include/linux/dma-mapping.h - SHIFTPHONES/kernel/common - Gitiles

 /* 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-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/core-api/dma-attributes.rst.
  */

 /*
  * 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_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.  It is specific to a
  * given device and there may be a translation between the CPU physical address
  * space and the bus address space.
  *
  * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
  * be used directly in drivers, but checked for using dma_mapping_error()
  * instead.
  */
 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)

 #define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))

 #ifdef CONFIG_DMA_API_DEBUG
 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
 void debug_dma_map_single(struct device *dev, const void *addr,
 		unsigned long len);
 #else
 static inline void debug_dma_mapping_error(struct device *dev,
 		dma_addr_t dma_addr)
 {
 }
 static inline void debug_dma_map_single(struct device *dev, const void *addr,
 		unsigned long len)
 {
 }
 #endif /* CONFIG_DMA_API_DEBUG */

 #ifdef CONFIG_HAS_DMA
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	debug_dma_mapping_error(dev, dma_addr);

 	if (dma_addr == DMA_MAPPING_ERROR)
 		return -ENOMEM;
 	return 0;
 }

 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);
 void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
 		enum dma_data_direction dir, unsigned long attrs);
 int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents,
 		enum dma_data_direction dir, unsigned long attrs);
 void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
 				      int nents, enum dma_data_direction dir,
 				      unsigned long attrs);
 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);
 void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
 		enum dma_data_direction dir, unsigned long attrs);
 void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
 		enum dma_data_direction dir);
 void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
 		size_t size, enum dma_data_direction dir);
 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 		    int nelems, enum dma_data_direction dir);
 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 		       int nelems, enum dma_data_direction dir);
 void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		gfp_t flag, unsigned long attrs);
 void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t dma_handle, unsigned long attrs);
 void *dmam_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		gfp_t gfp, unsigned long attrs);
 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
 		dma_addr_t dma_handle);
 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);
 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);
 bool dma_can_mmap(struct device *dev);
 int dma_supported(struct device *dev, u64 mask);
 int dma_set_mask(struct device *dev, u64 mask);
 int dma_set_coherent_mask(struct device *dev, u64 mask);
 u64 dma_get_required_mask(struct device *dev);
 size_t dma_max_mapping_size(struct device *dev);
 bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
 unsigned long dma_get_merge_boundary(struct device *dev);
 #else /* CONFIG_HAS_DMA */
 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)
 {
 	return DMA_MAPPING_ERROR;
 }
 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)
 {
 }
 static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
 		int nents, enum dma_data_direction dir, unsigned long attrs)
 {
 	return 0;
 }
 static inline void dma_unmap_sg_attrs(struct device *dev,
 		struct scatterlist *sg, int nents, enum dma_data_direction dir,
 		unsigned long attrs)
 {
 }
 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)
 {
 	return DMA_MAPPING_ERROR;
 }
 static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 }
 static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
 		size_t size, enum dma_data_direction dir)
 {
 }
 static inline void dma_sync_single_for_device(struct device *dev,
 		dma_addr_t addr, size_t size, enum dma_data_direction dir)
 {
 }
 static inline void dma_sync_sg_for_cpu(struct device *dev,
 		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
 {
 }
 static inline void dma_sync_sg_for_device(struct device *dev,
 		struct scatterlist *sg, int nelems, enum dma_data_direction dir)
 {
 }
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	return -ENOMEM;
 }
 static inline void *dma_alloc_attrs(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
 {
 	return NULL;
 }
 static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t dma_handle, unsigned long attrs)
 {
 }
 static inline void *dmam_alloc_attrs(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	return NULL;
 }
 static inline void dmam_free_coherent(struct device *dev, size_t size,
 		void *vaddr, dma_addr_t dma_handle)
 {
 }
 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)
 {
 	return -ENXIO;
 }
 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)
 {
 	return -ENXIO;
 }
 static inline bool dma_can_mmap(struct device *dev)
 {
 	return false;
 }
 static inline int dma_supported(struct device *dev, u64 mask)
 {
 	return 0;
 }
 static inline int dma_set_mask(struct device *dev, u64 mask)
 {
 	return -EIO;
 }
 static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
 {
 	return -EIO;
 }
 static inline u64 dma_get_required_mask(struct device *dev)
 {
 	return 0;
 }
 static inline size_t dma_max_mapping_size(struct device *dev)
 {
 	return 0;
 }
 static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
 {
 	return false;
 }
 static inline unsigned long dma_get_merge_boundary(struct device *dev)
 {
 	return 0;
 }
 #endif /* CONFIG_HAS_DMA */

