text: #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/kernel.h>
  #include <linux/timer.h>
  #include <linux/mm.h>
  #include <linux/interrupt.h>
  #include <linux/major.h>
  #include <linux/errno.h>
  #include <linux/genhd.h>
  #include <linux/blkpg.h>
  #include <linux/slab.h>
  #include <linux/pci.h>
  #include <linux/delay.h>
  #include <linux/hdreg.h>
  #include <linux/ide.h>
  #include <linux/bitops.h>
  
  #include <asm/byteorder.h>
  #include <asm/irq.h>
  #include <asm/uaccess.h>
  #include <asm/io.h>
  
  /*
   *	IDE library routines. These are plug in code that most 
   *	drivers can use but occasionally may be weird enough
   *	to want to do their own thing with
   *
   *	Add common non I/O op stuff here. Make sure it has proper
   *	kernel-doc function headers or your patch will be rejected
   */
  
  static const char *udma_str[] =
  	 { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
  	   "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
  static const char *mwdma_str[] =
  	{ "MWDMA0", "MWDMA1", "MWDMA2" };
  static const char *swdma_str[] =
  	{ "SWDMA0", "SWDMA1", "SWDMA2" };
  static const char *pio_str[] =
  	{ "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" };
  
  /**
   *	ide_xfer_verbose	-	return IDE mode names
   *	@mode: transfer mode
   *
   *	Returns a constant string giving the name of the mode
   *	requested.
   */
  
  const char *ide_xfer_verbose(u8 mode)
  {
  	const char *s;
  	u8 i = mode & 0xf;
  
  	if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
  		s = udma_str[i];
  	else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2)
  		s = mwdma_str[i];
  	else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
  		s = swdma_str[i];
  	else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5)
  		s = pio_str[i & 0x7];
  	else if (mode == XFER_PIO_SLOW)
  		s = "PIO SLOW";
  	else
  		s = "XFER ERROR";
  
  	return s;
  }
  
  EXPORT_SYMBOL(ide_xfer_verbose);
  
  /**
   *	ide_rate_filter		-	filter transfer mode
   *	@drive: IDE device
   *	@speed: desired speed
   *
   *	Given the available transfer modes this function returns
   *	the best available speed at or below the speed requested.
   *
   *	TODO: check device PIO capabilities
   */
  
  static u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	u8 mode = ide_find_dma_mode(drive, speed);
  
  	if (mode == 0) {
  		if (hwif->pio_mask)
  			mode = fls(hwif->pio_mask) - 1 + XFER_PIO_0;
  		else
  			mode = XFER_PIO_4;
  	}
  
  //	printk("%s: mode 0x%02x, speed 0x%02x\n", __FUNCTION__, mode, speed);
  
  	return min(speed, mode);
  }
  
  /*
   * Standard (generic) timings for PIO modes, from ATA2 specification.
   * These timings are for access to the IDE data port register *only*.
   * Some drives may specify a mode, while also specifying a different
   * value for cycle_time (from drive identification data).
   */
  const ide_pio_timings_t ide_pio_timings[6] = {
  	{ 70,	165,	600 },	/* PIO Mode 0 */
  	{ 50,	125,	383 },	/* PIO Mode 1 */
  	{ 30,	100,	240 },	/* PIO Mode 2 */
  	{ 30,	80,	180 },	/* PIO Mode 3 with IORDY */
  	{ 25,	70,	120 },	/* PIO Mode 4 with IORDY */
  	{ 20,	50,	100 }	/* PIO Mode 5 with IORDY (nonstandard) */
  };
  
  EXPORT_SYMBOL_GPL(ide_pio_timings);
  
  /*
   * Shared data/functions for determining best PIO mode for an IDE drive.
   * Most of this stuff originally lived in cmd640.c, and changes to the
   * ide_pio_blacklist[] table should be made with EXTREME CAUTION to avoid
   * breaking the fragile cmd640.c support.
   */
  
  /*
   * Black list. Some drives incorrectly report their maximal PIO mode,
   * at least in respect to CMD640. Here we keep info on some known drives.
   */
  static struct ide_pio_info {
  	const char	*name;
  	int		pio;
  } ide_pio_blacklist [] = {
  /*	{ "Conner Peripherals 1275MB - CFS1275A", 4 }, */
  	{ "Conner Peripherals 540MB - CFS540A", 3 },
  
