xref: /linux/drivers/scsi/ch.c (revision f82811e22b480a203a438d8e1f29af9c93ccbb0c)
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 struct class * ch_sysfs_class;
106 
107 typedef struct {
108 	struct kref         ref;
109 	struct list_head    list;
110 	int                 minor;
111 	char                name[8];
112 	struct scsi_device  *device;
113 	struct scsi_device  **dt;        /* ptrs to data transfer elements */
114 	u_int               firsts[CH_TYPES];
115 	u_int               counts[CH_TYPES];
116 	u_int               unit_attention;
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, retries = 0, timeout, result;
190 	struct scsi_sense_hdr sshdr;
191 	const struct scsi_exec_args exec_args = {
192 		.sshdr = &sshdr,
193 	};
194 
195 	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
196 		? timeout_init : timeout_move;
197 
198  retry:
199 	errno = 0;
200 	result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
201 				  timeout * HZ, MAX_RETRIES, &exec_args);
202 	if (result < 0)
203 		return result;
204 	if (scsi_sense_valid(&sshdr)) {
205 		if (debug)
206 			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
207 		errno = ch_find_errno(&sshdr);
208 
209 		switch(sshdr.sense_key) {
210 		case UNIT_ATTENTION:
211 			ch->unit_attention = 1;
212 			if (retries++ < 3)
213 				goto retry;
214 			break;
215 		}
216 	}
217 	return errno;
218 }
219 
220 /* ------------------------------------------------------------------------ */
221 
222 static int
223 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
224 {
225 	int i;
226 
227 	for (i = 0; i < CH_TYPES; i++) {
228 		if (elem >= ch->firsts[i]  &&
229 		    elem <  ch->firsts[i] +
230 	            ch->counts[i])
231 			return i+1;
232 	}
233 	return 0;
234 }
235 
236 static int
237 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
238 {
239 	u_char  cmd[12];
240 	u_char  *buffer;
241 	int     result;
242 
243 	buffer = kmalloc(512, GFP_KERNEL);
244 	if(!buffer)
245 		return -ENOMEM;
246 
247  retry:
248 	memset(cmd,0,sizeof(cmd));
249 	cmd[0] = READ_ELEMENT_STATUS;
250 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
251 		(ch->voltags ? 0x10 : 0) |
252 		ch_elem_to_typecode(ch,elem);
253 	cmd[2] = (elem >> 8) & 0xff;
254 	cmd[3] = elem        & 0xff;
255 	cmd[5] = 1;
256 	cmd[9] = 255;
257 	if (0 == (result = ch_do_scsi(ch, cmd, 12,
258 				      buffer, 256, REQ_OP_DRV_IN))) {
259 		if (((buffer[16] << 8) | buffer[17]) != elem) {
260 			DPRINTK("asked for element 0x%02x, got 0x%02x\n",
261 				elem,(buffer[16] << 8) | buffer[17]);
262 			kfree(buffer);
263 			return -EIO;
264 		}
265 		memcpy(data,buffer+16,16);
266 	} else {
267 		if (ch->voltags) {
268 			ch->voltags = 0;
269 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
270 			goto retry;
271 		}
272 		DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
273 	}
274 	kfree(buffer);
275 	return result;
276 }
277 
278 static int
279 ch_init_elem(scsi_changer *ch)
280 {
281 	int err;
282 	u_char cmd[6];
283 
284 	VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
285 	memset(cmd,0,sizeof(cmd));
286 	cmd[0] = INITIALIZE_ELEMENT_STATUS;
287 	cmd[1] = (ch->device->lun & 0x7) << 5;
288 	err = ch_do_scsi(ch, cmd, 6, NULL, 0, REQ_OP_DRV_IN);
289 	VPRINTK(KERN_INFO, "... finished\n");
290 	return err;
291 }
292 
293 static int
294 ch_readconfig(scsi_changer *ch)
295 {
296 	u_char  cmd[10], data[16];
297 	u_char  *buffer;
298 	int     result,id,lun,i;
299 	u_int   elem;
300 
