ide-io.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,604 行 · 第 1/4 页

				args->hobRegister[IDE_HCYL_OFFSET]	= hwif->INB(IDE_HCYL_REG);
			}
		}
	} else if (blk_pm_request(rq)) {
#ifdef DEBUG_PM
		printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
			drive->name, rq->pm->pm_step, stat, err);
#endif
		DRIVER(drive)->complete_power_step(drive, rq, stat, err);
		if (rq->pm->pm_step == ide_pm_state_completed)
			ide_complete_pm_request(drive, rq);
		return;
	}

	spin_lock_irqsave(&ide_lock, flags);
	blkdev_dequeue_request(rq);

	if (blk_barrier_preflush(rq) || blk_barrier_postflush(rq))
		ide_complete_barrier(drive, rq, err);

	HWGROUP(drive)->rq = NULL;
	end_that_request_last(rq);
	spin_unlock_irqrestore(&ide_lock, flags);
}

EXPORT_SYMBOL(ide_end_drive_cmd);

/**
 *	try_to_flush_leftover_data	-	flush junk
 *	@drive: drive to flush
 *
 *	try_to_flush_leftover_data() is invoked in response to a drive
 *	unexpectedly having its DRQ_STAT bit set.  As an alternative to
 *	resetting the drive, this routine tries to clear the condition
 *	by read a sector's worth of data from the drive.  Of course,
 *	this may not help if the drive is *waiting* for data from *us*.
 */
void try_to_flush_leftover_data (ide_drive_t *drive)
{
	int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;

	if (drive->media != ide_disk)
		return;
	while (i > 0) {
		u32 buffer[16];
		u32 wcount = (i > 16) ? 16 : i;

		i -= wcount;
		HWIF(drive)->ata_input_data(drive, buffer, wcount);
	}
}

EXPORT_SYMBOL(try_to_flush_leftover_data);

/*
 * FIXME Add an ATAPI error
 */

/**
 *	ide_error	-	handle an error on the IDE
 *	@drive: drive the error occurred on
 *	@msg: message to report
 *	@stat: status bits
 *
 *	ide_error() takes action based on the error returned by the drive.
 *	For normal I/O that may well include retries. We deal with
 *	both new-style (taskfile) and old style command handling here.
 *	In the case of taskfile command handling there is work left to
 *	do
 */
 
ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
{
	ide_hwif_t *hwif;
	struct request *rq;
	u8 err;

	err = ide_dump_status(drive, msg, stat);
	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
		return ide_stopped;

	hwif = HWIF(drive);
	/* retry only "normal" I/O: */
	if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) {
		rq->errors = 1;
		ide_end_drive_cmd(drive, stat, err);
		return ide_stopped;
	}
	if (rq->flags & REQ_DRIVE_TASKFILE) {
		rq->errors = 1;
		ide_end_drive_cmd(drive, stat, err);
		return ide_stopped;
	}

	if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
		 /* other bits are useless when BUSY */
		rq->errors |= ERROR_RESET;
	} else {
		if (drive->media != ide_disk)
			goto media_out;

		if (stat & ERR_STAT) {
			/* err has different meaning on cdrom and tape */
			if (err == ABRT_ERR) {
				if (drive->select.b.lba &&
				    (hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY))
					/* some newer drives don't
					 * support WIN_SPECIFY
					 */
					return ide_stopped;
			} else if ((err & BAD_CRC) == BAD_CRC) {
				drive->crc_count++;
				/* UDMA crc error -- just retry the operation */
			} else if (err & (BBD_ERR | ECC_ERR)) {
				/* retries won't help these */
				rq->errors = ERROR_MAX;
			} else if (err & TRK0_ERR) {
				/* help it find track zero */
				rq->errors |= ERROR_RECAL;
			}
		}
media_out:
		if ((stat & DRQ_STAT) && rq_data_dir(rq) != WRITE)
			try_to_flush_leftover_data(drive);
	}
	if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT)) {
		/* force an abort */
		hwif->OUTB(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);
	}
	if (rq->errors >= ERROR_MAX) {
		DRIVER(drive)->end_request(drive, 0, 0);
	} else {
		if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
			++rq->errors;
			return ide_do_reset(drive);
		}
		if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
			drive->special.b.recalibrate = 1;
		++rq->errors;
	}
	return ide_stopped;
}

