aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/block/acsi.c
blob: 706cdc6a69eca719c856bc3c65575e77804036a7 (plain) (tree)
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594












































                                                                             













                                                     
































































































































































































































































































                                                                                                 
                                                        





















                                                                           
                                               



































































































































































































































































































































































                                                                                                                         
                                                       






























































































































































































































































































































































                                                                                                      












                                                                          






                                                                                













































































































































































































































































































































































































































































































                                                                                                   
                                      









































































































































                                                                                          

                                           
                                                  
                                         
























































































                                                                                  
/*
 * acsi.c -- Device driver for Atari ACSI hard disks
 *
 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
 *
 * Some parts are based on hd.c by Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 *
 */

/*
 * Still to in this file:
 *  - If a command ends with an error status (!= 0), the following
 *    REQUEST SENSE commands (4 to fill the ST-DMA FIFO) are done by
 *    polling the _IRQ signal (not interrupt-driven). This should be
 *    avoided in future because it takes up a non-neglectible time in
 *    the interrupt service routine while interrupts are disabled.
 *    Maybe a timer interrupt will get lost :-(
 */

/*
 * General notes:
 *
 *  - All ACSI devices (disks, CD-ROMs, ...) use major number 28.
 *    Minors are organized like it is with SCSI: The upper 4 bits
 *    identify the device, the lower 4 bits the partition.
 *    The device numbers (the upper 4 bits) are given in the same
 *    order as the devices are found on the bus.
 *  - Up to 8 LUNs are supported for each target (if CONFIG_ACSI_MULTI_LUN
 *    is defined), but only a total of 16 devices (due to minor
 *    numbers...). Note that Atari allows only a maximum of 4 targets
 *    (i.e. controllers, not devices) on the ACSI bus!
 *  - A optimizing scheme similar to SCSI scatter-gather is implemented.
 *  - Removable media are supported. After a medium change to device
 *    is reinitialized (partition check etc.). Also, if the device
 *    knows the PREVENT/ALLOW MEDIUM REMOVAL command, the door should
 *    be locked and unlocked when mounting the first or unmounting the
 *    last filesystem on the device. The code is untested, because I
 *    don't have a removable hard disk.
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/genhd.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <scsi/scsi.h> /* for SCSI_IOCTL_GET_IDLUN */
#include <scsi/scsi_ioctl.h>
#include <linux/hdreg.h> /* for HDIO_GETGEO */
#include <linux/blkpg.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>

#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/atarihw.h>
#include <asm/atariints.h>
#include <asm/atari_acsi.h>
#include <asm/atari_stdma.h>
#include <asm/atari_stram.h>

static void (*do_acsi)(void) = NULL;
static struct request_queue *acsi_queue;
#define QUEUE (acsi_queue)
#define CURRENT elv_next_request(acsi_queue)

#define DEBUG
#undef DEBUG_DETECT
#undef NO_WRITE

#define MAX_ERRORS     		8	/* Max read/write errors/sector */
#define MAX_LUN				8	/* Max LUNs per target */
#define MAX_DEV		   		16

#define ACSI_BUFFER_SIZE			(16*1024) /* "normal" ACSI buffer size */
#define ACSI_BUFFER_MINSIZE			(2048) 	  /* min. buf size if ext. DMA */
#define ACSI_BUFFER_SIZE_ORDER	 	2		  /* order size for above */
#define ACSI_BUFFER_MINSIZE_ORDER	0 	  	  /* order size for above */
#define ACSI_BUFFER_SECTORS	(ACSI_BUFFER_SIZE/512)

#define ACSI_BUFFER_ORDER \
	(ATARIHW_PRESENT(EXTD_DMA) ? \
	 ACSI_BUFFER_MINSIZE_ORDER : \
	 ACSI_BUFFER_SIZE_ORDER)

#define ACSI_TIMEOUT		(4*HZ)

/* minimum delay between two commands */

#define COMMAND_DELAY 500

typedef enum {
	NONE, HARDDISK, CDROM
} ACSI_TYPE;

struct acsi_info_struct {
	ACSI_TYPE		type;			/* type of device */
	unsigned		target;			/* target number */
	unsigned		lun;			/* LUN in target controller */
	unsigned		removable : 1;	/* Flag for removable media */
	unsigned		read_only : 1;	/* Flag for read only devices */
	unsigned		old_atari_disk : 1; /* Is an old Atari disk       */
	unsigned		changed : 1;	/* Medium has been changed */
	unsigned long 	size;			/* #blocks */
	int access_count;
} acsi_info[MAX_DEV];

/*
 *	SENSE KEYS
 */

#define NO_SENSE		0x00
#define RECOVERED_ERROR 	0x01
#define NOT_READY		0x02
#define MEDIUM_ERROR		0x03
#define HARDWARE_ERROR		0x04
#define ILLEGAL_REQUEST 	0x05
#define UNIT_ATTENTION		0x06
#define DATA_PROTECT		0x07
#define BLANK_CHECK		0x08
#define COPY_ABORTED		0x0a
#define ABORTED_COMMAND 	0x0b
#define VOLUME_OVERFLOW 	0x0d
#define MISCOMPARE		0x0e


/*
 *	DEVICE TYPES
 */

#define TYPE_DISK	0x00
#define TYPE_TAPE	0x01
#define TYPE_WORM	0x04
#define TYPE_ROM	0x05
#define TYPE_MOD	0x07
#define TYPE_NO_LUN	0x7f

/* The data returned by MODE SENSE differ between the old Atari
 * hard disks and SCSI disks connected to ACSI. In the following, both
 * formats are defined and some macros to operate on them potably.
 */

typedef struct {
	unsigned long	dummy[2];
	unsigned long	sector_size;
	unsigned char	format_code;
#define ATARI_SENSE_FORMAT_FIX	1	
#define ATARI_SENSE_FORMAT_CHNG	2
	unsigned char	cylinders_h;
	unsigned char	cylinders_l;
	unsigned char	heads;
	unsigned char	reduced_h;
	unsigned char	reduced_l;
	unsigned char	precomp_h;
	unsigned char	precomp_l;
	unsigned char	landing_zone;
	unsigned char	steprate;
	unsigned char	type;
#define ATARI_SENSE_TYPE_FIXCHNG_MASK		4
#define ATARI_SENSE_TYPE_SOFTHARD_MASK		8
#define ATARI_SENSE_TYPE_FIX				4
#define ATARI_SENSE_TYPE_CHNG				0
#define ATARI_SENSE_TYPE_SOFT				0
#define ATARI_SENSE_TYPE_HARD				8
	unsigned char	sectors;
} ATARI_SENSE_DATA;

#define ATARI_CAPACITY(sd) \
	(((int)((sd).cylinders_h<<8)|(sd).cylinders_l) * \
	 (sd).heads * (sd).sectors)


typedef struct {
	unsigned char   dummy1;
	unsigned char   medium_type;
	unsigned char   dummy2;
	unsigned char   descriptor_size;
	unsigned long   block_count;
	unsigned long   sector_size;
	/* Page 0 data */
	unsigned char	page_code;
	unsigned char	page_size;
	unsigned char	page_flags;
	unsigned char	qualifier;
} SCSI_SENSE_DATA;

