Commit 2d5eaa6d authored by Bartlomiej Zolnierkiewicz's avatar Bartlomiej Zolnierkiewicz
Browse files

ide: rework the code for selecting the best DMA transfer mode (v3) 



Depends on the "ide: fix UDMA/MWDMA/SWDMA masks" patch.

* add ide_hwif_t.udma_filter hook for filtering UDMA mask
  (use it in alim15x3, hpt366, siimage and serverworks drivers)
* add ide_max_dma_mode() for finding best DMA mode for the device
  (loosely based on some older libata-core.c code)
* convert ide_dma_speed() users to use ide_max_dma_mode()
* make ide_rate_filter() take "ide_drive_t *drive" as an argument instead
  of "u8 mode" and teach it to how to use UDMA mask to do filtering
* use ide_rate_filter() in hpt366 driver
* remove no longer needed ide_dma_speed() and *_ratemask()
* unexport eighty_ninty_three()

v2:
* rename ->filter_udma_mask to ->udma_filter
  [ Suggested by Sergei Shtylyov <sshtylyov@ru.mvista.com>. ]

v3:
* updated for scc_pata driver (fixes XFER_UDMA_6 filtering for user-space
  originated transfer mode change requests when 100MHz clock is used)

Signed-off-by: default avatarBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
parent 18137207

drivers/ide/arm/icside.c

+1 −1
Original line number Diff line number Diff line
@@ -342,7 +342,7 @@ static int icside_dma_check(ide_drive_t *drive) 
	 * Enable DMA on any drive that has multiword DMA

	 */

	if (id->field_valid & 2) {

		xfer_mode = ide_dma_speed(drive, 0);

		xfer_mode = ide_max_dma_mode(drive);

		goto out;

	}

drivers/ide/cris/ide-cris.c

+1 −1
Original line number Diff line number Diff line
@@ -1004,7 +1004,7 @@ static int cris_ide_build_dmatable (ide_drive_t *drive) 


static int cris_config_drive_for_dma (ide_drive_t *drive)

{

	u8 speed = ide_dma_speed(drive, 1);

	u8 speed = ide_max_dma_mode(drive);



	if (!speed)

		return 0;

drivers/ide/ide-dma.c

+74 −0
Original line number Diff line number Diff line
@@ -705,6 +705,80 @@ int ide_use_dma(ide_drive_t *drive) 


EXPORT_SYMBOL_GPL(ide_use_dma);



static const u8 xfer_mode_bases[] = {

	XFER_UDMA_0,

	XFER_MW_DMA_0,

	XFER_SW_DMA_0,

};



static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)

{

	struct hd_driveid *id = drive->id;

	ide_hwif_t *hwif = drive->hwif;

	unsigned int mask = 0;



	switch(base) {

	case XFER_UDMA_0:

		if ((id->field_valid & 4) == 0)

			break;



		mask = id->dma_ultra & hwif->ultra_mask;



		if (hwif->udma_filter)

			mask &= hwif->udma_filter(drive);



		if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))

			mask &= 0x07;

		break;

	case XFER_MW_DMA_0:

		mask = id->dma_mword & hwif->mwdma_mask;

		break;

	case XFER_SW_DMA_0:

		mask = id->dma_1word & hwif->swdma_mask;

		break;

	default:

		BUG();

		break;

	}



	return mask;

}



/**

 *	ide_max_dma_mode	-	compute DMA speed

 *	@drive: IDE device

 *

 *	Checks the drive capabilities and returns the speed to use

 *	for the DMA transfer.  Returns 0 if the drive is incapable

 *	of DMA transfers.

 */



u8 ide_max_dma_mode(ide_drive_t *drive)

{

	ide_hwif_t *hwif = drive->hwif;

	unsigned int mask;

	int x, i;

	u8 mode = 0;



	if (drive->media != ide_disk && hwif->atapi_dma == 0)

		return 0;



	for (i = 0; i < ARRAY_SIZE(xfer_mode_bases); i++) {

		mask = ide_get_mode_mask(drive, xfer_mode_bases[i]);

		x = fls(mask) - 1;

		if (x >= 0) {

			mode = xfer_mode_bases[i] + x;

			break;

		}

	}



	printk(KERN_DEBUG "%s: selected mode 0x%x\n", drive->name, mode);



	return mode;

}



EXPORT_SYMBOL_GPL(ide_max_dma_mode);



void ide_dma_verbose(ide_drive_t *drive)

{

	struct hd_driveid *id	= drive->id;

drivers/ide/ide-iops.c

+0 −2
Original line number Diff line number Diff line
@@ -592,8 +592,6 @@ u8 eighty_ninty_three (ide_drive_t *drive) 
	return 1;

