[PATCH 1/2] Add SATA support to libsas

[PATCH 1/2] Add SATA support to libsas

[Darrick J. Wong]

Hook the scsi_host_template functions in libsas to delegate
functionality to libata when appropriate.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index b0705ee..76bbb9f 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -255,6 +255,7 @@ static int sas_get_port_device(struct as
 
 	switch (dev->dev_type) {
 	case SAS_END_DEV:
+	case SATA_DEV:
 		rphy = sas_end_device_alloc(port->port);
 		break;
 	case EDGE_DEV:
@@ -265,7 +266,6 @@ static int sas_get_port_device(struct as
 		rphy = sas_expander_alloc(port->port,
 					  SAS_FANOUT_EXPANDER_DEVICE);
 		break;
-	case SATA_DEV:
 	default:
 		printk("ERROR: Unidentified device type %d\n", dev->dev_type);
 		rphy = NULL;
@@ -398,6 +398,15 @@ static void sas_sata_propagate_sas_addr(
 	spin_unlock_irqrestore(&port->phy_list_lock, flags);
 }
 
+static inline void sas_mark_dev_sata(struct domain_device *dev)
+{
+	dev->rphy->identify = dev->port->phy->identify;
+	dev->rphy->identify.initiator_port_protocols = SAS_PROTOCOL_SATA;
+	dev->rphy->identify.target_port_protocols = SAS_PROTOCOL_SATA;
+	dev->rphy->identify.device_type = SAS_END_DEVICE;
+	memcpy(&dev->rphy->identify.sas_address, dev->sas_addr, SAS_ADDR_SIZE);
+}
+
 #define ATA_IDENTIFY_DEV         0xEC
 #define ATA_IDENTIFY_PACKET_DEV  0xA1
 #define ATA_SET_FEATURES         0xEF
@@ -480,7 +489,14 @@ cont1:
 	   present.
 	sas_satl_register_dev(dev);
 	*/
-	return 0;
+	
+	sas_mark_dev_sata(dev);
+
+	res = sas_rphy_add(dev->rphy);
+	if (res)
+		goto out_err;
+
+	return res;
 out_err:
 	dev->sata_dev.identify_packet_device = NULL;
 	dev->sata_dev.identify_device = NULL;
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index a0d5133..38893a7 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -36,6 +36,7 @@
 #include <linux/err.h>
 #include <linux/blkdev.h>
 #include <linux/scatterlist.h>
+#include <linux/libata.h>
 
 /* ---------- SCSI Host glue ---------- */
 
@@ -185,6 +186,11 @@ static int sas_queue_up(struct sas_task 
 	return 0;
 }
 
+static inline int dev_is_sata(struct domain_device *dev)
+{
+	return (dev->rphy->identify.target_port_protocols & SAS_PROTOCOL_SATA);
+}
+
 /**
  * sas_queuecommand -- Enqueue a command for processing
  * @parameters: See SCSI Core documentation
@@ -206,6 +212,12 @@ int sas_queuecommand(struct scsi_cmnd *c
 		struct sas_ha_struct *sas_ha = dev->port->ha;
 		struct sas_task *task;
 
+		if (dev_is_sata(dev)) {
+			res = ata_sas_queuecmd(cmd, scsi_done,
+					       dev->sata_dev.ap);
+			goto out;
+		}
+
 		res = -ENOMEM;
 		task = sas_create_task(cmd, dev, GFP_ATOMIC);
 		if (!task)
@@ -529,7 +541,279 @@ enum scsi_eh_timer_return sas_scsi_timed
 	return EH_NOT_HANDLED;
 }
 
-int sas_target_alloc(struct scsi_target *starget)
+static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
+{
+	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */
+
+	/* transport error */
+	if (ts->resp == SAS_TASK_UNDELIVERED)
+		return AC_ERR_ATA_BUS;
+	
+	/* ts->resp == SAS_TASK_COMPLETE */
+	/* task delivered, what happened afterwards? */
+	switch (ts->stat) {
+		case SAS_DEV_NO_RESPONSE:
+			return AC_ERR_TIMEOUT;
+
+		case SAS_INTERRUPTED:
+		case SAS_PHY_DOWN:
+		case SAS_NAK_R_ERR:
+			return AC_ERR_ATA_BUS;
+
+
+		case SAS_DATA_UNDERRUN:
+			/*
+			 * Some programs that use the taskfile interface
+			 * (smartctl in particular) can cause underrun
+			 * problems.  Ignore these errors, perhaps at our
+			 * peril.
+			 */
+			return 0;
+
+		case SAS_DATA_OVERRUN:
+		case SAS_QUEUE_FULL:
+		case SAS_DEVICE_UNKNOWN:
+		case SAS_SG_ERR:
+			return AC_ERR_INVALID;
+
+		case SAM_CHECK_COND:
+		case SAS_OPEN_TO:
+		case SAS_OPEN_REJECT:
+		case SAS_PROTO_RESPONSE:
+			SAS_DPRINTK("%s: Saw error %d.  What to do?\n",
+				    __FUNCTION__, ts->stat);
+			return AC_ERR_OTHER;
+
+		case SAS_ABORTED_TASK:
+			return AC_ERR_DEV;
+
+		default:
+			return 0;
+	}
+}
+
+static void sas_ata_task_done(struct sas_task *task)
+{
+	struct ata_queued_cmd *qc = task->uldd_task;
+	struct domain_device *dev = qc->ap->private_data;
+	struct task_status_struct *stat = &task->task_status;
+	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
+	enum ata_completion_errors ac;
+
+	ac = sas_to_ata_err(stat);
+	if (ac) {
+		SAS_DPRINTK("%s: SAS error %x\n", __FUNCTION__, stat->stat);
+		/* We saw a SAS error. Send a vague error. */
+		qc->err_mask = ac;
+		dev->sata_dev.tf.feature = 0x04; /* status err */
+		dev->sata_dev.tf.command = ATA_ERR;
+		goto end;
+	}
+
+	ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
+	qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
+	dev->sata_dev.sstatus = resp->sstatus;
+	dev->sata_dev.serror = resp->serror;
+	dev->sata_dev.scontrol = resp->scontrol;
+	dev->sata_dev.ap->sactive = resp->sactive;
+end:
+	ata_qc_complete(qc);
+	list_del_init(&task->list);
+	sas_free_task(task);
+}
+
+int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
+{
+	struct domain_device *dev = sdev_to_domain_dev(sdev);
+
+	if (dev_is_sata(dev))
+		return ata_scsi_ioctl(sdev, cmd, arg);
+	
+	return -EINVAL;
+}
+
+static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
+{
+	int res = -ENOMEM;
+	struct sas_task *task;
+	struct domain_device *dev = qc->ap->private_data;
+	struct sas_ha_struct *sas_ha = dev->port->ha;
+	struct Scsi_Host *host = sas_ha->core.shost;
+	struct sas_internal *i = to_sas_internal(host->transportt);
+	struct scatterlist *sg;
+	unsigned int num = 0;
+	unsigned int xfer = 0;
+
+	task = sas_alloc_task(GFP_ATOMIC);
+	if (!task)
+		goto out;
+	task->dev = dev;
+	task->task_proto = SAS_PROTOCOL_STP;
+	task->task_done = sas_ata_task_done;
+
+	ata_tf_to_fis(&qc->tf, (u8*)&task->ata_task.fis, 0);
+	task->uldd_task = qc;
+	if (is_atapi_taskfile(&qc->tf)) {
+		memcpy(task->ata_task.atapi_packet, qc->cdb, ATAPI_CDB_LEN);
+		task->total_xfer_len = qc->nbytes + qc->pad_len;
+		task->num_scatter = qc->pad_len ? qc->n_elem + 1 : qc->n_elem;
+	} else {
+		ata_for_each_sg(sg, qc) {
+			num++;
+			xfer += sg->length;
+		}
+
+		task->total_xfer_len = xfer;
+		task->num_scatter = num;
+	}
+
+	task->data_dir = qc->dma_dir;
+	task->scatter = qc->__sg;
+	task->ata_task.retry_count = 1;
+	task->task_state_flags = SAS_TASK_STATE_PENDING;
+
+	if (qc->tf.protocol == ATA_PROT_DMA)
+		task->ata_task.dma_xfer = 1;
+
+	if (sas_ha->lldd_max_execute_num < 2)
+		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
+	else
+		res = sas_queue_up(task);
+
+	/* Examine */
+	if (res) {
+		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
+
+		sas_free_task(task);
