dma_map(D3X)

NAME
     dma_map - load DMA mapping registers for an imminent transfer

SYNOPSIS
     #include "sys/types.h"
     #include "sys/sema.h"
     #include "sys/dmamap.h"

     int dma_map(dmamap_t *dmamap,caddr_t kernel_vaddr, int num_bytes);

DESCRIPTION
     dma_map attempts to map num_bytes of main memory starting at the kernel
     virtual address kernel_vaddr, using the previously allocated DMA map
     dmamap.  dma_map determines the actual physical memory locations for the
     given address and range and loads them into the mapping registers
     corresponding to the map.  These mapping registers remain undisturbed
     until another call to dma_map.

   Return Values
     dma_map returns the actual number of bytes mapped.  This number may be
     less than that requested if the number of map registers required exceeds
     the size of the given DMA map.

     0 is returned if the arguments are invalid, for instance, if a
     kernel_vaddr is not word aligned.

   See Also
     dma_mapaddr(D3X), dma_mapalloc(D3X), dma_mapfree(D3X), vme_adapter(D3X).