drm/nouveau/ttm: set the DMA mask for platform devices

So far the DMA mask was not set for platform devices, which limited them
to a 32-bit physical space. Allow dma_set_mask() to be called for
non-PCI devices, and also take the IOMMU bit into account since it could
restrict the physically addressable space.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c
index bd287c2..3f713c1 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
@@ -29,6 +29,9 @@
 #include "nouveau_gem.h"
 
 #include "drm_legacy.h"
+
+#include <core/tegra.h>
+
 static int
 nouveau_vram_manager_init(struct ttm_mem_type_manager *man, unsigned long psize)
 {
@@ -353,16 +356,26 @@ nouveau_ttm_init(struct nouveau_drm *drm)
                if (drm->agp.bridge ||
                     !dma_supported(dev->dev, DMA_BIT_MASK(bits)))
                        bits = 32;
+       } else if (device->func->tegra) {
+               struct nvkm_device_tegra *tegra = device->func->tegra(device);
 
-               ret = dma_set_mask(dev->dev, DMA_BIT_MASK(bits));
-               if (ret)
-                       return ret;
+               /*
+                * If the platform can use a IOMMU, then the addressable DMA
+                * space is constrained by the IOMMU bit
+                */
+               if (tegra->func->iommu_bit)
+                       bits = min(bits, tegra->func->iommu_bit);
 
-               ret = dma_set_coherent_mask(dev->dev, DMA_BIT_MASK(bits));
-               if (ret)
-                       dma_set_coherent_mask(dev->dev, DMA_BIT_MASK(32));
        }
 
+       ret = dma_set_mask(dev->dev, DMA_BIT_MASK(bits));
+       if (ret)
+               return ret;
+
+       ret = dma_set_coherent_mask(dev->dev, DMA_BIT_MASK(bits));
+       if (ret)
+               dma_set_coherent_mask(dev->dev, DMA_BIT_MASK(32));
+
        ret = nouveau_ttm_global_init(drm);
        if (ret)
                return ret;