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, 4 insertions, 0 deletions

diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 87f54a1db3b0..6b70a624828c 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -42,8 +42,10 @@ static inline int ata_is_builtin_hardreset(ata_reset_fn_t reset)
 {
         if (reset == sata_std_hardreset)
                 return 1;
+#ifdef CONFIG_ATA_SFF
         if (reset == sata_sff_hardreset)
                 return 1;
+#endif
         return 0;
 }
 
@@ -206,9 +208,11 @@ extern int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 extern void ata_eh_finish(struct ata_port *ap);
 
 /* libata-sff.c */
+#ifdef CONFIG_ATA_SFF
 extern void ata_dev_select(struct ata_port *ap, unsigned int device,
                            unsigned int wait, unsigned int can_sleep);
 extern u8 ata_irq_on(struct ata_port *ap);
 extern void ata_pio_task(struct work_struct *work);
+#endif /* CONFIG_ATA_SFF */
 
 #endif /* __LIBATA_H__ */