 struct page *dma_alloc_pages(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
 void dma_free_pages(struct device *dev, size_t size, struct page *page,
 		dma_addr_t dma_handle, enum dma_data_direction dir);
 void *dma_alloc_noncoherent(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 		dma_addr_t dma_handle, enum dma_data_direction dir);

 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)
 {
 	/* DMA must never operate on areas that might be remapped. */
 	if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
 			  "rejecting DMA map of vmalloc memory\n"))
 		return DMA_MAPPING_ERROR;
 	debug_dma_map_single(dev, ptr, size);
 	return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
 			size, dir, attrs);
 }

 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)
 {
 	return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
 }

 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)
 {
 	return dma_sync_single_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)
 {
 	return dma_sync_single_for_device(dev, addr + offset, size, dir);
 }

 /**
  * dma_map_sgtable - Map the given buffer for DMA
  * @dev:	The device for which to perform the DMA operation
  * @sgt:	The sg_table object describing the buffer
  * @dir:	DMA direction
  * @attrs:	Optional DMA attributes for the map operation
  *
  * Maps a buffer described by a scatterlist stored in the given sg_table
  * object for the @dir DMA operation by the @dev device. After success the
  * ownership for the buffer is transferred to the DMA domain.  One has to
  * call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the
  * ownership of the buffer back to the CPU domain before touching the
  * buffer by the CPU.
  *
  * Returns 0 on success or -EINVAL on error during mapping the buffer.
  */
 static inline int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
 		enum dma_data_direction dir, unsigned long attrs)
 {
 	int nents;

 	nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
 	if (nents <= 0)
 		return -EINVAL;
 	sgt->nents = nents;
 	return 0;
 }

 /**
  * dma_unmap_sgtable - Unmap the given buffer for DMA
  * @dev:	The device for which to perform the DMA operation
  * @sgt:	The sg_table object describing the buffer
  * @dir:	DMA direction
  * @attrs:	Optional DMA attributes for the unmap operation
  *
  * Unmaps a buffer described by a scatterlist stored in the given sg_table
  * object for the @dir DMA operation by the @dev device. After this function
  * the ownership of the buffer is transferred back to the CPU domain.
  */
 static inline void dma_unmap_sgtable(struct device *dev, struct sg_table *sgt,
 		enum dma_data_direction dir, unsigned long attrs)
 {
 	dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
 }

 /**
  * dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
  * @dev:	The device for which to perform the DMA operation
  * @sgt:	The sg_table object describing the buffer
  * @dir:	DMA direction
  *
  * Performs the needed cache synchronization and moves the ownership of the
  * buffer back to the CPU domain, so it is safe to perform any access to it
  * by the CPU. Before doing any further DMA operations, one has to transfer
  * the ownership of the buffer back to the DMA domain by calling the
  * dma_sync_sgtable_for_device().
  */
 static inline void dma_sync_sgtable_for_cpu(struct device *dev,
 		struct sg_table *sgt, enum dma_data_direction dir)
 {
 	dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
 }

