ide-taskfile.c

linux 内核源代码

/*
 * linux/drivers/ide/ide-taskfile.c	Version 0.38	March 05, 2003
 *
 *  Copyright (C) 2000-2002	Michael Cornwell <[e-mail]>
 *  Copyright (C) 2000-2002	Andre Hedrick <[e-mail]>
 *  Copyright (C) 2001-2002	Klaus Smolin
 *					IBM Storage Technology Division
 *  Copyright (C) 2003-2004	Bartlomiej Zolnierkiewicz
 *
 *  The big the bad and the ugly.
 */

#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/sched.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 <linux/scatterlist.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>

static void ata_bswap_data (void *buffer, int wcount)
{
	u16 *p = buffer;

	while (wcount--) {
		*p = *p << 8 | *p >> 8; p++;
		*p = *p << 8 | *p >> 8; p++;
	}
}

static void taskfile_input_data(ide_drive_t *drive, void *buffer, u32 wcount)
{
	HWIF(drive)->ata_input_data(drive, buffer, wcount);
	if (drive->bswap)
		ata_bswap_data(buffer, wcount);
}

static void taskfile_output_data(ide_drive_t *drive, void *buffer, u32 wcount)
{
	if (drive->bswap) {
		ata_bswap_data(buffer, wcount);
		HWIF(drive)->ata_output_data(drive, buffer, wcount);
		ata_bswap_data(buffer, wcount);
	} else {
		HWIF(drive)->ata_output_data(drive, buffer, wcount);
	}
}

int taskfile_lib_get_identify (ide_drive_t *drive, u8 *buf)
{
	ide_task_t args;
	memset(&args, 0, sizeof(ide_task_t));
	args.tfRegister[IDE_NSECTOR_OFFSET]	= 0x01;
	if (drive->media == ide_disk)
		args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_IDENTIFY;
	else
		args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_PIDENTIFY;
	args.command_type = IDE_DRIVE_TASK_IN;
	args.data_phase   = TASKFILE_IN;
	args.handler	  = &task_in_intr;
	return ide_raw_taskfile(drive, &args, buf);
}

ide_startstop_t do_rw_taskfile (ide_drive_t *drive, ide_task_t *task)
{
	ide_hwif_t *hwif	= HWIF(drive);
	task_struct_t *taskfile	= (task_struct_t *) task->tfRegister;
	hob_struct_t *hobfile	= (hob_struct_t *) task->hobRegister;
	u8 HIHI			= (drive->addressing == 1) ? 0xE0 : 0xEF;

	/* ALL Command Block Executions SHALL clear nIEN, unless otherwise */
	if (IDE_CONTROL_REG) {
		/* clear nIEN */
		hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
	}
	SELECT_MASK(drive, 0);

	if (drive->addressing == 1) {
		hwif->OUTB(hobfile->feature, IDE_FEATURE_REG);
		hwif->OUTB(hobfile->sector_count, IDE_NSECTOR_REG);
		hwif->OUTB(hobfile->sector_number, IDE_SECTOR_REG);
		hwif->OUTB(hobfile->low_cylinder, IDE_LCYL_REG);
		hwif->OUTB(hobfile->high_cylinder, IDE_HCYL_REG);
	}

	hwif->OUTB(taskfile->feature, IDE_FEATURE_REG);
	hwif->OUTB(taskfile->sector_count, IDE_NSECTOR_REG);
	hwif->OUTB(taskfile->sector_number, IDE_SECTOR_REG);
	hwif->OUTB(taskfile->low_cylinder, IDE_LCYL_REG);
	hwif->OUTB(taskfile->high_cylinder, IDE_HCYL_REG);

	hwif->OUTB((taskfile->device_head & HIHI) | drive->select.all, IDE_SELECT_REG);

	if (task->handler != NULL) {
		if (task->prehandler != NULL) {
			hwif->OUTBSYNC(drive, taskfile->command, IDE_COMMAND_REG);
			ndelay(400);	/* FIXME */
			return task->prehandler(drive, task->rq);
		}
		ide_execute_command(drive, taskfile->command, task->handler, WAIT_WORSTCASE, NULL);
		return ide_started;
	}

	if (!drive->using_dma)
		return ide_stopped;