301 	buffer = kzalloc(512, GFP_KERNEL);
302 	if (!buffer)
303 		return -ENOMEM;
304 
305 	memset(cmd,0,sizeof(cmd));
306 	cmd[0] = MODE_SENSE;
307 	cmd[1] = (ch->device->lun & 0x7) << 5;
308 	cmd[2] = 0x1d;
309 	cmd[4] = 255;
310 	result = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
311 	if (0 != result) {
312 		cmd[1] |= (1<<3);
313 		result  = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
314 	}
315 	if (0 == result) {
316 		ch->firsts[CHET_MT] =
317 			(buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
318 		ch->counts[CHET_MT] =
319 			(buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
320 		ch->firsts[CHET_ST] =
321 			(buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
322 		ch->counts[CHET_ST] =
323 			(buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
324 		ch->firsts[CHET_IE] =
325 			(buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
326 		ch->counts[CHET_IE] =
327 			(buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
328 		ch->firsts[CHET_DT] =
329 			(buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
330 		ch->counts[CHET_DT] =
331 			(buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
332 		VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
333 			ch->firsts[CHET_MT],
334 			ch->counts[CHET_MT]);
335 		VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
336 			ch->firsts[CHET_ST],
337 			ch->counts[CHET_ST]);
338 		VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
339 			ch->firsts[CHET_IE],
340 			ch->counts[CHET_IE]);
341 		VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
342 			ch->firsts[CHET_DT],
343 			ch->counts[CHET_DT]);
344 	} else {
345 		VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
346 	}
347 
348 	/* vendor specific element types */
349 	for (i = 0; i < 4; i++) {
350 		if (0 == vendor_counts[i])
351 			continue;
352 		if (NULL == vendor_labels[i])
353 			continue;
354 		ch->firsts[CHET_V1+i] = vendor_firsts[i];
355 		ch->counts[CHET_V1+i] = vendor_counts[i];
356 		VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
357 			i+5,i+1,vendor_firsts[i],vendor_counts[i],
358 			vendor_labels[i]);
359 	}
360 
361 	/* look up the devices of the data transfer elements */
362 	ch->dt = kcalloc(ch->counts[CHET_DT], sizeof(*ch->dt),
363 			 GFP_KERNEL);
364 
365 	if (!ch->dt) {
366 		kfree(buffer);
367 		return -ENOMEM;
368 	}
369 
370 	for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
371 		id  = -1;
372 		lun = 0;
373 		if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
374 			id  = dt_id[elem];
375 			lun = dt_lun[elem];
376 			VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
377 				elem+ch->firsts[CHET_DT]);
378 		} else if (0 != ch_read_element_status
379 			   (ch,elem+ch->firsts[CHET_DT],data)) {
380 			VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
381 				elem+ch->firsts[CHET_DT]);
382 		} else {
383 			VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
384 			if (data[6] & 0x80) {
385 				VPRINTK(KERN_CONT, "not this SCSI bus\n");
386 				ch->dt[elem] = NULL;
387 			} else if (0 == (data[6] & 0x30)) {
388 				VPRINTK(KERN_CONT, "ID/LUN unknown\n");
389 				ch->dt[elem] = NULL;
390 			} else {
391 				id  = ch->device->id;
392 				lun = 0;
393 				if (data[6] & 0x20) id  = data[7];
394 				if (data[6] & 0x10) lun = data[6] & 7;
395 			}
396 		}
397 		if (-1 != id) {
398 			VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
399 			ch->dt[elem] =
400 				scsi_device_lookup(ch->device->host,
