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: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

27 files changed, 236 insertions, 574 deletions

diff --git a/drivers/ide/arm/icside.c b/drivers/ide/arm/icside.c
index e2953fc1faf..f383ace2a08 100644
--- a/drivers/ide/arm/icside.c
+++ b/drivers/ide/arm/icside.c
@@ -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;
 	}
 
diff --git a/drivers/ide/cris/ide-cris.c b/drivers/ide/cris/ide-cris.c
index 5e8efc89255..9691d089fce 100644
--- a/drivers/ide/cris/ide-cris.c
+++ b/drivers/ide/cris/ide-cris.c
@@ -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;
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index fd213088b06..f28fabb791f 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -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;
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 3caa176b315..ed6128f6cd9 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -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) &&
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 68719314df3..4557fc5a3ea 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -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 */
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index c06424fe647..73f752142f9 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -477,6 +477,7 @@ static void ide_hwif_restore(ide_hwif_t *hwif, ide_hwif_t *tmp_hwif)
 
 	hwif->tuneproc			= tmp_hwif->tuneproc;
 	hwif->speedproc			= tmp_hwif->speedproc;
+	hwif->udma_filter		= tmp_hwif->udma_filter;
 	hwif->selectproc		= tmp_hwif->selectproc;
 	hwif->reset_poll		= tmp_hwif->reset_poll;
 	hwif->pre_reset			= tmp_hwif->pre_reset;
diff --git a/drivers/ide/pci/aec62xx.c b/drivers/ide/pci/aec62xx.c
index abe0b1bb55f..099539e8c7a 100644
--- a/drivers/ide/pci/aec62xx.c
+++ b/drivers/ide/pci/aec62xx.c
@@ -87,38 +87,12 @@ static u8 pci_bus_clock_list_ultra (u8 speed, struct chipset_bus_clock_list_entr
 	return chipset_table->ultra_settings;
 }
 
-static u8 aec62xx_ratemask (ide_drive_t *drive)
-{
-	ide_hwif_t *hwif	= HWIF(drive);
-	u8 mode;
-
-	switch(hwif->pci_dev->device) {
-		case PCI_DEVICE_ID_ARTOP_ATP865:
-		case PCI_DEVICE_ID_ARTOP_ATP865R:
-			mode = (inb(hwif->channel ?
-				    hwif->mate->dma_status :
-				    hwif->dma_status) & 0x10) ? 4 : 3;
-			break;
-		case PCI_DEVICE_ID_ARTOP_ATP860:
-		case PCI_DEVICE_ID_ARTOP_ATP860R:
-			mode = 2;
-			break;
-		case PCI_DEVICE_ID_ARTOP_ATP850UF:
-		default:
-			return 1;
-	}
-
-	if (!eighty_ninty_three(drive))
-		mode = min(mode, (u8)1);
-	return mode;
-}
-
 static int aec6210_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev *dev	= hwif->pci_dev;
 	u16 d_conf		= 0;
-	u8 speed	= ide_rate_filter(aec62xx_ratemask(drive), xferspeed);
+	u8 speed		= ide_rate_filter(drive, xferspeed);
 	u8 ultra = 0, ultra_conf = 0;
 	u8 tmp0 = 0, tmp1 = 0, tmp2 = 0;
 	unsigned long flags;
@@ -145,7 +119,7 @@ static int aec6260_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev *dev	= hwif->pci_dev;
-	u8 speed	= ide_rate_filter(aec62xx_ratemask(drive), xferspeed);
+	u8 speed	= ide_rate_filter(drive, xferspeed);
 	u8 unit		= (drive->select.b.unit & 0x01);
 	u8 tmp1 = 0, tmp2 = 0;
 	u8 ultra = 0, drive_conf = 0, ultra_conf = 0;
@@ -183,7 +157,7 @@ static int aec62xx_tune_chipset (ide_drive_t *drive, u8 speed)
 
 static int config_chipset_for_dma (ide_drive_t *drive)
 {
-	u8 speed = ide_dma_speed(drive, aec62xx_ratemask(drive));	
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!(speed))
 		return 0;
diff --git a/drivers/ide/pci/alim15x3.c b/drivers/ide/pci/alim15x3.c
index 26c27d946c6..76643b626bd 100644
--- a/drivers/ide/pci/alim15x3.c
+++ b/drivers/ide/pci/alim15x3.c
@@ -378,74 +378,31 @@ static void ali15x3_tune_drive (ide_drive_t *drive, u8 pio)
 }
 
