xref: /linux/drivers/scsi/ch.c (revision 69050f8d6d075dc01af7a5f2f550a8067510366f)
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 	struct scsi_device  **dt;        /* ptrs to data transfer elements */
116 	u_int               firsts[CH_TYPES];
117 	u_int               counts[CH_TYPES];
118 	u_int		    voltags;
119 	struct mutex	    lock;
120 } scsi_changer;
121 
122 static DEFINE_IDR(ch_index_idr);
123 static DEFINE_SPINLOCK(ch_index_lock);
124 
125 static const struct {
126 	unsigned char  sense;
127 	unsigned char  asc;
128 	unsigned char  ascq;
129 	int	       errno;
130 } ch_err[] = {
131 /* Just filled in what looks right. Hav'nt checked any standard paper for
132    these errno assignments, so they may be wrong... */
133 	{
134 		.sense  = ILLEGAL_REQUEST,
135 		.asc    = 0x21,
136 		.ascq   = 0x01,
137 		.errno  = EBADSLT, /* Invalid element address */
138 	},{
139 		.sense  = ILLEGAL_REQUEST,
140 		.asc    = 0x28,
141 		.ascq   = 0x01,
142 		.errno  = EBADE,   /* Import or export element accessed */
143 	},{
144 		.sense  = ILLEGAL_REQUEST,
145 		.asc    = 0x3B,
146 		.ascq   = 0x0D,
147 		.errno  = EXFULL,  /* Medium destination element full */
148 	},{
149 		.sense  = ILLEGAL_REQUEST,
150 		.asc    = 0x3B,
151 		.ascq   = 0x0E,
152 		.errno  = EBADE,   /* Medium source element empty */
153 	},{
154 		.sense  = ILLEGAL_REQUEST,
155 		.asc    = 0x20,
156 		.ascq   = 0x00,
157 		.errno  = EBADRQC, /* Invalid command operation code */
158 	},{
159 	        /* end of list */
160 	}
161 };
162 
163 /* ------------------------------------------------------------------- */
164 
165 static int ch_find_errno(struct scsi_sense_hdr *sshdr)
166 {
167 	int i,errno = 0;
168 
169 	/* Check to see if additional sense information is available */
170 	if (scsi_sense_valid(sshdr) &&
171 	    sshdr->asc != 0) {
172 		for (i = 0; ch_err[i].errno != 0; i++) {
173 			if (ch_err[i].sense == sshdr->sense_key &&
174 			    ch_err[i].asc   == sshdr->asc &&
175 			    ch_err[i].ascq  == sshdr->ascq) {
176 				errno = -ch_err[i].errno;
177 				break;
178 			}
179 		}
180 	}
181 	if (errno == 0)
182 		errno = -EIO;
183 	return errno;
184 }
185 
186 static int
187 ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
188 	   void *buffer, unsigned int buflength, enum req_op op)
189 {
190 	int errno = 0, timeout, result;
191 	struct scsi_sense_hdr sshdr;
192 	struct scsi_failure failure_defs[] = {
193 		{
194 			.sense = UNIT_ATTENTION,
195 			.asc = SCMD_FAILURE_ASC_ANY,
196 			.ascq = SCMD_FAILURE_ASCQ_ANY,
197 			.allowed = 3,
198 			.result = SAM_STAT_CHECK_CONDITION,
199 		},
200 		{}
201 	};
202 	struct scsi_failures failures = {
203 		.failure_definitions = failure_defs,
204 	};
205 	const struct scsi_exec_args exec_args = {
206 		.sshdr = &sshdr,
207 		.failures = &failures,
208 	};
209 
210 	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
211 		? timeout_init : timeout_move;
212 
213 	result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
214 				  timeout * HZ, MAX_RETRIES, &exec_args);
215 	if (result < 0)
216 		return result;
217 	if (scsi_sense_valid(&sshdr)) {
218 		if (debug)
219 			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
220 		errno = ch_find_errno(&sshdr);
221 	}
222 	return errno;
223 }
224 
