Date:	Wed, 22 Apr 2009 05:09:29 -0400
From:	Jeff Garzik <jeff@...zik.org>
To:	linux-ide@...r.kernel.org, linux-scsi@...r.kernel.org
Cc:	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH] libata: rewrite SCSI host scheme to be one per ATA host


Currently, libata creates a Scsi_Host per port.  This was originally
done to leverage SCSI's infrastructure to arbitrate among master/slave
devices, but is not needed for most modern SATA controllers.   And I
_think_ it is not needed for master/slave if done properly, either.

The patch below converts libata such that there is now a 1:1
correspondence between struct Scsi_Host and struct ata_host.  ATA ports
are represented as SCSI layer 'channels', which is more natural.

This patch is an experiment, and not meant for upstream anytime soon.
I just wanted to see what kind of effort would be required to get it
to work.

I was able to successfully boot the following patch on
AHCI/x86-64/Fedora.

It may work with other controllers -- TRY AT YOUR OWN RISK.  It will
probably fail for master/slave configurations, and SAS & PMP also
need looking at.  It yielded this lsscsi output on my AHCI box:

[0:0:0:0]    disk    ATA      ST3500320AS      SD15  /dev/sda
[0:2:0:0]    disk    ATA      G.SKILL 128GB SS 02.1  /dev/sdb
[0:5:0:0]    cd/dvd  PIONEER  BD-ROM  BDC-202  1.04  /dev/sr0

NOT-signed-off-by: me

 drivers/ata/ahci.c            |    4 
 drivers/ata/libata-core.c     |   17 +--
 drivers/ata/libata-eh.c       |   47 ++++++--
 drivers/ata/libata-scsi.c     |  237 +++++++++++++++++++++---------------------
 drivers/ata/libata.h          |    3 
 drivers/scsi/libsas/sas_ata.c |    2 
 include/linux/libata.h        |    9 -
 7 files changed, 184 insertions(+), 135 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 08186ec..b0468a8 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -326,14 +326,18 @@ static ssize_t ahci_activity_store(struct ata_device *dev,
 static void ahci_init_sw_activity(struct ata_link *link);
 
 static struct device_attribute *ahci_shost_attrs[] = {
+#if 0
 	&dev_attr_link_power_management_policy,
 	&dev_attr_em_message_type,
 	&dev_attr_em_message,
+#endif
 	NULL
 };
 
 static struct device_attribute *ahci_sdev_attrs[] = {
+#if 0
 	&dev_attr_sw_activity,
+#endif
 	&dev_attr_unload_heads,
 	NULL
 };
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 17c5d48..71f32dc 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -95,6 +95,7 @@ static void ata_dev_xfermask(struct ata_device *dev);
 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
 
 unsigned int ata_print_id = 1;
+unsigned int ata_host_print_id = 1;
 static struct workqueue_struct *ata_wq;
 
 struct workqueue_struct *ata_aux_wq;
@@ -2308,7 +2309,7 @@ static void ata_dev_config_ncq(struct ata_device *dev,
 		return;
 	}
 	if (ap->flags & ATA_FLAG_NCQ) {
-		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
+		hdepth = min(ap->host->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
 		dev->flags |= ATA_DFLAG_NCQ;
 	}
 
@@ -5635,15 +5636,15 @@ static void ata_host_release(struct device *gendev, void *res)
 		if (!ap)
 			continue;
 
-		if (ap->scsi_host)
-			scsi_host_put(ap->scsi_host);
-
 		kfree(ap->pmp_link);
 		kfree(ap->slave_link);
 		kfree(ap);
 		host->ports[i] = NULL;
 	}
 
+	if (host->scsi_host)
+		scsi_host_put(host->scsi_host);
+
 	dev_set_drvdata(gendev, NULL);
 }
 
@@ -6089,6 +6090,8 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 	for (i = 0; i < host->n_ports; i++)
 		host->ports[i]->print_id = ata_print_id++;
 