 /**
- *	ali15x3_can_ultra	-	check for ultra DMA support
- *	@drive: drive to do the check
+ *	ali_udma_filter		-	compute UDMA mask
+ *	@drive: IDE device
  *
- *	Check the drive and controller revisions. Return 0 if UDMA is
- *	not available, or 1 if UDMA can be used. The actual rules for
- *	the ALi are
+ *	Return available UDMA modes.
+ *
+ *	The actual rules for the ALi are:
  *		No UDMA on revisions <= 0x20
  *		Disk only for revisions < 0xC2
  *		Not WDC drives for revisions < 0xC2
  *
  *	FIXME: WDC ifdef needs to die
  */
- 
-static u8 ali15x3_can_ultra (ide_drive_t *drive)
-{
-#ifndef CONFIG_WDC_ALI15X3
-	struct hd_driveid *id	= drive->id;
-#endif /* CONFIG_WDC_ALI15X3 */
-
-	if (m5229_revision <= 0x20) {
-		return 0;
-	} else if ((m5229_revision < 0xC2) &&
-#ifndef CONFIG_WDC_ALI15X3
-		   ((chip_is_1543c_e && strstr(id->model, "WDC ")) ||
-		    (drive->media!=ide_disk))) {
-#else /* CONFIG_WDC_ALI15X3 */
-		   (drive->media!=ide_disk)) {
-#endif /* CONFIG_WDC_ALI15X3 */
-		return 0;
-	} else {
-		return 1;
-	}
-}
 
-/**
- *	ali15x3_ratemask	-	generate DMA mode list
- *	@drive: drive to compute against
- *
- *	Generate a list of the available DMA modes for the drive. 
- *	FIXME: this function contains lots of bogus masking we can dump
- *
- *	Return the highest available mode (UDMA33, UDMA66, UDMA100,..)
- */
- 
-static u8 ali15x3_ratemask (ide_drive_t *drive)
+static u8 ali_udma_filter(ide_drive_t *drive)
 {
-	u8 mode = 0, can_ultra	= ali15x3_can_ultra(drive);
-
-	if (m5229_revision > 0xC4 && can_ultra) {
-		mode = 4;
-	} else if (m5229_revision == 0xC4 && can_ultra) {
-		mode = 3;
-	} else if (m5229_revision >= 0xC2 && can_ultra) {
-		mode = 2;
-	} else if (can_ultra) {
-		return 1;
-	} else {
-		return 0;
+	if (m5229_revision > 0x20 && m5229_revision < 0xC2) {
+		if (drive->media != ide_disk)
+			return 0;
+#ifndef CONFIG_WDC_ALI15X3
+		if (chip_is_1543c_e && strstr(drive->id->model, "WDC "))
+			return 0;
+#endif
 	}
 
-	/*
-	 *	If the drive sees no suitable cable then UDMA 33
-	 *	is the highest permitted mode
-	 */
-	 
-	if (!eighty_ninty_three(drive))
-		mode = min(mode, (u8)1);
-	return mode;
+	return drive->hwif->ultra_mask;
 }
 
 /**
@@ -461,7 +418,7 @@ static int ali15x3_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev *dev	= hwif->pci_dev;
-	u8 speed		= ide_rate_filter(ali15x3_ratemask(drive), xferspeed);
+	u8 speed		= ide_rate_filter(drive, xferspeed);
 	u8 speed1		= speed;
 	u8 unit			= (drive->select.b.unit & 0x01);
 	u8 tmpbyte		= 0x00;
@@ -511,7 +468,7 @@ static int ali15x3_tune_chipset (ide_drive_t *drive, u8 xferspeed)
  
 static int config_chipset_for_dma (ide_drive_t *drive)
 {
-	u8 speed = ide_dma_speed(drive, ali15x3_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!(speed))
 		return 0;
@@ -771,6 +728,7 @@ static void __devinit init_hwif_common_ali15x3 (ide_hwif_t *hwif)
 	hwif->autodma = 0;
 	hwif->tuneproc = &ali15x3_tune_drive;
 	hwif->speedproc = &ali15x3_tune_chipset;
+	hwif->udma_filter = &ali_udma_filter;
 
