Index: sys/cam/ata/ata_da.c
===================================================================
--- sys/cam/ata/ata_da.c
+++ sys/cam/ata/ata_da.c
@@ -1608,7 +1608,7 @@
 			    ada_retry_count,
 			    adadone,
 			    rw_op,
-			    tag_code,
+			    0,
 			    data_ptr,
 			    bp->bio_bcount,
 			    ada_default_timeout*1000);
Index: sys/cam/cam_ccb.h
===================================================================
--- sys/cam/cam_ccb.h
+++ sys/cam/cam_ccb.h
@@ -579,6 +579,7 @@
 } pi_tmflag;
 
 typedef enum {
+	PIM_ATA_EXT	= 0x200,/* ATA requests can understand ata_ext requests */
 	PIM_EXTLUNS	= 0x100,/* 64bit extended LUNs supported */
 	PIM_SCANHILO	= 0x80,	/* Bus scans from high ID to low ID */
 	PIM_NOREMOVE	= 0x40,	/* Removeable devices not included in scan */
@@ -734,15 +735,10 @@
 	u_int8_t   *data_ptr;		/* Ptr to the data buf/SG list */
 	u_int32_t  dxfer_len;		/* Data transfer length */
 	u_int32_t  resid;		/* Transfer residual length: 2's comp */
-	u_int8_t   tag_action;		/* What to do for tag queueing */
-	/*
-	 * The tag action should be either the define below (to send a
-	 * non-tagged transaction) or one of the defined scsi tag messages
-	 * from scsi_message.h.
-	 */
-#define		CAM_TAG_ACTION_NONE	0x00
-	u_int	   tag_id;		/* tag id from initator (target mode) */
-	u_int	   init_id;		/* initiator id of who selected */
+	u_int8_t   ata_flags;		/* Flags for the rest of the buffer */
+#define ATA_FLAG_AUX 0x1
+	uint32_t   aux;
+	uint32_t   unused;
 };
 
 struct ccb_accept_tio {
@@ -1288,7 +1284,7 @@
 static __inline void
 cam_fill_ataio(struct ccb_ataio *ataio, u_int32_t retries,
 	      void (*cbfcnp)(struct cam_periph *, union ccb *),
-	      u_int32_t flags, u_int tag_action,
+	      u_int32_t flags, u_int tag_action __unused,
 	      u_int8_t *data_ptr, u_int32_t dxfer_len,
 	      u_int32_t timeout)
 {
@@ -1299,7 +1295,7 @@
 	ataio->ccb_h.timeout = timeout;
 	ataio->data_ptr = data_ptr;
 	ataio->dxfer_len = dxfer_len;
-	ataio->tag_action = tag_action;
+	ataio->ata_flags = 0;
 }
 
 static __inline void
Index: sys/cam/cam_periph.c
===================================================================
--- sys/cam/cam_periph.c
+++ sys/cam/cam_periph.c
@@ -1116,7 +1116,7 @@
 		} else if (ccb->ccb_h.func_code == XPT_ATA_IO) {
 			devstat_end_transaction(ds,
 					ccb->ataio.dxfer_len - ccb->ataio.resid,
-					ccb->ataio.tag_action & 0x3,
+					0, /* Not used in ATA */
 					((ccb->ccb_h.flags & CAM_DIR_MASK) ==
 					CAM_DIR_NONE) ?  DEVSTAT_NO_DATA : 
 					(ccb->ccb_h.flags & CAM_DIR_OUT) ?
Index: sys/cam/scsi/scsi_pass.c
===================================================================
--- sys/cam/scsi/scsi_pass.c
+++ sys/cam/scsi/scsi_pass.c
@@ -945,7 +945,7 @@
 		case XPT_ATA_IO:
 			devstat_end_transaction(softc->device_stats,
 			    done_ccb->ataio.dxfer_len - done_ccb->ataio.resid,
-			    done_ccb->ataio.tag_action & 0x3,
+			    0, /* Not used in ATA */
 			    ((done_ccb->ccb_h.flags & CAM_DIR_MASK) ==
 			    CAM_DIR_NONE) ? DEVSTAT_NO_DATA : 
 			    (done_ccb->ccb_h.flags & CAM_DIR_OUT) ?
Index: sys/dev/ahci/ahci.c
===================================================================
--- sys/dev/ahci/ahci.c
+++ sys/dev/ahci/ahci.c
@@ -2420,6 +2420,12 @@
 	} else {
 		fis[15] = ccb->ataio.cmd.control;
 	}
+	if (ccb->ataio.flags & ATA_FLAG_AUX) {
+		fis[16] =  ccb->ataio.aux        & 0xff;
+		fis[17] = (ccb->ataio.aux >>  8) & 0xff;
+		fis[18] = (ccb->ataio.aux >> 16) & 0xff;
+		fis[19] = (ccb->ataio.aux >> 24) & 0xff;
+	}
 	return (20);
 }
 
@@ -2674,7 +2680,7 @@
 		if (ch->caps & AHCI_CAP_SPM)
 			cpi->hba_inquiry |= PI_SATAPM;
 		cpi->target_sprt = 0;
-		cpi->hba_misc = PIM_SEQSCAN | PIM_UNMAPPED;
+		cpi->hba_misc = PIM_SEQSCAN | PIM_UNMAPPED | PIM_ATA_EXT;
 		cpi->hba_eng_cnt = 0;
 		if (ch->caps & AHCI_CAP_SPM)
 			cpi->max_target = 15;
Index: sys/dev/mvs/mvs.c
===================================================================
--- sys/dev/mvs/mvs.c
+++ sys/dev/mvs/mvs.c
@@ -2245,6 +2245,11 @@
 		xpt_done(ccb);
 		return (-1);
 	}
+	/*
+	 * We shouldn't see AUXILIARY register requests.
+	 */
+	KASSERT (ccb->ccb_h.func_code != XPT_ATA_IO ||
+	    ((ccb->ataio.ata_flags & ATA_FLAGS_AUX) == 0));
 	return (0);
 }
 
Index: sys/dev/siis/siis.c
===================================================================
--- sys/dev/siis/siis.c
+++ sys/dev/siis/siis.c
@@ -1728,6 +1728,12 @@
 			fis[13] = ccb->ataio.cmd.sector_count_exp;
 		}
 		fis[15] = ATA_A_4BIT;
+		if (ccb->ataio.flags & ATA_FLAG_AUX) {
+			fis[16] =  ccb->ataio.aux        & 0xff;
+			fis[17] = (ccb->ataio.aux >>  8) & 0xff;
+			fis[18] = (ccb->ataio.aux >> 16) & 0xff;
+			fis[19] = (ccb->ataio.aux >> 24) & 0xff;
+		}
 	} else {
 		/* Soft reset. */
 	}
@@ -1946,7 +1952,7 @@
 		cpi->hba_inquiry = PI_SDTR_ABLE | PI_TAG_ABLE;
 		cpi->hba_inquiry |= PI_SATAPM;
 		cpi->target_sprt = 0;
-		cpi->hba_misc = PIM_SEQSCAN | PIM_UNMAPPED;
+		cpi->hba_misc = PIM_SEQSCAN | PIM_UNMAPPED | PIM_ATA_EXT;
 		cpi->hba_eng_cnt = 0;
 		cpi->max_target = 15;
 		cpi->max_lun = 0;