libata-sff: port_task is SFF specific
port_task is tightly bound to the standard SFF PIO HSM implementation.
Using it for any other purpose would be error-prone and there's no
such user and if some drivers need such feature, it would be much
better off using its own. Move it inside CONFIG_ATA_SFF and rename it
to sff_pio_task.
The only function which is exposed to the core layer is
ata_sff_flush_pio_task() which is renamed from ata_port_flush_task()
and now also takes care of resetting hsm_task_state to HSM_ST_IDLE,
which is possible as it's now specific to PIO HSM.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 8a1396f..e78ad768 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -40,6 +40,8 @@
#include "libata.h"
+static struct workqueue_struct *ata_sff_wq;
+
const struct ata_port_operations ata_sff_port_ops = {
.inherits = &ata_base_port_ops,
@@ -1293,7 +1295,7 @@
if (in_wq)
spin_unlock_irqrestore(ap->lock, flags);
- /* if polling, ata_pio_task() handles the rest.
+ /* if polling, ata_sff_pio_task() handles the rest.
* otherwise, interrupt handler takes over from here.
*/
break;
@@ -1458,14 +1460,38 @@
}
EXPORT_SYMBOL_GPL(ata_sff_hsm_move);
-void ata_pio_task(struct work_struct *work)
+void ata_sff_queue_pio_task(struct ata_port *ap, unsigned long delay)
+{
+ /* may fail if ata_sff_flush_pio_task() in progress */
+ queue_delayed_work(ata_sff_wq, &ap->sff_pio_task,
+ msecs_to_jiffies(delay));
+}
+EXPORT_SYMBOL_GPL(ata_sff_queue_pio_task);
+
+void ata_sff_flush_pio_task(struct ata_port *ap)
+{
+ DPRINTK("ENTER\n");
+
+ cancel_rearming_delayed_work(&ap->sff_pio_task);
+ ap->hsm_task_state = HSM_ST_IDLE;
+
+ if (ata_msg_ctl(ap))
+ ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __func__);
+}
+
+static void ata_sff_pio_task(struct work_struct *work)
{
struct ata_port *ap =
- container_of(work, struct ata_port, port_task.work);
- struct ata_queued_cmd *qc = ap->port_task_data;
+ container_of(work, struct ata_port, sff_pio_task.work);
+ struct ata_queued_cmd *qc;
u8 status;
int poll_next;
+ /* qc can be NULL if timeout occurred */
+ qc = ata_qc_from_tag(ap, ap->link.active_tag);
+ if (!qc)
+ return;
+
fsm_start:
WARN_ON_ONCE(ap->hsm_task_state == HSM_ST_IDLE);
@@ -1481,7 +1507,7 @@
msleep(2);
status = ata_sff_busy_wait(ap, ATA_BUSY, 10);
if (status & ATA_BUSY) {
- ata_pio_queue_task(ap, qc, ATA_SHORT_PAUSE);
+ ata_sff_queue_pio_task(ap, ATA_SHORT_PAUSE);
return;
}
}
@@ -1551,7 +1577,7 @@
ap->hsm_task_state = HSM_ST_LAST;
if (qc->tf.flags & ATA_TFLAG_POLLING)
- ata_pio_queue_task(ap, qc, 0);
+ ata_sff_queue_pio_task(ap, 0);
break;
@@ -1573,20 +1599,21 @@
if (qc->tf.flags & ATA_TFLAG_WRITE) {
/* PIO data out protocol */
ap->hsm_task_state = HSM_ST_FIRST;
- ata_pio_queue_task(ap, qc, 0);
+ ata_sff_queue_pio_task(ap, 0);
- /* always send first data block using
- * the ata_pio_task() codepath.
+ /* always send first data block using the
+ * ata_sff_pio_task() codepath.
*/
} else {
/* PIO data in protocol */
ap->hsm_task_state = HSM_ST;
if (qc->tf.flags & ATA_TFLAG_POLLING)
- ata_pio_queue_task(ap, qc, 0);
+ ata_sff_queue_pio_task(ap, 0);
- /* if polling, ata_pio_task() handles the rest.
- * otherwise, interrupt handler takes over from here.
+ /* if polling, ata_sff_pio_task() handles the
+ * rest. otherwise, interrupt handler takes
+ * over from here.
*/
}
@@ -1604,7 +1631,7 @@
/* send cdb by polling if no cdb interrupt */
if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
(qc->tf.flags & ATA_TFLAG_POLLING))
- ata_pio_queue_task(ap, qc, 0);
+ ata_sff_queue_pio_task(ap, 0);
break;
case ATAPI_PROT_DMA:
@@ -1616,7 +1643,7 @@
/* send cdb by polling if no cdb interrupt */
if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
- ata_pio_queue_task(ap, qc, 0);
+ ata_sff_queue_pio_task(ap, 0);
break;
default:
@@ -2360,8 +2387,6 @@
/* reset PIO HSM and stop DMA engine */
spin_lock_irqsave(ap->lock, flags);
- ap->hsm_task_state = HSM_ST_IDLE;
-
if (ap->ioaddr.bmdma_addr &&
qc && (qc->tf.protocol == ATA_PROT_DMA ||
qc->tf.protocol == ATAPI_PROT_DMA)) {
@@ -2432,8 +2457,6 @@
spin_lock_irqsave(ap->lock, flags);
- ap->hsm_task_state = HSM_ST_IDLE;
-
if (ap->ioaddr.bmdma_addr)
ap->ops->bmdma_stop(qc);
@@ -3074,15 +3097,28 @@
*/
void ata_sff_port_init(struct ata_port *ap)
{
+ INIT_DELAYED_WORK(&ap->sff_pio_task, ata_sff_pio_task);
ap->ctl = ATA_DEVCTL_OBS;
ap->last_ctl = 0xFF;
}
int __init ata_sff_init(void)
{
+ /*
+ * FIXME: In UP case, there is only one workqueue thread and if you
+ * have more than one PIO device, latency is bloody awful, with
+ * occasional multi-second "hiccups" as one PIO device waits for
+ * another. It's an ugly wart that users DO occasionally complain
+ * about; luckily most users have at most one PIO polled device.
+ */
+ ata_sff_wq = create_workqueue("ata_sff");
+ if (!ata_sff_wq)
+ return -ENOMEM;
+
return 0;
}
void __exit ata_sff_exit(void)
{
+ destroy_workqueue(ata_sff_wq);
}