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Subject[PATCH 04/20] pata_efar: unify code for programming PIO and MWDMA timings
From 2de7db4bcc16b7e95cca9ceb5921a6f620be76b7 Mon Sep 17 00:00:00 2001
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Date: Tue, 8 Feb 2011 12:39:25 +0100
Subject: [PATCH 04/20] pata_efar: unify code for programming PIO and MWDMA timings

Besides making things noticably simpler it results in ~10% decrease in
the driver LOC count and also ~8% decrease in the driver binary size
(as measured on x86-32).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
drivers/ata/pata_efar.c | 104 +++++++++++++++++------------------------------
1 files changed, 37 insertions(+), 67 deletions(-)

diff --git a/drivers/ata/pata_efar.c b/drivers/ata/pata_efar.c
index afe92b7..1e2ff7d 100644
--- a/drivers/ata/pata_efar.c
+++ b/drivers/ata/pata_efar.c
@@ -70,20 +70,9 @@ static int efar_cable_detect(struct ata_port *ap)

static DEFINE_SPINLOCK(efar_lock);

-/**
- * efar_set_piomode - Initialize host controller PATA PIO timings
- * @ap: Port whose timings we are configuring
- * @adev: Device to program
- *
- * Set PIO mode for device, in host controller PCI config space.
- *
- * LOCKING:
- * None (inherited from caller).
- */
-
-static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
+static void efar_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 long flags;
u8 master_port = ap->port_no ? 0x42 : 0x40;
@@ -103,13 +92,18 @@ static void efar_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)) /* PIO 3/4 require IORDY */
+ 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 */

spin_lock_irqsave(&efar_lock, flags);

@@ -145,6 +139,22 @@ static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
}

/**
+ * efar_set_piomode - Initialize host controller PATA PIO timings
+ * @ap: Port whose timings we are configuring
+ * @adev: Device to program
+ *
+ * Set PIO mode for device, in host controller PCI config space.
+ *
+ * LOCKING:
+ * None (inherited from caller).
+ */
+
+static void efar_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+ efar_set_timings(ap, adev, adev->pio_mode - XFER_PIO_0, 0);
+}
+
+/**
* efar_set_dmamode - Initialize host controller PATA DMA timings
* @ap: Port whose timings we are configuring
* @adev: Device to program
@@ -158,29 +168,19 @@ static void efar_set_piomode (struct ata_port *ap, struct ata_device *adev)
static void efar_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
struct pci_dev *dev = to_pci_dev(ap->host->dev);
- u8 master_port = ap->port_no ? 0x42 : 0x40;
- u16 master_data;
u8 speed = adev->dma_mode;
int devid = adev->devno + 2 * ap->port_no;
unsigned long flags;
u8 udma_enable;

- static const /* ISP RTC */
- u8 timings[][2] = { { 0, 0 },
- { 0, 0 },
- { 1, 0 },
- { 2, 1 },
- { 2, 3 }, };
-
- spin_lock_irqsave(&efar_lock, flags);
-
- pci_read_config_word(dev, master_port, &master_data);
- pci_read_config_byte(dev, 0x48, &udma_enable);
-
if (speed >= XFER_UDMA_0) {
- unsigned int udma = adev->dma_mode - XFER_UDMA_0;
+ unsigned int udma = speed - XFER_UDMA_0;
u16 udma_timing;

+ spin_lock_irqsave(&efar_lock, flags);
+
+ pci_read_config_byte(dev, 0x48, &udma_enable);
+
udma_enable |= (1 << devid);

/* Load the UDMA mode number */
@@ -188,50 +188,20 @@ static void efar_set_dmamode (struct ata_port *ap, struct ata_device *adev)
udma_timing &= ~(7 << (4 * devid));
udma_timing |= udma << (4 * devid);
pci_write_config_word(dev, 0x4A, udma_timing);
+
+ pci_write_config_byte(dev, 0x48, udma_enable);
+
+ spin_unlock_irqrestore(&efar_lock, flags);
} else {
- /*
- * 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.
- */
- unsigned int mwdma = adev->dma_mode - XFER_MW_DMA_0;
- unsigned int control;
- u8 slave_data;
+ /* MWDMA is driven by the PIO timings. */
+ unsigned int mwdma = speed - XFER_MW_DMA_0;
const unsigned int needed_pio[3] = {
XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
};
int pio = needed_pio[mwdma] - XFER_PIO_0;

- control = 3; /* IORDY|TIME1 */
-
- /* 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 */
-
- if (adev->devno) { /* Slave */
- master_data &= 0xFF4F; /* Mask out IORDY|TIME1|DMAONLY */
- master_data |= control << 4;
- pci_read_config_byte(dev, 0x44, &slave_data);
- slave_data &= ap->port_no ? 0x0F : 0xF0;
- /* Load the matching timing */
- slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << (ap->port_no ? 4 : 0);
- pci_write_config_byte(dev, 0x44, slave_data);
- } else { /* Master */
- master_data &= 0xCCF4; /* Mask out IORDY|TIME1|DMAONLY
- and master timing bits */
- master_data |= control;
- master_data |=
- (timings[pio][0] << 12) |
- (timings[pio][1] << 8);
- }
- udma_enable &= ~(1 << devid);
- pci_write_config_word(dev, master_port, master_data);
+ efar_set_timings(ap, adev, pio, 1);
}
- pci_write_config_byte(dev, 0x48, udma_enable);
- spin_unlock_irqrestore(&efar_lock, flags);
}

static struct scsi_host_template efar_sht = {
--
1.7.1


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