  	{ "WDC AC2700",  3 },
  	{ "WDC AC2540",  3 },
  	{ "WDC AC2420",  3 },
  	{ "WDC AC2340",  3 },
  	{ "WDC AC2250",  0 },
  	{ "WDC AC2200",  0 },
  	{ "WDC AC21200", 4 },
  	{ "WDC AC2120",  0 },
  	{ "WDC AC2850",  3 },
  	{ "WDC AC1270",  3 },
  	{ "WDC AC1170",  1 },
  	{ "WDC AC1210",  1 },
  	{ "WDC AC280",   0 },
  /*	{ "WDC AC21000", 4 }, */
  	{ "WDC AC31000", 3 },
  	{ "WDC AC31200", 3 },
  /*	{ "WDC AC31600", 4 }, */
  
  	{ "Maxtor 7131 AT", 1 },
  	{ "Maxtor 7171 AT", 1 },
  	{ "Maxtor 7213 AT", 1 },
  	{ "Maxtor 7245 AT", 1 },
  	{ "Maxtor 7345 AT", 1 },
  	{ "Maxtor 7546 AT", 3 },
  	{ "Maxtor 7540 AV", 3 },
  
  	{ "SAMSUNG SHD-3121A", 1 },
  	{ "SAMSUNG SHD-3122A", 1 },
  	{ "SAMSUNG SHD-3172A", 1 },
  
  /*	{ "ST51080A", 4 },
   *	{ "ST51270A", 4 },
   *	{ "ST31220A", 4 },
   *	{ "ST31640A", 4 },
   *	{ "ST32140A", 4 },
   *	{ "ST3780A",  4 },
   */
  	{ "ST5660A",  3 },
  	{ "ST3660A",  3 },
  	{ "ST3630A",  3 },
  	{ "ST3655A",  3 },
  	{ "ST3391A",  3 },
  	{ "ST3390A",  1 },
  	{ "ST3600A",  1 },
  	{ "ST3290A",  0 },
  	{ "ST3144A",  0 },
  	{ "ST3491A",  1 },	/* reports 3, should be 1 or 2 (depending on */	
  				/* drive) according to Seagates FIND-ATA program */
  
  	{ "QUANTUM ELS127A", 0 },
  	{ "QUANTUM ELS170A", 0 },
  	{ "QUANTUM LPS240A", 0 },
  	{ "QUANTUM LPS210A", 3 },
  	{ "QUANTUM LPS270A", 3 },
  	{ "QUANTUM LPS365A", 3 },
  	{ "QUANTUM LPS540A", 3 },
  	{ "QUANTUM LIGHTNING 540A", 3 },
  	{ "QUANTUM LIGHTNING 730A", 3 },
  
          { "QUANTUM FIREBALL_540", 3 }, /* Older Quantum Fireballs don't work */
          { "QUANTUM FIREBALL_640", 3 }, 
          { "QUANTUM FIREBALL_1080", 3 },
          { "QUANTUM FIREBALL_1280", 3 },
  	{ NULL,	0 }
  };
  
  /**
   *	ide_scan_pio_blacklist 	-	check for a blacklisted drive
   *	@model: Drive model string
   *
   *	This routine searches the ide_pio_blacklist for an entry
   *	matching the start/whole of the supplied model name.
   *
   *	Returns -1 if no match found.
   *	Otherwise returns the recommended PIO mode from ide_pio_blacklist[].
   */
  
  static int ide_scan_pio_blacklist (char *model)
  {
  	struct ide_pio_info *p;
  
  	for (p = ide_pio_blacklist; p->name != NULL; p++) {
  		if (strncmp(p->name, model, strlen(p->name)) == 0)
  			return p->pio;
  	}
  	return -1;
  }
  
  unsigned int ide_pio_cycle_time(ide_drive_t *drive, u8 pio)
  {
  	struct hd_driveid *id = drive->id;
  	int cycle_time = 0;
  
  	if (id->field_valid & 2) {
  		if (id->capability & 8)
  			cycle_time = id->eide_pio_iordy;
  		else
  			cycle_time = id->eide_pio;
  	}
  
  	/* conservative "downgrade" for all pre-ATA2 drives */
  	if (pio < 3) {
  		if (cycle_time && cycle_time < ide_pio_timings[pio].cycle_time)
  			cycle_time = 0; /* use standard timing */
  	}
  
  	return cycle_time ? cycle_time : ide_pio_timings[pio].cycle_time;
  }
  
  EXPORT_SYMBOL_GPL(ide_pio_cycle_time);
  
