Re: [PATCH 14/15] ide: rework the code for selecting the best DMA transfer mode

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello.

Bartlomiej Zolnierkiewicz wrote:

[PATCH] ide: rework the code for selecting the best DMA transfer mode

   Here's another portion of comments...

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

* add ide_hwif_t.filter_udma_mask hook for filtering UDMA mask

Erm, maybe a shorter method name like udma_filter would go with the others better. But well, that's my taste. :-)

  (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()

Index: b/drivers/ide/ide-dma.c
===================================================================
--- 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->filter_udma_mask)
+			mask &= hwif->filter_udma_mask(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);
+

   I didn't quite like the array/loop approach but well, that's my taste (I'd
rather put the mode-from-mask evaluation to the function and call it thrice)...

Index: b/drivers/ide/ide-lib.c
===================================================================
--- 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)

[...]

-EXPORT_SYMBOL(ide_dma_speed);

   Alas, my ide_dma_speed() fix is going to be oudated rather quickly... :-)

Index: b/drivers/ide/pci/hpt366.c
===================================================================
--- a/drivers/ide/pci/hpt366.c
+++ b/drivers/ide/pci/hpt366.c
@@ -513,43 +513,31 @@ static int check_in_drive_list(ide_drive
 	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_filter_udma_mask(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 ??
@@ -560,13 +548,13 @@ static u8 hpt3xx_ratefilter(ide_drive_t !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)
@@ -576,10 +564,10 @@ static u8 hpt3xx_ratefilter(ide_drive_t /* fall thru */
 		case 0x00:
 		default:
-			speed = min_t(u8, speed, XFER_MW_DMA_2);
+			mask = 0x00;
 			break;
 	}
-	return speed;
+	return mask;
 }

Erm, I see. This driver will need some redesign because 'struct hpt_info' was fitted for the old rate filtering model. Looks like the 'max_mode' field should be replaced by 'ultra_mask' there...

 static u32 get_speed_setting(u8 speed, struct hpt_info *info)
@@ -607,12 +595,19 @@ static int hpt36x_tune_chipset(ide_drive
 	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);
+

When I think about it, it seems quite stupid to set a PIO mode instead of a requested DMA one. So, this is actually a questionable piece of code in this driver...

Well, I must note the sorrow fact that both the IDE susbsytem as a whole doesn't keep track of PIO/DMA modes separately (having only current_mode) and the many drivers also fail to handle the timing registers shared by PIO/DMA modes correctly (well, it's actually also a hardware design issue :-).

+	itr_mask = speed < XFER_MW_DMA_0 ? 0x30070000 :
+		  (speed < XFER_UDMA_0   ? 0xc0070000 : 0xc03800ff);
+
+	new_itr = get_speed_setting(speed, info);

Well, I liked this code where it was. But anyway, it's going to be replaced RSN...

@@ -632,12 +627,19 @@ static int hpt37x_tune_chipset(ide_drive
 	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);

   Same comments here...

Index: b/drivers/ide/pci/serverworks.c
===================================================================
--- a/drivers/ide/pci/serverworks.c
+++ b/drivers/ide/pci/serverworks.c
@@ -65,16 +65,16 @@ static int check_in_drive_lists (ide_dri
 	return 0;
 }
-static u8 svwks_ratemask (ide_drive_t *drive)
+static u8 svwks_filter_udma_mask(ide_drive_t *drive)
 {
 	struct pci_dev *dev     = HWIF(drive)->pci_dev;
-	u8 mode = 0;
+	u8 mask = 0;

   Hm, this looks like it needs rework...

