php man page for ddi_dma_movwin

ddi_dma_movwin(9F)					   Kernel Functions for Drivers 					ddi_dma_movwin(9F)

NAME
       ddi_dma_movwin - shift current DMA window

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

       int ddi_dma_movwin(ddi_dma_handle_t handle, off_t *offp, uint_t *lenp, ddi_dma_cookie_t *cookiep);

INTERFACE LEVEL
       This interface is obsolete. ddi_dma_getwin(9F) should be used instead.

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

       offp	       A  pointer  to  an offset to set the DMA window to. Upon a successful return, it will be filled in with the new offset from
		       the beginning of the object resources are allocated for.

       lenp	       A pointer to a value which must either be the current size of the DMA window (as known from a call to ddi_dma_curwin(9F) or
		       from  a	previous call to ddi_dma_movwin()). Upon a successful return, it will be filled in with the size, in bytes, of the
		       current window.

       cookiep	       A pointer to a DMA cookie (see ddi_dma_cookie(9S)).  Upon a successful return, cookiep is filled in just as if an  implicit
		       ddi_dma_htoc(9F) had been made.

DESCRIPTION
       ddi_dma_movwin() shifts the current DMA window. If a DMA request allows the system to allocate resources for less than the entire object by
       setting the DDI_DMA_PARTIAL flag in the ddi_dma_req(9S) structure, the current DMA window can be shifted by a call to ddi_dma_movwin().

       The caller must first determine the current DMA window size by a call to ddi_dma_curwin(9F). Using the current offset and size of the  win-
       dow  thus  retrieved,  the caller of ddi_dma_movwin() may change the window onto the object by changing the offset by a value which is some
       multiple of the size of the DMA window.

       ddi_dma_movwin() takes care of underlying resource synchronizations required to shift the window. However, if you want to access  the  data
       prior to or after moving the window, further synchronizations using ddi_dma_sync(9F) are required.

       This  function is normally called from an interrupt routine. The first invocation of the DMA engine is done from the driver. All subsequent
       invocations of the DMA engine are done from the interrupt routine. The interrupt routine checks to see if the request has  been	completed.
       If  it  has,  it  returns without invoking another DMA transfer. Otherwise it calls ddi_dma_movwin() to shift the current window and starts
       another DMA transfer.

RETURN VALUES
       ddi_dma_movwin() returns:

       DDI_SUCCESS     The current length and offset are legal and have been set.

       DDI_FAILURE     Otherwise.

CONTEXT
       ddi_dma_movwin() can be called from user or interrupt context.

ATTRIBUTES
       See attributes(5) for a description of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Stability Level 	     |Obsolete			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       attributes(5),  ddi_dma_curwin(9F),  ddi_dma_getwin(9F),   ddi_dma_htoc(9F),   ddi_dma_setup(9F),   ddi_dma_sync(9F),   ddi_dma_cookie(9S),
       ddi_dma_req(9S)

       Writing Device Drivers

WARNINGS
       The caller must guarantee that the resources used by the object are inactive prior to calling this function.

SunOS 5.10							    27 Sep 2002 						ddi_dma_movwin(9F)