arch/frv/include/asm/scatterlist.h

   1 #ifndef _ASM_SCATTERLIST_H
   2 #define _ASM_SCATTERLIST_H
   3
   4 #include <asm/types.h>
   5
   6 /*
   7  * Drivers must set either ->address or (preferred) page and ->offset
   8  * to indicate where data must be transferred to/from.
   9  *
  10  * Using page is recommended since it handles highmem data as well as
  11  * low mem. ->address is restricted to data which has a virtual mapping, and
  12  * it will go away in the future. Updating to page can be automated very
  13  * easily -- something like
  14  *
  15  * sg->address = some_ptr;
  16  *
  17  * can be rewritten as
  18  *
  19  * sg_set_buf(sg, some_ptr, length);
  20  *
  21  * and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
  22  */
  23 struct scatterlist {
  24 #ifdef CONFIG_DEBUG_SG
  25         unsigned long   sg_magic;
  26 #endif
  27         unsigned long   page_link;
  28         unsigned int    offset;         /* for highmem, page offset */
  29
  30         dma_addr_t      dma_address;
  31         unsigned int    length;
  32 };
  33
  34 /*
  35  * These macros should be used after a pci_map_sg call has been done
  36  * to get bus addresses of each of the SG entries and their lengths.
  37  * You should only work with the number of sg entries pci_map_sg
  38  * returns, or alternatively stop on the first sg_dma_len(sg) which
  39  * is 0.
  40  */
  41 #define sg_dma_address(sg)      ((sg)->dma_address)
  42 #define sg_dma_len(sg)          ((sg)->length)
  43
  44 #define ISA_DMA_THRESHOLD (0xffffffffUL)
  45
  46 #endif /* !_ASM_SCATTERLIST_H */