Commit d06b487b authored by Dan Williams's avatar Dan Williams
Browse files

isci: implement I_T_nexus_reset 



This is a requirement for 2.6.39's new libata eh.

Still some questions about lldd_dev_gone racing against dev->lldd_dev
lookups, but we are at least no more broken than mvsas in this regard.

We also short-circuit I_T_nexus_reset invocations from the device
discovery path (IDEV_EH similar to MVS_DEV_EH) to filter out the
resulting domain rediscoveries triggered by the reset.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 5b3f2bd8

drivers/scsi/isci/remote_device.c

+1 −0
Original line number Diff line number Diff line
@@ -891,6 +891,7 @@ static void isci_remote_device_deconstruct(struct isci_host *ihost, struct isci_ 


	clear_bit(IDEV_START_PENDING, &idev->flags);

	clear_bit(IDEV_STOP_PENDING, &idev->flags);

	clear_bit(IDEV_EH, &idev->flags);

	wake_up(&ihost->eventq);

}

drivers/scsi/isci/remote_device.h

+1 −0
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ struct isci_remote_device { 
	#define IDEV_START_PENDING 0

	#define IDEV_STOP_PENDING 1

	#define IDEV_ALLOCATED 2

	#define IDEV_EH 3

	unsigned long flags;

	struct isci_port *isci_port;

	struct domain_device *domain_dev;

drivers/scsi/isci/task.c

+74 −64
Original line number Diff line number Diff line
@@ -1022,9 +1022,11 @@ int isci_task_lu_reset(struct domain_device *domain_device, u8 *lun) 
		"%s: domain_device=%p, isci_host=%p; isci_device=%p\n",

		 __func__, domain_device, isci_host, isci_device);



	if (isci_device != NULL)

	if (isci_device != NULL) {

		device_stopping = (isci_device->status == isci_stopping)

				  || (isci_device->status == isci_stopped);

		set_bit(IDEV_EH, &isci_device->flags);

	}



	/* If there is a device reset pending on any request in the

	 * device's list, fail this LUN reset request in order to
@@ -1069,12 +1071,6 @@ int isci_task_clear_nexus_ha(struct sas_ha_struct *ha) 
	return TMF_RESP_FUNC_FAILED;

}



int isci_task_I_T_nexus_reset(struct domain_device *dev)

{

	return TMF_RESP_FUNC_FAILED;

}





/* Task Management Functions. Must be called from process context.	 */



/**
@@ -1171,6 +1167,12 @@ int isci_task_abort_task(struct sas_task *task) 
	device_stopping = (isci_device->status == isci_stopping)

			  || (isci_device->status == isci_stopped);



	/* XXX need to fix device lookup lifetime (needs to be done

	 * under scic_lock, among other things...), but for now assume

	 * the device is available like the above code

	 */

	set_bit(IDEV_EH, &isci_device->flags);



	/* This version of the driver will fail abort requests for

	 * SATA/STP.  Failing the abort request this way will cause the

	 * SCSI error handler thread to escalate to LUN reset
@@ -1481,86 +1483,94 @@ isci_task_request_complete(struct isci_host *ihost, 
	complete(tmf_complete);

}



/**

 * isci_bus_reset_handler() - This function performs a target reset of the

 *    device referenced by "cmd'.  This function is exported through the

 *    "struct scsi_host_template" structure such that it is called when an I/O

 *    recovery process has escalated to a target reset. Note that this function

 *    is called from the scsi error handler event thread, so may block on calls.

 * @scsi_cmd: This parameter specifies the target to be reset.

 *

 * SUCCESS if the reset process was successful, else FAILED.

 */

int isci_bus_reset_handler(struct scsi_cmnd *cmd)

static int isci_reset_device(struct domain_device *dev, int hard_reset)

{

	struct domain_device *dev = cmd_to_domain_dev(cmd);

	struct isci_host *isci_host = dev_to_ihost(dev);

	unsigned long flags = 0;

	struct isci_remote_device *idev = dev->lldd_dev;

	struct sas_phy *phy = sas_find_local_phy(dev);

	struct isci_host *ihost = dev_to_ihost(dev);

	enum sci_status status;

	int base_status;

	struct isci_remote_device *isci_dev = dev->lldd_dev;

	unsigned long flags;

	int rc;



	dev_dbg(&isci_host->pdev->dev,

		"%s: cmd %p, isci_dev %p\n",

		__func__, cmd, isci_dev);

	dev_dbg(&ihost->pdev->dev, "%s: idev %p\n", __func__, idev);