#define SCSI_CAPACITY(sd) 	((sd).block_count & 0xffffff)


typedef union {
	ATARI_SENSE_DATA	atari;
	SCSI_SENSE_DATA		scsi;
} SENSE_DATA;

#define SENSE_TYPE_UNKNOWN	0
#define SENSE_TYPE_ATARI	1
#define SENSE_TYPE_SCSI		2

#define SENSE_TYPE(sd)										\
	(((sd).atari.dummy[0] == 8 &&							\
	  ((sd).atari.format_code == 1 ||						\
	   (sd).atari.format_code == 2)) ? SENSE_TYPE_ATARI :	\
	 ((sd).scsi.dummy1 >= 11) ? SENSE_TYPE_SCSI :			\
	 SENSE_TYPE_UNKNOWN)
	 
#define CAPACITY(sd)							\
	(SENSE_TYPE(sd) == SENSE_TYPE_ATARI ?		\
	 ATARI_CAPACITY((sd).atari) :				\
	 SCSI_CAPACITY((sd).scsi))

#define SECTOR_SIZE(sd)							\
	(SENSE_TYPE(sd) == SENSE_TYPE_ATARI ?		\
	 (sd).atari.sector_size :					\
	 (sd).scsi.sector_size & 0xffffff)

/* Default size if capacity cannot be determined (1 GByte) */
#define	DEFAULT_SIZE	0x1fffff

#define CARTRCH_STAT(aip,buf)						\
	(aip->old_atari_disk ?						\
	 (((buf)[0] & 0x7f) == 0x28) :					\
	 ((((buf)[0] & 0x70) == 0x70) ?					\
	  (((buf)[2] & 0x0f) == 0x06) :					\
	  (((buf)[0] & 0x0f) == 0x06)))					\

/* These two are also exported to other drivers that work on the ACSI bus and
 * need an ST-RAM buffer. */
char 			*acsi_buffer;
unsigned long 	phys_acsi_buffer;

static int NDevices;

static int				CurrentNReq;
static int				CurrentNSect;
static char				*CurrentBuffer;

static DEFINE_SPINLOCK(acsi_lock);


#define SET_TIMER()	mod_timer(&acsi_timer, jiffies + ACSI_TIMEOUT)
#define CLEAR_TIMER()	del_timer(&acsi_timer)

static unsigned long	STramMask;
#define STRAM_ADDR(a)	(((a) & STramMask) == 0)



/* ACSI commands */

static char tur_cmd[6]        = { 0x00, 0, 0, 0, 0, 0 };
static char modesense_cmd[6]  = { 0x1a, 0, 0, 0, 24, 0 };
static char modeselect_cmd[6] = { 0x15, 0, 0, 0, 12, 0 };
static char inquiry_cmd[6]    = { 0x12, 0, 0, 0,255, 0 };
static char reqsense_cmd[6]   = { 0x03, 0, 0, 0, 4, 0 };
static char read_cmd[6]       = { 0x08, 0, 0, 0, 0, 0 };
static char write_cmd[6]      = { 0x0a, 0, 0, 0, 0, 0 };
static char pa_med_rem_cmd[6] = { 0x1e, 0, 0, 0, 0, 0 };

#define CMDSET_TARG_LUN(cmd,targ,lun)			\
    do {						\
		cmd[0] = (cmd[0] & ~0xe0) | (targ)<<5;	\
		cmd[1] = (cmd[1] & ~0xe0) | (lun)<<5;	\
	} while(0)

#define CMDSET_BLOCK(cmd,blk)						\
    do {											\
		unsigned long __blk = (blk);				\
		cmd[3] = __blk; __blk >>= 8;				\
		cmd[2] = __blk; __blk >>= 8;				\
		cmd[1] = (cmd[1] & 0xe0) | (__blk & 0x1f);	\
	} while(0)

#define CMDSET_LEN(cmd,len)						\
	do {										\
		cmd[4] = (len);							\
	} while(0)

/* ACSI errors (from REQUEST SENSE); There are two tables, one for the
 * old Atari disks and one for SCSI on ACSI disks.
 */

struct acsi_error {
	unsigned char	code;
	const char		*text;
} atari_acsi_errors[] = {
	{ 0x00, "No error (??)" },
	{ 0x01, "No index pulses" },
	{ 0x02, "Seek not complete" },
	{ 0x03, "Write fault" },
	{ 0x04, "Drive not ready" },
	{ 0x06, "No Track 00 signal" },
	{ 0x10, "ECC error in ID field" },
	{ 0x11, "Uncorrectable data error" },
	{ 0x12, "ID field address mark not found" },
	{ 0x13, "Data field address mark not found" },
	{ 0x14, "Record not found" },
	{ 0x15, "Seek error" },
	{ 0x18, "Data check in no retry mode" },
	{ 0x19, "ECC error during verify" },
	{ 0x1a, "Access to bad block" },
	{ 0x1c, "Unformatted or bad format" },
	{ 0x20, "Invalid command" },
	{ 0x21, "Invalid block address" },
	{ 0x23, "Volume overflow" },
	{ 0x24, "Invalid argument" },
	{ 0x25, "Invalid drive number" },
	{ 0x26, "Byte zero parity check" },
	{ 0x28, "Cartride changed" },
	{ 0x2c, "Error count overflow" },
	{ 0x30, "Controller selftest failed" }
},

	scsi_acsi_errors[] = {
	{ 0x00, "No error (??)" },
	{ 0x01, "Recovered error" },
	{ 0x02, "Drive not ready" },
	{ 0x03, "Uncorrectable medium error" },
	{ 0x04, "Hardware error" },
	{ 0x05, "Illegal request" },
	{ 0x06, "Unit attention (Reset or cartridge changed)" },
	{ 0x07, "Data protection" },
	{ 0x08, "Blank check" },
	{ 0x0b, "Aborted Command" },
	{ 0x0d, "Volume overflow" }
};



/***************************** Prototypes *****************************/

static int acsicmd_dma( const char *cmd, char *buffer, int blocks, int
                        rwflag, int enable);
static int acsi_reqsense( char *buffer, int targ, int lun);
static void acsi_print_error(const unsigned char *errblk, struct acsi_info_struct *aip);
static irqreturn_t acsi_interrupt (int irq, void *data);
static void unexpected_acsi_interrupt( void );
static void bad_rw_intr( void );
static void read_intr( void );
static void write_intr( void);
static void acsi_times_out( unsigned long dummy );
static void copy_to_acsibuffer( void );
static void copy_from_acsibuffer( void );
static void do_end_requests( void );
static void do_acsi_request( request_queue_t * );
static void redo_acsi_request( void );
static int acsi_ioctl( struct inode *inode, struct file *file, unsigned int
                       cmd, unsigned long arg );
static int acsi_open( struct inode * inode, struct file * filp );
static int acsi_release( struct inode * inode, struct file * file );
static void acsi_prevent_removal(struct acsi_info_struct *aip, int flag );
static int acsi_change_blk_size( int target, int lun);
static int acsi_mode_sense( int target, int lun, SENSE_DATA *sd );
static int acsi_revalidate (struct gendisk *disk);

/************************* End of Prototypes **************************/


DEFINE_TIMER(acsi_timer, acsi_times_out, 0, 0);


#ifdef CONFIG_ATARI_SLM

extern int attach_slm( int target, int lun );
extern int slm_init( void );

#endif



/***********************************************************************
 *
 *   ACSI primitives
 *
 **********************************************************************/