401 						   ch->device->channel,
402 						   id,lun);
403 			if (!ch->dt[elem]) {
404 				/* should not happen */
405 				VPRINTK(KERN_CONT, "Huh? device not found!\n");
406 			} else {
407 				VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
408 					ch->dt[elem]->vendor,
409 					ch->dt[elem]->model,
410 					ch->dt[elem]->rev);
411 			}
412 		}
413 	}
414 	ch->voltags = 1;
415 	kfree(buffer);
416 
417 	return 0;
418 }
419 
420 /* ------------------------------------------------------------------------ */
421 
422 static int
423 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
424 {
425 	u_char  cmd[10];
426 
427 	DPRINTK("position: 0x%x\n",elem);
428 	if (0 == trans)
429 		trans = ch->firsts[CHET_MT];
430 	memset(cmd,0,sizeof(cmd));
431 	cmd[0]  = POSITION_TO_ELEMENT;
432 	cmd[1]  = (ch->device->lun & 0x7) << 5;
433 	cmd[2]  = (trans >> 8) & 0xff;
434 	cmd[3]  =  trans       & 0xff;
435 	cmd[4]  = (elem  >> 8) & 0xff;
436 	cmd[5]  =  elem        & 0xff;
437 	cmd[8]  = rotate ? 1 : 0;
438 	return ch_do_scsi(ch, cmd, 10, NULL, 0, REQ_OP_DRV_IN);
439 }
440 
441 static int
442 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
443 {
444 	u_char  cmd[12];
445 
446 	DPRINTK("move: 0x%x => 0x%x\n",src,dest);
447 	if (0 == trans)
448 		trans = ch->firsts[CHET_MT];
449 	memset(cmd,0,sizeof(cmd));
450 	cmd[0]  = MOVE_MEDIUM;
451 	cmd[1]  = (ch->device->lun & 0x7) << 5;
452 	cmd[2]  = (trans >> 8) & 0xff;
453 	cmd[3]  =  trans       & 0xff;
454 	cmd[4]  = (src   >> 8) & 0xff;
455 	cmd[5]  =  src         & 0xff;
456 	cmd[6]  = (dest  >> 8) & 0xff;
457 	cmd[7]  =  dest        & 0xff;
458 	cmd[10] = rotate ? 1 : 0;
459 	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
460 }
461 
462 static int
463 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
464 	    u_int dest1, u_int dest2, int rotate1, int rotate2)
465 {
466 	u_char  cmd[12];
467 
468 	DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
469 		src,dest1,dest2);
470 	if (0 == trans)
471 		trans = ch->firsts[CHET_MT];
472 	memset(cmd,0,sizeof(cmd));
473 	cmd[0]  = EXCHANGE_MEDIUM;
474 	cmd[1]  = (ch->device->lun & 0x7) << 5;
475 	cmd[2]  = (trans >> 8) & 0xff;
476 	cmd[3]  =  trans       & 0xff;
477 	cmd[4]  = (src   >> 8) & 0xff;
478 	cmd[5]  =  src         & 0xff;
479 	cmd[6]  = (dest1 >> 8) & 0xff;
480 	cmd[7]  =  dest1       & 0xff;
481 	cmd[8]  = (dest2 >> 8) & 0xff;
482 	cmd[9]  =  dest2       & 0xff;
483 	cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
484 
485 	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
486 }
487 
488 static void
489 ch_check_voltag(char *tag)
490 {
491 	int i;
492 
493 	for (i = 0; i < 32; i++) {
494 		/* restrict to ascii */
495 		if (tag[i] >= 0x7f || tag[i] < 0x20)
496 			tag[i] = ' ';
497 		/* don't allow search wildcards */
498 		if (tag[i] == '?' ||
499 		    tag[i] == '*')
500 			tag[i] = ' ';
501 	}
502 }
503 
504 static int
505 ch_set_voltag(scsi_changer *ch, u_int elem,
506 	      int alternate, int clear, u_char *tag)
507 {
508 	u_char  cmd[12];
509 	u_char  *buffer;
510 	int result;
511 
512 	buffer = kzalloc(512, GFP_KERNEL);
513 	if (!buffer)
514 		return -ENOMEM;
515 
516 	DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
517 		clear     ? "clear"     : "set",
518 		alternate ? "alternate" : "primary",
519 		elem, tag);
520 	memset(cmd,0,sizeof(cmd));
521 	cmd[0]  = SEND_VOLUME_TAG;
522 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
523 		ch_elem_to_typecode(ch,elem);
