xref: /linux/drivers/scsi/ch.c (revision 27c0f718d3b3c99e6d315308e95d987d0382a8a8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SCSI Media Changer device driver for Linux 2.6
4  *
5  *     (c) 1996-2003 Gerd Knorr <kraxel@bytesex.org>
6  *
7  */
8 
9 #define VERSION "0.25"
10 
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/fs.h>
14 #include <linux/kernel.h>
15 #include <linux/mm.h>
16 #include <linux/major.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/interrupt.h>
20 #include <linux/blkdev.h>
21 #include <linux/completion.h>
22 #include <linux/compat.h>
23 #include <linux/chio.h>			/* here are all the ioctls */
24 #include <linux/mutex.h>
25 #include <linux/idr.h>
26 #include <linux/slab.h>
27 
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_driver.h>
31 #include <scsi/scsi_ioctl.h>
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_eh.h>
35 #include <scsi/scsi_dbg.h>
36 
37 #define CH_DT_MAX       16
38 #define CH_TYPES        8
39 #define CH_MAX_DEVS     128
40 
41 MODULE_DESCRIPTION("device driver for scsi media changer devices");
42 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org>");
43 MODULE_LICENSE("GPL");
44 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_CHANGER_MAJOR);
45 MODULE_ALIAS_SCSI_DEVICE(TYPE_MEDIUM_CHANGER);
46 
47 static int init = 1;
48 module_param(init, int, 0444);
49 MODULE_PARM_DESC(init, \
50     "initialize element status on driver load (default: on)");
51 
52 static int timeout_move = 300;
53 module_param(timeout_move, int, 0644);
54 MODULE_PARM_DESC(timeout_move,"timeout for move commands "
55 		 "(default: 300 seconds)");
56 
57 static int timeout_init = 3600;
58 module_param(timeout_init, int, 0644);
59 MODULE_PARM_DESC(timeout_init,"timeout for INITIALIZE ELEMENT STATUS "
60 		 "(default: 3600 seconds)");
61 
62 static int verbose = 1;
63 module_param(verbose, int, 0644);
64 MODULE_PARM_DESC(verbose,"be verbose (default: on)");
65 
66 static int debug;
67 module_param(debug, int, 0644);
68 MODULE_PARM_DESC(debug,"enable/disable debug messages, also prints more "
69 		 "detailed sense codes on scsi errors (default: off)");
70 
71 static int dt_id[CH_DT_MAX] = { [ 0 ... (CH_DT_MAX-1) ] = -1 };
72 static int dt_lun[CH_DT_MAX];
73 module_param_array(dt_id,  int, NULL, 0444);
74 module_param_array(dt_lun, int, NULL, 0444);
75 
76 /* tell the driver about vendor-specific slots */
77 static int vendor_firsts[CH_TYPES-4];
78 static int vendor_counts[CH_TYPES-4];
79 module_param_array(vendor_firsts, int, NULL, 0444);
80 module_param_array(vendor_counts, int, NULL, 0444);
81 
82 static const char * vendor_labels[CH_TYPES-4] = {
83 	"v0", "v1", "v2", "v3"
84 };
85 // module_param_string_array(vendor_labels, NULL, 0444);
86 
87 #define ch_printk(prefix, ch, fmt, a...) \
88 	sdev_prefix_printk(prefix, (ch)->device, (ch)->name, fmt, ##a)
89 
90 #define DPRINTK(fmt, arg...)						\
91 do {									\
92 	if (debug)							\
93 		ch_printk(KERN_DEBUG, ch, fmt, ##arg);			\
94 } while (0)
95 #define VPRINTK(level, fmt, arg...)					\
96 do {									\
97 	if (verbose)							\
98 		ch_printk(level, ch, fmt, ##arg);			\
99 } while (0)
100 
101 /* ------------------------------------------------------------------- */
102 
103 #define MAX_RETRIES   1
104 
105 static const struct class ch_sysfs_class = {
106 	.name = "scsi_changer",
107 };
108 
109 typedef struct {
110 	struct kref         ref;
111 	struct list_head    list;
112 	int                 minor;
113 	char                name[8];
114 	struct scsi_device  *device;
115 	u_int               firsts[CH_TYPES];
116 	u_int               counts[CH_TYPES];
117 	u_int		    voltags;