225 /* ------------------------------------------------------------------------ */
226 
227 static int
228 ch_elem_to_typecode(scsi_changer *ch, u_int elem)
229 {
230 	int i;
231 
232 	for (i = 0; i < CH_TYPES; i++) {
233 		if (elem >= ch->firsts[i]  &&
234 		    elem <  ch->firsts[i] +
235 	            ch->counts[i])
236 			return i+1;
237 	}
238 	return 0;
239 }
240 
241 static int
242 ch_read_element_status(scsi_changer *ch, u_int elem, char *data)
243 {
244 	u_char  cmd[12];
245 	u_char  *buffer;
246 	int     result;
247 
248 	buffer = kmalloc(512, GFP_KERNEL);
249 	if(!buffer)
250 		return -ENOMEM;
251 
252  retry:
253 	memset(cmd,0,sizeof(cmd));
254 	cmd[0] = READ_ELEMENT_STATUS;
255 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
256 		(ch->voltags ? 0x10 : 0) |
257 		ch_elem_to_typecode(ch,elem);
258 	cmd[2] = (elem >> 8) & 0xff;
259 	cmd[3] = elem        & 0xff;
260 	cmd[5] = 1;
261 	cmd[9] = 255;
262 	if (0 == (result = ch_do_scsi(ch, cmd, 12,
263 				      buffer, 256, REQ_OP_DRV_IN))) {
264 		if (((buffer[16] << 8) | buffer[17]) != elem) {
265 			DPRINTK("asked for element 0x%02x, got 0x%02x\n",
266 				elem,(buffer[16] << 8) | buffer[17]);
267 			kfree(buffer);
268 			return -EIO;
269 		}
270 		memcpy(data,buffer+16,16);
271 	} else {
272 		if (ch->voltags) {
273 			ch->voltags = 0;
274 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
275 			goto retry;
276 		}
277 		DPRINTK("READ ELEMENT STATUS for element 0x%x failed\n",elem);
278 	}
279 	kfree(buffer);
280 	return result;
281 }
282 
283 static int
284 ch_init_elem(scsi_changer *ch)
285 {
286 	int err;
287 	u_char cmd[6];
288 
289 	VPRINTK(KERN_INFO, "INITIALIZE ELEMENT STATUS, may take some time ...\n");
290 	memset(cmd,0,sizeof(cmd));
291 	cmd[0] = INITIALIZE_ELEMENT_STATUS;
292 	cmd[1] = (ch->device->lun & 0x7) << 5;
293 	err = ch_do_scsi(ch, cmd, 6, NULL, 0, REQ_OP_DRV_IN);
294 	VPRINTK(KERN_INFO, "... finished\n");
295 	return err;
296 }
297 
298 static int
299 ch_readconfig(scsi_changer *ch)
300 {
301 	u_char  cmd[10], data[16];
302 	u_char  *buffer;
303 	int     result,id,lun,i;
304 	u_int   elem;
305 
306 	buffer = kzalloc(512, GFP_KERNEL);
307 	if (!buffer)
308 		return -ENOMEM;
309 
310 	memset(cmd,0,sizeof(cmd));
311 	cmd[0] = MODE_SENSE;
312 	cmd[1] = (ch->device->lun & 0x7) << 5;
313 	cmd[2] = 0x1d;
314 	cmd[4] = 255;
315 	result = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
316 	if (0 != result) {
317 		cmd[1] |= (1<<3);
318 		result  = ch_do_scsi(ch, cmd, 10, buffer, 255, REQ_OP_DRV_IN);
319 	}
320 	if (0 == result) {
321 		ch->firsts[CHET_MT] =
322 			(buffer[buffer[3]+ 6] << 8) | buffer[buffer[3]+ 7];
323 		ch->counts[CHET_MT] =
324 			(buffer[buffer[3]+ 8] << 8) | buffer[buffer[3]+ 9];
325 		ch->firsts[CHET_ST] =
326 			(buffer[buffer[3]+10] << 8) | buffer[buffer[3]+11];
327 		ch->counts[CHET_ST] =
328 			(buffer[buffer[3]+12] << 8) | buffer[buffer[3]+13];
329 		ch->firsts[CHET_IE] =
330 			(buffer[buffer[3]+14] << 8) | buffer[buffer[3]+15];
331 		ch->counts[CHET_IE] =
332 			(buffer[buffer[3]+16] << 8) | buffer[buffer[3]+17];
333 		ch->firsts[CHET_DT] =
334 			(buffer[buffer[3]+18] << 8) | buffer[buffer[3]+19];
335 		ch->counts[CHET_DT] =
336 			(buffer[buffer[3]+20] << 8) | buffer[buffer[3]+21];
