Patchwork 460EX on-chip SATA driver<kernel 2.6.33> < resubmission : 02>

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Submitter Rupjyoti Sarmah
Date April 6, 2010, 11:41 a.m.
Message ID <201004061141.o36BfTsr028163@amcc.com>
Download mbox | patch
Permalink /patch/49496/
State Not Applicable
Delegated to: David Miller
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Comments

Rupjyoti Sarmah - April 6, 2010, 11:41 a.m.
This patch enables the on-chip DWC SATA controller of the AppliedMicro processor 460EX.

Signed-off-by: Rupjyoti Sarmah <rsarmah@appliedmicro.com> 
Signed-off-by: Mark Miesfeld <mmiesfeld@appliedmicro.com>
Signed-off-by: Prodyut Hazarika <phazarika@appliedmicro.com>
---
 arch/powerpc/boot/dts/canyonlands.dts |    8 +
 drivers/ata/Kconfig                   |    9 +
 drivers/ata/Makefile                  |    1 +
 drivers/ata/sata_dwc.c                | 1965 +++++++++++++++++++++++++++++++++
 4 files changed, 1983 insertions(+), 0 deletions(-)
 create mode 100644 drivers/ata/sata_dwc.c
Jeff Garzik - April 6, 2010, 3:16 p.m.
On 04/06/2010 07:41 AM, Rupjyoti Sarmah wrote:

General comment:  remove "inline" and let the compiler select those 
functions that need it.


> +struct sata_dwc_host_priv {
> +
> +	void __iomem *scr_addr_sstatus;
> +	u32 sata_dwc_sactive_issued;
> +	u32 sata_dwc_sactive_queued;
> +	u32 dma_interrupt_count;
> +	struct ahb_dma_regs *sata_dma_regs;
> +	struct device *dwc_dev;
> +
> +};

use proper indentation (separate type from member name with tabs)


> +struct sata_dwc_host_priv host_pvt;
> +
> +/*
> + * Prototypes
> + */
> +static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag);
> +static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
> +				u32 check_status);
> +static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
> +static void sata_dwc_port_stop(struct ata_port *ap);
> +static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);
> +
> +static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq);
> +static void dma_dwc_exit(struct sata_dwc_device *hsdev);
> +static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
> +			      struct lli *lli, dma_addr_t dma_lli,
> +			      void __iomem *addr, int dir);
> +static void dma_dwc_xfer_start(int dma_ch);
> +
> +static const char *dir_2_txt(enum dma_data_direction dir)
> +{
> +	switch (dir) {
> +	case DMA_BIDIRECTIONAL:
> +		return "bi";
> +	case DMA_FROM_DEVICE:
> +		return "from";
> +	case DMA_TO_DEVICE:
> +		return "to";
> +	case DMA_NONE:
> +		return "none";
> +	default:
> +		return "err";
> +	}
> +}
> +
> +static const char *prot_2_txt(enum ata_tf_protocols protocol)
> +{
> +	switch (protocol) {
> +	case ATA_PROT_UNKNOWN:
> +		return "unknown";
> +	case ATA_PROT_NODATA:
> +		return "nodata";
> +	case ATA_PROT_PIO:
> +		return "pio";
> +	case ATA_PROT_DMA:
> +		return "dma";
> +	case ATA_PROT_NCQ:
> +		return "ncq";
> +	case ATAPI_PROT_PIO:
> +		return "atapi pio";
> +	case ATAPI_PROT_NODATA:
> +		return "atapi nodata";
> +	case ATAPI_PROT_DMA:
> +		return "atapi dma";
> +	default:
> +		return "err";
> +	}
> +}
> +
> +inline const char *ata_cmd_2_txt(const struct ata_taskfile *tf)
> +{
> +	switch (tf->command) {
> +	case ATA_CMD_CHK_POWER:
> +		return "ATA_CMD_CHK_POWER";
> +	case ATA_CMD_EDD:
> +		return "ATA_CMD_EDD";
> +	case ATA_CMD_FLUSH:
> +		return "ATA_CMD_FLUSH";
> +	case ATA_CMD_FLUSH_EXT:
> +		return "ATA_CMD_FLUSH_EXT";
> +	case ATA_CMD_ID_ATA:
> +		return "ATA_CMD_ID_ATA";
> +	case ATA_CMD_ID_ATAPI:
> +		return "ATA_CMD_ID_ATAPI";
> +	case ATA_CMD_FPDMA_READ:
> +		return "ATA_CMD_FPDMA_READ";
> +	case ATA_CMD_FPDMA_WRITE:
> +		return "ATA_CMD_FPDMA_WRITE";
> +	case ATA_CMD_READ:
> +		return "ATA_CMD_READ";
> +	case ATA_CMD_READ_EXT:
> +		return "ATA_CMD_READ_EXT";
> +	case ATA_CMD_READ_NATIVE_MAX_EXT:
> +		return "ATA_CMD_READ_NATIVE_MAX_EXT";
> +	case ATA_CMD_VERIFY_EXT:
> +		return "ATA_CMD_VERIFY_EXT";
> +	case ATA_CMD_WRITE:
> +		return "ATA_CMD_WRITE";
> +	case ATA_CMD_WRITE_EXT:
> +		return "ATA_CMD_WRITE_EXT";
> +	case ATA_CMD_PIO_READ:
> +		return "ATA_CMD_PIO_READ";
> +	case ATA_CMD_PIO_READ_EXT:
> +		return "ATA_CMD_PIO_READ_EXT";
> +	case ATA_CMD_PIO_WRITE:
> +		return "ATA_CMD_PIO_WRITE";
> +	case ATA_CMD_PIO_WRITE_EXT:
> +		return "ATA_CMD_PIO_WRITE_EXT";
> +	case ATA_CMD_SET_FEATURES:
> +		return "ATA_CMD_SET_FEATURES";
> +	case ATA_CMD_PACKET:
> +		return "ATA_CMD_PACKET";
> +	default:
> +		return "ATA_CMD_???";
> +	}

use ata_get_cmd_descript() rather than duplicating it

> +static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
> +{
> +	int chan;
> +	u32 tfr_reg, err_reg;
> +
> +	struct sata_dwc_device *hsdev =
> +		(struct sata_dwc_device *) hsdev_instance;
> +	struct ata_host *host = (struct ata_host *) hsdev->host;
> +	struct ata_port *ap;
> +	struct sata_dwc_device_port *hsdevp;
> +	u8 tag = 0;
> +	unsigned int port = 0;
> +	struct sata_dwc_host_priv *hp;
> +	hp = kmalloc(sizeof(*hp), GFP_KERNEL);

1) interrupt is not GFP_KERNEL

2) you must failure kmalloc failure

3) it is not clear to me where you initialize this structure???


> +	spin_lock(&host->lock);
> +
> +	ap = host->ports[port];
> +	hsdevp = HSDEVP_FROM_AP(ap);
> +	tag = ap->link.active_tag;
> +
> +	tfr_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.tfr.low));
> +	err_reg = in_le32(&(host_pvt.sata_dma_regs->  \
> +					interrupt_status.error.low));
> +
> +	dev_dbg(ap->dev, "eot=0x%08x err=0x%08x pending=%d active port=%d\n",
> +		tfr_reg, err_reg, hsdevp->dma_pending[tag], port);
> +
> +	for (chan = 0; chan<  DMA_NUM_CHANS; chan++) {
> +		/* Check for end-of-transfer interrupt. */
> +		if (tfr_reg&  DMA_CHANNEL(chan)) {
> +			/* Each DMA command produces 2 interrupts.  Only
> +			 * complete the command after both interrupts have been
> +			 * seen. (See sata_dwc_isr())
> +			 */
> +			hp->dma_interrupt_count++;
> +
> +			sata_dwc_clear_dmacr(hsdevp, tag);
> +
> +			if (hsdevp->dma_pending[tag] ==
> +			    SATA_DWC_DMA_PENDING_NONE) {
> +				dev_err(ap->dev, "DMA not pending eot=0x%08x "
> +					"err=0x%08x tag=0x%02x pending=%d\n",
> +					tfr_reg, err_reg, tag,
> +					hsdevp->dma_pending[tag]);
> +			}
> +
> +			if ((hp->dma_interrupt_count) % 2 == 0)
> +				sata_dwc_dma_xfer_complete(ap, 1);
> +
> +			/* Clear the interrupt */
> +			out_le32(&(host_pvt.sata_dma_regs->  \
> +				interrupt_clear.tfr.low), DMA_CHANNEL(chan));
> +		}
> +
> +		/* Check for error interrupt. */
> +		if (err_reg&  DMA_CHANNEL(chan)) {
> +			/* Error handler ! */
> +			dev_err(ap->dev, "error interrupt err_reg=0x%08x\n",
> +				err_reg);
> +
> +			/* Clear the interrupt. */
> +			out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.\
> +			error.low), DMA_CHANNEL(chan));
> +		}
> +	}
> +
> +	spin_unlock(&host->lock);
> +	kfree(hp);
> +
> +	return IRQ_HANDLED;
> +}

> +static inline void clear_serror(void)
> +{
> +	out_le32((host_pvt.scr_addr_sstatus) + 4,
> +		 in_le32((host_pvt.scr_addr_sstatus) + 4));
> +}

this should be defined in terms of scr_read/write functions defined 
previously.


> +/* See ahci.c */
> +static void sata_dwc_error_intr(struct ata_port *ap,
> +				struct sata_dwc_device *hsdev, uint intpr)
> +{
> +	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
> +	struct ata_eh_info *ehi =&ap->link.eh_info;
> +	unsigned int err_mask = 0, action = 0;
> +	struct ata_queued_cmd *qc;
> +	u32 serror;
> +	u8 status, tag;
> +	u32 err_reg;
> +	struct sata_dwc_host_priv *hp;
> +	hp = kmalloc(sizeof(*hp), GFP_KERNEL);

ditto above 3 comments about 'hp'


> +	ata_ehi_clear_desc(ehi);
> +
> +	serror = core_scr_read(SCR_ERROR);
> +	status = ap->ops->sff_check_status(ap);
> +
> +	err_reg = in_le32(&(host_pvt.sata_dma_regs->  \
> +				interrupt_status.error.low));
> +	tag = ap->link.active_tag;
> +
> +	dev_err(ap->dev, "%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x "
> +		"dma_intp=%d pending=%d issued=%d dma_err_status=0x%08x\n",
> +		__func__, serror, intpr, status, hp->dma_interrupt_count,
> +		hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag], err_reg);
> +
> +	/* Clear error register and interrupt bit */
> +	clear_serror();
> +	clear_interrupt_bit(hsdev, SATA_DWC_INTPR_ERR);
> +
> +	/* This is the only error happening now. */
> +	err_mask |= AC_ERR_HOST_BUS;
> +	action |= ATA_EH_RESET;
> +
> +	/* Pass this on to EH */
> +	ehi->serror |= serror;
> +	ehi->action |= action;
> +
> +	qc = ata_qc_from_tag(ap, tag);
> +	if (qc)
> +		qc->err_mask |= err_mask;
> +	else
> +		ehi->err_mask |= err_mask;
> +
> +	ata_port_abort(ap);
> +	kfree(hp);
> +
> +	/*
> +	  if (irq_stat&  PORT_IRQ_FREEZE)
> +	  ata_port_freeze(ap);
> +	  else
> +	  ata_port_abort(ap);
> +	*/
> +}
> +
> +/*
> + * Function : sata_dwc_isr
> + * arguments : irq, void *dev_instance, struct pt_regs *regs
> + * Return value : irqreturn_t - status of IRQ
> + * This Interrupt handler called via port ops registered function.
> + * .irq_handler = sata_dwc_isr
> + */
> +static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
> +{
> +	u8 status, tag;
> +	int handled, num_processed, port = 0;
> +	uint intpr, sactive, sactive2, tag_mask;
> +	struct sata_dwc_device_port *hsdevp;
> +	struct ata_host *host = (struct ata_host *)dev_instance;
> +	struct sata_dwc_device *hsdev = HSDEV_FROM_HOST(host);
> +	struct ata_port *ap;
> +	struct ata_queued_cmd *qc;
> +	struct sata_dwc_host_priv *hp;
> +
> +	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
> +	hp->sata_dwc_sactive_issued = 0;

ditto above 3 comments about 'hp'


> +	spin_lock(&host->lock);
> +
> +	/* Read the interrupt register */
> +	intpr = in_le32(&hsdev->sata_dwc_regs->intpr);
> +
> +	ap = host->ports[port];
> +	hsdevp = HSDEVP_FROM_AP(ap);
> +
> +	dev_dbg(ap->dev, "%s intpr=0x%08x active_tag=%d\n", __func__, intpr,
> +		ap->link.active_tag);
> +
> +	/* Check for error interrupt */
> +	if (intpr&  SATA_DWC_INTPR_ERR) {
> +		sata_dwc_error_intr(ap, hsdev, intpr);
> +		handled = 1;
> +		goto DONE;
> +	}
> +
> +	/* Check for DMA SETUP FIS (FP DMA) interrupt */
> +	if (intpr&  SATA_DWC_INTPR_NEWFP) {
> +		clear_interrupt_bit(hsdev, SATA_DWC_INTPR_NEWFP);
> +
> +		tag = (u8)(in_le32(&hsdev->sata_dwc_regs->fptagr));
> +		dev_dbg(ap->dev, "%s: NEWFP tag=%d\n", __func__, tag);
> +		if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_PEND)
> +			dev_warn(ap->dev, "CMD tag=%d not pending?\n", tag);
> +
> +		hp->sata_dwc_sactive_issued |= qcmd_tag_to_mask(tag);
> +
> +		qc = ata_qc_from_tag(ap, tag);
> +		/* Start FP DMA for NCQ command.  At this point the tag is the
> +		 * active tag.  It is the tag that matches the command about to
> +		 * be completed.
> +		 */
> +		qc->ap->link.active_tag = tag;
> +		sata_dwc_bmdma_start_by_tag(qc, tag);
> +
> +		handled = 1;
> +		goto DONE;
> +	}
> +	sactive = core_scr_read(SCR_ACTIVE);
> +	tag_mask = (hp->sata_dwc_sactive_issued | sactive) ^ sactive;
> +
> +	/* If no sactive issued and tag_mask is zero then this is not NCQ */
> +	if (hp->sata_dwc_sactive_issued == 0&&  tag_mask == 0) {
> +		if (ap->link.active_tag == ATA_TAG_POISON)
> +			tag = 0;
> +		else
> +			tag = ap->link.active_tag;
> +		qc = ata_qc_from_tag(ap, tag);
> +
> +		/* DEV interrupt w/ no active qc? */
> +		if (unlikely(!qc || (qc->tf.flags&  ATA_TFLAG_POLLING))) {
> +			dev_err(ap->dev, "%s interrupt with no active qc "
> +				"qc=%p\n", __func__, qc);
> +			ata_sff_check_status(ap);
> +			handled = 1;
> +			goto DONE;
> +		}
> +
> +		status = ap->ops->sff_check_status(ap);

either call ->sff_check_status or ata_sff_check_status(), pick one.  in 
above code, you do both.


