Merge tag 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev

Pull libata update from Jeff Garzik:
 "Changes, all of them boring and minor:

  1) Ugly MSFT Hyper-V workaround in ata_piix

  2) Fix a longstanding error recovery delay caused by excessive
     re-re-retries, when media errors occur.

  3) Minor hw-specific workarounds and quirks

  4) New PATA driver for ep93xx"

* tag 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  PATA host controller driver for ep93xx
  [libata] Add " 2GB ATA Flash Disk"/"ADMA428M" to DMA blacklist
  ata_generic: Skip is_intel_ider() check when ata_generic=1 is set
  libata-eh don't waste time retrying media errors (v3)
  ata_piix: defer disks to the Hyper-V drivers by default
  libata: add a host flag to ignore detected ATA devices

8 files changed, 1120 insertions, 4 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 6bdedd7cca2..2be8ef1d309 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -416,6 +416,15 @@ config PATA_EFAR
 
 	  If unsure, say N.
 
+config PATA_EP93XX
+	tristate "Cirrus Logic EP93xx PATA support"
+	depends on ARCH_EP93XX
+	help
+	  This option enables support for the PATA controller in
+	  the Cirrus Logic EP9312 and EP9315 ARM CPU.
+
+	  If unsure, say N.
+
 config PATA_HPT366
 	tristate "HPT 366/368 PATA support"
 	depends on PCI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 6ece5b7231a..a454a139b1d 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_PATA_CS5535)	+= pata_cs5535.o
 obj-$(CONFIG_PATA_CS5536)	+= pata_cs5536.o
 obj-$(CONFIG_PATA_CYPRESS)	+= pata_cypress.o
 obj-$(CONFIG_PATA_EFAR)		+= pata_efar.o
+obj-$(CONFIG_PATA_EP93XX)	+= pata_ep93xx.o
 obj-$(CONFIG_PATA_HPT366)	+= pata_hpt366.o
 obj-$(CONFIG_PATA_HPT37X)	+= pata_hpt37x.o
 obj-$(CONFIG_PATA_HPT3X2N)	+= pata_hpt3x2n.o
diff --git a/drivers/ata/ata_generic.c b/drivers/ata/ata_generic.c
index 7df56ec3181..aae115600b7 100644
--- a/drivers/ata/ata_generic.c
+++ b/drivers/ata/ata_generic.c
@@ -177,7 +177,7 @@ static int ata_generic_init_one(struct pci_dev *dev, const struct pci_device_id
 	if ((id->driver_data & ATA_GEN_CLASS_MATCH) && all_generic_ide == 0)
 		return -ENODEV;
 
-	if (id->driver_data & ATA_GEN_INTEL_IDER)
+	if ((id->driver_data & ATA_GEN_INTEL_IDER) && !all_generic_ide)
 		if (!is_intel_ider(dev))
 			return -ENODEV;
 
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index 7857e8fd0a3..3c809bfbccf 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1554,6 +1554,39 @@ static bool piix_broken_system_poweroff(struct pci_dev *pdev)
 	return false;
 }
 
+static int prefer_ms_hyperv = 1;
+module_param(prefer_ms_hyperv, int, 0);
+
+static void piix_ignore_devices_quirk(struct ata_host *host)
+{
+#if IS_ENABLED(CONFIG_HYPERV_STORAGE)
+	static const struct dmi_system_id ignore_hyperv[] = {
+		{
+			/* On Hyper-V hypervisors the disks are exposed on
+			 * both the emulated SATA controller and on the
+			 * paravirtualised drivers.  The CD/DVD devices
+			 * are only exposed on the emulated controller.
+			 * Request we ignore ATA devices on this host.
+			 */
+			.ident = "Hyper-V Virtual Machine",
+			.matches = {
+				DMI_MATCH(DMI_SYS_VENDOR,
+						"Microsoft Corporation"),
+				DMI_MATCH(DMI_PRODUCT_NAME, "Virtual Machine"),
+			},
+		},
+		{ }	/* terminate list */
+	};
+	const struct dmi_system_id *dmi = dmi_first_match(ignore_hyperv);
+
+	if (dmi && prefer_ms_hyperv) {
+		host->flags |= ATA_HOST_IGNORE_ATA;
+		dev_info(host->dev, "%s detected, ATA device ignore set\n",
+			dmi->ident);
+	}
+#endif
+}
+
 /**
  *	piix_init_one - Register PIIX ATA PCI device with kernel services
  *	@pdev: PCI device to register
@@ -1669,6 +1702,9 @@ static int __devinit piix_init_one(struct pci_dev *pdev,
 	}
 	host->flags |= ATA_HOST_PARALLEL_SCAN;
 