337 		VPRINTK(KERN_INFO, "type #1 (mt): 0x%x+%d [medium transport]\n",
338 			ch->firsts[CHET_MT],
339 			ch->counts[CHET_MT]);
340 		VPRINTK(KERN_INFO, "type #2 (st): 0x%x+%d [storage]\n",
341 			ch->firsts[CHET_ST],
342 			ch->counts[CHET_ST]);
343 		VPRINTK(KERN_INFO, "type #3 (ie): 0x%x+%d [import/export]\n",
344 			ch->firsts[CHET_IE],
345 			ch->counts[CHET_IE]);
346 		VPRINTK(KERN_INFO, "type #4 (dt): 0x%x+%d [data transfer]\n",
347 			ch->firsts[CHET_DT],
348 			ch->counts[CHET_DT]);
349 	} else {
350 		VPRINTK(KERN_INFO, "reading element address assignment page failed!\n");
351 	}
352 
353 	/* vendor specific element types */
354 	for (i = 0; i < 4; i++) {
355 		if (0 == vendor_counts[i])
356 			continue;
357 		if (NULL == vendor_labels[i])
358 			continue;
359 		ch->firsts[CHET_V1+i] = vendor_firsts[i];
360 		ch->counts[CHET_V1+i] = vendor_counts[i];
361 		VPRINTK(KERN_INFO, "type #%d (v%d): 0x%x+%d [%s, vendor specific]\n",
362 			i+5,i+1,vendor_firsts[i],vendor_counts[i],
363 			vendor_labels[i]);
364 	}
365 
366 	/* look up the devices of the data transfer elements */
367 	ch->dt = kzalloc_objs(*ch->dt, ch->counts[CHET_DT], GFP_KERNEL);
368 
369 	if (!ch->dt) {
370 		kfree(buffer);
371 		return -ENOMEM;
372 	}
373 
374 	for (elem = 0; elem < ch->counts[CHET_DT]; elem++) {
375 		id  = -1;
376 		lun = 0;
377 		if (elem < CH_DT_MAX  &&  -1 != dt_id[elem]) {
378 			id  = dt_id[elem];
379 			lun = dt_lun[elem];
380 			VPRINTK(KERN_INFO, "dt 0x%x: [insmod option] ",
381 				elem+ch->firsts[CHET_DT]);
382 		} else if (0 != ch_read_element_status
383 			   (ch,elem+ch->firsts[CHET_DT],data)) {
384 			VPRINTK(KERN_INFO, "dt 0x%x: READ ELEMENT STATUS failed\n",
385 				elem+ch->firsts[CHET_DT]);
386 		} else {
387 			VPRINTK(KERN_INFO, "dt 0x%x: ",elem+ch->firsts[CHET_DT]);
388 			if (data[6] & 0x80) {
389 				VPRINTK(KERN_CONT, "not this SCSI bus\n");
390 				ch->dt[elem] = NULL;
391 			} else if (0 == (data[6] & 0x30)) {
392 				VPRINTK(KERN_CONT, "ID/LUN unknown\n");
393 				ch->dt[elem] = NULL;
394 			} else {
395 				id  = ch->device->id;
396 				lun = 0;
397 				if (data[6] & 0x20) id  = data[7];
398 				if (data[6] & 0x10) lun = data[6] & 7;
399 			}
400 		}
401 		if (-1 != id) {
402 			VPRINTK(KERN_CONT, "ID %i, LUN %i, ",id,lun);
403 			ch->dt[elem] =
404 				scsi_device_lookup(ch->device->host,
405 						   ch->device->channel,
406 						   id,lun);
407 			if (!ch->dt[elem]) {
408 				/* should not happen */
409 				VPRINTK(KERN_CONT, "Huh? device not found!\n");
410 			} else {
411 				VPRINTK(KERN_CONT, "name: %8.8s %16.16s %4.4s\n",
412 					ch->dt[elem]->vendor,
413 					ch->dt[elem]->model,
414 					ch->dt[elem]->rev);
415 			}
416 		}
417 	}
418 	ch->voltags = 1;
419 	kfree(buffer);
420 
421 	return 0;
422 }
423 
424 /* ------------------------------------------------------------------------ */
425 
426 static int
427 ch_position(scsi_changer *ch, u_int trans, u_int elem, int rotate)
428 {
429 	u_char  cmd[10];
430 
431 	DPRINTK("position: 0x%x\n",elem);
432 	if (0 == trans)
433 		trans = ch->firsts[CHET_MT];
434 	memset(cmd,0,sizeof(cmd));
435 	cmd[0]  = POSITION_TO_ELEMENT;
436 	cmd[1]  = (ch->device->lun & 0x7) << 5;
437 	cmd[2]  = (trans >> 8) & 0xff;
438 	cmd[3]  =  trans       & 0xff;
439 	cmd[4]  = (elem  >> 8) & 0xff;
