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     ˆÆÅ„BuïÄ¿Â ?÷     /* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_DMA_MAPPING_H
#define _LINUX_DMA_MAPPING_H

#include <linux/device.h>
#include <linux/err.h>
#include <linux/dma-direction.h>
#include <linux/scatterlist.h>
#include <linux/bug.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))

struct dma_iova_state {
	dma_addr_t addr;
	u64 __size;
};

/*
 * Use the high bit to mark if we used swiotlb for one or more ranges.
 */
#define DMA_IOVA_USE_SWIOTLB		(1ULL << 63)

static inline size_t dma_iova_size(struct dma_iova_state *state)
{
	/* Casting is needed for 32-bits systems */
	return (size_t)(state->__size & ~DMA_IOVA_USE_SWIOTLB);
}

#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 (unlikely(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);
unsigned 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_directi