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), ddi_dma_lim_sparc(9S) and ddi_dma_lim_x86(9S)). This also is guaranteed to be a power of two.

INTERFACE LEVEL

Solaris DDI specific (Solaris 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_sparc(9S), ddi_dma_lim_x86(9S), ddi_dma_req(9S)

Writing Device Drivers