Commit a6d5a51c authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
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[PATCH] libata: reimplement ata_set_mode() using xfer_mask helpers 



Use xfer_mask helpers to determine transfer mode.  This rewrite also
makes transfer mode determination done before any actual
configuration.  This patch doesn't result in any functional changes.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 23e71c3d

drivers/scsi/libata-core.c

+79 −154
Original line number Diff line number Diff line
@@ -65,11 +65,9 @@ static unsigned int ata_dev_init_params(struct ata_port *ap, 
					struct ata_device *dev);

static void ata_set_mode(struct ata_port *ap);

static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev);

static unsigned int ata_get_mode_mask(const struct ata_port *ap, int shift);

static unsigned int ata_dev_xfermask(struct ata_port *ap,

				     struct ata_device *dev);

static int fgb(u32 bitmap);

static int ata_choose_xfer_mode(const struct ata_port *ap,

				u8 *xfer_mode_out,

				unsigned int *xfer_shift_out);



static unsigned int ata_unique_id = 1;

static struct workqueue_struct *ata_wq;
@@ -1776,53 +1774,44 @@ static void ata_dev_set_mode(struct ata_port *ap, struct ata_device *dev) 


static int ata_host_set_pio(struct ata_port *ap)

{

	unsigned int mask;

	int x, i;

	u8 base, xfer_mode;

	int i;



	for (i = 0; i < ATA_MAX_DEVICES; i++) {

		struct ata_device *dev = &ap->device[i];



	mask = ata_get_mode_mask(ap, ATA_SHIFT_PIO);

	x = fgb(mask);

	if (x < 0) {

		if (!ata_dev_present(dev))

			continue;



		if (!dev->pio_mode) {

			printk(KERN_WARNING "ata%u: no PIO support\n", ap->id);

			return -1;

		}



	base = base_from_shift(ATA_SHIFT_PIO);

	xfer_mode = base + x;



	DPRINTK("base 0x%x xfer_mode 0x%x mask 0x%x x %d\n",

		(int)base, (int)xfer_mode, mask, x);



	for (i = 0; i < ATA_MAX_DEVICES; i++) {

		struct ata_device *dev = &ap->device[i];

		if (ata_dev_present(dev)) {

			dev->pio_mode = xfer_mode;

			dev->xfer_mode = xfer_mode;

		dev->xfer_mode = dev->pio_mode;

		dev->xfer_shift = ATA_SHIFT_PIO;

		if (ap->ops->set_piomode)

			ap->ops->set_piomode(ap, dev);

	}

	}



	return 0;

}



static void ata_host_set_dma(struct ata_port *ap, u8 xfer_mode,

			    unsigned int xfer_shift)

static void ata_host_set_dma(struct ata_port *ap)

{

	int i;



	for (i = 0; i < ATA_MAX_DEVICES; i++) {

		struct ata_device *dev = &ap->device[i];

		if (ata_dev_present(dev)) {

			dev->dma_mode = xfer_mode;

			dev->xfer_mode = xfer_mode;

			dev->xfer_shift = xfer_shift;



		if (!ata_dev_present(dev) || !dev->dma_mode)

			continue;



		dev->xfer_mode = dev->dma_mode;

		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);

		if (ap->ops->set_dmamode)

			ap->ops->set_dmamode(ap, dev);

	}

}

}



/**

 *	ata_set_mode - Program timings and issue SET FEATURES - XFER
@@ -1835,28 +1824,34 @@ static void ata_host_set_dma(struct ata_port *ap, u8 xfer_mode, 
 */

static void ata_set_mode(struct ata_port *ap)

{

	unsigned int xfer_shift;

	u8 xfer_mode;

	int rc;

	int i, rc;



	/* step 1: always set host PIO timings */

	rc = ata_host_set_pio(ap);

	if (rc)

		goto err_out;

	/* step 1: calculate xfer_mask */

	for (i = 0; i < ATA_MAX_DEVICES; i++) {

		struct ata_device *dev = &ap->device[i];

		unsigned int xfer_mask;



	/* step 2: choose the best data xfer mode */

	xfer_mode = xfer_shift = 0;

	rc = ata_choose_xfer_mode(ap, &xfer_mode, &xfer_shift);

		if (!ata_dev_present(dev))

			continue;



		xfer_mask = ata_dev_xfermask(ap, dev);



		dev->pio_mode = ata_xfer_mask2mode(xfer_mask & ATA_MASK_PIO);

		dev->dma_mode = ata_xfer_mask2mode(xfer_mask & (ATA_MASK_MWDMA |

								ATA_MASK_UDMA));

	}



	/* step 2: always set host PIO timings */

	rc = ata_host_set_pio(ap);

	if (rc)

		goto err_out;



	/* step 3: if that xfer mode isn't PIO, set host DMA timings */

	if (xfer_shift != ATA_SHIFT_PIO)

		ata_host_set_dma(ap, xfer_mode, xfer_shift);

	/* step 3: set host DMA timings */

	ata_host_set_dma(ap);



	/* step 4: update devices' xfer mode */

	ata_dev_set_mode(ap, &ap->device[0]);

	ata_dev_set_mode(ap, &ap->device[1]);

	for (i = 0; i < ATA_MAX_DEVICES; i++)

		ata_dev_set_mode(ap, &ap->device[i]);



	if (ap->flags & ATA_FLAG_PORT_DISABLED)

		return;
@@ -2654,77 +2649,45 @@ static int ata_dma_blacklisted(const struct ata_device *dev) 
	return 0;

}



static unsigned int ata_get_mode_mask(const struct ata_port *ap, int shift)

/**

 *	ata_dev_xfermask - Compute supported xfermask of the given device

 *	@ap: Port on which the device to compute xfermask for resides

 *	@dev: Device to compute xfermask for

 *

 *	Compute supported xfermask of @dev.  This function is

 *	responsible for applying all known limits including host

 *	controller limits, device blacklist, etc...