+		if (res == -SAS_QUEUE_FULL)
+			return -ENOMEM;
+	}
+
+out:
+	return res;
+}
+
+static u8 sas_ata_check_status(struct ata_port *ap)
+{
+	struct domain_device *dev = ap->private_data;
+	return dev->sata_dev.tf.command;
+}
+
+static void sas_ata_phy_reset(struct ata_port *ap)
+{
+	struct domain_device *dev = ap->private_data;
+	struct sas_internal *i =
+		to_sas_internal(dev->port->ha->core.shost->transportt);
+	int res = 0;
+
+	if (i->dft->lldd_I_T_nexus_reset)
+		res = i->dft->lldd_I_T_nexus_reset(dev);
+
+	if (res)
+		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __FUNCTION__);
+
+	switch (dev->sata_dev.command_set) {
+		case ATA_COMMAND_SET:
+			SAS_DPRINTK("%s: Found ATA device.\n", __FUNCTION__);
+			ap->device[0].class = ATA_DEV_ATA;
+			break;
+		case ATAPI_COMMAND_SET:
+			SAS_DPRINTK("%s: Found ATAPI device.\n", __FUNCTION__);
+			ap->device[0].class = ATA_DEV_ATAPI;
+			break;
+		default:
+			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
+				    __FUNCTION__,
+				    dev->sata_dev.command_set);
+			ap->device[0].class = ATA_DEV_ATA;
+			break;
+	}
+
+	ap->cbl = ATA_CBL_SATA;
+}
+
+static void sas_ata_post_internal(struct ata_queued_cmd *qc)
+{
+	if (qc->flags & ATA_QCFLAG_FAILED)
+		qc->err_mask |= AC_ERR_OTHER;
+
+	if (qc->err_mask)
+		SAS_DPRINTK("%s: Failure; reset phy!\n", __FUNCTION__);
+}
+
+static void sas_ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
+{
+	struct domain_device *dev = ap->private_data;
+	memcpy(tf, &dev->sata_dev.tf, sizeof (*tf));
+}
+
+static void sas_ata_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
+			      u32 val)
+{
+	struct domain_device *dev = ap->private_data;
+
+	SAS_DPRINTK("STUB %s\n", __FUNCTION__);
+	switch (sc_reg_in) {
+		case SCR_STATUS:
+			dev->sata_dev.sstatus = val;
+			break;
+		case SCR_CONTROL:
+			dev->sata_dev.scontrol = val;
+			break;
+		case SCR_ERROR:
+			dev->sata_dev.serror = val;
+			break;
+		case SCR_ACTIVE:
+			dev->sata_dev.ap->sactive = val;
+			break;
+	}
+}
+
+static u32 sas_ata_scr_read(struct ata_port *ap, unsigned int sc_reg_in)
+{
+	struct domain_device *dev = ap->private_data;
+
+	SAS_DPRINTK("STUB %s\n", __FUNCTION__);
+	switch (sc_reg_in) {
+		case SCR_STATUS:
+			return dev->sata_dev.sstatus;
+		case SCR_CONTROL:
+			return dev->sata_dev.scontrol;
+		case SCR_ERROR:
+			return dev->sata_dev.serror;
+		case SCR_ACTIVE:
+			return dev->sata_dev.ap->sactive;
+		default:
+			return 0xffffffffU;
+	}
+}
+
+static struct ata_port_operations sas_sata_ops = {
+	.port_disable		= ata_port_disable,
+	.check_status		= sas_ata_check_status,
+	.check_altstatus	= sas_ata_check_status,
+	.dev_select		= ata_noop_dev_select,
+	.phy_reset		= sas_ata_phy_reset,
+	.post_internal_cmd	= sas_ata_post_internal,
+	.tf_read		= sas_ata_tf_read,
+	.qc_prep		= ata_noop_qc_prep,
+	.qc_issue		= sas_ata_qc_issue,
+	.port_start		= ata_sas_port_start,
+	.port_stop		= ata_sas_port_stop,
+	.scr_read		= sas_ata_scr_read,
+	.scr_write		= sas_ata_scr_write
+};
+
+static struct ata_port_info sata_port_info = {
+	.host_flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
+		      ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA,
+	.pio_mask = 0x1f, /* PIO0-4 */
+	.mwdma_mask = 0x07, /* MWDMA0-2 */
+	.udma_mask = ATA_UDMA6,
+	.port_ops = &sas_sata_ops
+};
+
+static inline struct domain_device *sas_find_dev(struct scsi_target *starget)
 {
 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
@@ -554,9 +838,39 @@ int sas_target_alloc(struct scsi_target 
 	}
  found:
 	spin_unlock(&ha->phy_port_lock);
+
+	return found_dev;
+}
+
+int sas_target_alloc(struct scsi_target *starget)
+{
+	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
+	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
+	struct domain_device *found_dev = sas_find_dev(starget);
+
 	if (!found_dev)
 		return -ENODEV;
 
