3 files changed, 90 insertions, 48 deletions

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7a996aaa061e..eecc8e60deea 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -298,37 +298,19 @@ static void *
 __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
         const void *caller)
 {
-        struct vm_struct *area;
-        unsigned long addr;
-
         /*
          * DMA allocation can be mapped to user space, so lets
          * set VM_USERMAP flags too.
          */
-        area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
-                                  caller);
-        if (!area)
-                return NULL;
-        addr = (unsigned long)area->addr;
-        area->phys_addr = __pfn_to_phys(page_to_pfn(page));
-
-        if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
-                vunmap((void *)addr);
-                return NULL;
-        }
-        return (void *)addr;
+        return dma_common_contiguous_remap(page, size,
+                        VM_ARM_DMA_CONSISTENT | VM_USERMAP,
+                        prot, caller);
 }
 
 static void __dma_free_remap(void *cpu_addr, size_t size)
 {
-        unsigned int flags = VM_ARM_DMA_CONSISTENT | VM_USERMAP;
-        struct vm_struct *area = find_vm_area(cpu_addr);
-        if (!area || (area->flags & flags) != flags) {
-                WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
-                return;
-        }
-        unmap_kernel_range((unsigned long)cpu_addr, size);
-        vunmap(cpu_addr);
+        dma_common_free_remap(cpu_addr, size,
+                        VM_ARM_DMA_CONSISTENT | VM_USERMAP);
 }
 
 #define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K
@@ -1271,29 +1253,8 @@ static void *
 __iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
                     const void *caller)
 {
-        unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-        struct vm_struct *area;
-        unsigned long p;
-
-        area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
-                                  caller);
-        if (!area)
-                return NULL;
-
-        area->pages = pages;
-        area->nr_pages = nr_pages;
-        p = (unsigned long)area->addr;
-
-        for (i = 0; i < nr_pages; i++) {
-                phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
-                if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
-                        goto err;
-                p += PAGE_SIZE;
-        }
-        return area->addr;
-err:
-        unmap_kernel_range((unsigned long)area->addr, size);
-        vunmap(area->addr);
+        return dma_common_pages_remap(pages, size,
+                        VM_ARM_DMA_CONSISTENT | VM_USERMAP, prot, caller);
         return NULL;
 }
 
@@ -1501,8 +1462,8 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
         }
 
         if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) {
-                unmap_kernel_range((unsigned long)cpu_addr, size);
-                vunmap(cpu_addr);
+                dma_common_free_remap(cpu_addr, size,
+                        VM_ARM_DMA_CONSISTENT | VM_USERMAP);
         }
 
         __iommu_remove_mapping(dev, handle, size);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 6cd08e145bfa..9e8bbdd470ca 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,8 @@
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
 #include <asm-generic/dma-coherent.h>
 
 /*
@@ -267,3 +269,73 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
         return ret;
 }
 EXPORT_SYMBOL(dma_common_mmap);
+
+#ifdef CONFIG_MMU
+/*
+ * remaps an array of PAGE_SIZE pages into another vm_area
+ * Cannot be used in non-sleeping contexts
+ */
+void *dma_common_pages_remap(struct page **pages, size_t size,
+                        unsigned long vm_flags, pgprot_t prot,
+                        const void *caller)
+{
+        struct vm_struct *area;
+
+        area = get_vm_area_caller(size, vm_flags, caller);
+        if (!area)
+                return NULL;
+
+        area->pages = pages;
+
+        if (map_vm_area(area, prot, pages)) {
+                vunmap(area->addr);
+                return NULL;
+        }
+
+        return area->addr;
+}
+
+/*
+ * remaps an allocated contiguous region into another vm_area.
+ * Cannot be used in non-sleeping contexts
+ */
+
+void *dma_common_contiguous_remap(struct page *page, size_t size,
+                        unsigned long vm_flags,
+                        pgprot_t prot, const void *caller)
+{
+        int i;
+        struct page **pages;
+        void *ptr;
+        unsigned long pfn;
+
+        pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
+        if (!pages)
+                return NULL;
+
+        for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
+                pages[i] = pfn_to_page(pfn + i);
+
+        ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+
+        kfree(pages);
+
+        return ptr;
+}
+
+/*
+ * unmaps a range previously mapped by dma_common_*_remap
+ */
+void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
+{
+        struct vm_struct *area = find_vm_area(cpu_addr);
+
+        if (!area || (area->flags & vm_flags) != vm_flags) {
+                WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
+                return;
+        }
+
+        unmap_kernel_range((unsigned long)cpu_addr, size);
+        vunmap(cpu_addr);
+}
+#endif
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index de8bf89940f8..a9fd248f5d48 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -179,6 +179,15 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
                            void *cpu_addr, dma_addr_t dma_addr, size_t size);
 
+void *dma_common_contiguous_remap(struct page *page, size_t size,
+                        unsigned long vm_flags,
+                        pgprot_t prot, const void *caller);
+
+void *dma_common_pages_remap(struct page **pages, size_t size,
+                        unsigned long vm_flags, pgprot_t prot,
+                        const void *caller);
+void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags);
+
 /**
  * dma_mmap_attrs - map a coherent DMA allocation into user space
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices