ide-dma.c

ep9315平台下硬盘驱动的源码

			} else {
				u32 xcount, bcount = 0x10000 - (cur_addr & 0xffff);

				if (bcount > cur_len)
					bcount = cur_len;
				*table++ = cpu_to_le32(cur_addr);
				xcount = bcount & 0xffff;
				if (is_trm290)
					xcount = ((xcount >> 2) - 1) << 16;
				if (xcount == 0x0000) {
	/* 
	 * Most chipsets correctly interpret a length of 0x0000 as 64KB,
	 * but at least one (e.g. CS5530) misinterprets it as zero (!).
	 * So here we break the 64KB entry into two 32KB entries instead.
	 */
					if (count++ >= PRD_ENTRIES) {
						printk("%s: DMA table too small\n", drive->name);
						goto use_pio_instead;
					}
					*table++ = cpu_to_le32(0x8000);
					*table++ = cpu_to_le32(cur_addr + 0x8000);
					xcount = 0x8000;
				}
				*table++ = cpu_to_le32(xcount);
				cur_addr += bcount;
				cur_len -= bcount;
			}
		}

		sg++;
		i--;
	}

	if (count) {
		if (!is_trm290)
			*--table |= cpu_to_le32(0x80000000);
		return count;
	}
	printk("%s: empty DMA table?\n", drive->name);
use_pio_instead:
	pci_unmap_sg(hwif->pci_dev,
		     hwif->sg_table,
		     hwif->sg_nents,
		     hwif->sg_dma_direction);
	hwif->sg_dma_active = 0;
	return 0; /* revert to PIO for this request */
}

EXPORT_SYMBOL_GPL(ide_build_dmatable);

/**
 *	ide_destroy_dmatable	-	clean up DMA mapping
 *	@drive: The drive to unmap
 *
 *	Teardown mappings after DMA has completed. This must be called
 *	after the completion of each use of ide_build_dmatable and before
 *	the next use of ide_build_dmatable. Failure to do so will cause
 *	an oops as only one mapping can be live for each target at a given
 *	time.
 */
 
void ide_destroy_dmatable (ide_drive_t *drive)
{
	struct pci_dev *dev = HWIF(drive)->pci_dev;
	struct scatterlist *sg = HWIF(drive)->sg_table;
	int nents = HWIF(drive)->sg_nents;

	pci_unmap_sg(dev, sg, nents, HWIF(drive)->sg_dma_direction);
	HWIF(drive)->sg_dma_active = 0;
}

EXPORT_SYMBOL_GPL(ide_destroy_dmatable);

/**
 *	config_drive_for_dma	-	attempt to activate IDE DMA
 *	@drive: the drive to place in DMA mode
 *
 *	If the drive supports at least mode 2 DMA or UDMA of any kind
 *	then attempt to place it into DMA mode. Drives that are known to
 *	support DMA but predate the DMA properties or that are known
 *	to have DMA handling bugs are also set up appropriately based
 *	on the good/bad drive lists.
 */
 
static int config_drive_for_dma (ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	ide_hwif_t *hwif = HWIF(drive);

	if ((id->capability & 1) && hwif->autodma) {
		/* Consult the list of known "bad" drives */
		if (hwif->ide_dma_bad_drive(drive))
			return hwif->ide_dma_off(drive);

		/*
		 * Enable DMA on any drive that has
		 * UltraDMA (mode 0/1/2/3/4/5/6) enabled
		 */
		if ((id->field_valid & 4) && ((id->dma_ultra >> 8) & 0x7f))
			return hwif->ide_dma_on(drive);
		/*
		 * Enable DMA on any drive that has mode2 DMA
		 * (multi or single) enabled
		 */
		if (id->field_valid & 2)	/* regular DMA */
			if ((id->dma_mword & 0x404) == 0x404 ||
			    (id->dma_1word & 0x404) == 0x404)
				return hwif->ide_dma_on(drive);

		/* Consult the list of known "good" drives */
		if (hwif->ide_dma_good_drive(drive))
			return hwif->ide_dma_on(drive);
	}
//	if (hwif->tuneproc != NULL) hwif->tuneproc(drive, 255);
	return hwif->ide_dma_off_quietly(drive);
}

/**
 *	dma_timer_expiry	-	handle a DMA timeout
 *	@drive: Drive that timed out
 *
 *	An IDE DMA transfer timed out. In the event of an error we ask
 *	the driver to resolve the problem, if a DMA transfer is still
 *	in progress we continue to wait (arguably we need to add a 
 *	secondary 'I dont care what the drive thinks' timeout here)
 *	Finally if we have an interrupt but for some reason got the
 *	timeout first we complete the I/O. This can occur if an 
 *	interrupt is lost or due to bugs.
 */
 
static int dma_timer_expiry (ide_drive_t *drive)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u8 dma_stat		= hwif->INB(hwif->dma_status);

	printk(KERN_WARNING "%s: dma_timer_expiry: dma status == 0x%02x\n",
		drive->name, dma_stat);

	if ((dma_stat & 0x18) == 0x18)	/* BUSY Stupid Early Timer !! */
		return WAIT_CMD;

