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