524 	cmd[2] = (elem >> 8) & 0xff;
525 	cmd[3] = elem        & 0xff;
526 	cmd[5] = clear
527 		? (alternate ? 0x0d : 0x0c)
528 		: (alternate ? 0x0b : 0x0a);
529 
530 	cmd[9] = 255;
531 
532 	memcpy(buffer,tag,32);
533 	ch_check_voltag(buffer);
534 
535 	result = ch_do_scsi(ch, cmd, 12, buffer, 256, REQ_OP_DRV_OUT);
536 	kfree(buffer);
537 	return result;
538 }
539 
540 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
541 {
542 	int retval = 0;
543 	u_char data[16];
544 	unsigned int i;
545 
546 	mutex_lock(&ch->lock);
547 	for (i = 0; i < ch->counts[type]; i++) {
548 		if (0 != ch_read_element_status
549 		    (ch, ch->firsts[type]+i,data)) {
550 			retval = -EIO;
551 			break;
552 		}
553 		put_user(data[2], dest+i);
554 		if (data[2] & CESTATUS_EXCEPT)
555 			VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
556 				ch->firsts[type]+i,
557 				(int)data[4],(int)data[5]);
558 		retval = ch_read_element_status
559 			(ch, ch->firsts[type]+i,data);
560 		if (0 != retval)
561 			break;
562 	}
563 	mutex_unlock(&ch->lock);
564 	return retval;
565 }
566 
567 /* ------------------------------------------------------------------------ */
568 
569 static void ch_destroy(struct kref *ref)
570 {
571 	scsi_changer *ch = container_of(ref, scsi_changer, ref);
572 
573 	ch->device = NULL;
574 	kfree(ch->dt);
575 	kfree(ch);
576 }
577 
578 static int
579 ch_release(struct inode *inode, struct file *file)
580 {
581 	scsi_changer *ch = file->private_data;
582 
583 	scsi_device_put(ch->device);
584 	file->private_data = NULL;
585 	kref_put(&ch->ref, ch_destroy);
586 	return 0;
587 }
588 
589 static int
590 ch_open(struct inode *inode, struct file *file)
591 {
592 	scsi_changer *ch;
593 	int minor = iminor(inode);
594 
595 	spin_lock(&ch_index_lock);
596 	ch = idr_find(&ch_index_idr, minor);
597 
598 	if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
599 		spin_unlock(&ch_index_lock);
600 		return -ENXIO;
601 	}
602 	spin_unlock(&ch_index_lock);
603 	if (scsi_device_get(ch->device)) {
604 		kref_put(&ch->ref, ch_destroy);
605 		return -ENXIO;
606 	}
607 	/* Synchronize with ch_probe() */
608 	mutex_lock(&ch->lock);
609 	file->private_data = ch;
610 	mutex_unlock(&ch->lock);
611 	return 0;
612 }
613 
614 static int
615 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
616 {
617 	if (type >= CH_TYPES  ||  unit >= ch->counts[type])
618 		return -1;
619 	return 0;
620 }
621 
622 struct changer_element_status32 {
623 	int		ces_type;
624 	compat_uptr_t	ces_data;
625 };
626 #define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
627 
628 static long ch_ioctl(struct file *file,
629 		    unsigned int cmd, unsigned long arg)
630 {
631 	scsi_changer *ch = file->private_data;
632 	int retval;
633 	void __user *argp = (void __user *)arg;
634 
635 	retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
636 			file->f_flags & O_NDELAY);
637 	if (retval)
638 		return retval;
639 
640 	switch (cmd) {
641 	case CHIOGPARAMS:
642 	{
643 		struct changer_params params;
644 
645 		params.cp_curpicker = 0;
646 		params.cp_npickers  = ch->counts[CHET_MT];
647 		params.cp_nslots    = ch->counts[CHET_ST];
648 		params.cp_nportals  = ch->counts[CHET_IE];
649 		params.cp_ndrives   = ch->counts[CHET_DT];
650 
651 		if (copy_to_user(argp, &params, sizeof(params)))
652 			return -EFAULT;
653 		return 0;
654 	}
655 	case CHIOGVPARAMS:
656 	{
657 		struct changer_vendor_params vparams;
658 
659 		memset(&vparams,0,sizeof(vparams));