	HWGROUP(drive)->expiry = NULL;	/* one free ride for now */

	/* 1 dmaing, 2 error, 4 intr */
	
	if (dma_stat & 2) {	/* ERROR */
		(void) hwif->ide_dma_end(drive);
		return DRIVER(drive)->error(drive,
			"dma_timer_expiry", hwif->INB(IDE_STATUS_REG));
	}
	if (dma_stat & 1)	/* DMAing */
		return WAIT_CMD;

	if (dma_stat & 4)	/* Got an Interrupt */
		HWGROUP(drive)->handler(drive);

	return 0;
}

/**
 *	__ide_dma_host_off	-	Generic DMA kill
 *	@drive: drive to control
 *
 *	Perform the generic IDE controller DMA off operation. This
 *	works for most IDE bus mastering controllers
 */

int __ide_dma_host_off (ide_drive_t *drive)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u8 unit			= (drive->select.b.unit & 0x01);
	u8 dma_stat		= hwif->INB(hwif->dma_status);

	hwif->OUTB((dma_stat & ~(1<<(5+unit))), hwif->dma_status);
	return 0;
}

EXPORT_SYMBOL(__ide_dma_host_off);

/**
 *	__ide_dma_host_off_quietly	-	Generic DMA kill
 *	@drive: drive to control
 *
 *	Turn off the current DMA on this IDE controller. 
 */

int __ide_dma_off_quietly (ide_drive_t *drive)
{
	drive->using_dma = 0;
	ide_toggle_bounce(drive, 0);
	return HWIF(drive)->ide_dma_host_off(drive);
}

EXPORT_SYMBOL(__ide_dma_off_quietly);

/**
 *	__ide_dma_host_off	-	Generic DMA kill
 *	@drive: drive to control
 *
 *	Turn off the current DMA on this IDE controller. Inform the
 *	user that DMA has been disabled. 
 */

int __ide_dma_off (ide_drive_t *drive)
{
	printk(KERN_INFO "%s: DMA disabled\n", drive->name);
	return HWIF(drive)->ide_dma_off_quietly(drive);
}

EXPORT_SYMBOL(__ide_dma_off);

/**
 *	__ide_dma_host_on	-	Enable DMA on a host
 *	@drive: drive to enable for DMA
 *
 *	Enable DMA on an IDE controller following generic bus mastering
 *	IDE controller behaviour
 */
 
int __ide_dma_host_on (ide_drive_t *drive)
{
	if (drive->using_dma) {
		ide_hwif_t *hwif	= HWIF(drive);
		u8 unit			= (drive->select.b.unit & 0x01);
		u8 dma_stat		= hwif->INB(hwif->dma_status);

		hwif->OUTB((dma_stat|(1<<(5+unit))), hwif->dma_status);
		return 0;
	}
	return 1;
}

EXPORT_SYMBOL(__ide_dma_host_on);

/**
 *	__ide_dma_on		-	Enable DMA on a device
 *	@drive: drive to enable DMA on
 *
 *	Enable IDE DMA for a device on this IDE controller.
 */
 
int __ide_dma_on (ide_drive_t *drive)
{
	drive->using_dma = 1;
	ide_toggle_bounce(drive, 1);
	return HWIF(drive)->ide_dma_host_on(drive);
}

EXPORT_SYMBOL(__ide_dma_on);

/**
 *	__ide_dma_check		-	check DMA setup
 *	@drive: drive to check
 *
 *	Don't use - due for extermination
 */
 
int __ide_dma_check (ide_drive_t *drive)
{
	return config_drive_for_dma(drive);
}

EXPORT_SYMBOL(__ide_dma_check);

int __ide_dma_read (ide_drive_t *drive /*, struct request *rq */)
{
	ide_hwif_t *hwif	= HWIF(drive);
	struct request *rq	= HWGROUP(drive)->rq;
//	ide_task_t *args	= rq->special;
	unsigned int reading	= 1 << 3;
	unsigned int count	= 0;
	u8 dma_stat = 0, lba48	= (drive->addressing == 1) ? 1 : 0;
	task_ioreg_t command	= WIN_NOP;