 /**
  * dma_sync_sgtable_for_device - Synchronize the given buffer for DMA
  * @dev:	The device for which to perform the DMA operation
  * @sgt:	The sg_table object describing the buffer
  * @dir:	DMA direction
  *
  * Performs the needed cache synchronization and moves the ownership of the
  * buffer back to the DMA domain, so it is safe to perform the DMA operation.
  * Once finished, one has to call dma_sync_sgtable_for_cpu() or
  * dma_unmap_sgtable().
  */
 static inline void dma_sync_sgtable_for_device(struct device *dev,
 		struct sg_table *sgt, enum dma_data_direction dir)
 {
 	dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, 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)
 #define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
 #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)

 static inline void *dma_alloc_coherent(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp)
 {

 	return dma_alloc_attrs(dev, size, dma_handle, gfp,
 			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 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 u64 dma_get_mask(struct device *dev)
 {
 	if (dev->dma_mask && *dev->dma_mask)
 		return *dev->dma_mask;
 	return DMA_BIT_MASK(32);
 }

 /*
  * 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);
 }

 /**
  * dma_addressing_limited - return if the device is addressing limited
  * @dev:	device to check
  *
  * Return %true if the devices DMA mask is too small to address all memory in
  * the system, else %false.  Lack of addressing bits is the prime reason for
  * bounce buffering, but might not be the only one.
  */
 static inline bool dma_addressing_limited(struct device *dev)
 {
 	return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
 			    dma_get_required_mask(dev);
 }

 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 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 ULONG_MAX;
 }

 /**
  * dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units
  * @dev: device to guery the boundary for
  * @page_shift: ilog() of the IOMMU page size
  *
  * Return the segment boundary in IOMMU page units (which may be different from
  * the CPU page size) for the passed in device.
  *
  * If @dev is NULL a boundary of U32_MAX is assumed, this case is just for
  * non-DMA API callers.
  */
 static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev,
 		unsigned int page_shift)
 {
 	if (!dev)
 		return (U32_MAX >> page_shift) + 1;
 	return (dma_get_seg_boundary(dev) >> page_shift) + 1;
 }

 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;
 }

 static inline int dma_get_cache_alignment(void)
 {
 #ifdef ARCH_DMA_MINALIGN
 	return ARCH_DMA_MINALIGN;
 #endif
 	return 1;
 }

 static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp)
 {
 	return dmam_alloc_attrs(dev, size, dma_handle, gfp,
 			(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
 }

 static inline void *dma_alloc_wc(struct device *dev, size_t size,
 				 dma_addr_t *dma_addr, gfp_t gfp)
 {
 	unsigned long attrs = DMA_ATTR_WRITE_COMBINE;

 	if (gfp & __GFP_NOWARN)
 		attrs |= DMA_ATTR_NO_WARN;

 	return dma_alloc_attrs(dev, size, dma_addr, gfp, attrs);
 }

 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);
 }

 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);
 }

 #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

 /*
  * Legacy interface to set up the dma offset map.  Drivers really should not
  * actually use it, but we have a few legacy cases left.
  */
 int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
 		dma_addr_t dma_start, u64 size);

 extern const struct dma_map_ops dma_virt_ops;

 #endif /* _LINUX_DMA_MAPPING_H */
	/* 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-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/core-api/dma-attributes.rst.
	*/

	/*
	* 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_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. It is specific to a
	* given device and there may be a translation between the CPU physical address
	* space and the bus address space.
	*
	* DMA_MAPPING_ERROR is the magic error code if a mapping failed. It should not
	* be used directly in drivers, but checked for using dma_mapping_error()
	* instead.
	*/
	#define DMA_MAPPING_ERROR (~(dma_addr_t)0)

	#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))

	#ifdef CONFIG_DMA_API_DEBUG
	void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
	void debug_dma_map_single(struct device dev, const void addr,
	unsigned long len);
	#else
	static inline void debug_dma_mapping_error(struct device *dev,
	dma_addr_t dma_addr)
	{
	}
	static inline void debug_dma_map_single(struct device dev, const void addr,
	unsigned long len)
	{
	}
	#endif /* CONFIG_DMA_API_DEBUG */