+	host->print_id = ata_host_print_id++;
+
 	rc = ata_scsi_add_hosts(host, sht);
 	if (rc)
 		return rc;
@@ -6222,8 +6225,7 @@ static void ata_port_detach(struct ata_port *ap)
 	cancel_rearming_delayed_work(&ap->hotplug_task);
 
  skip_eh:
-	/* remove the associated SCSI host */
-	scsi_remove_host(ap->scsi_host);
+ 	return;
 }
 
 /**
@@ -6242,6 +6244,9 @@ void ata_host_detach(struct ata_host *host)
 	for (i = 0; i < host->n_ports; i++)
 		ata_port_detach(host->ports[i]);
 
+	/* remove the associated SCSI host */
+	scsi_remove_host(host->scsi_host);
+
 	/* the host is dead now, dissociate ACPI */
 	ata_acpi_dissociate(host);
 }
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 0183131..db8a66f 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -466,14 +466,22 @@ static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
  */
 enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 {
-	struct Scsi_Host *host = cmd->device->host;
-	struct ata_port *ap = ata_shost_to_port(host);
+	struct Scsi_Host *shost = cmd->device->host;
+	struct ata_port *ap;
+	struct ata_host *host;
+	struct ata_device *atadev;
 	unsigned long flags;
 	struct ata_queued_cmd *qc;
-	enum blk_eh_timer_return ret;
+	enum blk_eh_timer_return ret = BLK_EH_NOT_HANDLED;
 
 	DPRINTK("ENTER\n");
 
+	host = ata_shost_to_host(shost);
+	atadev = ata_scsi_find_dev(host, cmd->device);
+	if (!atadev)
+		goto out;
+	ap = atadev->link->ap;
+
 	if (ap->ops->error_handler) {
 		ret = BLK_EH_NOT_HANDLED;
 		goto out;
@@ -532,13 +540,12 @@ static void ata_eh_unload(struct ata_port *ap)
  *	RETURNS:
  *	Zero.
  */
-void ata_scsi_error(struct Scsi_Host *host)
+static void __ata_scsi_error(struct Scsi_Host *shost, struct ata_port *ap)
 {
-	struct ata_port *ap = ata_shost_to_port(host);
 	int i;
 	unsigned long flags;
 
-	DPRINTK("ENTER\n");
+	DPRINTK("ENTER, port_no %u\n", ap->port_no);
 
 	/* synchronize with port task */
 	ata_port_flush_task(ap);
@@ -575,7 +582,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 		if (ap->ops->lost_interrupt)
 			ap->ops->lost_interrupt(ap);
 			
-		list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {
+		list_for_each_entry_safe(scmd, tmp, &shost->eh_cmd_q, eh_entry) {
 			struct ata_queued_cmd *qc;
 
 			for (i = 0; i < ATA_MAX_QUEUE; i++) {
@@ -698,7 +705,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 		 * before EH completion, SCSI midlayer will
 		 * re-initiate EH.
 		 */
-		host->host_eh_scheduled = 0;
+		shost->host_eh_scheduled = 0;
 
 		spin_unlock_irqrestore(ap->lock, flags);
 	} else {
@@ -707,7 +714,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 	}
 
 	/* finish or retry handled scmd's and clean up */
-	WARN_ON(host->host_failed || !list_empty(&host->eh_cmd_q));
+	WARN_ON(shost->host_failed || !list_empty(&shost->eh_cmd_q));
 
 	scsi_eh_flush_done_q(&ap->eh_done_q);
 
@@ -733,6 +740,24 @@ void ata_scsi_error(struct Scsi_Host *host)
 	DPRINTK("EXIT\n");
 }
 
+void ata_scsi_error(struct Scsi_Host *shost)
+{
+	struct ata_host *host = ata_shost_to_host(shost);
+	unsigned int i;
+
+	DPRINTK("ENTER\n");
+
+	for (i = 0; i < host->n_ports; i++) {
+		struct ata_port *ap = host->ports[i];
+
+		if (ap->pflags & ATA_PFLAG_EH_PENDING)
+			__ata_scsi_error(shost, ap);
+	}
+
+	DPRINTK("EXIT\n");
+}
+
+
 /**
  *	ata_port_wait_eh - Wait for the currently pending EH to complete
  *	@ap: Port to wait EH for
@@ -761,7 +786,7 @@ void ata_port_wait_eh(struct ata_port *ap)
 	spin_unlock_irqrestore(ap->lock, flags);
 