	if (!(count = ide_build_dmatable(drive, rq, PCI_DMA_FROMDEVICE)))
		/* try PIO instead of DMA */
		return 1;
	/* PRD table */
	hwif->OUTL(hwif->dmatable_dma, hwif->dma_prdtable);
	/* specify r/w */
	hwif->OUTB(reading, hwif->dma_command);
	/* read dma_status for INTR & ERROR flags */
	dma_stat = hwif->INB(hwif->dma_status);
	/* clear INTR & ERROR flags */
	hwif->OUTB(dma_stat|6, hwif->dma_status);
	drive->waiting_for_dma = 1;
	if (drive->media != ide_disk)
		return 0;
	/*
	 * FIX ME to use only ACB ide_task_t args Struct
	 */
#if 0
	{
		ide_task_t *args = rq->special;
		command = args->tfRegister[IDE_COMMAND_OFFSET];
	}
#else
	command = (lba48) ? WIN_READDMA_EXT : WIN_READDMA;
	if (rq->cmd == IDE_DRIVE_TASKFILE) {
		ide_task_t *args = rq->special;
		command = args->tfRegister[IDE_COMMAND_OFFSET];
	}
#endif
	/* issue cmd to drive */
	ide_execute_command(drive, command, &ide_dma_intr, 2*WAIT_CMD, dma_timer_expiry);
	return HWIF(drive)->ide_dma_count(drive);
}

EXPORT_SYMBOL(__ide_dma_read);

int __ide_dma_write (ide_drive_t *drive /*, struct request *rq */)
{
	ide_hwif_t *hwif	= HWIF(drive);
	struct request *rq	= HWGROUP(drive)->rq;
//	ide_task_t *args	= rq->special;
	unsigned int reading	= 0;
	unsigned int count	= 0;
	u8 dma_stat = 0, lba48	= (drive->addressing == 1) ? 1 : 0;
	task_ioreg_t command	= WIN_NOP;

	if (!(count = ide_build_dmatable(drive, rq, PCI_DMA_TODEVICE)))
		/* try PIO instead of DMA */
		return 1;
	/* PRD table */
	hwif->OUTL(hwif->dmatable_dma, hwif->dma_prdtable);
	/* specify r/w */
	hwif->OUTB(reading, hwif->dma_command);
	/* read dma_status for INTR & ERROR flags */
	dma_stat = hwif->INB(hwif->dma_status);
	/* clear INTR & ERROR flags */
	hwif->OUTB(dma_stat|6, hwif->dma_status);
	drive->waiting_for_dma = 1;
	if (drive->media != ide_disk)
		return 0;
	/*
	 * FIX ME to use only ACB ide_task_t args Struct
	 */
#if 0
	{
		ide_task_t *args = rq->special;
		command = args->tfRegister[IDE_COMMAND_OFFSET];
	}
#else
	command = (lba48) ? WIN_WRITEDMA_EXT : WIN_WRITEDMA;
	if (rq->cmd == IDE_DRIVE_TASKFILE) {
		ide_task_t *args = rq->special;
		command = args->tfRegister[IDE_COMMAND_OFFSET];
	}
#endif
	/* issue cmd to drive */
	ide_execute_command(drive, command, &ide_dma_intr, 2*WAIT_CMD, dma_timer_expiry);
	return HWIF(drive)->ide_dma_count(drive);
}

EXPORT_SYMBOL(__ide_dma_write);

int __ide_dma_begin (ide_drive_t *drive)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u8 dma_cmd		= hwif->INB(hwif->dma_command);

	/* Note that this is done *after* the cmd has
	 * been issued to the drive, as per the BM-IDE spec.
	 * The Promise Ultra33 doesn't work correctly when
	 * we do this part before issuing the drive cmd.
	 */
	/* start DMA */
	hwif->OUTB(dma_cmd|1, hwif->dma_command);
	return 0;
}

EXPORT_SYMBOL(__ide_dma_begin);

/* returns 1 on error, 0 otherwise */
int __ide_dma_end (ide_drive_t *drive)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u8 dma_stat = 0, dma_cmd = 0;

	drive->waiting_for_dma = 0;
	/* get dma_command mode */
	dma_cmd = hwif->INB(hwif->dma_command);
	/* stop DMA */
	hwif->OUTB(dma_cmd&~1, hwif->dma_command);
	/* get DMA status */
	dma_stat = hwif->INB(hwif->dma_status);
	/* clear the INTR & ERROR bits */
	hwif->OUTB(dma_stat|6, hwif->dma_status);
	/* purge DMA mappings */
	ide_destroy_dmatable(drive);
	/* verify good DMA status */
	return (dma_stat & 7) != 4 ? (0x10 | dma_stat) : 0;
}

EXPORT_SYMBOL(__ide_dma_end);

/* returns 1 if dma irq issued, 0 otherwise */
int __ide_dma_test_irq (ide_drive_t *drive)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u8 dma_stat		= hwif->INB(hwif->dma_status);

#if 0  /* do not set unless you know what you are doing */
	if (dma_stat & 4) {
		u8 stat = hwif->INB(IDE_STATUS_REG);