660 		if (ch->counts[CHET_V1]) {
661 			vparams.cvp_n1  = ch->counts[CHET_V1];
662 			strscpy(vparams.cvp_label1, vendor_labels[0],
663 				sizeof(vparams.cvp_label1));
664 		}
665 		if (ch->counts[CHET_V2]) {
666 			vparams.cvp_n2  = ch->counts[CHET_V2];
667 			strscpy(vparams.cvp_label2, vendor_labels[1],
668 				sizeof(vparams.cvp_label2));
669 		}
670 		if (ch->counts[CHET_V3]) {
671 			vparams.cvp_n3  = ch->counts[CHET_V3];
672 			strscpy(vparams.cvp_label3, vendor_labels[2],
673 				sizeof(vparams.cvp_label3));
674 		}
675 		if (ch->counts[CHET_V4]) {
676 			vparams.cvp_n4  = ch->counts[CHET_V4];
677 			strscpy(vparams.cvp_label4, vendor_labels[3],
678 				sizeof(vparams.cvp_label4));
679 		}
680 		if (copy_to_user(argp, &vparams, sizeof(vparams)))
681 			return -EFAULT;
682 		return 0;
683 	}
684 
685 	case CHIOPOSITION:
686 	{
687 		struct changer_position pos;
688 
689 		if (copy_from_user(&pos, argp, sizeof (pos)))
690 			return -EFAULT;
691 
692 		if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
693 			DPRINTK("CHIOPOSITION: invalid parameter\n");
694 			return -EBADSLT;
695 		}
696 		mutex_lock(&ch->lock);
697 		retval = ch_position(ch,0,
698 				     ch->firsts[pos.cp_type] + pos.cp_unit,
699 				     pos.cp_flags & CP_INVERT);
700 		mutex_unlock(&ch->lock);
701 		return retval;
702 	}
703 
704 	case CHIOMOVE:
705 	{
706 		struct changer_move mv;
707 
708 		if (copy_from_user(&mv, argp, sizeof (mv)))
709 			return -EFAULT;
710 
711 		if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
712 		    0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
713 			DPRINTK("CHIOMOVE: invalid parameter\n");
714 			return -EBADSLT;
715 		}
716 
717 		mutex_lock(&ch->lock);
718 		retval = ch_move(ch,0,
719 				 ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
720 				 ch->firsts[mv.cm_totype]   + mv.cm_tounit,
721 				 mv.cm_flags & CM_INVERT);
722 		mutex_unlock(&ch->lock);
723 		return retval;
724 	}
725 
726 	case CHIOEXCHANGE:
727 	{
728 		struct changer_exchange mv;
729 
730 		if (copy_from_user(&mv, argp, sizeof (mv)))
731 			return -EFAULT;
732 
733 		if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
734 		    0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
735 		    0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
736 			DPRINTK("CHIOEXCHANGE: invalid parameter\n");
737 			return -EBADSLT;
738 		}
739 
740 		mutex_lock(&ch->lock);
741 		retval = ch_exchange
742 			(ch,0,
743 			 ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
744 			 ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
745 			 ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
746 			 mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
747 		mutex_unlock(&ch->lock);
748 		return retval;
749 	}
750 
751 	case CHIOGSTATUS:
752 	{
753 		struct changer_element_status ces;
754 
755 		if (copy_from_user(&ces, argp, sizeof (ces)))
756 			return -EFAULT;
757 		if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
758 			return -EINVAL;
759 
760 		return ch_gstatus(ch, ces.ces_type, ces.ces_data);
761 	}
762 #ifdef CONFIG_COMPAT
763 	case CHIOGSTATUS32:
764 	{
765 		struct changer_element_status32 ces32;
766 
767 		if (copy_from_user(&ces32, argp, sizeof(ces32)))
768 			return -EFAULT;
769 		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
770 			return -EINVAL;
771 
772 		return ch_gstatus(ch, ces32.ces_type,
773 				  compat_ptr(ces32.ces_data));
774 	}
775 #endif
776 	case CHIOGELEM:
777 	{