440 	cmd[5]  =  elem        & 0xff;
441 	cmd[8]  = rotate ? 1 : 0;
442 	return ch_do_scsi(ch, cmd, 10, NULL, 0, REQ_OP_DRV_IN);
443 }
444 
445 static int
446 ch_move(scsi_changer *ch, u_int trans, u_int src, u_int dest, int rotate)
447 {
448 	u_char  cmd[12];
449 
450 	DPRINTK("move: 0x%x => 0x%x\n",src,dest);
451 	if (0 == trans)
452 		trans = ch->firsts[CHET_MT];
453 	memset(cmd,0,sizeof(cmd));
454 	cmd[0]  = MOVE_MEDIUM;
455 	cmd[1]  = (ch->device->lun & 0x7) << 5;
456 	cmd[2]  = (trans >> 8) & 0xff;
457 	cmd[3]  =  trans       & 0xff;
458 	cmd[4]  = (src   >> 8) & 0xff;
459 	cmd[5]  =  src         & 0xff;
460 	cmd[6]  = (dest  >> 8) & 0xff;
461 	cmd[7]  =  dest        & 0xff;
462 	cmd[10] = rotate ? 1 : 0;
463 	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
464 }
465 
466 static int
467 ch_exchange(scsi_changer *ch, u_int trans, u_int src,
468 	    u_int dest1, u_int dest2, int rotate1, int rotate2)
469 {
470 	u_char  cmd[12];
471 
472 	DPRINTK("exchange: 0x%x => 0x%x => 0x%x\n",
473 		src,dest1,dest2);
474 	if (0 == trans)
475 		trans = ch->firsts[CHET_MT];
476 	memset(cmd,0,sizeof(cmd));
477 	cmd[0]  = EXCHANGE_MEDIUM;
478 	cmd[1]  = (ch->device->lun & 0x7) << 5;
479 	cmd[2]  = (trans >> 8) & 0xff;
480 	cmd[3]  =  trans       & 0xff;
481 	cmd[4]  = (src   >> 8) & 0xff;
482 	cmd[5]  =  src         & 0xff;
483 	cmd[6]  = (dest1 >> 8) & 0xff;
484 	cmd[7]  =  dest1       & 0xff;
485 	cmd[8]  = (dest2 >> 8) & 0xff;
486 	cmd[9]  =  dest2       & 0xff;
487 	cmd[10] = (rotate1 ? 1 : 0) | (rotate2 ? 2 : 0);
488 
489 	return ch_do_scsi(ch, cmd, 12, NULL, 0, REQ_OP_DRV_IN);
490 }
491 
492 static void
493 ch_check_voltag(char *tag)
494 {
495 	int i;
496 
497 	for (i = 0; i < 32; i++) {
498 		/* restrict to ascii */
499 		if (tag[i] >= 0x7f || tag[i] < 0x20)
500 			tag[i] = ' ';
501 		/* don't allow search wildcards */
502 		if (tag[i] == '?' ||
503 		    tag[i] == '*')
504 			tag[i] = ' ';
505 	}
506 }
507 
508 static int
509 ch_set_voltag(scsi_changer *ch, u_int elem,
510 	      int alternate, int clear, u_char *tag)
511 {
512 	u_char  cmd[12];
513 	u_char  *buffer;
514 	int result;
515 
516 	buffer = kzalloc(512, GFP_KERNEL);
517 	if (!buffer)
518 		return -ENOMEM;
519 
520 	DPRINTK("%s %s voltag: 0x%x => \"%s\"\n",
521 		clear     ? "clear"     : "set",
522 		alternate ? "alternate" : "primary",
523 		elem, tag);
524 	memset(cmd,0,sizeof(cmd));
525 	cmd[0]  = SEND_VOLUME_TAG;
526 	cmd[1] = ((ch->device->lun & 0x7) << 5) |
527 		ch_elem_to_typecode(ch,elem);
528 	cmd[2] = (elem >> 8) & 0xff;
529 	cmd[3] = elem        & 0xff;
530 	cmd[5] = clear
531 		? (alternate ? 0x0d : 0x0c)
532 		: (alternate ? 0x0b : 0x0a);
533 
534 	cmd[9] = 255;
535 
536 	memcpy(buffer,tag,32);
537 	ch_check_voltag(buffer);
538 
539 	result = ch_do_scsi(ch, cmd, 12, buffer, 256, REQ_OP_DRV_OUT);
540 	kfree(buffer);
541 	return result;
542 }
543 
544 static int ch_gstatus(scsi_changer *ch, int type, unsigned char __user *dest)
545 {
546 	int retval = 0;
547 	u_char data[16];
548 	unsigned int i;
549 
550 	mutex_lock(&ch->lock);
551 	for (i = 0; i < ch->counts[type]; i++) {
552 		if (0 != ch_read_element_status
553 		    (ch, ch->firsts[type]+i,data)) {
554 			retval = -EIO;
555 			break;
556 		}
557 		put_user(data[2], dest+i);