 	/* make sure SCSI EH is complete */
-	if (scsi_host_in_recovery(ap->scsi_host)) {
+	if (scsi_host_in_recovery(ap->host->scsi_host)) {
 		msleep(10);
 		goto retry;
 	}
@@ -901,7 +926,7 @@ void ata_port_schedule_eh(struct ata_port *ap)
 		return;
 
 	ata_eh_set_pending(ap, 1);
-	scsi_schedule_eh(ap->scsi_host);
+	scsi_schedule_eh(ap->host->scsi_host);
 
 	DPRINTK("port EH scheduled\n");
 }
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 2733b0c..7aa6aa6 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -58,10 +58,8 @@ static u8 ata_scsi_rbuf[ATA_SCSI_RBUF_SIZE];
 
 typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);
 
-static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
+static struct ata_device *__ata_scsi_find_dev(struct ata_host *,
 					const struct scsi_device *scsidev);
-static struct ata_device *ata_scsi_find_dev(struct ata_port *ap,
-					    const struct scsi_device *scsidev);
 static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
 			      unsigned int id, unsigned int lun);
 
@@ -136,6 +134,7 @@ static const char *ata_scsi_lpm_get(enum link_pm policy)
 	return NULL;
 }
 
+#if 0
 static ssize_t ata_scsi_lpm_put(struct device *dev,
 				struct device_attribute *attr,
 				const char *buf, size_t count)
@@ -183,6 +182,7 @@ ata_scsi_lpm_show(struct device *dev, struct device_attribute *attr, char *buf)
 DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
 		ata_scsi_lpm_show, ata_scsi_lpm_put);
 EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);
+#endif
 
 static ssize_t ata_scsi_park_show(struct device *device,
 				  struct device_attribute *attr, char *buf)
@@ -190,19 +190,21 @@ static ssize_t ata_scsi_park_show(struct device *device,
 	struct scsi_device *sdev = to_scsi_device(device);
 	struct ata_port *ap;
 	struct ata_link *link;
+	struct ata_host *host;
 	struct ata_device *dev;
 	unsigned long flags, now;
 	unsigned int uninitialized_var(msecs);
 	int rc = 0;
 
-	ap = ata_shost_to_port(sdev->host);
+	host = ata_shost_to_host(sdev->host);
 
-	spin_lock_irqsave(ap->lock, flags);
-	dev = ata_scsi_find_dev(ap, sdev);
+	spin_lock_irqsave(&host->lock, flags);
+	dev = ata_scsi_find_dev(host, sdev);
 	if (!dev) {
 		rc = -ENODEV;
 		goto unlock;
 	}
+	ap = dev->link->ap;
 	if (dev->flags & ATA_DFLAG_NO_UNLOAD) {
 		rc = -EOPNOTSUPP;
 		goto unlock;
@@ -218,7 +220,7 @@ static ssize_t ata_scsi_park_show(struct device *device,
 		msecs = 0;
 
 unlock:
-	spin_unlock_irq(ap->lock);
+	spin_unlock_irq(&host->lock);
 
 	return rc ? rc : snprintf(buf, 20, "%u\n", msecs);
 }
@@ -230,6 +232,7 @@ static ssize_t ata_scsi_park_store(struct device *device,
 	struct scsi_device *sdev = to_scsi_device(device);
 	struct ata_port *ap;
 	struct ata_device *dev;
+	struct ata_host *host;
 	long int input;
 	unsigned long flags;
 	int rc;
@@ -242,14 +245,15 @@ static ssize_t ata_scsi_park_store(struct device *device,
 		input = ATA_TMOUT_MAX_PARK;
 	}
 
-	ap = ata_shost_to_port(sdev->host);
+	host = ata_shost_to_host(sdev->host);
 
