1 files changed, 37 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 4f0959fbfbee..8593f53c4f6c 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -96,6 +96,18 @@ static int dma_direct_dma_supported(struct device *dev, u64 mask)
 #endif
 }
 
+static u64 dma_direct_get_required_mask(struct device *dev)
+{
+        u64 end, mask;
+
+        end = memblock_end_of_DRAM() + get_dma_offset(dev);
+
+        mask = 1ULL << (fls64(end) - 1);
+        mask += mask - 1;
+
+        return mask;
+}
+
 static inline dma_addr_t dma_direct_map_page(struct device *dev,
                                              struct page *page,
                                              unsigned long offset,
@@ -137,13 +149,14 @@ static inline void dma_direct_sync_single(struct device *dev,
 #endif
 
 struct dma_map_ops dma_direct_ops = {
-        .alloc_coherent = dma_direct_alloc_coherent,
-        .free_coherent  = dma_direct_free_coherent,
-        .map_sg         = dma_direct_map_sg,
-        .unmap_sg       = dma_direct_unmap_sg,
-        .dma_supported  = dma_direct_dma_supported,
-        .map_page       = dma_direct_map_page,
-        .unmap_page     = dma_direct_unmap_page,
+        .alloc_coherent                 = dma_direct_alloc_coherent,
+        .free_coherent                  = dma_direct_free_coherent,
+        .map_sg                         = dma_direct_map_sg,
+        .unmap_sg                       = dma_direct_unmap_sg,
+        .dma_supported                  = dma_direct_dma_supported,
+        .map_page                       = dma_direct_map_page,
+        .unmap_page                     = dma_direct_unmap_page,
+        .get_required_mask              = dma_direct_get_required_mask,
 #ifdef CONFIG_NOT_COHERENT_CACHE
         .sync_single_for_cpu            = dma_direct_sync_single,
         .sync_single_for_device         = dma_direct_sync_single,
@@ -170,6 +183,23 @@ int dma_set_mask(struct device *dev, u64 dma_mask)
 }
 EXPORT_SYMBOL(dma_set_mask);
 
+u64 dma_get_required_mask(struct device *dev)
+{
+        struct dma_map_ops *dma_ops = get_dma_ops(dev);
+
+        if (ppc_md.dma_get_required_mask)
+                return ppc_md.dma_get_required_mask(dev);
+
+        if (unlikely(dma_ops == NULL))
+                return 0;
+
+        if (dma_ops->get_required_mask)
+                return dma_ops->get_required_mask(dev);
+
+        return DMA_BIT_MASK(8 * sizeof(dma_addr_t));
+}
+EXPORT_SYMBOL_GPL(dma_get_required_mask);
+
 static int __init dma_init(void)
 {
        dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);