arm64: Implement coherent DMA API based on swiotlb
This patch adds support for DMA API cache maintenance on SoCs without
hardware device cache coherency.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index afa91a2..88fbc5e 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -78,7 +78,166 @@
}
}
-static struct dma_map_ops coherent_swiotlb_dma_ops = {
+static void *__dma_alloc_noncoherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flags,
+ struct dma_attrs *attrs)
+{
+ struct page *page, **map;
+ void *ptr, *coherent_ptr;
+ int order, i;
+
+ size = PAGE_ALIGN(size);
+ order = get_order(size);
+
+ ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
+ if (!ptr)
+ goto no_mem;
+ map = kmalloc(sizeof(struct page *) << order, flags & ~GFP_DMA);
+ if (!map)
+ goto no_map;
+
+ /* remove any dirty cache lines on the kernel alias */
+ __dma_flush_range(ptr, ptr + size);
+
+ /* create a coherent mapping */
+ page = virt_to_page(ptr);
+ for (i = 0; i < (size >> PAGE_SHIFT); i++)
+ map[i] = page + i;
+ coherent_ptr = vmap(map, size >> PAGE_SHIFT, VM_MAP,
+ pgprot_dmacoherent(pgprot_default));
+ kfree(map);
+ if (!coherent_ptr)
+ goto no_map;
+
+ return coherent_ptr;
+
+no_map:
+ __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
+no_mem:
+ *dma_handle = ~0;
+ return NULL;
+}
+
+static void __dma_free_noncoherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle,
+ struct dma_attrs *attrs)
+{
+ void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
+
+ vunmap(vaddr);
+ __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
+}
+
+static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ dma_addr_t dev_addr;
+
+ dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
+ __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+
+ return dev_addr;
+}
+
+
+static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+ swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
+}
+
+static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
+ int nelems, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct scatterlist *sg;
+ int i, ret;
+
+ ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
+ for_each_sg(sgl, sg, ret, i)
+ __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
+ sg->length, dir);
+
+ return ret;
+}
+
+static void __swiotlb_unmap_sg_attrs(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(sgl, sg, nelems, i)
+ __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
+ sg->length, dir);
+ swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
+}
+
+static void __swiotlb_sync_single_for_cpu(struct device *dev,
+ dma_addr_t dev_addr, size_t size,
+ enum dma_data_direction dir)
+{
+ __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+ swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
+}
+
+static void __swiotlb_sync_single_for_device(struct device *dev,
+ dma_addr_t dev_addr, size_t size,
+ enum dma_data_direction dir)
+{
+ swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
+ __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
+}
+
+static void __swiotlb_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ for_each_sg(sgl, sg, nelems, i)
+ __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
+ sg->length, dir);
+ swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
+}
+
+static void __swiotlb_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
+ for_each_sg(sgl, sg, nelems, i)
+ __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
+ sg->length, dir);
+}
+
+struct dma_map_ops noncoherent_swiotlb_dma_ops = {
+ .alloc = __dma_alloc_noncoherent,
+ .free = __dma_free_noncoherent,
+ .map_page = __swiotlb_map_page,
+ .unmap_page = __swiotlb_unmap_page,
+ .map_sg = __swiotlb_map_sg_attrs,
+ .unmap_sg = __swiotlb_unmap_sg_attrs,
+ .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
+ .sync_single_for_device = __swiotlb_sync_single_for_device,
+ .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
+ .sync_sg_for_device = __swiotlb_sync_sg_for_device,
+ .dma_supported = swiotlb_dma_supported,
+ .mapping_error = swiotlb_dma_mapping_error,
+};
+EXPORT_SYMBOL(noncoherent_swiotlb_dma_ops);
+
+struct dma_map_ops coherent_swiotlb_dma_ops = {
.alloc = __dma_alloc_coherent,
.free = __dma_free_coherent,
.map_page = swiotlb_map_page,
@@ -92,6 +251,7 @@
.dma_supported = swiotlb_dma_supported,
.mapping_error = swiotlb_dma_mapping_error,
};
+EXPORT_SYMBOL(coherent_swiotlb_dma_ops);
extern int swiotlb_late_init_with_default_size(size_t default_size);