Patchwork [09/20] pata_oldpiix: unify code for programming PIO and MWDMA timings

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Submitter Bartlomiej Zolnierkiewicz
Date Feb. 8, 2011, 12:24 p.m.
Message ID <20110208122438.19110.37982.sendpatchset@linux-mhg7.site>
Download mbox | patch
Permalink /patch/82306/
State Not Applicable
Delegated to: David Miller
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Comments

Bartlomiej Zolnierkiewicz - Feb. 8, 2011, 12:24 p.m.
From 30f6c60ad1e2f9c640352b74279fdf8a930847bf Mon Sep 17 00:00:00 2001
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Date: Tue, 8 Feb 2011 12:39:26 +0100
Subject: [PATCH 09/20] pata_oldpiix: unify code for programming PIO and MWDMA timings

Besides making things noticably simpler it results in ~12% decrease in
the driver LOC count and also ~5% decrease in the driver binary size
(as measured on x86-32).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
 drivers/ata/pata_oldpiix.c |   88 +++++++++++++------------------------------
 1 files changed, 27 insertions(+), 61 deletions(-)
Sergei Shtylyov - Feb. 20, 2011, 2:52 p.m.
Hello.

On 08-02-2011 15:24, Bartlomiej Zolnierkiewicz wrote:

>  From 30f6c60ad1e2f9c640352b74279fdf8a930847bf Mon Sep 17 00:00:00 2001
> From: Bartlomiej Zolnierkiewicz<bzolnier@gmail.com>
> Date: Tue, 8 Feb 2011 12:39:26 +0100
> Subject: [PATCH 09/20] pata_oldpiix: unify code for programming PIO and MWDMA timings

> Besides making things noticably simpler it results in ~12% decrease in
> the driver LOC count and also ~5% decrease in the driver binary size
> (as measured on x86-32).

> Signed-off-by: Bartlomiej Zolnierkiewicz<bzolnier@gmail.com>
[...]

> diff --git a/drivers/ata/pata_oldpiix.c b/drivers/ata/pata_oldpiix.c
> index b811c16..433d2fc 100644
> --- a/drivers/ata/pata_oldpiix.c
> +++ b/drivers/ata/pata_oldpiix.c
[...]
> @@ -82,14 +71,18 @@ static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
>   			    { 2, 1 },
>   			    { 2, 3 }, };
>
> -	if (pio>  1)
> +	if (pio > 1 || use_mwdma)

    'use_mwdma' check is superfluous...

>   		control |= 1;	/* TIME */
> -	if (ata_pio_need_iordy(adev))
> +	if (ata_pio_need_iordy(adev) || use_mwdma)
>   		control |= 2;	/* IE */
> -
>   	/* Intel specifies that the prefetch/posting is for disk only */
>   	if (adev->class == ATA_DEV_ATA)
>   		control |= 4;	/* PPE */
> +	/* If the drive MWDMA is faster than it can do PIO then
> +	   we must force PIO into PIO0 */

    Please fix the comment style.

> +	if (use_mwdma && adev->pio_mode < (XFER_PIO_0 + pio))

    Parens not needed around +.

> +		/* Enable DMA timing only */
> +		control |= 8;	/* PIO cycles in PIO0 */
>
>   	pci_read_config_word(dev, idetm_port,&idetm_data);
>
> @@ -113,6 +106,22 @@ static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
>   }
>
>   /**
> + *	oldpiix_set_piomode - Initialize host controller PATA PIO timings
> + *	@ap: Port whose timings we are configuring
> + *	@adev: Device whose timings we are configuring
> + *
> + *	Set PIO mode for device, in host controller PCI config space.
> + *
> + *	LOCKING:
> + *	None (inherited from caller).
> + */
> +
> +static void oldpiix_set_piomode(struct ata_port *ap, struct ata_device *adev)
> +{
> +	oldpiix_set_timings(ap, adev, adev->pio_mode - XFER_PIO_0, 0);

    s/0/false/?

> +}
> +
> +/**
>    *	oldpiix_set_dmamode - Initialize host controller PATA DMA timings
>    *	@ap: Port whose timings we are configuring
>    *	@adev: Device to program
> @@ -125,58 +134,15 @@ static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
[...]
> +	oldpiix_set_timings(ap, adev, pio, 1);

    s/1/true/?