-	spin_lock_irqsave(ap->lock, flags);
-	dev = ata_scsi_find_dev(ap, sdev);
+	spin_lock_irqsave(&host->lock, flags);
+	dev = ata_scsi_find_dev(host, sdev);
 	if (unlikely(!dev)) {
 		rc = -ENODEV;
 		goto unlock;
 	}
+	ap = dev->link->ap;
 	if (dev->class != ATA_DEV_ATA) {
 		rc = -EOPNOTSUPP;
 		goto unlock;
@@ -276,7 +280,7 @@ static ssize_t ata_scsi_park_store(struct device *device,
 		}
 	}
 unlock:
-	spin_unlock_irqrestore(ap->lock, flags);
+	spin_unlock_irqrestore(&host->lock, flags);
 
 	return rc ? rc : len;
 }
@@ -291,6 +295,7 @@ static void ata_scsi_set_sense(struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq)
 	scsi_build_sense_buffer(0, cmd->sense_buffer, sk, asc, ascq);
 }
 
+#if 0
 static ssize_t
 ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t count)
@@ -335,8 +340,9 @@ ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
 		char *buf)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
-	struct ata_port *ap = ata_shost_to_port(sdev->host);
-	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+	struct ata_host *host = ata_shost_to_host(sdev->host);
+	struct ata_device *atadev = ata_scsi_find_dev(host, sdev);
+	struct ata_port *ap = atadev->ap;
 
 	if (ap->ops->sw_activity_show && (ap->flags & ATA_FLAG_SW_ACTIVITY))
 		return ap->ops->sw_activity_show(atadev, buf);
@@ -348,8 +354,9 @@ ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
 	const char *buf, size_t count)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
-	struct ata_port *ap = ata_shost_to_port(sdev->host);
-	struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+	struct ata_host *host = ata_shost_to_host(sdev->host);
+	struct ata_device *atadev = ata_scsi_find_dev(host, sdev);
+	struct ata_port *ap = atadev->ap;
 	enum sw_activity val;
 	int rc;
 
@@ -369,6 +376,7 @@ ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
 DEVICE_ATTR(sw_activity, S_IWUGO | S_IRUGO, ata_scsi_activity_show,
 			ata_scsi_activity_store);
 EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
+#endif
 
 struct device_attribute *ata_common_sdev_attrs[] = {
 	&dev_attr_unload_heads,
@@ -425,10 +433,10 @@ int ata_std_bios_param(struct scsi_device *sdev, struct block_device *bdev,
  *	RETURNS:
  *	Zero on success, negative errno on error.
  */
-static int ata_get_identity(struct ata_port *ap, struct scsi_device *sdev,
+static int ata_get_identity(struct ata_host *host, struct scsi_device *sdev,
 			    void __user *arg)
 {
-	struct ata_device *dev = ata_scsi_find_dev(ap, sdev);
+	struct ata_device *dev = ata_scsi_find_dev(host, sdev);
 	u16 __user *dst = arg;
 	char buf[40];
 
@@ -656,11 +664,18 @@ static int ata_ioc32(struct ata_port *ap)
 	return 0;
 }
 
-int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
+int ata_sas_scsi_ioctl(struct ata_host *host, struct scsi_device *scsidev,
 		     int cmd, void __user *arg)
 {
 	int val = -EINVAL, rc = -EINVAL;
 	unsigned long flags;
+	struct ata_port *ap;
+	struct ata_device *atadev;
+
+	atadev = ata_scsi_find_dev(host, scsidev);
+	if (!atadev)
+		return -ENOENT;
+	ap = atadev->link->ap;
 
 	switch (cmd) {
 	case ATA_IOC_GET_IO32:
@@ -688,7 +703,7 @@ int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
 		return rc;
 
 	case HDIO_GET_IDENTITY:
-		return ata_get_identity(ap, scsidev, arg);
+		return ata_get_identity(host, scsidev, arg);
 
 	case HDIO_DRIVE_CMD:
 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
@@ -711,7 +726,7 @@ EXPORT_SYMBOL_GPL(ata_sas_scsi_ioctl);
 
