libata-core.c

linux 内核源代码

}

/**
 *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
 *	@xfer_mode: XFER_* of interest
 *
 *	Return matching xfer_mask for @xfer_mode.
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	Matching xfer_mask, 0 if no match found.
 */
static unsigned int ata_xfer_mode2mask(u8 xfer_mode)
{
	const struct ata_xfer_ent *ent;

	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
			return 1 << (ent->shift + xfer_mode - ent->base);
	return 0;
}

/**
 *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
 *	@xfer_mode: XFER_* of interest
 *
 *	Return matching xfer_shift for @xfer_mode.
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	Matching xfer_shift, -1 if no match found.
 */
static int ata_xfer_mode2shift(unsigned int xfer_mode)
{
	const struct ata_xfer_ent *ent;

	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
			return ent->shift;
	return -1;
}

/**
 *	ata_mode_string - convert xfer_mask to string
 *	@xfer_mask: mask of bits supported; only highest bit counts.
 *
 *	Determine string which represents the highest speed
 *	(highest bit in @modemask).
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	Constant C string representing highest speed listed in
 *	@mode_mask, or the constant C string "<n/a>".
 */
static const char *ata_mode_string(unsigned int xfer_mask)
{
	static const char * const xfer_mode_str[] = {
		"PIO0",
		"PIO1",
		"PIO2",
		"PIO3",
		"PIO4",
		"PIO5",
		"PIO6",
		"MWDMA0",
		"MWDMA1",
		"MWDMA2",
		"MWDMA3",
		"MWDMA4",
		"UDMA/16",
		"UDMA/25",
		"UDMA/33",
		"UDMA/44",
		"UDMA/66",
		"UDMA/100",
		"UDMA/133",
		"UDMA7",
	};
	int highbit;

	highbit = fls(xfer_mask) - 1;
	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
		return xfer_mode_str[highbit];
	return "<n/a>";
}

static const char *sata_spd_string(unsigned int spd)
{
	static const char * const spd_str[] = {
		"1.5 Gbps",
		"3.0 Gbps",
	};

	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
		return "<unknown>";
	return spd_str[spd - 1];
}

void ata_dev_disable(struct ata_device *dev)
{
	if (ata_dev_enabled(dev)) {
		if (ata_msg_drv(dev->link->ap))
			ata_dev_printk(dev, KERN_WARNING, "disabled\n");
		ata_acpi_on_disable(dev);
		ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 |
					     ATA_DNXFER_QUIET);
		dev->class++;
	}
}

static int ata_dev_set_dipm(struct ata_device *dev, enum link_pm policy)
{
	struct ata_link *link = dev->link;
	struct ata_port *ap = link->ap;
	u32 scontrol;
	unsigned int err_mask;
	int rc;

	/*
	 * disallow DIPM for drivers which haven't set
	 * ATA_FLAG_IPM.  This is because when DIPM is enabled,
	 * phy ready will be set in the interrupt status on
	 * state changes, which will cause some drivers to
	 * think there are errors - additionally drivers will
	 * need to disable hot plug.
	 */
	if (!(ap->flags & ATA_FLAG_IPM) || !ata_dev_enabled(dev)) {
		ap->pm_policy = NOT_AVAILABLE;
		return -EINVAL;
	}

	/*
	 * For DIPM, we will only enable it for the
	 * min_power setting.
	 *
	 * Why?  Because Disks are too stupid to know that
	 * If the host rejects a request to go to SLUMBER
	 * they should retry at PARTIAL, and instead it
	 * just would give up.  So, for medium_power to
	 * work at all, we need to only allow HIPM.
	 */
	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
	if (rc)
		return rc;

	switch (policy) {
	case MIN_POWER:
		/* no restrictions on IPM transitions */
		scontrol &= ~(0x3 << 8);
		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
		if (rc)
			return rc;

		/* enable DIPM */
		if (dev->flags & ATA_DFLAG_DIPM)
			err_mask = ata_dev_set_feature(dev,
					SETFEATURES_SATA_ENABLE, SATA_DIPM);
		break;
	case MEDIUM_POWER:
		/* allow IPM to PARTIAL */
		scontrol &= ~(0x1 << 8);
		scontrol |= (0x2 << 8);
		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
		if (rc)
			return rc;

		/*
		 * we don't have to disable DIPM since IPM flags
		 * disallow transitions to SLUMBER, which effectively
		 * disable DIPM if it does not support PARTIAL
		 */
		break;
	case NOT_AVAILABLE:
	case MAX_PERFORMANCE:
		/* disable all IPM transitions */
		scontrol |= (0x3 << 8);
		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
		if (rc)
			return rc;

		/*
		 * we don't have to disable DIPM since IPM flags
		 * disallow all transitions which effectively
		 * disable DIPM anyway.
		 */
		break;
	}

