ARM: dma-mapping: Introduce __atomic_get_pages() for __iommu_get_pages()

Support atomic allocation in __iommu_get_pages().

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
[moved __atomic_get_pages() under #ifdef CONFIG_ARM_DMA_USE_IOMMU
 to avoid unused fuction warning for no-IOMMU case]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 882eacc6ebc1..54b158df5afa 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1136,10 +1136,22 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si
         return 0;
 }
 
+static struct page **__atomic_get_pages(void *addr)
+{
+        struct dma_pool *pool = &atomic_pool;
+        struct page **pages = pool->pages;
+        int offs = (addr - pool->vaddr) >> PAGE_SHIFT;
+
+        return pages + offs;
+}
+
 static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs)
 {
         struct vm_struct *area;
 
+        if (__in_atomic_pool(cpu_addr, PAGE_SIZE))
+                return __atomic_get_pages(cpu_addr);
+
         if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs))
                 return cpu_addr;