 	/* don't use LBA48 DMA on ALi devices before rev 0xC5 */
 	hwif->no_lba48_dma = (m5229_revision <= 0xC4) ? 1 : 0;
diff --git a/drivers/ide/pci/atiixp.c b/drivers/ide/pci/atiixp.c
index 2d48af32e3f..f7e80d6076d 100644
--- a/drivers/ide/pci/atiixp.c
+++ b/drivers/ide/pci/atiixp.c
@@ -49,22 +49,6 @@ static int save_mdma_mode[4];
 static DEFINE_SPINLOCK(atiixp_lock);
 
 /**
- *	atiixp_ratemask		-	compute rate mask for ATIIXP IDE
- *	@drive: IDE drive to compute for
- *
- *	Returns the available modes for the ATIIXP IDE controller.
- */
-
-static u8 atiixp_ratemask(ide_drive_t *drive)
-{
-	u8 mode = 3;
-
-	if (!eighty_ninty_three(drive))
-		mode = min(mode, (u8)1);
-	return mode;
-}
-
-/**
  *	atiixp_dma_2_pio		-	return the PIO mode matching DMA
  *	@xfer_rate: transfer speed
  *
@@ -189,7 +173,7 @@ static int atiixp_speedproc(ide_drive_t *drive, u8 xferspeed)
 	u16 tmp16;
 	u8 speed, pio;
 
-	speed = ide_rate_filter(atiixp_ratemask(drive), xferspeed);
+	speed = ide_rate_filter(drive, xferspeed);
 
 	spin_lock_irqsave(&atiixp_lock, flags);
 
@@ -233,7 +217,7 @@ static int atiixp_speedproc(ide_drive_t *drive, u8 xferspeed)
 
 static int atiixp_config_drive_for_dma(ide_drive_t *drive)
 {
-	u8 speed = ide_dma_speed(drive, atiixp_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!speed)
 		return 0;
diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index 610c45f7b4e..19f5ac1f866 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -292,55 +292,6 @@ static void cmd64x_tune_drive (ide_drive_t *drive, u8 pio)
 	(void) ide_config_drive_speed(drive, XFER_PIO_0 + pio);
 }
 
-static u8 cmd64x_ratemask (ide_drive_t *drive)
-{
-	struct pci_dev *dev	= HWIF(drive)->pci_dev;
-	u8 mode = 0;
-
-	switch(dev->device) {
-		case PCI_DEVICE_ID_CMD_649:
-			mode = 3;
-			break;
-		case PCI_DEVICE_ID_CMD_648:
-			mode = 2;
-			break;
-		case PCI_DEVICE_ID_CMD_643:
-			return 0;
-
-		case PCI_DEVICE_ID_CMD_646:
-		{
-			unsigned int class_rev	= 0;
-			pci_read_config_dword(dev,
-				PCI_CLASS_REVISION, &class_rev);
-			class_rev &= 0xff;
-		/*
-		 * UltraDMA only supported on PCI646U and PCI646U2, which
-		 * correspond to revisions 0x03, 0x05 and 0x07 respectively.
-		 * Actually, although the CMD tech support people won't
-		 * tell me the details, the 0x03 revision cannot support
-		 * UDMA correctly without hardware modifications, and even
-		 * then it only works with Quantum disks due to some
-		 * hold time assumptions in the 646U part which are fixed
-		 * in the 646U2.
-		 *
-		 * So we only do UltraDMA on revision 0x05 and 0x07 chipsets.
-		 */
-			switch(class_rev) {
-				case 0x07:
-				case 0x05:
-					return 1;
-				case 0x03:
-				case 0x01:
-				default:
-					return 0;
-			}
-		}
-	}
-	if (!eighty_ninty_three(drive))
-		mode = min(mode, (u8)1);
-	return mode;
-}
-
 static int cmd64x_tune_chipset (ide_drive_t *drive, u8 speed)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
@@ -348,7 +299,7 @@ static int cmd64x_tune_chipset (ide_drive_t *drive, u8 speed)
 	u8 unit			= drive->dn & 0x01;
 	u8 regU = 0, pciU	= hwif->channel ? UDIDETCR1 : UDIDETCR0;
 
-	speed = ide_rate_filter(cmd64x_ratemask(drive), speed);
+	speed = ide_rate_filter(drive, speed);
 
 	if (speed >= XFER_SW_DMA_0) {
 		(void) pci_read_config_byte(dev, pciU, &regU);
@@ -403,7 +354,7 @@ static int cmd64x_tune_chipset (ide_drive_t *drive, u8 speed)
 
 static int config_chipset_for_dma (ide_drive_t *drive)
 {
-	u8 speed	= ide_dma_speed(drive, cmd64x_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!speed)
 		return 0;
@@ -646,6 +597,18 @@ static void __devinit init_hwif_cmd64x(ide_hwif_t *hwif)
 
 	hwif->ultra_mask = hwif->cds->udma_mask;
 