 int ata_scsi_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg)
 {
-	return ata_sas_scsi_ioctl(ata_shost_to_port(scsidev->host),
+	return ata_sas_scsi_ioctl(ata_shost_to_host(scsidev->host),
 				scsidev, cmd, arg);
 }
 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
@@ -1157,8 +1172,8 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 
 int ata_scsi_slave_config(struct scsi_device *sdev)
 {
-	struct ata_port *ap = ata_shost_to_port(sdev->host);
-	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
+	struct ata_host *host = ata_shost_to_host(sdev->host);
+	struct ata_device *dev = __ata_scsi_find_dev(host, sdev);
 	int rc = 0;
 
 	ata_scsi_sdev_config(sdev);
@@ -1185,27 +1200,34 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
  */
 void ata_scsi_slave_destroy(struct scsi_device *sdev)
 {
-	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_host *host = ata_shost_to_host(sdev->host);
 	struct request_queue *q = sdev->request_queue;
 	unsigned long flags;
 	struct ata_device *dev;
+	bool new_eh = true;
 
-	if (!ap->ops->error_handler)
-		return;
-
-	spin_lock_irqsave(ap->lock, flags);
-	dev = __ata_scsi_find_dev(ap, sdev);
+	spin_lock_irqsave(&host->lock, flags);
+	dev = __ata_scsi_find_dev(host, sdev);
 	if (dev && dev->sdev) {
+		struct ata_port *ap = dev->link->ap;
+
+		if (!ap->ops->error_handler)
+			new_eh = false;
+
+		else {
 		/* SCSI device already in CANCEL state, no need to offline it */
 		dev->sdev = NULL;
 		dev->flags |= ATA_DFLAG_DETACH;
 		ata_port_schedule_eh(ap);
+		}
 	}
-	spin_unlock_irqrestore(ap->lock, flags);
+	spin_unlock_irqrestore(&host->lock, flags);
 
-	kfree(q->dma_drain_buffer);
-	q->dma_drain_buffer = NULL;
-	q->dma_drain_size = 0;
+	if (new_eh) {
+		kfree(q->dma_drain_buffer);
+		q->dma_drain_buffer = NULL;
+		q->dma_drain_size = 0;
+	}
 }
 
 /**
@@ -1225,25 +1247,25 @@ void ata_scsi_slave_destroy(struct scsi_device *sdev)
  */
 int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
 {
-	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_host *host = ata_shost_to_host(sdev->host);
 	struct ata_device *dev;
 	unsigned long flags;
 
 	if (queue_depth < 1 || queue_depth == sdev->queue_depth)
 		return sdev->queue_depth;
 
-	dev = ata_scsi_find_dev(ap, sdev);
+	dev = ata_scsi_find_dev(host, sdev);
 	if (!dev || !ata_dev_enabled(dev))
 		return sdev->queue_depth;
 
 	/* NCQ enabled? */
-	spin_lock_irqsave(ap->lock, flags);
+	spin_lock_irqsave(&host->lock, flags);
 	dev->flags &= ~ATA_DFLAG_NCQ_OFF;
 	if (queue_depth == 1 || !ata_ncq_enabled(dev)) {
 		dev->flags |= ATA_DFLAG_NCQ_OFF;
 		queue_depth = 1;
 	}
-	spin_unlock_irqrestore(ap->lock, flags);
+	spin_unlock_irqrestore(&host->lock, flags);
 
 	/* limit and apply queue depth */
 	queue_depth = min(queue_depth, sdev->host->can_queue);
@@ -2690,21 +2712,20 @@ static struct ata_device *ata_find_dev(struct ata_port *ap, int devno)
 	return NULL;
 }
 
-static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
+static struct ata_device *__ata_scsi_find_dev(struct ata_host *host,
 					      const struct scsi_device *scsidev)
 {
 	int devno;
+	struct ata_port *ap;
 
