ddi_dma_devalign(9F)

NAME

     ddi_dma_devalign - find DMA mapping  alignment  and  minimum
     transfer size

SYNOPSIS

     #include <sys/conf.h>
     #include <sys/ddi.h>
     #include <sys/sunddi.h>

     int ddi_dma_devalign(ddi_dma_handle_t handle, uint_t *align-
     ment, uint_t *minxfr);

INTERFACE LEVEL

     Solaris DDI specific (Solaris DDI).

PARAMETERS

     handle
           The DMA handle filled  in  by  a  successful  call  to
           ddi_dma_setup(9F).

     alignment
           A pointer to an unsigned integer to be filled in  with
           the  minimum required alignment for DMA. The alignment
           is guaranteed to be a power of two.

     minxfr
           A pointer to an unsigned integer to be filled in  with
           the    minimum    effective    transfer    size   (see
           ddi_iomin(9F),        ddi_dma_lim_sparc(9S)        and
           ddi_dma_lim_x86(9S)).  This also is guaranteed to be a
           power of two.

DESCRIPTION

     ddi_dma_devalign() determines after a successful DMA mapping
     (see  ddi_dma_setup(9F)) the minimum required data alignment
     and minimum DMA transfer size.

RETURN VALUES

     ddi_dma_devalign() returns:

     DDI_SUCCESS
           The alignment and minxfr values have been filled.

     DDI_FAILURE
           The handle was illegal.

CONTEXT

     ddi_dma_devalign() can be called from user or interrupt con-
     text.

SEE ALSO

     ddi_dma_setup(9F),   ddi_iomin(9F),   ddi_dma_lim_sparc(9S),
     ddi_dma_lim_x86(9S), ddi_dma_req(9S)

     Writing Device Drivers