drivers/ieee1394/dma.h

   1 /*
   2  * DMA region bookkeeping routines
   3  *
   4  * Copyright (C) 2002 Maas Digital LLC
   5  *
   6  * This code is licensed under the GPL.  See the file COPYING in the root
   7  * directory of the kernel sources for details.
   8  */
   9
  10 #ifndef IEEE1394_DMA_H
  11 #define IEEE1394_DMA_H
  12
  13 #include <asm/types.h>
  14
  15 struct pci_dev;
  16 struct scatterlist;
  17 struct vm_area_struct;
  18
  19 /**
  20  * struct dma_prog_region - small contiguous DMA buffer
  21  * @kvirt:    kernel virtual address
  22  * @dev:      PCI device
  23  * @n_pages:  number of kernel pages
  24  * @bus_addr: base bus address
  25  *
  26  * a small, physically contiguous DMA buffer with random-access, synchronous
  27  * usage characteristics
  28  */
  29 struct dma_prog_region {
  30         unsigned char *kvirt;
  31         struct pci_dev *dev;
  32         unsigned int n_pages;
  33         dma_addr_t bus_addr;
  34 };
  35
  36 /* clear out all fields but do not allocate any memory */
  37 void dma_prog_region_init(struct dma_prog_region *prog);
  38 int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
  39                           struct pci_dev *dev);
  40 void dma_prog_region_free(struct dma_prog_region *prog);
  41
  42 static inline dma_addr_t dma_prog_region_offset_to_bus(
  43                 struct dma_prog_region *prog, unsigned long offset)
  44 {
  45         return prog->bus_addr + offset;
  46 }
  47
  48 /**
  49  * struct dma_region - large non-contiguous DMA buffer
  50  * @virt:        kernel virtual address
  51  * @dev:         PCI device
  52  * @n_pages:     number of kernel pages
  53  * @n_dma_pages: number of IOMMU pages
  54  * @sglist:      IOMMU mapping
  55  * @direction:   PCI_DMA_TODEVICE, etc.
  56  *
  57  * a large, non-physically-contiguous DMA buffer with streaming, asynchronous
  58  * usage characteristics
  59  */
  60 struct dma_region {
  61         unsigned char *kvirt;
  62         struct pci_dev *dev;
  63         unsigned int n_pages;
  64         unsigned int n_dma_pages;
  65         struct scatterlist *sglist;
  66         int direction;
  67 };
  68
  69 void dma_region_init(struct dma_region *dma);
  70 int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
  71                      struct pci_dev *dev, int direction);
  72 void dma_region_free(struct dma_region *dma);
  73 void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
  74                              unsigned long len);
  75 void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
  76                                 unsigned long len);
  77 int  dma_region_mmap(struct dma_region *dma, struct file *file,
  78                      struct vm_area_struct *vma);
  79 dma_addr_t dma_region_offset_to_bus(struct dma_region *dma,
  80                                     unsigned long offset);
  81
  82 /**
  83  * dma_region_i - macro to index into a DMA region (or dma_prog_region)
  84  */
  85 #define dma_region_i(_dma, _type, _index) \
  86         ( ((_type*) ((_dma)->kvirt)) + (_index) )
  87
  88 #endif /* IEEE1394_DMA_H */