From 8e3f76a9e767e7494c68554c9ea68e3c34327b72 Mon Sep 17 00:00:00 2001
From: Tejun Heo <htejun@gmail.com>
Date: Mon, 15 May 2006 21:03:45 +0900
Subject: [PATCH] --- yaml --- r: 29432 b: refs/heads/master c:
 3dc1d88193b9c65b01b64fb2dc730e486306649f h: refs/heads/master v: v3

---
 [refs]                           |  2 +-
 trunk/drivers/scsi/libata-core.c |  1 +
 trunk/drivers/scsi/libata-scsi.c | 72 +++++++++++++++++++++++++++++++-
 3 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 246cd5616e9f..02b59cedc976 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dedaf2b0365ccec50714fbde0b3215e7e94fa47c
+refs/heads/master: 3dc1d88193b9c65b01b64fb2dc730e486306649f
diff --git a/trunk/drivers/scsi/libata-core.c b/trunk/drivers/scsi/libata-core.c
index eea1fe9c8b79..14ffb5264b65 100644
--- a/trunk/drivers/scsi/libata-core.c
+++ b/trunk/drivers/scsi/libata-core.c
@@ -4416,6 +4416,7 @@ static inline int ata_should_dma_map(struct ata_queued_cmd *qc)
 	struct ata_port *ap = qc->ap;
 
 	switch (qc->tf.protocol) {
+	case ATA_PROT_NCQ:
 	case ATA_PROT_DMA:
 	case ATA_PROT_ATAPI_DMA:
 		return 1;
diff --git a/trunk/drivers/scsi/libata-scsi.c b/trunk/drivers/scsi/libata-scsi.c
index 96517ca021e3..9bef68c7c1de 100644
--- a/trunk/drivers/scsi/libata-scsi.c
+++ b/trunk/drivers/scsi/libata-scsi.c
@@ -1103,7 +1103,36 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *scsicm
 		 */
 		goto nothing_to_do;
 
-	if (dev->flags & ATA_DFLAG_LBA) {
+	if ((dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ) {
+		/* yay, NCQ */
+		if (!lba_48_ok(block, n_block))
+			goto out_of_range;
+
+		tf->protocol = ATA_PROT_NCQ;
+		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
+
+		if (tf->flags & ATA_TFLAG_WRITE)
+			tf->command = ATA_CMD_FPDMA_WRITE;
+		else
+			tf->command = ATA_CMD_FPDMA_READ;
+
+		qc->nsect = n_block;
+
+		tf->nsect = qc->tag << 3;
+		tf->hob_feature = (n_block >> 8) & 0xff;
+		tf->feature = n_block & 0xff;
+
+		tf->hob_lbah = (block >> 40) & 0xff;
+		tf->hob_lbam = (block >> 32) & 0xff;
+		tf->hob_lbal = (block >> 24) & 0xff;
+		tf->lbah = (block >> 16) & 0xff;
+		tf->lbam = (block >> 8) & 0xff;
+		tf->lbal = block & 0xff;
+
+		tf->device = 1 << 6;
+		if (tf->flags & ATA_TFLAG_FUA)
+			tf->device |= 1 << 7;
+	} else if (dev->flags & ATA_DFLAG_LBA) {
 		tf->flags |= ATA_TFLAG_LBA;
 
 		if (lba_28_ok(block, n_block)) {
@@ -1226,6 +1255,39 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 	ata_qc_free(qc);
 }
 
+/**
+ *	ata_scmd_need_defer - Check whether we need to defer scmd
+ *	@dev: ATA device to which the command is addressed
+ *	@is_io: Is the command IO (and thus possibly NCQ)?
+ *
+ *	NCQ and non-NCQ commands cannot run together.  As upper layer
+ *	only knows the queue depth, we are responsible for maintaining
+ *	exclusion.  This function checks whether a new command can be
+ *	issued to @dev.
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host_set lock)
+ *
+ *	RETURNS:
+ *	1 if deferring is needed, 0 otherwise.
+ */
+static int ata_scmd_need_defer(struct ata_device *dev, int is_io)
+{
+	struct ata_port *ap = dev->ap;
+
+	if (!(dev->flags & ATA_DFLAG_NCQ))
+		return 0;
+
+	if (is_io) {
+		if (!ata_tag_valid(ap->active_tag))
+			return 0;
+	} else {
+		if (!ata_tag_valid(ap->active_tag) && !ap->sactive)
+			return 0;
+	}
+	return 1;
+}
+
 /**
  *	ata_scsi_translate - Translate then issue SCSI command to ATA device
  *	@dev: ATA device to which the command is addressed
@@ -1259,9 +1321,13 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 {
 	struct ata_queued_cmd *qc;
 	u8 *scsicmd = cmd->cmnd;
+	int is_io = xlat_func == ata_scsi_rw_xlat;
 
 	VPRINTK("ENTER\n");
 
+	if (unlikely(ata_scmd_need_defer(dev, is_io)))
+		goto defer;
+
 	qc = ata_scsi_qc_new(dev, cmd, done);
 	if (!qc)
 		goto err_mem;
@@ -1308,6 +1374,10 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 	done(cmd);
 	DPRINTK("EXIT - internal\n");
 	return 0;
+
+defer:
+	DPRINTK("EXIT - defer\n");
+	return SCSI_MLQUEUE_DEVICE_BUSY;
 }
 
 /**