> +		qc->ap->link.active_tag = tag;
> +		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
> +
> +		if (status&  ATA_ERR) {
> +			dev_dbg(ap->dev, "interrupt ATA_ERR (0x%x)\n", status);
> +			sata_dwc_qc_complete(ap, qc, 1);
> +			handled = 1;
> +			goto DONE;
> +		}
> +
> +		dev_dbg(ap->dev, "%s non-NCQ cmd interrupt, protocol: %s\n",
> +			__func__, prot_2_txt(qc->tf.protocol));
> +DRVSTILLBUSY:
> +		if (ata_is_dma(qc->tf.protocol)) {
> +			/* Each DMA transaction produces 2 interrupts.  The DMAC
> +			 * transfer complete interrupt and the SATA controller
> +			 * operation done interrupt. The command should be
> +			 * completed only after both interrupts are seen.
> +			 */
> +			hp->dma_interrupt_count++;
> +			if (hsdevp->dma_pending[tag] == \
> +					SATA_DWC_DMA_PENDING_NONE) {
> +				dev_err(ap->dev, "%s: DMA not pending "
> +				"intpr=0x%08x status=0x%08x pending=%d\n",
> +				__func__, intpr, status,
> +					hsdevp->dma_pending[tag]);
> +			}
> +
> +			if ((hp->dma_interrupt_count) % 2 == 0)
> +				sata_dwc_dma_xfer_complete(ap, 1);
> +		} else if (ata_is_pio(qc->tf.protocol)) {
> +			ata_sff_hsm_move(ap, qc, status, 0);
> +			handled = 1;
> +			goto DONE;
> +		} else {
> +			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
> +				goto DRVSTILLBUSY;
> +		}
> +
> +		handled = 1;
> +		goto DONE;
> +	}
> +
> +	/*
> +	 * This is NCQ command.  At this point we need to figure out for which
> +	 * tags we have gotten a completion interrupt.  One interrupt may serve
> +	 * as completion for more than one operation when commands are queued
> +	 * (NCQ).  We need to process each completed command.
> +	 */
> +
> +PROCESS:  /* process completed commands */
> +	sactive = core_scr_read(SCR_ACTIVE);
> +	tag_mask = (hp->sata_dwc_sactive_issued | sactive) ^ sactive;
> +
> +	if (sactive != 0 || hp->sata_dwc_sactive_issued>  1 || tag_mask>  1) {
> +		dev_dbg(ap->dev, "%s NCQ:sactive=0x%08x sactive_issued=0x%08x "
> +			"tag_mask=0x%08x\n", __func__, sactive,
> +			hp->sata_dwc_sactive_issued, tag_mask);
> +	}
> +
> +	if ((tag_mask | (hp->sata_dwc_sactive_issued)) != \
> +				(hp->sata_dwc_sactive_issued)) {
> +		dev_warn(ap->dev, "Bad tag mask?  sactive=0x%08x "
> +			 "hp->sata_dwc_sactive_issued=0x%08x tag_mask=0x%08x\n"
> +			 , sactive, hp->sata_dwc_sactive_issued, tag_mask);
> +	}
> +
> +	/* read just to clear ... not bad if currently still busy */
> +	status = ap->ops->sff_check_status(ap);
> +	dev_dbg(ap->dev, "%s ATA status register=0x%x\n", __func__, status);
> +
> +	tag = 0;
> +	num_processed = 0;
> +	while (tag_mask) {
> +		num_processed++;
> +		while (!(tag_mask&  0x00000001)) {
> +			tag++;
> +			tag_mask>>= 1;
> +		}
> +		tag_mask&= (~0x00000001);
> +		qc = ata_qc_from_tag(ap, tag);
> +
> +		/* To be picked up by completion functions */
> +		qc->ap->link.active_tag = tag;
> +		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
> +
> +		/* Let libata/scsi layers handle error */
> +		if (status&  ATA_ERR) {
> +			dev_dbg(ap->dev, "%s ATA_ERR (0x%x)\n", __func__,
> +				status);
> +			sata_dwc_qc_complete(ap, qc, 1);
> +			handled = 1;
> +			goto DONE;
> +		}
> +
> +		/* Process completed command */
> +		dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n", __func__,
> +			prot_2_txt(qc->tf.protocol));
> +		if (ata_is_dma(qc->tf.protocol)) {
> +			hp->dma_interrupt_count++;
> +			if (hsdevp->dma_pending[tag] == \
> +					SATA_DWC_DMA_PENDING_NONE)
> +				dev_warn(ap->dev, "%s: DMA not pending?\n",
> +					__func__);
> +			if ((hp->dma_interrupt_count) % 2 == 0)
> +				sata_dwc_dma_xfer_complete(ap, 1);
> +		} else {
> +			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
> +				goto STILLBUSY;
> +		}
> +		continue;
> +
> +STILLBUSY:
> +		ap->stats.idle_irq++;
> +		dev_warn(ap->dev, "STILL BUSY IRQ ata%d: irq trap\n",
> +			 ap->print_id);
> +	} /* while tag_mask */
> +
> +	/*
> +	 * Check to see if any commands completed while we were processing our
> +	 * initial set of completed commands (reading of status clears
> +	 * interrupts, so we might miss a completed command interrupt if one
> +	 * came in while we were processing --we read status as part of
> +	 * processing a completed command).
> +	 */
> +	sactive2 = core_scr_read(SCR_ACTIVE);
> +	if (sactive2 != sactive) {
> +		dev_dbg(ap->dev, "More completed-sactive=0x%x sactive2=0x%x\n",
> +			sactive, sactive2);
> +		goto PROCESS;

this appears to be a recipe for an infinite loop?


> +/*
> + * Function : sata_dwc_port_start
> + * arguments : struct ata_ioports *port
> + * Return value : returns 0 if success, error code otherwise
> + * This function allocates the scatter gather LLI table for AHB DMA
> + */
> +static int sata_dwc_port_start(struct ata_port *ap)
> +{
> +	int err = 0;
> +	struct sata_dwc_device *hsdev;
> +	struct sata_dwc_device_port *hsdevp = NULL;
> +	struct device *pdev;
> +	u32 sstatus;
> +	int i;
> +
> +	hsdev = HSDEV_FROM_AP(ap);
> +
> +	dev_dbg(ap->dev, "%s: port_no=%d\n", __func__, ap->port_no);
> +
> +	hsdev->host = ap->host;
> +	pdev = ap->host->dev;
> +	if (!pdev) {
> +		dev_err(ap->dev, "%s: no ap->host->dev\n", __func__);
> +		err = -ENODEV;
> +		goto CLEANUP;
> +	}
> +
> +	/* Allocate Port Struct */
> +	hsdevp = kmalloc(sizeof(*hsdevp), GFP_KERNEL);
> +	if (!hsdevp) {
> +		dev_err(ap->dev, "%s: kmalloc failed for hsdevp\n", __func__);
> +		err = -ENOMEM;
> +		goto CLEANUP;
> +	}
> +	memset(hsdevp, 0, sizeof(*hsdevp));

use kzalloc()


> +	/* Clear any error bits before libata starts issuing commands */
> +	clear_serror();
> +
> +	ap->private_data = hsdevp;
> +
> +	/* Are we in Gen I or II */
> +	sstatus = core_scr_read(SCR_STATUS);
> +	switch (SATA_DWC_SCR0_SPD_GET(sstatus)) {
> +	case 0x0:
> +		dev_info(ap->dev, "**** No negotiated speed (nothing attached?"
> +			") ****\n");
> +		break;
> +	case 0x1:
> +		dev_info(ap->dev, "**** GEN I speed rate negotiated ****\n");
> +		break;
> +	case 0x2:
> +		dev_info(ap->dev, "**** GEN II speed rate negotiated ****\n");
> +		break;
> +	}

NAK, libata already prints this out


> +/*
> + * Function : sata_dwc_exec_command_by_tag
> + * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
> + * Return value : None
> + * This function keeps track of individual command tag ids and calls
> + * ata_exec_command in libata
> + */
> +static void sata_dwc_exec_command_by_tag(struct ata_port *ap,
> +					 struct ata_taskfile *tf,
> +					 u8 tag, u32 cmd_issued)
> +{
> +
> +	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
> +
> +	dev_dbg(ap->dev, "%s cmd(0x%02x): %s tag=%d\n", __func__, tf->command,
> +		ata_cmd_2_txt(tf), tag);
> +
> +	spin_lock(&ap->host->lock);
> +	hsdevp->cmd_issued[tag] = cmd_issued;
> +	spin_unlock(&ap->host->lock);

either you need spin_lock_irqsave(), or you don't need the lock at all. 
  investigate which.



> +static void sata_dwc_qc_prep(struct ata_queued_cmd *qc)
> +{
> +	u32 sactive;
> +	u8 tag = qc->tag;
> +
> +	if ((qc->dma_dir == DMA_NONE) || (qc->tf.protocol == ATA_PROT_PIO))
> +		return;
> +
> +#ifdef DEBUG_NCQ
> +	if (qc->tag>  0)
> +		dev_info(qc->ap->dev, "%s: qc->tag=%d ap->active_tag=0x%08x\n",
> +			 __func__, tag, qc->ap->link.active_tag);
> +#endif
> +
> +	if (ata_is_ncq(qc->tf.protocol)) {
> +		sactive = core_scr_read(SCR_ACTIVE);
> +		sactive |= (0x00000001<<  tag);
> +		core_scr_write(SCR_ACTIVE, sactive);
> +		dev_dbg(qc->ap->dev, "%s: tag=%d ap->link.sactive = 0x%08x "
> +		"sactive=0x%08x\n", __func__, tag, qc->ap->link.sactive,
> +		 sactive);
> +	} else {
> +		tag = 0;
> +	}
> +
> +	sata_dwc_qc_prep_by_tag(qc, tag);

qc_prep is for setting up DMA internally, not on the hardware.  SActive 
should be twiddled in qc_issue.



> +static struct scsi_host_template sata_dwc_sht = {
> +	ATA_NCQ_SHT(DRV_NAME),
> +	/*
> +	 * test-only: Currently this driver doesn't handle NCQ
> +	 * correctly. We enable NCQ but set the queue depth to a
> +	 * max of 1. This will get fixed in in a future release.
> +	 */
> +	.sg_tablesize		= LIBATA_MAX_PRD,
> +	.can_queue		= ATA_DEF_QUEUE,	/* ATA_MAX_QUEUE */
> +	.dma_boundary		= ATA_DMA_BOUNDARY,
> +};

What is the problem with NCQ?  It is better to submit a non-NCQ driver 
then, rather than a driver with lots of buggy, unused NCQ code.



> +static const struct ata_port_info sata_dwc_port_info[] = {
> +	{
> +		.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
> +				  ATA_FLAG_MMIO | ATA_FLAG_NCQ,
> +		.pio_mask	= 0x1f,	/* pio 0-4 */
> +		.udma_mask	= ATA_UDMA6,
> +		.port_ops	=&sata_dwc_ops,
> +	},

ditto... don't flag ATA_FLAG_NCQ if you note in the above comment that 
NCQ is broken

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Benjamin Herrenschmidt - April 7, 2010, 7:41 a.m.
On Tue, 2010-04-06 at 11:16 -0400, Jeff Garzik wrote:
> > +static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
> > +{
> > +     int chan;
> > +     u32 tfr_reg, err_reg;
> > +
> > +     struct sata_dwc_device *hsdev =
> > +             (struct sata_dwc_device *) hsdev_instance;
> > +     struct ata_host *host = (struct ata_host *) hsdev->host;
> > +     struct ata_port *ap;
> > +     struct sata_dwc_device_port *hsdevp;
> > +     u8 tag = 0;
> > +     unsigned int port = 0;
> > +     struct sata_dwc_host_priv *hp;
> > +     hp = kmalloc(sizeof(*hp), GFP_KERNEL);
> 
> 1) interrupt is not GFP_KERNEL
> 
> 2) you must failure kmalloc failure
> 
> 3) it is not clear to me where you initialize this structure???

And why the heck would you want to allocate it at interrupt time ? ? ?

BTW. Stefan mentioned earlier that they had some fixes for that driver
in the Denx tree. Are those fixes now included in that variant ?

Cheers,
Ben.


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Rupjyoti Sarmah - April 7, 2010, 7:57 a.m.
Hi Jeff,

Thanks. I would go through your suggestions and resubmit a newer
version.

Regards,
Rup

-----Original Message-----
From: Jeff Garzik [mailto:jgpobox@gmail.com] On Behalf Of Jeff Garzik
Sent: Tuesday, April 06, 2010 8:46 PM
To: Rupjyoti Sarmah
Cc: linux-ide@vger.kernel.org; linux-kernel@vger.kernel.org; sr@denx.de;
linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] 460EX on-chip SATA driver<kernel 2.6.33> <
resubmission : 02>

On 04/06/2010 07:41 AM, Rupjyoti Sarmah wrote:

General comment:  remove "inline" and let the compiler select those 
functions that need it.


> +struct sata_dwc_host_priv {
> +
> +	void __iomem *scr_addr_sstatus;
> +	u32 sata_dwc_sactive_issued;
> +	u32 sata_dwc_sactive_queued;
> +	u32 dma_interrupt_count;
> +	struct ahb_dma_regs *sata_dma_regs;
> +	struct device *dwc_dev;
> +
> +};

use proper indentation (separate type from member name with tabs)


> +struct sata_dwc_host_priv host_pvt;
> +
> +/*
> + * Prototypes
> + */
> +static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8
tag);
> +static int sata_dwc_qc_complete(struct ata_port *ap, struct
ata_queued_cmd *qc,
> +				u32 check_status);
> +static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32
check_status);
> +static void sata_dwc_port_stop(struct ata_port *ap);
> +static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp,
u8 tag);
> +
> +static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq);
> +static void dma_dwc_exit(struct sata_dwc_device *hsdev);
> +static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
> +			      struct lli *lli, dma_addr_t dma_lli,
> +			      void __iomem *addr, int dir);
> +static void dma_dwc_xfer_start(int dma_ch);
> +
> +static const char *dir_2_txt(enum dma_data_direction dir)
> +{
> +	switch (dir) {
> +	case DMA_BIDIRECTIONAL:
> +		return "bi";
> +	case DMA_FROM_DEVICE:
> +		return "from";
> +	case DMA_TO_DEVICE:
> +		return "to";
> +	case DMA_NONE:
> +		return "none";
> +	default:
> +		return "err";
> +	}
> +}
> +
> +static const char *prot_2_txt(enum ata_tf_protocols protocol)
> +{
> +	switch (protocol) {
> +	case ATA_PROT_UNKNOWN:
> +		return "unknown";
> +	case ATA_PROT_NODATA:
> +		return "nodata";
> +	case ATA_PROT_PIO:
> +		return "pio";
> +	case ATA_PROT_DMA:
> +		return "dma";
> +	case ATA_PROT_NCQ:
> +		return "ncq";
> +	case ATAPI_PROT_PIO:
> +		return "atapi pio";
> +	case ATAPI_PROT_NODATA:
> +		return "atapi nodata";
> +	case ATAPI_PROT_DMA:
> +		return "atapi dma";
> +	default:
> +		return "err";
> +	}
> +}
> +
> +inline const char *ata_cmd_2_txt(const struct ata_taskfile *tf)
> +{
> +	switch (tf->command) {
> +	case ATA_CMD_CHK_POWER:
> +		return "ATA_CMD_CHK_POWER";
> +	case ATA_CMD_EDD:
> +		return "ATA_CMD_EDD";
> +	case ATA_CMD_FLUSH:
> +		return "ATA_CMD_FLUSH";
> +	case ATA_CMD_FLUSH_EXT:
> +		return "ATA_CMD_FLUSH_EXT";
> +	case ATA_CMD_ID_ATA:
> +		return "ATA_CMD_ID_ATA";
> +	case ATA_CMD_ID_ATAPI:
> +		return "ATA_CMD_ID_ATAPI";
> +	case ATA_CMD_FPDMA_READ:
> +		return "ATA_CMD_FPDMA_READ";
> +	case ATA_CMD_FPDMA_WRITE:
> +		return "ATA_CMD_FPDMA_WRITE";
> +	case ATA_CMD_READ:
> +		return "ATA_CMD_READ";
> +	case ATA_CMD_READ_EXT:
> +		return "ATA_CMD_READ_EXT";
> +	case ATA_CMD_READ_NATIVE_MAX_EXT:
> +		return "ATA_CMD_READ_NATIVE_MAX_EXT";
> +	case ATA_CMD_VERIFY_EXT:
> +		return "ATA_CMD_VERIFY_EXT";
> +	case ATA_CMD_WRITE:
> +		return "ATA_CMD_WRITE";
> +	case ATA_CMD_WRITE_EXT:
> +		return "ATA_CMD_WRITE_EXT";
> +	case ATA_CMD_PIO_READ:
> +		return "ATA_CMD_PIO_READ";
> +	case ATA_CMD_PIO_READ_EXT:
> +		return "ATA_CMD_PIO_READ_EXT";
> +	case ATA_CMD_PIO_WRITE:
> +		return "ATA_CMD_PIO_WRITE";
> +	case ATA_CMD_PIO_WRITE_EXT:
> +		return "ATA_CMD_PIO_WRITE_EXT";
> +	case ATA_CMD_SET_FEATURES:
> +		return "ATA_CMD_SET_FEATURES";
> +	case ATA_CMD_PACKET:
> +		return "ATA_CMD_PACKET";
> +	default:
> +		return "ATA_CMD_???";
> +	}

use ata_get_cmd_descript() rather than duplicating it

> +static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
> +{
> +	int chan;
> +	u32 tfr_reg, err_reg;
> +
> +	struct sata_dwc_device *hsdev =
> +		(struct sata_dwc_device *) hsdev_instance;
> +	struct ata_host *host = (struct ata_host *) hsdev->host;
> +	struct ata_port *ap;
> +	struct sata_dwc_device_port *hsdevp;
> +	u8 tag = 0;
> +	unsigned int port = 0;
> +	struct sata_dwc_host_priv *hp;
> +	hp = kmalloc(sizeof(*hp), GFP_KERNEL);

1) interrupt is not GFP_KERNEL

2) you must failure kmalloc failure

3) it is not clear to me where you initialize this structure???


