Tasklets have long been deprecated as being too heavy on the system
by running in irq context - and this is not a performance critical
path. If a higher priority process wants to run, it must wait for
the tasklet to finish before doing so.
Process srps asynchronously in process context in a dedicated
single threaded workqueue.
Cc: Tyrel Datwyler <tyr...@linux.ibm.com>
Cc: Michael Ellerman <m...@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Davidlohr Bueso <d...@stgolabs.net>
---
drivers/scsi/ibmvscsi/ibmvscsi.c | 38 ++++++++++++++++++++++----------
drivers/scsi/ibmvscsi/ibmvscsi.h | 3 ++-
2 files changed, 28 insertions(+), 13 deletions(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 63f32f843e75..37cbea8bb0af 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -86,6 +86,8 @@ static DEFINE_SPINLOCK(ibmvscsi_driver_lock);
static struct scsi_transport_template *ibmvscsi_transport_template;
+static struct workqueue_struct *ibmvscsi_wq;
+
#define IBMVSCSI_VERSION "1.5.9"
MODULE_DESCRIPTION("IBM Virtual SCSI");
@@ -117,7 +119,7 @@ static void ibmvscsi_handle_crq(struct viosrp_crq *crq,
* @irq: number of irq to handle, not used
* @dev_instance: ibmvscsi_host_data of host that received interrupt
*
- * Disables interrupts and schedules srp_task
+ * Disables interrupts and schedules srp_work
* Always returns IRQ_HANDLED
*/
static irqreturn_t ibmvscsi_handle_event(int irq, void *dev_instance)
@@ -125,7 +127,7 @@ static irqreturn_t ibmvscsi_handle_event(int irq, void
*dev_instance)
struct ibmvscsi_host_data *hostdata =
(struct ibmvscsi_host_data *)dev_instance;
vio_disable_interrupts(to_vio_dev(hostdata->dev));
- tasklet_schedule(&hostdata->srp_task);
+ queue_work(ibmvscsi_wq, &hostdata->srp_work);
return IRQ_HANDLED;
}
@@ -145,7 +147,7 @@ static void ibmvscsi_release_crq_queue(struct crq_queue
*queue,
long rc = 0;
struct vio_dev *vdev = to_vio_dev(hostdata->dev);
free_irq(vdev->irq, (void *)hostdata);
- tasklet_kill(&hostdata->srp_task);
+ cancel_work_sync(&hostdata->srp_work);
do {
if (rc)
msleep(100);
@@ -206,16 +208,19 @@ static int ibmvscsi_send_crq(struct ibmvscsi_host_data
*hostdata,
}
/**
- * ibmvscsi_task: - Process srps asynchronously
+ * ibmvscsi_workfn: - Process srps asynchronously
* @data: ibmvscsi_host_data of host
*/
-static void ibmvscsi_task(void *data)
+static void ibmvscsi_workfn(struct work_struct *work)
{
- struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
- struct vio_dev *vdev = to_vio_dev(hostdata->dev);
+ struct ibmvscsi_host_data *hostdata;
+ struct vio_dev *vdev;
struct viosrp_crq *crq;
int done = 0;
+ hostdata = container_of(work, struct ibmvscsi_host_data, srp_work);
+ vdev = to_vio_dev(hostdata->dev);
+
while (!done) {
/* Pull all the valid messages off the CRQ */
while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
@@ -367,8 +372,7 @@ static int ibmvscsi_init_crq_queue(struct crq_queue *queue,
queue->cur = 0;
spin_lock_init(&queue->lock);
- tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
- (unsigned long)hostdata);
+ INIT_WORK(&hostdata->srp_work, ibmvscsi_workfn);
if (request_irq(vdev->irq,
ibmvscsi_handle_event,
@@ -387,7 +391,7 @@ static int ibmvscsi_init_crq_queue(struct crq_queue *queue,
return retrc;
req_irq_failed:
- tasklet_kill(&hostdata->srp_task);
+ cancel_work_sync(&hostdata->srp_work);
rc = 0;
do {
if (rc)
@@ -2371,7 +2375,7 @@ static int ibmvscsi_resume(struct device *dev)
{
struct ibmvscsi_host_data *hostdata = dev_get_drvdata(dev);
vio_disable_interrupts(to_vio_dev(hostdata->dev));
- tasklet_schedule(&hostdata->srp_task);
+ queue_work(ibmvscsi_wq, &hostdata->srp_work);
return 0;
}
@@ -2418,15 +2422,25 @@ static int __init ibmvscsi_module_init(void)
if (!ibmvscsi_transport_template)
return -ENOMEM;
+ ibmvscsi_wq = alloc_ordered_workqueue("ibmvscsi_wq", 0);
+ if (!ibmvscsi_wq) {
+ srp_release_transport(ibmvscsi_transport_template);
+ return -ENOMEM;
+ }
+
ret = vio_register_driver(&ibmvscsi_driver);
- if (ret)
+ if (ret) {
+ destroy_workqueue(ibmvscsi_wq);
srp_release_transport(ibmvscsi_transport_template);
+ }
+
return ret;
}
static void __exit ibmvscsi_module_exit(void)
{
vio_unregister_driver(&ibmvscsi_driver);
+ destroy_workqueue(ibmvscsi_wq);
srp_release_transport(ibmvscsi_transport_template);
}
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.h b/drivers/scsi/ibmvscsi/ibmvscsi.h
index e60916ef7a49..f7c52744a206 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.h
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.h
@@ -18,6 +18,7 @@
#include <linux/types.h>
#include <linux/list.h>
#include <linux/completion.h>
+#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <scsi/viosrp.h>
@@ -90,7 +91,7 @@ struct ibmvscsi_host_data {
struct device *dev;
struct event_pool pool;
struct crq_queue queue;
- struct tasklet_struct srp_task;
+ struct work_struct srp_work;
struct list_head sent;
struct Scsi_Host *host;
struct task_struct *work_thread;
--
2.36.1