+	/*
+	 * UltraDMA only supported on PCI646U and PCI646U2, which
+	 * correspond to revisions 0x03, 0x05 and 0x07 respectively.
+	 * Actually, although the CMD tech support people won't
+	 * tell me the details, the 0x03 revision cannot support
+	 * UDMA correctly without hardware modifications, and even
+	 * then it only works with Quantum disks due to some
+	 * hold time assumptions in the 646U part which are fixed
+	 * in the 646U2.
+	 *
+	 * So we only do UltraDMA on revision 0x05 and 0x07 chipsets.
+	 */
 	if (dev->device == PCI_DEVICE_ID_CMD_646 && class_rev < 5)
 		hwif->ultra_mask = 0x00;
 
diff --git a/drivers/ide/pci/cs5535.c b/drivers/ide/pci/cs5535.c
index 45f43efbf92..66a101e470d 100644
--- a/drivers/ide/pci/cs5535.c
+++ b/drivers/ide/pci/cs5535.c
@@ -127,20 +127,6 @@ static void cs5535_set_speed(ide_drive_t *drive, u8 speed)
 	}
 }
 
-static u8 cs5535_ratemask(ide_drive_t *drive)
-{
-	/* eighty93 will return 1 if it's 80core and capable of
-	exceeding udma2, 0 otherwise. we need ratemask to set
-	the max speed and if we can > udma2 then we return 2
-	which selects speed_max as udma4 which is the 5535's max
-	speed, and 1 selects udma2 which is the max for 40c */
-	if (!eighty_ninty_three(drive))
-		return 1;
-
-	return 2;
-}
-
-
 /****
  *	cs5535_set_drive         -     Configure the drive to the new speed
  *	@drive: Drive to set up
@@ -151,7 +137,7 @@ static u8 cs5535_ratemask(ide_drive_t *drive)
  */
 static int cs5535_set_drive(ide_drive_t *drive, u8 speed)
 {
-	speed = ide_rate_filter(cs5535_ratemask(drive), speed);
+	speed = ide_rate_filter(drive, speed);
 	ide_config_drive_speed(drive, speed);
 	cs5535_set_speed(drive, speed);
 
@@ -180,9 +166,7 @@ static void cs5535_tuneproc(ide_drive_t *drive, u8 xferspeed)
 
 static int cs5535_config_drive_for_dma(ide_drive_t *drive)
 {
-	u8 speed;
-
-	speed = ide_dma_speed(drive, cs5535_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	/* If no DMA speed was available then let dma_check hit pio */
 	if (!speed) {
diff --git a/drivers/ide/pci/hpt34x.c b/drivers/ide/pci/hpt34x.c
index 924eaa3a570..473e1b33dbf 100644
--- a/drivers/ide/pci/hpt34x.c
+++ b/drivers/ide/pci/hpt34x.c
@@ -43,15 +43,10 @@
 
 #define HPT343_DEBUG_DRIVE_INFO		0
 
-static u8 hpt34x_ratemask (ide_drive_t *drive)
-{
-	return 1;
-}
-
 static int hpt34x_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 {
 	struct pci_dev *dev	= HWIF(drive)->pci_dev;
-	u8 speed	= ide_rate_filter(hpt34x_ratemask(drive), xferspeed);
+	u8 speed = ide_rate_filter(drive, xferspeed);
 	u32 reg1= 0, tmp1 = 0, reg2 = 0, tmp2 = 0;
 	u8			hi_speed, lo_speed;
 
@@ -98,7 +93,7 @@ static void hpt34x_tune_drive (ide_drive_t *drive, u8 pio)
 
 static int config_chipset_for_dma (ide_drive_t *drive)
 {
-	u8 speed = ide_dma_speed(drive, hpt34x_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!(speed))
 		return 0;
diff --git a/drivers/ide/pci/hpt366.c b/drivers/ide/pci/hpt366.c
index cf9d344d19f..de5ad9c35dc 100644
--- a/drivers/ide/pci/hpt366.c
+++ b/drivers/ide/pci/hpt366.c
@@ -514,43 +514,31 @@ static int check_in_drive_list(ide_drive_t *drive, const char **list)
 	return 0;
 }
 