> +	spin_lock(&host->lock);
> +
> +	ap = host->ports[port];
> +	hsdevp = HSDEVP_FROM_AP(ap);
> +	tag = ap->link.active_tag;
> +
> +	tfr_reg =
in_le32(&(host_pvt.sata_dma_regs->interrupt_status.tfr.low));
> +	err_reg = in_le32(&(host_pvt.sata_dma_regs->  \
> +					interrupt_status.error.low));
> +
> +	dev_dbg(ap->dev, "eot=0x%08x err=0x%08x pending=%d active
port=%d\n",
> +		tfr_reg, err_reg, hsdevp->dma_pending[tag], port);
> +
> +	for (chan = 0; chan<  DMA_NUM_CHANS; chan++) {
> +		/* Check for end-of-transfer interrupt. */
> +		if (tfr_reg&  DMA_CHANNEL(chan)) {
> +			/* Each DMA command produces 2 interrupts.  Only
> +			 * complete the command after both interrupts
have been
> +			 * seen. (See sata_dwc_isr())
> +			 */
> +			hp->dma_interrupt_count++;
> +
> +			sata_dwc_clear_dmacr(hsdevp, tag);
> +
> +			if (hsdevp->dma_pending[tag] ==
> +			    SATA_DWC_DMA_PENDING_NONE) {
> +				dev_err(ap->dev, "DMA not pending
eot=0x%08x "
> +					"err=0x%08x tag=0x%02x
pending=%d\n",
> +					tfr_reg, err_reg, tag,
> +					hsdevp->dma_pending[tag]);
> +			}
> +
> +			if ((hp->dma_interrupt_count) % 2 == 0)
> +				sata_dwc_dma_xfer_complete(ap, 1);
> +
> +			/* Clear the interrupt */
> +			out_le32(&(host_pvt.sata_dma_regs->  \
> +				interrupt_clear.tfr.low),
DMA_CHANNEL(chan));
> +		}
> +
> +		/* Check for error interrupt. */
> +		if (err_reg&  DMA_CHANNEL(chan)) {
> +			/* Error handler ! */
> +			dev_err(ap->dev, "error interrupt
err_reg=0x%08x\n",
> +				err_reg);
> +
> +			/* Clear the interrupt. */
> +
out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.\
> +			error.low), DMA_CHANNEL(chan));
> +		}
> +	}
> +
> +	spin_unlock(&host->lock);
> +	kfree(hp);
> +
> +	return IRQ_HANDLED;
> +}

> +static inline void clear_serror(void)
> +{
> +	out_le32((host_pvt.scr_addr_sstatus) + 4,
> +		 in_le32((host_pvt.scr_addr_sstatus) + 4));
> +}

this should be defined in terms of scr_read/write functions defined 
previously.


> +/* See ahci.c */
> +static void sata_dwc_error_intr(struct ata_port *ap,
> +				struct sata_dwc_device *hsdev, uint
intpr)
> +{
> +	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
> +	struct ata_eh_info *ehi =&ap->link.eh_info;
> +	unsigned int err_mask = 0, action = 0;
> +	struct ata_queued_cmd *qc;
> +	u32 serror;
> +	u8 status, tag;
> +	u32 err_reg;
> +	struct sata_dwc_host_priv *hp;
> +	hp = kmalloc(sizeof(*hp), GFP_KERNEL);

ditto above 3 comments about 'hp'


> +	ata_ehi_clear_desc(ehi);
> +
> +	serror = core_scr_read(SCR_ERROR);
> +	status = ap->ops->sff_check_status(ap);
> +
> +	err_reg = in_le32(&(host_pvt.sata_dma_regs->  \
> +				interrupt_status.error.low));
> +	tag = ap->link.active_tag;
> +
> +	dev_err(ap->dev, "%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x
"
> +		"dma_intp=%d pending=%d issued=%d
dma_err_status=0x%08x\n",
> +		__func__, serror, intpr, status,
hp->dma_interrupt_count,
> +		hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag],
err_reg);
> +
> +	/* Clear error register and interrupt bit */
> +	clear_serror();
> +	clear_interrupt_bit(hsdev, SATA_DWC_INTPR_ERR);
> +
> +	/* This is the only error happening now. */
> +	err_mask |= AC_ERR_HOST_BUS;
> +	action |= ATA_EH_RESET;
> +
> +	/* Pass this on to EH */
> +	ehi->serror |= serror;
> +	ehi->action |= action;
> +
> +	qc = ata_qc_from_tag(ap, tag);
> +	if (qc)
> +		qc->err_mask |= err_mask;
> +	else
> +		ehi->err_mask |= err_mask;
> +
> +	ata_port_abort(ap);
> +	kfree(hp);
> +
> +	/*
> +	  if (irq_stat&  PORT_IRQ_FREEZE)
> +	  ata_port_freeze(ap);
> +	  else
> +	  ata_port_abort(ap);
> +	*/
> +}
> +
> +/*
> + * Function : sata_dwc_isr
> + * arguments : irq, void *dev_instance, struct pt_regs *regs
> + * Return value : irqreturn_t - status of IRQ
> + * This Interrupt handler called via port ops registered function.
> + * .irq_handler = sata_dwc_isr
> + */
> +static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
> +{
> +	u8 status, tag;
> +	int handled, num_processed, port = 0;
> +	uint intpr, sactive, sactive2, tag_mask;
> +	struct sata_dwc_device_port *hsdevp;
> +	struct ata_host *host = (struct ata_host *)dev_instance;
> +	struct sata_dwc_device *hsdev = HSDEV_FROM_HOST(host);
> +	struct ata_port *ap;
> +	struct ata_queued_cmd *qc;
> +	struct sata_dwc_host_priv *hp;
> +
> +	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
> +	hp->sata_dwc_sactive_issued = 0;

ditto above 3 comments about 'hp'


> +	spin_lock(&host->lock);
> +
> +	/* Read the interrupt register */
> +	intpr = in_le32(&hsdev->sata_dwc_regs->intpr);
> +
> +	ap = host->ports[port];
> +	hsdevp = HSDEVP_FROM_AP(ap);
> +
> +	dev_dbg(ap->dev, "%s intpr=0x%08x active_tag=%d\n", __func__,
intpr,
> +		ap->link.active_tag);
> +
> +	/* Check for error interrupt */
> +	if (intpr&  SATA_DWC_INTPR_ERR) {
> +		sata_dwc_error_intr(ap, hsdev, intpr);
> +		handled = 1;
> +		goto DONE;
> +	}
> +
> +	/* Check for DMA SETUP FIS (FP DMA) interrupt */
> +	if (intpr&  SATA_DWC_INTPR_NEWFP) {
> +		clear_interrupt_bit(hsdev, SATA_DWC_INTPR_NEWFP);
> +
> +		tag = (u8)(in_le32(&hsdev->sata_dwc_regs->fptagr));
> +		dev_dbg(ap->dev, "%s: NEWFP tag=%d\n", __func__, tag);
> +		if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_PEND)
> +			dev_warn(ap->dev, "CMD tag=%d not pending?\n",
tag);
> +
> +		hp->sata_dwc_sactive_issued |= qcmd_tag_to_mask(tag);
> +
> +		qc = ata_qc_from_tag(ap, tag);
> +		/* Start FP DMA for NCQ command.  At this point the tag
is the
> +		 * active tag.  It is the tag that matches the command
about to
> +		 * be completed.
> +		 */
> +		qc->ap->link.active_tag = tag;
> +		sata_dwc_bmdma_start_by_tag(qc, tag);
> +
> +		handled = 1;
> +		goto DONE;
> +	}
> +	sactive = core_scr_read(SCR_ACTIVE);
> +	tag_mask = (hp->sata_dwc_sactive_issued | sactive) ^ sactive;
> +
> +	/* If no sactive issued and tag_mask is zero then this is not
NCQ */
> +	if (hp->sata_dwc_sactive_issued == 0&&  tag_mask == 0) {
> +		if (ap->link.active_tag == ATA_TAG_POISON)
> +			tag = 0;
> +		else
> +			tag = ap->link.active_tag;
> +		qc = ata_qc_from_tag(ap, tag);
> +
> +		/* DEV interrupt w/ no active qc? */
> +		if (unlikely(!qc || (qc->tf.flags&  ATA_TFLAG_POLLING)))
{
> +			dev_err(ap->dev, "%s interrupt with no active qc
"
> +				"qc=%p\n", __func__, qc);
> +			ata_sff_check_status(ap);
> +			handled = 1;
> +			goto DONE;
> +		}
> +
> +		status = ap->ops->sff_check_status(ap);

either call ->sff_check_status or ata_sff_check_status(), pick one.  in 
above code, you do both.


> +		qc->ap->link.active_tag = tag;
> +		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
> +
> +		if (status&  ATA_ERR) {
> +			dev_dbg(ap->dev, "interrupt ATA_ERR (0x%x)\n",
status);
> +			sata_dwc_qc_complete(ap, qc, 1);
> +			handled = 1;
> +			goto DONE;
> +		}
> +
> +		dev_dbg(ap->dev, "%s non-NCQ cmd interrupt, protocol:
%s\n",
> +			__func__, prot_2_txt(qc->tf.protocol));
> +DRVSTILLBUSY:
> +		if (ata_is_dma(qc->tf.protocol)) {
> +			/* Each DMA transaction produces 2 interrupts.
The DMAC
> +			 * transfer complete interrupt and the SATA
controller
> +			 * operation done interrupt. The command should
be
> +			 * completed only after both interrupts are
seen.
> +			 */
> +			hp->dma_interrupt_count++;
> +			if (hsdevp->dma_pending[tag] == \
> +					SATA_DWC_DMA_PENDING_NONE) {
> +				dev_err(ap->dev, "%s: DMA not pending "
> +				"intpr=0x%08x status=0x%08x
pending=%d\n",
> +				__func__, intpr, status,
> +					hsdevp->dma_pending[tag]);
> +			}
> +
> +			if ((hp->dma_interrupt_count) % 2 == 0)
> +				sata_dwc_dma_xfer_complete(ap, 1);
> +		} else if (ata_is_pio(qc->tf.protocol)) {
> +			ata_sff_hsm_move(ap, qc, status, 0);
> +			handled = 1;
> +			goto DONE;
> +		} else {
> +			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
> +				goto DRVSTILLBUSY;
> +		}
> +
> +		handled = 1;
> +		goto DONE;
> +	}
> +
> +	/*
> +	 * This is NCQ command.  At this point we need to figure out for
which
> +	 * tags we have gotten a completion interrupt.  One interrupt
may serve
> +	 * as completion for more than one operation when commands are
queued
> +	 * (NCQ).  We need to process each completed command.
> +	 */
> +
> +PROCESS:  /* process completed commands */
> +	sactive = core_scr_read(SCR_ACTIVE);
> +	tag_mask = (hp->sata_dwc_sactive_issued | sactive) ^ sactive;
> +
> +	if (sactive != 0 || hp->sata_dwc_sactive_issued>  1 || tag_mask>
1) {
> +		dev_dbg(ap->dev, "%s NCQ:sactive=0x%08x
sactive_issued=0x%08x "
> +			"tag_mask=0x%08x\n", __func__, sactive,
> +			hp->sata_dwc_sactive_issued, tag_mask);
> +	}
> +
> +	if ((tag_mask | (hp->sata_dwc_sactive_issued)) != \
> +				(hp->sata_dwc_sactive_issued)) {
> +		dev_warn(ap->dev, "Bad tag mask?  sactive=0x%08x "
> +			 "hp->sata_dwc_sactive_issued=0x%08x
tag_mask=0x%08x\n"
> +			 , sactive, hp->sata_dwc_sactive_issued,
tag_mask);
> +	}
> +
> +	/* read just to clear ... not bad if currently still busy */
> +	status = ap->ops->sff_check_status(ap);
> +	dev_dbg(ap->dev, "%s ATA status register=0x%x\n", __func__,
status);
> +
> +	tag = 0;
> +	num_processed = 0;
> +	while (tag_mask) {
> +		num_processed++;
> +		while (!(tag_mask&  0x00000001)) {
> +			tag++;
> +			tag_mask>>= 1;
> +		}
> +		tag_mask&= (~0x00000001);
> +		qc = ata_qc_from_tag(ap, tag);
> +
> +		/* To be picked up by completion functions */
> +		qc->ap->link.active_tag = tag;
> +		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
> +
> +		/* Let libata/scsi layers handle error */
> +		if (status&  ATA_ERR) {
> +			dev_dbg(ap->dev, "%s ATA_ERR (0x%x)\n",
__func__,
> +				status);
> +			sata_dwc_qc_complete(ap, qc, 1);
> +			handled = 1;
> +			goto DONE;
> +		}
> +
> +		/* Process completed command */
> +		dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n",
__func__,
> +			prot_2_txt(qc->tf.protocol));
> +		if (ata_is_dma(qc->tf.protocol)) {
> +			hp->dma_interrupt_count++;
> +			if (hsdevp->dma_pending[tag] == \
> +					SATA_DWC_DMA_PENDING_NONE)
> +				dev_warn(ap->dev, "%s: DMA not
pending?\n",
> +					__func__);
> +			if ((hp->dma_interrupt_count) % 2 == 0)
> +				sata_dwc_dma_xfer_complete(ap, 1);
> +		} else {
> +			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
> +				goto STILLBUSY;
> +		}
> +		continue;
> +
> +STILLBUSY:
> +		ap->stats.idle_irq++;
> +		dev_warn(ap->dev, "STILL BUSY IRQ ata%d: irq trap\n",
> +			 ap->print_id);
> +	} /* while tag_mask */
> +
> +	/*
> +	 * Check to see if any commands completed while we were
processing our
> +	 * initial set of completed commands (reading of status clears
> +	 * interrupts, so we might miss a completed command interrupt if
one
> +	 * came in while we were processing --we read status as part of
> +	 * processing a completed command).
> +	 */
> +	sactive2 = core_scr_read(SCR_ACTIVE);
> +	if (sactive2 != sactive) {
> +		dev_dbg(ap->dev, "More completed-sactive=0x%x
sactive2=0x%x\n",
> +			sactive, sactive2);
> +		goto PROCESS;

this appears to be a recipe for an infinite loop?


> +/*
> + * Function : sata_dwc_port_start
> + * arguments : struct ata_ioports *port
> + * Return value : returns 0 if success, error code otherwise
> + * This function allocates the scatter gather LLI table for AHB DMA
> + */
> +static int sata_dwc_port_start(struct ata_port *ap)
> +{
> +	int err = 0;
> +	struct sata_dwc_device *hsdev;
> +	struct sata_dwc_device_port *hsdevp = NULL;
> +	struct device *pdev;
> +	u32 sstatus;
> +	int i;
> +
> +	hsdev = HSDEV_FROM_AP(ap);
> +
> +	dev_dbg(ap->dev, "%s: port_no=%d\n", __func__, ap->port_no);
> +
> +	hsdev->host = ap->host;
> +	pdev = ap->host->dev;
> +	if (!pdev) {
> +		dev_err(ap->dev, "%s: no ap->host->dev\n", __func__);
> +		err = -ENODEV;
> +		goto CLEANUP;
> +	}
> +
> +	/* Allocate Port Struct */
> +	hsdevp = kmalloc(sizeof(*hsdevp), GFP_KERNEL);
> +	if (!hsdevp) {
> +		dev_err(ap->dev, "%s: kmalloc failed for hsdevp\n",
__func__);
> +		err = -ENOMEM;
> +		goto CLEANUP;
> +	}
> +	memset(hsdevp, 0, sizeof(*hsdevp));

use kzalloc()


> +	/* Clear any error bits before libata starts issuing commands */
> +	clear_serror();
> +
> +	ap->private_data = hsdevp;
> +
> +	/* Are we in Gen I or II */
> +	sstatus = core_scr_read(SCR_STATUS);
> +	switch (SATA_DWC_SCR0_SPD_GET(sstatus)) {
> +	case 0x0:
> +		dev_info(ap->dev, "**** No negotiated speed (nothing
attached?"
> +			") ****\n");
> +		break;
> +	case 0x1:
> +		dev_info(ap->dev, "**** GEN I speed rate negotiated
****\n");
> +		break;
> +	case 0x2:
> +		dev_info(ap->dev, "**** GEN II speed rate negotiated
****\n");
> +		break;
> +	}

NAK, libata already prints this out


> +/*
> + * Function : sata_dwc_exec_command_by_tag
> + * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
> + * Return value : None
> + * This function keeps track of individual command tag ids and calls
> + * ata_exec_command in libata
> + */
> +static void sata_dwc_exec_command_by_tag(struct ata_port *ap,
> +					 struct ata_taskfile *tf,
> +					 u8 tag, u32 cmd_issued)
> +{
> +
> +	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
> +
> +	dev_dbg(ap->dev, "%s cmd(0x%02x): %s tag=%d\n", __func__,
tf->command,
> +		ata_cmd_2_txt(tf), tag);
> +
> +	spin_lock(&ap->host->lock);
> +	hsdevp->cmd_issued[tag] = cmd_issued;
> +	spin_unlock(&ap->host->lock);

either you need spin_lock_irqsave(), or you don't need the lock at all. 
  investigate which.