118 	struct mutex	    lock;
119 } scsi_changer;
120 
121 static DEFINE_IDR(ch_index_idr);
122 static DEFINE_SPINLOCK(ch_index_lock);
123 
124 static const struct {
125 	unsigned char  sense;
126 	unsigned char  asc;
127 	unsigned char  ascq;
128 	int	       errno;
129 } ch_err[] = {
130 /* Just filled in what looks right. Hav'nt checked any standard paper for
131    these errno assignments, so they may be wrong... */
132 	{
133 		.sense  = ILLEGAL_REQUEST,
134 		.asc    = 0x21,
135 		.ascq   = 0x01,
136 		.errno  = EBADSLT, /* Invalid element address */
137 	},{
138 		.sense  = ILLEGAL_REQUEST,
139 		.asc    = 0x28,
140 		.ascq   = 0x01,
141 		.errno  = EBADE,   /* Import or export element accessed */
142 	},{
143 		.sense  = ILLEGAL_REQUEST,
144 		.asc    = 0x3B,
145 		.ascq   = 0x0D,
146 		.errno  = EXFULL,  /* Medium destination element full */
147 	},{
148 		.sense  = ILLEGAL_REQUEST,
149 		.asc    = 0x3B,
150 		.ascq   = 0x0E,
151 		.errno  = EBADE,   /* Medium source element empty */
152 	},{
153 		.sense  = ILLEGAL_REQUEST,
154 		.asc    = 0x20,
155 		.ascq   = 0x00,
156 		.errno  = EBADRQC, /* Invalid command operation code */
157 	},{
158 	        /* end of list */
159 	}
160 };
161 
162 /* ------------------------------------------------------------------- */
163 
164 static int ch_find_errno(struct scsi_sense_hdr *sshdr)
165 {
166 	int i,errno = 0;
167 
168 	/* Check to see if additional sense information is available */
169 	if (scsi_sense_valid(sshdr) &&
170 	    sshdr->asc != 0) {
171 		for (i = 0; ch_err[i].errno != 0; i++) {
172 			if (ch_err[i].sense == sshdr->sense_key &&
173 			    ch_err[i].asc   == sshdr->asc &&
174 			    ch_err[i].ascq  == sshdr->ascq) {
175 				errno = -ch_err[i].errno;
176 				break;
177 			}
178 		}
179 	}
180 	if (errno == 0)
181 		errno = -EIO;
182 	return errno;
183 }
184 
185 static int
186 ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
187 	   void *buffer, unsigned int buflength, enum req_op op)
188 {
189 	int errno = 0, timeout, result;
190 	struct scsi_sense_hdr sshdr;
191 	struct scsi_failure failure_defs[] = {
192 		{
193 			.sense = UNIT_ATTENTION,
194 			.asc = SCMD_FAILURE_ASC_ANY,
195 			.ascq = SCMD_FAILURE_ASCQ_ANY,
196 			.allowed = 3,
197 			.result = SAM_STAT_CHECK_CONDITION,
198 		},
199 		{}
200 	};
201 	struct scsi_failures failures = {
202 		.failure_definitions = failure_defs,
203 	};
204 	const struct scsi_exec_args exec_args = {
205 		.sshdr = &sshdr,
206 		.failures = &failures,
207 	};
208 
209 	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
210 		? timeout_init : timeout_move;
211 
212 	result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
213 				  timeout * HZ, MAX_RETRIES, &exec_args);
214 	if (result < 0)
215 		return result;
216 	if (scsi_sense_valid(&sshdr)) {
217 		if (debug)
218 			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
219 		errno = ch_find_errno(&sshdr);
220 	}
221 	return errno;
222 }
223 
224 /* ------------------------------------------------------------------------ */
225 
226 static int
227 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
228 {
229 	int i;
230 
231 	for (i = 0; i < CH_TYPES; i++) {
232 		if (elem >= ch->firsts[i]  &&
233 		    elem <  ch->firsts[i] +
234 	            ch->counts[i])
235 			return i+1;
236 	}
237 	return 0;
238 }
239 
240 static int
241 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
242 {
243 	u_char  cmd[12];
244 	u_char  *buffer;
245 	int     result;
246 
247 	buffer = kmalloc(512, GFP_KERNEL);
248 	if(!buffer)
249 		return -ENOMEM;
250 
251  retry:
252 	memset(cmd,0,sizeof(cmd));
253 	cmd[0] = READ_ELEMENT_STATUS;
