kernel/dma/direct.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2018 Christoph Hellwig.
   4  *
   5  * DMA operations that map physical memory directly without using an IOMMU.
   6  */
   7 #ifndef _KERNEL_DMA_DIRECT_H
   8 #define _KERNEL_DMA_DIRECT_H
   9
  10 #include <linux/dma-direct.h>
  11
  12 int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
  13                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
  14                 unsigned long attrs);
  15 bool dma_direct_can_mmap(struct device *dev);
  16 int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
  17                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
  18                 unsigned long attrs);
  19 bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
  20 int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
  21                 enum dma_data_direction dir, unsigned long attrs);
  22 size_t dma_direct_max_mapping_size(struct device *dev);
  23
  24 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
  25     defined(CONFIG_SWIOTLB)
  26 void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
  27                 int nents, enum dma_data_direction dir);
  28 #else
  29 static inline void dma_direct_sync_sg_for_device(struct device *dev,
  30                 struct scatterlist *sgl, int nents, enum dma_data_direction dir)
  31 {
  32 }
  33 #endif
  34
  35 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
  36     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
  37     defined(CONFIG_SWIOTLB)
  38 void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
  39                 int nents, enum dma_data_direction dir, unsigned long attrs);
  40 void dma_direct_sync_sg_for_cpu(struct device *dev,
  41                 struct scatterlist *sgl, int nents, enum dma_data_direction dir);
  42 #else
  43 static inline void dma_direct_unmap_sg(struct device *dev,
  44                 struct scatterlist *sgl, int nents, enum dma_data_direction dir,
  45                 unsigned long attrs)
  46 {
  47 }
  48 static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
  49                 struct scatterlist *sgl, int nents, enum dma_data_direction dir)
  50 {
  51 }
  52 #endif
  53
  54 static inline void dma_direct_sync_single_for_device(struct device *dev,
  55                 dma_addr_t addr, size_t size, enum dma_data_direction dir)
  56 {
  57         phys_addr_t paddr = dma_to_phys(dev, addr);
  58
  59         if (unlikely(is_swiotlb_buffer(paddr)))
  60                 swiotlb_sync_single_for_device(dev, paddr, size, dir);
  61
  62         if (!dev_is_dma_coherent(dev))
  63                 arch_sync_dma_for_device(paddr, size, dir);
  64 }
  65
  66 static inline void dma_direct_sync_single_for_cpu(struct device *dev,
  67                 dma_addr_t addr, size_t size, enum dma_data_direction dir)
  68 {
  69         phys_addr_t paddr = dma_to_phys(dev, addr);
  70
  71         if (!dev_is_dma_coherent(dev)) {
  72                 arch_sync_dma_for_cpu(paddr, size, dir);
  73                 arch_sync_dma_for_cpu_all();
  74         }
  75
  76         if (unlikely(is_swiotlb_buffer(paddr)))
  77                 swiotlb_sync_single_for_cpu(dev, paddr, size, dir);
  78
  79         if (dir == DMA_FROM_DEVICE)
  80                 arch_dma_mark_clean(paddr, size);
  81 }
  82
  83 static inline dma_addr_t dma_direct_map_page(struct device *dev,
  84                 struct page *page, unsigned long offset, size_t size,
  85                 enum dma_data_direction dir, unsigned long attrs)
  86 {
  87         phys_addr_t phys = page_to_phys(page) + offset;
  88         dma_addr_t dma_addr = phys_to_dma(dev, phys);
  89
  90         if (unlikely(swiotlb_force == SWIOTLB_FORCE))
  91                 return swiotlb_map(dev, phys, size, dir, attrs);
  92
  93         if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
  94                 if (swiotlb_force != SWIOTLB_NO_FORCE)
  95                         return swiotlb_map(dev, phys, size, dir, attrs);
  96
  97                 dev_WARN_ONCE(dev, 1,
  98                              "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
  99                              &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
 100                 return DMA_MAPPING_ERROR;
 101         }
 102
 103         if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 104                 arch_sync_dma_for_device(phys, size, dir);
 105         return dma_addr;
 106 }
 107
 108 static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
 109                 size_t size, enum dma_data_direction dir, unsigned long attrs)
 110 {
 111         phys_addr_t phys = dma_to_phys(dev, addr);
 112
 113         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 114                 dma_direct_sync_single_for_cpu(dev, addr, size, dir);
 115
 116         if (unlikely(is_swiotlb_buffer(phys)))
 117                 swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs);
 118 }
 119 #endif /* _KERNEL_DMA_DIRECT_H */