> +static void sata_dwc_qc_prep(struct ata_queued_cmd *qc)
> +{
> +	u32 sactive;
> +	u8 tag = qc->tag;
> +
> +	if ((qc->dma_dir == DMA_NONE) || (qc->tf.protocol ==
ATA_PROT_PIO))
> +		return;
> +
> +#ifdef DEBUG_NCQ
> +	if (qc->tag>  0)
> +		dev_info(qc->ap->dev, "%s: qc->tag=%d
ap->active_tag=0x%08x\n",
> +			 __func__, tag, qc->ap->link.active_tag);
> +#endif
> +
> +	if (ata_is_ncq(qc->tf.protocol)) {
> +		sactive = core_scr_read(SCR_ACTIVE);
> +		sactive |= (0x00000001<<  tag);
> +		core_scr_write(SCR_ACTIVE, sactive);
> +		dev_dbg(qc->ap->dev, "%s: tag=%d ap->link.sactive =
0x%08x "
> +		"sactive=0x%08x\n", __func__, tag, qc->ap->link.sactive,
> +		 sactive);
> +	} else {
> +		tag = 0;
> +	}
> +
> +	sata_dwc_qc_prep_by_tag(qc, tag);

qc_prep is for setting up DMA internally, not on the hardware.  SActive 
should be twiddled in qc_issue.



> +static struct scsi_host_template sata_dwc_sht = {
> +	ATA_NCQ_SHT(DRV_NAME),
> +	/*
> +	 * test-only: Currently this driver doesn't handle NCQ
> +	 * correctly. We enable NCQ but set the queue depth to a
> +	 * max of 1. This will get fixed in in a future release.
> +	 */
> +	.sg_tablesize		= LIBATA_MAX_PRD,
> +	.can_queue		= ATA_DEF_QUEUE,	/* ATA_MAX_QUEUE
*/
> +	.dma_boundary		= ATA_DMA_BOUNDARY,
> +};

What is the problem with NCQ?  It is better to submit a non-NCQ driver 
then, rather than a driver with lots of buggy, unused NCQ code.



> +static const struct ata_port_info sata_dwc_port_info[] = {
> +	{
> +		.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
> +				  ATA_FLAG_MMIO | ATA_FLAG_NCQ,
> +		.pio_mask	= 0x1f,	/* pio 0-4 */
> +		.udma_mask	= ATA_UDMA6,
> +		.port_ops	=&sata_dwc_ops,
> +	},

ditto... don't flag ATA_FLAG_NCQ if you note in the above comment that 
NCQ is broken

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Stefan Roese - April 7, 2010, 8:22 a.m.
On Wednesday 07 April 2010 09:41:56 Benjamin Herrenschmidt wrote:
> BTW. Stefan mentioned earlier that they had some fixes for that driver
> in the Denx tree. Are those fixes now included in that variant ?

Yes, from a first scan the fix I was referring to seems to be included.

Cheers,
Stefan
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Patch

diff --git a/arch/powerpc/boot/dts/canyonlands.dts b/arch/powerpc/boot/dts/canyonlands.dts
index cd56bb5..d3b2c99 100644
--- a/arch/powerpc/boot/dts/canyonlands.dts
+++ b/arch/powerpc/boot/dts/canyonlands.dts
@@ -163,6 +163,14 @@ 
 			interrupts = <0x1e 4>;
 		};
 
+		SATA0: sata@bffd1000 {
+                        compatible = "amcc,sata-460ex";
+			reg = <4 0xbffd1000 0x800 4 0xbffd0800 0x400>;
+                        interrupt-parent = <&UIC3>;
+                        interrupts = <0x0 0x4       /* SATA */
+                                      0x5 0x4>;     /* AHBDMA */
+                };
+
 		POB0: opb {
 			compatible = "ibm,opb-460ex", "ibm,opb";
 			#address-cells = <1>;
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 56c6374..bba7b8a 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -82,6 +82,15 @@  config SATA_FSL
 
 	  If unsure, say N.
 
+config SATA_DWC
+	tristate "DesignWare Cores SATA support"
+	depends on 460EX
+	help
+	  This option enables support for the on-chip SATA controller of the
+	  AppliedMicro processor 460EX.
+
+	  If unsure, say N.
+
 config ATA_SFF
 	bool "ATA SFF support"
 	default y
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index fc936d4..0de7a33 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -19,6 +19,7 @@  obj-$(CONFIG_SATA_INIC162X)	+= sata_inic162x.o
 obj-$(CONFIG_PDC_ADMA)		+= pdc_adma.o
 obj-$(CONFIG_SATA_FSL)		+= sata_fsl.o
 obj-$(CONFIG_PATA_MACIO)	+= pata_macio.o
+obj-$(CONFIG_SATA_DWC)		+= sata_dwc.o
 
