acsi.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

		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 = {
	open:			acsi_open,
	release:		acsi_release,
	ioctl:			acsi_ioctl,
	check_media_change:	acsi_media_change,
	revalidate:		acsi_revalidate,
};

static void acsi_geninit(void)
{
	int i, target, lun;
	struct acsi_info_struct *aip;
#ifdef CONFIG_ATARI_SLM
	int n_slm = 0;
#endif

	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
					 
	for( i = 0; i < (MAX_DEV << 4); i++ )
		acsi_blocksizes[i] = 1024;
	blksize_size[MAJOR_NR] = acsi_blocksizes;
	for( i = 0; i < NDevices; ++i )
		register_disk(&acsi_gendisk, MKDEV(MAJOR_NR,i<<4),
				(acsi_info[i].type==HARDDISK)?1<<4:1,
				&acsi_fops,
				acsi_info[i].size);
	acsi_gendisk.nr_real = NDevices;
}

#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;
	if (!MACH_IS_ATARI || !ATARIHW_PRESENT(ACSI))
		return 0;
	if (devfs_register_blkdev( MAJOR_NR, "ad", &acsi_fops )) {
		printk( KERN_ERR "Unable to get major %d for ACSI\n", MAJOR_NR );
		return -EBUSY;
	}
	if (!(acsi_buffer =
		  (char *)atari_stram_alloc(ACSI_BUFFER_SIZE, "acsi"))) {
		printk( KERN_ERR "Unable to get ACSI ST-Ram buffer.\n" );
		devfs_unregister_blkdev( MAJOR_NR, "ad" );
		return -ENOMEM;
	}
	phys_acsi_buffer = virt_to_phys( acsi_buffer );
	STramMask = ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 : 0xff000000;
	
	blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
	read_ahead[MAJOR_NR] = 8;		/* 8 sector (4kB) read-ahead */
	acsi_gendisk.next = gendisk_head;
	gendisk_head = &acsi_gendisk;

#ifdef CONFIG_ATARI_SLM
	err = slm_init();
#endif
	if (!err)
		acsi_geninit();
	return err;
}


#ifdef MODULE
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)
{
	struct gendisk ** gdp;

	del_timer( &acsi_timer );
	blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
	atari_stram_free( acsi_buffer );

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

	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
		if (*gdp == &acsi_gendisk)
			break;
	if (!*gdp)
		printk( KERN_ERR "acsi: entry in disk chain missing!\n" );
	else
		*gdp = (*gdp)->next;
}
#endif

#define DEVICE_BUSY busy[device]
#define USAGE access_count[device]
#define GENDISK_STRUCT acsi_gendisk

/*
 * 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 revalidate_acsidisk( int dev, int maxusage )
{
	int device;
	struct gendisk * gdev;
	int max_p, start, i;
	struct acsi_info_struct *aip;
	
	device = DEVICE_NR(MINOR(dev));
	aip = &acsi_info[device];
	gdev = &GENDISK_STRUCT;

	cli();
	if (DEVICE_BUSY || USAGE > maxusage) {
		sti();
		return -EBUSY;
	};
	DEVICE_BUSY = 1;
	sti();

	max_p = gdev->max_p;
	start = device << gdev->minor_shift;

	for( i = max_p - 1; i >= 0 ; i-- ) {
		if (gdev->part[start + i].nr_sects != 0) {
			kdev_t devp = MKDEV(MAJOR_NR, start + i);
			struct super_block *sb = get_super(devp);

			fsync_dev(devp);
			if (sb)
				invalidate_inodes(sb);
			invalidate_buffers(devp);
			gdev->part[start + i].nr_sects = 0;
		}
		gdev->part[start+i].start_sect = 0;
	};

	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();
	
	grok_partitions(gdev, device, (aip->type==HARDDISK)?1<<4:1, aip->size);

	DEVICE_BUSY = 0;
	wake_up(&busy_wait);
	return 0;
}


static int acsi_revalidate (dev_t dev)
{
  return revalidate_acsidisk (dev, 0);
}