558 		if (data[2] & CESTATUS_EXCEPT)
559 			VPRINTK(KERN_INFO, "element 0x%x: asc=0x%x, ascq=0x%x\n",
560 				ch->firsts[type]+i,
561 				(int)data[4],(int)data[5]);
562 		retval = ch_read_element_status
563 			(ch, ch->firsts[type]+i,data);
564 		if (0 != retval)
565 			break;
566 	}
567 	mutex_unlock(&ch->lock);
568 	return retval;
569 }
570 
571 /* ------------------------------------------------------------------------ */
572 
573 static void ch_destroy(struct kref *ref)
574 {
575 	scsi_changer *ch = container_of(ref, scsi_changer, ref);
576 
577 	ch->device = NULL;
578 	kfree(ch->dt);
579 	kfree(ch);
580 }
581 
582 static int
583 ch_release(struct inode *inode, struct file *file)
584 {
585 	scsi_changer *ch = file->private_data;
586 
587 	scsi_device_put(ch->device);
588 	file->private_data = NULL;
589 	kref_put(&ch->ref, ch_destroy);
590 	return 0;
591 }
592 
593 static int
594 ch_open(struct inode *inode, struct file *file)
595 {
596 	scsi_changer *ch;
597 	int minor = iminor(inode);
598 
599 	spin_lock(&ch_index_lock);
600 	ch = idr_find(&ch_index_idr, minor);
601 
602 	if (ch == NULL || !kref_get_unless_zero(&ch->ref)) {
603 		spin_unlock(&ch_index_lock);
604 		return -ENXIO;
605 	}
606 	spin_unlock(&ch_index_lock);
607 	if (scsi_device_get(ch->device)) {
608 		kref_put(&ch->ref, ch_destroy);
609 		return -ENXIO;
610 	}
611 	/* Synchronize with ch_probe() */
612 	mutex_lock(&ch->lock);
613 	file->private_data = ch;
614 	mutex_unlock(&ch->lock);
615 	return 0;
616 }
617 
618 static int
619 ch_checkrange(scsi_changer *ch, unsigned int type, unsigned int unit)
620 {
621 	if (type >= CH_TYPES  ||  unit >= ch->counts[type])
622 		return -1;
623 	return 0;
624 }
625 
626 struct changer_element_status32 {
627 	int		ces_type;
628 	compat_uptr_t	ces_data;
629 };
630 #define CHIOGSTATUS32  _IOW('c', 8, struct changer_element_status32)
631 
632 static long ch_ioctl(struct file *file,
633 		    unsigned int cmd, unsigned long arg)
634 {
635 	scsi_changer *ch = file->private_data;
636 	int retval;
637 	void __user *argp = (void __user *)arg;
638 
639 	retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
640 			file->f_flags & O_NDELAY);
641 	if (retval)
642 		return retval;
643 
644 	switch (cmd) {
645 	case CHIOGPARAMS:
646 	{
647 		struct changer_params params;
648 
649 		params.cp_curpicker = 0;
650 		params.cp_npickers  = ch->counts[CHET_MT];
651 		params.cp_nslots    = ch->counts[CHET_ST];
652 		params.cp_nportals  = ch->counts[CHET_IE];
653 		params.cp_ndrives   = ch->counts[CHET_DT];
654 
655 		if (copy_to_user(argp, &params, sizeof(params)))
656 			return -EFAULT;
657 		return 0;
658 	}
659 	case CHIOGVPARAMS:
660 	{
661 		struct changer_vendor_params vparams;
662 
663 		memset(&vparams,0,sizeof(vparams));
664 		if (ch->counts[CHET_V1]) {
665 			vparams.cvp_n1  = ch->counts[CHET_V1];
666 			strscpy(vparams.cvp_label1, vendor_labels[0],
667 				sizeof(vparams.cvp_label1));
668 		}
669 		if (ch->counts[CHET_V2]) {
670 			vparams.cvp_n2  = ch->counts[CHET_V2];
671 			strscpy(vparams.cvp_label2, vendor_labels[1],
672 				sizeof(vparams.cvp_label2));
673 		}
674 		if (ch->counts[CHET_V3]) {
675 			vparams.cvp_n3  = ch->counts[CHET_V3];
676 			strscpy(vparams.cvp_label3, vendor_labels[2],
677 				sizeof(vparams.cvp_label3));
678 		}