}



EXPORT_SYMBOL(eighty_ninty_three);



int ide_ata66_check (ide_drive_t *drive, ide_task_t *args)

{

	if ((args->tfRegister[IDE_COMMAND_OFFSET] == WIN_SETFEATURES) &&

drivers/ide/ide-lib.c

+18 −107
Original line number Diff line number Diff line
@@ -69,123 +69,34 @@ char *ide_xfer_verbose (u8 xfer_rate) 
EXPORT_SYMBOL(ide_xfer_verbose);



/**

 *	ide_dma_speed	-	compute DMA speed

 *	@drive: drive

 *	@mode:	modes available

 *

 *	Checks the drive capabilities and returns the speed to use

 *	for the DMA transfer.  Returns 0 if the drive is incapable

 *	of DMA transfers.

 */

 

u8 ide_dma_speed(ide_drive_t *drive, u8 mode)

{

	struct hd_driveid *id   = drive->id;

	ide_hwif_t *hwif	= HWIF(drive);

	u8 ultra_mask, mwdma_mask, swdma_mask;

	u8 speed = 0;



	if (drive->media != ide_disk && hwif->atapi_dma == 0)

		return 0;



	/* Capable of UltraDMA modes? */

	ultra_mask = id->dma_ultra & hwif->ultra_mask;



	if (!(id->field_valid & 4))

		mode = 0;	/* fallback to MW/SW DMA if no UltraDMA */



	switch (mode) {

	case 4:

		if (ultra_mask & 0x40) {

			speed = XFER_UDMA_6;

			break;

		}

	case 3:

		if (ultra_mask & 0x20) {

			speed = XFER_UDMA_5;

			break;

		}

	case 2:

		if (ultra_mask & 0x10) {

			speed = XFER_UDMA_4;

			break;

		}

		if (ultra_mask & 0x08) {

			speed = XFER_UDMA_3;

			break;

		}

	case 1:

		if (ultra_mask & 0x04) {

			speed = XFER_UDMA_2;

			break;

		}

		if (ultra_mask & 0x02) {

			speed = XFER_UDMA_1;

			break;

		}

		if (ultra_mask & 0x01) {

			speed = XFER_UDMA_0;

			break;

		}

	case 0:

		mwdma_mask = id->dma_mword & hwif->mwdma_mask;



		if (mwdma_mask & 0x04) {

			speed = XFER_MW_DMA_2;

			break;

		}

		if (mwdma_mask & 0x02) {

			speed = XFER_MW_DMA_1;

			break;

		}

		if (mwdma_mask & 0x01) {

			speed = XFER_MW_DMA_0;

			break;

		}



		swdma_mask = id->dma_1word & hwif->swdma_mask;



		if (swdma_mask & 0x04) {

			speed = XFER_SW_DMA_2;

			break;

		}

		if (swdma_mask & 0x02) {

			speed = XFER_SW_DMA_1;

			break;

		}

		if (swdma_mask & 0x01) {

			speed = XFER_SW_DMA_0;

			break;

		}

	}



	return speed;

}

EXPORT_SYMBOL(ide_dma_speed);





/**

 *	ide_rate_filter		-	return best speed for mode

 *	@mode: modes available

 *	ide_rate_filter		-	filter transfer mode

 *	@drive: IDE device

 *	@speed: desired speed

 *

 *	Given the available DMA/UDMA mode this function returns

 *	Given the available transfer modes this function returns

 *	the best available speed at or below the speed requested.

 *

 *	FIXME: filter also PIO/SWDMA/MWDMA modes

 */



u8 ide_rate_filter (u8 mode, u8 speed) 

u8 ide_rate_filter(ide_drive_t *drive, u8 speed)

{

#ifdef CONFIG_BLK_DEV_IDEDMA

	static u8 speed_max[] = {

		XFER_MW_DMA_2, XFER_UDMA_2, XFER_UDMA_4,

		XFER_UDMA_5, XFER_UDMA_6

	};

	ide_hwif_t *hwif = drive->hwif;

	u8 mask = hwif->ultra_mask, mode = XFER_MW_DMA_2;



	if (hwif->udma_filter)

		mask = hwif->udma_filter(drive);



	if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))

		mask &= 0x07;



	if (mask)

		mode = fls(mask) - 1 + XFER_UDMA_0;



//	printk("%s: mode 0x%02x, speed 0x%02x\n", __FUNCTION__, mode, speed);



	/* So that we remember to update this if new modes appear */

	BUG_ON(mode > 4);

	return min(speed, speed_max[mode]);

	return min(speed, mode);

#else /* !CONFIG_BLK_DEV_IDEDMA */

	return min(speed, (u8)XFER_PIO_4);

#endif /* CONFIG_BLK_DEV_IDEDMA */

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