 obj-$(CONFIG_PATA_ALI)		+= pata_ali.o
 obj-$(CONFIG_PATA_AMD)		+= pata_amd.o
diff --git a/drivers/ata/sata_dwc.c b/drivers/ata/sata_dwc.c
new file mode 100644
index 0000000..28c227e
--- /dev/null
+++ b/drivers/ata/sata_dwc.c
@@ -0,0 +1,1965 @@ 
+/*
+ * drivers/ata/sata_dwc.c
+ *
+ * Synopsys DesignWare Cores (DWC) SATA host driver
+ *
+ * Author: Mark Miesfeld <mmiesfeld@appliedmicro.com>
+ *
+ * Ported from 2.6.19.2 to 2.6.25/26 by Stefan Roese <sr@denx.de>
+ * Copyright 2008 DENX Software Engineering
+ *
+ * Based on versions provided by AMCC and Synopsys which are:
+ *          Copyright 2006 Applied Micro Circuits Corporation
+ *          COPYRIGHT (C) 2005  SYNOPSYS, INC.  ALL RIGHTS RESERVED
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ *
+ */
+
+#ifdef CONFIG_SATA_DWC_DEBUG
+#define DEBUG
+#endif
+
+#ifdef CONFIG_SATA_DWC_VDEBUG
+#define VERBOSE_DEBUG
+#define DEBUG_NCQ
+#endif
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/of_platform.h>
+#include <linux/libata.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_cmnd.h>
+
+#define DRV_NAME        "sata-dwc"
+#define DRV_VERSION     "1.0"
+
+/* SATA DMA driver Globals */
+#define DMA_NUM_CHANS			1
+#define DMA_NUM_CHAN_REGS		8
+
+/* SATA DMA Register definitions */
+#define AHB_DMA_BRST_DFLT		64 /* 16 data items burst length */
+
+struct dmareg {
+	u32 low;		/* Low bits 0-31 */
+	u32 high;		/* High bits 32-63 */
+};
+
+/* DMA Per Channel registers */
+
+struct dma_chan_regs {
+	struct dmareg sar;	/* Source Address */
+	struct dmareg dar;	/* Destination address */
+	struct dmareg llp;	/* Linked List Pointer */
+	struct dmareg ctl;	/* Control */
+	struct dmareg sstat;	/* Source Status not implemented in core */
+	struct dmareg dstat;	/* DestinationStatus not implemented in core */
+	struct dmareg sstatar;	/* Source Status Address not impl in core */
+	struct dmareg dstatar;	/* DestinationStatus Address not implemented */
+	struct dmareg cfg;	/* Config */
+	struct dmareg sgr;	/* Source Gather */
+	struct dmareg dsr;	/* Destination Scatter */
+};
+
+/* Generic Interrupt Registers */
+struct dma_interrupt_regs {
+	struct dmareg tfr;	/* Transfer Interrupt */
+	struct dmareg block;	/* Block Interrupt */
+	struct dmareg srctran;	/* Source Transfer Interrupt */
+	struct dmareg dsttran;	/* Dest Transfer Interrupt */
+	struct dmareg error;	/* Error */
+};
+
+struct ahb_dma_regs {
+	struct dma_chan_regs	chan_regs[DMA_NUM_CHAN_REGS];/* channel reg */
+	struct dma_interrupt_regs interrupt_raw;	/* Raw Interrupt */
+	struct dma_interrupt_regs interrupt_status;	/* Interrupt Status */
+	struct dma_interrupt_regs interrupt_mask;	/* Interrupt Mask */
+	struct dma_interrupt_regs interrupt_clear;	/* Interrupt Clear */
+	struct dmareg		statusInt;		/* Interrupt combined */
+	struct dmareg		rq_srcreg;		/* Src Trans Req */
+	struct dmareg		rq_dstreg;		/* Dst Trans Req */
+	struct dmareg		rq_sgl_srcreg;		/* Sngl Src Trans Req */
+	struct dmareg		rq_sgl_dstreg;		/* Sngl Dst Trans Req */
+	struct dmareg		rq_lst_srcreg;		/* Last Src Trans Req */
+	struct dmareg		rq_lst_dstreg;		/* Last Dst Trans Req */
+	struct dmareg		dma_cfg;		/* DMA Config */
+	struct dmareg		dma_chan_en;		/* DMA Channel Enable */
+	struct dmareg		dma_id;			/* DMA ID */
+	struct dmareg		dma_test;		/* DMA Test */
+	struct dmareg		res1;			/* reserved */
+	struct dmareg		res2;			/* reserved */
+
+	/* DMA Comp Params
+	 * Param 6 = dma_param[0], Param 5 = dma_param[1],
+	 * Param 4 = dma_param[2] ...
+	 */
+	struct dmareg		dma_params[6];
+};
+
+/* Data structure for linked list item */
+struct lli {
+	u32		sar;		/* Source Address */
+	u32		dar;		/* Destination address */
+	u32		llp;		/* Linked List Pointer */
+	struct dmareg	ctl;		/* Control */
+	struct dmareg	dstat;		/* Destination Status */
+};
+
+enum {
+	SATA_DWC_DMAC_LLI_SZ =	(sizeof(struct lli)),
+	SATA_DWC_DMAC_LLI_NUM =	256,
+	SATA_DWC_DMAC_LLI_TBL_SZ = (SATA_DWC_DMAC_LLI_SZ * \
+					SATA_DWC_DMAC_LLI_NUM),
+	SATA_DWC_DMAC_TWIDTH_BYTES = 4,
+	SATA_DWC_DMAC_CTRL_TSIZE_MAX = (0x00000800 * \
+						SATA_DWC_DMAC_TWIDTH_BYTES),
+};
+
+/* DMA Register Operation Bits */
+
+enum {
+	DMA_EN	=		0x00000001, /* Enable AHB DMA */
+	/* Control Register */
+
+	DMA_CTL_LLP_SRCEN =	0x10000000, /* Blk chain enable Src */
+	DMA_CTL_LLP_DSTEN =	0x08000000, /* Blk chain enable Dst */
+};
+
+#define	DMA_CTL_BLK_TS(size)	((size) & 0x000000FFF)	/* Blk Transfer size */
+#define DMA_CHANNEL(ch) 	(0x00000001 << (ch))	/* Select channel */
+	/* Enable channel */
+#define	DMA_ENABLE_CHAN(ch)	((0x00000001 << (ch)) |			\
+				 ((0x000000001 << (ch)) << 8))
+	/* Disable channel */
+#define	DMA_DISABLE_CHAN(ch)	(0x00000000 | ((0x000000001 << (ch)) << 8))
+	/* Transfer Type & Flow Controller */
+#define	DMA_CTL_TTFC(type)	(((type) & 0x7) << 20)
+#define	DMA_CTL_SMS(num)	(((num) & 0x3) << 25) /* Src Master Select */
+#define	DMA_CTL_DMS(num)	(((num) & 0x3) << 23)/* Dst Master Select */
+	/* Src Burst Transaction Length */
+#define DMA_CTL_SRC_MSIZE(size) (((size) & 0x7) << 14)
+	/* Dst Burst Transaction Length */
+#define	DMA_CTL_DST_MSIZE(size) (((size) & 0x7) << 11)
+	/* Source Transfer Width */
+#define	DMA_CTL_SRC_TRWID(size) (((size) & 0x7) << 4)
+	/* Destination Transfer Width */
+#define	DMA_CTL_DST_TRWID(size) (((size) & 0x7) << 1)
+
+/* Assign HW handshaking interface (x) to destination / source peripheral */
+#define	DMA_CFG_HW_HS_DEST(int_num) (((int_num) & 0xF) << 11)
+#define	DMA_CFG_HW_HS_SRC(int_num) (((int_num) & 0xF) << 7)
+#define	DMA_LLP_LMS(addr, master) (((addr) & 0xfffffffc) | (master))
+
+/*
+ * This define is used to set block chaining disabled in the control low
+ * register.  It is already in little endian format so it can be &'d dirctly.
+ * It is essentially: cpu_to_le32(~(DMA_CTL_LLP_SRCEN | DMA_CTL_LLP_DSTEN))
+ */
+enum {
+	DMA_CTL_LLP_DISABLE_LE32 = 0xffffffe7,
+	DMA_CTL_TTFC_P2M_DMAC =	0x00000002, /* Per to mem, DMAC cntr */
+	DMA_CTL_TTFC_M2P_PER =	0x00000003, /* Mem to per, peripheral cntr */
+	DMA_CTL_SINC_INC =	0x00000000, /* Source Address Increment */
+	DMA_CTL_SINC_DEC =	0x00000200,
+	DMA_CTL_SINC_NOCHANGE =	0x00000400,
+	DMA_CTL_DINC_INC =	0x00000000, /* Destination Address Increment */
+	DMA_CTL_DINC_DEC =	0x00000080,
+	DMA_CTL_DINC_NOCHANGE =	0x00000100,
+	DMA_CTL_INT_EN =	0x00000001, /* Interrupt Enable */
+
+/* Channel Configuration Register high bits */
+	DMA_CFG_FCMOD_REQ =	0x00000001, /* Flow Control - request based */
+	DMA_CFG_PROTCTL	=	(0x00000003 << 2),/* Protection Control */
+
+/* Channel Configuration Register low bits */
+	DMA_CFG_RELD_DST =	0x80000000, /* Reload Dest / Src Addr */
+	DMA_CFG_RELD_SRC =	0x40000000,
+	DMA_CFG_HS_SELSRC =	0x00000800, /* Software handshake Src/ Dest */
+	DMA_CFG_HS_SELDST =	0x00000400,
+	DMA_CFG_FIFOEMPTY =     (0x00000001 << 9), /* FIFO Empty bit */
+
+
+/* Channel Linked List Pointer Register */
+
+	DMA_LLP_AHBMASTER1 =	0,	/* List Master Select */
+	DMA_LLP_AHBMASTER2 =	1,
+
+	SATA_DWC_MAX_PORTS = 1,
+
+	SATA_DWC_SCR_OFFSET = 0x24,
+	SATA_DWC_REG_OFFSET = 0x64,
+
+};
+
+/* DWC SATA Registers */
+struct sata_dwc_regs {
+	u32 fptagr;		/* 1st party DMA tag */
+	u32 fpbor;		/* 1st party DMA buffer offset */
+	u32 fptcr;		/* 1st party DMA Xfr count */
+	u32 dmacr;		/* DMA Control */
+	u32 dbtsr;		/* DMA Burst Transac size */
+	u32 intpr;		/* Interrupt Pending */
+	u32 intmr;		/* Interrupt Mask */
+	u32 errmr;		/* Error Mask */
+	u32 llcr;		/* Link Layer Control */
+	u32 phycr;		/* PHY Control */
+	u32 physr;		/* PHY Status */
+	u32 rxbistpd;		/* Recvd BIST pattern def register */
+	u32 rxbistpd1;		/* Recvd BIST data dword1 */
+	u32 rxbistpd2;		/* Recvd BIST pattern data dword2 */
+	u32 txbistpd;		/* Trans BIST pattern def register */
+	u32 txbistpd1;		/* Trans BIST data dword1 */
+	u32 txbistpd2;		/* Trans BIST data dword2 */
+	u32 bistcr;		/* BIST Control Register */
+	u32 bistfctr;		/* BIST FIS Count Register */
+	u32 bistsr;		/* BIST Status Register */
+	u32 bistdecr;		/* BIST Dword Error count register */
+	u32 res[15];		/* Reserved locations */
+	u32 testr;		/* Test Register */
+	u32 versionr;		/* Version Register */
+	u32 idr;		/* ID Register */
+	u32 unimpl[192];	/* Unimplemented */
+	u32 dmadr[256];	/* FIFO Locations in DMA Mode */
+};
+
+enum {
+	SCR_SCONTROL_DET_ENABLE	=	0x00000001,
+	SCR_SSTATUS_DET_PRESENT	=	0x00000001,
+	SCR_SERROR_DIAG_X	=	0x04000000,
+
+/* DWC SATA Register Operations */
+	SATA_DWC_TXFIFO_DEPTH	=	0x01FF,
+	SATA_DWC_RXFIFO_DEPTH	=	0x01FF,
+
+	SATA_DWC_DMACR_TMOD_TXCHEN =	0x00000004,
+	SATA_DWC_DMACR_TXCHEN	= (0x00000001 | SATA_DWC_DMACR_TMOD_TXCHEN),
+	SATA_DWC_DMACR_RXCHEN	= (0x00000002 | SATA_DWC_DMACR_TMOD_TXCHEN),
+
+	SATA_DWC_DMACR_TXRXCH_CLEAR =	SATA_DWC_DMACR_TMOD_TXCHEN,
+
+
+	SATA_DWC_INTPR_DMAT	=	0x00000001,
+	SATA_DWC_INTPR_NEWFP	=	0x00000002,
+	SATA_DWC_INTPR_PMABRT	=	0x00000004,
+	SATA_DWC_INTPR_ERR	=	0x00000008,
+	SATA_DWC_INTPR_NEWBIST	=	0x00000010,
+	SATA_DWC_INTPR_IPF	=	0x10000000,
+	SATA_DWC_INTMR_DMATM	=	0x00000001,
+	SATA_DWC_INTMR_NEWFPM	=	0x00000002,
+	SATA_DWC_INTMR_PMABRTM	=	0x00000004,
+	SATA_DWC_INTMR_ERRM	=	0x00000008,
+	SATA_DWC_INTMR_NEWBISTM	=	0x00000010,
+	SATA_DWC_LLCR_SCRAMEN	=	0x00000001,
+	SATA_DWC_LLCR_DESCRAMEN	=	0x00000002,
+	SATA_DWC_LLCR_RPDEN	=	0x00000004,
+
+/* This is all error bits, zero's are reserved fields. */
+	SATA_DWC_SERROR_ERR_BITS =	0x0FFF0F03
+
+};
+
+#define SATA_DWC_SCR0_SPD_GET(v)	(((v) >> 4) & 0x0000000F)
+#define SATA_DWC_DMACR_TX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_TXCHEN) |\
+						 SATA_DWC_DMACR_TMOD_TXCHEN)
+#define SATA_DWC_DMACR_RX_CLEAR(v)	(((v) & ~SATA_DWC_DMACR_RXCHEN) |\
+						 SATA_DWC_DMACR_TMOD_TXCHEN)
+#define SATA_DWC_DBTSR_MWR(size)	(((size)/4) & SATA_DWC_TXFIFO_DEPTH)
+#define SATA_DWC_DBTSR_MRD(size)	((((size)/4) & SATA_DWC_RXFIFO_DEPTH)\
+						 << 16)
+
+
+struct sata_dwc_device {
+	struct device		*dev;		/* generic device struct */
+	struct ata_probe_ent	*pe;		/* ptr to probe-ent */
+	struct ata_host		*host;
+	u8			*reg_base;
+	struct sata_dwc_regs	*sata_dwc_regs;	/* DW Synopsys SATA specific */
+	int			irq_dma;
+};
+
+#define SATA_DWC_QCMD_MAX	32
+
+struct sata_dwc_device_port {
+	struct sata_dwc_device	*hsdev;
+	int			cmd_issued[SATA_DWC_QCMD_MAX];
+	struct lli		*llit[SATA_DWC_QCMD_MAX];
+	dma_addr_t		llit_dma[SATA_DWC_QCMD_MAX];
+	u32			dma_chan[SATA_DWC_QCMD_MAX];
+	int			dma_pending[SATA_DWC_QCMD_MAX];
+};
+
+/*
+ * Commonly used DWC SATA driver Macros
+ */
+#define HSDEV_FROM_HOST(host)  ((struct sata_dwc_device *)\
+					(host)->private_data)
+#define HSDEV_FROM_AP(ap)  ((struct sata_dwc_device *)\
+					(ap)->host->private_data)
+#define HSDEVP_FROM_AP(ap)   ((struct sata_dwc_device_port *)\
+					(ap)->private_data)
+#define HSDEV_FROM_QC(qc)	((struct sata_dwc_device *)\
+					(qc)->ap->host->private_data)
+#define HSDEV_FROM_HSDEVP(p)	((struct sata_dwc_device *)\
+						(hsdevp)->hsdev)
+
+enum {
+	SATA_DWC_CMD_ISSUED_NOT		= 0,
+	SATA_DWC_CMD_ISSUED_PEND	= 1,
+	SATA_DWC_CMD_ISSUED_EXEC	= 2,
+	SATA_DWC_CMD_ISSUED_NODATA	= 3,
+
+	SATA_DWC_DMA_PENDING_NONE	= 0,
+	SATA_DWC_DMA_PENDING_TX		= 1,
+	SATA_DWC_DMA_PENDING_RX		= 2,
+};
+
+
+struct sata_dwc_host_priv {
+
+	void __iomem *scr_addr_sstatus;
+	u32 sata_dwc_sactive_issued;
+	u32 sata_dwc_sactive_queued;
+	u32 dma_interrupt_count;
+	struct ahb_dma_regs *sata_dma_regs;
+	struct device *dwc_dev;
+
+};
+
+struct sata_dwc_host_priv host_pvt;
+
+/*
+ * Prototypes
+ */
+static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag);
+static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
+				u32 check_status);
+static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
+static void sata_dwc_port_stop(struct ata_port *ap);
+static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);
+
+static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq);
+static void dma_dwc_exit(struct sata_dwc_device *hsdev);
+static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
+			      struct lli *lli, dma_addr_t dma_lli,
+			      void __iomem *addr, int dir);
+static void dma_dwc_xfer_start(int dma_ch);
+
+static const char *dir_2_txt(enum dma_data_direction dir)
+{
+	switch (dir) {
+	case DMA_BIDIRECTIONAL:
+		return "bi";
+	case DMA_FROM_DEVICE:
+		return "from";
+	case DMA_TO_DEVICE:
+		return "to";
+	case DMA_NONE:
+		return "none";
+	default:
+		return "err";
+	}
+}
+
+static const char *prot_2_txt(enum ata_tf_protocols protocol)
+{
+	switch (protocol) {
+	case ATA_PROT_UNKNOWN:
+		return "unknown";
+	case ATA_PROT_NODATA:
+		return "nodata";
+	case ATA_PROT_PIO:
+		return "pio";
+	case ATA_PROT_DMA:
+		return "dma";
+	case ATA_PROT_NCQ:
+		return "ncq";
+	case ATAPI_PROT_PIO:
+		return "atapi pio";
+	case ATAPI_PROT_NODATA:
+		return "atapi nodata";
+	case ATAPI_PROT_DMA:
+		return "atapi dma";
+	default:
+		return "err";
+	}
+}
+
+inline const char *ata_cmd_2_txt(const struct ata_taskfile *tf)
+{
+	switch (tf->command) {
+	case ATA_CMD_CHK_POWER:
+		return "ATA_CMD_CHK_POWER";
+	case ATA_CMD_EDD:
+		return "ATA_CMD_EDD";
+	case ATA_CMD_FLUSH:
+		return "ATA_CMD_FLUSH";
+	case ATA_CMD_FLUSH_EXT:
+		return "ATA_CMD_FLUSH_EXT";
+	case ATA_CMD_ID_ATA:
+		return "ATA_CMD_ID_ATA";
+	case ATA_CMD_ID_ATAPI:
+		return "ATA_CMD_ID_ATAPI";
+	case ATA_CMD_FPDMA_READ:
+		return "ATA_CMD_FPDMA_READ";
+	case ATA_CMD_FPDMA_WRITE:
+		return "ATA_CMD_FPDMA_WRITE";
+	case ATA_CMD_READ:
+		return "ATA_CMD_READ";
+	case ATA_CMD_READ_EXT:
+		return "ATA_CMD_READ_EXT";
+	case ATA_CMD_READ_NATIVE_MAX_EXT:
+		return "ATA_CMD_READ_NATIVE_MAX_EXT";
+	case ATA_CMD_VERIFY_EXT:
+		return "ATA_CMD_VERIFY_EXT";
+	case ATA_CMD_WRITE:
+		return "ATA_CMD_WRITE";
+	case ATA_CMD_WRITE_EXT:
+		return "ATA_CMD_WRITE_EXT";
+	case ATA_CMD_PIO_READ:
+		return "ATA_CMD_PIO_READ";
+	case ATA_CMD_PIO_READ_EXT:
+		return "ATA_CMD_PIO_READ_EXT";
+	case ATA_CMD_PIO_WRITE:
+		return "ATA_CMD_PIO_WRITE";
+	case ATA_CMD_PIO_WRITE_EXT:
+		return "ATA_CMD_PIO_WRITE_EXT";
+	case ATA_CMD_SET_FEATURES:
+		return "ATA_CMD_SET_FEATURES";
+	case ATA_CMD_PACKET:
+		return "ATA_CMD_PACKET";
+	default:
+		return "ATA_CMD_???";
+	}
+}
+
+static void sata_dwc_tf_dump(struct ata_taskfile *tf)
+{
+
+	dev_vdbg(host_pvt.dwc_dev, "taskfile cmd: 0x%02x protocol: %s flags: "
+		"0x%lx device: %x\n", tf->command, prot_2_txt(tf->protocol),
+		tf->flags, tf->device);
+	dev_vdbg(host_pvt.dwc_dev, "feature: 0x%02x nsect: 0x%x lbal: 0x%x "
+		"lbam: 0x%x lbah: 0x%x\n", tf->feature, tf->nsect, tf->lbal,
+		tf->lbam, tf->lbah);
+	dev_vdbg(host_pvt.dwc_dev, "hob_feature:0x%02x hob_nsect:0x%x hob_lbal"
+		": 0x%x hob_lbam: 0x%x hob_lbah: 0x%x\n", tf->hob_feature,
+		tf->hob_nsect, tf->hob_lbal, tf->hob_lbam, tf->hob_lbah);
+}
+/*
+ * Function: get_burst_length_encode
+ * arguments: datalength: length in bytes of data
+ * returns value to be programmed in register corrresponding to data length
+ * This value is effectively the log(base 2) of the length
+ */
+static inline int get_burst_length_encode(int datalength)
+{
+	int items = datalength >> 2;	/* div by 4 to get lword count */
+
+	if (items >= 64)
+		return 5;
+
+	if (items >= 32)
+		return 4;
+
+	if (items >= 16)
+		return 3;
+
+	if (items >= 8)
+		return 2;
+
+	if (items >= 4)
+		return 1;
+
+	return 0;
+}
+
+static inline void clear_chan_interrupts(int c)
+{
+	out_le32(&host_pvt.sata_dma_regs->interrupt_clear.tfr.low,
+		 DMA_CHANNEL(c));
+	out_le32(&host_pvt.sata_dma_regs->interrupt_clear.block.low,
+		 DMA_CHANNEL(c));
+	out_le32(&host_pvt.sata_dma_regs->interrupt_clear.srctran.low,
+		 DMA_CHANNEL(c));
+	out_le32(&host_pvt.sata_dma_regs->interrupt_clear.dsttran.low,
+		 DMA_CHANNEL(c));
+	out_le32(&host_pvt.sata_dma_regs->interrupt_clear.error.low,
+		 DMA_CHANNEL(c));
+}
+
+/*
+ * Function: dma_request_channel
+ * arguments: None
+ * returns channel number if available else -1
+ * This function assigns the next available DMA channel from the list to the
+ * requester
+ */
+static int dma_request_channel(void)
+{
+	int i;
+
+	for (i = 0; i < DMA_NUM_CHANS; i++) {
+		if (!(in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)) & \
+				DMA_CHANNEL(i)))
+			return i;
+	}
+
+	/* warn of channel info */
+	dev_err(host_pvt.dwc_dev, "%s NO channel chan_en: 0x%08x\n", __func__,
+		in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)));
+
+	return -1;
+}
+
+/*
+ * Function: dma_dwc_interrupt
+ * arguments: irq, dev_id, pt_regs
+ * returns channel number if available else -1
+ * Interrupt Handler for DW AHB SATA DMA
+ */
+static irqreturn_t dma_dwc_interrupt(int irq, void *hsdev_instance)
+{
+	int chan;
+	u32 tfr_reg, err_reg;
+
+	struct sata_dwc_device *hsdev =
+		(struct sata_dwc_device *) hsdev_instance;
+	struct ata_host *host = (struct ata_host *) hsdev->host;
+	struct ata_port *ap;
+	struct sata_dwc_device_port *hsdevp;
+	u8 tag = 0;
+	unsigned int port = 0;
+	struct sata_dwc_host_priv *hp;
+	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+
+	spin_lock(&host->lock);
+
+	ap = host->ports[port];
+	hsdevp = HSDEVP_FROM_AP(ap);
+	tag = ap->link.active_tag;
+
+	tfr_reg = in_le32(&(host_pvt.sata_dma_regs->interrupt_status.tfr.low));
+	err_reg = in_le32(&(host_pvt.sata_dma_regs-> \
+					interrupt_status.error.low));
+
+	dev_dbg(ap->dev, "eot=0x%08x err=0x%08x pending=%d active port=%d\n",
+		tfr_reg, err_reg, hsdevp->dma_pending[tag], port);
+
+	for (chan = 0; chan < DMA_NUM_CHANS; chan++) {
+		/* Check for end-of-transfer interrupt. */
+		if (tfr_reg & DMA_CHANNEL(chan)) {
+			/* Each DMA command produces 2 interrupts.  Only
+			 * complete the command after both interrupts have been
+			 * seen. (See sata_dwc_isr())
+			 */
+			hp->dma_interrupt_count++;
+
+			sata_dwc_clear_dmacr(hsdevp, tag);
+
+			if (hsdevp->dma_pending[tag] ==
+			    SATA_DWC_DMA_PENDING_NONE) {
+				dev_err(ap->dev, "DMA not pending eot=0x%08x "
+					"err=0x%08x tag=0x%02x pending=%d\n",
+					tfr_reg, err_reg, tag,
+					hsdevp->dma_pending[tag]);
+			}
+
+			if ((hp->dma_interrupt_count) % 2 == 0)
+				sata_dwc_dma_xfer_complete(ap, 1);
+
+			/* Clear the interrupt */
+			out_le32(&(host_pvt.sata_dma_regs-> \
+				interrupt_clear.tfr.low), DMA_CHANNEL(chan));
+		}
+
+		/* Check for error interrupt. */
+		if (err_reg & DMA_CHANNEL(chan)) {
+			/* Error handler ! */
+			dev_err(ap->dev, "error interrupt err_reg=0x%08x\n",
+				err_reg);
+
+			/* Clear the interrupt. */
+			out_le32(&(host_pvt.sata_dma_regs->interrupt_clear.\
+			error.low), DMA_CHANNEL(chan));
+		}
+	}
+
+	spin_unlock(&host->lock);
+	kfree(hp);
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Function: dma_request_interrupts
+ * arguments: hsdev
+ * returns status
+ * This function registers ISR for a particular DMA channel interrupt
+ */
+static int dma_request_interrupts(struct sata_dwc_device *hsdev, int irq)
+{
+	int retval = 0;
+	int chan;
+
+	for (chan = 0; chan < DMA_NUM_CHANS; chan++) {
+		/* Unmask error interrupt */
+		out_le32(&(host_pvt.sata_dma_regs)->interrupt_mask.error.low,
+			 DMA_ENABLE_CHAN(chan));
+
+		/* Unmask end-of-transfer interrupt */
+		out_le32(&(host_pvt.sata_dma_regs)->interrupt_mask.tfr.low,
+			 DMA_ENABLE_CHAN(chan));
+	}
+
+	retval = request_irq(irq, dma_dwc_interrupt, 0, "SATA DMA", hsdev);
+	if (retval) {
+		dev_err(host_pvt.dwc_dev, "%s: No IRQ %d\n", __func__, irq);
+		return -ENODEV;
+	}
+
+	/* Mark this interrupt as requested */
+	hsdev->irq_dma = irq;
+
+	return 0;
+}
+
+/*
+ * Function: map_sg_to_lli
+ * arguments: sg: scatter/gather list(sg)
+ *	      num_elems: no of elements in sg list
+ *	      dma_lli: LLI table
+ *	      dest: destination address
+ *	      read: whether the transfer is read or write
+ * returns array of AHB DMA Linked List Items
+ * This function creates a list of LLIs for DMA Xfr and returns the number
+ * of elements in the DMA linked list.
+ *
+ * Note that the Synopsis driver did comment proposing that better performance
+ * is possible by only enabling interrupts on the last item in the linked list.
+ * However, it seems that could be a problem if an error happened on one of the
+ * first items.  The transfer would halt, but no error interrupt would occur.
+ *
+ * Currently this function sets interrupts enabled for each linked list item:
+ * DMA_CTL_INT_EN.
+ */
+static int map_sg_to_lli(struct scatterlist *sg, int num_elems, struct lli *lli
+		, dma_addr_t dma_lli, void __iomem *dmadr_addr, int dir)
+{
+	int i, idx = 0;
+	int fis_len = 0;
+	dma_addr_t next_llp;
+	int bl;
+
+	dev_dbg(host_pvt.dwc_dev, "%s: sg=%p nelem=%d lli=%p dma_lli=0x%08x\n",
+		__func__, sg, num_elems, lli, (u32)dma_lli);
+
+	bl = get_burst_length_encode(AHB_DMA_BRST_DFLT);
+
+	for (i = 0; i < num_elems; i++, sg++) {
+		u32 addr, offset;
+		u32 sg_len, len;
+
+		addr = (u32) sg_dma_address(sg);
+		sg_len = sg_dma_len(sg);
+
+		dev_dbg(host_pvt.dwc_dev, "%s: elem=%d sg_addr=0x%x sg_len"
+			"=%d\n", __func__, i, addr, sg_len);
+
+		while (sg_len) {
+
+			if (idx >= SATA_DWC_DMAC_LLI_NUM) {
+				/* The LLI table is not large enough. */
+				dev_err(host_pvt.dwc_dev, "LLI table overrun "
+					"(idx=%d)\n", idx);
+				break;
+			}
+			len = (sg_len > SATA_DWC_DMAC_CTRL_TSIZE_MAX) ?
+				SATA_DWC_DMAC_CTRL_TSIZE_MAX : sg_len;
+
+			offset = addr & 0xffff;
+			if ((offset + sg_len) > 0x10000)
+				len = 0x10000 - offset;
+
+			/*
+			 * Make sure a LLI block is not created that will span a
+			 * 8K max FIS boundary.  If the block spans such a FIS
+			 * boundary, there is a chance that a DMA burst will
+			 * cross that boundary -- this results in an error in
+			 * the host controller.
+			 */
+			if (fis_len + len > 8192) {
+				dev_dbg(host_pvt.dwc_dev, "SPLITTING: fis_len"
+					"=%d(0x%x)len=%d(0x%x)\n", fis_len,
+					fis_len, len, len);
+				len = 8192 - fis_len;
+				fis_len = 0;
+			} else {
+				fis_len += len;
+			}
+			if (fis_len == 8192)
+				fis_len = 0;
+
+			/*
+			 * Set DMA addresses and lower half of control register
+			 * based on direction.
+			 */
+			if (dir == DMA_FROM_DEVICE) {
+				lli[idx].dar = cpu_to_le32(addr);
+				lli[idx].sar = cpu_to_le32((u32)dmadr_addr);
+
+				lli[idx].ctl.low = cpu_to_le32(
+					DMA_CTL_TTFC(DMA_CTL_TTFC_P2M_DMAC) |
+					DMA_CTL_SMS(0) |
+					DMA_CTL_DMS(1) |
+					DMA_CTL_SRC_MSIZE(bl) |
+					DMA_CTL_DST_MSIZE(bl) |
+					DMA_CTL_SINC_NOCHANGE |
+					DMA_CTL_SRC_TRWID(2) |
+					DMA_CTL_DST_TRWID(2) |
+					DMA_CTL_INT_EN |
+					DMA_CTL_LLP_SRCEN |
+					DMA_CTL_LLP_DSTEN);
+			} else {	/* DMA_TO_DEVICE */
+				lli[idx].sar = cpu_to_le32(addr);
+				lli[idx].dar = cpu_to_le32((u32)dmadr_addr);
+
+				lli[idx].ctl.low = cpu_to_le32(
+					DMA_CTL_TTFC(DMA_CTL_TTFC_M2P_PER) |
+					DMA_CTL_SMS(1) |
+					DMA_CTL_DMS(0) |
+					DMA_CTL_SRC_MSIZE(bl) |
+					DMA_CTL_DST_MSIZE(bl) |
+					DMA_CTL_DINC_NOCHANGE |
+					DMA_CTL_SRC_TRWID(2) |
+					DMA_CTL_DST_TRWID(2) |
+					DMA_CTL_INT_EN |
+					DMA_CTL_LLP_SRCEN |
+					DMA_CTL_LLP_DSTEN);
+			}
+
+			dev_dbg(host_pvt.dwc_dev, "%s setting ctl.high len: "
+				"0x%08x val: 0x%08x\n",	__func__, len,
+				DMA_CTL_BLK_TS(len / 4));
+
+			/* Program the LLI CTL high register */
+			lli[idx].ctl.high = cpu_to_le32(DMA_CTL_BLK_TS \
+						(len / 4));
+
+			/* Program the next pointer.  The next pointer must be
+			 * the physical address, not the virtual address.
+			 */
+			next_llp = (dma_lli + ((idx + 1) * \
+						sizeof(struct lli)));
+
+			/* The last 2 bits encode the list master select. */
+			next_llp = DMA_LLP_LMS(next_llp, DMA_LLP_AHBMASTER2);
+
+			lli[idx].llp = cpu_to_le32(next_llp);
+
+			idx++;
+			sg_len -= len;
+			addr += len;
+		}
+	}
+
+	/*
+	 * The last next ptr has to be zero and the last control low register
+	 * has to have LLP_SRC_EN and LLP_DST_EN (linked list pointer source
+	 * and destination enable) set back to 0 (disabled.) This is what tells
+	 * the core that this is the last item in the linked list.
+	 */
+	if (idx) {
+		lli[idx-1].llp = 0x00000000;
+		lli[idx-1].ctl.low &= DMA_CTL_LLP_DISABLE_LE32;
+
+		/* Flush cache to memory */
+		dma_cache_sync(NULL, lli, (sizeof(struct lli) * idx),
+			       DMA_BIDIRECTIONAL);
+	}
+
+	return idx;
+}
+
+/*
+ * Function: dma_dwc_xfer_start
+ * arguments: Channel number
+ * Return : None
+ * Enables the DMA channel
+ */
+static void dma_dwc_xfer_start(int dma_ch)
+{
+	/* Enable the DMA channel */
+	out_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low),
+		 in_le32(&(host_pvt.sata_dma_regs->dma_chan_en.low)) |
+		 DMA_ENABLE_CHAN(dma_ch));
+
+}
+
+
+static int dma_dwc_xfer_setup(struct scatterlist *sg, int num_elems,
+			      struct lli *lli, dma_addr_t dma_lli,
+			      void __iomem *addr, int dir)
+{
+	int dma_ch;
+	int num_lli;
+
+	/* Acquire DMA channel */
+	dma_ch = dma_request_channel();
+	if (dma_ch == -1) {
+		dev_err(host_pvt.dwc_dev, "%s: dma channel unavailable\n",
+			 __func__);
+		return -EAGAIN;
+	}
+
+	/* Convert SG list to linked list of items (LLIs) for AHB DMA */
+	num_lli = map_sg_to_lli(sg, num_elems, lli, dma_lli, addr, dir);
+
+	dev_dbg(host_pvt.dwc_dev, "%s sg: 0x%p, count: %d lli: %p dma_lli:"
+		"0x%0xlx addr: %p lli count: %d\n", __func__, sg, num_elems,
+		 lli, (u32)dma_lli, addr, num_lli);
+
+	/* Clear channel interrupts */
+	clear_chan_interrupts(dma_ch);
+
+	/* Program the CFG register. */
+	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].cfg.high),
+		 DMA_CFG_PROTCTL | DMA_CFG_FCMOD_REQ);
+	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].cfg.low), 0);
+
+	/* Program the address of the linked list */
+	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].llp.low),
+		 DMA_LLP_LMS(dma_lli, DMA_LLP_AHBMASTER2));
+
+	/* Program the CTL register with src enable / dst enable */
+	out_le32(&(host_pvt.sata_dma_regs->chan_regs[dma_ch].ctl.low),
+		 DMA_CTL_LLP_SRCEN | DMA_CTL_LLP_DSTEN);
+
+	return 0;
+}
+
+/*
+ * Function: dma_dwc_exit
+ * arguments: None
+ * returns status
+ * This function exits the SATA DMA driver
+ */
+static void dma_dwc_exit(struct sata_dwc_device *hsdev)
+{
+	dev_dbg(host_pvt.dwc_dev, "%s:\n", __func__);
+	if (host_pvt.sata_dma_regs)
+		iounmap(host_pvt.sata_dma_regs);
+
+	if (hsdev->irq_dma)
+		free_irq(hsdev->irq_dma, hsdev);
+}
+
+/*
+ * Function: dma_dwc_init
+ * arguments: hsdev
+ * returns status
+ * This function initializes the SATA DMA driver
+ */
+static int dma_dwc_init(struct sata_dwc_device *hsdev, int irq)
+{
+	int err;
+	err = dma_request_interrupts(hsdev, irq);
+	if (err) {
+		dev_err(host_pvt.dwc_dev, "%s: dma_request_interrupts"
+			" returns %d\n", __func__, err);
+		goto error_out;
+	}
+
+	/* Enabe DMA */
+	out_le32(&(host_pvt.sata_dma_regs->dma_cfg.low), DMA_EN);
+
+	dev_notice(host_pvt.dwc_dev, "DMA initialized\n");
+	dev_dbg(host_pvt.dwc_dev, "SATA DMA registers=0x%p\n",
+		host_pvt.sata_dma_regs);
+
+	return 0;
+
+error_out:
+	dma_dwc_exit(hsdev);
+
+	return err;
+}
+
+static int sata_dwc_scr_read(struct ata_link *link, unsigned int scr, u32 *val)
+{
+	if (scr > SCR_NOTIFICATION) {
+		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
+			__func__, scr);
+		return -EINVAL;
+	}
+
+	*val = in_le32((void *)link->ap->ioaddr.scr_addr + (scr * 4));
+	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=val=0x%08x\n",
+		__func__, link->ap->print_id, scr, *val);
+
+	return 0;
+}
+
+static int sata_dwc_scr_write(struct ata_link *link, unsigned int scr, u32 val)
+{
+	dev_dbg(link->ap->dev, "%s: id=%d reg=%d val=val=0x%08x\n",
+		__func__, link->ap->print_id, scr, val);
+	if (scr > SCR_NOTIFICATION) {
+		dev_err(link->ap->dev, "%s: Incorrect SCR offset 0x%02x\n",
+			__func__, scr);
+		return -EINVAL;
+	}
+	out_le32((void *)link->ap->ioaddr.scr_addr + (scr * 4), val);
+
+	return 0;
+}
+
+static inline u32 core_scr_read(unsigned int scr)
+{
+	return in_le32((host_pvt.scr_addr_sstatus) + (scr * 4));
+}
+
+static inline void core_scr_write(unsigned int scr, u32 val)
+{
+	out_le32((host_pvt.scr_addr_sstatus) + (scr * 4), val);
+}
+
+static inline void clear_serror(void)
+{
+	out_le32((host_pvt.scr_addr_sstatus) + 4,
+		 in_le32((host_pvt.scr_addr_sstatus) + 4));
+}
+
+static inline void clear_intpr(struct sata_dwc_device *hsdev)
+{
+	out_le32(&hsdev->sata_dwc_regs->intpr,
+		 in_le32(&hsdev->sata_dwc_regs->intpr));
+}
+
+static inline void clear_interrupt_bit(struct sata_dwc_device *hsdev, u32 bit)
+{
+	out_le32(&hsdev->sata_dwc_regs->intpr,
+		 in_le32(&hsdev->sata_dwc_regs->intpr));
+}
+
+static inline void disable_err_irq(struct sata_dwc_device *hsdev)
+{
+	out_le32(&hsdev->sata_dwc_regs->intmr,