254 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
255 		(ch->voltags ? 0x10 : 0) |
256 		ch_elem_to_typecode(ch,elem);
257 	cmd[2] = (elem >> 8) & 0xff;
258 	cmd[3] = elem        & 0xff;
259 	cmd[5] = 1;
260 	cmd[9] = 255;
261 	if (0 == (result = ch_do_scsi(ch, cmd, 12,
262 				      buffer, 256, REQ_OP_DRV_IN))) {
263 		if (((buffer[16] << 8) | buffer[17]) != elem) {
264 			DPRINTK("asked for element 0x%02x, got 0x%02x\n",
265 				elem,(buffer[16] << 8) | buffer[17]);
266 			kfree(buffer);
267 			return -EIO;
268 		}
269 		memcpy(data,buffer+16,16);
270 	} else {
271 		if (ch->voltags) {
272 			ch->voltags = 0;
273 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
274 			goto retry;
275 		}
276 		DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
277 	}
278 	kfree(buffer);
279 	return result;
280 }
281 
282 static int
283 ch_init_elem(scsi_changer *ch)
284 {
285 	int err;
286 	u_char cmd[6];
287 
288 	VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
289 	memset(cmd,0,sizeof(cmd));
290 	cmd[0] = INITIALIZE_ELEMENT_STATUS;
291 	cmd[1] = (ch->device->lun & 0x7) << 5;
292 	err = ch_do_scsi(ch, cmd, 6, NULL, 0, REQ_OP_DRV_IN);
293 	VPRINTK(KERN_INFO, "... finished\n");
294 	return err;
295 }
296 
297 static int
298 ch_readconfig(scsi_changer *ch)
299 {
300 	u_char  cmd[10], data[16];
301 	u_char  *buffer;
302 	int     result,id,lun,i;
303 	u_int   elem;
304 
305 	buffer = kzalloc(512, GFP_KERNEL);
306 	if (!buffer)
307 		return -ENOMEM;
308 
309 	memset(cmd,0,sizeof(cmd));
310 	cmd[0] = MODE_SENSE;
311 	cmd[1] = (ch->device->lun & 0x7) << 5;
312 	cmd[2] = 0x1d;
313 	cmd[4] = 255;
314 	result = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
315 	if (0 != result) {
316 		cmd[1] |= (1<<3);
317 		result  = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
318 	}
319 	if (0 == result) {
320 		ch->firsts[CHET_MT] =
321 			(buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
322 		ch->counts[CHET_MT] =
323 			(buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
324 		ch->firsts[CHET_ST] =
325 			(buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
326 		ch->counts[CHET_ST] =
327 			(buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
328 		ch->firsts[CHET_IE] =
329 			(buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
330 		ch->counts[CHET_IE] =
331 			(buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
332 		ch->firsts[CHET_DT] =
333 			(buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
334 		ch->counts[CHET_DT] =
335 			(buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
336 		VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
337 			ch->firsts[CHET_MT],
338 			ch->counts[CHET_MT]);
339 		VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
340 			ch->firsts[CHET_ST],
341 			ch->counts[CHET_ST]);
342 		VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
343 			ch->firsts[CHET_IE],
344 			ch->counts[CHET_IE]);
345 		VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
346 			ch->firsts[CHET_DT],
347 			ch->counts[CHET_DT]);
348 	} else {
349 		VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
350 	}
351 
352 	/* vendor specific element types */
353 	for (i = 0; i < 4; i++) {
354 		if (0 == vendor_counts[i])
355 			continue;
356 		if (NULL == vendor_labels[i])
357 			continue;
358 		ch->firsts[CHET_V1+i] = vendor_firsts[i];
359 		ch->counts[CHET_V1+i] = vendor_counts[i];
360 		VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
361 			i+5,i+1,vendor_firsts[i],vendor_counts[i],
362 			vendor_labels[i]);
363 	}
364 
365 	/* report the devices of the data transfer elements */
366 	for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