-static u8 hpt3xx_ratemask(ide_drive_t *drive)
-{
-	struct hpt_info *info	= pci_get_drvdata(HWIF(drive)->pci_dev);
-	u8 mode			= info->max_mode;
-
-	if (!eighty_ninty_three(drive) && mode)
-		mode = min(mode, (u8)1);
-	return mode;
-}
-
 /*
  *	Note for the future; the SATA hpt37x we must set
  *	either PIO or UDMA modes 0,4,5
  */
- 
-static u8 hpt3xx_ratefilter(ide_drive_t *drive, u8 speed)
+
+static u8 hpt3xx_udma_filter(ide_drive_t *drive)
 {
 	struct hpt_info *info	= pci_get_drvdata(HWIF(drive)->pci_dev);
 	u8 chip_type		= info->chip_type;
-	u8 mode			= hpt3xx_ratemask(drive);
-
-	if (drive->media != ide_disk)
-		return min(speed, (u8)XFER_PIO_4);
+	u8 mode			= info->max_mode;
+	u8 mask;
 
 	switch (mode) {
 		case 0x04:
-			speed = min_t(u8, speed, XFER_UDMA_6);
+			mask = 0x7f;
 			break;
 		case 0x03:
-			speed = min_t(u8, speed, XFER_UDMA_5);
+			mask = 0x3f;
 			if (chip_type >= HPT374)
 				break;
 			if (!check_in_drive_list(drive, bad_ata100_5))
 				goto check_bad_ata33;
 			/* fall thru */
 		case 0x02:
-			speed = min_t(u8, speed, XFER_UDMA_4);
+			mask = 0x1f;
 
 			/*
 			 * CHECK ME, Does this need to be changed to HPT374 ??
@@ -561,13 +549,13 @@ static u8 hpt3xx_ratefilter(ide_drive_t *drive, u8 speed)
 			    !check_in_drive_list(drive, bad_ata66_4))
 				goto check_bad_ata33;
 
-			speed = min_t(u8, speed, XFER_UDMA_3);
+			mask = 0x0f;
 			if (HPT366_ALLOW_ATA66_3 &&
 			    !check_in_drive_list(drive, bad_ata66_3))
 				goto check_bad_ata33;
 			/* fall thru */
 		case 0x01:
-			speed = min_t(u8, speed, XFER_UDMA_2);
+			mask = 0x07;
 
 		check_bad_ata33:
 			if (chip_type >= HPT370A)
@@ -577,10 +565,10 @@ static u8 hpt3xx_ratefilter(ide_drive_t *drive, u8 speed)
 			/* fall thru */
 		case 0x00:
 		default:
-			speed = min_t(u8, speed, XFER_MW_DMA_2);
+			mask = 0x00;
 			break;
 	}
-	return speed;
+	return mask;
 }
 
 static u32 get_speed_setting(u8 speed, struct hpt_info *info)
@@ -608,12 +596,19 @@ static int hpt36x_tune_chipset(ide_drive_t *drive, u8 xferspeed)
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev  *dev	= hwif->pci_dev;
 	struct hpt_info	*info	= pci_get_drvdata(dev);
-	u8  speed		= hpt3xx_ratefilter(drive, xferspeed);
+	u8  speed		= ide_rate_filter(drive, xferspeed);
 	u8  itr_addr		= drive->dn ? 0x44 : 0x40;
-	u32 itr_mask		= speed < XFER_MW_DMA_0 ? 0x30070000 :
-				 (speed < XFER_UDMA_0   ? 0xc0070000 : 0xc03800ff);
-	u32 new_itr		= get_speed_setting(speed, info);
 	u32 old_itr		= 0;
+	u32 itr_mask, new_itr;
+
+	/* TODO: move this to ide_rate_filter() [ check ->atapi_dma ] */
+	if (drive->media != ide_disk)
+		speed = min_t(u8, speed, XFER_PIO_4);
+
+	itr_mask = speed < XFER_MW_DMA_0 ? 0x30070000 :
+		  (speed < XFER_UDMA_0   ? 0xc0070000 : 0xc03800ff);
+
+	new_itr = get_speed_setting(speed, info);
 
