ataflop.c

Linux块设备驱动源码

		local_irq_restore(flags);
		DPRINT(("fd_readtrack_check(): done\n"));
		FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
		udelay(25);

		/* No error until now -- the FDC would have interrupted
		 * otherwise!
		 */
		fd_rwsec_done1(0);
	}
	else {
		/* not yet finished, wait another tenth rotation */
		local_irq_restore(flags);
		DPRINT(("fd_readtrack_check(): not yet finished\n"));
		mod_timer(&readtrack_timer, jiffies + HZ/5/10);
	}
}


static void fd_rwsec_done( int status )
{
	DPRINT(("fd_rwsec_done()\n"));

	if (read_track) {
		del_timer(&readtrack_timer);
		if (!MultReadInProgress)
			return;
		MultReadInProgress = 0;
	}
	fd_rwsec_done1(status);
}

static void fd_rwsec_done1(int status)
{
	unsigned int track;

	stop_timeout();
	
	/* Correct the track if stretch != 0 */
	if (SUDT->stretch) {
		track = FDC_READ( FDCREG_TRACK);
		MFPDELAY();
		FDC_WRITE( FDCREG_TRACK, track << SUDT->stretch);
	}

	if (!UseTrackbuffer) {
		dma_wd.dma_mode_status = 0x90;
		MFPDELAY();
		if (!(dma_wd.dma_mode_status & 0x01)) {
			printk(KERN_ERR "fd%d: DMA error\n", SelectedDrive );
			goto err_end;
		}
	}
	MFPDELAY();

	if (ReqCmd == WRITE && (status & FDCSTAT_WPROT)) {
		printk(KERN_NOTICE "fd%d: is write protected\n", SelectedDrive );
		goto err_end;
	}	
	if ((status & FDCSTAT_RECNF) &&
	    /* RECNF is no error after a multiple read when the FDC
	       searched for a non-existent sector! */
	    !(read_track && FDC_READ(FDCREG_SECTOR) > SUDT->spt)) {
		if (Probing) {
			if (SUDT > disk_type) {
			    if (SUDT[-1].blocks > ReqBlock) {
				/* try another disk type */
				SUDT--;
				set_capacity(unit[SelectedDrive].disk,
							SUDT->blocks);
			    } else
				Probing = 0;
			}
			else {
				if (SUD.flags & FTD_MSG)
					printk(KERN_INFO "fd%d: Auto-detected floppy type %s\n",
					       SelectedDrive, SUDT->name );
				Probing=0;
			}
		} else {	
/* record not found, but not probing. Maybe stretch wrong ? Restart probing */
			if (SUD.autoprobe) {
				SUDT = disk_type + StartDiskType[DriveType];
				set_capacity(unit[SelectedDrive].disk,
							SUDT->blocks);
				Probing = 1;
			}
		}
		if (Probing) {
			if (ATARIHW_PRESENT(FDCSPEED)) {
				dma_wd.fdc_speed = SUDT->fdc_speed;
				MFPDELAY();
			}
			setup_req_params( SelectedDrive );
			BufferDrive = -1;
			do_fd_action( SelectedDrive );
			return;
		}

		printk(KERN_ERR "fd%d: sector %d not found (side %d, track %d)\n",
		       SelectedDrive, FDC_READ (FDCREG_SECTOR), ReqSide, ReqTrack );
		goto err_end;
	}
	if (status & FDCSTAT_CRC) {
		printk(KERN_ERR "fd%d: CRC error (side %d, track %d, sector %d)\n",
		       SelectedDrive, ReqSide, ReqTrack, FDC_READ (FDCREG_SECTOR) );
		goto err_end;
	}
	if (status & FDCSTAT_LOST) {
		printk(KERN_ERR "fd%d: lost data (side %d, track %d, sector %d)\n",
		       SelectedDrive, ReqSide, ReqTrack, FDC_READ (FDCREG_SECTOR) );
		goto err_end;
	}

