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>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index c29f1468e164..efa4a18cfb9d 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -798,11 +798,15 @@ static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
         case ATAPI_PROT_NODATA:
                 ap->hsm_task_state = HSM_ST_LAST;
                 break;
+#ifdef CONFIG_ATA_BMDMA
         case ATAPI_PROT_DMA:
                 ap->hsm_task_state = HSM_ST_LAST;
                 /* initiate bmdma */
                 ap->ops->bmdma_start(qc);
                 break;
+#endif /* CONFIG_ATA_BMDMA */
+        default:
+                BUG();
         }
 }
 
@@ -2535,6 +2539,12 @@ EXPORT_SYMBOL_GPL(ata_pci_sff_init_one);
 
 #endif /* CONFIG_PCI */
 
+/*
+ *      BMDMA support
+ */
+
+#ifdef CONFIG_ATA_BMDMA
+
 const struct ata_port_operations ata_bmdma_port_ops = {
         .inherits               = &ata_sff_port_ops,
 
@@ -3287,6 +3297,7 @@ int ata_pci_bmdma_init_one(struct pci_dev *pdev,
 EXPORT_SYMBOL_GPL(ata_pci_bmdma_init_one);
 
 #endif /* CONFIG_PCI */
+#endif /* CONFIG_ATA_BMDMA */
 
 /**
  *      ata_sff_port_init - Initialize SFF/BMDMA ATA port