ARM/dma-mapping: remove get_coherent_dma_mask

The core DMA code already checks for valid DMA masks earlier on, and
doesn't allow NULL struct device pointers.  Remove the now not required
checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 9414d72f664b7ce806ed1361b7f2645927ef9ac0..72ddc3d0f5ebb29c219ccd46a7351abf89eeeb31 100644 (file)
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -219,7 +219,7 @@ const struct dma_map_ops arm_coherent_dma_ops = {
 };
 EXPORT_SYMBOL(arm_coherent_dma_ops);
 
-static int __dma_supported(struct device *dev, u64 mask, bool warn)
+static int __dma_supported(struct device *dev, u64 mask)
 {
        unsigned long max_dma_pfn = min(max_pfn - 1, arm_dma_pfn_limit);
 
@@ -227,41 +227,11 @@ static int __dma_supported(struct device *dev, u64 mask, bool warn)
         * Translate the device's DMA mask to a PFN limit.  This
         * PFN number includes the page which we can DMA to.
         */
-       if (dma_to_pfn(dev, mask) < max_dma_pfn) {
-               if (warn)
-                       dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n",
-                                mask,
-                                dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1,
-                                max_dma_pfn + 1);
+       if (dma_to_pfn(dev, mask) < max_dma_pfn)
                return 0;
-       }
-
        return 1;
 }
 
-static u64 get_coherent_dma_mask(struct device *dev)
-{
-       u64 mask = (u64)DMA_BIT_MASK(32);
-
-       if (dev) {
-               mask = dev->coherent_dma_mask;
-
-               /*
-                * Sanity check the DMA mask - it must be non-zero, and
-                * must be able to be satisfied by a DMA allocation.
-                */
-               if (mask == 0) {
-                       dev_warn(dev, "coherent DMA mask is unset\n");
-                       return 0;
-               }
-
-               if (!__dma_supported(dev, mask, true))
-                       return 0;
-       }
-
-       return mask;
-}
-
 static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag)
 {
        /*
@@ -688,7 +658,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
                         gfp_t gfp, pgprot_t prot, bool is_coherent,
                         unsigned long attrs, const void *caller)
 {
-       u64 mask = get_coherent_dma_mask(dev);
+       u64 mask = dev->coherent_dma_mask;
        struct page *page = NULL;
        void *addr;
        bool allowblock, cma;
@@ -712,9 +682,6 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
        }
 #endif
 
-       if (!mask)
-               return NULL;
-
        buf = kzalloc(sizeof(*buf),
                      gfp & ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM));
        if (!buf)
@@ -1095,7 +1062,7 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
  */
 int arm_dma_supported(struct device *dev, u64 mask)
 {
-       return __dma_supported(dev, mask, false);
+       return __dma_supported(dev, mask);
 }
 
 static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)