	#ifdef CONFIG_HAS_DMA
	static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
	{
	debug_dma_mapping_error(dev, dma_addr);

	if (dma_addr == DMA_MAPPING_ERROR)
	return -ENOMEM;
	return 0;
	}

	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);
	void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size,
	enum dma_data_direction dir, unsigned long attrs);
	int dma_map_sg_attrs(struct device dev, struct scatterlist sg, int nents,
	enum dma_data_direction dir, unsigned long attrs);
	void dma_unmap_sg_attrs(struct device dev, struct scatterlist sg,
	int nents, enum dma_data_direction dir,
	unsigned long attrs);
	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);
	void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
	enum dma_data_direction dir, unsigned long attrs);
	void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
	enum dma_data_direction dir);
	void dma_sync_single_for_device(struct device *dev, dma_addr_t addr,
	size_t size, enum dma_data_direction dir);
	void dma_sync_sg_for_cpu(struct device dev, struct scatterlist sg,
	int nelems, enum dma_data_direction dir);
	void dma_sync_sg_for_device(struct device dev, struct scatterlist sg,
	int nelems, enum dma_data_direction dir);
	void dma_alloc_attrs(struct device dev, size_t size, dma_addr_t *dma_handle,
	gfp_t flag, unsigned long attrs);
	void dma_free_attrs(struct device dev, size_t size, void cpu_addr,
	dma_addr_t dma_handle, unsigned long attrs);
	void dmam_alloc_attrs(struct device dev, size_t size, dma_addr_t *dma_handle,
	gfp_t gfp, unsigned long attrs);
	void dmam_free_coherent(struct device dev, size_t size, void vaddr,
	dma_addr_t dma_handle);
	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);
	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);
	bool dma_can_mmap(struct device *dev);
	int dma_supported(struct device *dev, u64 mask);
	int dma_set_mask(struct device *dev, u64 mask);
	int dma_set_coherent_mask(struct device *dev, u64 mask);
	u64 dma_get_required_mask(struct device *dev);
	size_t dma_max_mapping_size(struct device *dev);
	bool dma_need_sync(struct device *dev, dma_addr_t dma_addr);
	unsigned long dma_get_merge_boundary(struct device *dev);
	#else /* CONFIG_HAS_DMA */
	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)
	{
	return DMA_MAPPING_ERROR;
	}
	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)
	{
	}
	static inline int dma_map_sg_attrs(struct device dev, struct scatterlist sg,
	int nents, enum dma_data_direction dir, unsigned long attrs)
	{
	return 0;
	}
	static inline void dma_unmap_sg_attrs(struct device *dev,
	struct scatterlist *sg, int nents, enum dma_data_direction dir,
	unsigned long attrs)
	{
	}
	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)
	{
	return DMA_MAPPING_ERROR;
	}
	static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
	size_t size, enum dma_data_direction dir, unsigned long attrs)
	{
	}
	static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
	size_t size, enum dma_data_direction dir)
	{
	}
	static inline void dma_sync_single_for_device(struct device *dev,
	dma_addr_t addr, size_t size, enum dma_data_direction dir)
	{
	}
	static inline void dma_sync_sg_for_cpu(struct device *dev,
	struct scatterlist *sg, int nelems, enum dma_data_direction dir)
	{
	}
	static inline void dma_sync_sg_for_device(struct device *dev,
	struct scatterlist *sg, int nelems, enum dma_data_direction dir)
	{
	}
	static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
	{
	return -ENOMEM;
	}
	static inline void dma_alloc_attrs(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs)
	{
	return NULL;
	}
	static void dma_free_attrs(struct device dev, size_t size, void cpu_addr,
	dma_addr_t dma_handle, unsigned long attrs)
	{
	}
	static inline void dmam_alloc_attrs(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
	{
	return NULL;
	}
	static inline void dmam_free_coherent(struct device *dev, size_t size,
	void *vaddr, dma_addr_t dma_handle)
	{
	}
	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)
	{
	return -ENXIO;
	}
	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)
	{
	return -ENXIO;
	}
	static inline bool dma_can_mmap(struct device *dev)
	{
	return false;
	}
	static inline int dma_supported(struct device *dev, u64 mask)
	{
	return 0;
	}
	static inline int dma_set_mask(struct device *dev, u64 mask)
	{
	return -EIO;
	}
	static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
	{
	return -EIO;
	}
	static inline u64 dma_get_required_mask(struct device *dev)
	{
	return 0;
	}
	static inline size_t dma_max_mapping_size(struct device *dev)
	{
	return 0;
	}
	static inline bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
	{
	return false;
	}
	static inline unsigned long dma_get_merge_boundary(struct device *dev)
	{
	return 0;
	}
	#endif /* CONFIG_HAS_DMA */