367 		struct scsi_device *sdev;
368 
369 		id  = -1;
370 		lun = 0;
371 		if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
372 			id  = dt_id[elem];
373 			lun = dt_lun[elem];
374 			VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
375 				elem+ch->firsts[CHET_DT]);
376 		} else if (0 != ch_read_element_status
377 			   (ch,elem+ch->firsts[CHET_DT],data)) {
378 			VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
379 				elem+ch->firsts[CHET_DT]);
380 		} else {
381 			VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
382 			if (data[6] & 0x80) {
383 				VPRINTK(KERN_CONT, "not this SCSI bus\n");
384 			} else if (0 == (data[6] & 0x30)) {
385 				VPRINTK(KERN_CONT, "ID/LUN unknown\n");
386 			} else {
387 				id  = ch->device->id;
388 				lun = 0;
389 				if (data[6] & 0x20) id  = data[7];
390 				if (data[6] & 0x10) lun = data[6] & 7;
391 			}
392 		}
393 		if (-1 != id) {
394 			VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
395 			sdev = scsi_device_lookup(ch->device->host,
396 						  ch->device->channel,
397 						  id, lun);
398 			if (!sdev) {
399 				/* should not happen */
400 				VPRINTK(KERN_CONT, "Huh? device not found!\n");
401 			} else {
402 				VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
403 					sdev->vendor, sdev->model, sdev->rev);
404 				scsi_device_put(sdev);
405 			}
406 		}
407 	}
408 	ch->voltags = 1;
409 	kfree(buffer);
410 
411 	return 0;
412 }
413 
414 /* ------------------------------------------------------------------------ */
415 
416 static int
417 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
418 {
419 	u_char  cmd[10];
420 
421 	DPRINTK("position: 0x%x\n",elem);
422 	if (0 == trans)
423 		trans = ch->firsts[CHET_MT];
424 	memset(cmd,0,sizeof(cmd));
425 	cmd[0]  = POSITION_TO_ELEMENT;
426 	cmd[1]  = (ch->device->lun & 0x7) << 5;
427 	cmd[2]  = (trans >> 8) & 0xff;
428 	cmd[3]  =  trans       & 0xff;
429 	cmd[4]  = (elem  >> 8) & 0xff;
430 	cmd[5]  =  elem        & 0xff;
431 	cmd[8]  = rotate ? 1 : 0;
432 	return ch_do_scsi(ch, cmd, 10, NULL, 0, REQ_OP_DRV_IN);
433 }
434 
435 static int
436 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
437 {
438 	u_char  cmd[12];
439 
440 	DPRINTK("move: 0x%x => 0x%x\n",src,dest);
441 	if (0 == trans)
442 		trans = ch->firsts[CHET_MT];
443 	memset(cmd,0,sizeof(cmd));
444 	cmd[0]  = MOVE_MEDIUM;
445 	cmd[1]  = (ch->device->lun & 0x7) << 5;
446 	cmd[2]  = (trans >> 8) & 0xff;
447 	cmd[3]  =  trans       & 0xff;
448 	cmd[4]  = (src   >> 8) & 0xff;
449 	cmd[5]  =  src         & 0xff;
450 	cmd[6]  = (dest  >> 8) & 0xff;
451 	cmd[7]  =  dest        & 0xff;
452 	cmd[10] = rotate ? 1 : 0;
453 	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
454 }
455 
456 static int
457 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
458 	    u_int dest1, u_int dest2, int rotate1, int rotate2)
459 {
460 	u_char  cmd[12];
461 
462 	DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
463 		src,dest1,dest2);
464 	if (0 == trans)
465 		trans = ch->firsts[CHET_MT];
466 	memset(cmd,0,sizeof(cmd));
467 	cmd[0]  = EXCHANGE_MEDIUM;
468 	cmd[1]  = (ch->device->lun & 0x7) << 5;
469 	cmd[2]  = (trans >> 8) & 0xff;
470 	cmd[3]  =  trans       & 0xff;
471 	cmd[4]  = (src   >> 8) & 0xff;
472 	cmd[5]  =  src         & 0xff;
473 	cmd[6]  = (dest1 >> 8) & 0xff;
474 	cmd[7]  =  dest1       & 0xff;
475 	cmd[8]  = (dest2 >> 8) & 0xff;
476 	cmd[9]  =  dest2       & 0xff;
477 	cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
478 
479 	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
480 }
481 
482 static void
483 ch_check_voltag(char *tag)
484 {
485 	int i;
486 