+		 in_le32(&hsdev->sata_dwc_regs->intmr) & ~SATA_DWC_INTMR_ERRM);
+	out_le32(&hsdev->sata_dwc_regs->errmr, ~SATA_DWC_SERROR_ERR_BITS);
+}
+
+static inline void enable_err_irq(struct sata_dwc_device *hsdev)
+{
+	out_le32(&hsdev->sata_dwc_regs->intmr,
+		 in_le32(&hsdev->sata_dwc_regs->intmr) | SATA_DWC_INTMR_ERRM);
+	out_le32(&hsdev->sata_dwc_regs->errmr, SATA_DWC_SERROR_ERR_BITS);
+}
+
+static inline u32 qcmd_tag_to_mask(u8 tag)
+{
+	return 0x00000001 << (tag & 0x1f);
+}
+
+/* See ahci.c */
+static void sata_dwc_error_intr(struct ata_port *ap,
+				struct sata_dwc_device *hsdev, uint intpr)
+{
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+	struct ata_eh_info *ehi = &ap->link.eh_info;
+	unsigned int err_mask = 0, action = 0;
+	struct ata_queued_cmd *qc;
+	u32 serror;
+	u8 status, tag;
+	u32 err_reg;
+	struct sata_dwc_host_priv *hp;
+	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+
+	ata_ehi_clear_desc(ehi);
+
+	serror = core_scr_read(SCR_ERROR);
+	status = ap->ops->sff_check_status(ap);
+
+	err_reg = in_le32(&(host_pvt.sata_dma_regs-> \
+				interrupt_status.error.low));
+	tag = ap->link.active_tag;
+
+	dev_err(ap->dev, "%s SCR_ERROR=0x%08x intpr=0x%08x status=0x%08x "
+		"dma_intp=%d pending=%d issued=%d dma_err_status=0x%08x\n",
+		__func__, serror, intpr, status, hp->dma_interrupt_count,
+		hsdevp->dma_pending[tag], hsdevp->cmd_issued[tag], err_reg);
+
+	/* Clear error register and interrupt bit */
+	clear_serror();
+	clear_interrupt_bit(hsdev, SATA_DWC_INTPR_ERR);
+
+	/* This is the only error happening now. */
+	err_mask |= AC_ERR_HOST_BUS;
+	action |= ATA_EH_RESET;
+
+	/* Pass this on to EH */
+	ehi->serror |= serror;
+	ehi->action |= action;
+
+	qc = ata_qc_from_tag(ap, tag);
+	if (qc)
+		qc->err_mask |= err_mask;
+	else
+		ehi->err_mask |= err_mask;
+
+	ata_port_abort(ap);
+	kfree(hp);
+
+	/*
+	  if (irq_stat & PORT_IRQ_FREEZE)
+	  ata_port_freeze(ap);
+	  else
+	  ata_port_abort(ap);
+	*/
+}
+
+/*
+ * Function : sata_dwc_isr
+ * arguments : irq, void *dev_instance, struct pt_regs *regs
+ * Return value : irqreturn_t - status of IRQ
+ * This Interrupt handler called via port ops registered function.
+ * .irq_handler = sata_dwc_isr
+ */
+static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
+{
+	u8 status, tag;
+	int handled, num_processed, port = 0;
+	uint intpr, sactive, sactive2, tag_mask;
+	struct sata_dwc_device_port *hsdevp;
+	struct ata_host *host = (struct ata_host *)dev_instance;
+	struct sata_dwc_device *hsdev = HSDEV_FROM_HOST(host);
+	struct ata_port *ap;
+	struct ata_queued_cmd *qc;
+	struct sata_dwc_host_priv *hp;
+
+	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+	hp->sata_dwc_sactive_issued = 0;
+
+	spin_lock(&host->lock);
+
+	/* Read the interrupt register */
+	intpr = in_le32(&hsdev->sata_dwc_regs->intpr);
+
+	ap = host->ports[port];
+	hsdevp = HSDEVP_FROM_AP(ap);
+
+	dev_dbg(ap->dev, "%s intpr=0x%08x active_tag=%d\n", __func__, intpr,
+		ap->link.active_tag);
+
+	/* Check for error interrupt */
+	if (intpr & SATA_DWC_INTPR_ERR) {
+		sata_dwc_error_intr(ap, hsdev, intpr);
+		handled = 1;
+		goto DONE;
+	}
+
+	/* Check for DMA SETUP FIS (FP DMA) interrupt */
+	if (intpr & SATA_DWC_INTPR_NEWFP) {
+		clear_interrupt_bit(hsdev, SATA_DWC_INTPR_NEWFP);
+
+		tag = (u8)(in_le32(&hsdev->sata_dwc_regs->fptagr));
+		dev_dbg(ap->dev, "%s: NEWFP tag=%d\n", __func__, tag);
+		if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_PEND)
+			dev_warn(ap->dev, "CMD tag=%d not pending?\n", tag);
+
+		hp->sata_dwc_sactive_issued |= qcmd_tag_to_mask(tag);
+
+		qc = ata_qc_from_tag(ap, tag);
+		/* Start FP DMA for NCQ command.  At this point the tag is the
+		 * active tag.  It is the tag that matches the command about to
+		 * be completed.
+		 */
+		qc->ap->link.active_tag = tag;
+		sata_dwc_bmdma_start_by_tag(qc, tag);
+
+		handled = 1;
+		goto DONE;
+	}
+	sactive = core_scr_read(SCR_ACTIVE);
+	tag_mask = (hp->sata_dwc_sactive_issued | sactive) ^ sactive;
+
+	/* If no sactive issued and tag_mask is zero then this is not NCQ */
+	if (hp->sata_dwc_sactive_issued == 0 && tag_mask == 0) {
+		if (ap->link.active_tag == ATA_TAG_POISON)
+			tag = 0;
+		else
+			tag = ap->link.active_tag;
+		qc = ata_qc_from_tag(ap, tag);
+
+		/* DEV interrupt w/ no active qc? */
+		if (unlikely(!qc || (qc->tf.flags & ATA_TFLAG_POLLING))) {
+			dev_err(ap->dev, "%s interrupt with no active qc "
+				"qc=%p\n", __func__, qc);
+			ata_sff_check_status(ap);
+			handled = 1;
+			goto DONE;
+		}
+
+		status = ap->ops->sff_check_status(ap);
+
+		qc->ap->link.active_tag = tag;
+		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
+
+		if (status & ATA_ERR) {
+			dev_dbg(ap->dev, "interrupt ATA_ERR (0x%x)\n", status);
+			sata_dwc_qc_complete(ap, qc, 1);
+			handled = 1;
+			goto DONE;
+		}
+
+		dev_dbg(ap->dev, "%s non-NCQ cmd interrupt, protocol: %s\n",
+			__func__, prot_2_txt(qc->tf.protocol));
+DRVSTILLBUSY:
+		if (ata_is_dma(qc->tf.protocol)) {
+			/* Each DMA transaction produces 2 interrupts.  The DMAC
+			 * transfer complete interrupt and the SATA controller
+			 * operation done interrupt. The command should be
+			 * completed only after both interrupts are seen.
+			 */
+			hp->dma_interrupt_count++;
+			if (hsdevp->dma_pending[tag] == \
+					SATA_DWC_DMA_PENDING_NONE) {
+				dev_err(ap->dev, "%s: DMA not pending "
+				"intpr=0x%08x status=0x%08x pending=%d\n",
+				__func__, intpr, status,
+					hsdevp->dma_pending[tag]);
+			}
+
+			if ((hp->dma_interrupt_count) % 2 == 0)
+				sata_dwc_dma_xfer_complete(ap, 1);
+		} else if (ata_is_pio(qc->tf.protocol)) {
+			ata_sff_hsm_move(ap, qc, status, 0);
+			handled = 1;
+			goto DONE;
+		} else {
+			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
+				goto DRVSTILLBUSY;
+		}
+
+		handled = 1;
+		goto DONE;
+	}
+
+	/*
+	 * This is NCQ command.  At this point we need to figure out for which
+	 * tags we have gotten a completion interrupt.  One interrupt may serve
+	 * as completion for more than one operation when commands are queued
+	 * (NCQ).  We need to process each completed command.
+	 */
+
+PROCESS:  /* process completed commands */
+	sactive = core_scr_read(SCR_ACTIVE);
+	tag_mask = (hp->sata_dwc_sactive_issued | sactive) ^ sactive;
+
+	if (sactive != 0 || hp->sata_dwc_sactive_issued > 1 || tag_mask > 1) {
+		dev_dbg(ap->dev, "%s NCQ:sactive=0x%08x sactive_issued=0x%08x "
+			"tag_mask=0x%08x\n", __func__, sactive,
+			hp->sata_dwc_sactive_issued, tag_mask);
+	}
+
+	if ((tag_mask | (hp->sata_dwc_sactive_issued)) != \
+				(hp->sata_dwc_sactive_issued)) {
+		dev_warn(ap->dev, "Bad tag mask?  sactive=0x%08x "
+			 "hp->sata_dwc_sactive_issued=0x%08x tag_mask=0x%08x\n"
+			 , sactive, hp->sata_dwc_sactive_issued, tag_mask);
+	}
+
+	/* read just to clear ... not bad if currently still busy */
+	status = ap->ops->sff_check_status(ap);
+	dev_dbg(ap->dev, "%s ATA status register=0x%x\n", __func__, status);
+
+	tag = 0;
+	num_processed = 0;
+	while (tag_mask) {
+		num_processed++;
+		while (!(tag_mask & 0x00000001)) {
+			tag++;
+			tag_mask >>= 1;
+		}
+		tag_mask &= (~0x00000001);
+		qc = ata_qc_from_tag(ap, tag);
+
+		/* To be picked up by completion functions */
+		qc->ap->link.active_tag = tag;
+		hsdevp->cmd_issued[tag] = SATA_DWC_CMD_ISSUED_NOT;
+
+		/* Let libata/scsi layers handle error */
+		if (status & ATA_ERR) {
+			dev_dbg(ap->dev, "%s ATA_ERR (0x%x)\n", __func__,
+				status);
+			sata_dwc_qc_complete(ap, qc, 1);
+			handled = 1;
+			goto DONE;
+		}
+
+		/* Process completed command */
+		dev_dbg(ap->dev, "%s NCQ command, protocol: %s\n", __func__,
+			prot_2_txt(qc->tf.protocol));
+		if (ata_is_dma(qc->tf.protocol)) {
+			hp->dma_interrupt_count++;
+			if (hsdevp->dma_pending[tag] == \
+					SATA_DWC_DMA_PENDING_NONE)
+				dev_warn(ap->dev, "%s: DMA not pending?\n",
+					__func__);
+			if ((hp->dma_interrupt_count) % 2 == 0)
+				sata_dwc_dma_xfer_complete(ap, 1);
+		} else {
+			if (unlikely(sata_dwc_qc_complete(ap, qc, 1)))
+				goto STILLBUSY;
+		}
+		continue;
+
+STILLBUSY:
+		ap->stats.idle_irq++;
+		dev_warn(ap->dev, "STILL BUSY IRQ ata%d: irq trap\n",
+			 ap->print_id);
+	} /* while tag_mask */
+
+	/*
+	 * Check to see if any commands completed while we were processing our
+	 * initial set of completed commands (reading of status clears
+	 * interrupts, so we might miss a completed command interrupt if one
+	 * came in while we were processing --we read status as part of
+	 * processing a completed command).
+	 */
+	sactive2 = core_scr_read(SCR_ACTIVE);
+	if (sactive2 != sactive) {
+		dev_dbg(ap->dev, "More completed-sactive=0x%x sactive2=0x%x\n",
+			sactive, sactive2);
+		goto PROCESS;
+	}
+	handled = 1;
+
+DONE:
+	spin_unlock(&host->lock);
+
+	kfree(hp);
+	return IRQ_RETVAL(handled);
+}
+
+static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag)
+{
+	struct sata_dwc_device *hsdev = HSDEV_FROM_HSDEVP(hsdevp);
+
+	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX) {
+		out_le32(&(hsdev->sata_dwc_regs->dmacr),
+			 SATA_DWC_DMACR_RX_CLEAR(
+				 in_le32(&(hsdev->sata_dwc_regs->dmacr))));
+	} else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX) {
+		out_le32(&(hsdev->sata_dwc_regs->dmacr),
+			 SATA_DWC_DMACR_TX_CLEAR(
+				 in_le32(&(hsdev->sata_dwc_regs->dmacr))));
+	} else {
+		/* This should not happen, it indicates the driver is out of
+		 * sync.  If it does happen, clear dmacr anyway.
+		 */
+		dev_err(host_pvt.dwc_dev, "%s DMA protocol RX and TX DMA not"
+			" pending tag=0x%02x pending=%d dmacr: 0x%08x\n",
+			__func__, tag, hsdevp->dma_pending[tag],
+			in_le32(&(hsdev->sata_dwc_regs->dmacr)));
+		out_le32(&(hsdev->sata_dwc_regs->dmacr),
+			SATA_DWC_DMACR_TXRXCH_CLEAR);
+	}
+}
+
+static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status)
+{
+	struct ata_queued_cmd *qc;
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
+	u8 tag = 0;
+
+	tag = ap->link.active_tag;
+	qc = ata_qc_from_tag(ap, tag);
+
+#ifdef DEBUG_NCQ
+	if (tag > 0) {
+		dev_info(ap->dev, "%s tag=%u cmd=0x%02x dma dir=%s proto=%s "
+			 "dmacr=0x%08x\n", __func__, qc->tag, qc->tf.command,
+			 dir_2_txt(qc->dma_dir), prot_2_txt(qc->tf.protocol),
+			 in_le32(&(hsdev->sata_dwc_regs->dmacr)));
+	}
+#endif
+
+	if (ata_is_dma(qc->tf.protocol)) {
+		if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_NONE) {
+			dev_err(ap->dev, "%s DMA protocol RX and TX DMA not "
+				"pending dmacr: 0x%08x\n", __func__,
+				in_le32(&(hsdev->sata_dwc_regs->dmacr)));
+		}
+
+		hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_NONE;
+		sata_dwc_qc_complete(ap, qc, check_status);
+		ap->link.active_tag = ATA_TAG_POISON;
+	} else {
+		sata_dwc_qc_complete(ap, qc, check_status);
+	}
+}
+
+static int sata_dwc_qc_complete(struct ata_port *ap, struct ata_queued_cmd *qc,
+				u32 check_status)
+{
+	u8 status = 0;
+	int i = 0;
+	u32 mask = 0x0;
+	u8 tag = qc->tag;
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+	u32 serror;
+	struct sata_dwc_host_priv *hp;
+	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+
+	hp->sata_dwc_sactive_issued = 0;
+	hp->sata_dwc_sactive_queued = 0;
+
+	dev_dbg(ap->dev, "%s checkstatus? %x\n", __func__, check_status);
+
+	if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_TX)
+		dev_err(ap->dev, "TX DMA PENDING\n");
+	else if (hsdevp->dma_pending[tag] == SATA_DWC_DMA_PENDING_RX)
+		dev_err(ap->dev, "RX DMA PENDING\n");
+
+	if (check_status) {
+		i = 0;
+		do {
+			/* check main status, clearing INTRQ */
+			status = ap->ops->sff_check_status(ap);
+			if (status & ATA_BUSY) {
+				dev_dbg(ap->dev, "STATUS BUSY (0x%02x) [%d]\n",
+						status, i);
+			}
+			if (++i > 10)
+				break;
+		} while (status & ATA_BUSY);
+
+		status = ap->ops->sff_check_status(ap);
+		if (unlikely(status & ATA_BUSY))
+			dev_err(ap->dev, "QC complete cmd=0x%02x STATUS BUSY"
+				" (0x%02x) [%d]\n", qc->tf.command, status, i);
+		serror = core_scr_read(SCR_ERROR);
+		if (serror & SATA_DWC_SERROR_ERR_BITS)
+			dev_err(ap->dev, "****** SERROR=0x%08x ******\n",
+				serror);
+	}
+	dev_dbg(ap->dev, "QC complete cmd=0x%02x status=0x%02x ata%u:"
+		" protocol=%d\n", qc->tf.command, status, ap->print_id,
+		 qc->tf.protocol);
+
+	/* clear active bit */
+	mask = ~(qcmd_tag_to_mask(tag));
+	hp->sata_dwc_sactive_queued = hp->sata_dwc_sactive_queued & mask;
+	hp->sata_dwc_sactive_issued = hp->sata_dwc_sactive_issued & mask;
+
+	/* Complete taskfile transaction (does not read SCR registers) */
+	ata_qc_complete(qc);
+
+	return 0;
+}
+
+static void sata_dwc_enable_interrupts(struct sata_dwc_device *hsdev)
+{
+	/* Enable selective interrupts by setting the interrupt mask register */
+	out_le32(&hsdev->sata_dwc_regs->intmr,
+		 SATA_DWC_INTMR_ERRM |
+		 SATA_DWC_INTMR_NEWFPM |
+		 SATA_DWC_INTMR_PMABRTM |
+		 SATA_DWC_INTMR_DMATM);
+
+	/* Unmask the error bits that should trigger an error interrupt by
+	 * setting the error mask register.
+	 */
+	out_le32(&hsdev->sata_dwc_regs->errmr, SATA_DWC_SERROR_ERR_BITS);
+
+	dev_dbg(host_pvt.dwc_dev, "%s: INTMR = 0x%08x, ERRMR = 0x%08x\n",
+		__func__, in_le32(&hsdev->sata_dwc_regs->intmr),
+		in_le32(&hsdev->sata_dwc_regs->errmr));
+}
+
+static void sata_dwc_setup_port(struct ata_ioports *port, unsigned long base)
+{
+	port->cmd_addr = (void *)(base + 0x00);
+	port->data_addr = (void *)(base + 0x00);
+
+	port->error_addr = (void *)(base + 0x04);
+	port->feature_addr = (void *)(base + 0x04);
+
+	port->nsect_addr = (void *)(base + 0x08);
+
+	port->lbal_addr = (void *)(base + 0x0c);
+	port->lbam_addr = (void *)(base + 0x10);
+	port->lbah_addr = (void *)(base + 0x14);
+
+	port->device_addr = (void *)(base + 0x18);
+	port->command_addr = (void *)(base + 0x1c);
+	port->status_addr = (void *)(base + 0x1c);
+
+	port->altstatus_addr = (void *)(base + 0x20);
+	port->ctl_addr = (void *)(base + 0x20);
+}
+
+/*
+ * Function : sata_dwc_port_start
+ * arguments : struct ata_ioports *port
+ * Return value : returns 0 if success, error code otherwise
+ * This function allocates the scatter gather LLI table for AHB DMA
+ */
+static int sata_dwc_port_start(struct ata_port *ap)
+{
+	int err = 0;
+	struct sata_dwc_device *hsdev;
+	struct sata_dwc_device_port *hsdevp = NULL;
+	struct device *pdev;
+	u32 sstatus;
+	int i;
+