EXPORT_SYMBOL(ide_error);

/**
 *	ide_abort	-	abort pending IDE operatins
 *	@drive: drive the error occurred on
 *	@msg: message to report
 *
 *	ide_abort kills and cleans up when we are about to do a 
 *	host initiated reset on active commands. Longer term we
 *	want handlers to have sensible abort handling themselves
 *
 *	This differs fundamentally from ide_error because in 
 *	this case the command is doing just fine when we
 *	blow it away.
 */
 
ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
{
	ide_hwif_t *hwif;
	struct request *rq;

	if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
		return ide_stopped;

	hwif = HWIF(drive);
	/* retry only "normal" I/O: */
	if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) {
		rq->errors = 1;
		ide_end_drive_cmd(drive, BUSY_STAT, 0);
		return ide_stopped;
	}
	if (rq->flags & REQ_DRIVE_TASKFILE) {
		rq->errors = 1;
		ide_end_drive_cmd(drive, BUSY_STAT, 0);
		return ide_stopped;
	}

	rq->errors |= ERROR_RESET;
	DRIVER(drive)->end_request(drive, 0, 0);
	return ide_stopped;
}

EXPORT_SYMBOL(ide_abort);

/**
 *	ide_cmd		-	issue a simple drive command
 *	@drive: drive the command is for
 *	@cmd: command byte
 *	@nsect: sector byte
 *	@handler: handler for the command completion
 *
 *	Issue a simple drive command with interrupts.
 *	The drive must be selected beforehand.
 */

void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect, ide_handler_t *handler)
{
	ide_hwif_t *hwif = HWIF(drive);
	if (IDE_CONTROL_REG)
		hwif->OUTB(drive->ctl,IDE_CONTROL_REG);	/* clear nIEN */
	SELECT_MASK(drive,0);
	hwif->OUTB(nsect,IDE_NSECTOR_REG);
	ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
}

EXPORT_SYMBOL(ide_cmd);

/**
 *	drive_cmd_intr		- 	drive command completion interrupt
 *	@drive: drive the completion interrupt occurred on
 *
 *	drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
 *	We do any necessary daya reading and then wait for the drive to
 *	go non busy. At that point we may read the error data and complete
 *	the request
 */
 
ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
{
	struct request *rq = HWGROUP(drive)->rq;
	ide_hwif_t *hwif = HWIF(drive);
	u8 *args = (u8 *) rq->buffer;
	u8 stat = hwif->INB(IDE_STATUS_REG);
	int retries = 10;

	local_irq_enable();
	if ((stat & DRQ_STAT) && args && args[3]) {
		u8 io_32bit = drive->io_32bit;
		drive->io_32bit = 0;
		hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
		drive->io_32bit = io_32bit;
		while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
			udelay(100);
	}

	if (!OK_STAT(stat, READY_STAT, BAD_STAT) && DRIVER(drive) != NULL)
		return DRIVER(drive)->error(drive, "drive_cmd", stat);
		/* calls ide_end_drive_cmd */
	ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
	return ide_stopped;
}

EXPORT_SYMBOL(drive_cmd_intr);

/**
 *	do_special		-	issue some special commands
 *	@drive: drive the command is for
 *
 *	do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
 *	commands to a drive.  It used to do much more, but has been scaled
 *	back.
 */

ide_startstop_t do_special (ide_drive_t *drive)
{
	special_t *s = &drive->special;

#ifdef DEBUG
	printk("%s: do_special: 0x%02x\n", drive->name, s->all);
#endif
	if (s->b.set_tune) {
		s->b.set_tune = 0;
		if (HWIF(drive)->tuneproc != NULL)
			HWIF(drive)->tuneproc(drive, drive->tune_req);
		return ide_stopped;
	}
	else
		return DRIVER(drive)->special(drive);
}

EXPORT_SYMBOL(do_special);