487 	for (i = 0; i < 32; i++) {
488 		/* restrict to ascii */
489 		if (tag[i] >= 0x7f || tag[i] < 0x20)
490 			tag[i] = ' ';
491 		/* don't allow search wildcards */
492 		if (tag[i] == '?' ||
493 		    tag[i] == '*')
494 			tag[i] = ' ';
495 	}
496 }
497 
498 static int
499 ch_set_voltag(scsi_changer *ch, u_int elem,
500 	      int alternate, int clear, u_char *tag)
501 {
502 	u_char  cmd[12];
503 	u_char  *buffer;
504 	int result;
505 
506 	buffer = kzalloc(512, GFP_KERNEL);
507 	if (!buffer)
508 		return -ENOMEM;
509 
510 	DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
511 		clear     ? "clear"     : "set",
512 		alternate ? "alternate" : "primary",
513 		elem, tag);
514 	memset(cmd,0,sizeof(cmd));
515 	cmd[0]  = SEND_VOLUME_TAG;
516 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
517 		ch_elem_to_typecode(ch,elem);
518 	cmd[2] = (elem >> 8) & 0xff;
519 	cmd[3] = elem        & 0xff;
520 	cmd[5] = clear
521 		? (alternate ? 0x0d : 0x0c)
522 		: (alternate ? 0x0b : 0x0a);
523 
524 	cmd[9] = 255;
525 
526 	memcpy(buffer,tag,32);
527 	ch_check_voltag(buffer);
528 
529 	result = ch_do_scsi(ch, cmd, 12, buffer, 256, REQ_OP_DRV_OUT);
530 	kfree(buffer);
531 	return result;
532 }
533 
534 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
535 {
536 	int retval = 0;
537 	u_char data[16];
538 	unsigned int i;
539 
540 	mutex_lock(&ch->lock);
541 	for (i = 0; i < ch->counts[type]; i++) {
542 		if (0 != ch_read_element_status
543 		    (ch, ch->firsts[type]+i,data)) {
544 			retval = -EIO;
545 			break;
546 		}
547 		put_user(data[2], dest+i);
548 		if (data[2] & CESTATUS_EXCEPT)
549 			VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
550 				ch->firsts[type]+i,
551 				(int)data[4],(int)data[5]);
552 		retval = ch_read_element_status
553 			(ch, ch->firsts[type]+i,data);
554 		if (0 != retval)
555 			break;
556 	}
557 	mutex_unlock(&ch->lock);
558 	return retval;
559 }
560 
561 /* ------------------------------------------------------------------------ */
562 
563 static void ch_destroy(struct kref *ref)
564 {
565 	scsi_changer *ch = container_of(ref, scsi_changer, ref);
566 
567 	ch->device = NULL;
568 	kfree(ch);
569 }
570 
571 static int
572 ch_release(struct inode *inode, struct file *file)
573 {
574 	scsi_changer *ch = file->private_data;
575 
576 	scsi_device_put(ch->device);
577 	file->private_data = NULL;
578 	kref_put(&ch->ref, ch_destroy);
579 	return 0;
580 }
581 
582 static int
583 ch_open(struct inode *inode, struct file *file)
584 {
585 	scsi_changer *ch;
586 	int minor = iminor(inode);
587 
588 	spin_lock(&ch_index_lock);
589 	ch = idr_find(&ch_index_idr, minor);
590 
591 	if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
592 		spin_unlock(&ch_index_lock);
593 		return -ENXIO;
594 	}
595 	spin_unlock(&ch_index_lock);
596 	if (scsi_device_get(ch->device)) {
597 		kref_put(&ch->ref, ch_destroy);
598 		return -ENXIO;
599 	}
600 	/* Synchronize with ch_probe() */
601 	mutex_lock(&ch->lock);
602 	file->private_data = ch;
603 	mutex_unlock(&ch->lock);
604 	return 0;
605 }
606 
607 static int
608 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
609 {
610 	if (type >= CH_TYPES  ||  unit >= ch->counts[type])
611 		return -1;
612 	return 0;
613 }
614 
615 struct changer_element_status32 {
616 	int		ces_type;
617 	compat_uptr_t	ces_data;
618 };
619 #define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
620 
621 static long ch_ioctl(struct file *file,
622 		    unsigned int cmd, unsigned long arg)
623 {
624 	scsi_changer *ch = file->private_data;
625 	int retval;
626 	void __user *argp = (void __user *)arg;
627 
628 	retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
629 			file->f_flags & O_NDELAY);
630 	if (retval)
631 		return retval;
632 
633 	switch (cmd) {
634 	case CHIOGPARAMS:
635 	{
636 		struct changer_params params;
637 
638 		params.cp_curpicker = 0;
639 		params.cp_npickers  = ch->counts[CHET_MT];
640 		params.cp_nslots    = ch->counts[CHET_ST];
641 		params.cp_nportals  = ch->counts[CHET_IE];
642 		params.cp_ndrives   = ch->counts[CHET_DT];
643 
644 		if (copy_to_user(argp, &params, sizeof(params)))
645 			return -EFAULT;
646 		return 0;
647 	}
648 	case CHIOGVPARAMS:
649 	{
650 		struct changer_vendor_params vparams;
651 
652 		memset(&vparams,0,sizeof(vparams));
653 		if (ch->counts[CHET_V1]) {
654 			vparams.cvp_n1  = ch->counts[CHET_V1];
655 			strscpy(vparams.cvp_label1, vendor_labels[0],
656 				sizeof(vparams.cvp_label1));
657 		}
658 		if (ch->counts[CHET_V2]) {
659 			vparams.cvp_n2  = ch->counts[CHET_V2];
660 			strscpy(vparams.cvp_label2, vendor_labels[1],
661 				sizeof(vparams.cvp_label2));
662 		}
663 		if (ch->counts[CHET_V3]) {
664 			vparams.cvp_n3  = ch->counts[CHET_V3];
665 			strscpy(vparams.cvp_label3, vendor_labels[2],
666 				sizeof(vparams.cvp_label3));
667 		}
668 		if (ch->counts[CHET_V4]) {
669 			vparams.cvp_n4  = ch->counts[CHET_V4];
670 			strscpy(vparams.cvp_label4, vendor_labels[3],
671 				sizeof(vparams.cvp_label4));
672 		}
673 		if (copy_to_user(argp, &vparams, sizeof(vparams)))
674 			return -EFAULT;
675 		return 0;
676 	}
677 
678 	case CHIOPOSITION:
679 	{
680 		struct changer_position pos;
681 
682 		if (copy_from_user(&pos, argp, sizeof (pos)))
683 			return -EFAULT;
684 
685 		if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
686 			DPRINTK("CHIOPOSITION: invalid parameter\n");
687 			return -EBADSLT;
688 		}
689 		mutex_lock(&ch->lock);
690 		retval = ch_position(ch,0,
691 				     ch->firsts[pos.cp_type] + pos.cp_unit,
692 				     pos.cp_flags & CP_INVERT);
693 		mutex_unlock(&ch->lock);
694 		return retval;
695 	}
696 
697 	case CHIOMOVE:
698 	{
699 		struct changer_move mv;
700 
701 		if (copy_from_user(&mv, argp, sizeof (mv)))
702 			return -EFAULT;
703 
704 		if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
705 		    0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
706 			DPRINTK("CHIOMOVE: invalid parameter\n");
707 			return -EBADSLT;
708 		}
709 
710 		mutex_lock(&ch->lock);
711 		retval = ch_move(ch,0,
712 				 ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
713 				 ch->firsts[mv.cm_totype]   + mv.cm_tounit,
714 				 mv.cm_flags & CM_INVERT);
715 		mutex_unlock(&ch->lock);
716 		return retval;
717 	}
718 
719 	case CHIOEXCHANGE:
720 	{
721 		struct changer_exchange mv;
722 
723 		if (copy_from_user(&mv, argp, sizeof (mv)))
724 			return -EFAULT;
725 
726 		if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
727 		    0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
728 		    0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
729 			DPRINTK("CHIOEXCHANGE: invalid parameter\n");
730 			return -EBADSLT;
731 		}
732 
733 		mutex_lock(&ch->lock);
734 		retval = ch_exchange
735 			(ch,0,
736 			 ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
737 			 ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
738 			 ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
739 			 mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
740 		mutex_unlock(&ch->lock);
741 		return retval;
742 	}
743 
744 	case CHIOGSTATUS:
745 	{
746 		struct changer_element_status ces;
747 
748 		if (copy_from_user(&ces, argp, sizeof (ces)))
749 			return -EFAULT;
750 		if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
751 			return -EINVAL;
752 
753 		return ch_gstatus(ch, ces.ces_type, ces.ces_data);
754 	}
755 #ifdef CONFIG_COMPAT
756 	case CHIOGSTATUS32:
757 	{
758 		struct changer_element_status32 ces32;
759 
760 		if (copy_from_user(&ces32, argp, sizeof(ces32)))
761 			return -EFAULT;
762 		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
763 			return -EINVAL;
764 
765 		return ch_gstatus(ch, ces32.ces_type,
766 				  compat_ptr(ces32.ces_data));
767 	}
768 #endif
769 	case CHIOGELEM:
770 	{
771 		struct changer_get_element cge;
772 		u_char ch_cmd[12];
773 		u_char *buffer;
774 		unsigned int elem;
775 		int     result,i;
776 
777 		if (copy_from_user(&cge, argp, sizeof (cge)))
778 			return -EFAULT;
779 
780 		if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
781 			return -EINVAL;
782 		elem = ch->firsts[cge.cge_type] + cge.cge_unit;
783 
784 		buffer = kmalloc(512, GFP_KERNEL);
785 		if (!buffer)
786 			return -ENOMEM;
787 		mutex_lock(&ch->lock);
788 
789 	voltag_retry:
790 		memset(ch_cmd, 0, sizeof(ch_cmd));
791 		ch_cmd[0] = READ_ELEMENT_STATUS;
792 		ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
793 			(ch->voltags ? 0x10 : 0) |
794 			ch_elem_to_typecode(ch,elem);
795 		ch_cmd[2] = (elem >> 8) & 0xff;
796 		ch_cmd[3] = elem        & 0xff;
797 		ch_cmd[5] = 1;
798 		ch_cmd[9] = 255;
799 
800 		result = ch_do_scsi(ch, ch_cmd, 12, buffer, 256, REQ_OP_DRV_IN);
801 		if (!result) {
802 			cge.cge_status = buffer[18];
803 			cge.cge_flags = 0;
804 			if (buffer[18] & CESTATUS_EXCEPT) {
805 				cge.cge_errno = EIO;
806 			}
807 			if (buffer[25] & 0x80) {
808 				cge.cge_flags |= CGE_SRC;
809 				if (buffer[25] & 0x40)
810 					cge.cge_flags |= CGE_INVERT;
811 				elem = (buffer[26]<<8) | buffer[27];
812 				for (i = 0; i < 4; i++) {
813 					if (elem >= ch->firsts[i] &&
814 					    elem <  ch->firsts[i] + ch->counts[i]) {
815 						cge.cge_srctype = i;
816 						cge.cge_srcunit = elem-ch->firsts[i];
817 					}
818 				}
819 			}
820 			if ((buffer[22] & 0x30) == 0x30) {
821 				cge.cge_flags |= CGE_IDLUN;
822 				cge.cge_id  = buffer[23];
823 				cge.cge_lun = buffer[22] & 7;
824 			}
825 			if (buffer[9] & 0x80) {
826 				cge.cge_flags |= CGE_PVOLTAG;
827 				memcpy(cge.cge_pvoltag,buffer+28,36);
828 			}
829 			if (buffer[9] & 0x40) {
830 				cge.cge_flags |= CGE_AVOLTAG;
831 				memcpy(cge.cge_avoltag,buffer+64,36);
832 			}
833 		} else if (ch->voltags) {
834 			ch->voltags = 0;
835 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
836 			goto voltag_retry;
837 		}
838 		kfree(buffer);
839 		mutex_unlock(&ch->lock);
840 
841 		if (copy_to_user(argp, &cge, sizeof (cge)))
842 			return -EFAULT;
843 		return result;
844 	}
845 
846 	case CHIOINITELEM:
847 	{
848 		mutex_lock(&ch->lock);
849 		retval = ch_init_elem(ch);
850 		mutex_unlock(&ch->lock);
851 		return retval;
852 	}
853 
854 	case CHIOSVOLTAG:
855 	{
856 		struct changer_set_voltag csv;
857 		int elem;
858 
859 		if (copy_from_user(&csv, argp, sizeof(csv)))
860 			return -EFAULT;
861 
862 		if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
863 			DPRINTK("CHIOSVOLTAG: invalid parameter\n");
864 			return -EBADSLT;
865 		}
866 		elem = ch->firsts[csv.csv_type] + csv.csv_unit;
867 		mutex_lock(&ch->lock);
868 		retval = ch_set_voltag(ch, elem,
869 				       csv.csv_flags & CSV_AVOLTAG,
870 				       csv.csv_flags & CSV_CLEARTAG,
871 				       csv.csv_voltag);
872 		mutex_unlock(&ch->lock);
873 		return retval;
874 	}
875 
876 	default:
877 		return scsi_ioctl(ch->device, file->f_mode & FMODE_WRITE, cmd,
878 				  argp);
879 
880 	}
881 }
882 
883 /* ------------------------------------------------------------------------ */
884 