+	if (dev_is_sata(found_dev)) {
+		struct ata_port *ap;
+
+		ata_host_set_init(&found_dev->sata_dev.ata_host_set,
+				  &ha->pcidev->dev,
+				  sata_port_info.host_flags,
+				  &sas_sata_ops);
+		ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host_set,
+					&sata_port_info,
+					shost);
+		if (!ap) {
+			SAS_DPRINTK("ata_sas_port_alloc failed.\n");
+			return -ENODEV;
+		}
+
+		ap->private_data = found_dev;
+		ap->cbl = ATA_CBL_SATA;
+		found_dev->sata_dev.ap = ap;
+	}
+
 	starget->hostdata = found_dev;
 	return 0;
 }
@@ -571,6 +885,11 @@ int sas_slave_configure(struct scsi_devi
 
 	BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);
 
+	if (dev_is_sata(dev)) {
+		ata_sas_slave_configure(scsi_dev, dev->sata_dev.ap);
+		return 0;
+	}
+
 	sas_ha = dev->port->ha;
 
 	sas_read_port_mode_page(scsi_dev);
@@ -592,6 +911,10 @@ int sas_slave_configure(struct scsi_devi
 
 void sas_slave_destroy(struct scsi_device *scsi_dev)
 {
+	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
+
+	if (dev_is_sata(dev))
+		ata_port_disable(dev->sata_dev.ap);
 }
 
 int sas_change_queue_depth(struct scsi_device *scsi_dev, int new_depth)
@@ -763,6 +1086,29 @@ void sas_shutdown_queue(struct sas_ha_st
 	spin_unlock_irqrestore(&core->task_queue_lock, flags);
 }
 