WBR, Sergei
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Patch

diff --git a/drivers/ata/pata_oldpiix.c b/drivers/ata/pata_oldpiix.c
index b811c16..433d2fc 100644
--- a/drivers/ata/pata_oldpiix.c
+++ b/drivers/ata/pata_oldpiix.c
@@ -50,20 +50,9 @@  static int oldpiix_pre_reset(struct ata_link *link, unsigned long deadline)
 	return ata_sff_prereset(link, deadline);
 }
 
-/**
- *	oldpiix_set_piomode - Initialize host controller PATA PIO timings
- *	@ap: Port whose timings we are configuring
- *	@adev: Device whose timings we are configuring
- *
- *	Set PIO mode for device, in host controller PCI config space.
- *
- *	LOCKING:
- *	None (inherited from caller).
- */
-
-static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
+static void oldpiix_set_timings(struct ata_port *ap, struct ata_device *adev,
+				u8 pio, bool use_mwdma)
 {
-	unsigned int pio	= adev->pio_mode - XFER_PIO_0;
 	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
 	unsigned int idetm_port= ap->port_no ? 0x42 : 0x40;
 	u16 idetm_data;
@@ -82,14 +71,18 @@  static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
 			    { 2, 1 },
 			    { 2, 3 }, };
 
-	if (pio > 1)
+	if (pio > 1 || use_mwdma)
 		control |= 1;	/* TIME */
-	if (ata_pio_need_iordy(adev))
+	if (ata_pio_need_iordy(adev) || use_mwdma)
 		control |= 2;	/* IE */
-
 	/* Intel specifies that the prefetch/posting is for disk only */
 	if (adev->class == ATA_DEV_ATA)
 		control |= 4;	/* PPE */
+	/* If the drive MWDMA is faster than it can do PIO then
+	   we must force PIO into PIO0 */
+	if (use_mwdma && adev->pio_mode < (XFER_PIO_0 + pio))
+		/* Enable DMA timing only */
+		control |= 8;	/* PIO cycles in PIO0 */
 
 	pci_read_config_word(dev, idetm_port, &idetm_data);
 
@@ -113,6 +106,22 @@  static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
 }
 
 /**
+ *	oldpiix_set_piomode - Initialize host controller PATA PIO timings
+ *	@ap: Port whose timings we are configuring
+ *	@adev: Device whose timings we are configuring
+ *
+ *	Set PIO mode for device, in host controller PCI config space.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+
+static void oldpiix_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	oldpiix_set_timings(ap, adev, adev->pio_mode - XFER_PIO_0, 0);
+}
+
+/**
  *	oldpiix_set_dmamode - Initialize host controller PATA DMA timings
  *	@ap: Port whose timings we are configuring
  *	@adev: Device to program
@@ -125,58 +134,15 @@  static void oldpiix_set_piomode (struct ata_port *ap, struct ata_device *adev)
 
 static void oldpiix_set_dmamode (struct ata_port *ap, struct ata_device *adev)
 {
-	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
-	u8 idetm_port		= ap->port_no ? 0x42 : 0x40;
-	u16 idetm_data;
-
-	static const	 /* ISP  RTC */
-	u8 timings[][2]	= { { 0, 0 },
-			    { 0, 0 },
-			    { 1, 0 },
-			    { 2, 1 },
-			    { 2, 3 }, };
-
-	/*
-	 * MWDMA is driven by the PIO timings. We must also enable
-	 * IORDY unconditionally along with TIME1. PPE has already
-	 * been set when the PIO timing was set.
-	 */
+	/* MWDMA is driven by the PIO timings. */
 
 	unsigned int mwdma	= adev->dma_mode - XFER_MW_DMA_0;
-	unsigned int control;
 	const unsigned int needed_pio[3] = {
 		XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
 	};
 	int pio = needed_pio[mwdma] - XFER_PIO_0;
 
-	pci_read_config_word(dev, idetm_port, &idetm_data);
-
-	control = 3;	/* IORDY|TIME0 */
-	/* Intel specifies that the PPE functionality is for disk only */
-	if (adev->class == ATA_DEV_ATA)
-		control |= 4;	/* PPE enable */
-
-	/* If the drive MWDMA is faster than it can do PIO then
-	   we must force PIO into PIO0 */
-
-	if (adev->pio_mode < needed_pio[mwdma])
-		/* Enable DMA timing only */
-		control |= 8;	/* PIO cycles in PIO0 */
-
-	/* Mask out the relevant control and timing bits we will load. Also
-	   clear the other drive TIME register as a precaution */
-	if (adev->devno == 0) {
-		idetm_data &= 0xCCE0;
-		idetm_data |= control;
-	} else {
-		idetm_data &= 0xCC0E;
-		idetm_data |= (control << 4);
-	}
-	idetm_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8);
-	pci_write_config_word(dev, idetm_port, idetm_data);
-
-	/* Track which port is configured */
-	ap->private_data = adev;
+	oldpiix_set_timings(ap, adev, pio, 1);
 }
 
 /**