885 static int ch_probe(struct scsi_device *sd)
886 {
887 	struct device *dev = &sd->sdev_gendev;
888 	struct device *class_dev;
889 	int ret;
890 	scsi_changer *ch;
891 
892 	if (sd->type != TYPE_MEDIUM_CHANGER)
893 		return -ENODEV;
894 
895 	ch = kzalloc_obj(*ch);
896 	if (NULL == ch)
897 		return -ENOMEM;
898 
899 	idr_preload(GFP_KERNEL);
900 	spin_lock(&ch_index_lock);
901 	ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
902 	spin_unlock(&ch_index_lock);
903 	idr_preload_end();
904 
905 	if (ret < 0) {
906 		if (ret == -ENOSPC)
907 			ret = -ENODEV;
908 		goto free_ch;
909 	}
910 
911 	ch->minor = ret;
912 	sprintf(ch->name,"ch%d",ch->minor);
913 	ret = scsi_device_get(sd);
914 	if (ret) {
915 		sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
916 			    ch->minor);
917 		goto remove_idr;
918 	}
919 
920 	mutex_init(&ch->lock);
921 	kref_init(&ch->ref);
922 	ch->device = sd;
923 	class_dev = device_create(&ch_sysfs_class, dev,
924 				  MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
925 				  "s%s", ch->name);
926 	if (IS_ERR(class_dev)) {
927 		sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
928 			    ch->minor);
929 		ret = PTR_ERR(class_dev);
930 		goto put_device;
931 	}
932 
933 	mutex_lock(&ch->lock);
934 	ret = ch_readconfig(ch);
935 	if (ret) {
936 		mutex_unlock(&ch->lock);
937 		goto destroy_dev;
938 	}
939 	if (init)
940 		ch_init_elem(ch);
941 
942 	mutex_unlock(&ch->lock);
943 	dev_set_drvdata(dev, ch);
944 	sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
945 
946 	return 0;
947 destroy_dev:
948 	device_destroy(&ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
949 put_device:
950 	scsi_device_put(sd);
951 remove_idr:
952 	idr_remove(&ch_index_idr, ch->minor);
953 free_ch:
954 	kfree(ch);
955 	return ret;
956 }
957 
958 static void ch_remove(struct scsi_device *sd)
959 {
960 	struct device *dev = &sd->sdev_gendev;
961 	scsi_changer *ch = dev_get_drvdata(dev);
962 
963 	spin_lock(&ch_index_lock);
964 	idr_remove(&ch_index_idr, ch->minor);
965 	dev_set_drvdata(dev, NULL);
966 	spin_unlock(&ch_index_lock);
967 
968 	device_destroy(&ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
969 	scsi_device_put(ch->device);
970 	kref_put(&ch->ref, ch_destroy);
971 }
972 
973 static struct scsi_driver ch_template = {
974 	.probe = ch_probe,
975 	.remove = ch_remove,
976 	.gendrv = {
977 		.name	= "ch",
978 		.owner	= THIS_MODULE,
979 	},
980 };
981 
982 static const struct file_operations changer_fops = {
983 	.owner		= THIS_MODULE,
984 	.open		= ch_open,
985 	.release	= ch_release,
986 	.unlocked_ioctl	= ch_ioctl,
987 	.compat_ioctl	= compat_ptr_ioctl,
988 	.llseek		= noop_llseek,
989 };
990 
991 static int __init init_ch_module(void)
992 {
993 	int rc;
994 
995 	printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
996 	rc = class_register(&ch_sysfs_class);
997 	if (rc)
998 		return rc;
999 	rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1000 	if (rc < 0) {
1001 		printk("Unable to get major %d for SCSI-Changer\n",
1002 		       SCSI_CHANGER_MAJOR);
1003 		goto fail1;
1004 	}
1005 	rc = scsi_register_driver(&ch_template);
1006 	if (rc < 0)
1007 		goto fail2;
1008 	return 0;
1009 
1010  fail2:
1011 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1012  fail1:
1013 	class_unregister(&ch_sysfs_class);
1014 	return rc;
1015 }
1016 
1017 static void __exit exit_ch_module(void)
1018 {
1019 	scsi_unregister_driver(&ch_template);
1020 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1021 	class_unregister(&ch_sysfs_class);
1022 	idr_destroy(&ch_index_idr);
1023 }
1024 
1025 module_init(init_ch_module);
1026 module_exit(exit_ch_module);
1027