/*
 * The following two functions wait for _IRQ to become Low or High,
 * resp., with a timeout. The 'timeout' parameter is in jiffies
 * (10ms).
 * If the functions are called with timer interrupts on (int level <
 * 6), the timeout is based on the 'jiffies' variable to provide exact
 * timeouts for device probing etc.
 * If interrupts are disabled, the number of tries is based on the
 * 'loops_per_jiffy' variable. A rough estimation is sufficient here...
 */

#define INT_LEVEL													\
	({	unsigned __sr;												\
		__asm__ __volatile__ ( "movew	%/sr,%0" : "=dm" (__sr) );	\
		(__sr >> 8) & 7;											\
	})

int acsi_wait_for_IRQ( unsigned timeout )

{
	if (INT_LEVEL < 6) {
		unsigned long maxjif = jiffies + timeout;
		while (time_before(jiffies, maxjif))
			if (!(mfp.par_dt_reg & 0x20)) return( 1 );
	}
	else {
		long tries = loops_per_jiffy / 8 * timeout;
		while( --tries >= 0 )
			if (!(mfp.par_dt_reg & 0x20)) return( 1 );
	}		
	return( 0 ); /* timeout! */
}


int acsi_wait_for_noIRQ( unsigned timeout )

{
	if (INT_LEVEL < 6) {
		unsigned long maxjif = jiffies + timeout;
		while (time_before(jiffies, maxjif))
			if (mfp.par_dt_reg & 0x20) return( 1 );
	}
	else {
		long tries = loops_per_jiffy * timeout / 8;
		while( tries-- >= 0 )
			if (mfp.par_dt_reg & 0x20) return( 1 );
	}		
	return( 0 ); /* timeout! */
}

static struct timeval start_time;

void
acsi_delay_start(void)
{
	do_gettimeofday(&start_time);
}

/* wait from acsi_delay_start to now usec (<1E6) usec */

void
acsi_delay_end(long usec)
{
	struct timeval end_time;
	long deltau,deltas;
	do_gettimeofday(&end_time);
	deltau=end_time.tv_usec - start_time.tv_usec;
	deltas=end_time.tv_sec - start_time.tv_sec;
	if (deltas > 1 || deltas < 0)
		return;
	if (deltas > 0)
		deltau += 1000*1000;
	if (deltau >= usec)
		return;
	udelay(usec-deltau);
}

/* acsicmd_dma() sends an ACSI command and sets up the DMA to transfer
 * 'blocks' blocks of 512 bytes from/to 'buffer'.
 * Because the _IRQ signal is used for handshaking the command bytes,
 * the ACSI interrupt has to be disabled in this function. If the end
 * of the operation should be signalled by a real interrupt, it has to be
 * reenabled afterwards.
 */

static int acsicmd_dma( const char *cmd, char *buffer, int blocks, int rwflag, int enable)

{	unsigned long	flags, paddr;
	int				i;

#ifdef NO_WRITE
	if (rwflag || *cmd == 0x0a) {
		printk( "ACSI: Write commands disabled!\n" );
		return( 0 );
	}
#endif
	
	rwflag = rwflag ? 0x100 : 0;
	paddr = virt_to_phys( buffer );

	acsi_delay_end(COMMAND_DELAY);
	DISABLE_IRQ();

	local_irq_save(flags);
	/* Low on A1 */
	dma_wd.dma_mode_status = 0x88 | rwflag;
	MFPDELAY();

	/* set DMA address */
	dma_wd.dma_lo = (unsigned char)paddr;
	paddr >>= 8;
	MFPDELAY();
	dma_wd.dma_md = (unsigned char)paddr;
	paddr >>= 8;
	MFPDELAY();
	if (ATARIHW_PRESENT(EXTD_DMA))
		st_dma_ext_dmahi = (unsigned short)paddr;
	else
		dma_wd.dma_hi = (unsigned char)paddr;
	MFPDELAY();
	local_irq_restore(flags);

	/* send the command bytes except the last */
	for( i = 0; i < 5; ++i ) {
		DMA_LONG_WRITE( *cmd++, 0x8a | rwflag );
		udelay(20);
		if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */
	}

	/* Clear FIFO and switch DMA to correct direction */  
	dma_wd.dma_mode_status = 0x92 | (rwflag ^ 0x100);  
	MFPDELAY();
	dma_wd.dma_mode_status = 0x92 | rwflag;
	MFPDELAY();

	/* How many sectors for DMA */
	dma_wd.fdc_acces_seccount = blocks;
	MFPDELAY();
	
	/* send last command byte */
	dma_wd.dma_mode_status = 0x8a | rwflag;
	MFPDELAY();
	DMA_LONG_WRITE( *cmd++, 0x0a | rwflag );
	if (enable)
		ENABLE_IRQ();
	udelay(80);

	return( 1 );
}


/*
 * acsicmd_nodma() sends an ACSI command that requires no DMA.
 */

int acsicmd_nodma( const char *cmd, int enable)

{	int	i;

	acsi_delay_end(COMMAND_DELAY);
	DISABLE_IRQ();

	/* send first command byte */
	dma_wd.dma_mode_status = 0x88;
	MFPDELAY();
	DMA_LONG_WRITE( *cmd++, 0x8a );
	udelay(20);
	if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */

	/* send the intermediate command bytes */
	for( i = 0; i < 4; ++i ) {
		DMA_LONG_WRITE( *cmd++, 0x8a );
		udelay(20);
		if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */
	}

	/* send last command byte */
	DMA_LONG_WRITE( *cmd++, 0x0a );
	if (enable)
		ENABLE_IRQ();
	udelay(80);
	
	return( 1 );
	/* Note that the ACSI interrupt is still disabled after this
	 * function. If you want to get the IRQ delivered, enable it manually!
	 */
}


static int acsi_reqsense( char *buffer, int targ, int lun)

{
	CMDSET_TARG_LUN( reqsense_cmd, targ, lun);
	if (!acsicmd_dma( reqsense_cmd, buffer, 1, 0, 0 )) return( 0 );
	if (!acsi_wait_for_IRQ( 10 )) return( 0 );
	acsi_getstatus();
	if (!acsicmd_nodma( reqsense_cmd, 0 )) return( 0 );
	if (!acsi_wait_for_IRQ( 10 )) return( 0 );
	acsi_getstatus();
	if (!acsicmd_nodma( reqsense_cmd, 0 )) return( 0 );
	if (!acsi_wait_for_IRQ( 10 )) return( 0 );
	acsi_getstatus();
	if (!acsicmd_nodma( reqsense_cmd, 0 )) return( 0 );
	if (!acsi_wait_for_IRQ( 10 )) return( 0 );
	acsi_getstatus();
	dma_cache_maintenance( virt_to_phys(buffer), 16, 0 );
	
	return( 1 );
}	


/*
 * ACSI status phase: get the status byte from the bus
 *
 * I've seen several times that a 0xff status is read, propably due to
 * a timing error. In this case, the procedure is repeated after the
 * next _IRQ edge.
 */

int acsi_getstatus( void )

{	int	status;

	DISABLE_IRQ();
	for(;;) {
		if (!acsi_wait_for_IRQ( 100 )) {
			acsi_delay_start();
			return( -1 );
		}
		dma_wd.dma_mode_status = 0x8a;
		MFPDELAY();
		status = dma_wd.fdc_acces_seccount;
		if (status != 0xff) break;
#ifdef DEBUG
		printk("ACSI: skipping 0xff status byte\n" );
#endif
		udelay(40);
		acsi_wait_for_noIRQ( 20 );
	}
	dma_wd.dma_mode_status = 0x80;
	udelay(40);
	acsi_wait_for_noIRQ( 20 );

	acsi_delay_start();
	return( status & 0x1f ); /* mask of the device# */
}


#if (defined(CONFIG_ATARI_SLM) || defined(CONFIG_ATARI_SLM_MODULE))

/* Receive data in an extended status phase. Needed by SLM printer. */

int acsi_extstatus( char *buffer, int cnt )

{	int	status;

	DISABLE_IRQ();
	udelay(80);
	while( cnt-- > 0 ) {
		if (!acsi_wait_for_IRQ( 40 )) return( 0 );
		dma_wd.dma_mode_status = 0x8a;
		MFPDELAY();
		status = dma_wd.fdc_acces_seccount;
		MFPDELAY();
		*buffer++ = status & 0xff;
		udelay(40);
	}
	return( 1 );
}


/* Finish an extended status phase */

void acsi_end_extstatus( void )

{
	dma_wd.dma_mode_status = 0x80;
	udelay(40);
	acsi_wait_for_noIRQ( 20 );
	acsi_delay_start();
}


/* Send data in an extended command phase */

int acsi_extcmd( unsigned char *buffer, int cnt )

{
	while( cnt-- > 0 ) {
		DMA_LONG_WRITE( *buffer++, 0x8a );
		udelay(20);
		if (!acsi_wait_for_IRQ( HZ/2 )) return( 0 ); /* timeout */
	}
	return( 1 );
}

#endif


static void acsi_print_error(const unsigned char *errblk, struct acsi_info_struct *aip)

{	int atari_err, i, errcode;
	struct acsi_error *arr;

	atari_err = aip->old_atari_disk;
	if (atari_err)
		errcode = errblk[0] & 0x7f;
	else
		if ((errblk[0] & 0x70) == 0x70)
			errcode = errblk[2] & 0x0f;
		else
			errcode = errblk[0] & 0x0f;
	
	printk( KERN_ERR "ACSI error 0x%02x", errcode );

	if (errblk[0] & 0x80)
		printk( " for sector %d",
				((errblk[1] & 0x1f) << 16) |
				(errblk[2] << 8) | errblk[0] );

	arr = atari_err ? atari_acsi_errors : scsi_acsi_errors;
	i = atari_err ? sizeof(atari_acsi_errors)/sizeof(*atari_acsi_errors) :
		            sizeof(scsi_acsi_errors)/sizeof(*scsi_acsi_errors);
	
	for( --i; i >= 0; --i )
		if (arr[i].code == errcode) break;
	if (i >= 0)
		printk( ": %s\n", arr[i].text );
}

/*******************************************************************
 *
 * ACSI interrupt routine
 *   Test, if this is a ACSI interrupt and call the irq handler
 *   Otherwise ignore this interrupt.
 *
 *******************************************************************/

static irqreturn_t acsi_interrupt(int irq, void *data )

{	void (*acsi_irq_handler)(void) = do_acsi;

	do_acsi = NULL;
	CLEAR_TIMER();

	if (!acsi_irq_handler)
		acsi_irq_handler = unexpected_acsi_interrupt;
	acsi_irq_handler();
	return IRQ_HANDLED;
}


/******************************************************************
 *
 * The Interrupt handlers
 *
 *******************************************************************/


static void unexpected_acsi_interrupt( void )

{
	printk( KERN_WARNING "Unexpected ACSI interrupt\n" );
}


/* This function is called in case of errors. Because we cannot reset
 * the ACSI bus or a single device, there is no other choice than
 * retrying several times :-(
 */

static void bad_rw_intr( void )

{
	if (!CURRENT)
		return;

	if (++CURRENT->errors >= MAX_ERRORS)
		end_request(CURRENT, 0);
	/* Otherwise just retry */
}


static void read_intr( void )

{	int		status;
	
	status = acsi_getstatus();
	if (status != 0) {
		struct gendisk *disk = CURRENT->rq_disk;
		struct acsi_info_struct *aip = disk->private_data;
		printk(KERN_ERR "%s: ", disk->disk_name);
		if (!acsi_reqsense(acsi_buffer, aip->target, aip->lun))
			printk( "ACSI error and REQUEST SENSE failed (status=0x%02x)\n", status );
		else {
			acsi_print_error(acsi_buffer, aip);
			if (CARTRCH_STAT(aip, acsi_buffer))
				aip->changed = 1;
		}
		ENABLE_IRQ();
		bad_rw_intr();
		redo_acsi_request();
		return;
	}

	dma_cache_maintenance( virt_to_phys(CurrentBuffer), CurrentNSect*512, 0 );
	if (CurrentBuffer == acsi_buffer)
		copy_from_acsibuffer();

	do_end_requests();
	redo_acsi_request();
}


static void write_intr(void)

{	int	status;

	status = acsi_getstatus();
	if (status != 0) {
		struct gendisk *disk = CURRENT->rq_disk;
		struct acsi_info_struct *aip = disk->private_data;
		printk( KERN_ERR "%s: ", disk->disk_name);
		if (!acsi_reqsense( acsi_buffer, aip->target, aip->lun))
			printk( "ACSI error and REQUEST SENSE failed (status=0x%02x)\n", status );
		else {
			acsi_print_error(acsi_buffer, aip);
			if (CARTRCH_STAT(aip, acsi_buffer))
				aip->changed = 1;
		}
		bad_rw_intr();
		redo_acsi_request();
		return;
	}

	do_end_requests();
	redo_acsi_request();
}


static void acsi_times_out( unsigned long dummy )

{
	DISABLE_IRQ();
	if (!do_acsi) return;

	do_acsi = NULL;
	printk( KERN_ERR "ACSI timeout\n" );
	if (!CURRENT)
	    return;
	if (++CURRENT->errors >= MAX_ERRORS) {
#ifdef DEBUG
		printk( KERN_ERR "ACSI: too many errors.\n" );
#endif
		end_request(CURRENT, 0);
	}

	redo_acsi_request();
}



/***********************************************************************
 *
 *  Scatter-gather utility functions
 *
 ***********************************************************************/


static void copy_to_acsibuffer( void )

{	int					i;
	char				*src, *dst;
	struct buffer_head	*bh;
	
	src = CURRENT->buffer;
	dst = acsi_buffer;
	bh = CURRENT->bh;

	if (!bh)
		memcpy( dst, src, CurrentNSect*512 );
	else
		for( i = 0; i < CurrentNReq; ++i ) {
			memcpy( dst, src, bh->b_size );
			dst += bh->b_size;
			if ((bh = bh->b_reqnext))
				src = bh->b_data;
		}
}


static void copy_from_acsibuffer( void )

{	int					i;
	char				*src, *dst;
	struct buffer_head	*bh;
	
	dst = CURRENT->buffer;
	src = acsi_buffer;
	bh = CURRENT->bh;

	if (!bh)
		memcpy( dst, src, CurrentNSect*512 );
	else
		for( i = 0; i < CurrentNReq; ++i ) {
			memcpy( dst, src, bh->b_size );
			src += bh->b_size;
			if ((bh = bh->b_reqnext))
				dst = bh->b_data;
		}
}


static void do_end_requests( void )

{	int		i, n;

	if (!CURRENT->bh) {
		CURRENT->nr_sectors -= CurrentNSect;
		CURRENT->current_nr_sectors -= CurrentNSect;
		CURRENT->sector += CurrentNSect;
		if (CURRENT->nr_sectors == 0)
			end_request(CURRENT, 1);
	}
	else {
		for( i = 0; i < CurrentNReq; ++i ) {
			n = CURRENT->bh->b_size >> 9;
			CURRENT->nr_sectors -= n;
			CURRENT->current_nr_sectors -= n;
			CURRENT->sector += n;
			end_request(CURRENT, 1);
		}
	}
}




/***********************************************************************
 *
 *  do_acsi_request and friends
 *
 ***********************************************************************/

static void do_acsi_request( request_queue_t * q )

{
	stdma_lock( acsi_interrupt, NULL );
	redo_acsi_request();
}


static void redo_acsi_request( void )
{
	unsigned			block, target, lun, nsect;
	char 				*buffer;
	unsigned long		pbuffer;
	struct buffer_head	*bh;
	struct gendisk *disk;
	struct acsi_info_struct *aip;

  repeat:
	CLEAR_TIMER();

	if (do_acsi)
		return;

	if (!CURRENT) {
		do_acsi = NULL;
		ENABLE_IRQ();
		stdma_release();
		return;
	}

	disk = CURRENT->rq_disk;
	aip = disk->private_data;
	if (CURRENT->bh) {
		if (!CURRENT->bh && !buffer_locked(CURRENT->bh))
			panic("ACSI: block not locked");
	}

	block = CURRENT->sector;
	if (block+CURRENT->nr_sectors >= get_capacity(disk)) {
#ifdef DEBUG
		printk( "%s: attempted access for blocks %d...%ld past end of device at block %ld.\n",
		       disk->disk_name,
		       block, block + CURRENT->nr_sectors - 1,
		       get_capacity(disk));
#endif
		end_request(CURRENT, 0);
		goto repeat;
	}
	if (aip->changed) {
		printk( KERN_NOTICE "%s: request denied because cartridge has "
				"been changed.\n", disk->disk_name);
		end_request(CURRENT, 0);
		goto repeat;
	}
	
	target = aip->target;
	lun    = aip->lun;

	/* Find out how many sectors should be transferred from/to
	 * consecutive buffers and thus can be done with a single command.
	 */
	buffer      = CURRENT->buffer;
	pbuffer     = virt_to_phys(buffer);
	nsect       = CURRENT->current_nr_sectors;
	CurrentNReq = 1;

	if ((bh = CURRENT->bh) && bh != CURRENT->bhtail) {
		if (!STRAM_ADDR(pbuffer)) {
			/* If transfer is done via the ACSI buffer anyway, we can
			 * assemble as much bh's as fit in the buffer.
			 */
			while( (bh = bh->b_reqnext) ) {
				if (nsect + (bh->b_size>>9) > ACSI_BUFFER_SECTORS) break;
				nsect += bh->b_size >> 9;
				++CurrentNReq;
				if (bh == CURRENT->bhtail) break;
			}
			buffer = acsi_buffer;
			pbuffer = phys_acsi_buffer;
		}
		else {
			unsigned long pendadr, pnewadr;
			pendadr = pbuffer + nsect*512;
			while( (bh = bh->b_reqnext) ) {
				pnewadr = virt_to_phys(bh->b_data);
				if (!STRAM_ADDR(pnewadr) || pendadr != pnewadr) break;
				nsect += bh->b_size >> 9;
				pendadr = pnewadr + bh->b_size;
				++CurrentNReq;
				if (bh == CURRENT->bhtail) break;
			}
		}
	}
	else {
		if (!STRAM_ADDR(pbuffer)) {
			buffer = acsi_buffer;
			pbuffer = phys_acsi_buffer;
			if (nsect > ACSI_BUFFER_SECTORS)
				nsect = ACSI_BUFFER_SECTORS;
		}
	}
	CurrentBuffer = buffer;
	CurrentNSect  = nsect;

	if (rq_data_dir(CURRENT) == WRITE) {
		CMDSET_TARG_LUN( write_cmd, target, lun );
		CMDSET_BLOCK( write_cmd, block );
		CMDSET_LEN( write_cmd, nsect );
		if (buffer == acsi_buffer)
			copy_to_acsibuffer();
		dma_cache_maintenance( pbuffer, nsect*512, 1 );
		do_acsi = write_intr;
		if (!acsicmd_dma( write_cmd, buffer, nsect, 1, 1)) {
			do_acsi = NULL;
			printk( KERN_ERR "ACSI (write): Timeout in command block\n" );
			bad_rw_intr();
			goto repeat;
		}
		SET_TIMER();
		return;
	}
	if (rq_data_dir(CURRENT) == READ) {
		CMDSET_TARG_LUN( read_cmd, target, lun );
		CMDSET_BLOCK( read_cmd, block );
		CMDSET_LEN( read_cmd, nsect );
		do_acsi = read_intr;
		if (!acsicmd_dma( read_cmd, buffer, nsect, 0, 1)) {
			do_acsi = NULL;
			printk( KERN_ERR "ACSI (read): Timeout in command block\n" );
			bad_rw_intr();
			goto repeat;
		}
		SET_TIMER();
		return;
	}
	panic("unknown ACSI command");
}



/***********************************************************************
 *
 *  Misc functions: ioctl, open, release, check_change, ...
 *
 ***********************************************************************/

static int acsi_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct acsi_info_struct *aip = bdev->bd_disk->private_data;

	/*
	 * Just fake some geometry here, it's nonsense anyway
	 * To make it easy, use Adaptec's usual 64/32 mapping
	 */
	geo->heads = 64;
	geo->sectors = 32;
	geo->cylinders = aip->size >> 11;
	return 0;
}

static int acsi_ioctl( struct inode *inode, struct file *file,
					   unsigned int cmd, unsigned long arg )
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct acsi_info_struct *aip = disk->private_data;
	switch (cmd) {
	  case SCSI_IOCTL_GET_IDLUN:
		/* SCSI compatible GET_IDLUN call to get target's ID and LUN number */
		put_user( aip->target | (aip->lun << 8),
				  &((Scsi_Idlun *) arg)->dev_id );
		put_user( 0, &((Scsi_Idlun *) arg)->host_unique_id );
		return 0;
	  default:
		return -EINVAL;
	}
}


