Implement NCQ helper function ata_ncq_complete(). This function takes
the current value of SActive, compares it against ap->sactive and
invoke ata_qc_complete() on all finished commands. This function is
to be used by interrupt handlers implementing NCQ.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/libata-core.c | 47 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/libata.h | 1 +
2 files changed, 48 insertions(+), 0 deletions(-)
429f220dc61c1d67cedbbc7da9eb9f52b20c2271
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 56637f0..fa941cc 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -4574,6 +4574,52 @@ irqreturn_t ata_interrupt (int irq, void
return IRQ_RETVAL(handled);
}
+/**
+ * ata_ncq_complete - NCQ driver helper. Complete requests normally.
+ * @ap: port in question
+ * @sactive: current SActive value
+ *
+ * Complete in-flight commands. One device per port is assumed.
+ * This functions is meant to be called from low-level driver's
+ * interrupt routine to complete requests normally. On
+ * invocation, if non-NCQ command was in-flight, it's completed
+ * normally. If NCQ commands were in-flight, cached ap->sactive
+ * and new @sactive is compared and commands are completed
+ * accordingly.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ *
+ * RETURNS:
+ * Number of completed commands on success, -errno otherwise.
+ */
+int ata_ncq_complete(struct ata_port *ap, u32 sactive)
+{
+ int nr_done = 0;
+ unsigned long done_mask = 0;
+ int i;
+
+ if (ap->sactive) {
+ done_mask = ap->sactive ^ sactive;
+
+ if (unlikely(done_mask & sactive)) {
+ printk(KERN_ERR "ata%u: illegal sactive transition "
+ "(%08x->%08x)\n", ap->id, ap->sactive, sactive);
+ return -EINVAL;
+ }
+ } else if (ap->active_tag != ATA_TAG_POISON)
+ done_mask = 1 << ap->active_tag;
+
+ for (i = 0; i < ATA_MAX_QUEUE; i++) {
+ struct ata_queued_cmd *qc = ata_qc_from_tag(ap, i);
+ if (done_mask & (1 << i) && qc) {
+ ata_qc_complete(qc);
+ nr_done++;
+ }
+ }
+
+ return nr_done;
+}
/*
* Execute a 'simple' command, that only consists of the opcode 'cmd' itself,
@@ -5300,6 +5346,7 @@ EXPORT_SYMBOL_GPL(ata_scsi_slave_config)
EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
EXPORT_SYMBOL_GPL(ata_scsi_release);
EXPORT_SYMBOL_GPL(ata_host_intr);
+EXPORT_SYMBOL_GPL(ata_ncq_complete);
EXPORT_SYMBOL_GPL(ata_id_string);
EXPORT_SYMBOL_GPL(ata_id_c_string);
EXPORT_SYMBOL_GPL(ata_scsi_simulate);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9ae1f03..b9abfb3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -580,6 +580,7 @@ extern int ata_scsi_ioctl(struct scsi_de
extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
extern int ata_scsi_release(struct Scsi_Host *host);
extern unsigned int ata_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc);
+extern int ata_ncq_complete(struct ata_port *ap, u32 sactive);
extern int ata_scsi_device_resume(struct scsi_device *);
extern int ata_scsi_device_suspend(struct scsi_device *, pm_message_t state);
extern int ata_device_resume(struct ata_port *, struct ata_device *);
--
1.2.4
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