  /**
   *	ide_get_best_pio_mode	-	get PIO mode from drive
   *	@drive: drive to consider
   *	@mode_wanted: preferred mode
   *	@max_mode: highest allowed mode
   *
   *	This routine returns the recommended PIO settings for a given drive,
   *	based on the drive->id information and the ide_pio_blacklist[].
   *
   *	Drive PIO mode is auto-selected if 255 is passed as mode_wanted.
   *	This is used by most chipset support modules when "auto-tuning".
   */
  
  u8 ide_get_best_pio_mode (ide_drive_t *drive, u8 mode_wanted, u8 max_mode)
  {
  	int pio_mode;
  	struct hd_driveid* id = drive->id;
  	int overridden  = 0;
  
  	if (mode_wanted != 255)
  		return min_t(u8, mode_wanted, max_mode);
  
  	if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_BLACKLIST) == 0 &&
  	    (pio_mode = ide_scan_pio_blacklist(id->model)) != -1) {
  		printk(KERN_INFO "%s: is on PIO blacklist\n", drive->name);
  	} else {
  		pio_mode = id->tPIO;
  		if (pio_mode > 2) {	/* 2 is maximum allowed tPIO value */
  			pio_mode = 2;
  			overridden = 1;
  		}
  		if (id->field_valid & 2) {	  /* drive implements ATA2? */
  			if (id->capability & 8) { /* IORDY supported? */
  				if (id->eide_pio_modes & 7) {
  					overridden = 0;
  					if (id->eide_pio_modes & 4)
  						pio_mode = 5;
  					else if (id->eide_pio_modes & 2)
  						pio_mode = 4;
  					else
  						pio_mode = 3;
  				}
  			}
  		}
  
  		if (overridden)
  			printk(KERN_INFO "%s: tPIO > 2, assuming tPIO = 2\n",
  					 drive->name);
  
  		/*
  		 * Conservative "downgrade" for all pre-ATA2 drives
  		 */
  		if ((drive->hwif->host_flags & IDE_HFLAG_PIO_NO_DOWNGRADE) == 0 &&
  		    pio_mode && pio_mode < 4) {
  			pio_mode--;
  			printk(KERN_INFO "%s: applying conservative "
  					 "PIO \"downgrade\"\n", drive->name);
  		}
  	}
  
  	if (pio_mode > max_mode)
  		pio_mode = max_mode;
  
  	return pio_mode;
  }
  
  EXPORT_SYMBOL_GPL(ide_get_best_pio_mode);
  
  /* req_pio == "255" for auto-tune */
  void ide_set_pio(ide_drive_t *drive, u8 req_pio)
  {
  	ide_hwif_t *hwif = drive->hwif;
  	u8 host_pio, pio;
  
  	if (hwif->set_pio_mode == NULL)
  		return;
  
  	BUG_ON(hwif->pio_mask == 0x00);
  
  	host_pio = fls(hwif->pio_mask) - 1;
  
  	pio = ide_get_best_pio_mode(drive, req_pio, host_pio);
  
  	/*
  	 * TODO:
  	 * - report device max PIO mode
  	 * - check req_pio != 255 against device max PIO mode
  	 */
  	printk(KERN_DEBUG "%s: host max PIO%d wanted PIO%d%s selected PIO%d\n",
  			  drive->name, host_pio, req_pio,
  			  req_pio == 255 ? "(auto-tune)" : "", pio);
  
  	(void)ide_set_pio_mode(drive, XFER_PIO_0 + pio);
  }
  
  EXPORT_SYMBOL_GPL(ide_set_pio);
  
  /**
   *	ide_toggle_bounce	-	handle bounce buffering
   *	@drive: drive to update
   *	@on: on/off boolean
   *
   *	Enable or disable bounce buffering for the device. Drives move
   *	between PIO and DMA and that changes the rules we need.
   */
   
  void ide_toggle_bounce(ide_drive_t *drive, int on)
  {
  	u64 addr = BLK_BOUNCE_HIGH;	/* dma64_addr_t */
  
  	if (!PCI_DMA_BUS_IS_PHYS) {
  		addr = BLK_BOUNCE_ANY;
  	} else if (on && drive->media == ide_disk) {
  		if (HWIF(drive)->pci_dev)
  			addr = HWIF(drive)->pci_dev->dma_mask;
  	}
  
  	if (drive->queue)
  		blk_queue_bounce_limit(drive->queue, addr);
  }
  
  int ide_set_pio_mode(ide_drive_t *drive, const u8 mode)
  {
  	ide_hwif_t *hwif = drive->hwif;
  
  	if (hwif->set_pio_mode == NULL)
  		return -1;
  