+int sas_slave_alloc(struct scsi_device *scsi_dev)
+{
+	struct domain_device *dev = sdev_to_domain_dev(scsi_dev);
+
+	if (dev_is_sata(dev))
+		return ata_sas_port_init(dev->sata_dev.ap);
+
+	return 0;
+}
+
+void sas_target_destroy(struct scsi_target *starget)
+{
+	struct domain_device *found_dev = sas_find_dev(starget);
+
+	if (!found_dev)
+		return;
+
+	if (dev_is_sata(found_dev))
+		ata_sas_port_destroy(found_dev->sata_dev.ap);
+
+	return;
+}
+
 EXPORT_SYMBOL_GPL(sas_queuecommand);
 EXPORT_SYMBOL_GPL(sas_target_alloc);
 EXPORT_SYMBOL_GPL(sas_slave_configure);
@@ -770,3 +1116,6 @@ EXPORT_SYMBOL_GPL(sas_slave_destroy);
 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
 EXPORT_SYMBOL_GPL(sas_change_queue_type);
 EXPORT_SYMBOL_GPL(sas_bios_param);
+EXPORT_SYMBOL_GPL(sas_slave_alloc);
+EXPORT_SYMBOL_GPL(sas_target_destroy);
+EXPORT_SYMBOL_GPL(sas_ioctl);
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index b109fe5..0aaac5c 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -30,6 +30,7 @@
 #include <linux/timer.h>
 #include <linux/pci.h>
 #include <scsi/sas.h>
+#include <linux/libata.h>
 #include <linux/list.h>
 #include <asm/semaphore.h>
 #include <scsi/scsi_device.h>
@@ -164,6 +165,13 @@ struct sata_device {
 
         u8     port_no;        /* port number, if this is a PM (Port) */
         struct list_head children; /* PM Ports if this is a PM */
+
+	struct ata_port *ap;
+	struct ata_host_set ata_host_set;
+	struct ata_taskfile tf;
+	u32 sstatus;
+	u32 serror;
+	u32 scontrol;
 };
 
 /* ---------- Domain device ---------- */
@@ -626,4 +634,8 @@ void sas_unregister_devices(struct sas_h
 
 void sas_init_dev(struct domain_device *);
 
+extern void sas_target_destroy(struct scsi_target *);
+extern int sas_slave_alloc(struct scsi_device *);
+extern int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg);
+
 #endif /* _SASLIB_H_ */

Re: [PATCH 1/2] Add SATA support to libsas

[Jeff Garzik]

Darrick J. Wong wrote:
> Hook the scsi_host_template functions in libsas to delegate
> functionality to libata when appropriate.
> 
> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>

One piece that seems to be distinctly absent is controlling the SATA 
phy, rather than faking it...

	Jeff

Re: [PATCH 1/2] Add SATA support to libsas

[James Bottomley]

On Thu, 2006-08-10 at 19:19 -0700, Darrick J. Wong wrote:
> +static inline void sas_mark_dev_sata(struct domain_device *dev)
> +{
> +       dev->rphy->identify = dev->port->phy->identify;
> +       dev->rphy->identify.initiator_port_protocols =
> SAS_PROTOCOL_SATA;
> +       dev->rphy->identify.target_port_protocols = SAS_PROTOCOL_SATA;
> +       dev->rphy->identify.device_type = SAS_END_DEVICE;
> +       memcpy(&dev->rphy->identify.sas_address, dev->sas_addr,
> SAS_ADDR_SIZE);
> +}

Actually, this is wrong: you can't memcpy from dev->sas_addr to
identify.sas_addr the former is a big endian u8[8] and the latter is a
u64.  However, the function is unnecessary anyway.  We already have a
sas_fill_in_rphy that does all of this.

James

Index: BUILD-2.6/drivers/scsi/libsas/sas_discover.c
===================================================================
--- BUILD-2.6.orig/drivers/scsi/libsas/sas_discover.c	2006-08-21 21:30:38.000000000 -0500
+++ BUILD-2.6/drivers/scsi/libsas/sas_discover.c	2006-08-21 21:49:22.000000000 -0500
@@ -398,15 +398,6 @@
 	spin_unlock_irqrestore(&port->phy_list_lock, flags);
 }
 