-	/* skip commands not addressed to targets we simulate */
-	if (!sata_pmp_attached(ap)) {
-		if (unlikely(scsidev->channel || scsidev->lun))
-			return NULL;
-		devno = scsidev->id;
-	} else {
-		if (unlikely(scsidev->id || scsidev->lun))
-			return NULL;
-		devno = scsidev->channel;
-	}
+	if (scsidev->channel > host->n_ports)
+		return NULL;
+	
+	ap = host->ports[scsidev->channel];
+	if (ata_port_is_dummy(ap))
+		return NULL;
+
+	devno = scsidev->id;
 
 	return ata_find_dev(ap, devno);
 }
@@ -2725,10 +2746,10 @@ static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
  *	RETURNS:
  *	Associated ATA device, or %NULL if not found.
  */
-static struct ata_device *
-ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev)
+struct ata_device *
+ata_scsi_find_dev(struct ata_host *host, const struct scsi_device *scsidev)
 {
-	struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
+	struct ata_device *dev = __ata_scsi_find_dev(host, scsidev);
 
 	if (unlikely(!dev || !ata_dev_enabled(dev)))
 		return NULL;
@@ -2983,15 +3004,13 @@ static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
  *	Prints the contents of a SCSI command via printk().
  */
 
-static inline void ata_scsi_dump_cdb(struct ata_port *ap,
-				     struct scsi_cmnd *cmd)
+static inline void ata_scsi_dump_cdb(struct scsi_cmnd *cmd)
 {
 #ifdef ATA_DEBUG
 	struct scsi_device *scsidev = cmd->device;
 	u8 *scsicmd = cmd->cmnd;
 
-	DPRINTK("CDB (%u:%d,%d,%d) %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
-		ap->print_id,
+	DPRINTK("CDB (%d,%d,%d) %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
 		scsidev->channel, scsidev->id, scsidev->lun,
 		scsicmd[0], scsicmd[1], scsicmd[2], scsicmd[3],
 		scsicmd[4], scsicmd[5], scsicmd[6], scsicmd[7],
@@ -3069,20 +3088,20 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
  */
 int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 {
-	struct ata_port *ap;
 	struct ata_device *dev;
+	struct ata_host *host;
 	struct scsi_device *scsidev = cmd->device;
 	struct Scsi_Host *shost = scsidev->host;
 	int rc = 0;
 
-	ap = ata_shost_to_port(shost);
+	host = ata_shost_to_host(shost);
 
 	spin_unlock(shost->host_lock);
-	spin_lock(ap->lock);
+	spin_lock(&host->lock);
 
-	ata_scsi_dump_cdb(ap, cmd);
+	ata_scsi_dump_cdb(cmd);
 
-	dev = ata_scsi_find_dev(ap, scsidev);
+	dev = ata_scsi_find_dev(host, scsidev);
 	if (likely(dev))
 		rc = __ata_scsi_queuecmd(cmd, done, dev);
 	else {
@@ -3090,7 +3109,7 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 		done(cmd);
 	}
 
-	spin_unlock(ap->lock);
+	spin_unlock(&host->lock);
 	spin_lock(shost->host_lock);
 	return rc;
 }
@@ -3217,56 +3236,43 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd,
 
 int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
 {
-	int i, rc;
-
-	for (i = 0; i < host->n_ports; i++) {
-		struct ata_port *ap = host->ports[i];
-		struct Scsi_Host *shost;
+	int rc;
+	struct Scsi_Host *shost;
 
-		rc = -ENOMEM;
-		shost = scsi_host_alloc(sht, sizeof(struct ata_port *));
-		if (!shost)
-			goto err_alloc;
+	shost = scsi_host_alloc(sht, sizeof(struct ata_host *));
+	if (!shost)
+		return -ENOMEM;
 
-		*(struct ata_port **)&shost->hostdata[0] = ap;
-		ap->scsi_host = shost;
+	*(struct ata_host **)&shost->hostdata[0] = host;
+	host->scsi_host = shost;
 
-		shost->transportt = &ata_scsi_transport_template;
-		shost->unique_id = ap->print_id;
-		shost->max_id = 16;
-		shost->max_lun = 1;
-		shost->max_channel = 1;
-		shost->max_cmd_len = 16;
+	shost->transportt = &ata_scsi_transport_template;
+	shost->unique_id = host->print_id;
+	shost->max_id = 32;
+	shost->max_lun = 1;
+	shost->max_channel = 32;
+	shost->max_cmd_len = 16;
 
