libata: use WARN_ON_ONCE on hot paths

Convert WARN_ON() on command issue/completion paths to WARN_ON_ONCE()
so that libata doesn't spam the machine even when one of those
conditions triggers repeatedly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index c59ad76..0eae9b4 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -578,7 +578,7 @@
 	}
 
 	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
-		WARN_ON(!ioaddr->ctl_addr);
+		WARN_ON_ONCE(!ioaddr->ctl_addr);
 		iowrite8(tf->hob_feature, ioaddr->feature_addr);
 		iowrite8(tf->hob_nsect, ioaddr->nsect_addr);
 		iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
@@ -651,7 +651,7 @@
 			iowrite8(tf->ctl, ioaddr->ctl_addr);
 			ap->last_ctl = tf->ctl;
 		} else
-			WARN_ON(1);
+			WARN_ON_ONCE(1);
 	}
 }
 EXPORT_SYMBOL_GPL(ata_sff_tf_read);
@@ -891,7 +891,7 @@
 		/* READ/WRITE MULTIPLE */
 		unsigned int nsect;
 
-		WARN_ON(qc->dev->multi_count == 0);
+		WARN_ON_ONCE(qc->dev->multi_count == 0);
 
 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
 			    qc->dev->multi_count);
@@ -918,7 +918,7 @@
 {
 	/* send SCSI cdb */
 	DPRINTK("send cdb\n");
-	WARN_ON(qc->dev->cdb_len < 12);
+	WARN_ON_ONCE(qc->dev->cdb_len < 12);
 
 	ap->ops->sff_data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
 	ata_sff_sync(ap);
@@ -1014,7 +1014,7 @@
 	}
 
 	/* consumed can be larger than count only for the last transfer */
-	WARN_ON(qc->cursg && count != consumed);
+	WARN_ON_ONCE(qc->cursg && count != consumed);
 
 	if (bytes)
 		goto next_sg;
@@ -1172,13 +1172,13 @@
 	unsigned long flags = 0;
 	int poll_next;
 
-	WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
+	WARN_ON_ONCE((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
 
 	/* Make sure ata_sff_qc_issue() does not throw things
 	 * like DMA polling into the workqueue. Notice that
 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
 	 */
-	WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
+	WARN_ON_ONCE(in_wq != ata_hsm_ok_in_wq(ap, qc));
 
 fsm_start:
 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
@@ -1387,7 +1387,7 @@
 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
 			ap->print_id, qc->dev->devno, status);
 
-		WARN_ON(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
+		WARN_ON_ONCE(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
 
 		ap->hsm_task_state = HSM_ST_IDLE;
 
@@ -1423,7 +1423,7 @@
 	int poll_next;
 
 fsm_start:
-	WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
+	WARN_ON_ONCE(ap->hsm_task_state == HSM_ST_IDLE);
 
 	/*
 	 * This is purely heuristic.  This is a fast path.
@@ -1512,7 +1512,7 @@
 		break;
 
 	case ATA_PROT_DMA:
-		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
 
 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
@@ -1564,7 +1564,7 @@
 		break;
 
 	case ATAPI_PROT_DMA:
-		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
 
 		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
@@ -1576,7 +1576,7 @@
 		break;
 
 	default:
-		WARN_ON(1);
+		WARN_ON_ONCE(1);
 		return AC_ERR_SYSTEM;
 	}