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83 lines
2 KiB
C
83 lines
2 KiB
C
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/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Pointer to dma-buf-mapped memory, plus helpers.
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*/
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#ifndef __DMA_BUF_MAP_H__
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#define __DMA_BUF_MAP_H__
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#include <linux/io.h>
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/**
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* struct dma_buf_map - Pointer to vmap'ed dma-buf memory.
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* @vaddr_iomem: The buffer's address if in I/O memory
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* @vaddr: The buffer's address if in system memory
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* @is_iomem: True if the dma-buf memory is located in I/O
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* memory, or false otherwise.
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*/
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struct dma_buf_map {
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union {
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void __iomem *vaddr_iomem;
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void *vaddr;
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};
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bool is_iomem;
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};
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/* API transition helper */
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static inline bool dma_buf_map_is_vaddr(const struct dma_buf_map *map, const void *vaddr)
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{
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return !map->is_iomem && (map->vaddr == vaddr);
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}
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/**
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* dma_buf_map_is_null - Tests for a dma-buf mapping to be NULL
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* @map: The dma-buf mapping structure
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*
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* Depending on the state of struct dma_buf_map.is_iomem, tests if the
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* mapping is NULL.
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*
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* Returns:
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* True if the mapping is NULL, or false otherwise.
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*/
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static inline bool dma_buf_map_is_null(const struct dma_buf_map *map)
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{
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if (map->is_iomem)
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return !map->vaddr_iomem;
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return !map->vaddr;
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}
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/**
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* dma_buf_map_is_set - Tests is the dma-buf mapping has been set
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* @map: The dma-buf mapping structure
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*
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* Depending on the state of struct dma_buf_map.is_iomem, tests if the
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* mapping has been set.
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*
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* Returns:
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* True if the mapping is been set, or false otherwise.
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*/
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static inline bool dma_buf_map_is_set(const struct dma_buf_map *map)
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{
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return !dma_buf_map_is_null(map);
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}
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/**
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* dma_buf_map_clear - Clears a dma-buf mapping structure
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* @map: The dma-buf mapping structure
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*
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* Clears all fields to zero; including struct dma_buf_map.is_iomem. So
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* mapping structures that were set to point to I/O memory are reset for
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* system memory. Pointers are cleared to NULL. This is the default.
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*/
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static inline void dma_buf_map_clear(struct dma_buf_map *map)
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{
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if (map->is_iomem) {
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map->vaddr_iomem = NULL;
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map->is_iomem = false;
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} else {
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map->vaddr = NULL;
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}
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}
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#endif /* __DMA_BUF_MAP_H__ */
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