI
1908 	 * dispatch function can alter request order, we cannot use
1909 	 * QUEUE_ORDERED_TAG_* even when ordered tag is supported.
1910 	 */
1911 	if (sdkp->WCE)
1912 		ordered = sdkp->DPOFUA
1913 			? QUEUE_ORDERED_DRAIN_FUA : QUEUE_ORDERED_DRAIN_FLUSH;
1914 	else
1915 		ordered = QUEUE_ORDERED_DRAIN;
1916 
1917 	blk_queue_ordered(sdkp->disk->queue, ordered, sd_prepare_flush);
1918 
1919 	set_capacity(disk, sdkp->capacity);
1920 	kfree(buffer);
1921 
1922  out:
1923 	return 0;
1924 }
1925 
1926 /**
1927  *	sd_format_disk_name - format disk name
1928  *	@prefix: name prefix - ie. "sd" for SCSI disks
1929  *	@index: index of the disk to format name for
1930  *	@buf: output buffer
1931  *	@buflen: length of the output buffer
1932  *
1933  *	SCSI disk names starts at sda.  The 26th device is sdz and the
1934  *	27th is sdaa.  The last one for two lettered suffix is sdzz
1935  *	which is followed by sdaaa.
1936  *
1937  *	This is basically 26 base counting with one extra 'nil' entry
1938  *	at the beggining from the second digit on and can be
1939  *	determined using similar method as 26 base conversion with the
1940  *	index shifted -1 after each digit is computed.
1941  *
1942  *	CONTEXT:
1943  *	Don't care.
1944  *
1945  *	RETURNS:
1946  *	0 on success, -errno on failure.
1947  */
1948 static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
1949 {
1950 	const int base = 'z' - 'a' + 1;
1951 	char *begin = buf + strlen(prefix);
1952 	char *end = buf + buflen;
1953 	char *p;
1954 	int unit;
1955 
1956 	p = end - 1;
1957 	*p = '\0';
1958 	unit = base;
1959 	do {
1960 		if (p == begin)
1961 			return -EINVAL;
1962 		*--p = 'a' + (index % unit);
1963 		index = (index / unit) - 1;
1964 	} while (index >= 0);
1965 
1966 	memmove(begin, p, end - p);
1967 	memcpy(buf, prefix, strlen(prefix));
1968 
1969 	return 0;
1970 }
1971 
1972 /*
1973  * The asynchronous part of sd_probe
1974  */
1975 static void sd_probe_async(void *data, async_cookie_t cookie)
1976 {
1977 	struct scsi_disk *sdkp = data;
1978 	struct scsi_device *sdp;
1979 	struct gendisk *gd;
1980 	u32 index;
1981 	struct device *dev;
1982 
1983 	sdp = sdkp->device;
1984 	gd = sdkp->disk;
1985 	index = sdkp->index;
1986 	dev = &sdp->sdev_gendev;
1987 
1988 	if (index < SD_MAX_DISKS) {
1989 		gd->major = sd_major((index & 0xf0) >> 4);
1990 		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
1991 		gd->minors = SD_MINORS;
1992 	}
1993 	gd->fops = &sd_fops;
1994 	gd->private_data = &sdkp->driver;
1995 	gd->queue = sdkp->device->request_queue;
1996 
1997 	/* defaults, until the device tells us otherwise */
1998 	sdp->sector_size = 512;
1999 	sdkp->capacity = 0;
2000 	sdkp->media_present = 1;
2001 	sdkp->write_prot = 0;
2002 	sdkp->WCE = 0;
2003 	sdkp->RCD = 0;
2004 	sdkp->ATO = 0;
2005 	sdkp->first_scan = 1;
2006 
2007 	sd_revalidate_disk(gd);
2008 
2009 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
2010 
2011 	gd->driverfs_dev = &sdp->sdev_gendev;
2012 	gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS;
2013 	if (sdp->removable)
2014 		gd->flags |= GENHD_FL_REMOVABLE;
2015 
2016 	dev_set_drvdata(dev, sdkp);
2017 	add_disk(gd);
2018 	sd_dif_config_host(sdkp);
2019 
2020 	sd_revalidate_disk(gd);
2021 
2022 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
2023 		  sdp->removable ? "removable " : "");
2024 	put_device(&sdkp->dev);
2025 }
2026 
2027 /**
2028  *	sd_probe - called during driver initialization and whenever a
2029  *	new scsi device is attached to the system. It is called once
2030  *	for each scsi device (not just disks) present.
