v4.19.13 snapshot.
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
new file mode 100644
index 0000000..1db6a6b
--- /dev/null
+++ b/include/linux/dma-mapping.h
@@ -0,0 +1,854 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_DMA_MAPPING_H
+#define _LINUX_DMA_MAPPING_H
+
+#include <linux/sizes.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/dma-debug.h>
+#include <linux/dma-direction.h>
+#include <linux/scatterlist.h>
+#include <linux/bug.h>
+#include <linux/mem_encrypt.h>
+
+/**
+ * List of possible attributes associated with a DMA mapping. The semantics
+ * of each attribute should be defined in Documentation/DMA-attributes.txt.
+ *
+ * DMA_ATTR_WRITE_BARRIER: DMA to a memory region with this attribute
+ * forces all pending DMA writes to complete.
+ */
+#define DMA_ATTR_WRITE_BARRIER		(1UL << 0)
+/*
+ * DMA_ATTR_WEAK_ORDERING: Specifies that reads and writes to the mapping
+ * may be weakly ordered, that is that reads and writes may pass each other.
+ */
+#define DMA_ATTR_WEAK_ORDERING		(1UL << 1)
+/*
+ * DMA_ATTR_WRITE_COMBINE: Specifies that writes to the mapping may be
+ * buffered to improve performance.
+ */
+#define DMA_ATTR_WRITE_COMBINE		(1UL << 2)
+/*
+ * DMA_ATTR_NON_CONSISTENT: Lets the platform to choose to return either
+ * consistent or non-consistent memory as it sees fit.
+ */
+#define DMA_ATTR_NON_CONSISTENT		(1UL << 3)
+/*
+ * DMA_ATTR_NO_KERNEL_MAPPING: Lets the platform to avoid creating a kernel
+ * virtual mapping for the allocated buffer.
+ */
+#define DMA_ATTR_NO_KERNEL_MAPPING	(1UL << 4)
+/*
+ * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of
+ * the CPU cache for the given buffer assuming that it has been already
+ * transferred to 'device' domain.
+ */
+#define DMA_ATTR_SKIP_CPU_SYNC		(1UL << 5)
+/*
+ * DMA_ATTR_FORCE_CONTIGUOUS: Forces contiguous allocation of the buffer
+ * in physical memory.
+ */
+#define DMA_ATTR_FORCE_CONTIGUOUS	(1UL << 6)
+/*
+ * DMA_ATTR_ALLOC_SINGLE_PAGES: This is a hint to the DMA-mapping subsystem
+ * that it's probably not worth the time to try to allocate memory to in a way
+ * that gives better TLB efficiency.
+ */
+#define DMA_ATTR_ALLOC_SINGLE_PAGES	(1UL << 7)
+/*
+ * DMA_ATTR_NO_WARN: This tells the DMA-mapping subsystem to suppress
+ * allocation failure reports (similarly to __GFP_NOWARN).
+ */
+#define DMA_ATTR_NO_WARN	(1UL << 8)
+
+/*
+ * DMA_ATTR_PRIVILEGED: used to indicate that the buffer is fully
+ * accessible at an elevated privilege level (and ideally inaccessible or
+ * at least read-only at lesser-privileged levels).
+ */
+#define DMA_ATTR_PRIVILEGED		(1UL << 9)
+
+/*
+ * A dma_addr_t can hold any valid DMA or bus address for the platform.
+ * It can be given to a device to use as a DMA source or target.  A CPU cannot
+ * reference a dma_addr_t directly because there may be translation between
+ * its physical address space and the bus address space.
+ */
+struct dma_map_ops {
+	void* (*alloc)(struct device *dev, size_t size,
+				dma_addr_t *dma_handle, gfp_t gfp,
+				unsigned long attrs);
+	void (*free)(struct device *dev, size_t size,
+			      void *vaddr, dma_addr_t dma_handle,
+			      unsigned long attrs);
+	int (*mmap)(struct device *, struct vm_area_struct *,
+			  void *, dma_addr_t, size_t,
+			  unsigned long attrs);
+
+	int (*get_sgtable)(struct device *dev, struct sg_table *sgt, void *,
+			   dma_addr_t, size_t, unsigned long attrs);
+
+	dma_addr_t (*map_page)(struct device *dev, struct page *page,
+			       unsigned long offset, size_t size,
+			       enum dma_data_direction dir,
+			       unsigned long attrs);
+	void (*unmap_page)(struct device *dev, dma_addr_t dma_handle,
+			   size_t size, enum dma_data_direction dir,
+			   unsigned long attrs);
+	/*
+	 * map_sg returns 0 on error and a value > 0 on success.
+	 * It should never return a value < 0.
+	 */
+	int (*map_sg)(struct device *dev, struct scatterlist *sg,
+		      int nents, enum dma_data_direction dir,
+		      unsigned long attrs);
+	void (*unmap_sg)(struct device *dev,
+			 struct scatterlist *sg, int nents,
+			 enum dma_data_direction dir,
+			 unsigned long attrs);
+	dma_addr_t (*map_resource)(struct device *dev, phys_addr_t phys_addr,
+			       size_t size, enum dma_data_direction dir,
+			       unsigned long attrs);
+	void (*unmap_resource)(struct device *dev, dma_addr_t dma_handle,
+			   size_t size, enum dma_data_direction dir,
+			   unsigned long attrs);
+	void (*sync_single_for_cpu)(struct device *dev,
+				    dma_addr_t dma_handle, size_t size,
+				    enum dma_data_direction dir);
+	void (*sync_single_for_device)(struct device *dev,
+				       dma_addr_t dma_handle, size_t size,
+				       enum dma_data_direction dir);
+	void (*sync_sg_for_cpu)(struct device *dev,
+				struct scatterlist *sg, int nents,
+				enum dma_data_direction dir);
+	void (*sync_sg_for_device)(struct device *dev,
+				   struct scatterlist *sg, int nents,
+				   enum dma_data_direction dir);
+	void (*cache_sync)(struct device *dev, void *vaddr, size_t size,
+			enum dma_data_direction direction);
+	int (*mapping_error)(struct device *dev, dma_addr_t dma_addr);
+	int (*dma_supported)(struct device *dev, u64 mask);
+#ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
+	u64 (*get_required_mask)(struct device *dev);
+#endif
+};
+
+extern const struct dma_map_ops dma_direct_ops;
+extern const struct dma_map_ops dma_noncoherent_ops;
+extern const struct dma_map_ops dma_virt_ops;
+
+#define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
+
+#define DMA_MASK_NONE	0x0ULL
+
+static inline int valid_dma_direction(int dma_direction)
+{
+	return ((dma_direction == DMA_BIDIRECTIONAL) ||
+		(dma_direction == DMA_TO_DEVICE) ||
+		(dma_direction == DMA_FROM_DEVICE));
+}
+
+static inline int is_device_dma_capable(struct device *dev)
+{
+	return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
+}
+
+#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
+/*
+ * These three functions are only for dma allocator.
+ * Don't use them in device drivers.
+ */
+int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
+				       dma_addr_t *dma_handle, void **ret);
+int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr);
+
+int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
+			    void *cpu_addr, size_t size, int *ret);
+
+void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle);
+int dma_release_from_global_coherent(int order, void *vaddr);
+int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr,
+				  size_t size, int *ret);
+
+#else
+#define dma_alloc_from_dev_coherent(dev, size, handle, ret) (0)
+#define dma_release_from_dev_coherent(dev, order, vaddr) (0)
+#define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0)
+
+static inline void *dma_alloc_from_global_coherent(ssize_t size,
+						   dma_addr_t *dma_handle)
+{
+	return NULL;
+}
+
+static inline int dma_release_from_global_coherent(int order, void *vaddr)
+{
+	return 0;
+}
+
+static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma,
+						void *cpu_addr, size_t size,
+						int *ret)
+{
+	return 0;
+}
+#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
+
+#ifdef CONFIG_HAS_DMA
+#include <asm/dma-mapping.h>
+static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+	if (dev && dev->dma_ops)
+		return dev->dma_ops;
+	return get_arch_dma_ops(dev ? dev->bus : NULL);
+}
+
+static inline void set_dma_ops(struct device *dev,
+			       const struct dma_map_ops *dma_ops)
+{
+	dev->dma_ops = dma_ops;
+}
+#else
+/*
+ * Define the dma api to allow compilation of dma dependent code.
+ * Code that depends on the dma-mapping API needs to set 'depends on HAS_DMA'
+ * in its Kconfig, unless it already depends on <something> || COMPILE_TEST,
+ * where <something> guarantuees the availability of the dma-mapping API.
