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