	Probing = 0;
	
	if (ReqCmd == READ) {
		if (!read_track) {
			void *addr;
			addr = ATARIHW_PRESENT( EXTD_DMA ) ? ReqData : DMABuffer;
			dma_cache_maintenance( virt_to_phys(addr), 512, 0 );
			if (!ATARIHW_PRESENT( EXTD_DMA ))
				copy_buffer (addr, ReqData);
		} else {
			dma_cache_maintenance( PhysTrackBuffer, MaxSectors[DriveType] * 512, 0 );
			BufferDrive = SelectedDrive;
			BufferSide  = ReqSide;
			BufferTrack = ReqTrack;
			copy_buffer (SECTOR_BUFFER (ReqSector), ReqData);
		}
	}
  
	if (++ReqCnt < CURRENT->current_nr_sectors) {
		/* read next sector */
		setup_req_params( SelectedDrive );
		do_fd_action( SelectedDrive );
	}
	else {
		/* all sectors finished */
		CURRENT->nr_sectors -= CURRENT->current_nr_sectors;
		CURRENT->sector += CURRENT->current_nr_sectors;
		end_request(CURRENT, 1);
		redo_fd_request();
	}
	return;
  
  err_end:
	BufferDrive = -1;
	fd_error();
}


static void fd_writetrack( void )
{
	unsigned long paddr, flags;
	unsigned int track;
	
	DPRINT(("fd_writetrack() Tr=%d Si=%d\n", ReqTrack, ReqSide ));

	paddr = PhysTrackBuffer;
	dma_cache_maintenance( paddr, BUFFER_SIZE, 1 );

	fd_select_side( ReqSide );
  
	/* Cheat for track if stretch != 0 */
	if (SUDT->stretch) {
		track = FDC_READ( FDCREG_TRACK);
		MFPDELAY();
		FDC_WRITE(FDCREG_TRACK,track >> SUDT->stretch);
	}
	udelay(40);
  
	/* Setup DMA */
	local_irq_save(flags);
	dma_wd.dma_lo = (unsigned char)paddr;
	MFPDELAY();
	paddr >>= 8;
	dma_wd.dma_md = (unsigned char)paddr;
	MFPDELAY();
	paddr >>= 8;
	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);
  
	/* Clear FIFO and switch DMA to correct mode */  
	dma_wd.dma_mode_status = 0x190;  
	MFPDELAY();
	dma_wd.dma_mode_status = 0x90;  
	MFPDELAY();
	dma_wd.dma_mode_status = 0x190;
	MFPDELAY();
  
	/* How many sectors for DMA */
	dma_wd.fdc_acces_seccount = BUFFER_SIZE/512;
	udelay(40);  
  
	/* Start operation */
	dma_wd.dma_mode_status = FDCSELREG_STP | 0x100;
	udelay(40);
	SET_IRQ_HANDLER( fd_writetrack_done );
	dma_wd.fdc_acces_seccount = FDCCMD_WRTRA | get_head_settle_flag(); 

	MotorOn = 1;
	start_timeout();
	/* wait for interrupt */
}


static void fd_writetrack_done( int status )
{
	DPRINT(("fd_writetrack_done()\n"));

	stop_timeout();

	if (status & FDCSTAT_WPROT) {
		printk(KERN_NOTICE "fd%d: is write protected\n", SelectedDrive );
		goto err_end;
	}	
	if (status & FDCSTAT_LOST) {
		printk(KERN_ERR "fd%d: lost data (side %d, track %d)\n",
				SelectedDrive, ReqSide, ReqTrack );
		goto err_end;
	}

	wake_up( &format_wait );
	return;

  err_end:
	fd_error();
}

static void fd_times_out( unsigned long dummy )
{
	atari_disable_irq( IRQ_MFP_FDC );
	if (!FloppyIRQHandler) goto end; /* int occurred after timer was fired, but
					  * before we came here... */