+ */
+static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
+static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
+					      size_t size,
+					      enum dma_data_direction dir,
+					      unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	dma_addr_t addr;
+
+	BUG_ON(!valid_dma_direction(dir));
+	addr = ops->map_page(dev, virt_to_page(ptr),
+			     offset_in_page(ptr), size,
+			     dir, attrs);
+	debug_dma_map_page(dev, virt_to_page(ptr),
+			   offset_in_page(ptr), size,
+			   dir, addr, true);
+	return addr;
+}
+
+static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
+					  size_t size,
+					  enum dma_data_direction dir,
+					  unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->unmap_page)
+		ops->unmap_page(dev, addr, size, dir, attrs);
+	debug_dma_unmap_page(dev, addr, size, dir, true);
+}
+
+/*
+ * dma_maps_sg_attrs returns 0 on error and > 0 on success.
+ * It should never return a value < 0.
+ */
+static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
+				   int nents, enum dma_data_direction dir,
+				   unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	int ents;
+
+	BUG_ON(!valid_dma_direction(dir));
+	ents = ops->map_sg(dev, sg, nents, dir, attrs);
+	BUG_ON(ents < 0);
+	debug_dma_map_sg(dev, sg, nents, ents, dir);
+
+	return ents;
+}
+
+static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
+				      int nents, enum dma_data_direction dir,
+				      unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	debug_dma_unmap_sg(dev, sg, nents, dir);
+	if (ops->unmap_sg)
+		ops->unmap_sg(dev, sg, nents, dir, attrs);
+}
+
+static inline dma_addr_t dma_map_page_attrs(struct device *dev,
+					    struct page *page,
+					    size_t offset, size_t size,
+					    enum dma_data_direction dir,
+					    unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	dma_addr_t addr;
+
+	BUG_ON(!valid_dma_direction(dir));
+	addr = ops->map_page(dev, page, offset, size, dir, attrs);
+	debug_dma_map_page(dev, page, offset, size, dir, addr, false);
+
+	return addr;
+}
+
+static inline void dma_unmap_page_attrs(struct device *dev,
+					dma_addr_t addr, size_t size,
+					enum dma_data_direction dir,
+					unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->unmap_page)
+		ops->unmap_page(dev, addr, size, dir, attrs);
+	debug_dma_unmap_page(dev, addr, size, dir, false);
+}
+
+static inline dma_addr_t dma_map_resource(struct device *dev,
+					  phys_addr_t phys_addr,
+					  size_t size,
+					  enum dma_data_direction dir,
+					  unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	dma_addr_t addr;
+
+	BUG_ON(!valid_dma_direction(dir));
+
+	/* Don't allow RAM to be mapped */
+	BUG_ON(pfn_valid(PHYS_PFN(phys_addr)));
+
+	addr = phys_addr;
+	if (ops->map_resource)
+		addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
+
+	debug_dma_map_resource(dev, phys_addr, size, dir, addr);
+
+	return addr;
+}
+
+static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
+				      size_t size, enum dma_data_direction dir,
+				      unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->unmap_resource)
+		ops->unmap_resource(dev, addr, size, dir, attrs);
+	debug_dma_unmap_resource(dev, addr, size, dir);
+}
+
+static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
+					   size_t size,
+					   enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_single_for_cpu)
+		ops->sync_single_for_cpu(dev, addr, size, dir);
+	debug_dma_sync_single_for_cpu(dev, addr, size, dir);
+}
+
+static inline void dma_sync_single_for_device(struct device *dev,
+					      dma_addr_t addr, size_t size,
+					      enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_single_for_device)
+		ops->sync_single_for_device(dev, addr, size, dir);
+	debug_dma_sync_single_for_device(dev, addr, size, dir);
+}
+
+static inline void dma_sync_single_range_for_cpu(struct device *dev,
+						 dma_addr_t addr,
+						 unsigned long offset,
+						 size_t size,
+						 enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_single_for_cpu)
+		ops->sync_single_for_cpu(dev, addr + offset, size, dir);
+	debug_dma_sync_single_range_for_cpu(dev, addr, offset, size, dir);
+}
+
+static inline void dma_sync_single_range_for_device(struct device *dev,
+						    dma_addr_t addr,
+						    unsigned long offset,
+						    size_t size,
+						    enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_single_for_device)
+		ops->sync_single_for_device(dev, addr + offset, size, dir);
+	debug_dma_sync_single_range_for_device(dev, addr, offset, size, dir);
+}
+
+static inline void
+dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+		    int nelems, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_sg_for_cpu)
+		ops->sync_sg_for_cpu(dev, sg, nelems, dir);
+	debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir);
+}
+
+static inline void
+dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+		       int nelems, enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->sync_sg_for_device)
+		ops->sync_sg_for_device(dev, sg, nelems, dir);
+	debug_dma_sync_sg_for_device(dev, sg, nelems, dir);
+
+}
+
+#define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
+#define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
+#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, 0)
+#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, 0)
+#define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
+#define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
+
+static inline void
+dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->cache_sync)
+		ops->cache_sync(dev, vaddr, size, dir);
+}
+
+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
+ * @vma: vm_area_struct describing requested user mapping
+ * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
+ * @handle: device-view address returned from dma_alloc_attrs
+ * @size: size of memory originally requested in dma_alloc_attrs
+ * @attrs: attributes of mapping properties requested in dma_alloc_attrs
+ *
+ * Map a coherent DMA buffer previously allocated by dma_alloc_attrs
+ * into user space.  The coherent DMA buffer must not be freed by the
+ * driver until the user space mapping has been released.
+ */
+static inline int
+dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
+	       dma_addr_t dma_addr, size_t size, unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	BUG_ON(!ops);
+	if (ops->mmap)
+		return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
+	return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
+}
+
+#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
+
+int
+dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
+		       void *cpu_addr, dma_addr_t dma_addr, size_t size);
+
+static inline int
+dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, void *cpu_addr,
+		      dma_addr_t dma_addr, size_t size,
+		      unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	BUG_ON(!ops);
+	if (ops->get_sgtable)
+		return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size,
+					attrs);
+	return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size);
+}
+
+#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
+
+#ifndef arch_dma_alloc_attrs
+#define arch_dma_alloc_attrs(dev)	(true)
+#endif
+
+static inline void *dma_alloc_attrs(struct device *dev, size_t size,
+				       dma_addr_t *dma_handle, gfp_t flag,
+				       unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	void *cpu_addr;
+
+	BUG_ON(!ops);
+	WARN_ON_ONCE(dev && !dev->coherent_dma_mask);
+
+	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
+		return cpu_addr;
+
+	/* let the implementation decide on the zone to allocate from: */
+	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
+
+	if (!arch_dma_alloc_attrs(&dev))
+		return NULL;
+	if (!ops->alloc)
+		return NULL;
+
+	cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
+	debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
+	return cpu_addr;
+}
+
+static inline void dma_free_attrs(struct device *dev, size_t size,
+				     void *cpu_addr, dma_addr_t dma_handle,
+				     unsigned long attrs)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!ops);
+
+	if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
+		return;
+	/*
+	 * On non-coherent platforms which implement DMA-coherent buffers via
+	 * non-cacheable remaps, ops->free() may call vunmap(). Thus getting
+	 * this far in IRQ context is a) at risk of a BUG_ON() or trying to
+	 * sleep on some machines, and b) an indication that the driver is
+	 * probably misusing the coherent API anyway.
