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, 26 insertions, 4 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b9747fa59e54..2733b0c90b75 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -647,23 +647,45 @@ int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg)
         return rc;
 }
 
+static int ata_ioc32(struct ata_port *ap)
+{
+        if (ap->flags & ATA_FLAG_PIO_DMA)
+                return 1;
+        if (ap->pflags & ATA_PFLAG_PIO32)
+                return 1;
+        return 0;
+}
+
 int ata_sas_scsi_ioctl(struct ata_port *ap, struct scsi_device *scsidev,
                      int cmd, void __user *arg)
 {
         int val = -EINVAL, rc = -EINVAL;
+        unsigned long flags;
 
         switch (cmd) {
         case ATA_IOC_GET_IO32:
-                val = 0;
+                spin_lock_irqsave(ap->lock, flags);
+                val = ata_ioc32(ap);
+                spin_unlock_irqrestore(ap->lock, flags);
                 if (copy_to_user(arg, &val, 1))
                         return -EFAULT;
                 return 0;
 
         case ATA_IOC_SET_IO32:
                 val = (unsigned long) arg;
-                if (val != 0)
-                        return -EINVAL;
-                return 0;
+                rc = 0;
+                spin_lock_irqsave(ap->lock, flags);
+                if (ap->pflags & ATA_PFLAG_PIO32CHANGE) {
+                        if (val)
+                                ap->pflags |= ATA_PFLAG_PIO32;
+                        else
+                                ap->pflags &= ~ATA_PFLAG_PIO32;
+                } else {
+                        if (val != ata_ioc32(ap))
+                                rc = -EINVAL;
+                }
+                spin_unlock_irqrestore(ap->lock, flags);
+                return rc;
 
         case HDIO_GET_IDENTITY:
                 return ata_get_identity(ap, scsidev, arg);