	/* FIXME: handle SET FEATURES failure */
	(void) err_mask;

	return 0;
}

/**
 *	ata_dev_enable_pm - enable SATA interface power management
 *	@dev:  device to enable power management
 *	@policy: the link power management policy
 *
 *	Enable SATA Interface power management.  This will enable
 *	Device Interface Power Management (DIPM) for min_power
 * 	policy, and then call driver specific callbacks for
 *	enabling Host Initiated Power management.
 *
 *	Locking: Caller.
 *	Returns: -EINVAL if IPM is not supported, 0 otherwise.
 */
void ata_dev_enable_pm(struct ata_device *dev, enum link_pm policy)
{
	int rc = 0;
	struct ata_port *ap = dev->link->ap;

	/* set HIPM first, then DIPM */
	if (ap->ops->enable_pm)
		rc = ap->ops->enable_pm(ap, policy);
	if (rc)
		goto enable_pm_out;
	rc = ata_dev_set_dipm(dev, policy);

enable_pm_out:
	if (rc)
		ap->pm_policy = MAX_PERFORMANCE;
	else
		ap->pm_policy = policy;
	return /* rc */;	/* hopefully we can use 'rc' eventually */
}

#ifdef CONFIG_PM
/**
 *	ata_dev_disable_pm - disable SATA interface power management
 *	@dev: device to disable power management
 *
 *	Disable SATA Interface power management.  This will disable
 *	Device Interface Power Management (DIPM) without changing
 * 	policy,  call driver specific callbacks for disabling Host
 * 	Initiated Power management.
 *
 *	Locking: Caller.
 *	Returns: void
 */
static void ata_dev_disable_pm(struct ata_device *dev)
{
	struct ata_port *ap = dev->link->ap;

	ata_dev_set_dipm(dev, MAX_PERFORMANCE);
	if (ap->ops->disable_pm)
		ap->ops->disable_pm(ap);
}
#endif	/* CONFIG_PM */

void ata_lpm_schedule(struct ata_port *ap, enum link_pm policy)
{
	ap->pm_policy = policy;
	ap->link.eh_info.action |= ATA_EHI_LPM;
	ap->link.eh_info.flags |= ATA_EHI_NO_AUTOPSY;
	ata_port_schedule_eh(ap);
}

#ifdef CONFIG_PM
static void ata_lpm_enable(struct ata_host *host)
{
	struct ata_link *link;
	struct ata_port *ap;
	struct ata_device *dev;
	int i;

	for (i = 0; i < host->n_ports; i++) {
		ap = host->ports[i];
		ata_port_for_each_link(link, ap) {
			ata_link_for_each_dev(dev, link)
				ata_dev_disable_pm(dev);
		}
	}
}

static void ata_lpm_disable(struct ata_host *host)
{
	int i;

	for (i = 0; i < host->n_ports; i++) {
		struct ata_port *ap = host->ports[i];
		ata_lpm_schedule(ap, ap->pm_policy);
	}
}
#endif	/* CONFIG_PM */


/**
 *	ata_devchk - PATA device presence detection
 *	@ap: ATA channel to examine
 *	@device: Device to examine (starting at zero)
 *
 *	This technique was originally described in
 *	Hale Landis's ATADRVR (www.ata-atapi.com), and
 *	later found its way into the ATA/ATAPI spec.
 *
 *	Write a pattern to the ATA shadow registers,
 *	and if a device is present, it will respond by
 *	correctly storing and echoing back the
 *	ATA shadow register contents.
 *
 *	LOCKING:
 *	caller.
 */

static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
{
	struct ata_ioports *ioaddr = &ap->ioaddr;
	u8 nsect, lbal;

	ap->ops->dev_select(ap, device);

	iowrite8(0x55, ioaddr->nsect_addr);
	iowrite8(0xaa, ioaddr->lbal_addr);

	iowrite8(0xaa, ioaddr->nsect_addr);
	iowrite8(0x55, ioaddr->lbal_addr);

	iowrite8(0x55, ioaddr->nsect_addr);
	iowrite8(0xaa, ioaddr->lbal_addr);

	nsect = ioread8(ioaddr->nsect_addr);
	lbal = ioread8(ioaddr->lbal_addr);