+	 */
+	WARN_ON(irqs_disabled());
+
+	if (!ops->free || !cpu_addr)
+		return;
+
+	debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
+	ops->free(dev, size, cpu_addr, dma_handle, attrs);
+}
+
+static inline void *dma_alloc_coherent(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t flag)
+{
+	return dma_alloc_attrs(dev, size, dma_handle, flag, 0);
+}
+
+static inline void dma_free_coherent(struct device *dev, size_t size,
+		void *cpu_addr, dma_addr_t dma_handle)
+{
+	return dma_free_attrs(dev, size, cpu_addr, dma_handle, 0);
+}
+
+static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	debug_dma_mapping_error(dev, dma_addr);
+	if (ops->mapping_error)
+		return ops->mapping_error(dev, dma_addr);
+	return 0;
+}
+
+static inline void dma_check_mask(struct device *dev, u64 mask)
+{
+	if (sme_active() && (mask < (((u64)sme_get_me_mask() << 1) - 1)))
+		dev_warn(dev, "SME is active, device will require DMA bounce buffers\n");
+}
+
+static inline int dma_supported(struct device *dev, u64 mask)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	if (!ops)
+		return 0;
+	if (!ops->dma_supported)
+		return 1;
+	return ops->dma_supported(dev, mask);
+}
+
+#ifndef HAVE_ARCH_DMA_SET_MASK
+static inline int dma_set_mask(struct device *dev, u64 mask)
+{
+	if (!dev->dma_mask || !dma_supported(dev, mask))
+		return -EIO;
+
+	dma_check_mask(dev, mask);
+
+	*dev->dma_mask = mask;
+	return 0;
+}
+#endif
+
+static inline u64 dma_get_mask(struct device *dev)
+{
+	if (dev && dev->dma_mask && *dev->dma_mask)
+		return *dev->dma_mask;
+	return DMA_BIT_MASK(32);
+}
+
+#ifdef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
+int dma_set_coherent_mask(struct device *dev, u64 mask);
+#else
+static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
+{
+	if (!dma_supported(dev, mask))
+		return -EIO;
+
+	dma_check_mask(dev, mask);
+
+	dev->coherent_dma_mask = mask;
+	return 0;
+}
+#endif
+
+/*
+ * Set both the DMA mask and the coherent DMA mask to the same thing.
+ * Note that we don't check the return value from dma_set_coherent_mask()
+ * as the DMA API guarantees that the coherent DMA mask can be set to
+ * the same or smaller than the streaming DMA mask.
+ */
+static inline int dma_set_mask_and_coherent(struct device *dev, u64 mask)
+{
+	int rc = dma_set_mask(dev, mask);
+	if (rc == 0)
+		dma_set_coherent_mask(dev, mask);
+	return rc;
+}
+
+/*
+ * Similar to the above, except it deals with the case where the device
+ * does not have dev->dma_mask appropriately setup.
+ */
+static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
+{
+	dev->dma_mask = &dev->coherent_dma_mask;
+	return dma_set_mask_and_coherent(dev, mask);
+}
+
+extern u64 dma_get_required_mask(struct device *dev);
+
+#ifndef arch_setup_dma_ops
+static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
+				      u64 size, const struct iommu_ops *iommu,
+				      bool coherent) { }
+#endif
+
+#ifndef arch_teardown_dma_ops
+static inline void arch_teardown_dma_ops(struct device *dev) { }
+#endif
+
+static inline unsigned int dma_get_max_seg_size(struct device *dev)
+{
+	if (dev->dma_parms && dev->dma_parms->max_segment_size)
+		return dev->dma_parms->max_segment_size;
+	return SZ_64K;
+}
+
+static inline unsigned int dma_set_max_seg_size(struct device *dev,
+						unsigned int size)
+{
+	if (dev->dma_parms) {
+		dev->dma_parms->max_segment_size = size;
+		return 0;
+	}
+	return -EIO;
+}
+
+static inline unsigned long dma_get_seg_boundary(struct device *dev)
+{
+	if (dev->dma_parms && dev->dma_parms->segment_boundary_mask)
+		return dev->dma_parms->segment_boundary_mask;
+	return DMA_BIT_MASK(32);
+}
+
+static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
+{
+	if (dev->dma_parms) {
+		dev->dma_parms->segment_boundary_mask = mask;
+		return 0;
+	}
+	return -EIO;
+}
+
+#ifndef dma_max_pfn
+static inline unsigned long dma_max_pfn(struct device *dev)
+{
+	return (*dev->dma_mask >> PAGE_SHIFT) + dev->dma_pfn_offset;
+}
+#endif
+
+static inline void *dma_zalloc_coherent(struct device *dev, size_t size,
+					dma_addr_t *dma_handle, gfp_t flag)
+{
+	void *ret = dma_alloc_coherent(dev, size, dma_handle,
+				       flag | __GFP_ZERO);
+	return ret;
+}
+
+static inline int dma_get_cache_alignment(void)
+{
+#ifdef ARCH_DMA_MINALIGN
