Merge branch 'for-linus-for-3.6-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

Pull DMA-mapping updates from Marek Szyprowski:
 "Those patches are continuation of my earlier work.

  They contains extensions to DMA-mapping framework to remove limitation
  of the current ARM implementation (like limited total size of DMA
  coherent/write combine buffers), improve performance of buffer sharing
  between devices (attributes to skip cpu cache operations or creation
  of additional kernel mapping for some specific use cases) as well as
  some unification of the common code for dma_mmap_attrs() and
  dma_mmap_coherent() functions.  All extensions have been implemented
  and tested for ARM architecture."

* 'for-linus-for-3.6-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: dma-mapping: add support for DMA_ATTR_SKIP_CPU_SYNC attribute
  common: DMA-mapping: add DMA_ATTR_SKIP_CPU_SYNC attribute
  ARM: dma-mapping: add support for dma_get_sgtable()
  common: dma-mapping: introduce dma_get_sgtable() function
  ARM: dma-mapping: add support for DMA_ATTR_NO_KERNEL_MAPPING attribute
  common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute
  common: dma-mapping: add support for generic dma_mmap_* calls
  ARM: dma-mapping: fix error path for memory allocation failure
  ARM: dma-mapping: add more sanity checks in arm_dma_mmap()
  ARM: dma-mapping: remove custom consistent dma region
  mm: vmalloc: use const void * for caller argument
  scatterlist: add sg_alloc_table_from_pages function

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 6f3676f1559f..3fbedc75e7c5 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <asm-generic/dma-coherent.h>
 
 /*
  * Managed DMA API
@@ -217,4 +218,52 @@ void dmam_release_declared_memory(struct device *dev)
 }
 EXPORT_SYMBOL(dmam_release_declared_memory);
 
+/*
+ * Create scatter-list for the already allocated DMA buffer.
+ */
+int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
+                 void *cpu_addr, dma_addr_t handle, size_t size)
+{
+        struct page *page = virt_to_page(cpu_addr);
+        int ret;
+
+        ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+        if (unlikely(ret))
+                return ret;
+
+        sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+        return 0;
+}
+EXPORT_SYMBOL(dma_common_get_sgtable);
+
 #endif
+
+/*
+ * Create userspace mapping for the DMA-coherent memory.
+ */
+int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+                    void *cpu_addr, dma_addr_t dma_addr, size_t size)
+{
+        int ret = -ENXIO;
+#ifdef CONFIG_MMU
+        unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+        unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+        unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
+        unsigned long off = vma->vm_pgoff;
+
+        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+        if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+                return ret;
+
+        if (off < count && user_count <= (count - off)) {
+                ret = remap_pfn_range(vma, vma->vm_start,
+                                      pfn + off,
+                                      user_count << PAGE_SHIFT,
+                                      vma->vm_page_prot);
+        }
+#endif  /* CONFIG_MMU */
+
+        return ret;
+}
+EXPORT_SYMBOL(dma_common_mmap);