libata: separate out ata_host_alloc() and ata_host_register()

Reorganize ata_host_alloc() and its subroutines into the following
three functions.

* ata_host_alloc() : allocates host and its ports.  shost is not
  registered automatically.

* ata_scsi_add_hosts() : allocates and adds shosts associated with an
  ATA host.  Used by ata_host_register().

* ata_host_register() : takes a fully initialized ata_host structure
  and registers it to libata layer and probes it.

Only ata_host_alloc() and ata_host_register() are exported.
ata_device_add() is rewritten using the above functions.  This patch
does not introduce any observable behavior change.  Things worth
mentioning.

* print_id is assigned at registration time and LLDs are allowed to
  overallocate ports and reduce host->n_ports during initialization.
  ata_host_register() will throw away unused ports automatically.

* All SCSI host initialization stuff now resides in
  ata_scsi_add_hosts() in libata-scsi.c, where it should be.

* ipr is now the only user of ata_host_init().  Either kill it by
  converting ipr to use ata_host_alloc() and friends or rename and
  move it to libata-scsi.c
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/libata-scsi.c

@@ -104,7 +104,7 @@ static const u8 def_control_mpage[CONTROL_MPAGE_LEN] = {
  * libata transport template.  libata doesn't do real transport stuff.
  * It just needs the eh_timed_out hook.
  */
-struct scsi_transport_template ata_scsi_transport_template = {
+static struct scsi_transport_template ata_scsi_transport_template = {
 	.eh_strategy_handler	= ata_scsi_error,
 	.eh_timed_out		= ata_scsi_timed_out,
 	.user_scan		= ata_scsi_user_scan,
@@ -2961,6 +2961,48 @@ 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;
+
+		rc = -ENOMEM;
+		shost = scsi_host_alloc(sht, sizeof(struct ata_port *));
+		if (!shost)
+			goto err_alloc;
+
+		*(struct ata_port **)&shost->hostdata[0] = ap;
+		ap->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;
+
+		rc = scsi_add_host(ap->scsi_host, ap->host->dev);
+		if (rc)
+			goto err_add;
+	}
+
+	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)
 {
 	unsigned int i;
@@ -3237,21 +3279,21 @@ struct ata_port *ata_sas_port_alloc(struct ata_host *host,
 				    struct ata_port_info *port_info,
 				    struct Scsi_Host *shost)
 {
-	struct ata_port *ap = kzalloc(sizeof(*ap), GFP_KERNEL);
-	struct ata_probe_ent *ent;
+	struct ata_port *ap;
 
+	ap = ata_port_alloc(host);
 	if (!ap)
 		return NULL;
 
-	ent = ata_probe_ent_alloc(host->dev, port_info);
-	if (!ent) {
-		kfree(ap);
-		return NULL;
-	}
-
-	ata_port_init(ap, host, ent, 0);
+	ap->port_no = 0;
 	ap->lock = shost->host_lock;
-	devm_kfree(host->dev, ent);
+	ap->pio_mask = port_info->pio_mask;
+	ap->mwdma_mask = port_info->mwdma_mask;
+	ap->udma_mask = port_info->udma_mask;
+	ap->flags |= port_info->flags;
+	ap->ops = port_info->port_ops;
+	ap->cbl = ATA_CBL_SATA;
+
 	return ap;
 }
 EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
@@ -3307,8 +3349,10 @@ int ata_sas_port_init(struct ata_port *ap)
 {
 	int rc = ap->ops->port_start(ap);
 
-	if (!rc)
+	if (!rc) {
+		ap->print_id = ata_print_id++;
 		rc = ata_bus_probe(ap);
+	}
 
 	return rc;
 }

drivers/ata/libata.h

@@ -52,6 +52,7 @@ enum {
 	ATA_DNXFER_QUIET	= (1 << 31),
 };
 
+extern unsigned int ata_print_id;
 extern struct workqueue_struct *ata_aux_wq;
 extern int atapi_enabled;
 extern int atapi_dmadir;
@@ -92,10 +93,9 @@ extern int ata_flush_cache(struct ata_device *dev);
 extern void ata_dev_init(struct ata_device *dev);
 extern int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg);
 extern int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg);
-extern void ata_port_init(struct ata_port *ap, struct ata_host *host,
-			  const struct ata_probe_ent *ent, unsigned int port_no);
 extern struct ata_probe_ent *ata_probe_ent_alloc(struct device *dev,
 						 const struct ata_port_info *port);
+extern struct ata_port *ata_port_alloc(struct ata_host *host);
 
 /* libata-acpi.c */
 #ifdef CONFIG_SATA_ACPI
@@ -113,8 +113,8 @@ static inline int ata_acpi_push_id(struct ata_port *ap, unsigned int ix)
 #endif
 
 /* libata-scsi.c */
-extern struct scsi_transport_template ata_scsi_transport_template;
-
+extern int ata_scsi_add_hosts(struct ata_host *host,
+			      struct scsi_host_template *sht);
 extern void ata_scsi_scan_host(struct ata_port *ap);
 extern int ata_scsi_offline_dev(struct ata_device *dev);
 extern void ata_scsi_hotplug(struct work_struct *work);

include/linux/libata.h

@@ -733,7 +733,10 @@ extern int ata_pci_device_resume(struct pci_dev *pdev);
 #endif
 extern int ata_pci_clear_simplex(struct pci_dev *pdev);
 #endif /* CONFIG_PCI */
+extern struct ata_host *ata_host_alloc(struct device *dev, int max_ports);
 extern int ata_host_start(struct ata_host *host);
+extern int ata_host_register(struct ata_host *host,
+			     struct scsi_host_template *sht);
 extern int ata_device_add(const struct ata_probe_ent *ent);
 extern void ata_host_detach(struct ata_host *host);
 extern void ata_host_init(struct ata_host *, struct device *,