778 		struct changer_get_element cge;
779 		u_char ch_cmd[12];
780 		u_char *buffer;
781 		unsigned int elem;
782 		int     result,i;
783 
784 		if (copy_from_user(&cge, argp, sizeof (cge)))
785 			return -EFAULT;
786 
787 		if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
788 			return -EINVAL;
789 		elem = ch->firsts[cge.cge_type] + cge.cge_unit;
790 
791 		buffer = kmalloc(512, GFP_KERNEL);
792 		if (!buffer)
793 			return -ENOMEM;
794 		mutex_lock(&ch->lock);
795 
796 	voltag_retry:
797 		memset(ch_cmd, 0, sizeof(ch_cmd));
798 		ch_cmd[0] = READ_ELEMENT_STATUS;
799 		ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
800 			(ch->voltags ? 0x10 : 0) |
801 			ch_elem_to_typecode(ch,elem);
802 		ch_cmd[2] = (elem >> 8) & 0xff;
803 		ch_cmd[3] = elem        & 0xff;
804 		ch_cmd[5] = 1;
805 		ch_cmd[9] = 255;
806 
807 		result = ch_do_scsi(ch, ch_cmd, 12, buffer, 256, REQ_OP_DRV_IN);
808 		if (!result) {
809 			cge.cge_status = buffer[18];
810 			cge.cge_flags = 0;
811 			if (buffer[18] & CESTATUS_EXCEPT) {
812 				cge.cge_errno = EIO;
813 			}
814 			if (buffer[25] & 0x80) {
815 				cge.cge_flags |= CGE_SRC;
816 				if (buffer[25] & 0x40)
817 					cge.cge_flags |= CGE_INVERT;
818 				elem = (buffer[26]<<8) | buffer[27];
819 				for (i = 0; i < 4; i++) {
820 					if (elem >= ch->firsts[i] &&
821 					    elem <  ch->firsts[i] + ch->counts[i]) {
822 						cge.cge_srctype = i;
823 						cge.cge_srcunit = elem-ch->firsts[i];
824 					}
825 				}
826 			}
827 			if ((buffer[22] & 0x30) == 0x30) {
828 				cge.cge_flags |= CGE_IDLUN;
829 				cge.cge_id  = buffer[23];
830 				cge.cge_lun = buffer[22] & 7;
831 			}
832 			if (buffer[9] & 0x80) {
833 				cge.cge_flags |= CGE_PVOLTAG;
834 				memcpy(cge.cge_pvoltag,buffer+28,36);
835 			}
836 			if (buffer[9] & 0x40) {
837 				cge.cge_flags |= CGE_AVOLTAG;
838 				memcpy(cge.cge_avoltag,buffer+64,36);
839 			}
840 		} else if (ch->voltags) {
841 			ch->voltags = 0;
842 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
843 			goto voltag_retry;
844 		}
845 		kfree(buffer);
846 		mutex_unlock(&ch->lock);
847 
848 		if (copy_to_user(argp, &cge, sizeof (cge)))
849 			return -EFAULT;
850 		return result;
851 	}
852 
853 	case CHIOINITELEM:
854 	{
855 		mutex_lock(&ch->lock);
856 		retval = ch_init_elem(ch);
857 		mutex_unlock(&ch->lock);
858 		return retval;
859 	}
860 
861 	case CHIOSVOLTAG:
862 	{
863 		struct changer_set_voltag csv;
864 		int elem;
865 
866 		if (copy_from_user(&csv, argp, sizeof(csv)))
867 			return -EFAULT;
868 
869 		if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
870 			DPRINTK("CHIOSVOLTAG: invalid parameter\n");
871 			return -EBADSLT;
872 		}
873 		elem = ch->firsts[csv.csv_type] + csv.csv_unit;
874 		mutex_lock(&ch->lock);
875 		retval = ch_set_voltag(ch, elem,
876 				       csv.csv_flags & CSV_AVOLTAG,
877 				       csv.csv_flags & CSV_CLEARTAG,
878 				       csv.csv_voltag);
879 		mutex_unlock(&ch->lock);
880 		return retval;
881 	}
882 
883 	default:
884 		return scsi_ioctl(ch->device, file->f_mode & FMODE_WRITE, cmd,
885 				  argp);
886 
887 	}
888 }
889 
890 /* ------------------------------------------------------------------------ */
891 
892 static int ch_probe(struct device *dev)
893 {
894 	struct scsi_device *sd = to_scsi_device(dev);
895 	struct device *class_dev;
896 	int ret;
897 	scsi_changer *ch;
898 
899 	if (sd->type != TYPE_MEDIUM_CHANGER)
900 		return -ENODEV;
901 
902 	ch = kzalloc(sizeof(*ch), GFP_KERNEL);