-static inline void sas_mark_dev_sata(struct domain_device *dev)
-{
-	dev->rphy->identify = dev->port->phy->identify;
-	dev->rphy->identify.initiator_port_protocols = SAS_PROTOCOL_SATA;
-	dev->rphy->identify.target_port_protocols = SAS_PROTOCOL_SATA;
-	dev->rphy->identify.device_type = SAS_END_DEVICE;
-	memcpy(&dev->rphy->identify.sas_address, dev->sas_addr, SAS_ADDR_SIZE);
-}
-
 #define ATA_IDENTIFY_DEV         0xEC
 #define ATA_IDENTIFY_PACKET_DEV  0xA1
 #define ATA_SET_FEATURES         0xEF
@@ -490,7 +481,7 @@
 	sas_satl_register_dev(dev);
 	*/
 	
-	sas_mark_dev_sata(dev);
+	sas_fill_in_rphy(dev, dev->rphy);
 
 	res = sas_rphy_add(dev->rphy);
 	if (res)

Re: [PATCH 1/2] Add SATA support to libsas

[James Bottomley]

On Fri, 2006-08-11 at 04:52 -0400, Jeff Garzik wrote:
> One piece that seems to be distinctly absent is controlling the SATA 
> phy, rather than faking it...

Could you elaborate a bit more?  You mean this faking of the SATA
Control Registers?  If so, this is a bit problematic ... SAS HBAs don't
seem to come with SATA Control Registers (and certainly not when the
device is remote over SAT).  We do, however, have reasonable control of
the phys via the transport class.  Probably the best solution is to
expand the ata transport class to abstract this phy control out into
knobs users can twiddle and then put this back down to libata/libsas via
callbacks they can each interpret.

James

Re: [PATCH 1/2] Add SATA support to libsas

[Konrad Rzeszutek]

On Thu, Aug 10, 2006 at 07:19:47PM -0700, Darrick J. Wong wrote:
> Hook the scsi_host_template functions in libsas to delegate
> functionality to libata when appropriate.
> 
> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
> 
> diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
> index b0705ee..76bbb9f 100644
> --- a/drivers/scsi/libsas/sas_discover.c
> +++ b/drivers/scsi/libsas/sas_discover.c

(...)

>  /* ---------- Domain device ---------- */
> @@ -626,4 +634,8 @@ void sas_unregister_devices(struct sas_h
>  
>  void sas_init_dev(struct domain_device *);
>  
> +extern void sas_target_destroy(struct scsi_target *);
> +extern int sas_slave_alloc(struct scsi_device *);
> +extern int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg);
> +

Those should not be 'extern' otherwise the EXPORT_SYMBOL functions 
won't be found when the aic94xx is built as a module.

Re: [PATCH 1/2] Add SATA support to libsas

[Adrian Bunk]

On Fri, Aug 25, 2006 at 03:43:38PM -0400, Konrad Rzeszutek wrote:
> On Thu, Aug 10, 2006 at 07:19:47PM -0700, Darrick J. Wong wrote:
> > Hook the scsi_host_template functions in libsas to delegate
> > functionality to libata when appropriate.
> > 
> > Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
> > 
> > diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
> > index b0705ee..76bbb9f 100644
> > --- a/drivers/scsi/libsas/sas_discover.c
> > +++ b/drivers/scsi/libsas/sas_discover.c
> 
> (...)
> 
> >  /* ---------- Domain device ---------- */
> > @@ -626,4 +634,8 @@ void sas_unregister_devices(struct sas_h
> >  
> >  void sas_init_dev(struct domain_device *);
> >  
> > +extern void sas_target_destroy(struct scsi_target *);
> > +extern int sas_slave_alloc(struct scsi_device *);
> > +extern int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg);
> > +
> 
> Those should not be 'extern' otherwise the EXPORT_SYMBOL functions 
> won't be found when the aic94xx is built as a module.

The "extern"s can be dropped since they don't have any effect, but 
I don't see what problem you are thinking of.

cu
Adrian

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