libata-sff: make BMDMA optional

Make BMDMA optional depending on new config variable CONFIG_ATA_BMDMA.
In Kconfig, drivers are grouped into five groups - non-SFF native, SFF
w/ custom DMA interface, SFF w/ BMDMA, PIO-only SFF, and generic
fallback / legacy ones.  Kconfig and Makefile are reorganized
according to the groups and ordered alphabetically inside each group.

ata_ioports.bmdma_addr and ata_port.bmdma_prd[_dma] are put into
CONFIG_ATA_BMDMA, as are all bmdma related ops, variables and
functions.

This increase the binary size slightly when BMDMA is enabled but on
both native-only and PIO-only configurations the size is slightly
reduced.  Either way, the size difference is insignificant.  This
change is more meaningful to signify the separation between SFF and
BMDMA and as a tool to verify the separation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index fe2be88..4c5eca4 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -513,7 +513,9 @@
 	void __iomem		*command_addr;
 	void __iomem		*altstatus_addr;
 	void __iomem		*ctl_addr;
+#ifdef CONFIG_ATA_BMDMA
 	void __iomem		*bmdma_addr;
+#endif /* CONFIG_ATA_BMDMA */
 	void __iomem		*scr_addr;
 };
 #endif /* CONFIG_ATA_SFF */
@@ -721,8 +723,10 @@
 	u8			ctl;	/* cache of ATA control register */
 	u8			last_ctl;	/* Cache last written value */
 	struct delayed_work	sff_pio_task;
+#ifdef CONFIG_ATA_BMDMA
 	struct ata_bmdma_prd	*bmdma_prd;	/* BMDMA SG list */
 	dma_addr_t		bmdma_prd_dma;	/* and its DMA mapping */
+#endif /* CONFIG_ATA_BMDMA */
 #endif /* CONFIG_ATA_SFF */
 
 	unsigned int		pio_mask;
@@ -856,10 +860,12 @@
 	void (*sff_irq_clear)(struct ata_port *);
 	void (*sff_drain_fifo)(struct ata_queued_cmd *qc);
 
+#ifdef CONFIG_ATA_BMDMA
 	void (*bmdma_setup)(struct ata_queued_cmd *qc);
 	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_BMDMA */
 #endif /* CONFIG_ATA_SFF */
 
 	ssize_t (*em_show)(struct ata_port *ap, char *buf);
@@ -1555,7 +1561,6 @@
 #ifdef CONFIG_ATA_SFF
 
 extern const struct ata_port_operations ata_sff_port_ops;
-extern const struct ata_port_operations ata_bmdma_port_ops;
 extern const struct ata_port_operations ata_bmdma32_port_ops;
 
 /* PIO only, sg_tablesize and dma_boundary limits can be removed */
@@ -1564,11 +1569,6 @@
 	.sg_tablesize		= LIBATA_MAX_PRD,		\
 	.dma_boundary		= ATA_DMA_BOUNDARY
 
-#define ATA_BMDMA_SHT(drv_name)					\
-	ATA_BASE_SHT(drv_name),					\
-	.sg_tablesize		= LIBATA_MAX_PRD,		\
-	.dma_boundary		= ATA_DMA_BOUNDARY
-
 extern void ata_sff_dev_select(struct ata_port *ap, unsigned int device);
 extern u8 ata_sff_check_status(struct ata_port *ap);
 extern void ata_sff_pause(struct ata_port *ap);
@@ -1625,6 +1625,15 @@
 		struct scsi_host_template *sht, void *host_priv, int hflags);
 #endif /* CONFIG_PCI */
 
+#ifdef CONFIG_ATA_BMDMA
+
+extern const struct ata_port_operations ata_bmdma_port_ops;
+
+#define ATA_BMDMA_SHT(drv_name)					\
+	ATA_BASE_SHT(drv_name),					\
+	.sg_tablesize		= LIBATA_MAX_PRD,		\
+	.dma_boundary		= ATA_DMA_BOUNDARY
+
 extern void ata_bmdma_qc_prep(struct ata_queued_cmd *qc);
 extern unsigned int ata_bmdma_qc_issue(struct ata_queued_cmd *qc);
 extern void ata_bmdma_dumb_qc_prep(struct ata_queued_cmd *qc);
@@ -1652,6 +1661,7 @@
 				  struct scsi_host_template *sht,
 				  void *host_priv, int hflags);
 #endif /* CONFIG_PCI */
+#endif /* CONFIG_ATA_BMDMA */
 
 /**
  *	ata_sff_busy_wait - Wait for a port status register