common: dma-mapping: add support for generic dma_mmap_* calls
Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a
generic method for implementing mmap user call to dma_map_ops structure.
This patch converts ARM and PowerPC architectures (the only providers of
dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic
dma_map_ops based call and adds a generic cross architecture
definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine
functions.
The generic mmap virt_to_page-based fallback implementation is provided for
architectures which don't provide their own implementation for mmap method.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 6f3676f..db5db02 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
@@ -218,3 +219,33 @@
EXPORT_SYMBOL(dmam_release_declared_memory);
#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);