  	/*
  	 * TODO: temporary hack for some legacy host drivers that didn't
  	 * set transfer mode on the device in ->set_pio_mode method...
  	 */
  	if (hwif->set_dma_mode == NULL) {
  		hwif->set_pio_mode(drive, mode - XFER_PIO_0);
  		return 0;
  	}
  
  	if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
  		if (ide_config_drive_speed(drive, mode))
  			return -1;
  		hwif->set_pio_mode(drive, mode - XFER_PIO_0);
  		return 0;
  	} else {
  		hwif->set_pio_mode(drive, mode - XFER_PIO_0);
  		return ide_config_drive_speed(drive, mode);
  	}
  }
  
  int ide_set_dma_mode(ide_drive_t *drive, const u8 mode)
  {
  	ide_hwif_t *hwif = drive->hwif;
  
  	if (hwif->set_dma_mode == NULL)
  		return -1;
  
  	if (hwif->host_flags & IDE_HFLAG_POST_SET_MODE) {
  		if (ide_config_drive_speed(drive, mode))
  			return -1;
  		hwif->set_dma_mode(drive, mode);
  		return 0;
  	} else {
  		hwif->set_dma_mode(drive, mode);
  		return ide_config_drive_speed(drive, mode);
  	}
  }
  
  EXPORT_SYMBOL_GPL(ide_set_dma_mode);
  
  /**
   *	ide_set_xfer_rate	-	set transfer rate
   *	@drive: drive to set
   *	@rate: speed to attempt to set
   *	
   *	General helper for setting the speed of an IDE device. This
   *	function knows about user enforced limits from the configuration
   *	which ->set_pio_mode/->set_dma_mode does not.
   */
  
  int ide_set_xfer_rate(ide_drive_t *drive, u8 rate)
  {
  	ide_hwif_t *hwif = drive->hwif;
  
  	if (hwif->set_dma_mode == NULL)
  		return -1;
  
  	rate = ide_rate_filter(drive, rate);
  
  	if (rate >= XFER_PIO_0 && rate <= XFER_PIO_5)
  		return ide_set_pio_mode(drive, rate);
  
  	/*
  	 * TODO: transfer modes 0x00-0x07 passed from the user-space are
  	 * currently handled here which needs fixing (please note that such
  	 * case could happen iff the transfer mode has already been set on
  	 * the device by ide-proc.c::set_xfer_rate()).
  	 */
  
  	return ide_set_dma_mode(drive, rate);
  }
  
  static void ide_dump_opcode(ide_drive_t *drive)
  {
  	struct request *rq;
  	u8 opcode = 0;
  	int found = 0;
  
  	spin_lock(&ide_lock);
  	rq = NULL;
  	if (HWGROUP(drive))
  		rq = HWGROUP(drive)->rq;
  	spin_unlock(&ide_lock);
  	if (!rq)
  		return;
  	if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
  	    rq->cmd_type == REQ_TYPE_ATA_TASK) {
  		char *args = rq->buffer;
  		if (args) {
  			opcode = args[0];
  			found = 1;
  		}
  	} else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
  		ide_task_t *args = rq->special;
  		if (args) {
  			task_struct_t *tf = (task_struct_t *) args->tfRegister;
  			opcode = tf->command;
  			found = 1;
  		}
  	}
  
  	printk("ide: failed opcode was: ");
  	if (!found)
  		printk("unknown\n");
  	else
  		printk("0x%02x\n", opcode);
  }
  
  static u8 ide_dump_ata_status(ide_drive_t *drive, const char *msg, u8 stat)
  {
  	ide_hwif_t *hwif = HWIF(drive);
  	unsigned long flags;
  	u8 err = 0;
  