/*
 * Open a device, check for read-only and lock the medium if it is
 * removable.
 *
 * Changes by Martin Rogge, 9th Aug 1995:
 * Check whether check_disk_change (and therefore revalidate_acsidisk)
 * was successful. They fail when there is no medium in the drive.
 *
 * The problem of media being changed during an operation can be 
 * ignored because of the prevent_removal code.
 *
 * Added check for the validity of the device number.
 *
 */

static int acsi_open( struct inode * inode, struct file * filp )
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct acsi_info_struct *aip = disk->private_data;

	if (aip->access_count == 0 && aip->removable) {
#if 0
		aip->changed = 1;	/* safety first */
#endif
		check_disk_change( inode->i_bdev );
		if (aip->changed)	/* revalidate was not successful (no medium) */
			return -ENXIO;
		acsi_prevent_removal(aip, 1);
	}
	aip->access_count++;

	if (filp && filp->f_mode) {
		check_disk_change( inode->i_bdev );
		if (filp->f_mode & 2) {
			if (aip->read_only) {
				acsi_release( inode, filp );
				return -EROFS;
			}
		}
	}

	return 0;
}

/*
 * Releasing a block device means we sync() it, so that it can safely
 * be forgotten about...
 */

static int acsi_release( struct inode * inode, struct file * file )
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct acsi_info_struct *aip = disk->private_data;
	if (--aip->access_count == 0 && aip->removable)
		acsi_prevent_removal(aip, 0);
	return( 0 );
}

/*
 * Prevent or allow a media change for removable devices.
 */

static void acsi_prevent_removal(struct acsi_info_struct *aip, int flag)
{
	stdma_lock( NULL, NULL );
	
	CMDSET_TARG_LUN(pa_med_rem_cmd, aip->target, aip->lun);
	CMDSET_LEN( pa_med_rem_cmd, flag );
	
	if (acsicmd_nodma(pa_med_rem_cmd, 0) && acsi_wait_for_IRQ(3*HZ))
		acsi_getstatus();
	/* Do not report errors -- some devices may not know this command. */

	ENABLE_IRQ();
	stdma_release();
}

static int acsi_media_change(struct gendisk *disk)
{
	struct acsi_info_struct *aip = disk->private_data;

	if (!aip->removable) 
		return 0;

	if (aip->changed)
		/* We can be sure that the medium has been changed -- REQUEST
		 * SENSE has reported this earlier.
		 */
		return 1;

	/* If the flag isn't set, make a test by reading block 0.
	 * If errors happen, it seems to be better to say "changed"...
	 */
	stdma_lock( NULL, NULL );
	CMDSET_TARG_LUN(read_cmd, aip->target, aip->lun);
	CMDSET_BLOCK( read_cmd, 0 );
	CMDSET_LEN( read_cmd, 1 );
	if (acsicmd_dma(read_cmd, acsi_buffer, 1, 0, 0) &&
	    acsi_wait_for_IRQ(3*HZ)) {
		if (acsi_getstatus()) {
			if (acsi_reqsense(acsi_buffer, aip->target, aip->lun)) {
				if (CARTRCH_STAT(aip, acsi_buffer))
					aip->changed = 1;
			}
			else {
				printk( KERN_ERR "%s: REQUEST SENSE failed in test for "
				       "medium change; assuming a change\n", disk->disk_name );
				aip->changed = 1;
			}
		}
	}
	else {
		printk( KERN_ERR "%s: Test for medium changed timed out; "
				"assuming a change\n", disk->disk_name);
		aip->changed = 1;
	}
	ENABLE_IRQ();
	stdma_release();

	/* Now, after reading a block, the changed status is surely valid. */
	return aip->changed;
}


static int acsi_change_blk_size( int target, int lun)

{	int i;

	for (i=0; i<12; i++)
		acsi_buffer[i] = 0;

	acsi_buffer[3] = 8;
	acsi_buffer[10] = 2;
	CMDSET_TARG_LUN( modeselect_cmd, target, lun);

	if (!acsicmd_dma( modeselect_cmd, acsi_buffer, 1,1,0) ||
		!acsi_wait_for_IRQ( 3*HZ ) ||
		acsi_getstatus() != 0 ) {
		return(0);
	}
	return(1);
}


static int acsi_mode_sense( int target, int lun, SENSE_DATA *sd )

{
	int page;

	CMDSET_TARG_LUN( modesense_cmd, target, lun );
	for (page=0; page<4; page++) {
		modesense_cmd[2] = page;
		if (!acsicmd_dma( modesense_cmd, acsi_buffer, 1, 0, 0 ) ||
		    !acsi_wait_for_IRQ( 3*HZ ) ||
		    acsi_getstatus())
			continue;

		/* read twice to jump over the second 16-byte border! */
		udelay(300);
		if (acsi_wait_for_noIRQ( 20 ) &&
		    acsicmd_nodma( modesense_cmd, 0 ) &&
		    acsi_wait_for_IRQ( 3*HZ ) &&
		    acsi_getstatus() == 0)
			break;
	}
	if (page == 4) {
		return(0);
	}

	dma_cache_maintenance( phys_acsi_buffer, sizeof(SENSE_DATA), 0 );
	*sd = *(SENSE_DATA *)acsi_buffer;

	/* Validity check, depending on type of data */
	
	switch( SENSE_TYPE(*sd) ) {

	  case SENSE_TYPE_ATARI:
		if (CAPACITY(*sd) == 0)
			goto invalid_sense;
		break;

	  case SENSE_TYPE_SCSI:
		if (sd->scsi.descriptor_size != 8)
			goto invalid_sense;
		break;

	  case SENSE_TYPE_UNKNOWN:

		printk( KERN_ERR "ACSI target %d, lun %d: Cannot interpret "
				"sense data\n", target, lun ); 
		
	  invalid_sense:

#ifdef DEBUG
		{	int i;
		printk( "Mode sense data for ACSI target %d, lun %d seem not valid:",
				target, lun );
		for( i = 0; i < sizeof(SENSE_DATA); ++i )
			printk( "%02x ", (unsigned char)acsi_buffer[i] );
		printk( "\n" );
		}
#endif
		return( 0 );
	}
		
	return( 1 );
}



/*******************************************************************
 *
 *  Initialization
 *
 ********************************************************************/


extern struct block_device_operations acsi_fops;

static struct gendisk *acsi_gendisk[MAX_DEV];

#define MAX_SCSI_DEVICE_CODE 10

static const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] =
{
 "Direct-Access    ",
 "Sequential-Access",
 "Printer          ",
 "Processor        ",
 "WORM             ",
 "CD-ROM           ",
 "Scanner          ",
 "Optical Device   ",
 "Medium Changer   ",
 "Communications   "
};

static void print_inquiry(unsigned char *data)
{
	int i;

	printk(KERN_INFO "  Vendor: ");
	for (i = 8; i < 16; i++)
		{
	        if (data[i] >= 0x20 && i < data[4] + 5)
			printk("%c", data[i]);
		else
			printk(" ");
		}

	printk("  Model: ");
	for (i = 16; i < 32; i++)
		{
	        if (data[i] >= 0x20 && i < data[4] + 5)
			printk("%c", data[i]);
		else
			printk(" ");
		}

	printk("  Rev: ");
	for (i = 32; i < 36; i++)
		{
	        if (data[i] >= 0x20 && i < data[4] + 5)
			printk("%c", data[i]);
		else
			printk(" ");
		}

	printk("\n");

	i = data[0] & 0x1f;

	printk(KERN_INFO "  Type:   %s ", (i < MAX_SCSI_DEVICE_CODE
									   ? scsi_device_types[i]
									   : "Unknown          "));
	printk("                 ANSI SCSI revision: %02x", data[2] & 0x07);
	if ((data[2] & 0x07) == 1 && (data[3] & 0x0f) == 1)
	  printk(" CCS\n");
	else
	  printk("\n");
}