	switch (taskfile->command) {
		case WIN_WRITEDMA_ONCE:
		case WIN_WRITEDMA:
		case WIN_WRITEDMA_EXT:
		case WIN_READDMA_ONCE:
		case WIN_READDMA:
		case WIN_READDMA_EXT:
		case WIN_IDENTIFY_DMA:
			if (!hwif->dma_setup(drive)) {
				hwif->dma_exec_cmd(drive, taskfile->command);
				hwif->dma_start(drive);
				return ide_started;
			}
			break;
		default:
			if (task->handler == NULL)
				return ide_stopped;
	}

	return ide_stopped;
}

/*
 * set_multmode_intr() is invoked on completion of a WIN_SETMULT cmd.
 */
ide_startstop_t set_multmode_intr (ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	u8 stat;

	if (OK_STAT(stat = hwif->INB(IDE_STATUS_REG),READY_STAT,BAD_STAT)) {
		drive->mult_count = drive->mult_req;
	} else {
		drive->mult_req = drive->mult_count = 0;
		drive->special.b.recalibrate = 1;
		(void) ide_dump_status(drive, "set_multmode", stat);
	}
	return ide_stopped;
}

/*
 * set_geometry_intr() is invoked on completion of a WIN_SPECIFY cmd.
 */
ide_startstop_t set_geometry_intr (ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	int retries = 5;
	u8 stat;

	while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
		udelay(10);

	if (OK_STAT(stat, READY_STAT, BAD_STAT))
		return ide_stopped;

	if (stat & (ERR_STAT|DRQ_STAT))
		return ide_error(drive, "set_geometry_intr", stat);

	BUG_ON(HWGROUP(drive)->handler != NULL);
	ide_set_handler(drive, &set_geometry_intr, WAIT_WORSTCASE, NULL);
	return ide_started;
}

/*
 * recal_intr() is invoked on completion of a WIN_RESTORE (recalibrate) cmd.
 */
ide_startstop_t recal_intr (ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	u8 stat;

	if (!OK_STAT(stat = hwif->INB(IDE_STATUS_REG), READY_STAT, BAD_STAT))
		return ide_error(drive, "recal_intr", stat);
	return ide_stopped;
}

/*
 * Handler for commands without a data phase
 */
ide_startstop_t task_no_data_intr (ide_drive_t *drive)
{
	ide_task_t *args	= HWGROUP(drive)->rq->special;
	ide_hwif_t *hwif	= HWIF(drive);
	u8 stat;

	local_irq_enable_in_hardirq();
	if (!OK_STAT(stat = hwif->INB(IDE_STATUS_REG),READY_STAT,BAD_STAT)) {
		return ide_error(drive, "task_no_data_intr", stat);
		/* calls ide_end_drive_cmd */
	}
	if (args)
		ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));

	return ide_stopped;
}

EXPORT_SYMBOL(task_no_data_intr);

static u8 wait_drive_not_busy(ide_drive_t *drive)
{
	ide_hwif_t *hwif = HWIF(drive);
	int retries;
	u8 stat;

	/*
	 * Last sector was transfered, wait until drive is ready.
	 * This can take up to 10 usec, but we will wait max 1 ms
	 * (drive_cmd_intr() waits that long).
	 */
	for (retries = 0; retries < 100; retries++) {
		if ((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT)
			udelay(10);
		else
			break;
	}

	if (stat & BUSY_STAT)
		printk(KERN_ERR "%s: drive still BUSY!\n", drive->name);

	return stat;
}

static void ide_pio_sector(ide_drive_t *drive, unsigned int write)
{
	ide_hwif_t *hwif = drive->hwif;
	struct scatterlist *sg = hwif->sg_table;
	struct scatterlist *cursg = hwif->cursg;
	struct page *page;
#ifdef CONFIG_HIGHMEM
	unsigned long flags;
#endif
	unsigned int offset;
	u8 *buf;

	cursg = hwif->cursg;
	if (!cursg) {
		cursg = sg;
		hwif->cursg = sg;
	}

	page = sg_page(cursg);
	offset = cursg->offset + hwif->cursg_ofs * SECTOR_SIZE;

	/* get the current page and offset */
	page = nth_page(page, (offset >> PAGE_SHIFT));
	offset %= PAGE_SIZE;

#ifdef CONFIG_HIGHMEM
	local_irq_save(flags);
#endif
	buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset;

	hwif->nleft--;
	hwif->cursg_ofs++;

	if ((hwif->cursg_ofs * SECTOR_SIZE) == cursg->length) {
		hwif->cursg = sg_next(hwif->cursg);
		hwif->cursg_ofs = 0;
	}