+	return ARCH_DMA_MINALIGN;
+#endif
+	return 1;
+}
+
+/* flags for the coherent memory api */
+#define DMA_MEMORY_EXCLUSIVE		0x01
+
+#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
+int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
+				dma_addr_t device_addr, size_t size, int flags);
+void dma_release_declared_memory(struct device *dev);
+void *dma_mark_declared_memory_occupied(struct device *dev,
+					dma_addr_t device_addr, size_t size);
+#else
+static inline int
+dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
+			    dma_addr_t device_addr, size_t size, int flags)
+{
+	return -ENOSYS;
+}
+
+static inline void
+dma_release_declared_memory(struct device *dev)
+{
+}
+
+static inline void *
+dma_mark_declared_memory_occupied(struct device *dev,
+				  dma_addr_t device_addr, size_t size)
+{
+	return ERR_PTR(-EBUSY);
+}
+#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
+
+#ifdef CONFIG_HAS_DMA
+int dma_configure(struct device *dev);
+void dma_deconfigure(struct device *dev);
+#else
+static inline int dma_configure(struct device *dev)
+{
+	return 0;
+}
+
+static inline void dma_deconfigure(struct device *dev) {}
+#endif
+
+/*
+ * Managed DMA API
+ */
+#ifdef CONFIG_HAS_DMA
+extern void *dmam_alloc_coherent(struct device *dev, size_t size,
+				 dma_addr_t *dma_handle, gfp_t gfp);
+extern void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
+			       dma_addr_t dma_handle);
+#else /* !CONFIG_HAS_DMA */
+static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
+					dma_addr_t *dma_handle, gfp_t gfp)
+{ return NULL; }
+static inline void dmam_free_coherent(struct device *dev, size_t size,
+				      void *vaddr, dma_addr_t dma_handle) { }
+#endif /* !CONFIG_HAS_DMA */
+
+extern void *dmam_alloc_attrs(struct device *dev, size_t size,
+			      dma_addr_t *dma_handle, gfp_t gfp,
+			      unsigned long attrs);
+#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
+extern int dmam_declare_coherent_memory(struct device *dev,
+					phys_addr_t phys_addr,
+					dma_addr_t device_addr, size_t size,
+					int flags);
+extern void dmam_release_declared_memory(struct device *dev);
+#else /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
+static inline int dmam_declare_coherent_memory(struct device *dev,
+				phys_addr_t phys_addr, dma_addr_t device_addr,
+				size_t size, gfp_t gfp)
+{
+	return 0;
+}
+
+static inline void dmam_release_declared_memory(struct device *dev)
+{
+}
+#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
+
+static inline void *dma_alloc_wc(struct device *dev, size_t size,
+				 dma_addr_t *dma_addr, gfp_t gfp)
+{
+	return dma_alloc_attrs(dev, size, dma_addr, gfp,
+			       DMA_ATTR_WRITE_COMBINE);
+}
+#ifndef dma_alloc_writecombine
+#define dma_alloc_writecombine dma_alloc_wc
+#endif
+
+static inline void dma_free_wc(struct device *dev, size_t size,
+			       void *cpu_addr, dma_addr_t dma_addr)
+{
+	return dma_free_attrs(dev, size, cpu_addr, dma_addr,
+			      DMA_ATTR_WRITE_COMBINE);
+}
+#ifndef dma_free_writecombine
+#define dma_free_writecombine dma_free_wc
+#endif
+
+static inline int dma_mmap_wc(struct device *dev,
+			      struct vm_area_struct *vma,
+			      void *cpu_addr, dma_addr_t dma_addr,
+			      size_t size)
+{
+	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size,
+			      DMA_ATTR_WRITE_COMBINE);
+}
+#ifndef dma_mmap_writecombine
+#define dma_mmap_writecombine dma_mmap_wc
+#endif
+
+#ifdef CONFIG_NEED_DMA_MAP_STATE
+#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME
+#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME
+#define dma_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
+#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  (((PTR)->ADDR_NAME) = (VAL))
+#define dma_unmap_len(PTR, LEN_NAME)             ((PTR)->LEN_NAME)
+#define dma_unmap_len_set(PTR, LEN_NAME, VAL)    (((PTR)->LEN_NAME) = (VAL))
+#else
+#define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)
+#define DEFINE_DMA_UNMAP_LEN(LEN_NAME)
+#define dma_unmap_addr(PTR, ADDR_NAME)           (0)
+#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL)  do { } while (0)
+#define dma_unmap_len(PTR, LEN_NAME)             (0)
+#define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
+#endif
+
+#endif