 *

 *	LOCKING:

 *	None.

 *

 *	RETURNS:

 *	Computed xfermask.

 */

static unsigned int ata_dev_xfermask(struct ata_port *ap,

				     struct ata_device *dev)

{

	const struct ata_device *master, *slave;

	unsigned int mask;



	master = &ap->device[0];

	slave = &ap->device[1];

	unsigned long xfer_mask;

	int i;



	WARN_ON(!ata_dev_present(master) && !ata_dev_present(slave));

	xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,

				      ap->udma_mask);



	if (shift == ATA_SHIFT_UDMA) {

		mask = ap->udma_mask;

		if (ata_dev_present(master)) {

			mask &= (master->id[ATA_ID_UDMA_MODES] & 0xff);

			if (ata_dma_blacklisted(master)) {

				mask = 0;

				ata_pr_blacklisted(ap, master);

			}

		}

		if (ata_dev_present(slave)) {

			mask &= (slave->id[ATA_ID_UDMA_MODES] & 0xff);

			if (ata_dma_blacklisted(slave)) {

				mask = 0;

				ata_pr_blacklisted(ap, slave);

			}

		}

	}

	else if (shift == ATA_SHIFT_MWDMA) {

		mask = ap->mwdma_mask;

		if (ata_dev_present(master)) {

			mask &= (master->id[ATA_ID_MWDMA_MODES] & 0x07);

			if (ata_dma_blacklisted(master)) {

				mask = 0;

				ata_pr_blacklisted(ap, master);

			}

		}

		if (ata_dev_present(slave)) {

			mask &= (slave->id[ATA_ID_MWDMA_MODES] & 0x07);

			if (ata_dma_blacklisted(slave)) {

				mask = 0;

				ata_pr_blacklisted(ap, slave);

			}

		}

	}

	else if (shift == ATA_SHIFT_PIO) {

		mask = ap->pio_mask;

		if (ata_dev_present(master)) {

			/* spec doesn't return explicit support for

			 * PIO0-2, so we fake it

			 */

			u16 tmp_mode = master->id[ATA_ID_PIO_MODES] & 0x03;

			tmp_mode <<= 3;

			tmp_mode |= 0x7;

			mask &= tmp_mode;

		}

		if (ata_dev_present(slave)) {

			/* spec doesn't return explicit support for

			 * PIO0-2, so we fake it

			 */

			u16 tmp_mode = slave->id[ATA_ID_PIO_MODES] & 0x03;

			tmp_mode <<= 3;

			tmp_mode |= 0x7;

			mask &= tmp_mode;

		}

	}

	else {

		mask = 0xffffffff; /* shut up compiler warning */

		BUG();

	/* use port-wide xfermask for now */

	for (i = 0; i < ATA_MAX_DEVICES; i++) {

		struct ata_device *d = &ap->device[i];

		if (!ata_dev_present(d))

			continue;

		xfer_mask &= ata_id_xfermask(d->id);

		if (ata_dma_blacklisted(d))

			xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);

	}



	return mask;

	if (ata_dma_blacklisted(dev))

		printk(KERN_WARNING "ata%u: dev %u is on DMA blacklist, "

		       "disabling DMA\n", ap->id, dev->devno);



	return xfer_mask;

}



/* find greatest bit */
@@ -2740,44 +2703,6 @@ static int fgb(u32 bitmap) 
	return x;

}



/**

 *	ata_choose_xfer_mode - attempt to find best transfer mode

 *	@ap: Port for which an xfer mode will be selected

 *	@xfer_mode_out: (output) SET FEATURES - XFER MODE code

 *	@xfer_shift_out: (output) bit shift that selects this mode

 *

 *	Based on host and device capabilities, determine the

 *	maximum transfer mode that is amenable to all.

 *

 *	LOCKING:

 *	PCI/etc. bus probe sem.

 *

 *	RETURNS:

 *	Zero on success, negative on error.

 */



static int ata_choose_xfer_mode(const struct ata_port *ap,

				u8 *xfer_mode_out,

				unsigned int *xfer_shift_out)

{

	unsigned int mask, shift;

	int x, i;



	for (i = 0; i < ARRAY_SIZE(xfer_mode_classes); i++) {

		shift = xfer_mode_classes[i].shift;

		mask = ata_get_mode_mask(ap, shift);



		x = fgb(mask);

		if (x >= 0) {

			*xfer_mode_out = xfer_mode_classes[i].base + x;

			*xfer_shift_out = shift;

			return 0;

		}

	}



	return -1;

}



/**

 *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command

 *	@ap: Port associated with device @dev