2031  *	@dev: pointer to device object
2032  *
2033  *	Returns 0 if successful (or not interested in this scsi device
2034  *	(e.g. scanner)); 1 when there is an error.
2035  *
2036  *	Note: this function is invoked from the scsi mid-level.
2037  *	This function sets up the mapping between a given
2038  *	<host,channel,id,lun> (found in sdp) and new device name
2039  *	(e.g. /dev/sda). More precisely it is the block device major
2040  *	and minor number that is chosen here.
2041  *
2042  *	Assume sd_attach is not re-entrant (for time being)
2043  *	Also think about sd_attach() and sd_remove() running coincidentally.
2044  **/
2045 static int sd_probe(struct device *dev)
2046 {
2047 	struct scsi_device *sdp = to_scsi_device(dev);
2048 	struct scsi_disk *sdkp;
2049 	struct gendisk *gd;
2050 	u32 index;
2051 	int error;
2052 
2053 	error = -ENODEV;
2054 	if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != TYPE_RBC)
2055 		goto out;
2056 
2057 	SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
2058 					"sd_attach\n"));
2059 
2060 	error = -ENOMEM;
2061 	sdkp = kzalloc(sizeof(*sdkp), GFP_KERNEL);
2062 	if (!sdkp)
2063 		goto out;
2064 
2065 	gd = alloc_disk(SD_MINORS);
2066 	if (!gd)
2067 		goto out_free;
2068 
2069 	do {
2070 		if (!ida_pre_get(&sd_index_ida, GFP_KERNEL))
2071 			goto out_put;
2072 
2073 		spin_lock(&sd_index_lock);
2074 		error = ida_get_new(&sd_index_ida, &index);
2075 		spin_unlock(&sd_index_lock);
2076 	} while (error == -EAGAIN);
2077 
2078 	if (error)
2079 		goto out_put;
2080 
2081 	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
2082 	if (error)
2083 		goto out_free_index;
2084 
2085 	sdkp->device = sdp;
2086 	sdkp->driver = &sd_template;
2087 	sdkp->disk = gd;
2088 	sdkp->index = index;
2089 	sdkp->openers = 0;
2090 	sdkp->previous_state = 1;
2091 
2092 	if (!sdp->request_queue->rq_timeout) {
2093 		if (sdp->type != TYPE_MOD)
2094 			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
2095 		else
2096 			blk_queue_rq_timeout(sdp->request_queue,
2097 					     SD_MOD_TIMEOUT);
2098 	}
2099 
2100 	device_initialize(&sdkp->dev);
2101 	sdkp->dev.parent = &sdp->sdev_gendev;
2102 	sdkp->dev.class = &sd_disk_class;
2103 	dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
2104 
2105 	if (device_add(&sdkp->dev))
2106 		goto out_free_index;
2107 
2108 	get_device(&sdp->sdev_gendev);
2109 
2110 	get_device(&sdkp->dev);	/* prevent release before async_schedule */
2111 	async_schedule(sd_probe_async, sdkp);
2112 
2113 	return 0;
2114 
2115  out_free_index:
2116 	spin_lock(&sd_index_lock);
2117 	ida_remove(&sd_index_ida, index);
2118 	spin_unlock(&sd_index_lock);
2119  out_put:
2120 	put_disk(gd);
2121  out_free:
2122 	kfree(sdkp);
2123  out:
2124 	return error;
2125 }
2126 
2127 /**
2128  *	sd_remove - called whenever a scsi disk (previously recognized by
2129  *	sd_probe) is detached from the system. It is called (potentially
2130  *	multiple times) during sd module unload.