-		/* Schedule policy is determined by ->qc_defer()
-		 * callback and it needs to see every deferred qc.
-		 * Set host_blocked to 1 to prevent SCSI midlayer from
-		 * automatically deferring requests.
-		 */
-		shost->max_host_blocked = 1;
+	/* Schedule policy is determined by ->qc_defer()
+	 * callback and it needs to see every deferred qc.
+	 * Set host_blocked to 1 to prevent SCSI midlayer from
+	 * automatically deferring requests.
+	 */
+	shost->max_host_blocked = 1;
 
-		rc = scsi_add_host(ap->scsi_host, ap->host->dev);
-		if (rc)
-			goto err_add;
+	rc = scsi_add_host(shost, host->dev);
+	if (rc) {
+		scsi_host_put(shost);
+		return rc;
 	}
 
 	return 0;
-
- err_add:
-	scsi_host_put(host->ports[i]->scsi_host);
- err_alloc:
-	while (--i >= 0) {
-		struct Scsi_Host *shost = host->ports[i]->scsi_host;
-
-		scsi_remove_host(shost);
-		scsi_host_put(shost);
-	}
-	return rc;
 }
 
 void ata_scsi_scan_host(struct ata_port *ap, int sync)
 {
 	int tries = 5;
+	struct ata_host *host = ap->host;
 	struct ata_device *last_failed_dev = NULL;
 	struct ata_link *link;
 	struct ata_device *dev;
@@ -3278,7 +3284,7 @@ void ata_scsi_scan_host(struct ata_port *ap, int sync)
 	ata_for_each_link(link, ap, EDGE) {
 		ata_for_each_dev(dev, link, ENABLED) {
 			struct scsi_device *sdev;
-			int channel = 0, id = 0;
+			int id = 0;
 
 			if (dev->sdev)
 				continue;
@@ -3286,9 +3292,10 @@ void ata_scsi_scan_host(struct ata_port *ap, int sync)
 			if (ata_is_host_link(link))
 				id = dev->devno;
 			else
-				channel = link->pmp;
+				id = link->pmp;
 
-			sdev = __scsi_add_device(ap->scsi_host, channel, id, 0,
+			sdev = __scsi_add_device(host->scsi_host,
+						 ap->port_no, id, 0,
 						 NULL);
 			if (!IS_ERR(sdev)) {
 				dev->sdev = sdev;
@@ -3376,6 +3383,7 @@ int ata_scsi_offline_dev(struct ata_device *dev)
 static void ata_scsi_remove_dev(struct ata_device *dev)
 {
 	struct ata_port *ap = dev->link->ap;
+	struct ata_host *host = ap->host;
 	struct scsi_device *sdev;
 	unsigned long flags;
 
@@ -3385,7 +3393,7 @@ static void ata_scsi_remove_dev(struct ata_device *dev)
 	 * be removed if there is __scsi_device_get() interface which
 	 * increments reference counts regardless of device state.
 	 */
-	mutex_lock(&ap->scsi_host->scan_mutex);
+	mutex_lock(&host->scsi_host->scan_mutex);
 	spin_lock_irqsave(ap->lock, flags);
 
 	/* clearing dev->sdev is protected by host lock */
@@ -3411,7 +3419,7 @@ static void ata_scsi_remove_dev(struct ata_device *dev)
 	}
 
 	spin_unlock_irqrestore(ap->lock, flags);
-	mutex_unlock(&ap->scsi_host->scan_mutex);
+	mutex_unlock(&host->scsi_host->scan_mutex);
 
 	if (sdev) {
 		ata_dev_printk(dev, KERN_INFO, "detaching (SCSI %s)\n",
@@ -3517,25 +3525,28 @@ void ata_scsi_hotplug(struct work_struct *work)
 static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
 			      unsigned int id, unsigned int lun)
 {
-	struct ata_port *ap = ata_shost_to_port(shost);
+	struct ata_port *ap;
+	struct ata_host *host = ata_shost_to_host(shost);
 	unsigned long flags;
 	int devno, rc = 0;
 
+	if (channel == SCAN_WILD_CARD)
+		ap = host->ports[0];
+	else {
+		if (channel > host->n_ports)
+			return -EINVAL;
+		ap = host->ports[channel];
+	}
+
 	if (!ap->ops->error_handler)
 		return -EOPNOTSUPP;
 
 	if (lun != SCAN_WILD_CARD && lun)
 		return -EINVAL;
 
-	if (!sata_pmp_attached(ap)) {
-		if (channel != SCAN_WILD_CARD && channel)
-			return -EINVAL;
-		devno = id;
-	} else {
-		if (id != SCAN_WILD_CARD && id)
-			return -EINVAL;
-		devno = channel;
-	}
+	if (id != SCAN_WILD_CARD && id)
+		return -EINVAL;
+	devno = id;
 
 	spin_lock_irqsave(ap->lock, flags);
 
@@ -3749,7 +3760,7 @@ int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
 {
 	int rc = 0;
 
-	ata_scsi_dump_cdb(ap, cmd);
+	ata_scsi_dump_cdb(cmd);
 
 	if (likely(ata_dev_enabled(ap->link.device)))
 		rc = __ata_scsi_queuecmd(cmd, done, ap->link.device);
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 89a1e00..af890b4 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -205,4 +205,7 @@ extern u8 ata_irq_on(struct ata_port *ap);
 extern void ata_pio_task(struct work_struct *work);
 #endif /* CONFIG_ATA_SFF */
 
+struct ata_device *
+ata_scsi_find_dev(struct ata_host *host, const struct scsi_device *scsidev);
+
 #endif /* __LIBATA_H__ */
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index e155011..758df0b 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -375,6 +375,7 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev,
 		      ha->dev,
 		      sata_port_info.flags,
 		      &sas_sata_ops);
+	found_dev->sata_dev.ata_host.scsi_host = shost;
 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
 				&sata_port_info,
 				shost);
@@ -385,7 +386,6 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev,
 
 	ap->private_data = found_dev;
 	ap->cbl = ATA_CBL_SATA;
-	ap->scsi_host = shost;
 	found_dev->sata_dev.ap = ap;
 
 	return 0;
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3d501db..2ea4dce 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -507,10 +507,12 @@ struct ata_ioports {
 #endif /* CONFIG_ATA_SFF */
 
 struct ata_host {
+	struct Scsi_Host	*scsi_host; /* our co-allocated scsi host */
 	spinlock_t		lock;
 	struct device 		*dev;
 	void __iomem * const	*iomap;
 	unsigned int		n_ports;
+	unsigned int		print_id; /* user visible unique host ID */
 	void			*private_data;
 	struct ata_port_operations *ops;
 	unsigned long		flags;
@@ -690,7 +692,6 @@ struct ata_link {
 };
 
 struct ata_port {
-	struct Scsi_Host	*scsi_host; /* our co-allocated scsi host */
 	struct ata_port_operations *ops;
 	spinlock_t		*lock;
 	/* Flags owned by the EH context. Only EH should touch these once the
@@ -947,7 +948,7 @@ extern void ata_host_init(struct ata_host *, struct device *,
 extern int ata_scsi_detect(struct scsi_host_template *sht);
 extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
 extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
-extern int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *dev,
+extern int ata_sas_scsi_ioctl(struct ata_host *, struct scsi_device *dev,
 			    int cmd, void __user *arg);
 extern void ata_sas_port_destroy(struct ata_port *);
 extern struct ata_port *ata_sas_port_alloc(struct ata_host *,
@@ -1472,9 +1473,9 @@ static inline unsigned int __ac_err_mask(u8 status)
 	return mask;
 }
 
-static inline struct ata_port *ata_shost_to_port(struct Scsi_Host *host)
+static inline struct ata_host *ata_shost_to_host(struct Scsi_Host *host)
 {
-	return *(struct ata_port **)&host->hostdata[0];
+	return *(struct ata_host **)&host->hostdata[0];
 }
 
 static inline int ata_check_ready(u8 status)

View attachment "dmesg.txt" of type "text/plain" (43768 bytes)

Powered by blists - more mailing lists