903 	if (NULL == ch)
904 		return -ENOMEM;
905 
906 	idr_preload(GFP_KERNEL);
907 	spin_lock(&ch_index_lock);
908 	ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
909 	spin_unlock(&ch_index_lock);
910 	idr_preload_end();
911 
912 	if (ret < 0) {
913 		if (ret == -ENOSPC)
914 			ret = -ENODEV;
915 		goto free_ch;
916 	}
917 
918 	ch->minor = ret;
919 	sprintf(ch->name,"ch%d",ch->minor);
920 	ret = scsi_device_get(sd);
921 	if (ret) {
922 		sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
923 			    ch->minor);
924 		goto remove_idr;
925 	}
926 
927 	mutex_init(&ch->lock);
928 	kref_init(&ch->ref);
929 	ch->device = sd;
930 	class_dev = device_create(ch_sysfs_class, dev,
931 				  MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
932 				  "s%s", ch->name);
933 	if (IS_ERR(class_dev)) {
934 		sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
935 			    ch->minor);
936 		ret = PTR_ERR(class_dev);
937 		goto put_device;
938 	}
939 
940 	mutex_lock(&ch->lock);
941 	ret = ch_readconfig(ch);
942 	if (ret) {
943 		mutex_unlock(&ch->lock);
944 		goto destroy_dev;
945 	}
946 	if (init)
947 		ch_init_elem(ch);
948 
949 	mutex_unlock(&ch->lock);
950 	dev_set_drvdata(dev, ch);
951 	sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
952 
953 	return 0;
954 destroy_dev:
955 	device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
956 put_device:
957 	scsi_device_put(sd);
958 remove_idr:
959 	idr_remove(&ch_index_idr, ch->minor);
960 free_ch:
961 	kfree(ch);
962 	return ret;
963 }
964 
965 static int ch_remove(struct device *dev)
966 {
967 	scsi_changer *ch = dev_get_drvdata(dev);
968 
969 	spin_lock(&ch_index_lock);
970 	idr_remove(&ch_index_idr, ch->minor);
971 	dev_set_drvdata(dev, NULL);
972 	spin_unlock(&ch_index_lock);
973 
974 	device_destroy(ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR,ch->minor));
975 	scsi_device_put(ch->device);
976 	kref_put(&ch->ref, ch_destroy);
977 	return 0;
978 }
979 
980 static struct scsi_driver ch_template = {
981 	.gendrv     	= {
982 		.name	= "ch",
983 		.owner	= THIS_MODULE,
984 		.probe  = ch_probe,
985 		.remove = ch_remove,
986 	},
987 };
988 
989 static const struct file_operations changer_fops = {
990 	.owner		= THIS_MODULE,
991 	.open		= ch_open,
992 	.release	= ch_release,
993 	.unlocked_ioctl	= ch_ioctl,
994 	.compat_ioctl	= compat_ptr_ioctl,
995 	.llseek		= noop_llseek,
996 };
997 
998 static int __init init_ch_module(void)
999 {
1000 	int rc;
1001 
1002 	printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
1003         ch_sysfs_class = class_create("scsi_changer");
1004         if (IS_ERR(ch_sysfs_class)) {
1005 		rc = PTR_ERR(ch_sysfs_class);
1006 		return rc;
1007         }
1008 	rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1009 	if (rc < 0) {
1010 		printk("Unable to get major %d for SCSI-Changer\n",
1011 		       SCSI_CHANGER_MAJOR);
1012 		goto fail1;
1013 	}
1014 	rc = scsi_register_driver(&ch_template.gendrv);
1015 	if (rc < 0)
1016 		goto fail2;
1017 	return 0;
1018 
1019  fail2:
1020 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1021  fail1:
1022 	class_destroy(ch_sysfs_class);
1023 	return rc;
1024 }
1025 
1026 static void __exit exit_ch_module(void)
1027 {
1028 	scsi_unregister_driver(&ch_template.gendrv);
1029 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1030 	class_destroy(ch_sysfs_class);
1031 	idr_destroy(&ch_index_idr);
1032 }
1033 
1034 module_init(init_ch_module);
1035 module_exit(exit_ch_module);
1036