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authorLaura Abbott <lauraa@codeaurora.org>2014-03-14 19:52:23 (GMT)
committerChanho Park <chanho61.park@samsung.com>2014-04-16 12:36:51 (GMT)
commitdb621579175a7a81097a422e67e689e8242aa43b (patch)
tree15af21465297c7542218a36bcd7dd2230b403ebf
parent5e8d07df5bbdcaeaba8924cb319db926761d1e2c (diff)
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arm64: Implement custom mmap functions for dma mapping
The current dma_ops do not specify an mmap function so maping falls back to the default implementation. There are at least two issues with using the default implementation: 1) The pgprot is always pgprot_noncached (strongly ordered) memory even with coherent operations 2) dma_common_mmap calls virt_to_page on the remapped non-coherent address which leads to invalid memory being mapped. Fix both these issue by implementing a custom mmap function which correctly accounts for remapped addresses and sets vm_pg_prot appropriately. Signed-off-by: Laura Abbott <lauraa@codeaurora.org> [catalin.marinas@arm.com: replaced "arm64_" with "__" prefix for consistency] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/mm/dma-mapping.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 88fbc5e..81eea3d 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -221,9 +221,52 @@ static void __swiotlb_sync_sg_for_device(struct device *dev,
sg->length, dir);
}
+/* vma->vm_page_prot must be set appropriately before calling this function */
+static 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;
+ unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
+ PAGE_SHIFT;
+ unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
+ unsigned long off = vma->vm_pgoff;
+
+ if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
+ if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
+ ret = remap_pfn_range(vma, vma->vm_start,
+ pfn + off,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+ }
+
+ return ret;
+}
+
+static int __swiotlb_mmap_noncoherent(struct device *dev,
+ struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
+{
+ vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
+ return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
+}
+
+static int __swiotlb_mmap_coherent(struct device *dev,
+ struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
+{
+ /* Just use whatever page_prot attributes were specified */
+ return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
+}
+
struct dma_map_ops noncoherent_swiotlb_dma_ops = {
.alloc = __dma_alloc_noncoherent,
.free = __dma_free_noncoherent,
+ .mmap = __swiotlb_mmap_noncoherent,
.map_page = __swiotlb_map_page,
.unmap_page = __swiotlb_unmap_page,
.map_sg = __swiotlb_map_sg_attrs,
@@ -240,6 +283,7 @@ EXPORT_SYMBOL(noncoherent_swiotlb_dma_ops);
struct dma_map_ops coherent_swiotlb_dma_ops = {
.alloc = __dma_alloc_coherent,
.free = __dma_free_coherent,
+ .mmap = __swiotlb_mmap_coherent,
.map_page = swiotlb_map_page,
.unmap_page = swiotlb_unmap_page,
.map_sg = swiotlb_map_sg_attrs,