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, u_int ∗alignment
, u_int ∗minxfr);

ARGUMENTS

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) and ddi_dma_lim(9S)).  This also is guaranteed to be a power of two. 

INTERFACE LEVEL

SPARC architecture specific (SPARC DDI). 

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(9S), ddi_dma_req(9S)

SunOS 5.1 Writing Device Drivers

SunOS 5.2  —  Last change: 24 Oct 1991