 	/*
 	 * Disable on-chip PIO FIFO/buffer (and PIO MST mode as well)
@@ -633,12 +628,19 @@ static int hpt37x_tune_chipset(ide_drive_t *drive, u8 xferspeed)
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev  *dev	= hwif->pci_dev;
 	struct hpt_info	*info	= pci_get_drvdata(dev);
-	u8  speed		= hpt3xx_ratefilter(drive, xferspeed);
+	u8  speed		= ide_rate_filter(drive, xferspeed);
 	u8  itr_addr		= 0x40 + (drive->dn * 4);
-	u32 itr_mask		= speed < XFER_MW_DMA_0 ? 0x303c0000 :
-				 (speed < XFER_UDMA_0   ? 0xc03c0000 : 0xc1c001ff);
-	u32 new_itr		= get_speed_setting(speed, info);
 	u32 old_itr		= 0;
+	u32 itr_mask, new_itr;
+
+	/* TODO: move this to ide_rate_filter() [ check ->atapi_dma ] */
+	if (drive->media != ide_disk)
+		speed = min_t(u8, speed, XFER_PIO_4);
+
+	itr_mask = speed < XFER_MW_DMA_0 ? 0x303c0000 :
+		  (speed < XFER_UDMA_0   ? 0xc03c0000 : 0xc1c001ff);
+
+	new_itr = get_speed_setting(speed, info);
 
 	pci_read_config_dword(dev, itr_addr, &old_itr);
 	new_itr = (new_itr & ~itr_mask) | (old_itr & itr_mask);
@@ -676,7 +678,7 @@ static void hpt3xx_tune_drive(ide_drive_t *drive, u8 pio)
  */
 static int config_chipset_for_dma(ide_drive_t *drive)
 {
-	u8 speed = ide_dma_speed(drive, hpt3xx_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!speed)
 		return 0;
@@ -1271,6 +1273,7 @@ static void __devinit init_hwif_hpt366(ide_hwif_t *hwif)
 	hwif->intrproc			= &hpt3xx_intrproc;
 	hwif->maskproc			= &hpt3xx_maskproc;
 	hwif->busproc			= &hpt3xx_busproc;
+	hwif->udma_filter		= &hpt3xx_udma_filter;
 
 	/*
 	 * HPT3xxN chips have some complications:
diff --git a/drivers/ide/pci/it8213.c b/drivers/ide/pci/it8213.c
index 424f00bb160..02b56cb7bb1 100644
--- a/drivers/ide/pci/it8213.c
+++ b/drivers/ide/pci/it8213.c
@@ -17,22 +17,6 @@
 
 #include <asm/io.h>
 
-/*
- *	it8213_ratemask	-	Compute available modes
- *	@drive: IDE drive
- *
- *	Compute the available speeds for the devices on the interface. This
- *	is all modes to ATA133 clipped by drive cable setup.
- */
-
-static u8 it8213_ratemask (ide_drive_t *drive)
-{
-	u8 mode	= 4;
-	if (!eighty_ninty_three(drive))
-		mode = min_t(u8, mode, 1);
-	return mode;
-}
-
 /**
  *	it8213_dma_2_pio		-	return the PIO mode matching DMA
  *	@xfer_rate: transfer speed
@@ -145,7 +129,7 @@ static int it8213_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 	ide_hwif_t *hwif	= HWIF(drive);
 	struct pci_dev *dev	= hwif->pci_dev;
 	u8 maslave		= 0x40;
-	u8 speed		= ide_rate_filter(it8213_ratemask(drive), xferspeed);
+	u8 speed		= ide_rate_filter(drive, xferspeed);
 	int a_speed		= 3 << (drive->dn * 4);
 	int u_flag		= 1 << drive->dn;
 	int v_flag		= 0x01 << drive->dn;
@@ -222,7 +206,7 @@ static int it8213_tune_chipset (ide_drive_t *drive, u8 xferspeed)
 
 static int config_chipset_for_dma (ide_drive_t *drive)
 {
-	u8 speed = ide_dma_speed(drive, it8213_ratemask(drive));
+	u8 speed = ide_max_dma_mode(drive);
 
 	if (!speed)
 		return 0;
diff --git a/drivers/ide/pci/it821x.c b/drivers/ide/pci/it821x.c
index 4e1254813ee..442f658c6ae 100644
--- a/drivers/ide/pci/it821x.c
+++ b/drivers/ide/pci/it821x.c
@@ -229,22 +229,6 @@ static void it821x_clock_strategy(ide_drive_t *drive)
 }
 
 /**
- *	it821x_ratemask	-	Compute available modes
- *	@drive: IDE drive