/**
 *	execute_drive_command	-	issue special drive command
 *	@drive: the drive to issue th command on
 *	@rq: the request structure holding the command
 *
 *	execute_drive_cmd() issues a special drive command,  usually 
 *	initiated by ioctl() from the external hdparm program. The
 *	command can be a drive command, drive task or taskfile 
 *	operation. Weirdly you can call it with NULL to wait for
 *	all commands to finish. Don't do this as that is due to change
 */

ide_startstop_t execute_drive_cmd (ide_drive_t *drive, struct request *rq)
{
	ide_hwif_t *hwif = HWIF(drive);
	if (rq->flags & REQ_DRIVE_TASKFILE) {
 		ide_task_t *args = rq->special;
 
		if (!args)
			goto done;

		hwif->data_phase = args->data_phase;

		if (args->tf_out_flags.all != 0) 
			return flagged_taskfile(drive, args);
		return do_rw_taskfile(drive, args);
	} else if (rq->flags & REQ_DRIVE_TASK) {
		u8 *args = rq->buffer;
		u8 sel;
 
		if (!args)
			goto done;
#ifdef DEBUG
 		printk("%s: DRIVE_TASK_CMD ", drive->name);
 		printk("cmd=0x%02x ", args[0]);
 		printk("fr=0x%02x ", args[1]);
 		printk("ns=0x%02x ", args[2]);
 		printk("sc=0x%02x ", args[3]);
 		printk("lcyl=0x%02x ", args[4]);
 		printk("hcyl=0x%02x ", args[5]);
 		printk("sel=0x%02x\n", args[6]);
#endif
 		hwif->OUTB(args[1], IDE_FEATURE_REG);
 		hwif->OUTB(args[3], IDE_SECTOR_REG);
 		hwif->OUTB(args[4], IDE_LCYL_REG);
 		hwif->OUTB(args[5], IDE_HCYL_REG);
 		sel = (args[6] & ~0x10);
 		if (drive->select.b.unit)
 			sel |= 0x10;
 		hwif->OUTB(sel, IDE_SELECT_REG);
 		ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
 		return ide_started;
 	} else if (rq->flags & REQ_DRIVE_CMD) {
 		u8 *args = rq->buffer;

		if (!args)
			goto done;
#ifdef DEBUG
 		printk("%s: DRIVE_CMD ", drive->name);
 		printk("cmd=0x%02x ", args[0]);
 		printk("sc=0x%02x ", args[1]);
 		printk("fr=0x%02x ", args[2]);
 		printk("xx=0x%02x\n", args[3]);
#endif
 		if (args[0] == WIN_SMART) {
 			hwif->OUTB(0x4f, IDE_LCYL_REG);
 			hwif->OUTB(0xc2, IDE_HCYL_REG);
 			hwif->OUTB(args[2],IDE_FEATURE_REG);
 			hwif->OUTB(args[1],IDE_SECTOR_REG);
 			ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
 			return ide_started;
 		}
 		hwif->OUTB(args[2],IDE_FEATURE_REG);
 		ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
 		return ide_started;
 	}

done:
 	/*
 	 * NULL is actually a valid way of waiting for
 	 * all current requests to be flushed from the queue.
 	 */
#ifdef DEBUG
 	printk("%s: DRIVE_CMD (null)\n", drive->name);
#endif
 	ide_end_drive_cmd(drive,
			hwif->INB(IDE_STATUS_REG),
			hwif->INB(IDE_ERROR_REG));
 	return ide_stopped;
}

EXPORT_SYMBOL(execute_drive_cmd);

/**
 *	start_request	-	start of I/O and command issuing for IDE
 *
 *	start_request() initiates handling of a new I/O request. It
 *	accepts commands and I/O (read/write) requests. It also does
 *	the final remapping for weird stuff like EZDrive. Once 
 *	device mapper can work sector level the EZDrive stuff can go away
 *
 *	FIXME: this function needs a rename
 */
 
ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
{
	ide_startstop_t startstop;
	sector_t block;

	BUG_ON(!(rq->flags & REQ_STARTED));

#ifdef DEBUG
	printk("%s: start_request: current=0x%08lx\n",
		HWIF(drive)->name, (unsigned long) rq);
#endif

	/* bail early if we've exceeded max_failures */
	if (drive->max_failures && (drive->failures > drive->max_failures)) {
		goto kill_rq;
	}

	/*
	 * bail early if we've sent a device to sleep, however how to wake
	 * this needs to be a masked flag.  FIXME for proper operations.
	 */
	if (drive->suspend_reset)