+	/* Allow hosts to specify device types to ignore when scanning. */
+	piix_ignore_devices_quirk(host);
+
 	pci_set_master(pdev);
 	return ata_pci_sff_activate_host(host, ata_bmdma_interrupt, sht);
 }
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 23763a1ec57..cece3a4d11e 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1973,6 +1973,12 @@ retry:
 	if (class == ATA_DEV_ATA) {
 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
 			goto err_out;
+		if (ap->host->flags & ATA_HOST_IGNORE_ATA &&
+							ata_id_is_ata(id)) {
+			ata_dev_dbg(dev,
+				"host indicates ignore ATA devices, ignored\n");
+			return -ENOENT;
+		}
 	} else {
 		if (ata_id_is_ata(id))
 			goto err_out;
@@ -4051,6 +4057,7 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
 	{ "SAMSUNG CD-ROM SN-124", "N001",	ATA_HORKAGE_NODMA },
 	{ "Seagate STT20000A", NULL,		ATA_HORKAGE_NODMA },
+	{ "2GB ATA Flash Disk", "ADMA428M",	ATA_HORKAGE_NODMA },
 	/* Odd clown on sil3726/4726 PMPs */
 	{ "Config  Disk",	NULL,		ATA_HORKAGE_DISABLE },
 
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index d1fbd59ead1..6d53cf9b3b6 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2047,6 +2047,26 @@ static unsigned int ata_eh_speed_down(struct ata_device *dev,
 }
 
 /**
+ *	ata_eh_worth_retry - analyze error and decide whether to retry
+ *	@qc: qc to possibly retry
+ *
+ *	Look at the cause of the error and decide if a retry
+ * 	might be useful or not.  We don't want to retry media errors
+ *	because the drive itself has probably already taken 10-30 seconds
+ *	doing its own internal retries before reporting the failure.
+ */
+static inline int ata_eh_worth_retry(struct ata_queued_cmd *qc)
+{
+	if (qc->flags & AC_ERR_MEDIA)
+		return 0;	/* don't retry media errors */
+	if (qc->flags & ATA_QCFLAG_IO)
+		return 1;	/* otherwise retry anything from fs stack */
+	if (qc->err_mask & AC_ERR_INVALID)
+		return 0;	/* don't retry these */
+	return qc->err_mask != AC_ERR_DEV;  /* retry if not dev error */
+}
+
+/**
  *	ata_eh_link_autopsy - analyze error and determine recovery action
  *	@link: host link to perform autopsy on
  *
@@ -2120,9 +2140,7 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
 
 		/* determine whether the command is worth retrying */
-		if (qc->flags & ATA_QCFLAG_IO ||
-		    (!(qc->err_mask & AC_ERR_INVALID) &&
-		     qc->err_mask != AC_ERR_DEV))
+		if (ata_eh_worth_retry(qc))
 			qc->flags |= ATA_QCFLAG_RETRY;
 