679 		if (ch->counts[CHET_V4]) {
680 			vparams.cvp_n4  = ch->counts[CHET_V4];
681 			strscpy(vparams.cvp_label4, vendor_labels[3],
682 				sizeof(vparams.cvp_label4));
683 		}
684 		if (copy_to_user(argp, &vparams, sizeof(vparams)))
685 			return -EFAULT;
686 		return 0;
687 	}
688 
689 	case CHIOPOSITION:
690 	{
691 		struct changer_position pos;
692 
693 		if (copy_from_user(&pos, argp, sizeof (pos)))
694 			return -EFAULT;
695 
696 		if (0 != ch_checkrange(ch, pos.cp_type, pos.cp_unit)) {
697 			DPRINTK("CHIOPOSITION: invalid parameter\n");
698 			return -EBADSLT;
699 		}
700 		mutex_lock(&ch->lock);
701 		retval = ch_position(ch,0,
702 				     ch->firsts[pos.cp_type] + pos.cp_unit,
703 				     pos.cp_flags & CP_INVERT);
704 		mutex_unlock(&ch->lock);
705 		return retval;
706 	}
707 
708 	case CHIOMOVE:
709 	{
710 		struct changer_move mv;
711 
712 		if (copy_from_user(&mv, argp, sizeof (mv)))
713 			return -EFAULT;
714 
715 		if (0 != ch_checkrange(ch, mv.cm_fromtype, mv.cm_fromunit) ||
716 		    0 != ch_checkrange(ch, mv.cm_totype,   mv.cm_tounit  )) {
717 			DPRINTK("CHIOMOVE: invalid parameter\n");
718 			return -EBADSLT;
719 		}
720 
721 		mutex_lock(&ch->lock);
722 		retval = ch_move(ch,0,
723 				 ch->firsts[mv.cm_fromtype] + mv.cm_fromunit,
724 				 ch->firsts[mv.cm_totype]   + mv.cm_tounit,
725 				 mv.cm_flags & CM_INVERT);
726 		mutex_unlock(&ch->lock);
727 		return retval;
728 	}
729 
730 	case CHIOEXCHANGE:
731 	{
732 		struct changer_exchange mv;
733 
734 		if (copy_from_user(&mv, argp, sizeof (mv)))
735 			return -EFAULT;
736 
737 		if (0 != ch_checkrange(ch, mv.ce_srctype,  mv.ce_srcunit ) ||
738 		    0 != ch_checkrange(ch, mv.ce_fdsttype, mv.ce_fdstunit) ||
739 		    0 != ch_checkrange(ch, mv.ce_sdsttype, mv.ce_sdstunit)) {
740 			DPRINTK("CHIOEXCHANGE: invalid parameter\n");
741 			return -EBADSLT;
742 		}
743 
744 		mutex_lock(&ch->lock);
745 		retval = ch_exchange
746 			(ch,0,
747 			 ch->firsts[mv.ce_srctype]  + mv.ce_srcunit,
748 			 ch->firsts[mv.ce_fdsttype] + mv.ce_fdstunit,
749 			 ch->firsts[mv.ce_sdsttype] + mv.ce_sdstunit,
750 			 mv.ce_flags & CE_INVERT1, mv.ce_flags & CE_INVERT2);
751 		mutex_unlock(&ch->lock);
752 		return retval;
753 	}
754 
755 	case CHIOGSTATUS:
756 	{
757 		struct changer_element_status ces;
758 
759 		if (copy_from_user(&ces, argp, sizeof (ces)))
760 			return -EFAULT;
761 		if (ces.ces_type < 0 || ces.ces_type >= CH_TYPES)
762 			return -EINVAL;
763 
764 		return ch_gstatus(ch, ces.ces_type, ces.ces_data);
765 	}
766 #ifdef CONFIG_COMPAT
767 	case CHIOGSTATUS32:
768 	{
769 		struct changer_element_status32 ces32;
770 
771 		if (copy_from_user(&ces32, argp, sizeof(ces32)))
772 			return -EFAULT;
773 		if (ces32.ces_type < 0 || ces32.ces_type >= CH_TYPES)
774 			return -EINVAL;
775 
776 		return ch_gstatus(ch, ces32.ces_type,
777 				  compat_ptr(ces32.ces_data));
778 	}
779 #endif
780 	case CHIOGELEM:
781 	{
782 		struct changer_get_element cge;
783 		u_char ch_cmd[12];
784 		u_char *buffer;
785 		unsigned int elem;
786 		int     result,i;
787 
788 		if (copy_from_user(&cge, argp, sizeof (cge)))
789 			return -EFAULT;
790 
791 		if (0 != ch_checkrange(ch, cge.cge_type, cge.cge_unit))
792 			return -EINVAL;
793 		elem = ch->firsts[cge.cge_type] + cge.cge_unit;
