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 #include <linux/memremap.h>
  12
  13 int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
  14                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
  15                 unsigned long attrs);
  16 bool dma_direct_can_mmap(struct device *dev);
  17 int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
  18                 void *cpu_addr, dma_addr_t dma_addr, size_t size,
  19                 unsigned long attrs);
  20 bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr);
  21 int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
  22                 enum dma_data_direction dir, unsigned long attrs);
  23 bool dma_direct_all_ram_mapped(struct device *dev);
  24 size_t dma_direct_max_mapping_size(struct device *dev);
  25
  26 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
  27     defined(CONFIG_SWIOTLB)
  28 void dma_direct_sync_sg_for_device(struct device *dev, struct scatterlist *sgl,
  29                 int nents, enum dma_data_direction dir);
  30 #else
  31 static inline void dma_direct_sync_sg_for_device(struct device *dev,
  32                 struct scatterlist *sgl, int nents, enum dma_data_direction dir)
  33 {
  34 }
  35 #endif
  36
  37 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
  38     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
  39     defined(CONFIG_SWIOTLB)
  40 void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
  41                 int nents, enum dma_data_direction dir, unsigned long attrs);
  42 void dma_direct_sync_sg_for_cpu(struct device *dev,
  43                 struct scatterlist *sgl, int nents, enum dma_data_direction dir);
  44 #else
  45 static inline void dma_direct_unmap_sg(struct device *dev,
  46                 struct scatterlist *sgl, int nents, enum dma_data_direction dir,
  47                 unsigned long attrs)
  48 {
  49 }
  50 static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
  51                 struct scatterlist *sgl, int nents, enum dma_data_direction dir)
  52 {
  53 }
  54 #endif
  55
  56 static inline void dma_direct_sync_single_for_device(struct device *dev,
  57                 dma_addr_t addr, size_t size, enum dma_data_direction dir)
  58 {
  59         phys_addr_t paddr = dma_to_phys(dev, addr);
  60
  61         if (unlikely(is_swiotlb_buffer(dev, paddr)))
  62                 swiotlb_sync_single_for_device(dev, paddr, size, dir);
  63
  64         if (!dev_is_dma_coherent(dev))
  65                 arch_sync_dma_for_device(paddr, size, dir);
  66 }
  67
  68 static inline void dma_direct_sync_single_for_cpu(struct device *dev,
  69                 dma_addr_t addr, size_t size, enum dma_data_direction dir)
  70 {
  71         phys_addr_t paddr = dma_to_phys(dev, addr);
  72
  73         if (!dev_is_dma_coherent(dev)) {
  74                 arch_sync_dma_for_cpu(paddr, size, dir);
  75                 arch_sync_dma_for_cpu_all();
  76         }
  77
  78         if (unlikely(is_swiotlb_buffer(dev, paddr)))
  79                 swiotlb_sync_single_for_cpu(dev, paddr, size, dir);
  80
  81         if (dir == DMA_FROM_DEVICE)
  82                 arch_dma_mark_clean(paddr, size);
  83 }
  84
  85 static inline dma_addr_t dma_direct_map_page(struct device *dev,
  86                 struct page *page, unsigned long offset, size_t size,
  87                 enum dma_data_direction dir, unsigned long attrs)
  88 {
  89         phys_addr_t phys = page_to_phys(page) + offset;
  90         dma_addr_t dma_addr = phys_to_dma(dev, phys);
  91
  92         if (is_swiotlb_force_bounce(dev)) {
  93                 if (is_pci_p2pdma_page(page))
  94                         return DMA_MAPPING_ERROR;
  95                 return swiotlb_map(dev, phys, size, dir, attrs);
  96         }
  97
  98         if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||
  99             dma_kmalloc_needs_bounce(dev, size, dir)) {
 100                 if (is_pci_p2pdma_page(page))
 101                         return DMA_MAPPING_ERROR;
 102                 if (is_swiotlb_active(dev))
 103                         return swiotlb_map(dev, phys, size, dir, attrs);
 104
 105                 dev_WARN_ONCE(dev, 1,
 106                              "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
 107                              &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
 108                 return DMA_MAPPING_ERROR;
 109         }
 110
 111         if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 112                 arch_sync_dma_for_device(phys, size, dir);
 113         return dma_addr;
 114 }
 115
 116 static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
 117                 size_t size, enum dma_data_direction dir, unsigned long attrs)
 118 {
 119         phys_addr_t phys = dma_to_phys(dev, addr);
 120
 121         if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 122                 dma_direct_sync_single_for_cpu(dev, addr, size, dir);
 123
 124         if (unlikely(is_swiotlb_buffer(dev, phys)))
 125                 swiotlb_tbl_unmap_single(dev, phys, size, dir,
 126                                          attrs | DMA_ATTR_SKIP_CPU_SYNC);
 127 }
 128 #endif /* _KERNEL_DMA_DIRECT_H */