Commit 6e40de8b authored by Tyrel Datwyler's avatar Tyrel Datwyler Committed by Martin K. Petersen
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scsi: ibmvscsi: redo driver work thread to use enum action states 



The current implemenation relies on two flags in the driver's private host
structure to signal the need for a host reset or to reenable the CRQ after
a LPAR migration. This patch does away with those flags and introduces a
single action flag and defined enums for the supported kthread work
actions. Lastly, the if/else logic is replaced with a switch statement.

Signed-off-by: default avatarTyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 2e225204

drivers/scsi/ibmvscsi/ibmvscsi.c

+42 −19
Original line number Diff line number Diff line
@@ -828,7 +828,7 @@ static void ibmvscsi_reset_host(struct ibmvscsi_host_data *hostdata) 
	atomic_set(&hostdata->request_limit, 0);



	purge_requests(hostdata, DID_ERROR);

	hostdata->reset_crq = 1;

	hostdata->action = IBMVSCSI_HOST_ACTION_RESET;

	wake_up(&hostdata->work_wait_q);

}
@@ -1797,7 +1797,7 @@ static void ibmvscsi_handle_crq(struct viosrp_crq *crq, 
			/* We need to re-setup the interpartition connection */

			dev_info(hostdata->dev, "Re-enabling adapter!\n");

			hostdata->client_migrated = 1;

			hostdata->reenable_crq = 1;

			hostdata->action = IBMVSCSI_HOST_ACTION_REENABLE;

			purge_requests(hostdata, DID_REQUEUE);

			wake_up(&hostdata->work_wait_q);

		} else {
@@ -2116,48 +2116,71 @@ static unsigned long ibmvscsi_get_desired_dma(struct vio_dev *vdev) 


static void ibmvscsi_do_work(struct ibmvscsi_host_data *hostdata)

{

	unsigned long flags;

	int rc;

	char *action = "reset";



	if (hostdata->reset_crq) {

		smp_rmb();

		hostdata->reset_crq = 0;



	spin_lock_irqsave(hostdata->host->host_lock, flags);

	switch (hostdata->action) {

	case IBMVSCSI_HOST_ACTION_NONE:

		break;

	case IBMVSCSI_HOST_ACTION_RESET:

		spin_unlock_irqrestore(hostdata->host->host_lock, flags);

		rc = ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);

		spin_lock_irqsave(hostdata->host->host_lock, flags);

		if (!rc)

			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);

		vio_enable_interrupts(to_vio_dev(hostdata->dev));

	} else if (hostdata->reenable_crq) {

		smp_rmb();

		break;

	case IBMVSCSI_HOST_ACTION_REENABLE:

		action = "enable";

		spin_unlock_irqrestore(hostdata->host->host_lock, flags);

		rc = ibmvscsi_reenable_crq_queue(&hostdata->queue, hostdata);

		hostdata->reenable_crq = 0;

		spin_lock_irqsave(hostdata->host->host_lock, flags);

		if (!rc)

			rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);

	} else

		return;

		break;

	default:

		break;

	}



	hostdata->action = IBMVSCSI_HOST_ACTION_NONE;



	if (rc) {

		atomic_set(&hostdata->request_limit, -1);

		dev_err(hostdata->dev, "error after %s\n", action);

	}

	spin_unlock_irqrestore(hostdata->host->host_lock, flags);



	scsi_unblock_requests(hostdata->host);

}



static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)

static int __ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)

{

	if (kthread_should_stop())

		return 1;

	else if (hostdata->reset_crq) {

		smp_rmb();

		return 1;

	} else if (hostdata->reenable_crq) {

		smp_rmb();

	switch (hostdata->action) {

	case IBMVSCSI_HOST_ACTION_NONE:

		return 0;

	case IBMVSCSI_HOST_ACTION_RESET:

	case IBMVSCSI_HOST_ACTION_REENABLE:

	default:

		break;

	}



	return 1;

}



	return 0;

static int ibmvscsi_work_to_do(struct ibmvscsi_host_data *hostdata)

{

	unsigned long flags;

	int rc;



	spin_lock_irqsave(hostdata->host->host_lock, flags);

	rc = __ibmvscsi_work_to_do(hostdata);

	spin_unlock_irqrestore(hostdata->host->host_lock, flags);



	return rc;

}



static int ibmvscsi_work(void *data)

drivers/scsi/ibmvscsi/ibmvscsi.h

+7 −2
Original line number Diff line number Diff line
@@ -88,13 +88,18 @@ struct event_pool { 
	dma_addr_t iu_token;

};



enum ibmvscsi_host_action {

	IBMVSCSI_HOST_ACTION_NONE = 0,

	IBMVSCSI_HOST_ACTION_RESET,

	IBMVSCSI_HOST_ACTION_REENABLE,

};



/* all driver data associated with a host adapter */

struct ibmvscsi_host_data {

	struct list_head host_list;

	atomic_t request_limit;

	int client_migrated;

	int reset_crq;

	int reenable_crq;

	enum ibmvscsi_host_action action;

	struct device *dev;

	struct event_pool pool;

	struct crq_queue queue;

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