[POWERPC] Fix potential cell IOMMU bug when switching back to default DMA ops

If we get a 64-bit dma mask we switch to the fixed ops and call
cell_dma_dev_setup().  If the driver then switches back to a 32-bit dma
mask for any reason we don't call cell_dma_dev_setup() again, which
has the potential to leave bogus data in dev->archdata.dma_data.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 1f7b254740862418b930c9d06bbf9dd02a3f7e7e..5cdcd3638250c5c662e3c55f7d6efbfefedd141b 100644 (file)
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -841,19 +841,18 @@ static int dma_set_mask_and_switch(struct device *dev, u64 dma_mask)
        if (!dev->dma_mask || !dma_supported(dev, dma_mask))
                return -EIO;
 
-       if (dma_mask == DMA_BIT_MASK(64)) {
-               if (cell_iommu_get_fixed_address(dev) == OF_BAD_ADDR)
-                       dev_dbg(dev, "iommu: 64-bit OK, but bad addr\n");
-               else {
-                       dev_dbg(dev, "iommu: 64-bit OK, using fixed ops\n");
-                       set_dma_ops(dev, &dma_iommu_fixed_ops);
-                       cell_dma_dev_setup(dev);
-               }
+       if (dma_mask == DMA_BIT_MASK(64) &&
+               cell_iommu_get_fixed_address(dev) != OF_BAD_ADDR)
+       {
+               dev_dbg(dev, "iommu: 64-bit OK, using fixed ops\n");
+               set_dma_ops(dev, &dma_iommu_fixed_ops);
        } else {
                dev_dbg(dev, "iommu: not 64-bit, using default ops\n");
                set_dma_ops(dev, get_pci_dma_ops());
        }
 
+       cell_dma_dev_setup(dev);
+
        *dev->dma_mask = dma_mask;
 
        return 0;