patch 6/8:
- Delegate irq driven pio to workqueue.
- HSM_ST_LAST is kept in the interrupt since this is not CPU intensive.
(Mostly for DMA and non-data.)
Signed-off-by: Albert Lee <albertcc@xxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Tejun Heo <htejun@xxxxxxxxx>
---
sata_sil is not changed to delegate to workqueue at this moment.
Maybe we can add such feature in the future if needed.
diff -Nrup 05_polling_ack/drivers/ata/libata-core.c 06_irq_wq/drivers/ata/libata-core.c
--- 05_polling_ack/drivers/ata/libata-core.c 2007-05-16 13:53:20.000000000 +0800
+++ 06_irq_wq/drivers/ata/libata-core.c 2007-05-16 13:53:25.000000000 +0800
@@ -4864,20 +4864,15 @@ err_out:
static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
{
- if (qc->tf.flags & ATA_TFLAG_POLLING)
- return 1;
-
- if (ap->hsm_task_state == HSM_ST_FIRST) {
- if (qc->tf.protocol == ATA_PROT_PIO &&
- (qc->tf.flags & ATA_TFLAG_WRITE))
- return 1;
-
- if (is_atapi_taskfile(&qc->tf) &&
- !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
- return 1;
+ switch (qc->tf.protocol) {
+ case ATA_PROT_DMA:
+ return 0;
+ case ATA_PROT_ATAPI_DMA:
+ if (ap->hsm_task_state != HSM_ST_FIRST)
+ return 0;
}
- return 0;
+ return (ap->pflags & ATA_PFLAG_HSM_WQ) ? 1 : 0;
}
/**
@@ -5217,6 +5212,39 @@ fsm_start:
}
/**
+ * ata_irq_task - queue task for irq pio
+ * @work: associated work_struct
+ *
+ * LOCKING:
+ * None.
+ */
+
+static void ata_irq_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;
+ u8 status;
+
+ WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
+
+ /* double check the device is not busy */
+ status = ata_chk_status(ap);
+ if (status & ATA_BUSY) {
+ ata_port_printk(ap, KERN_ERR, "Unexpected device busy "
+ "(Status 0x%x)\n", status);
+ return;
+ }
+
+ /* move the HSM */
+ ata_hsm_move(ap, qc, status, 1);
+
+ /* another command or interrupt handler
+ * may be running at this point.
+ */
+}
+
+/**
* ata_qc_new - Request an available ATA command, for queueing
* @ap: Port associated with device @dev
* @dev: Device from whom we request an available command structure
@@ -5756,11 +5784,21 @@ inline unsigned int ata_host_intr (struc
/* ack bmdma irq events */
ap->ops->irq_clear(ap);
- ata_hsm_move(ap, qc, status, 0);
+ /* move the HSM */
+ switch (ap->hsm_task_state) {
+ case HSM_ST_FIRST:
+ case HSM_ST:
+ /* delegate PIO data transfer to workqueue */
+ ap->pflags |= ATA_PFLAG_HSM_WQ;
+ ata_port_queue_task(ap, ata_irq_task, qc, 0);
+ break;
+ default:
+ ata_hsm_move(ap, qc, status, 0);
- if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
- qc->tf.protocol == ATA_PROT_ATAPI_DMA))
- ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
+ if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
+ qc->tf.protocol == ATA_PROT_ATAPI_DMA))
+ ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
+ }
return 1; /* irq handled */
-
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