drm: fix for non-coherent DMA PowerPC

This patch fixes bits of the DRM so to make the radeon DRI work on
non-cache coherent PCI DMA variants of the PowerPC processors.

It moves the few places that needs change to wrappers to that
other architectures with similar issues can easily add their
own changes to those wrappers, at least until we have more useful
generic kernel API.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/char/drm/drm_scatter.c b/drivers/char/drm/drm_scatter.c
index 26d8f675ed5d..b2b0f3d41714 100644
--- a/drivers/char/drm/drm_scatter.c
+++ b/drivers/char/drm/drm_scatter.c
@@ -36,6 +36,15 @@
 
 #define DEBUG_SCATTER 0
 
+static inline void *drm_vmalloc_dma(unsigned long size)
+{
+#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
+        return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE);
+#else
+        return vmalloc_32(size);
+#endif
+}
+
 void drm_sg_cleanup(struct drm_sg_mem * entry)
 {
         struct page *page;
@@ -104,7 +113,7 @@ int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
         }
         memset((void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr));
 
-        entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
+        entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
         if (!entry->virtual) {
                 drm_free(entry->busaddr,
                          entry->pages * sizeof(*entry->busaddr), DRM_MEM_PAGES);