794 
795 		buffer = kmalloc(512, GFP_KERNEL);
796 		if (!buffer)
797 			return -ENOMEM;
798 		mutex_lock(&ch->lock);
799 
800 	voltag_retry:
801 		memset(ch_cmd, 0, sizeof(ch_cmd));
802 		ch_cmd[0] = READ_ELEMENT_STATUS;
803 		ch_cmd[1] = ((ch->device->lun & 0x7) << 5) |
804 			(ch->voltags ? 0x10 : 0) |
805 			ch_elem_to_typecode(ch,elem);
806 		ch_cmd[2] = (elem >> 8) & 0xff;
807 		ch_cmd[3] = elem        & 0xff;
808 		ch_cmd[5] = 1;
809 		ch_cmd[9] = 255;
810 
811 		result = ch_do_scsi(ch, ch_cmd, 12, buffer, 256, REQ_OP_DRV_IN);
812 		if (!result) {
813 			cge.cge_status = buffer[18];
814 			cge.cge_flags = 0;
815 			if (buffer[18] & CESTATUS_EXCEPT) {
816 				cge.cge_errno = EIO;
817 			}
818 			if (buffer[25] & 0x80) {
819 				cge.cge_flags |= CGE_SRC;
820 				if (buffer[25] & 0x40)
821 					cge.cge_flags |= CGE_INVERT;
822 				elem = (buffer[26]<<8) | buffer[27];
823 				for (i = 0; i < 4; i++) {
824 					if (elem >= ch->firsts[i] &&
825 					    elem <  ch->firsts[i] + ch->counts[i]) {
826 						cge.cge_srctype = i;
827 						cge.cge_srcunit = elem-ch->firsts[i];
828 					}
829 				}
830 			}
831 			if ((buffer[22] & 0x30) == 0x30) {
832 				cge.cge_flags |= CGE_IDLUN;
833 				cge.cge_id  = buffer[23];
834 				cge.cge_lun = buffer[22] & 7;
835 			}
836 			if (buffer[9] & 0x80) {
837 				cge.cge_flags |= CGE_PVOLTAG;
838 				memcpy(cge.cge_pvoltag,buffer+28,36);
839 			}
840 			if (buffer[9] & 0x40) {
841 				cge.cge_flags |= CGE_AVOLTAG;
842 				memcpy(cge.cge_avoltag,buffer+64,36);
843 			}
844 		} else if (ch->voltags) {
845 			ch->voltags = 0;
846 			VPRINTK(KERN_INFO, "device has no volume tag support\n");
847 			goto voltag_retry;
848 		}
849 		kfree(buffer);
850 		mutex_unlock(&ch->lock);
851 
852 		if (copy_to_user(argp, &cge, sizeof (cge)))
853 			return -EFAULT;
854 		return result;
855 	}
856 
857 	case CHIOINITELEM:
858 	{
859 		mutex_lock(&ch->lock);
860 		retval = ch_init_elem(ch);
861 		mutex_unlock(&ch->lock);
862 		return retval;
863 	}
864 
865 	case CHIOSVOLTAG:
866 	{
867 		struct changer_set_voltag csv;
868 		int elem;
869 
870 		if (copy_from_user(&csv, argp, sizeof(csv)))
871 			return -EFAULT;
872 
873 		if (0 != ch_checkrange(ch, csv.csv_type, csv.csv_unit)) {
874 			DPRINTK("CHIOSVOLTAG: invalid parameter\n");
875 			return -EBADSLT;
876 		}
877 		elem = ch->firsts[csv.csv_type] + csv.csv_unit;
878 		mutex_lock(&ch->lock);
879 		retval = ch_set_voltag(ch, elem,
880 				       csv.csv_flags & CSV_AVOLTAG,
881 				       csv.csv_flags & CSV_CLEARTAG,
882 				       csv.csv_voltag);
883 		mutex_unlock(&ch->lock);
884 		return retval;
885 	}
886 
887 	default:
888 		return scsi_ioctl(ch->device, file->f_mode & FMODE_WRITE, cmd,
889 				  argp);
890 
891 	}
892 }
893 
894 /* ------------------------------------------------------------------------ */
895 
896 static int ch_probe(struct scsi_device *sd)
897 {
898 	struct device *dev = &sd->sdev_gendev;
899 	struct device *class_dev;
900 	int ret;
901 	scsi_changer *ch;
902 
903 	if (sd->type != TYPE_MEDIUM_CHANGER)
904 		return -ENODEV;
905 
906 	ch = kzalloc_obj(*ch, GFP_KERNEL);
907 	if (NULL == ch)
908 		return -ENOMEM;
909 
910 	idr_preload(GFP_KERNEL);
911 	spin_lock(&ch_index_lock);
912 	ret = idr_alloc(&ch_index_idr, ch, 0, CH_MAX_DEVS + 1, GFP_NOWAIT);