/* 
 * Changes by Martin Rogge, 9th Aug 1995: 
 * acsi_devinit has been taken out of acsi_geninit, because it needs 
 * to be called from revalidate_acsidisk. The result of request sense 
 * is now checked for DRIVE NOT READY.
 *
 * The structure *aip is only valid when acsi_devinit returns 
 * DEV_SUPPORTED. 
 *
 */
	
#define DEV_NONE	0
#define DEV_UNKNOWN	1
#define DEV_SUPPORTED	2
#define DEV_SLM		3

static int acsi_devinit(struct acsi_info_struct *aip)
{
	int status, got_inquiry;
	SENSE_DATA sense;
	unsigned char reqsense, extsense;

	/*****************************************************************/
	/* Do a TEST UNIT READY command to test the presence of a device */
	/*****************************************************************/

	CMDSET_TARG_LUN(tur_cmd, aip->target, aip->lun);
	if (!acsicmd_nodma(tur_cmd, 0)) {
		/* timed out -> no device here */
#ifdef DEBUG_DETECT
		printk("target %d lun %d: timeout\n", aip->target, aip->lun);
#endif
		return DEV_NONE;
	}
		
	/*************************/
	/* Read the ACSI status. */
	/*************************/

	status = acsi_getstatus();
	if (status) {
		if (status == 0x12) {
			/* The SLM printer should be the only device that
			 * responds with the error code in the status byte. In
			 * correct status bytes, bit 4 is never set.
			 */
			printk( KERN_INFO "Detected SLM printer at id %d lun %d\n",
			       aip->target, aip->lun);
			return DEV_SLM;
		}
		/* ignore CHECK CONDITION, since some devices send a
		   UNIT ATTENTION */
		if ((status & 0x1e) != 0x2) {
#ifdef DEBUG_DETECT
			printk("target %d lun %d: status %d\n",
			       aip->target, aip->lun, status);
#endif
			return DEV_UNKNOWN;
		}
	}

	/*******************************/
	/* Do a REQUEST SENSE command. */
	/*******************************/

	if (!acsi_reqsense(acsi_buffer, aip->target, aip->lun)) {
		printk( KERN_WARNING "acsi_reqsense failed\n");
		acsi_buffer[0] = 0;
		acsi_buffer[2] = UNIT_ATTENTION;
	}
	reqsense = acsi_buffer[0];
	extsense = acsi_buffer[2] & 0xf;
	if (status) {
		if ((reqsense & 0x70) == 0x70) {	/* extended sense */
			if (extsense != UNIT_ATTENTION &&
			    extsense != NOT_READY) {
#ifdef DEBUG_DETECT
				printk("target %d lun %d: extended sense %d\n",
				       aip->target, aip->lun, extsense);
#endif
				return DEV_UNKNOWN;
			}
		}
		else {
			if (reqsense & 0x7f) {
#ifdef DEBUG_DETECT
				printk("target %d lun %d: sense %d\n",
				       aip->target, aip->lun, reqsense);
#endif
				return DEV_UNKNOWN;
			}
		}
	}
	else 
		if (reqsense == 0x4) {	/* SH204 Bug workaround */
#ifdef DEBUG_DETECT
			printk("target %d lun %d status=0 sense=4\n",
			       aip->target, aip->lun);
#endif
			return DEV_UNKNOWN;
		}

	/***********************************************************/
	/* Do an INQUIRY command to get more infos on this device. */
	/***********************************************************/

	/* Assume default values */
	aip->removable = 1;
	aip->read_only = 0;
	aip->old_atari_disk = 0;
	aip->changed = (extsense == NOT_READY);	/* medium inserted? */
	aip->size = DEFAULT_SIZE;
	got_inquiry = 0;
	/* Fake inquiry result for old atari disks */
	memcpy(acsi_buffer, "\000\000\001\000    Adaptec 40xx"
	       "                    ", 40);
	CMDSET_TARG_LUN(inquiry_cmd, aip->target, aip->lun);
	if (acsicmd_dma(inquiry_cmd, acsi_buffer, 1, 0, 0) &&
	    acsi_getstatus() == 0) {
		acsicmd_nodma(inquiry_cmd, 0);
		acsi_getstatus();
		dma_cache_maintenance( phys_acsi_buffer, 256, 0 );
		got_inquiry = 1;
		aip->removable = !!(acsi_buffer[1] & 0x80);
	}
	if (aip->type == NONE)	/* only at boot time */
		print_inquiry(acsi_buffer);
	switch(acsi_buffer[0]) {
	  case TYPE_DISK:
		aip->type = HARDDISK;
		break;
	  case TYPE_ROM:
		aip->type = CDROM;
		aip->read_only = 1;
		break;
	  default:
		return DEV_UNKNOWN;
	}
	/****************************/
	/* Do a MODE SENSE command. */
	/****************************/

	if (!acsi_mode_sense(aip->target, aip->lun, &sense)) {
		printk( KERN_WARNING "No mode sense data.\n" );
		return DEV_UNKNOWN;
	}
	if ((SECTOR_SIZE(sense) != 512) &&
	    ((aip->type != CDROM) ||
	     !acsi_change_blk_size(aip->target, aip->lun) ||
	     !acsi_mode_sense(aip->target, aip->lun, &sense) ||
	     (SECTOR_SIZE(sense) != 512))) {
		printk( KERN_WARNING "Sector size != 512 not supported.\n" );
		return DEV_UNKNOWN;
	}
	/* There are disks out there that claim to have 0 sectors... */
	if (CAPACITY(sense))
		aip->size = CAPACITY(sense);	/* else keep DEFAULT_SIZE */
	if (!got_inquiry && SENSE_TYPE(sense) == SENSE_TYPE_ATARI) {
		/* If INQUIRY failed and the sense data suggest an old
		 * Atari disk (SH20x, Megafile), the disk is not removable
		 */
		aip->removable = 0;
		aip->old_atari_disk = 1;
	}
	
	/******************/
	/* We've done it. */
	/******************/
	
	return DEV_SUPPORTED;
}

EXPORT_SYMBOL(acsi_delay_start);
EXPORT_SYMBOL(acsi_delay_end);
EXPORT_SYMBOL(acsi_wait_for_IRQ);
EXPORT_SYMBOL(acsi_wait_for_noIRQ);
EXPORT_SYMBOL(acsicmd_nodma);
EXPORT_SYMBOL(acsi_getstatus);
EXPORT_SYMBOL(acsi_buffer);
EXPORT_SYMBOL(phys_acsi_buffer);

#ifdef CONFIG_ATARI_SLM_MODULE
void acsi_attach_SLMs( int (*attach_func)( int, int ) );

EXPORT_SYMBOL(acsi_extstatus);
EXPORT_SYMBOL(acsi_end_extstatus);
EXPORT_SYMBOL(acsi_extcmd);
EXPORT_SYMBOL(acsi_attach_SLMs);

/* to remember IDs of SLM devices, SLM module is loaded later
 * (index is target#, contents is lun#, -1 means "no SLM") */
int SLM_devices[8];
#endif

static struct block_device_operations acsi_fops = {
	.owner		= THIS_MODULE,
	.open		= acsi_open,
	.release	= acsi_release,
	.ioctl		= acsi_ioctl,
	.getgeo		= acsi_getgeo,
	.media_changed	= acsi_media_change,
	.revalidate_disk= acsi_revalidate,
};

