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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_DMA_NONCOHERENT_H
3#define _LINUX_DMA_NONCOHERENT_H 1
4
5#include <linux/dma-mapping.h>
6#include <asm/pgtable.h>
7
8#ifdef CONFIG_ARCH_HAS_DMA_COHERENCE_H
9#include <asm/dma-coherence.h>
10#elif defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
11 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
12 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
13static inline bool dev_is_dma_coherent(struct device *dev)
14{
15 return dev->dma_coherent;
16}
17#else
18static inline bool dev_is_dma_coherent(struct device *dev)
19{
20 return true;
21}
22#endif /* CONFIG_ARCH_HAS_DMA_COHERENCE_H */
23
24/*
25 * Check if an allocation needs to be marked uncached to be coherent.
26 */
27static __always_inline bool dma_alloc_need_uncached(struct device *dev,
28 unsigned long attrs)
29{
30 if (dev_is_dma_coherent(dev))
31 return false;
32 if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
33 return false;
34 if (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) &&
35 (attrs & DMA_ATTR_NON_CONSISTENT))
36 return false;
37 return true;
38}
39
40void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
41 gfp_t gfp, unsigned long attrs);
42void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
43 dma_addr_t dma_addr, unsigned long attrs);
44long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,
45 dma_addr_t dma_addr);
46
47#ifdef CONFIG_MMU
48/*
49 * Page protection so that devices that can't snoop CPU caches can use the
50 * memory coherently. We default to pgprot_noncached which is usually used
51 * for ioremap as a safe bet, but architectures can override this with less
52 * strict semantics if possible.
53 */
54#ifndef pgprot_dmacoherent
55#define pgprot_dmacoherent(prot) pgprot_noncached(prot)
56#endif
57
58pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs);
59#else
60static inline pgprot_t dma_pgprot(struct device *dev, pgprot_t prot,
61 unsigned long attrs)
62{
63 return prot; /* no protection bits supported without page tables */
64}
65#endif /* CONFIG_MMU */
66
67#ifdef CONFIG_DMA_NONCOHERENT_CACHE_SYNC
68void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
69 enum dma_data_direction direction);
70#else
71static inline void arch_dma_cache_sync(struct device *dev, void *vaddr,
72 size_t size, enum dma_data_direction direction)
73{
74}
75#endif /* CONFIG_DMA_NONCOHERENT_CACHE_SYNC */
76
77#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE
78void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
79 size_t size, enum dma_data_direction dir);
80#else
81static inline void arch_sync_dma_for_device(struct device *dev,
82 phys_addr_t paddr, size_t size, enum dma_data_direction dir)
83{
84}
85#endif /* ARCH_HAS_SYNC_DMA_FOR_DEVICE */
86
87#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU
88void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
89 size_t size, enum dma_data_direction dir);
90#else
91static inline void arch_sync_dma_for_cpu(struct device *dev,
92 phys_addr_t paddr, size_t size, enum dma_data_direction dir)
93{
94}
95#endif /* ARCH_HAS_SYNC_DMA_FOR_CPU */
96
97#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL
98void arch_sync_dma_for_cpu_all(struct device *dev);
99#else
100static inline void arch_sync_dma_for_cpu_all(struct device *dev)
101{
102}
103#endif /* CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL */
104
105#ifdef CONFIG_ARCH_HAS_DMA_PREP_COHERENT
106void arch_dma_prep_coherent(struct page *page, size_t size);
107#else
108static inline void arch_dma_prep_coherent(struct page *page, size_t size)
109{
110}
111#endif /* CONFIG_ARCH_HAS_DMA_PREP_COHERENT */
112
113void *uncached_kernel_address(void *addr);
114void *cached_kernel_address(void *addr);
115
116#endif /* _LINUX_DMA_NONCOHERENT_H */