2131  *	@sdp: pointer to mid level scsi device object
2132  *
2133  *	Note: this function is invoked from the scsi mid-level.
2134  *	This function potentially frees up a device name (e.g. /dev/sdc)
2135  *	that could be re-used by a subsequent sd_probe().
2136  *	This function is not called when the built-in sd driver is "exit-ed".
2137  **/
2138 static int sd_remove(struct device *dev)
2139 {
2140 	struct scsi_disk *sdkp;
2141 
2142 	async_synchronize_full();
2143 	sdkp = dev_get_drvdata(dev);
2144 	blk_queue_prep_rq(sdkp->device->request_queue, scsi_prep_fn);
2145 	device_del(&sdkp->dev);
2146 	del_gendisk(sdkp->disk);
2147 	sd_shutdown(dev);
2148 
2149 	mutex_lock(&sd_ref_mutex);
2150 	dev_set_drvdata(dev, NULL);
2151 	put_device(&sdkp->dev);
2152 	mutex_unlock(&sd_ref_mutex);
2153 
2154 	return 0;
2155 }
2156 
2157 /**
2158  *	scsi_disk_release - Called to free the scsi_disk structure
2159  *	@dev: pointer to embedded class device
2160  *
2161  *	sd_ref_mutex must be held entering this routine.  Because it is
2162  *	called on last put, you should always use the scsi_disk_get()
2163  *	scsi_disk_put() helpers which manipulate the semaphore directly
2164  *	and never do a direct put_device.
2165  **/
2166 static void scsi_disk_release(struct device *dev)
2167 {
2168 	struct scsi_disk *sdkp = to_scsi_disk(dev);
2169 	struct gendisk *disk = sdkp->disk;
2170 
2171 	spin_lock(&sd_index_lock);
2172 	ida_remove(&sd_index_ida, sdkp->index);
2173 	spin_unlock(&sd_index_lock);
2174 
2175 	disk->private_data = NULL;
2176 	put_disk(disk);
2177 	put_device(&sdkp->device->sdev_gendev);
2178 
2179 	kfree(sdkp);
2180 }
2181 
2182 static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
2183 {
2184 	unsigned char cmd[6] = { START_STOP };	/* START_VALID */
2185 	struct scsi_sense_hdr sshdr;
2186 	struct scsi_device *sdp = sdkp->device;
2187 	int res;
2188 
2189 	if (start)
2190 		cmd[4] |= 1;	/* START */
2191 
2192 	if (sdp->start_stop_pwr_cond)
2193 		cmd[4] |= start ? 1 << 4 : 3 << 4;	/* Active or Standby */
2194 
2195 	if (!scsi_device_online(sdp))
2196 		return -ENODEV;
2197 
2198 	res = scsi_execute_req(sdp, cmd, DMA_NONE, NULL, 0, &sshdr,
2199 			       SD_TIMEOUT, SD_MAX_RETRIES, NULL);
2200 	if (res) {
2201 		sd_printk(KERN_WARNING, sdkp, "START_STOP FAILED\n");
2202 		sd_print_result(sdkp, res);
2203 		if (driver_byte(res) & DRIVER_SENSE)
2204 			sd_print_sense_hdr(sdkp, &sshdr);
2205 	}
2206 
2207 	return res;
2208 }
2209 
2210 /*
2211  * Send a SYNCHRONIZE CACHE instruction down to the device through
2212  * the normal SCSI command structure.  Wait for the command to
2213  * complete.