 		/* accumulate error info */
diff --git a/drivers/ata/pata_ep93xx.c b/drivers/ata/pata_ep93xx.c
new file mode 100644
index 00000000000..6ef2e3741f7
--- /dev/null
+++ b/drivers/ata/pata_ep93xx.c
@@ -0,0 +1,1044 @@
+/*
+ * EP93XX PATA controller driver.
+ *
+ * Copyright (c) 2012, Metasoft s.c.
+ *	Rafal Prylowski <prylowski@metasoft.pl>
+ *
+ * Based on pata_scc.c, pata_icside.c and on earlier version of EP93XX
+ * PATA driver by Lennert Buytenhek and Alessandro Zummo.
+ * Read/Write timings, resource management and other improvements
+ * from driver by Joao Ramos and Bartlomiej Zolnierkiewicz.
+ * DMA engine support based on spi-ep93xx.c by Mika Westerberg.
+ *
+ * Original copyrights:
+ *
+ * Support for Cirrus Logic's EP93xx (EP9312, EP9315) CPUs
+ * PATA host controller driver.
+ *
+ * Copyright (c) 2009, Bartlomiej Zolnierkiewicz
+ *
+ * Heavily based on the ep93xx-ide.c driver:
+ *
+ * Copyright (c) 2009, Joao Ramos <joao.ramos@inov.pt>
+ *		      INESC Inovacao (INOV)
+ *
+ * EP93XX PATA controller driver.
+ * Copyright (C) 2007 Lennert Buytenhek <buytenh@wantstofly.org>
+ *
+ * An ATA driver for the Cirrus Logic EP93xx PATA controller.
+ *
+ * Based on an earlier version by Alessandro Zummo, which is:
+ *   Copyright (C) 2006 Tower Technologies
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <scsi/scsi_host.h>
+#include <linux/ata.h>
+#include <linux/libata.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/ktime.h>
+
+#include <mach/dma.h>
+#include <mach/platform.h>
+
+#define DRV_NAME	"ep93xx-ide"
+#define DRV_VERSION	"1.0"
+
+enum {
+	/* IDE Control Register */
+	IDECTRL				= 0x00,
+	IDECTRL_CS0N			= (1 << 0),
+	IDECTRL_CS1N			= (1 << 1),
+	IDECTRL_DIORN			= (1 << 5),
+	IDECTRL_DIOWN			= (1 << 6),
+	IDECTRL_INTRQ			= (1 << 9),
+	IDECTRL_IORDY			= (1 << 10),
+	/*
+	 * the device IDE register to be accessed is selected through
+	 * IDECTRL register's specific bitfields 'DA', 'CS1N' and 'CS0N':
+	 *   b4   b3   b2    b1     b0
+	 *   A2   A1   A0   CS1N   CS0N
+	 * the values filled in this structure allows the value to be directly
+	 * ORed to the IDECTRL register, hence giving directly the A[2:0] and
+	 * CS1N/CS0N values for each IDE register.
+	 * The values correspond to the transformation:
+	 *   ((real IDE address) << 2) | CS1N value << 1 | CS0N value
+	 */
+	IDECTRL_ADDR_CMD		= 0 + 2, /* CS1 */
+	IDECTRL_ADDR_DATA		= (ATA_REG_DATA << 2) + 2,
+	IDECTRL_ADDR_ERROR		= (ATA_REG_ERR << 2) + 2,
+	IDECTRL_ADDR_FEATURE		= (ATA_REG_FEATURE << 2) + 2,
+	IDECTRL_ADDR_NSECT		= (ATA_REG_NSECT << 2) + 2,
+	IDECTRL_ADDR_LBAL		= (ATA_REG_LBAL << 2) + 2,
+	IDECTRL_ADDR_LBAM		= (ATA_REG_LBAM << 2) + 2,
+	IDECTRL_ADDR_LBAH		= (ATA_REG_LBAH << 2) + 2,
+	IDECTRL_ADDR_DEVICE		= (ATA_REG_DEVICE << 2) + 2,
+	IDECTRL_ADDR_STATUS		= (ATA_REG_STATUS << 2) + 2,
+	IDECTRL_ADDR_COMMAND		= (ATA_REG_CMD << 2) + 2,
+	IDECTRL_ADDR_ALTSTATUS		= (0x06 << 2) + 1, /* CS0 */
+	IDECTRL_ADDR_CTL		= (0x06 << 2) + 1, /* CS0 */
+
+	/* IDE Configuration Register */
+	IDECFG				= 0x04,
+	IDECFG_IDEEN			= (1 << 0),
+	IDECFG_PIO			= (1 << 1),
+	IDECFG_MDMA			= (1 << 2),
+	IDECFG_UDMA			= (1 << 3),
+	IDECFG_MODE_SHIFT		= 4,
+	IDECFG_MODE_MASK		= (0xf << 4),
+	IDECFG_WST_SHIFT		= 8,
+	IDECFG_WST_MASK			= (0x3 << 8),
+
+	/* MDMA Operation Register */
+	IDEMDMAOP			= 0x08,
+
+	/* UDMA Operation Register */
+	IDEUDMAOP			= 0x0c,
+	IDEUDMAOP_UEN			= (1 << 0),
+	IDEUDMAOP_RWOP			= (1 << 1),
+
+	/* PIO/MDMA/UDMA Data Registers */
+	IDEDATAOUT			= 0x10,
+	IDEDATAIN			= 0x14,
+	IDEMDMADATAOUT			= 0x18,
+	IDEMDMADATAIN			= 0x1c,
+	IDEUDMADATAOUT			= 0x20,
+	IDEUDMADATAIN			= 0x24,
+
+	/* UDMA Status Register */
+	IDEUDMASTS			= 0x28,
+	IDEUDMASTS_DMAIDE		= (1 << 16),
+	IDEUDMASTS_INTIDE		= (1 << 17),
+	IDEUDMASTS_SBUSY		= (1 << 18),
+	IDEUDMASTS_NDO			= (1 << 24),
+	IDEUDMASTS_NDI			= (1 << 25),
+	IDEUDMASTS_N4X			= (1 << 26),
+
+	/* UDMA Debug Status Register */
+	IDEUDMADEBUG			= 0x2c,
+};
+
+struct ep93xx_pata_data {
+	const struct platform_device *pdev;
+	void __iomem *ide_base;
+	struct ata_timing t;
+	bool iordy;
+
+	unsigned long udma_in_phys;
+	unsigned long udma_out_phys;
+
+	struct dma_chan *dma_rx_channel;
+	struct ep93xx_dma_data dma_rx_data;
