scsi: libsas: Add LIBSAS_SHT_BASE

There is much duplication in the scsi_host_template structure for the
drivers which use libsas.

Similar to how a standard template is used in libata with __ATA_BASE_SHT,
create a standard template in LIBSAS_SHT_BASE.

Don't set a default for max_sectors at SCSI_DEFAULT_MAX_SECTORS, as
scsi_host_alloc() will default to this value automatically.

Even though some drivers don't set proc_name, it won't make much difference
to set as DRV_NAME.

Also add LIBSAS_SHT_BASE_NO_SLAVE_INIT for the hisi_sas drivers which have
custom .slave_alloc and .slave_configure methods.
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240308114339.1340549-2-john.g.garry@oracle.comReviewed-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/scsi/libsas.h

@@ -726,4 +726,33 @@ void sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event,
 void sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event,
 			   gfp_t gfp_flags);
 
+#define __LIBSAS_SHT_BASE						\
+	.module				= THIS_MODULE,			\
+	.name				= DRV_NAME,			\
+	.proc_name			= DRV_NAME,			\
+	.queuecommand			= sas_queuecommand,		\
+	.dma_need_drain			= ata_scsi_dma_need_drain,	\
+	.target_alloc			= sas_target_alloc,		\
+	.change_queue_depth		= sas_change_queue_depth,	\
+	.bios_param			= sas_bios_param,		\
+	.this_id			= -1,				\
+	.eh_device_reset_handler	= sas_eh_device_reset_handler,	\
+	.eh_target_reset_handler	= sas_eh_target_reset_handler,	\
+	.target_destroy			= sas_target_destroy,		\
+	.ioctl				= sas_ioctl,			\
+
+#ifdef CONFIG_COMPAT
+#define _LIBSAS_SHT_BASE		__LIBSAS_SHT_BASE		\
+	.compat_ioctl			= sas_ioctl,
+#else
+#define _LIBSAS_SHT_BASE		__LIBSAS_SHT_BASE
+#endif
+
+#define LIBSAS_SHT_BASE			_LIBSAS_SHT_BASE		\
+	.slave_configure		= sas_slave_configure,		\
+	.slave_alloc			= sas_slave_alloc,		\
+
+#define LIBSAS_SHT_BASE_NO_SLAVE_INIT	_LIBSAS_SHT_BASE
+
+
 #endif /* _SASLIB_H_ */