913 	spin_unlock(&ch_index_lock);
914 	idr_preload_end();
915 
916 	if (ret < 0) {
917 		if (ret == -ENOSPC)
918 			ret = -ENODEV;
919 		goto free_ch;
920 	}
921 
922 	ch->minor = ret;
923 	sprintf(ch->name,"ch%d",ch->minor);
924 	ret = scsi_device_get(sd);
925 	if (ret) {
926 		sdev_printk(KERN_WARNING, sd, "ch%d: failed to get device\n",
927 			    ch->minor);
928 		goto remove_idr;
929 	}
930 
931 	mutex_init(&ch->lock);
932 	kref_init(&ch->ref);
933 	ch->device = sd;
934 	class_dev = device_create(&ch_sysfs_class, dev,
935 				  MKDEV(SCSI_CHANGER_MAJOR, ch->minor), ch,
936 				  "s%s", ch->name);
937 	if (IS_ERR(class_dev)) {
938 		sdev_printk(KERN_WARNING, sd, "ch%d: device_create failed\n",
939 			    ch->minor);
940 		ret = PTR_ERR(class_dev);
941 		goto put_device;
942 	}
943 
944 	mutex_lock(&ch->lock);
945 	ret = ch_readconfig(ch);
946 	if (ret) {
947 		mutex_unlock(&ch->lock);
948 		goto destroy_dev;
949 	}
950 	if (init)
951 		ch_init_elem(ch);
952 
953 	mutex_unlock(&ch->lock);
954 	dev_set_drvdata(dev, ch);
955 	sdev_printk(KERN_INFO, sd, "Attached scsi changer %s\n", ch->name);
956 
957 	return 0;
958 destroy_dev:
959 	device_destroy(&ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
960 put_device:
961 	scsi_device_put(sd);
962 remove_idr:
963 	idr_remove(&ch_index_idr, ch->minor);
964 free_ch:
965 	kfree(ch);
966 	return ret;
967 }
968 
969 static void ch_remove(struct scsi_device *sd)
970 {
971 	struct device *dev = &sd->sdev_gendev;
972 	scsi_changer *ch = dev_get_drvdata(dev);
973 
974 	spin_lock(&ch_index_lock);
975 	idr_remove(&ch_index_idr, ch->minor);
976 	dev_set_drvdata(dev, NULL);
977 	spin_unlock(&ch_index_lock);
978 
979 	device_destroy(&ch_sysfs_class, MKDEV(SCSI_CHANGER_MAJOR, ch->minor));
980 	scsi_device_put(ch->device);
981 	kref_put(&ch->ref, ch_destroy);
982 }
983 
984 static struct scsi_driver ch_template = {
985 	.probe = ch_probe,
986 	.remove = ch_remove,
987 	.gendrv = {
988 		.name	= "ch",
989 		.owner	= THIS_MODULE,
990 	},
991 };
992 
993 static const struct file_operations changer_fops = {
994 	.owner		= THIS_MODULE,
995 	.open		= ch_open,
996 	.release	= ch_release,
997 	.unlocked_ioctl	= ch_ioctl,
998 	.compat_ioctl	= compat_ptr_ioctl,
999 	.llseek		= noop_llseek,
1000 };
1001 
1002 static int __init init_ch_module(void)
1003 {
1004 	int rc;
1005 
1006 	printk(KERN_INFO "SCSI Media Changer driver v" VERSION " \n");
1007 	rc = class_register(&ch_sysfs_class);
1008 	if (rc)
1009 		return rc;
1010 	rc = register_chrdev(SCSI_CHANGER_MAJOR,"ch",&changer_fops);
1011 	if (rc < 0) {
1012 		printk("Unable to get major %d for SCSI-Changer\n",
1013 		       SCSI_CHANGER_MAJOR);
1014 		goto fail1;
1015 	}
1016 	rc = scsi_register_driver(&ch_template);
1017 	if (rc < 0)
1018 		goto fail2;
1019 	return 0;
1020 
1021  fail2:
1022 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1023  fail1:
1024 	class_unregister(&ch_sysfs_class);
1025 	return rc;
1026 }
1027 
1028 static void __exit exit_ch_module(void)
1029 {
1030 	scsi_unregister_driver(&ch_template);
1031 	unregister_chrdev(SCSI_CHANGER_MAJOR, "ch");
1032 	class_unregister(&ch_sysfs_class);
1033 	idr_destroy(&ch_index_idr);
1034 }
1035 
1036 module_init(init_ch_module);
1037 module_exit(exit_ch_module);
1038