	if ((nsect == 0x55) && (lbal == 0xaa))
		return 1;	/* we found a device */

	return 0;		/* nothing found */
}

/**
 *	ata_dev_classify - determine device type based on ATA-spec signature
 *	@tf: ATA taskfile register set for device to be identified
 *
 *	Determine from taskfile register contents whether a device is
 *	ATA or ATAPI, as per "Signature and persistence" section
 *	of ATA/PI spec (volume 1, sect 5.14).
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP or
 *	%ATA_DEV_UNKNOWN the event of failure.
 */
unsigned int ata_dev_classify(const struct ata_taskfile *tf)
{
	/* Apple's open source Darwin code hints that some devices only
	 * put a proper signature into the LBA mid/high registers,
	 * So, we only check those.  It's sufficient for uniqueness.
	 *
	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
	 * signatures for ATA and ATAPI devices attached on SerialATA,
	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
	 * spec has never mentioned about using different signatures
	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
	 * Multiplier specification began to use 0x69/0x96 to identify
	 * port multpliers and 0x3c/0xc3 to identify SEMB device.
	 * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
	 * 0x69/0x96 shortly and described them as reserved for
	 * SerialATA.
	 *
	 * We follow the current spec and consider that 0x69/0x96
	 * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
	 */
	if ((tf->lbam == 0) && (tf->lbah == 0)) {
		DPRINTK("found ATA device by sig\n");
		return ATA_DEV_ATA;
	}

	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
		DPRINTK("found ATAPI device by sig\n");
		return ATA_DEV_ATAPI;
	}

	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
		DPRINTK("found PMP device by sig\n");
		return ATA_DEV_PMP;
	}

	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
		printk(KERN_INFO "ata: SEMB device ignored\n");
		return ATA_DEV_SEMB_UNSUP; /* not yet */
	}

	DPRINTK("unknown device\n");
	return ATA_DEV_UNKNOWN;
}

/**
 *	ata_dev_try_classify - Parse returned ATA device signature
 *	@dev: ATA device to classify (starting at zero)
 *	@present: device seems present
 *	@r_err: Value of error register on completion
 *
 *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
 *	an ATA/ATAPI-defined set of values is placed in the ATA
 *	shadow registers, indicating the results of device detection
 *	and diagnostics.
 *
 *	Select the ATA device, and read the values from the ATA shadow
 *	registers.  Then parse according to the Error register value,
 *	and the spec-defined values examined by ata_dev_classify().
 *
 *	LOCKING:
 *	caller.
 *
 *	RETURNS:
 *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
 */
unsigned int ata_dev_try_classify(struct ata_device *dev, int present,
				  u8 *r_err)
{
	struct ata_port *ap = dev->link->ap;
	struct ata_taskfile tf;
	unsigned int class;
	u8 err;

	ap->ops->dev_select(ap, dev->devno);

	memset(&tf, 0, sizeof(tf));

	ap->ops->tf_read(ap, &tf);
	err = tf.feature;
	if (r_err)
		*r_err = err;

	/* see if device passed diags: if master then continue and warn later */
	if (err == 0 && dev->devno == 0)
		/* diagnostic fail : do nothing _YET_ */
		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
	else if (err == 1)
		/* do nothing */ ;
	else if ((dev->devno == 0) && (err == 0x81))
		/* do nothing */ ;
	else
		return ATA_DEV_NONE;

	/* determine if device is ATA or ATAPI */
	class = ata_dev_classify(&tf);

	if (class == ATA_DEV_UNKNOWN) {
		/* If the device failed diagnostic, it's likely to
		 * have reported incorrect device signature too.
		 * Assume ATA device if the device seems present but
		 * device signature is invalid with diagnostic
		 * failure.
		 */
		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
			class = ATA_DEV_ATA;
		else
			class = ATA_DEV_NONE;
	} else if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
		class = ATA_DEV_NONE;

	return class;
}

/**
 *	ata_id_string - Convert IDENTIFY DEVICE page into string
 *	@id: IDENTIFY DEVICE results we will examine
 *	@s: string into which data is output
 *	@ofs: offset into identify device page
 *	@len: length of string to return. must be an even number.
 *
 *	The strings in the IDENTIFY DEVICE page are broken up into
 *	16-bit chunks.  Run through the string, and output each
 *	8-bit chunk linearly, regardless of platform.
 *
 *	LOCKING:
 *	caller.
 */

void ata_id_string(const u16 *id, unsigned char *s,
		   unsigned int ofs, unsigned int len)
{
	unsigned int c;

	while (len > 0) {
		c = id[ofs] >> 8;
		*s = c;
		s++;

		c = id[ofs] & 0xff;
		*s = c;
		s++;

		ofs++;
		len -= 2;
	}
}

/**
 *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
 *	@id: IDENTIFY DEVICE results we will examine
 *	@s: string into which data is output
 *	@ofs: offset into identify device page
 *	@len: length of string to return. must be an odd number.
 *
 *	This function is identical to ata_id_string except that it
 *	trims trailing spaces and terminates the resulting string with
 *	null.  @len must be actual maximum length (even number) + 1.
 *
 *	LOCKING:
 *	caller.
 */
void ata_id_c_string(const u16 *id, unsigned char *s,
		     unsigned int ofs, unsigned int len)
{
	unsigned char *p;