ARM: dma-mapping: New dma_map_ops->iova_get_free_{total,max} functions
Hiroshi Doyu [Tue, 6 Mar 2012 09:24:16 +0000 (11:24 +0200)]
->iova>_get_free_total() returns the sum of available free areas.
->iova>_get_free_max() returns the largest available free area size.

Change-Id: I817ff46bea799a809e2e6b163b2e86cb737cf077
Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>

arch/arm/include/asm/dma-mapping.h
arch/arm/mm/dma-mapping.c
include/linux/dma-mapping.h

index 2300484..1cbd279 100644 (file)
@@ -170,6 +170,22 @@ static inline void dma_free_attrs(struct device *dev, size_t size,
        ops->free(dev, size, cpu_addr, dma_handle, attrs);
 }
 
+static inline size_t dma_iova_get_free_total(struct device *dev)
+{
+       struct dma_map_ops *ops = get_dma_ops(dev);
+       BUG_ON(!ops);
+
+       return ops->iova_get_free_total(dev);
+}
+
+static inline size_t dma_iova_get_free_max(struct device *dev)
+{
+       struct dma_map_ops *ops = get_dma_ops(dev);
+       BUG_ON(!ops);
+
+       return ops->iova_get_free_max(dev);
+}
+
 /**
  * arm_dma_mmap - map a coherent DMA allocation into user space
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
index e4746b7..db17338 100644 (file)
@@ -1001,6 +1001,57 @@ fs_initcall(dma_debug_do_init);
 
 /* IOMMU */
 
+static size_t arm_iommu_iova_get_free_total(struct device *dev)
+{
+       struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+       unsigned long flags;
+       size_t size = 0;
+       unsigned long start = 0;
+
+       BUG_ON(!dev);
+       BUG_ON(!mapping);
+
+       spin_lock_irqsave(&mapping->lock, flags);
+       while (1) {
+               unsigned long end;
+
+               start = bitmap_find_next_zero_area(mapping->bitmap,
+                                                  mapping->bits, start, 1, 0);
+               if (start > mapping->bits)
+                       break;
+
+               end = find_next_bit(mapping->bitmap, mapping->bits, start);
+               size += end - start;
+               start = end;
+       }
+       spin_unlock_irqrestore(&mapping->lock, flags);
+       return size << (mapping->order + PAGE_SHIFT);
+}
+
+static size_t arm_iommu_iova_get_free_max(struct device *dev)
+{
+       struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+       unsigned long flags;
+       size_t max_free = 0;
+       unsigned long start = 0;
+
+       spin_lock_irqsave(&mapping->lock, flags);
+       while (1) {
+               unsigned long end;
+
+               start = bitmap_find_next_zero_area(mapping->bitmap,
+                                                  mapping->bits, start, 1, 0);
+               if (start > mapping->bits)
+                       break;
+
+               end = find_next_bit(mapping->bitmap, mapping->bits, start);
+               max_free = max_t(size_t, max_free, end - start);
+               start = end;
+       }
+       spin_unlock_irqrestore(&mapping->lock, flags);
+       return max_free << (mapping->order + PAGE_SHIFT);
+}
+
 static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
                                      size_t size)
 {
@@ -1721,6 +1772,9 @@ struct dma_map_ops iommu_ops = {
        .unmap_sg               = arm_iommu_unmap_sg,
        .sync_sg_for_cpu        = arm_iommu_sync_sg_for_cpu,
        .sync_sg_for_device     = arm_iommu_sync_sg_for_device,
+
+       .iova_get_free_total    = arm_iommu_iova_get_free_total,
+       .iova_get_free_max      = arm_iommu_iova_get_free_max,
 };
 
 struct dma_map_ops iommu_coherent_ops = {
index 94af418..0337182 100644 (file)
@@ -53,6 +53,9 @@ struct dma_map_ops {
 #ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
        u64 (*get_required_mask)(struct device *dev);
 #endif
+       size_t (*iova_get_free_total)(struct device *dev);
+       size_t (*iova_get_free_max)(struct device *dev);
+
        int is_phys;
 };