+	struct dma_chan *dma_tx_channel;
+	struct ep93xx_dma_data dma_tx_data;
+};
+
+static void ep93xx_pata_clear_regs(void __iomem *base)
+{
+	writel(IDECTRL_CS0N | IDECTRL_CS1N | IDECTRL_DIORN |
+		IDECTRL_DIOWN, base + IDECTRL);
+
+	writel(0, base + IDECFG);
+	writel(0, base + IDEMDMAOP);
+	writel(0, base + IDEUDMAOP);
+	writel(0, base + IDEDATAOUT);
+	writel(0, base + IDEDATAIN);
+	writel(0, base + IDEMDMADATAOUT);
+	writel(0, base + IDEMDMADATAIN);
+	writel(0, base + IDEUDMADATAOUT);
+	writel(0, base + IDEUDMADATAIN);
+	writel(0, base + IDEUDMADEBUG);
+}
+
+static bool ep93xx_pata_check_iordy(void __iomem *base)
+{
+	return !!(readl(base + IDECTRL) & IDECTRL_IORDY);
+}
+
+/*
+ * According to EP93xx User's Guide, WST field of IDECFG specifies number
+ * of HCLK cycles to hold the data bus after a PIO write operation.
+ * It should be programmed to guarantee following delays:
+ *
+ * PIO Mode   [ns]
+ * 0          30
+ * 1          20
+ * 2          15
+ * 3          10
+ * 4          5
+ *
+ * Maximum possible value for HCLK is 100MHz.
+ */
+static int ep93xx_pata_get_wst(int pio_mode)
+{
+	int val;
+
+	if (pio_mode == 0)
+		val = 3;
+	else if (pio_mode < 3)
+		val = 2;
+	else
+		val = 1;
+
+	return val << IDECFG_WST_SHIFT;
+}
+
+static void ep93xx_pata_enable_pio(void __iomem *base, int pio_mode)
+{
+	writel(IDECFG_IDEEN | IDECFG_PIO |
+		ep93xx_pata_get_wst(pio_mode) |
+		(pio_mode << IDECFG_MODE_SHIFT), base + IDECFG);
+}
+
+/*
+ * Based on delay loop found in mach-pxa/mp900.c.
+ *
+ * Single iteration should take 5 cpu cycles. This is 25ns assuming the
+ * fastest ep93xx cpu speed (200MHz) and is better optimized for PIO4 timings
+ * than eg. 20ns.
+ */
+static void ep93xx_pata_delay(unsigned long count)
+{
+	__asm__ volatile (
+		"0:\n"
+		"mov r0, r0\n"
+		"subs %0, %1, #1\n"
+		"bge 0b\n"
+		: "=r" (count)
+		: "0" (count)
+	);
+}
+
+static unsigned long ep93xx_pata_wait_for_iordy(void __iomem *base,
+						unsigned long t2)
+{
+	/*
+	 * According to ATA specification, IORDY pin can be first sampled
+	 * tA = 35ns after activation of DIOR-/DIOW-. Maximum IORDY pulse
+	 * width is tB = 1250ns.
+	 *
+	 * We are already t2 delay loop iterations after activation of
+	 * DIOR-/DIOW-, so we set timeout to (1250 + 35) / 25 - t2 additional
+	 * delay loop iterations.
+	 */
+	unsigned long start = (1250 + 35) / 25 - t2;
+	unsigned long counter = start;
+
+	while (!ep93xx_pata_check_iordy(base) && counter--)
+		ep93xx_pata_delay(1);
+	return start - counter;
+}
+
+/* common part at start of ep93xx_pata_read/write() */
+static void ep93xx_pata_rw_begin(void __iomem *base, unsigned long addr,
+				 unsigned long t1)
+{
+	writel(IDECTRL_DIOWN | IDECTRL_DIORN | addr, base + IDECTRL);
+	ep93xx_pata_delay(t1);
+}
+
+/* common part at end of ep93xx_pata_read/write() */
+static void ep93xx_pata_rw_end(void __iomem *base, unsigned long addr,
+			       bool iordy, unsigned long t0, unsigned long t2,
+			       unsigned long t2i)
+{
+	ep93xx_pata_delay(t2);
+	/* lengthen t2 if needed */
+	if (iordy)
+		t2 += ep93xx_pata_wait_for_iordy(base, t2);
+	writel(IDECTRL_DIOWN | IDECTRL_DIORN | addr, base + IDECTRL);
+	if (t0 > t2 && t0 - t2 > t2i)
+		ep93xx_pata_delay(t0 - t2);
+	else
+		ep93xx_pata_delay(t2i);
+}
+
+static u16 ep93xx_pata_read(struct ep93xx_pata_data *drv_data,
+			    unsigned long addr,
+			    bool reg)
+{
+	void __iomem *base = drv_data->ide_base;
+	const struct ata_timing *t = &drv_data->t;
+	unsigned long t0 = reg ? t->cyc8b : t->cycle;
+	unsigned long t2 = reg ? t->act8b : t->active;
+	unsigned long t2i = reg ? t->rec8b : t->recover;
+
+	ep93xx_pata_rw_begin(base, addr, t->setup);
+	writel(IDECTRL_DIOWN | addr, base + IDECTRL);
+	/*
+	 * The IDEDATAIN register is loaded from the DD pins at the positive
+	 * edge of the DIORN signal. (EP93xx UG p27-14)
+	 */
+	ep93xx_pata_rw_end(base, addr, drv_data->iordy, t0, t2, t2i);
+	return readl(base + IDEDATAIN);
+}
+
+/* IDE register read */
+static u16 ep93xx_pata_read_reg(struct ep93xx_pata_data *drv_data,
+				unsigned long addr)
+{
+	return ep93xx_pata_read(drv_data, addr, true);
+}
+
+/* PIO data read */
+static u16 ep93xx_pata_read_data(struct ep93xx_pata_data *drv_data,