	/* do the actual data transfer */
	if (write)
		taskfile_output_data(drive, buf, SECTOR_WORDS);
	else
		taskfile_input_data(drive, buf, SECTOR_WORDS);

	kunmap_atomic(buf, KM_BIO_SRC_IRQ);
#ifdef CONFIG_HIGHMEM
	local_irq_restore(flags);
#endif
}

static void ide_pio_multi(ide_drive_t *drive, unsigned int write)
{
	unsigned int nsect;

	nsect = min_t(unsigned int, drive->hwif->nleft, drive->mult_count);
	while (nsect--)
		ide_pio_sector(drive, write);
}

static void ide_pio_datablock(ide_drive_t *drive, struct request *rq,
				     unsigned int write)
{
	if (rq->bio)	/* fs request */
		rq->errors = 0;

	touch_softlockup_watchdog();

	switch (drive->hwif->data_phase) {
	case TASKFILE_MULTI_IN:
	case TASKFILE_MULTI_OUT:
		ide_pio_multi(drive, write);
		break;
	default:
		ide_pio_sector(drive, write);
		break;
	}
}

static ide_startstop_t task_error(ide_drive_t *drive, struct request *rq,
				  const char *s, u8 stat)
{
	if (rq->bio) {
		ide_hwif_t *hwif = drive->hwif;
		int sectors = hwif->nsect - hwif->nleft;

		switch (hwif->data_phase) {
		case TASKFILE_IN:
			if (hwif->nleft)
				break;
			/* fall through */
		case TASKFILE_OUT:
			sectors--;
			break;
		case TASKFILE_MULTI_IN:
			if (hwif->nleft)
				break;
			/* fall through */
		case TASKFILE_MULTI_OUT:
			sectors -= drive->mult_count;
		default:
			break;
		}

		if (sectors > 0) {
			ide_driver_t *drv;

			drv = *(ide_driver_t **)rq->rq_disk->private_data;
			drv->end_request(drive, 1, sectors);
		}
	}
	return ide_error(drive, s, stat);
}

static void task_end_request(ide_drive_t *drive, struct request *rq, u8 stat)
{
	HWIF(drive)->cursg = NULL;

	if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
		ide_task_t *task = rq->special;

		if (task->tf_out_flags.all) {
			u8 err = drive->hwif->INB(IDE_ERROR_REG);
			ide_end_drive_cmd(drive, stat, err);
			return;
		}
	}

	if (rq->rq_disk) {
		ide_driver_t *drv;

		drv = *(ide_driver_t **)rq->rq_disk->private_data;;
		drv->end_request(drive, 1, rq->hard_nr_sectors);
	} else
		ide_end_request(drive, 1, rq->hard_nr_sectors);
}

/*
 * Handler for command with PIO data-in phase (Read/Read Multiple).
 */
ide_startstop_t task_in_intr (ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	struct request *rq = HWGROUP(drive)->rq;
	u8 stat = hwif->INB(IDE_STATUS_REG);

	/* new way for dealing with premature shared PCI interrupts */
	if (!OK_STAT(stat, DATA_READY, BAD_R_STAT)) {
		if (stat & (ERR_STAT | DRQ_STAT))
			return task_error(drive, rq, __FUNCTION__, stat);
		/* No data yet, so wait for another IRQ. */
		ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);
		return ide_started;
	}

	ide_pio_datablock(drive, rq, 0);

	/* If it was the last datablock check status and finish transfer. */
	if (!hwif->nleft) {
		stat = wait_drive_not_busy(drive);
		if (!OK_STAT(stat, 0, BAD_R_STAT))
			return task_error(drive, rq, __FUNCTION__, stat);
		task_end_request(drive, rq, stat);
		return ide_stopped;
	}

	/* Still data left to transfer. */
	ide_set_handler(drive, &task_in_intr, WAIT_WORSTCASE, NULL);

	return ide_started;
}
EXPORT_SYMBOL(task_in_intr);

/*
 * Handler for command with PIO data-out phase (Write/Write Multiple).
 */
static ide_startstop_t task_out_intr (ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	struct request *rq = HWGROUP(drive)->rq;
	u8 stat = hwif->INB(IDE_STATUS_REG);

	if (!OK_STAT(stat, DRIVE_READY, drive->bad_wstat))
		return task_error(drive, rq, __FUNCTION__, stat);

	/* Deal with unexpected ATA data phase. */
	if (((stat & DRQ_STAT) == 0) ^ !hwif->nleft)
		return task_error(drive, rq, __FUNCTION__, stat);

	if (!hwif->nleft) {
		task_end_request(drive, rq, stat);