	SET_IRQ_HANDLER( NULL );
	/* If the timeout occurred while the readtrack_check timer was
	 * active, we need to cancel it, else bad things will happen */
	if (UseTrackbuffer)
		del_timer( &readtrack_timer );
	FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
	udelay( 25 );
	
	printk(KERN_ERR "floppy timeout\n" );
	fd_error();
  end:
	atari_enable_irq( IRQ_MFP_FDC );
}


/* The (noop) seek operation here is needed to make the WP bit in the
 * FDC status register accessible for check_change. If the last disk
 * operation would have been a RDSEC, this bit would always read as 0
 * no matter what :-( To save time, the seek goes to the track we're
 * already on.
 */

static void finish_fdc( void )
{
	if (!NeedSeek) {
		finish_fdc_done( 0 );
	}
	else {
		DPRINT(("finish_fdc: dummy seek started\n"));
		FDC_WRITE (FDCREG_DATA, SUD.track);
		SET_IRQ_HANDLER( finish_fdc_done );
		FDC_WRITE (FDCREG_CMD, FDCCMD_SEEK);
		MotorOn = 1;
		start_timeout();
		/* we must wait for the IRQ here, because the ST-DMA
		   is released immediately afterwards and the interrupt
		   may be delivered to the wrong driver. */
	  }
}


static void finish_fdc_done( int dummy )
{
	unsigned long flags;

	DPRINT(("finish_fdc_done entered\n"));
	stop_timeout();
	NeedSeek = 0;

	if (timer_pending(&fd_timer) && time_before(fd_timer.expires, jiffies + 5))
		/* If the check for a disk change is done too early after this
		 * last seek command, the WP bit still reads wrong :-((
		 */
		mod_timer(&fd_timer, jiffies + 5);
	else
		start_check_change_timer();
	start_motor_off_timer();

	local_irq_save(flags);
	stdma_release();
	fdc_busy = 0;
	wake_up( &fdc_wait );
	local_irq_restore(flags);

	DPRINT(("finish_fdc() finished\n"));
}

/* The detection of disk changes is a dark chapter in Atari history :-(
 * Because the "Drive ready" signal isn't present in the Atari
 * hardware, one has to rely on the "Write Protect". This works fine,
 * as long as no write protected disks are used. TOS solves this
 * problem by introducing tri-state logic ("maybe changed") and
 * looking at the serial number in block 0. This isn't possible for
 * Linux, since the floppy driver can't make assumptions about the
 * filesystem used on the disk and thus the contents of block 0. I've
 * chosen the method to always say "The disk was changed" if it is
 * unsure whether it was. This implies that every open or mount
 * invalidates the disk buffers if you work with write protected
 * disks. But at least this is better than working with incorrect data
 * due to unrecognised disk changes.
 */

static int check_floppy_change(struct gendisk *disk)
{
	struct atari_floppy_struct *p = disk->private_data;
	unsigned int drive = p - unit;
	if (test_bit (drive, &fake_change)) {
		/* simulated change (e.g. after formatting) */
		return 1;
	}
	if (test_bit (drive, &changed_floppies)) {
		/* surely changed (the WP signal changed at least once) */
		return 1;
	}
	if (UD.wpstat) {
		/* WP is on -> could be changed: to be sure, buffers should be
		 * invalidated...
		 */
		return 1;
	}

	return 0;
}

static int floppy_revalidate(struct gendisk *disk)
{
	struct atari_floppy_struct *p = disk->private_data;
	unsigned int drive = p - unit;

	if (test_bit(drive, &changed_floppies) ||
	    test_bit(drive, &fake_change) ||
	    p->disktype == 0) {
		if (UD.flags & FTD_MSG)
			printk(KERN_ERR "floppy: clear format %p!\n", UDT);
		BufferDrive = -1;
		clear_bit(drive, &fake_change);
		clear_bit(drive, &changed_floppies);
		/* MSch: clearing geometry makes sense only for autoprobe
		   formats, for 'permanent user-defined' parameter:
		   restore default_params[] here if flagged valid! */
		if (default_params[drive].blocks == 0)
			UDT = 0;
		else
			UDT = &default_params[drive];
	}
	return 0;
}


