LXR linux/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
  15struct file;
  16struct pci_dev;
  17struct scatterlist;
  18struct 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 */
  30struct 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 */
  38void dma_prog_region_init(struct dma_prog_region *prog);
  39int dma_prog_region_alloc(struct dma_prog_region *prog, unsigned long n_bytes,
  40                          struct pci_dev *dev);
  41void dma_prog_region_free(struct dma_prog_region *prog);
  42
  43static 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 */
  61struct 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
  70void dma_region_init(struct dma_region *dma);
  71int dma_region_alloc(struct dma_region *dma, unsigned long n_bytes,
  72                     struct pci_dev *dev, int direction);
  73void dma_region_free(struct dma_region *dma);
  74void dma_region_sync_for_cpu(struct dma_region *dma, unsigned long offset,
  75                             unsigned long len);
  76void dma_region_sync_for_device(struct dma_region *dma, unsigned long offset,
  77                                unsigned long len);
  78int  dma_region_mmap(struct dma_region *dma, struct file *file,
  79                     struct vm_area_struct *vma);
  80dma_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 */
  90