 	if (!svwks_revision)
 		pci_read_config_byte(dev, PCI_REVISION_ID, &svwks_revision);
if (dev->device == PCI_DEVICE_ID_SERVERWORKS_HT1000IDE)
-		return 2;
+		return 0x1f;
 	if (dev->device == PCI_DEVICE_ID_SERVERWORKS_OSB4IDE) {
 		u32 reg = 0;
 		if (isa_dev)
@@ -86,25 +86,31 @@ static u8 svwks_ratemask (ide_drive_t *d
 		if(drive->media == ide_disk)
 			return 0;
 		/* Check the OSB4 DMA33 enable bit */
-		return ((reg & 0x00004000) == 0x00004000) ? 1 : 0;
+		return ((reg & 0x00004000) == 0x00004000) ? 0x07 : 0;
 	} else if (svwks_revision < SVWKS_CSB5_REVISION_NEW) {
-		return 1;
+		return 0x07;
 	} else if (svwks_revision >= SVWKS_CSB5_REVISION_NEW) {
-		u8 btr = 0;
+		u8 btr = 0, mode;
 		pci_read_config_byte(dev, 0x5A, &btr);
 		mode = btr & 0x3;
-		if (!eighty_ninty_three(drive))
-			mode = min(mode, (u8)1);
+
 		/* If someone decides to do UDMA133 on CSB5 the same
 		   issue will bite so be inclusive */
 		if (mode > 2 && check_in_drive_lists(drive, svwks_bad_ata100))
 			mode = 2;
+
+		switch(mode) {
+		case 2:	 mask = 0x1f; break;
+		case 1:	 mask = 0x07; break;
+		default: mask = 0x00; break;
+		}
 	}
 	if (((dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE) ||
 	     (dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2)) &&
 	    (!(PCI_FUNC(dev->devfn) & 1)))
-		mode = 2;
-	return mode;
+		mask = 0x1f;
+
+	return mask;
 }

Hm, what was the problem with setting the proper masks based on PCI device ID in the init. code?
That'd have greatly simplified the filter...

Index: b/drivers/ide/pci/siimage.c
===================================================================
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -116,45 +116,41 @@ static inline unsigned long siimage_seld
 }
/**
- *	siimage_ratemask	-	Compute available modes
- *	@drive: IDE drive
+ *	sil_filter_udma_mask	-	compute UDMA mask
+ *	@drive: IDE device
+ *
+ *	Compute the available UDMA speeds for the device on the interface.
  *
- *	Compute the available speeds for the devices on the interface.
  *	For the CMD680 this depends on the clocking mode (scsc), for the
- *	SI3312 SATA controller life is a bit simpler. Enforce UDMA33
- *	as a limit if there is no 80pin cable present.
+ *	SI3112 SATA controller life is a bit simpler.
  */
- -static byte siimage_ratemask (ide_drive_t *drive)
+
+static u8 sil_filter_udma_mask(ide_drive_t *drive)
 {
-	ide_hwif_t *hwif	= HWIF(drive);
-	u8 mode	= 0, scsc = 0;
+	ide_hwif_t *hwif = drive->hwif;
 	unsigned long base = (unsigned long) hwif->hwif_data;
+	u8 mask = 0, scsc = 0;
if (hwif->mmio)
 		scsc = hwif->INB(base + 0x4A);
 	else
 		pci_read_config_byte(hwif->pci_dev, 0x8A, &scsc);
- if(is_sata(hwif))
-	{
-		if(strstr(drive->id->model, "Maxtor"))
-			return 3;
-		return 4;
+	if (is_sata(hwif)) {
+		mask = strstr(drive->id->model, "Maxtor") ? 0x3f : 0x7f;
+		goto out;
 	}
-	
+
 	if ((scsc & 0x30) == 0x10)	/* 133 */
-		mode = 4;
+		mask = 0x7f;
 	else if ((scsc & 0x30) == 0x20)	/* 2xPCI */
-		mode = 4;
+		mask = 0x7f;
 	else if ((scsc & 0x30) == 0x00)	/* 100 */
-		mode = 3;
+		mask = 0x3f;
 	else 	/* Disabled ? */
 		BUG();

   Most probably this is doable at init. time also...

MBR, Sergei

PS: I understand that the intent wasn not to make this rewrite optimal but
do it quick and with least affect. And I certainly may handle hpt366.c redesign... :-)

-
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux