libata-core.c

linux 内核源代码

/**
 *	ata_port_flush_task - Flush port_task
 *	@ap: The ata_port to flush port_task for
 *
 *	After this function completes, port_task is guranteed not to
 *	be running or scheduled.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep)
 */
void ata_port_flush_task(struct ata_port *ap)
{
	DPRINTK("ENTER\n");

	cancel_rearming_delayed_work(&ap->port_task);

	if (ata_msg_ctl(ap))
		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __FUNCTION__);
}

static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
{
	struct completion *waiting = qc->private_data;

	complete(waiting);
}

/**
 *	ata_exec_internal_sg - execute libata internal command
 *	@dev: Device to which the command is sent
 *	@tf: Taskfile registers for the command and the result
 *	@cdb: CDB for packet command
 *	@dma_dir: Data tranfer direction of the command
 *	@sgl: sg list for the data buffer of the command
 *	@n_elem: Number of sg entries
 *	@timeout: Timeout in msecs (0 for default)
 *
 *	Executes libata internal command with timeout.  @tf contains
 *	command on entry and result on return.  Timeout and error
 *	conditions are reported via return value.  No recovery action
 *	is taken after a command times out.  It's caller's duty to
 *	clean up after timeout.
 *
 *	LOCKING:
 *	None.  Should be called with kernel context, might sleep.
 *
 *	RETURNS:
 *	Zero on success, AC_ERR_* mask on failure
 */
unsigned ata_exec_internal_sg(struct ata_device *dev,
			      struct ata_taskfile *tf, const u8 *cdb,
			      int dma_dir, struct scatterlist *sgl,
			      unsigned int n_elem, unsigned long timeout)
{
	struct ata_link *link = dev->link;
	struct ata_port *ap = link->ap;
	u8 command = tf->command;
	struct ata_queued_cmd *qc;
	unsigned int tag, preempted_tag;
	u32 preempted_sactive, preempted_qc_active;
	int preempted_nr_active_links;
	DECLARE_COMPLETION_ONSTACK(wait);
	unsigned long flags;
	unsigned int err_mask;
	int rc;

	spin_lock_irqsave(ap->lock, flags);

	/* no internal command while frozen */
	if (ap->pflags & ATA_PFLAG_FROZEN) {
		spin_unlock_irqrestore(ap->lock, flags);
		return AC_ERR_SYSTEM;
	}

	/* initialize internal qc */

	/* XXX: Tag 0 is used for drivers with legacy EH as some
	 * drivers choke if any other tag is given.  This breaks
	 * ata_tag_internal() test for those drivers.  Don't use new
	 * EH stuff without converting to it.
	 */
	if (ap->ops->error_handler)
		tag = ATA_TAG_INTERNAL;
	else
		tag = 0;

	if (test_and_set_bit(tag, &ap->qc_allocated))
		BUG();
	qc = __ata_qc_from_tag(ap, tag);

	qc->tag = tag;
	qc->scsicmd = NULL;
	qc->ap = ap;
	qc->dev = dev;
	ata_qc_reinit(qc);

	preempted_tag = link->active_tag;
	preempted_sactive = link->sactive;
	preempted_qc_active = ap->qc_active;
	preempted_nr_active_links = ap->nr_active_links;
	link->active_tag = ATA_TAG_POISON;
	link->sactive = 0;
	ap->qc_active = 0;
	ap->nr_active_links = 0;

	/* prepare & issue qc */
	qc->tf = *tf;
	if (cdb)
		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
	qc->flags |= ATA_QCFLAG_RESULT_TF;
	qc->dma_dir = dma_dir;
	if (dma_dir != DMA_NONE) {
		unsigned int i, buflen = 0;
		struct scatterlist *sg;

		for_each_sg(sgl, sg, n_elem, i)
			buflen += sg->length;

		ata_sg_init(qc, sgl, n_elem);
		qc->nbytes = buflen;
	}

	qc->private_data = &wait;
	qc->complete_fn = ata_qc_complete_internal;

	ata_qc_issue(qc);

	spin_unlock_irqrestore(ap->lock, flags);

	if (!timeout)
		timeout = ata_probe_timeout * 1000 / HZ;

	rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));

	ata_port_flush_task(ap);

	if (!rc) {
		spin_lock_irqsave(ap->lock, flags);

		/* We're racing with irq here.  If we lose, the
		 * following test prevents us from completing the qc
		 * twice.  If we win, the port is frozen and will be
		 * cleaned up by ->post_internal_cmd().
		 */
		if (qc->flags & ATA_QCFLAG_ACTIVE) {
			qc->err_mask |= AC_ERR_TIMEOUT;

			if (ap->ops->error_handler)
				ata_port_freeze(ap);
			else
				ata_qc_complete(qc);

			if (ata_msg_warn(ap))
				ata_dev_printk(dev, KERN_WARNING,
					"qc timeout (cmd 0x%x)\n", command);
		}

		spin_unlock_irqrestore(ap->lock, flags);
	}

	/* do post_internal_cmd */
	if (ap->ops->post_internal_cmd)
		ap->ops->post_internal_cmd(qc);

	/* perform minimal error analysis */
	if (qc->flags & ATA_QCFLAG_FAILED) {
		if (qc->result_tf.command & (ATA_ERR | ATA_DF))
			qc->err_mask |= AC_ERR_DEV;

		if (!qc->err_mask)
			qc->err_mask |= AC_ERR_OTHER;

		if (qc->err_mask & ~AC_ERR_OTHER)
			qc->err_mask &= ~AC_ERR_OTHER;
	}

	/* finish up */
	spin_lock_irqsave(ap->lock, flags);

	*tf = qc->result_tf;
	err_mask = qc->err_mask;

	ata_qc_free(qc);
	link->active_tag = preempted_tag;
	link->sactive = preempted_sactive;
	ap->qc_active = preempted_qc_active;
	ap->nr_active_links = preempted_nr_active_links;

	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
	 * Until those drivers are fixed, we detect the condition
	 * here, fail the command with AC_ERR_SYSTEM and reenable the
	 * port.
	 *
	 * Note that this doesn't change any behavior as internal
	 * command failure results in disabling the device in the
	 * higher layer for LLDDs without new reset/EH callbacks.
	 *
	 * Kill the following code as soon as those drivers are fixed.
	 */
	if (ap->flags & ATA_FLAG_DISABLED) {
		err_mask |= AC_ERR_SYSTEM;
		ata_port_probe(ap);
	}

	spin_unlock_irqrestore(ap->lock, flags);

	return err_mask;
}

/**
 *	ata_exec_internal - execute libata internal command
 *	@dev: Device to which the command is sent
 *	@tf: Taskfile registers for the command and the result
 *	@cdb: CDB for packet command
 *	@dma_dir: Data tranfer direction of the command
 *	@buf: Data buffer of the command
 *	@buflen: Length of data buffer
 *	@timeout: Timeout in msecs (0 for default)
 *
 *	Wrapper around ata_exec_internal_sg() which takes simple
 *	buffer instead of sg list.
 *
 *	LOCKING:
 *	None.  Should be called with kernel context, might sleep.
 *
 *	RETURNS:
 *	Zero on success, AC_ERR_* mask on failure
 */
unsigned ata_exec_internal(struct ata_device *dev,
			   struct ata_taskfile *tf, const u8 *cdb,
			   int dma_dir, void *buf, unsigned int buflen,
			   unsigned long timeout)
{
	struct scatterlist *psg = NULL, sg;
	unsigned int n_elem = 0;

	if (dma_dir != DMA_NONE) {
		WARN_ON(!buf);
		sg_init_one(&sg, buf, buflen);
		psg = &sg;
		n_elem++;
	}

	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
				    timeout);
}

/**
 *	ata_do_simple_cmd - execute simple internal command
 *	@dev: Device to which the command is sent
 *	@cmd: Opcode to execute
 *
 *	Execute a 'simple' command, that only consists of the opcode
 *	'cmd' itself, without filling any other registers
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	Zero on success, AC_ERR_* mask on failure
 */
unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
{
	struct ata_taskfile tf;

	ata_tf_init(dev, &tf);

	tf.command = cmd;
	tf.flags |= ATA_TFLAG_DEVICE;
	tf.protocol = ATA_PROT_NODATA;

	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
}

/**
 *	ata_pio_need_iordy	-	check if iordy needed
 *	@adev: ATA device
 *
 *	Check if the current speed of the device requires IORDY. Used
 *	by various controllers for chip configuration.
 */

unsigned int ata_pio_need_iordy(const struct ata_device *adev)
{
	/* Controller doesn't support  IORDY. Probably a pointless check
	   as the caller should know this */
	if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
		return 0;
	/* PIO3 and higher it is mandatory */
	if (adev->pio_mode > XFER_PIO_2)
		return 1;
	/* We turn it on when possible */
	if (ata_id_has_iordy(adev->id))
		return 1;
	return 0;
}

/**
 *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
 *	@adev: ATA device
 *
 *	Compute the highest mode possible if we are not using iordy. Return
 *	-1 if no iordy mode is available.
 */

static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
{
	/* If we have no drive specific rule, then PIO 2 is non IORDY */
	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
		u16 pio = adev->id[ATA_ID_EIDE_PIO];
		/* Is the speed faster than the drive allows non IORDY ? */
		if (pio) {
			/* This is cycle times not frequency - watch the logic! */
			if (pio > 240)	/* PIO2 is 240nS per cycle */
				return 3 << ATA_SHIFT_PIO;
			return 7 << ATA_SHIFT_PIO;
		}
	}
	return 3 << ATA_SHIFT_PIO;
}

