ata: Report 16/32bit PIO as best we can

The legacy old IDE ioctl API for this is a bit primitive so we try
and map stuff sensibly onto it.

- Set PIO over DMA devices to report 32bit
- Add ability to change the PIO32 settings if the controller permits it
- Add that functionality into the sff drivers
- Add that functionality into the VLB legacy driver
- Turn on the 32bit PIO on the ninja32 and add support there

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 8332e97a9de..bb18415d3d6 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -87,6 +87,7 @@ const struct ata_port_operations ata_bmdma32_port_ops = {
         .inherits               = &ata_bmdma_port_ops,
 
         .sff_data_xfer          = ata_sff_data_xfer32,
+        .port_start             = ata_sff_port_start32,
 };
 EXPORT_SYMBOL_GPL(ata_bmdma32_port_ops);
 
@@ -769,6 +770,9 @@ unsigned int ata_sff_data_xfer32(struct ata_device *dev, unsigned char *buf,
         void __iomem *data_addr = ap->ioaddr.data_addr;
         unsigned int words = buflen >> 2;
         int slop = buflen & 3;
+        
+        if (!(ap->pflags & ATA_PFLAG_PIO32))
+                return ata_sff_data_xfer(dev, buf, buflen, rw);
 
         /* Transfer multiple of 4 bytes */
         if (rw == READ)
@@ -2402,6 +2406,29 @@ int ata_sff_port_start(struct ata_port *ap)
 EXPORT_SYMBOL_GPL(ata_sff_port_start);
 
 /**
+ *      ata_sff_port_start32 - Set port up for dma.
+ *      @ap: Port to initialize
+ *
+ *      Called just after data structures for each port are
+ *      initialized.  Allocates space for PRD table if the device
+ *      is DMA capable SFF.
+ *
+ *      May be used as the port_start() entry in ata_port_operations for
+ *      devices that are capable of 32bit PIO.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+int ata_sff_port_start32(struct ata_port *ap)
+{
+        ap->pflags |= ATA_PFLAG_PIO32 | ATA_PFLAG_PIO32CHANGE;
+        if (ap->ioaddr.bmdma_addr)
+                return ata_port_start(ap);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sff_port_start32);
+
+/**
  *      ata_sff_std_ports - initialize ioaddr with standard port offsets.
  *      @ioaddr: IO address structure to be initialized
  *