libata: make SFF support optional

Now that SFF support is completely separated out from the core layer,
it can be made optional.  Add CONFIG_ATA_SFF and let SFF drivers
depend on it.  If CONFIG_ATA_SFF isn't set, all codes in libata-sff.c
and data structures for SFF support are disabled.  This saves good
number of bytes for small systems.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 037db1883b..db77b90003 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -445,6 +445,7 @@ enum link_pm {
 };
 extern struct class_device_attribute class_device_attr_link_power_management_policy;
 
+#ifdef CONFIG_ATA_SFF
 struct ata_ioports {
         void __iomem            *cmd_addr;
         void __iomem            *data_addr;
@@ -462,6 +463,7 @@ struct ata_ioports {
         void __iomem            *bmdma_addr;
         void __iomem            *scr_addr;
 };
+#endif /* CONFIG_ATA_SFF */
 
 struct ata_host {
         spinlock_t              lock;
@@ -648,7 +650,9 @@ struct ata_port {
         struct ata_prd          *prd;    /* our SG list */
         dma_addr_t              prd_dma; /* and its DMA mapping */
 
+#ifdef CONFIG_ATA_SFF
         struct ata_ioports      ioaddr; /* ATA cmd/ctl/dma register blocks */
+#endif /* CONFIG_ATA_SFF */
 
         u8                      ctl;    /* cache of ATA control register */
         u8                      last_ctl;       /* Cache last written value */
@@ -760,6 +764,7 @@ struct ata_port_operations {
         void (*port_stop)(struct ata_port *ap);
         void (*host_stop)(struct ata_host *host);
 
+#ifdef CONFIG_ATA_SFF
         /*
          * SFF / taskfile oriented ops
          */
@@ -779,6 +784,7 @@ struct ata_port_operations {
         void (*bmdma_start)(struct ata_queued_cmd *qc);
         void (*bmdma_stop)(struct ata_queued_cmd *qc);
         u8   (*bmdma_status)(struct ata_port *ap);
+#endif /* CONFIG_ATA_SFF */
 
         /*
          * Obsolete
@@ -1349,6 +1355,8 @@ static inline struct ata_port *ata_shost_to_port(struct Scsi_Host *host)
 /**************************************************************************
  * SFF - drivers/ata/libata-sff.c
  */
+#ifdef CONFIG_ATA_SFF
+
 extern const struct ata_port_operations ata_sff_port_ops;
 extern const struct ata_port_operations ata_bmdma_port_ops;
 
@@ -1489,5 +1497,6 @@ static inline u8 ata_wait_idle(struct ata_port *ap)
 
         return status;
 }
+#endif /* CONFIG_ATA_SFF */
 
 #endif /* __LINUX_LIBATA_H__ */