	struct page dma_alloc_pages(struct device dev, size_t size,
	dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
	void dma_free_pages(struct device dev, size_t size, struct page page,
	dma_addr_t dma_handle, enum dma_data_direction dir);
	void dma_alloc_noncoherent(struct device dev, size_t size,
	dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp);
	void dma_free_noncoherent(struct device dev, size_t size, void vaddr,
	dma_addr_t dma_handle, enum dma_data_direction dir);

	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)
	{
	/* DMA must never operate on areas that might be remapped. */
	if (dev_WARN_ONCE(dev, is_vmalloc_addr(ptr),
	"rejecting DMA map of vmalloc memory\n"))
	return DMA_MAPPING_ERROR;
	debug_dma_map_single(dev, ptr, size);
	return dma_map_page_attrs(dev, virt_to_page(ptr), offset_in_page(ptr),
	size, dir, attrs);
	}

	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)
	{
	return dma_unmap_page_attrs(dev, addr, size, dir, attrs);
	}

	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)
	{
	return dma_sync_single_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)
	{
	return dma_sync_single_for_device(dev, addr + offset, size, dir);
	}

	/**
	* dma_map_sgtable - Map the given buffer for DMA
	* @dev: The device for which to perform the DMA operation
	* @sgt: The sg_table object describing the buffer
	* @dir: DMA direction
	* @attrs: Optional DMA attributes for the map operation
	*
	* Maps a buffer described by a scatterlist stored in the given sg_table
	* object for the @dir DMA operation by the @dev device. After success the
	* ownership for the buffer is transferred to the DMA domain. One has to
	* call dma_sync_sgtable_for_cpu() or dma_unmap_sgtable() to move the
	* ownership of the buffer back to the CPU domain before touching the
	* buffer by the CPU.
	*
	* Returns 0 on success or -EINVAL on error during mapping the buffer.
	*/
	static inline int dma_map_sgtable(struct device dev, struct sg_table sgt,
	enum dma_data_direction dir, unsigned long attrs)
	{
	int nents;

	nents = dma_map_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
	if (nents <= 0)
	return -EINVAL;
	sgt->nents = nents;
	return 0;
	}

	/**
	* dma_unmap_sgtable - Unmap the given buffer for DMA
	* @dev: The device for which to perform the DMA operation
	* @sgt: The sg_table object describing the buffer
	* @dir: DMA direction
	* @attrs: Optional DMA attributes for the unmap operation
	*
	* Unmaps a buffer described by a scatterlist stored in the given sg_table
	* object for the @dir DMA operation by the @dev device. After this function
	* the ownership of the buffer is transferred back to the CPU domain.
	*/
	static inline void dma_unmap_sgtable(struct device dev, struct sg_table sgt,
	enum dma_data_direction dir, unsigned long attrs)
	{
	dma_unmap_sg_attrs(dev, sgt->sgl, sgt->orig_nents, dir, attrs);
	}

	/**
	* dma_sync_sgtable_for_cpu - Synchronize the given buffer for CPU access
	* @dev: The device for which to perform the DMA operation
	* @sgt: The sg_table object describing the buffer
	* @dir: DMA direction
	*
	* Performs the needed cache synchronization and moves the ownership of the
	* buffer back to the CPU domain, so it is safe to perform any access to it
	* by the CPU. Before doing any further DMA operations, one has to transfer
	* the ownership of the buffer back to the DMA domain by calling the
	* dma_sync_sgtable_for_device().
	*/
	static inline void dma_sync_sgtable_for_cpu(struct device *dev,
	struct sg_table *sgt, enum dma_data_direction dir)
	{
	dma_sync_sg_for_cpu(dev, sgt->sgl, sgt->orig_nents, dir);
	}

	/**
	* dma_sync_sgtable_for_device - Synchronize the given buffer for DMA
	* @dev: The device for which to perform the DMA operation
	* @sgt: The sg_table object describing the buffer
	* @dir: DMA direction
	*
	* Performs the needed cache synchronization and moves the ownership of the
	* buffer back to the DMA domain, so it is safe to perform the DMA operation.
	* Once finished, one has to call dma_sync_sgtable_for_cpu() or
	* dma_unmap_sgtable().
	*/
	static inline void dma_sync_sgtable_for_device(struct device *dev,
	struct sg_table *sgt, enum dma_data_direction dir)
	{
	dma_sync_sg_for_device(dev, sgt->sgl, sgt->orig_nents, 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)
	#define dma_get_sgtable(d, t, v, h, s) dma_get_sgtable_attrs(d, t, v, h, s, 0)
	#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)

	static inline void dma_alloc_coherent(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t gfp)
	{

	return dma_alloc_attrs(dev, size, dma_handle, gfp,
	(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 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 u64 dma_get_mask(struct device *dev)
	{
	if (dev->dma_mask && *dev->dma_mask)
	return *dev->dma_mask;
	return DMA_BIT_MASK(32);
	}

	/*
	* 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);
	}

	/**
	* dma_addressing_limited - return if the device is addressing limited
	* @dev: device to check
	*
	* Return %true if the devices DMA mask is too small to address all memory in
	* the system, else %false. Lack of addressing bits is the prime reason for
	* bounce buffering, but might not be the only one.
	*/
	static inline bool dma_addressing_limited(struct device *dev)
	{
	return min_not_zero(dma_get_mask(dev), dev->bus_dma_limit) <
	dma_get_required_mask(dev);
	}

	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 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 ULONG_MAX;
	}

	/**
	* dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units
	* @dev: device to guery the boundary for
	* @page_shift: ilog() of the IOMMU page size
	*
	* Return the segment boundary in IOMMU page units (which may be different from
	* the CPU page size) for the passed in device.
	*
	* If @dev is NULL a boundary of U32_MAX is assumed, this case is just for
	* non-DMA API callers.
	*/
	static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev,
	unsigned int page_shift)
	{
	if (!dev)
	return (U32_MAX >> page_shift) + 1;
	return (dma_get_seg_boundary(dev) >> page_shift) + 1;
	}

	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;
	}

	static inline int dma_get_cache_alignment(void)
	{
	#ifdef ARCH_DMA_MINALIGN
	return ARCH_DMA_MINALIGN;
	#endif
	return 1;
	}

	static inline void dmam_alloc_coherent(struct device dev, size_t size,
	dma_addr_t *dma_handle, gfp_t gfp)
	{
	return dmam_alloc_attrs(dev, size, dma_handle, gfp,
	(gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0);
	}

	static inline void dma_alloc_wc(struct device dev, size_t size,
	dma_addr_t *dma_addr, gfp_t gfp)
	{
	unsigned long attrs = DMA_ATTR_WRITE_COMBINE;

	if (gfp & __GFP_NOWARN)
	attrs \|= DMA_ATTR_NO_WARN;

	return dma_alloc_attrs(dev, size, dma_addr, gfp, attrs);
	}

	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);
	}

	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);
	}

	#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

	/*
	* Legacy interface to set up the dma offset map. Drivers really should not
	* actually use it, but we have a few legacy cases left.
	*/
	int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
	dma_addr_t dma_start, u64 size);

	extern const struct dma_map_ops dma_virt_ops;

	#endif /* _LINUX_DMA_MAPPING_H */