solaris Man Page: ddi_dma

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ddi_dma_coff(9F) manual page Table of Contents

Name

ddi_dma_coff - convert a DMA cookie to an offset within a DMA handle

Synopsis

#include <sys/conf.h>

#include <sys/ddi.h>

#include <sys/sunddi.h>

int ddi_dma_coff(ddi_dma_handle_t handle, ddi_dma_cookie_t *cookiep, off_t *offp);

Arguments

handle: The handle filled in by a call to ddi_dma_setup(9F) .
cookiep: A pointer to a DMA cookie (see ddi_dma_cookie(9S) ) that contains the appropriate address, length and bus type to be used in programming the DMA engine.
offp: A pointer to an offset to be filled in.

Description

ddi_dma_coff() converts the values in DMA cookie pointed to by cookiep to an offset (in bytes) from the beginning of the object that the DMA handle has mapped.

ddi_dma_coff() allows a driver to update a DMA cookie with values it reads from its device’s DMA engine after a transfer completes and convert that value into an offset into the object that is mapped for DMA.

Return Values

ddi_dma_coff() returns:

DDI_SUCCESS

Successfully filled in offp.

DDI_FAILURE

Failed to successfully fill in offp.

Context

ddi_dma_coff() can be called from user or interrupt context.