include/linux/dma-noncoherent.h

   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 <linux/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)
  13 static inline bool dev_is_dma_coherent(struct device *dev)
  14 {
  15         return dev->dma_coherent;
  16 }
  17 #else
  18 static 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  */
  27 static __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
  40 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
  41                 gfp_t gfp, unsigned long attrs);
  42 void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
  43                 dma_addr_t dma_addr, unsigned long attrs);
  44
  45 #ifdef CONFIG_MMU
  46 /*
  47  * Page protection so that devices that can't snoop CPU caches can use the
  48  * memory coherently.  We default to pgprot_noncached which is usually used
  49  * for ioremap as a safe bet, but architectures can override this with less
  50  * strict semantics if possible.
  51  */
  52 #ifndef pgprot_dmacoherent
  53 #define pgprot_dmacoherent(prot)        pgprot_noncached(prot)
  54 #endif
  55
  56 pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs);
  57 #else
  58 static inline pgprot_t dma_pgprot(struct device *dev, pgprot_t prot,
  59                 unsigned long attrs)
  60 {
  61         return prot;    /* no protection bits supported without page tables */
  62 }
  63 #endif /* CONFIG_MMU */
  64
  65 #ifdef CONFIG_DMA_NONCOHERENT_CACHE_SYNC
  66 void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  67                 enum dma_data_direction direction);
  68 #else
  69 static inline void arch_dma_cache_sync(struct device *dev, void *vaddr,
  70                 size_t size, enum dma_data_direction direction)
  71 {
  72 }
  73 #endif /* CONFIG_DMA_NONCOHERENT_CACHE_SYNC */
  74
  75 #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE
  76 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
  77                 enum dma_data_direction dir);
  78 #else
  79 static inline void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
  80                 enum dma_data_direction dir)
  81 {
  82 }
  83 #endif /* ARCH_HAS_SYNC_DMA_FOR_DEVICE */
  84
  85 #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU
  86 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
  87                 enum dma_data_direction dir);
  88 #else
  89 static inline void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
  90                 enum dma_data_direction dir)
  91 {
  92 }
  93 #endif /* ARCH_HAS_SYNC_DMA_FOR_CPU */
  94
  95 #ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL
  96 void arch_sync_dma_for_cpu_all(void);
  97 #else
  98 static inline void arch_sync_dma_for_cpu_all(void)
  99 {
 100 }
 101 #endif /* CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL */
 102
 103 #ifdef CONFIG_ARCH_HAS_DMA_PREP_COHERENT
 104 void arch_dma_prep_coherent(struct page *page, size_t size);
 105 #else
 106 static inline void arch_dma_prep_coherent(struct page *page, size_t size)
 107 {
 108 }
 109 #endif /* CONFIG_ARCH_HAS_DMA_PREP_COHERENT */
 110
 111 void *arch_dma_set_uncached(void *addr, size_t size);
 112 void arch_dma_clear_uncached(void *addr, size_t size);
 113
 114 #endif /* _LINUX_DMA_NONCOHERENT_H */