/**
 *	ata_dev_read_id - Read ID data from the specified device
 *	@dev: target device
 *	@p_class: pointer to class of the target device (may be changed)
 *	@flags: ATA_READID_* flags
 *	@id: buffer to read IDENTIFY data into
 *
 *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
 *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
 *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
 *	for pre-ATA4 drives.
 *
 *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
 *	now we abort if we hit that case.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep)
 *
 *	RETURNS:
 *	0 on success, -errno otherwise.
 */
int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
		    unsigned int flags, u16 *id)
{
	struct ata_port *ap = dev->link->ap;
	unsigned int class = *p_class;
	struct ata_taskfile tf;
	unsigned int err_mask = 0;
	const char *reason;
	int may_fallback = 1, tried_spinup = 0;
	int rc;

	if (ata_msg_ctl(ap))
		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __FUNCTION__);

	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
 retry:
	ata_tf_init(dev, &tf);

	switch (class) {
	case ATA_DEV_ATA:
		tf.command = ATA_CMD_ID_ATA;
		break;
	case ATA_DEV_ATAPI:
		tf.command = ATA_CMD_ID_ATAPI;
		break;
	default:
		rc = -ENODEV;
		reason = "unsupported class";
		goto err_out;
	}

	tf.protocol = ATA_PROT_PIO;

	/* Some devices choke if TF registers contain garbage.  Make
	 * sure those are properly initialized.
	 */
	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;

	/* Device presence detection is unreliable on some
	 * controllers.  Always poll IDENTIFY if available.
	 */
	tf.flags |= ATA_TFLAG_POLLING;

	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
	if (err_mask) {
		if (err_mask & AC_ERR_NODEV_HINT) {
			DPRINTK("ata%u.%d: NODEV after polling detection\n",
				ap->print_id, dev->devno);
			return -ENOENT;
		}

		/* Device or controller might have reported the wrong
		 * device class.  Give a shot at the other IDENTIFY if
		 * the current one is aborted by the device.
		 */
		if (may_fallback &&
		    (err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
			may_fallback = 0;

			if (class == ATA_DEV_ATA)
				class = ATA_DEV_ATAPI;
			else
				class = ATA_DEV_ATA;
			goto retry;
		}

		rc = -EIO;
		reason = "I/O error";
		goto err_out;
	}

	/* Falling back doesn't make sense if ID data was read
	 * successfully at least once.
	 */
	may_fallback = 0;

	swap_buf_le16(id, ATA_ID_WORDS);

	/* sanity check */
	rc = -EINVAL;
	reason = "device reports invalid type";

	if (class == ATA_DEV_ATA) {
		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
			goto err_out;
	} else {
		if (ata_id_is_ata(id))
			goto err_out;
	}

	if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
		tried_spinup = 1;
		/*
		 * Drive powered-up in standby mode, and requires a specific
		 * SET_FEATURES spin-up subcommand before it will accept
		 * anything other than the original IDENTIFY command.
		 */
		err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
		if (err_mask && id[2] != 0x738c) {
			rc = -EIO;
			reason = "SPINUP failed";
			goto err_out;
		}
		/*
		 * If the drive initially returned incomplete IDENTIFY info,
		 * we now must reissue the IDENTIFY command.
		 */
		if (id[2] == 0x37c8)
			goto retry;
	}

	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
		/*
		 * The exact sequence expected by certain pre-ATA4 drives is:
		 * SRST RESET
		 * IDENTIFY (optional in early ATA)
		 * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
		 * anything else..
		 * Some drives were very specific about that exact sequence.
		 *
		 * Note that ATA4 says lba is mandatory so the second check
		 * shoud never trigger.
		 */
		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
			err_mask = ata_dev_init_params(dev, id[3], id[6]);
			if (err_mask) {
				rc = -EIO;
				reason = "INIT_DEV_PARAMS failed";
				goto err_out;
			}

			/* current CHS translation info (id[53-58]) might be
			 * changed. reread the identify device info.
			 */
			flags &= ~ATA_READID_POSTRESET;
			goto retry;
		}
	}

	*p_class = class;

	return 0;

 err_out:
	if (ata_msg_warn(ap))
		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
			       "(%s, err_mask=0x%x)\n", reason, err_mask);
	return rc;
}

static inline u8 ata_dev_knobble(struct ata_device *dev)
{
	struct ata_port *ap = dev->link->ap;
	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
}

static void ata_dev_config_ncq(struct ata_device *dev,
			       char *desc, size_t desc_sz)
{
	struct ata_port *ap = dev->link->ap;
	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);

	if (!ata_id_has_ncq(dev->id)) {
		desc[0] = '\0';
		return;
	}
	if (dev->horkage & ATA_HORKAGE_NONCQ) {
		snprintf(desc, desc_sz, "NCQ (not used)");
		return;
	}
	if (ap->flags & ATA_FLAG_NCQ) {
		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);