[PATCH] libata: implement ata_unpack_xfermask()

Implement ata_unpack_xfermask().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index f3c115b5568107eb52f1ee2ca75d41b899a1ae2f..1514cb5e35f70ae67ed9957524cdeae10e59ba86 100644 (file)
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -252,6 +252,29 @@ static unsigned int ata_pack_xfermask(unsigned int pio_mask,
                ((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
 }
 
+/**
+ *     ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
+ *     @xfer_mask: xfer_mask to unpack
+ *     @pio_mask: resulting pio_mask
+ *     @mwdma_mask: resulting mwdma_mask
+ *     @udma_mask: resulting udma_mask
+ *
+ *     Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
+ *     Any NULL distination masks will be ignored.
+ */
+static void ata_unpack_xfermask(unsigned int xfer_mask,
+                               unsigned int *pio_mask,
+                               unsigned int *mwdma_mask,
+                               unsigned int *udma_mask)
+{
+       if (pio_mask)
+               *pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
+       if (mwdma_mask)
+               *mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
+       if (udma_mask)
+               *udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
+}
+
 static const struct ata_xfer_ent {
        unsigned int shift, bits;
        u8 base;