+				 unsigned long addr)
+{
+	return ep93xx_pata_read(drv_data, addr, false);
+}
+
+static void ep93xx_pata_write(struct ep93xx_pata_data *drv_data,
+			      u16 value, unsigned long addr,
+			      bool reg)
+{
+	void __iomem *base = drv_data->ide_base;
+	const struct ata_timing *t = &drv_data->t;
+	unsigned long t0 = reg ? t->cyc8b : t->cycle;
+	unsigned long t2 = reg ? t->act8b : t->active;
+	unsigned long t2i = reg ? t->rec8b : t->recover;
+
+	ep93xx_pata_rw_begin(base, addr, t->setup);
+	/*
+	 * Value from IDEDATAOUT register is driven onto the DD pins when
+	 * DIOWN is low. (EP93xx UG p27-13)
+	 */
+	writel(value, base + IDEDATAOUT);
+	writel(IDECTRL_DIORN | addr, base + IDECTRL);
+	ep93xx_pata_rw_end(base, addr, drv_data->iordy, t0, t2, t2i);
+}
+
+/* IDE register write */
+static void ep93xx_pata_write_reg(struct ep93xx_pata_data *drv_data,
+				  u16 value, unsigned long addr)
+{
+	ep93xx_pata_write(drv_data, value, addr, true);
+}
+
+/* PIO data write */
+static void ep93xx_pata_write_data(struct ep93xx_pata_data *drv_data,
+				   u16 value, unsigned long addr)
+{
+	ep93xx_pata_write(drv_data, value, addr, false);
+}
+
+static void ep93xx_pata_set_piomode(struct ata_port *ap,
+				    struct ata_device *adev)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	struct ata_device *pair = ata_dev_pair(adev);
+	/*
+	 * Calculate timings for the delay loop, assuming ep93xx cpu speed
+	 * is 200MHz (maximum possible for ep93xx). If actual cpu speed is
+	 * slower, we will wait a bit longer in each delay.
+	 * Additional division of cpu speed by 5, because single iteration
+	 * of our delay loop takes 5 cpu cycles (25ns).
+	 */
+	unsigned long T = 1000000 / (200 / 5);
+
+	ata_timing_compute(adev, adev->pio_mode, &drv_data->t, T, 0);
+	if (pair && pair->pio_mode) {
+		struct ata_timing t;
+		ata_timing_compute(pair, pair->pio_mode, &t, T, 0);
+		ata_timing_merge(&t, &drv_data->t, &drv_data->t,
+			ATA_TIMING_SETUP | ATA_TIMING_8BIT);
+	}
+	drv_data->iordy = ata_pio_need_iordy(adev);
+
+	ep93xx_pata_enable_pio(drv_data->ide_base,
+			       adev->pio_mode - XFER_PIO_0);
+}
+
+/* Note: original code is ata_sff_check_status */
+static u8 ep93xx_pata_check_status(struct ata_port *ap)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+
+	return ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_STATUS);
+}
+
+static u8 ep93xx_pata_check_altstatus(struct ata_port *ap)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+
+	return ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_ALTSTATUS);
+}
+
+/* Note: original code is ata_sff_tf_load */
+static void ep93xx_pata_tf_load(struct ata_port *ap,
+				const struct ata_taskfile *tf)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
+
+	if (tf->ctl != ap->last_ctl) {
+		ep93xx_pata_write_reg(drv_data, tf->ctl, IDECTRL_ADDR_CTL);
+		ap->last_ctl = tf->ctl;
+		ata_wait_idle(ap);
+	}
+
+	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
+		ep93xx_pata_write_reg(drv_data, tf->hob_feature,
+			IDECTRL_ADDR_FEATURE);
+		ep93xx_pata_write_reg(drv_data, tf->hob_nsect,
+			IDECTRL_ADDR_NSECT);
+		ep93xx_pata_write_reg(drv_data, tf->hob_lbal,
+			IDECTRL_ADDR_LBAL);
+		ep93xx_pata_write_reg(drv_data, tf->hob_lbam,
+			IDECTRL_ADDR_LBAM);
+		ep93xx_pata_write_reg(drv_data, tf->hob_lbah,
+			IDECTRL_ADDR_LBAH);
+	}
+
+	if (is_addr) {
+		ep93xx_pata_write_reg(drv_data, tf->feature,
+			IDECTRL_ADDR_FEATURE);
+		ep93xx_pata_write_reg(drv_data, tf->nsect, IDECTRL_ADDR_NSECT);
+		ep93xx_pata_write_reg(drv_data, tf->lbal, IDECTRL_ADDR_LBAL);
+		ep93xx_pata_write_reg(drv_data, tf->lbam, IDECTRL_ADDR_LBAM);
+		ep93xx_pata_write_reg(drv_data, tf->lbah, IDECTRL_ADDR_LBAH);
+	}
+
+	if (tf->flags & ATA_TFLAG_DEVICE)
+		ep93xx_pata_write_reg(drv_data, tf->device,
+			IDECTRL_ADDR_DEVICE);
+
+	ata_wait_idle(ap);
+}
+
+/* Note: original code is ata_sff_tf_read */
+static void ep93xx_pata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+
+	tf->command = ep93xx_pata_check_status(ap);
+	tf->feature = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_FEATURE);
+	tf->nsect = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_NSECT);