	if (!isci_dev) {

		dev_warn(&isci_host->pdev->dev,

			 "%s: isci_dev is GONE!\n",

	if (!idev) {

		dev_warn(&ihost->pdev->dev,

			 "%s: idev is GONE!\n",

			 __func__);



		return TMF_RESP_FUNC_COMPLETE; /* Nothing to reset. */

	}



	spin_lock_irqsave(&isci_host->scic_lock, flags);

	status = scic_remote_device_reset(&isci_dev->sci);

	spin_lock_irqsave(&ihost->scic_lock, flags);

	status = scic_remote_device_reset(&idev->sci);

	if (status != SCI_SUCCESS) {

		spin_unlock_irqrestore(&isci_host->scic_lock, flags);

		spin_unlock_irqrestore(&ihost->scic_lock, flags);



		scmd_printk(KERN_WARNING, cmd,

		dev_warn(&ihost->pdev->dev,

			 "%s: scic_remote_device_reset(%p) returned %d!\n",

			    __func__, isci_dev, status);

			 __func__, idev, status);



		return TMF_RESP_FUNC_FAILED;

	}

	spin_unlock_irqrestore(&isci_host->scic_lock, flags);

	spin_unlock_irqrestore(&ihost->scic_lock, flags);



	/* Make sure all pending requests are able to be fully terminated. */

	isci_device_clear_reset_pending(isci_host, isci_dev);

	isci_device_clear_reset_pending(ihost, idev);



	rc = sas_phy_reset(phy, hard_reset);

	msleep(2000); /* just like mvsas */



	/* Terminate in-progress I/O now. */

	isci_remote_device_nuke_requests(isci_host, isci_dev);

	isci_remote_device_nuke_requests(ihost, idev);



	spin_lock_irqsave(&ihost->scic_lock, flags);

	status = scic_remote_device_reset_complete(&idev->sci);

	spin_unlock_irqrestore(&ihost->scic_lock, flags);



	/* Call into the libsas default handler (which calls sas_phy_reset). */

	base_status = sas_eh_bus_reset_handler(cmd);

	if (status != SCI_SUCCESS) {

		dev_warn(&ihost->pdev->dev,

			 "%s: scic_remote_device_reset_complete(%p) "

			 "returned %d!\n", __func__, idev, status);

	}



	if (base_status != SUCCESS) {

	dev_dbg(&ihost->pdev->dev, "%s: idev %p complete.\n", __func__, idev);



		/* There can be cases where the resets to individual devices

		 * behind an expander will fail because of an unplug of the

		 * expander itself.

		 */

		scmd_printk(KERN_WARNING, cmd,

			    "%s: sas_eh_bus_reset_handler(%p) returned %d!\n",

			    __func__, cmd, base_status);

	return rc;

}



	/* WHAT TO DO HERE IF sas_phy_reset FAILS? */

	spin_lock_irqsave(&isci_host->scic_lock, flags);

	status = scic_remote_device_reset_complete(&isci_dev->sci);

	spin_unlock_irqrestore(&isci_host->scic_lock, flags);

int isci_task_I_T_nexus_reset(struct domain_device *dev)

{

	struct isci_host *ihost = dev_to_ihost(dev);

	int ret = TMF_RESP_FUNC_FAILED, hard_reset = 1;

	struct isci_remote_device *idev;

	unsigned long flags;



	if (status != SCI_SUCCESS) {

		scmd_printk(KERN_WARNING, cmd,

			    "%s: scic_remote_device_reset_complete(%p) "

			    "returned %d!\n",

			    __func__, isci_dev, status);

	/* XXX mvsas is not protecting against ->lldd_dev_gone(), are we

	 * being too paranoid, or is mvsas busted?!

	 */

	spin_lock_irqsave(&ihost->scic_lock, flags);

	idev = dev->lldd_dev;

	if (!idev || !test_bit(IDEV_EH, &idev->flags))

		ret = TMF_RESP_FUNC_COMPLETE;

	spin_unlock_irqrestore(&ihost->scic_lock, flags);



	if (ret == TMF_RESP_FUNC_COMPLETE)

		return ret;



	if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP))

		hard_reset = 0;



	return isci_reset_device(dev, hard_reset);

}

	/* WHAT TO DO HERE IF scic_remote_device_reset_complete FAILS? */



	dev_dbg(&isci_host->pdev->dev,

		"%s: cmd %p, isci_dev %p complete.\n",

		__func__, cmd, isci_dev);

int isci_bus_reset_handler(struct scsi_cmnd *cmd)

{

	struct domain_device *dev = sdev_to_domain_dev(cmd->device);

	int hard_reset = 1;



	return TMF_RESP_FUNC_COMPLETE;

	if (dev->dev_type == SATA_DEV || (dev->tproto & SAS_PROTOCOL_STP))

		hard_reset = 0;



	return isci_reset_device(dev, hard_reset);

}

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