/* This sets up the global variables describing the current request. */

static void setup_req_params( int drive )
{
	int block = ReqBlock + ReqCnt;

	ReqTrack = block / UDT->spt;
	ReqSector = block - ReqTrack * UDT->spt + 1;
	ReqSide = ReqTrack & 1;
	ReqTrack >>= 1;
	ReqData = ReqBuffer + 512 * ReqCnt;

	if (UseTrackbuffer)
		read_track = (ReqCmd == READ && CURRENT->errors == 0);
	else
		read_track = 0;

	DPRINT(("Request params: Si=%d Tr=%d Se=%d Data=%08lx\n",ReqSide,
			ReqTrack, ReqSector, (unsigned long)ReqData ));
}


static void redo_fd_request(void)
{
	int drive, type;
	struct atari_floppy_struct *floppy;

	DPRINT(("redo_fd_request: CURRENT=%p dev=%s CURRENT->sector=%ld\n",
		CURRENT, CURRENT ? CURRENT->rq_disk->disk_name : "",
		CURRENT ? CURRENT->sector : 0 ));

	IsFormatting = 0;

repeat:

	if (!CURRENT)
		goto the_end;

	floppy = CURRENT->rq_disk->private_data;
	drive = floppy - unit;
	type = floppy->type;
	
	if (!UD.connected) {
		/* drive not connected */
		printk(KERN_ERR "Unknown Device: fd%d\n", drive );
		end_request(CURRENT, 0);
		goto repeat;
	}
		
	if (type == 0) {
		if (!UDT) {
			Probing = 1;
			UDT = disk_type + StartDiskType[DriveType];
			set_capacity(floppy->disk, UDT->blocks);
			UD.autoprobe = 1;
		}
	} 
	else {
		/* user supplied disk type */
		if (--type >= NUM_DISK_MINORS) {
			printk(KERN_WARNING "fd%d: invalid disk format", drive );
			end_request(CURRENT, 0);
			goto repeat;
		}
		if (minor2disktype[type].drive_types > DriveType)  {
			printk(KERN_WARNING "fd%d: unsupported disk format", drive );
			end_request(CURRENT, 0);
			goto repeat;
		}
		type = minor2disktype[type].index;
		UDT = &disk_type[type];
		set_capacity(floppy->disk, UDT->blocks);
		UD.autoprobe = 0;
	}
	
	if (CURRENT->sector + 1 > UDT->blocks) {
		end_request(CURRENT, 0);
		goto repeat;
	}

	/* stop deselect timer */
	del_timer( &motor_off_timer );
		
	ReqCnt = 0;
	ReqCmd = rq_data_dir(CURRENT);
	ReqBlock = CURRENT->sector;
	ReqBuffer = CURRENT->buffer;
	setup_req_params( drive );
	do_fd_action( drive );

	return;

  the_end:
	finish_fdc();
}


void do_fd_request(request_queue_t * q)
{
 	unsigned long flags;

	DPRINT(("do_fd_request for pid %d\n",current->pid));
	while( fdc_busy ) sleep_on( &fdc_wait );
	fdc_busy = 1;
	stdma_lock(floppy_irq, NULL);

	atari_disable_irq( IRQ_MFP_FDC );
	local_save_flags(flags);	/* The request function is called with ints
	local_irq_disable();		 * disabled... so must save the IPL for later */ 
	redo_fd_request();
	local_irq_restore(flags);
	atari_enable_irq( IRQ_MFP_FDC );
}

static int fd_ioctl(struct inode *inode, struct file *filp,
		    unsigned int cmd, unsigned long param)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct atari_floppy_struct *floppy = disk->private_data;
	int drive = floppy - unit;
	int type = floppy->type;
	struct atari_format_descr fmt_desc;
	struct atari_disk_type *dtp;
	struct floppy_struct getprm;
	int settype;
	struct floppy_struct setprm;

	switch (cmd) {
	case FDGETPRM:
		if (type) {
			if (--type >= NUM_DISK_MINORS)
				return -ENODEV;