+	hsdev = HSDEV_FROM_AP(ap);
+
+	dev_dbg(ap->dev, "%s: port_no=%d\n", __func__, ap->port_no);
+
+	hsdev->host = ap->host;
+	pdev = ap->host->dev;
+	if (!pdev) {
+		dev_err(ap->dev, "%s: no ap->host->dev\n", __func__);
+		err = -ENODEV;
+		goto CLEANUP;
+	}
+
+	/* Allocate Port Struct */
+	hsdevp = kmalloc(sizeof(*hsdevp), GFP_KERNEL);
+	if (!hsdevp) {
+		dev_err(ap->dev, "%s: kmalloc failed for hsdevp\n", __func__);
+		err = -ENOMEM;
+		goto CLEANUP;
+	}
+	memset(hsdevp, 0, sizeof(*hsdevp));
+	hsdevp->hsdev = hsdev;
+
+	for (i = 0; i < SATA_DWC_QCMD_MAX; i++)
+		hsdevp->cmd_issued[i] = SATA_DWC_CMD_ISSUED_NOT;
+
+	ap->prd = 0;	/* set these so libata doesn't use them */
+	ap->prd_dma = 0;
+
+	/*
+	 * DMA - Assign scatter gather LLI table. We can't use the libata
+	 * version since it's PRD is IDE PCI specific.
+	 */
+	for (i = 0; i < SATA_DWC_QCMD_MAX; i++) {
+		hsdevp->llit[i] = dma_alloc_coherent(pdev,
+						     SATA_DWC_DMAC_LLI_TBL_SZ,
+						     &(hsdevp->llit_dma[i]),
+						     GFP_ATOMIC);
+		if (!hsdevp->llit[i]) {
+			dev_err(ap->dev, "%s: dma_alloc_coherent failed\n",
+				__func__);
+			err = -ENOMEM;
+			goto CLEANUP;
+		}
+	}
+
+	if (ap->port_no == 0)  {
+		dev_dbg(ap->dev, "%s: clearing TXCHEN, RXCHEN in DMAC\n",
+			__func__);
+		out_le32(&hsdev->sata_dwc_regs->dmacr,
+				 SATA_DWC_DMACR_TXRXCH_CLEAR);
+
+		dev_dbg(ap->dev, "%s:setting burst size in DBTSR\n", __func__);
+		out_le32(&hsdev->sata_dwc_regs->dbtsr,
+			 (SATA_DWC_DBTSR_MWR(AHB_DMA_BRST_DFLT) |
+			  SATA_DWC_DBTSR_MRD(AHB_DMA_BRST_DFLT)));
+	}
+
+	/* Clear any error bits before libata starts issuing commands */
+	clear_serror();
+
+	ap->private_data = hsdevp;
+
+	/* Are we in Gen I or II */
+	sstatus = core_scr_read(SCR_STATUS);
+	switch (SATA_DWC_SCR0_SPD_GET(sstatus)) {
+	case 0x0:
+		dev_info(ap->dev, "**** No negotiated speed (nothing attached?"
+			") ****\n");
+		break;
+	case 0x1:
+		dev_info(ap->dev, "**** GEN I speed rate negotiated ****\n");
+		break;
+	case 0x2:
+		dev_info(ap->dev, "**** GEN II speed rate negotiated ****\n");
+		break;
+	}
+
+CLEANUP:
+	if (err) {
+		kfree(hsdevp);
+		sata_dwc_port_stop(ap);
+		dev_dbg(ap->dev, "%s: fail\n", __func__);
+	} else {
+		dev_dbg(ap->dev, "%s: done\n", __func__);
+	}
+
+	return err;
+}
+
+static void sata_dwc_port_stop(struct ata_port *ap)
+{
+	int i;
+	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+
+	dev_dbg(ap->dev, "%s: ap->id = %d\n", __func__, ap->print_id);
+
+	if (hsdevp && hsdev) {
+		/* deallocate LLI table */
+		for (i = 0; i < SATA_DWC_QCMD_MAX; i++) {
+			dma_free_coherent(ap->host->dev,
+					  SATA_DWC_DMAC_LLI_TBL_SZ,
+					 hsdevp->llit[i], hsdevp->llit_dma[i]);
+		}
+
+		kfree(hsdevp);
+	}
+	ap->private_data = NULL;
+}
+
+/*
+ * Function : sata_dwc_exec_command_by_tag
+ * arguments : ata_port *ap, ata_taskfile *tf, u8 tag, u32 cmd_issued
+ * Return value : None
+ * This function keeps track of individual command tag ids and calls
+ * ata_exec_command in libata
+ */
+static void sata_dwc_exec_command_by_tag(struct ata_port *ap,
+					 struct ata_taskfile *tf,
+					 u8 tag, u32 cmd_issued)
+{
+
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+
+	dev_dbg(ap->dev, "%s cmd(0x%02x): %s tag=%d\n", __func__, tf->command,
+		ata_cmd_2_txt(tf), tag);
+
+	spin_lock(&ap->host->lock);
+	hsdevp->cmd_issued[tag] = cmd_issued;
+	spin_unlock(&ap->host->lock);
+
+	/* Clear SError before executing a new command.
+	 *
+	 * Read a PM's registers now, we will throw away the task
+	 * file values loaded into the shadow registers for this command.
+	 *
+	 * sata_dwc_scr_write and read can not be used here. Clearing the PM
+	 * managed SError register for the disk needs to be done before the
+	 * task file is loaded.
+	 */
+	clear_serror();
+	ata_sff_exec_command(ap, tf);
+}
+
+static void sata_dwc_bmdma_setup_by_tag(struct ata_queued_cmd *qc, u8 tag)
+{
+	sata_dwc_exec_command_by_tag(qc->ap, &qc->tf, tag,
+				     SATA_DWC_CMD_ISSUED_PEND);
+}
+
+static void sata_dwc_bmdma_setup(struct ata_queued_cmd *qc)
+{
+	u8 tag = qc->tag;
+
+	if (ata_is_ncq(qc->tf.protocol)) {
+		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
+			__func__, qc->ap->link.sactive, tag);
+	} else {
+		tag = 0;
+	}
+
+	sata_dwc_bmdma_setup_by_tag(qc, tag);
+}
+
+static void sata_dwc_bmdma_start_by_tag(struct ata_queued_cmd *qc, u8 tag)
+{
+	int start_dma;
+	u32 reg, dma_chan;
+	struct sata_dwc_device *hsdev = HSDEV_FROM_QC(qc);
+	struct ata_port *ap = qc->ap;
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+	int dir = qc->dma_dir;
+	dma_chan = hsdevp->dma_chan[tag];
+
+	/* Used for ata_bmdma_start(qc) -- we are not BMDMA compatible */
+
+	if (hsdevp->cmd_issued[tag] != SATA_DWC_CMD_ISSUED_NOT) {
+		start_dma = 1;
+		if (dir == DMA_TO_DEVICE)
+			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_TX;
+		else
+			hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_RX;
+	} else {
+		dev_err(ap->dev, "%s:Command not pending cmd_issued=%d"
+			" (tag=%d)- DMA NOT started\n", __func__,
+			 hsdevp->cmd_issued[tag], tag);
+		start_dma = 0;
+	}
+
+	dev_dbg(ap->dev, "%s qc=%p tag: %x cmd: 0x%02x dma_dir: %s start_dma?"
+		" %x\n", __func__, qc, tag, qc->tf.command,
+		dir_2_txt(qc->dma_dir), start_dma);
+	sata_dwc_tf_dump(&(qc->tf));
+
+	if (start_dma) {
+		reg = core_scr_read(SCR_ERROR);
+		if (reg & SATA_DWC_SERROR_ERR_BITS) {
+			dev_err(ap->dev, "%s: ****** SError=0x%08x ******\n",
+				__func__, reg);
+		}
+
+		if (dir == DMA_TO_DEVICE)
+			out_le32(&hsdev->sata_dwc_regs->dmacr,
+				SATA_DWC_DMACR_TXCHEN);
+		else
+			out_le32(&hsdev->sata_dwc_regs->dmacr,
+				SATA_DWC_DMACR_RXCHEN);
+
+		/* Enable AHB DMA transfer on the specified channel */
+		dma_dwc_xfer_start(dma_chan);
+	}
+}
+
+static void sata_dwc_bmdma_start(struct ata_queued_cmd *qc)
+{
+	u8 tag = qc->tag;
+
+	if (ata_is_ncq(qc->tf.protocol)) {
+		dev_dbg(qc->ap->dev, "%s: ap->link.sactive=0x%08x tag=%d\n",
+			__func__, qc->ap->link.sactive, tag);
+	} else {
+		tag = 0;
+	}
+
+	dev_dbg(qc->ap->dev, "%s\n", __func__);
+	sata_dwc_bmdma_start_by_tag(qc, tag);
+}
+
+/*
+ * Function : sata_dwc_qc_prep_by_tag
+ * arguments : ata_queued_cmd *qc, u8 tag
+ * Return value : None
+ * qc_prep for a particular queued command based on tag
+ */
+static void sata_dwc_qc_prep_by_tag(struct ata_queued_cmd *qc, u8 tag)
+{
+	struct scatterlist *sg = qc->sg;
+	struct ata_port *ap = qc->ap;
+	u32 dma_chan;
+	struct sata_dwc_device *hsdev = HSDEV_FROM_AP(ap);
+	struct sata_dwc_device_port *hsdevp = HSDEVP_FROM_AP(ap);
+	int err;
+
+	dev_dbg(ap->dev, "%s: port=%d dma dir=%s n_elem=%d\n",
+		__func__, ap->port_no, dir_2_txt(qc->dma_dir), qc->n_elem);
+
+	dma_chan = dma_dwc_xfer_setup(sg, qc->n_elem, hsdevp->llit[tag],
+			hsdevp->llit_dma[tag],
+			(void *__iomem)(&hsdev->sata_dwc_regs->dmadr),
+			qc->dma_dir);
+	if (dma_chan < 0) {
+		dev_err(ap->dev, "%s: dma_dwc_xfer_setup returns err %d\n",
+			__func__, err);
+		return;
+	}
+
+	hsdevp->dma_chan[tag] = dma_chan;
+}
+
+static unsigned int sata_dwc_qc_issue(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+
+#ifdef DEBUG_NCQ
+	if (qc->tag > 0 || ap->link.sactive > 1)
+		dev_info(ap->dev, "%s ap id=%d cmd(0x%02x)=%s qc tag=%d  "
+			 "prot=%s ap active_tag=0x%08x ap sactive=0x%08x\n",
+			 __func__, ap->print_id, qc->tf.command,
+			 ata_cmd_2_txt(&qc->tf), qc->tag,
+			 prot_2_txt(qc->tf.protocol), ap->link.active_tag,
+			 ap->link.sactive);
+#endif
+
+	if (ata_is_ncq(qc->tf.protocol)) {
+		ap->ops->sff_tf_load(ap, &qc->tf);
+		sata_dwc_exec_command_by_tag(ap, &qc->tf, qc->tag,
+					     SATA_DWC_CMD_ISSUED_PEND);
+	} else {
+		ata_sff_qc_issue(qc);
+	}
+
+	return 0;
+}
+
+/*
+ * Function : sata_dwc_qc_prep
+ * arguments : ata_queued_cmd *qc
+ * Return value : None
+ * qc_prep for a particular queued command
+ */
+static void sata_dwc_qc_prep(struct ata_queued_cmd *qc)
+{
+	u32 sactive;
+	u8 tag = qc->tag;
+
+	if ((qc->dma_dir == DMA_NONE) || (qc->tf.protocol == ATA_PROT_PIO))
+		return;
+
+#ifdef DEBUG_NCQ
+	if (qc->tag > 0)
+		dev_info(qc->ap->dev, "%s: qc->tag=%d ap->active_tag=0x%08x\n",
+			 __func__, tag, qc->ap->link.active_tag);
+#endif
+
+	if (ata_is_ncq(qc->tf.protocol)) {
+		sactive = core_scr_read(SCR_ACTIVE);
+		sactive |= (0x00000001 << tag);
+		core_scr_write(SCR_ACTIVE, sactive);
+		dev_dbg(qc->ap->dev, "%s: tag=%d ap->link.sactive = 0x%08x "
+		"sactive=0x%08x\n", __func__, tag, qc->ap->link.sactive,
+		 sactive);
+	} else {
+		tag = 0;
+	}
+
+	sata_dwc_qc_prep_by_tag(qc, tag);
+}
+
+static void sata_dwc_error_handler(struct ata_port *ap)
+{
+	ap->link.flags |= ATA_LFLAG_NO_HRST;
+	ata_sff_error_handler(ap);
+	ap->link.flags &= ~ATA_LFLAG_NO_HRST;
+}
+
+/*
+ * scsi mid-layer and libata interface structures
+ */
+static struct scsi_host_template sata_dwc_sht = {
+	ATA_NCQ_SHT(DRV_NAME),
+	/*
+	 * test-only: Currently this driver doesn't handle NCQ
+	 * correctly. We enable NCQ but set the queue depth to a
+	 * max of 1. This will get fixed in in a future release.
+	 */
+	.sg_tablesize		= LIBATA_MAX_PRD,
+	.can_queue		= ATA_DEF_QUEUE,	/* ATA_MAX_QUEUE */
+	.dma_boundary		= ATA_DMA_BOUNDARY,
+};
+
+static struct ata_port_operations sata_dwc_ops = {
+	.inherits		= &ata_sff_port_ops,
+
+	.error_handler		= sata_dwc_error_handler,
+
+	.qc_prep		= sata_dwc_qc_prep,
+	.qc_issue		= sata_dwc_qc_issue,
+
+	.scr_read		= sata_dwc_scr_read,
+	.scr_write		= sata_dwc_scr_write,
+
+	.port_start		= sata_dwc_port_start,
+	.port_stop		= sata_dwc_port_stop,
+
+	.bmdma_setup		= sata_dwc_bmdma_setup,
+	.bmdma_start		= sata_dwc_bmdma_start,
+};
+
+static const struct ata_port_info sata_dwc_port_info[] = {
+	{
+		.flags		= ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
+				  ATA_FLAG_MMIO | ATA_FLAG_NCQ,
+		.pio_mask	= 0x1f,	/* pio 0-4 */
+		.udma_mask	= ATA_UDMA6,
+		.port_ops	= &sata_dwc_ops,
+	},
+};
+
+static int sata_dwc_probe(struct of_device *ofdev,
+			const struct of_device_id *match)
+{
+	struct sata_dwc_device *hsdev;
+	u32 idr, versionr;
+	char *ver = (char *) &versionr;
+	u8 *base = NULL;
+	int err = 0;
+	int irq;
+	struct ata_host *host;
+	struct ata_port_info pi = sata_dwc_port_info[0];
+	const struct ata_port_info *ppi[] = { &pi, NULL };
+	struct sata_dwc_host_priv *hp;
+	hp = kmalloc(sizeof(*hp), GFP_KERNEL);
+	/* Allocate DWC SATA device */
+	hsdev = kmalloc(sizeof(*hsdev), GFP_KERNEL);
+	if (hsdev == NULL) {
+		dev_err(&ofdev->dev, "kmalloc failed for hsdev\n");
+		err = -ENOMEM;
+		goto error_out;
+	}
+	memset(hsdev, 0, sizeof(*hsdev));
+
+	/* Ioremap SATA registers */
+	base = of_iomap(ofdev->node, 0);
+	if (!base) {
+		dev_err(&ofdev->dev, "ioremap failed for SATA register"
+		" address\n");
+		err = -ENODEV;
+		goto error_out;
+	}
+	hsdev->reg_base = base;
+	dev_dbg(&ofdev->dev, "ioremap done for SATA register address\n");
+
+	/* Synopsys DWC SATA specific Registers */
+	hsdev->sata_dwc_regs = (void *__iomem)(base + SATA_DWC_REG_OFFSET);
+
+	/* Allocate and fill host */
+	host = ata_host_alloc_pinfo(&ofdev->dev, ppi, SATA_DWC_MAX_PORTS);
+	if (!host) {
+		dev_err(&ofdev->dev, "ata_host_alloc_pinfo failed\n");
+		err = -ENOMEM;
+		goto error_out;
+	}
+
+	host->private_data = hsdev;
+
+	/* Setup port */
+	host->ports[0]->ioaddr.cmd_addr = base;
+	host->ports[0]->ioaddr.scr_addr = base + SATA_DWC_SCR_OFFSET;
+	host_pvt.scr_addr_sstatus = base + SATA_DWC_SCR_OFFSET;
+	sata_dwc_setup_port(&host->ports[0]->ioaddr, (unsigned long)base);
+
+	/* Read the ID and Version Registers */
+	idr = in_le32(&hsdev->sata_dwc_regs->idr);
+	versionr = in_le32(&hsdev->sata_dwc_regs->versionr);
+	dev_notice(&ofdev->dev, "id %d, controller version %c.%c%c\n",
+		   idr, ver[0], ver[1], ver[2]);
+
+	/* Get SATA DMA interrupt number */
+	irq = irq_of_parse_and_map(ofdev->node, 1);
+	if (irq == NO_IRQ) {
+		dev_err(&ofdev->dev, "no SATA DMA irq\n");
+		err = -ENODEV;
+		goto error_out;
+	}
+
+	/* Get physical SATA DMA register base address */
+	host_pvt.sata_dma_regs = of_iomap(ofdev->node, 1);
+	if (!host_pvt.sata_dma_regs) {
+		dev_err(&ofdev->dev, "ioremap failed for AHBDMA register"
+		" address\n");
+		err = -ENODEV;
+		goto error_out;
+	}
+
+	/* Save dev for later use in dev_xxx() routines */
+	host_pvt.dwc_dev = &ofdev->dev;
+
+	/* Initialize AHB DMAC */
+	dma_dwc_init(hsdev, irq);
+
+	/* Enable SATA Interrupts */
+	sata_dwc_enable_interrupts(hsdev);
+
+	/* Get SATA interrupt number */
+	irq = irq_of_parse_and_map(ofdev->node, 0);
+	if (irq == NO_IRQ) {
+		dev_err(&ofdev->dev, "no SATA DMA irq\n");
+		err = -ENODEV;
+		goto error_out;
+	}
+
+	/*
+	 * Now, register with libATA core, this will also initiate the
+	 * device discovery process, invoking our port_start() handler &
+	 * error_handler() to execute a dummy Softreset EH session
+	 */
+	ata_host_activate(host, irq, sata_dwc_isr, 0, &sata_dwc_sht);
+
+	dev_set_drvdata(&ofdev->dev, host);
+
+	/* Everything is fine */
+	return 0;
+
+error_out:
+	/* Free SATA DMA resources */
+	dma_dwc_exit(hsdev);
+
+	if (base)
+		iounmap(base);
+
+	kfree(hsdev);
+
+	return err;
+}
+
+static int sata_dwc_remove(struct of_device *ofdev)
+{
+	struct device *dev = &ofdev->dev;
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct sata_dwc_device *hsdev = host->private_data;
+
+	ata_host_detach(host);
+
+	dev_set_drvdata(dev, NULL);
+
+	/* Free SATA DMA resources */
+	dma_dwc_exit(hsdev);
+
+	iounmap(hsdev->reg_base);
+	kfree(hsdev);
+	kfree(host);
+
+	dev_dbg(&ofdev->dev, "done\n");
+
+	return 0;
+}
+
+static const struct of_device_id sata_dwc_match[] = {
+	{ .compatible = "amcc,sata-460ex", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sata_dwc_match);
+
+static struct of_platform_driver sata_dwc_driver = {
+	.name = "sata-dwc",
+	.match_table = sata_dwc_match,
+	.probe = sata_dwc_probe,
+	.remove = sata_dwc_remove,
+};
+
+static int __init sata_dwc_init(void)
+{
+	return of_register_platform_driver(&sata_dwc_driver);
+}
+
+static void __exit sata_dwc_exit(void)
+{
+	of_unregister_platform_driver(&sata_dwc_driver);
+}
+
+module_init(sata_dwc_init);
+module_exit(sata_dwc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Miesfeld <mmiesfeld@appliedmicro.com>");
+MODULE_DESCRIPTION("DesignWare Cores SATA controller low lever driver");
+MODULE_VERSION(DRV_VERSION);