2214  */
2215 static void sd_shutdown(struct device *dev)
2216 {
2217 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2218 
2219 	if (!sdkp)
2220 		return;         /* this can happen */
2221 
2222 	if (sdkp->WCE) {
2223 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2224 		sd_sync_cache(sdkp);
2225 	}
2226 
2227 	if (system_state != SYSTEM_RESTART && sdkp->device->manage_start_stop) {
2228 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2229 		sd_start_stop_device(sdkp, 0);
2230 	}
2231 
2232 	scsi_disk_put(sdkp);
2233 }
2234 
2235 static int sd_suspend(struct device *dev, pm_message_t mesg)
2236 {
2237 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2238 	int ret = 0;
2239 
2240 	if (!sdkp)
2241 		return 0;	/* this can happen */
2242 
2243 	if (sdkp->WCE) {
2244 		sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n");
2245 		ret = sd_sync_cache(sdkp);
2246 		if (ret)
2247 			goto done;
2248 	}
2249 
2250 	if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
2251 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
2252 		ret = sd_start_stop_device(sdkp, 0);
2253 	}
2254 
2255 done:
2256 	scsi_disk_put(sdkp);
2257 	return ret;
2258 }
2259 
2260 static int sd_resume(struct device *dev)
2261 {
2262 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
2263 	int ret = 0;
2264 
2265 	if (!sdkp->device->manage_start_stop)
2266 		goto done;
2267 
2268 	sd_printk(KERN_NOTICE, sdkp, "Starting disk\n");
2269 	ret = sd_start_stop_device(sdkp, 1);
2270 
2271 done:
2272 	scsi_disk_put(sdkp);
2273 	return ret;
2274 }
2275 
2276 /**
2277  *	init_sd - entry point for this driver (both when built in or when
2278  *	a module).
2279  *
2280  *	Note: this function registers this driver with the scsi mid-level.
2281  **/
2282 static int __init init_sd(void)
2283 {
2284 	int majors = 0, i, err;
2285 
2286 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
2287 
2288 	for (i = 0; i < SD_MAJORS; i++)
2289 		if (register_blkdev(sd_major(i), "sd") == 0)
2290 			majors++;
2291 
2292 	if (!majors)
2293 		return -ENODEV;
2294 
2295 	err = class_register(&sd_disk_class);
2296 	if (err)
2297 		goto err_out;
2298 
2299 	err = scsi_register_driver(&sd_template.gendrv);
2300 	if (err)
2301 		goto err_out_class;
2302 
2303 	return 0;
2304 
2305 err_out_class:
2306 	class_unregister(&sd_disk_class);
2307 err_out:
2308 	for (i = 0; i < SD_MAJORS; i++)
2309 		unregister_blkdev(sd_major(i), "sd");
2310 	return err;
2311 }
2312 
2313 /**
2314  *	exit_sd - exit point for this driver (when it is a module).
2315  *
2316  *	Note: this function unregisters this driver from the scsi mid-level.
2317  **/
2318 static void __exit exit_sd(void)
2319 {
2320 	int i;
2321 
2322 	SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
2323 
2324 	scsi_unregister_driver(&sd_template.gendrv);
2325 	class_unregister(&sd_disk_class);
2326 
2327 	for (i = 0; i < SD_MAJORS; i++)
2328 		unregister_blkdev(sd_major(i), "sd");
2329 }
2330 
2331 module_init(init_sd);
2332 module_exit(exit_sd);
2333 
2334 static void sd_print_sense_hdr(struct scsi_disk *sdkp,
2335 			       struct scsi_sense_hdr *sshdr)
2336 {
2337 	sd_printk(KERN_INFO, sdkp, "");
2338 	scsi_show_sense_hdr(sshdr);
2339 	sd_printk(KERN_INFO, sdkp, "");
2340 	scsi_show_extd_sense(sshdr->asc, sshdr->ascq);
2341 }
2342 
2343 static void sd_print_result(struct scsi_disk *sdkp, int result)
2344 {
2345 	sd_printk(KERN_INFO, sdkp, "");
2346 	scsi_show_result(result);
2347 }
2348 
2349