ddi_dma_devalign(9F)					   Kernel Functions for Drivers 				      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 *alignment, 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 context.

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

SunOS 5.10							    1 Feb 1994						      ddi_dma_devalign(9F)