+	tf->lbal = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAL);
+	tf->lbam = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAM);
+	tf->lbah = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAH);
+	tf->device = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_DEVICE);
+
+	if (tf->flags & ATA_TFLAG_LBA48) {
+		ep93xx_pata_write_reg(drv_data, tf->ctl | ATA_HOB,
+			IDECTRL_ADDR_CTL);
+		tf->hob_feature = ep93xx_pata_read_reg(drv_data,
+			IDECTRL_ADDR_FEATURE);
+		tf->hob_nsect = ep93xx_pata_read_reg(drv_data,
+			IDECTRL_ADDR_NSECT);
+		tf->hob_lbal = ep93xx_pata_read_reg(drv_data,
+			IDECTRL_ADDR_LBAL);
+		tf->hob_lbam = ep93xx_pata_read_reg(drv_data,
+			IDECTRL_ADDR_LBAM);
+		tf->hob_lbah = ep93xx_pata_read_reg(drv_data,
+			IDECTRL_ADDR_LBAH);
+		ep93xx_pata_write_reg(drv_data, tf->ctl, IDECTRL_ADDR_CTL);
+		ap->last_ctl = tf->ctl;
+	}
+}
+
+/* Note: original code is ata_sff_exec_command */
+static void ep93xx_pata_exec_command(struct ata_port *ap,
+				     const struct ata_taskfile *tf)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+
+	ep93xx_pata_write_reg(drv_data, tf->command,
+			  IDECTRL_ADDR_COMMAND);
+	ata_sff_pause(ap);
+}
+
+/* Note: original code is ata_sff_dev_select */
+static void ep93xx_pata_dev_select(struct ata_port *ap, unsigned int device)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	u8 tmp = ATA_DEVICE_OBS;
+
+	if (device != 0)
+		tmp |= ATA_DEV1;
+
+	ep93xx_pata_write_reg(drv_data, tmp, IDECTRL_ADDR_DEVICE);
+	ata_sff_pause(ap);	/* needed; also flushes, for mmio */
+}
+
+/* Note: original code is ata_sff_set_devctl */
+static void ep93xx_pata_set_devctl(struct ata_port *ap, u8 ctl)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+
+	ep93xx_pata_write_reg(drv_data, ctl, IDECTRL_ADDR_CTL);
+}
+
+/* Note: original code is ata_sff_data_xfer */
+static unsigned int ep93xx_pata_data_xfer(struct ata_device *adev,
+					  unsigned char *buf,
+					  unsigned int buflen, int rw)
+{
+	struct ata_port *ap = adev->link->ap;
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	u16 *data = (u16 *)buf;
+	unsigned int words = buflen >> 1;
+
+	/* Transfer multiple of 2 bytes */
+	while (words--)
+		if (rw == READ)
+			*data++ = cpu_to_le16(
+				ep93xx_pata_read_data(
+					drv_data, IDECTRL_ADDR_DATA));
+		else
+			ep93xx_pata_write_data(drv_data, le16_to_cpu(*data++),
+				IDECTRL_ADDR_DATA);
+
+	/* Transfer trailing 1 byte, if any. */
+	if (unlikely(buflen & 0x01)) {
+		unsigned char pad[2] = { };
+
+		buf += buflen - 1;
+
+		if (rw == READ) {
+			*pad = cpu_to_le16(
+				ep93xx_pata_read_data(
+					drv_data, IDECTRL_ADDR_DATA));
+			*buf = pad[0];
+		} else {
+			pad[0] = *buf;
+			ep93xx_pata_write_data(drv_data, le16_to_cpu(*pad),
+					  IDECTRL_ADDR_DATA);
+		}
+		words++;
+	}
+
+	return words << 1;
+}
+
+/* Note: original code is ata_devchk */
+static bool ep93xx_pata_device_is_present(struct ata_port *ap,
+					  unsigned int device)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	u8 nsect, lbal;
+
+	ap->ops->sff_dev_select(ap, device);
+
+	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_NSECT);
+	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_LBAL);
+
+	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_NSECT);
+	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_LBAL);
+
+	ep93xx_pata_write_reg(drv_data, 0x55, IDECTRL_ADDR_NSECT);
+	ep93xx_pata_write_reg(drv_data, 0xaa, IDECTRL_ADDR_LBAL);
+
+	nsect = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_NSECT);
+	lbal = ep93xx_pata_read_reg(drv_data, IDECTRL_ADDR_LBAL);
+
+	if ((nsect == 0x55) && (lbal == 0xaa))
+		return true;
+
+	return false;
+}
+
+/* Note: original code is ata_sff_wait_after_reset */
+static int ep93xx_pata_wait_after_reset(struct ata_link *link,
+					unsigned int devmask,
+					unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	unsigned int dev0 = devmask & (1 << 0);
+	unsigned int dev1 = devmask & (1 << 1);
+	int rc, ret = 0;
+
+	ata_msleep(ap, ATA_WAIT_AFTER_RESET);
+
+	/* always check readiness of the master device */
+	rc = ata_sff_wait_ready(link, deadline);
+	/*
+	 * -ENODEV means the odd clown forgot the D7 pulldown resistor