  	local_irq_save(flags);
  	printk("%s: %s: status=0x%02x { ", drive->name, msg, stat);
  	if (stat & BUSY_STAT)
  		printk("Busy ");
  	else {
  		if (stat & READY_STAT)	printk("DriveReady ");
  		if (stat & WRERR_STAT)	printk("DeviceFault ");
  		if (stat & SEEK_STAT)	printk("SeekComplete ");
  		if (stat & DRQ_STAT)	printk("DataRequest ");
  		if (stat & ECC_STAT)	printk("CorrectedError ");
  		if (stat & INDEX_STAT)	printk("Index ");
  		if (stat & ERR_STAT)	printk("Error ");
  	}
  	printk("}\n");
  	if ((stat & (BUSY_STAT|ERR_STAT)) == ERR_STAT) {
  		err = hwif->INB(IDE_ERROR_REG);
  		printk("%s: %s: error=0x%02x { ", drive->name, msg, err);
  		if (err & ABRT_ERR)	printk("DriveStatusError ");
  		if (err & ICRC_ERR)
  			printk((err & ABRT_ERR) ? "BadCRC " : "BadSector ");
  		if (err & ECC_ERR)	printk("UncorrectableError ");
  		if (err & ID_ERR)	printk("SectorIdNotFound ");
  		if (err & TRK0_ERR)	printk("TrackZeroNotFound ");
  		if (err & MARK_ERR)	printk("AddrMarkNotFound ");
  		printk("}");
  		if ((err & (BBD_ERR | ABRT_ERR)) == BBD_ERR ||
  		    (err & (ECC_ERR|ID_ERR|MARK_ERR))) {
  			if (drive->addressing == 1) {
  				__u64 sectors = 0;
  				u32 low = 0, high = 0;
  				hwif->OUTB(drive->ctl&~0x80, IDE_CONTROL_REG);
  				low = ide_read_24(drive);
  				hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
  				high = ide_read_24(drive);
  				sectors = ((__u64)high << 24) | low;
  				printk(", LBAsect=%llu, high=%d, low=%d",
  				       (unsigned long long) sectors,
  				       high, low);
  			} else {
  				u8 cur = hwif->INB(IDE_SELECT_REG);
  				if (cur & 0x40) {	/* using LBA? */
  					printk(", LBAsect=%ld", (unsigned long)
  					 ((cur&0xf)<<24)
  					 |(hwif->INB(IDE_HCYL_REG)<<16)
  					 |(hwif->INB(IDE_LCYL_REG)<<8)
  					 | hwif->INB(IDE_SECTOR_REG));
  				} else {
  					printk(", CHS=%d/%d/%d",
  					 (hwif->INB(IDE_HCYL_REG)<<8) +
  					  hwif->INB(IDE_LCYL_REG),
  					  cur & 0xf,
  					  hwif->INB(IDE_SECTOR_REG));
  				}
  			}
  			if (HWGROUP(drive) && HWGROUP(drive)->rq)
  				printk(", sector=%llu",
  					(unsigned long long)HWGROUP(drive)->rq->sector);
  		}
  		printk("\n");
  	}
  	ide_dump_opcode(drive);
  	local_irq_restore(flags);
  	return err;
  }
  
  /**
   *	ide_dump_atapi_status       -       print human readable atapi status
   *	@drive: drive that status applies to
   *	@msg: text message to print
   *	@stat: status byte to decode
   *
   *	Error reporting, in human readable form (luxurious, but a memory hog).
   */
  
  static u8 ide_dump_atapi_status(ide_drive_t *drive, const char *msg, u8 stat)
  {
  	unsigned long flags;
  
  	atapi_status_t status;
  	atapi_error_t error;
  
  	status.all = stat;
  	error.all = 0;
  	local_irq_save(flags);
  	printk("%s: %s: status=0x%02x { ", drive->name, msg, stat);
  	if (status.b.bsy)
  		printk("Busy ");
  	else {
  		if (status.b.drdy)	printk("DriveReady ");
  		if (status.b.df)	printk("DeviceFault ");
  		if (status.b.dsc)	printk("SeekComplete ");
  		if (status.b.drq)	printk("DataRequest ");
  		if (status.b.corr)	printk("CorrectedError ");
  		if (status.b.idx)	printk("Index ");
  		if (status.b.check)	printk("Error ");
  	}
  	printk("}\n");
  	if (status.b.check && !status.b.bsy) {
  		error.all = HWIF(drive)->INB(IDE_ERROR_REG);
  		printk("%s: %s: error=0x%02x { ", drive->name, msg, error.all);
  		if (error.b.ili)	printk("IllegalLengthIndication ");
  		if (error.b.eom)	printk("EndOfMedia ");
  		if (error.b.abrt)	printk("AbortedCommand ");
  		if (error.b.mcr)	printk("MediaChangeRequested ");
  		if (error.b.sense_key)	printk("LastFailedSense=0x%02x ",
  						error.b.sense_key);
  		printk("}\n");
  	}
  	ide_dump_opcode(drive);
  	local_irq_restore(flags);
  	return error.all;
  }
  
  /**
   *	ide_dump_status		-	translate ATA/ATAPI error
   *	@drive: drive the error occured on
   *	@msg: information string
   *	@stat: status byte
   *
   *	Error reporting, in human readable form (luxurious, but a memory hog).
   *	Combines the drive name, message and status byte to provide a
   *	user understandable explanation of the device error.
   */
  
  u8 ide_dump_status(ide_drive_t *drive, const char *msg, u8 stat)
  {
  	if (drive->media == ide_disk)
  		return ide_dump_ata_status(drive, msg, stat);
  	return ide_dump_atapi_status(drive, msg, stat);
  }
  
  EXPORT_SYMBOL(ide_dump_status);
  