#ifdef CONFIG_ATARI_SLM_MODULE
/* call attach_slm() for each device that is a printer; needed for init of SLM
 * driver as a module, since it's not yet present if acsi.c is inited and thus
 * the bus gets scanned. */
void acsi_attach_SLMs( int (*attach_func)( int, int ) )
{
	int i, n = 0;

	for( i = 0; i < 8; ++i )
		if (SLM_devices[i] >= 0)
			n += (*attach_func)( i, SLM_devices[i] );
	printk( KERN_INFO "Found %d SLM printer(s) total.\n", n );
}
#endif /* CONFIG_ATARI_SLM_MODULE */


int acsi_init( void )
{
	int err = 0;
	int i, target, lun;
	struct acsi_info_struct *aip;
#ifdef CONFIG_ATARI_SLM
	int n_slm = 0;
#endif
	if (!MACH_IS_ATARI || !ATARIHW_PRESENT(ACSI))
		return 0;
	if (register_blkdev(ACSI_MAJOR, "ad")) {
		err = -EBUSY;
		goto out1;
	}
	if (!(acsi_buffer =
		  (char *)atari_stram_alloc(ACSI_BUFFER_SIZE, "acsi"))) {
		err = -ENOMEM;
		printk( KERN_ERR "Unable to get ACSI ST-Ram buffer.\n" );
		goto out2;
	}
	phys_acsi_buffer = virt_to_phys( acsi_buffer );
	STramMask = ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 : 0xff000000;
	
	acsi_queue = blk_init_queue(do_acsi_request, &acsi_lock);
	if (!acsi_queue) {
		err = -ENOMEM;
		goto out2a;
	}
#ifdef CONFIG_ATARI_SLM
	err = slm_init();
#endif
	if (err)
		goto out3;

	printk( KERN_INFO "Probing ACSI devices:\n" );
	NDevices = 0;
#ifdef CONFIG_ATARI_SLM_MODULE
	for( i = 0; i < 8; ++i )
		SLM_devices[i] = -1;
#endif
	stdma_lock(NULL, NULL);

	for (target = 0; target < 8 && NDevices < MAX_DEV; ++target) {
		lun = 0;
		do {
			aip = &acsi_info[NDevices];
			aip->type = NONE;
			aip->target = target;
			aip->lun = lun;
			i = acsi_devinit(aip);
			switch (i) {
			  case DEV_SUPPORTED:
				printk( KERN_INFO "Detected ");
				switch (aip->type) {
				  case HARDDISK:
					printk("disk");
					break;
				  case CDROM:
					printk("cdrom");
					break;
				  default:
				}
				printk(" ad%c at id %d lun %d ",
				       'a' + NDevices, target, lun);
				if (aip->removable) 
					printk("(removable) ");
				if (aip->read_only) 
					printk("(read-only) ");
				if (aip->size == DEFAULT_SIZE)
					printk(" unkown size, using default ");
				printk("%ld MByte\n",
				       (aip->size*512+1024*1024/2)/(1024*1024));
				NDevices++;
				break;
			  case DEV_SLM:
#ifdef CONFIG_ATARI_SLM
				n_slm += attach_slm( target, lun );
				break;
#endif
#ifdef CONFIG_ATARI_SLM_MODULE
				SLM_devices[target] = lun;
				break;
#endif
				/* neither of the above: fall through to unknown device */
			  case DEV_UNKNOWN:
				printk( KERN_INFO "Detected unsupported device at "
						"id %d lun %d\n", target, lun);
				break;
			}
		}
#ifdef CONFIG_ACSI_MULTI_LUN
		while (i != DEV_NONE && ++lun < MAX_LUN);
#else
		while (0);
#endif
	}

	/* reenable interrupt */
	ENABLE_IRQ();
	stdma_release();

#ifndef CONFIG_ATARI_SLM
	printk( KERN_INFO "Found %d ACSI device(s) total.\n", NDevices );
#else
	printk( KERN_INFO "Found %d ACSI device(s) and %d SLM printer(s) total.\n",
			NDevices, n_slm );
#endif
	err = -ENOMEM;
	for( i = 0; i < NDevices; ++i ) {
		acsi_gendisk[i] = alloc_disk(16);
		if (!acsi_gendisk[i])
			goto out4;
	}

	for( i = 0; i < NDevices; ++i ) {
		struct gendisk *disk = acsi_gendisk[i];
		sprintf(disk->disk_name, "ad%c", 'a'+i);
		aip = &acsi_info[NDevices];
		disk->major = ACSI_MAJOR;
		disk->first_minor = i << 4;
		if (acsi_info[i].type != HARDDISK)
			disk->minors = 1;
		disk->fops = &acsi_fops;
		disk->private_data = &acsi_info[i];
		set_capacity(disk, acsi_info[i].size);
		disk->queue = acsi_queue;
		add_disk(disk);
	}
	return 0;
out4:
	while (i--)
		put_disk(acsi_gendisk[i]);
out3:
	blk_cleanup_queue(acsi_queue);
out2a:
	atari_stram_free( acsi_buffer );
out2:
	unregister_blkdev( ACSI_MAJOR, "ad" );
out1:
	return err;
}


#ifdef MODULE

MODULE_LICENSE("GPL");

int init_module(void)
{
	int err;

	if ((err = acsi_init()))
		return( err );
	printk( KERN_INFO "ACSI driver loaded as module.\n");
	return( 0 );
}

void cleanup_module(void)
{
	int i;
	del_timer( &acsi_timer );
	blk_cleanup_queue(acsi_queue);
	atari_stram_free( acsi_buffer );

	if (unregister_blkdev( ACSI_MAJOR, "ad" ) != 0)
		printk( KERN_ERR "acsi: cleanup_module failed\n");

	for (i = 0; i < NDevices; i++) {
		del_gendisk(acsi_gendisk[i]);
		put_disk(acsi_gendisk[i]);
	}
}
#endif

/*
 * This routine is called to flush all partitions and partition tables
 * for a changed scsi disk, and then re-read the new partition table.
 * If we are revalidating a disk because of a media change, then we
 * enter with usage == 0.  If we are using an ioctl, we automatically have
 * usage == 1 (we need an open channel to use an ioctl :-), so this
 * is our limit.
 *
 * Changes by Martin Rogge, 9th Aug 1995: 
 * got cd-roms to work by calling acsi_devinit. There are only two problems:
 * First, if there is no medium inserted, the status will remain "changed".
 * That is no problem at all, but our design of three-valued logic (medium
 * changed, medium not changed, no medium inserted).
 * Secondly the check could fail completely and the drive could deliver
 * nonsensical data, which could mess up the acsi_info[] structure. In
 * that case we try to make the entry safe.
 *
 */

static int acsi_revalidate(struct gendisk *disk)
{
	struct acsi_info_struct *aip = disk->private_data;
	stdma_lock( NULL, NULL );
	if (acsi_devinit(aip) != DEV_SUPPORTED) {
		printk( KERN_ERR "ACSI: revalidate failed for target %d lun %d\n",
		       aip->target, aip->lun);
		aip->size = 0;
		aip->read_only = 1;
		aip->removable = 1;
		aip->changed = 1; /* next acsi_open will try again... */
	}

	ENABLE_IRQ();
	stdma_release();
	set_capacity(disk, aip->size);
	return 0;
}