+	 * and TF status is 0xff, bail out on it too.
+	 */
+	if (rc)
+		return rc;
+
+	/*
+	 * if device 1 was found in ata_devchk, wait for register
+	 * access briefly, then wait for BSY to clear.
+	 */
+	if (dev1) {
+		int i;
+
+		ap->ops->sff_dev_select(ap, 1);
+
+		/*
+		 * Wait for register access.  Some ATAPI devices fail
+		 * to set nsect/lbal after reset, so don't waste too
+		 * much time on it.  We're gonna wait for !BSY anyway.
+		 */
+		for (i = 0; i < 2; i++) {
+			u8 nsect, lbal;
+
+			nsect = ep93xx_pata_read_reg(drv_data,
+				IDECTRL_ADDR_NSECT);
+			lbal = ep93xx_pata_read_reg(drv_data,
+				IDECTRL_ADDR_LBAL);
+			if (nsect == 1 && lbal == 1)
+				break;
+			msleep(50);	/* give drive a breather */
+		}
+
+		rc = ata_sff_wait_ready(link, deadline);
+		if (rc) {
+			if (rc != -ENODEV)
+				return rc;
+			ret = rc;
+		}
+	}
+	/* is all this really necessary? */
+	ap->ops->sff_dev_select(ap, 0);
+	if (dev1)
+		ap->ops->sff_dev_select(ap, 1);
+	if (dev0)
+		ap->ops->sff_dev_select(ap, 0);
+
+	return ret;
+}
+
+/* Note: original code is ata_bus_softreset */
+static int ep93xx_pata_bus_softreset(struct ata_port *ap, unsigned int devmask,
+				     unsigned long deadline)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+
+	ep93xx_pata_write_reg(drv_data, ap->ctl, IDECTRL_ADDR_CTL);
+	udelay(20);		/* FIXME: flush */
+	ep93xx_pata_write_reg(drv_data, ap->ctl | ATA_SRST, IDECTRL_ADDR_CTL);
+	udelay(20);		/* FIXME: flush */
+	ep93xx_pata_write_reg(drv_data, ap->ctl, IDECTRL_ADDR_CTL);
+	ap->last_ctl = ap->ctl;
+
+	return ep93xx_pata_wait_after_reset(&ap->link, devmask, deadline);
+}
+
+static void ep93xx_pata_release_dma(struct ep93xx_pata_data *drv_data)
+{
+	if (drv_data->dma_rx_channel) {
+		dma_release_channel(drv_data->dma_rx_channel);
+		drv_data->dma_rx_channel = NULL;
+	}
+	if (drv_data->dma_tx_channel) {
+		dma_release_channel(drv_data->dma_tx_channel);
+		drv_data->dma_tx_channel = NULL;
+	}
+}
+
+static bool ep93xx_pata_dma_filter(struct dma_chan *chan, void *filter_param)
+{
+	if (ep93xx_dma_chan_is_m2p(chan))
+		return false;
+
+	chan->private = filter_param;
+	return true;
+}
+
+static void ep93xx_pata_dma_init(struct ep93xx_pata_data *drv_data)
+{
+	const struct platform_device *pdev = drv_data->pdev;
+	dma_cap_mask_t mask;
+	struct dma_slave_config conf;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	/*
+	 * Request two channels for IDE. Another possibility would be
+	 * to request only one channel, and reprogram it's direction at
+	 * start of new transfer.
+	 */
+	drv_data->dma_rx_data.port = EP93XX_DMA_IDE;
+	drv_data->dma_rx_data.direction = DMA_FROM_DEVICE;
+	drv_data->dma_rx_data.name = "ep93xx-pata-rx";
+	drv_data->dma_rx_channel = dma_request_channel(mask,
+		ep93xx_pata_dma_filter, &drv_data->dma_rx_data);
+	if (!drv_data->dma_rx_channel)
+		return;
+
+	drv_data->dma_tx_data.port = EP93XX_DMA_IDE;
+	drv_data->dma_tx_data.direction = DMA_TO_DEVICE;
+	drv_data->dma_tx_data.name = "ep93xx-pata-tx";
+	drv_data->dma_tx_channel = dma_request_channel(mask,
+		ep93xx_pata_dma_filter, &drv_data->dma_tx_data);
+	if (!drv_data->dma_tx_channel) {
+		dma_release_channel(drv_data->dma_rx_channel);
+		return;
+	}
+
+	/* Configure receive channel direction and source address */
+	memset(&conf, 0, sizeof(conf));
+	conf.direction = DMA_FROM_DEVICE;
+	conf.src_addr = drv_data->udma_in_phys;
+	conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	if (dmaengine_slave_config(drv_data->dma_rx_channel, &conf)) {
+		dev_err(&pdev->dev, "failed to configure rx dma channel\n");
+		ep93xx_pata_release_dma(drv_data);
+		return;
+	}
+
+	/* Configure transmit channel direction and destination address */
+	memset(&conf, 0, sizeof(conf));
+	conf.direction = DMA_TO_DEVICE;
+	conf.dst_addr = drv_data->udma_out_phys;
+	conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	if (dmaengine_slave_config(drv_data->dma_tx_channel, &conf)) {
+		dev_err(&pdev->dev, "failed to configure tx dma channel\n");
+		ep93xx_pata_release_dma(drv_data);
+	}
+}
+
+static void ep93xx_pata_dma_start(struct ata_queued_cmd *qc)
+{
+	struct dma_async_tx_descriptor *txd;
+	struct ep93xx_pata_data *drv_data = qc->ap->host->private_data;
