Merge remote-tracking branch 'arm/for-next'

[karo-tx-linux.git] / arch / arm / mm / dma-mapping.c

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index f5e1a8471714cd421e2ab9dee54ae88f144316d1..644d91f73b00f3c5663b9e273d91d51a50218dd5 100644 (file)
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -159,7 +159,7 @@ EXPORT_SYMBOL(arm_coherent_dma_ops);
 
 static u64 get_coherent_dma_mask(struct device *dev)
 {
-       u64 mask = (u64)arm_dma_limit;
+       u64 mask = (u64)DMA_BIT_MASK(32);
 
        if (dev) {
                mask = dev->coherent_dma_mask;
@@ -173,10 +173,30 @@ static u64 get_coherent_dma_mask(struct device *dev)
                        return 0;
                }
 
-               if ((~mask) & (u64)arm_dma_limit) {
-                       dev_warn(dev, "coherent DMA mask %#llx is smaller "
-                                "than system GFP_DMA mask %#llx\n",
-                                mask, (u64)arm_dma_limit);
+               /*
+                * If the mask allows for more memory than we can address,
+                * and we actually have that much memory, then fail the
+                * allocation.
+                */
+               if (sizeof(mask) != sizeof(dma_addr_t) &&
+                   mask > (dma_addr_t)~0 &&
+                   dma_to_pfn(dev, ~0) > arm_dma_pfn_limit) {
+                       dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n",
+                                mask);
+                       dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n");
+                       return 0;
+               }
+
+               /*
+                * Now check that the mask, when translated to a PFN,
+                * fits within the allowable addresses which we can
+                * allocate.
+                */
+               if (dma_to_pfn(dev, mask) < arm_dma_pfn_limit) {
+                       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,
+                                arm_dma_pfn_limit + 1);
                        return 0;
                }
        }
@@ -1007,8 +1027,27 @@ void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
  */
 int dma_supported(struct device *dev, u64 mask)
 {
-       if (mask < (u64)arm_dma_limit)
+       unsigned long limit;
+
+       /*
+        * If the mask allows for more memory than we can address,
+        * and we actually have that much memory, then we must
+        * indicate that DMA to this device is not supported.
+        */
+       if (sizeof(mask) != sizeof(dma_addr_t) &&
+           mask > (dma_addr_t)~0 &&
+           dma_to_pfn(dev, ~0) > arm_dma_pfn_limit)
                return 0;
+
+       /*
+        * Translate the device's DMA mask to a PFN limit.  This
+        * PFN number includes the page which we can DMA to.
+        */
+       limit = dma_to_pfn(dev, mask);
+
+       if (limit < arm_dma_pfn_limit)
+               return 0;
+
        return 1;
 }
 EXPORT_SYMBOL(dma_supported);
@@ -1232,7 +1271,8 @@ __iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
                                break;
 
                len = (j - i) << PAGE_SHIFT;
-               ret = iommu_map(mapping->domain, iova, phys, len, 0);
+               ret = iommu_map(mapping->domain, iova, phys, len,
+                               IOMMU_READ|IOMMU_WRITE);
                if (ret < 0)
                        goto fail;
                iova += len;
@@ -1431,6 +1471,27 @@ static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
                                         GFP_KERNEL);
 }
 
+static int __dma_direction_to_prot(enum dma_data_direction dir)
+{
+       int prot;
+
+       switch (dir) {
+       case DMA_BIDIRECTIONAL:
+               prot = IOMMU_READ | IOMMU_WRITE;
+               break;
+       case DMA_TO_DEVICE:
+               prot = IOMMU_READ;
+               break;
+       case DMA_FROM_DEVICE:
+               prot = IOMMU_WRITE;
+               break;
+       default:
+               prot = 0;
+       }
+
+       return prot;
+}
+
 /*
  * Map a part of the scatter-gather list into contiguous io address space
  */
@@ -1444,6 +1505,7 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
        int ret = 0;
        unsigned int count;
        struct scatterlist *s;
+       int prot;
 
        size = PAGE_ALIGN(size);
        *handle = DMA_ERROR_CODE;
@@ -1460,7 +1522,9 @@ static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
                        !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
                        __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
 
-               ret = iommu_map(mapping->domain, iova, phys, len, 0);
+               prot = __dma_direction_to_prot(dir);
+
+               ret = iommu_map(mapping->domain, iova, phys, len, prot);
                if (ret < 0)
                        goto fail;
                count += len >> PAGE_SHIFT;
@@ -1665,19 +1729,7 @@ static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *p
        if (dma_addr == DMA_ERROR_CODE)
                return dma_addr;
 
-       switch (dir) {
-       case DMA_BIDIRECTIONAL:
-               prot = IOMMU_READ | IOMMU_WRITE;
-               break;
-       case DMA_TO_DEVICE:
-               prot = IOMMU_READ;
-               break;
-       case DMA_FROM_DEVICE:
-               prot = IOMMU_WRITE;
-               break;
-       default:
-               prot = 0;
-       }
+       prot = __dma_direction_to_prot(dir);
 
        ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
        if (ret < 0)