+	void __iomem *base = drv_data->ide_base;
+	struct ata_device *adev = qc->dev;
+	u32 v = qc->dma_dir == DMA_TO_DEVICE ? IDEUDMAOP_RWOP : 0;
+	struct dma_chan *channel = qc->dma_dir == DMA_TO_DEVICE
+		? drv_data->dma_tx_channel : drv_data->dma_rx_channel;
+
+	txd = channel->device->device_prep_slave_sg(channel, qc->sg,
+		 qc->n_elem, qc->dma_dir, DMA_CTRL_ACK, NULL);
+	if (!txd) {
+		dev_err(qc->ap->dev, "failed to prepare slave for sg dma\n");
+		return;
+	}
+	txd->callback = NULL;
+	txd->callback_param = NULL;
+
+	if (dmaengine_submit(txd) < 0) {
+		dev_err(qc->ap->dev, "failed to submit dma transfer\n");
+		return;
+	}
+	dma_async_issue_pending(channel);
+
+	/*
+	 * When enabling UDMA operation, IDEUDMAOP register needs to be
+	 * programmed in three step sequence:
+	 * 1) set or clear the RWOP bit,
+	 * 2) perform dummy read of the register,
+	 * 3) set the UEN bit.
+	 */
+	writel(v, base + IDEUDMAOP);
+	readl(base + IDEUDMAOP);
+	writel(v | IDEUDMAOP_UEN, base + IDEUDMAOP);
+
+	writel(IDECFG_IDEEN | IDECFG_UDMA |
+		((adev->xfer_mode - XFER_UDMA_0) << IDECFG_MODE_SHIFT),
+		base + IDECFG);
+}
+
+static void ep93xx_pata_dma_stop(struct ata_queued_cmd *qc)
+{
+	struct ep93xx_pata_data *drv_data = qc->ap->host->private_data;
+	void __iomem *base = drv_data->ide_base;
+
+	/* terminate all dma transfers, if not yet finished */
+	dmaengine_terminate_all(drv_data->dma_rx_channel);
+	dmaengine_terminate_all(drv_data->dma_tx_channel);
+
+	/*
+	 * To properly stop IDE-DMA, IDEUDMAOP register must to be cleared
+	 * and IDECTRL register must be set to default value.
+	 */
+	writel(0, base + IDEUDMAOP);
+	writel(readl(base + IDECTRL) | IDECTRL_DIOWN | IDECTRL_DIORN |
+		IDECTRL_CS0N | IDECTRL_CS1N, base + IDECTRL);
+
+	ep93xx_pata_enable_pio(drv_data->ide_base,
+		qc->dev->pio_mode - XFER_PIO_0);
+
+	ata_sff_dma_pause(qc->ap);
+}
+
+static void ep93xx_pata_dma_setup(struct ata_queued_cmd *qc)
+{
+	qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
+}
+
+static u8 ep93xx_pata_dma_status(struct ata_port *ap)
+{
+	struct ep93xx_pata_data *drv_data = ap->host->private_data;
+	u32 val = readl(drv_data->ide_base + IDEUDMASTS);
+
+	/*
+	 * UDMA Status Register bits:
+	 *
+	 * DMAIDE - DMA request signal from UDMA state machine,
+	 * INTIDE - INT line generated by UDMA because of errors in the
+	 *          state machine,
+	 * SBUSY - UDMA state machine busy, not in idle state,
+	 * NDO   - error for data-out not completed,
+	 * NDI   - error for data-in not completed,
+	 * N4X   - error for data transferred not multiplies of four
+	 *         32-bit words.
+	 * (EP93xx UG p27-17)
+	 */
+	if (val & IDEUDMASTS_NDO || val & IDEUDMASTS_NDI ||
+	    val & IDEUDMASTS_N4X || val & IDEUDMASTS_INTIDE)
+		return ATA_DMA_ERR;
+
+	/* read INTRQ (INT[3]) pin input state */
+	if (readl(drv_data->ide_base + IDECTRL) & IDECTRL_INTRQ)
+		return ATA_DMA_INTR;
+
+	if (val & IDEUDMASTS_SBUSY || val & IDEUDMASTS_DMAIDE)
+		return ATA_DMA_ACTIVE;
+
+	return 0;
+}
+
+/* Note: original code is ata_sff_softreset */
+static int ep93xx_pata_softreset(struct ata_link *al, unsigned int *classes,
+				 unsigned long deadline)
+{
+	struct ata_port *ap = al->ap;
+	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
+	unsigned int devmask = 0;
+	int rc;
+	u8 err;
+
+	/* determine if device 0/1 are present */
+	if (ep93xx_pata_device_is_present(ap, 0))
+		devmask |= (1 << 0);
+	if (slave_possible && ep93xx_pata_device_is_present(ap, 1))
+		devmask |= (1 << 1);
+
+	/* select device 0 again */
+	ap->ops->sff_dev_select(al->ap, 0);
+
+	/* issue bus reset */
+	rc = ep93xx_pata_bus_softreset(ap, devmask, deadline);
+	/* if link is ocuppied, -ENODEV too is an error */
+	if (rc && (rc != -ENODEV || sata_scr_valid(al))) {
+		ata_link_printk(al, KERN_ERR, "SRST failed (errno=%d)\n",
+				rc);
+		return rc;
+	}
+
+	/* determine by signature whether we have ATA or ATAPI devices */
+	classes[0] = ata_sff_dev_classify(&al->device[0], devmask & (1 << 0),
+					  &err);
+	if (slave_possible && err != 0x81)
+		classes[1] = ata_sff_dev_classify(&al->device[1],
+						  devmask & (1 << 1), &err);
+
+	return 0;
+}
+
+/* Note: original code is ata_sff_drain_fifo */