ddi_dma_set_sbus64(9F)					   Kernel Functions for Drivers 				    ddi_dma_set_sbus64(9F)

NAME

       ddi_dma_set_sbus64 - allow 64-bit transfers on SBus

SYNOPSIS

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

       int ddi_dma_set_sbus64(ddi_dma_handle_t handle, uint_t burstsizes);

INTERFACE LEVEL

       Solaris DDI specific (Solaris DDI).

PARAMETERS

       handle	      The handle filled in by a call to ddi_dma_alloc_handle(9F).

       burstsizes     The possible burst sizes the device's DMA engine can accept in 64-bit mode.

DESCRIPTION

       ddi_dma_set_sbus64() informs the system that the device wishes to perform 64-bit data transfers on the SBus. The driver must first allocate
       a  DMA handle using  ddi_dma_alloc_handle(9F) with a ddi_dma_attr(9S) structure describing the  DMA attributes for a 32-bit transfer mode.

       burstsizes describes the possible burst sizes the device's  DMA engine can accept in 64-bit mode. It may be  distinct from the burst  sizes
       for  32-bit  mode  set in the  ddi_dma_attr(9S) structure. The system will activate 64-bit SBus transfers if the SBus supports them. Other-
       wise, the SBus will operate in 32-bit mode.

       After  DMA resources have been allocated (see ddi_dma_addr_bind_handle(9F) or  ddi_dma_buf_bind_handle(9F)), the driver should retrieve the
       available  burst sizes by calling  ddi_dma_burstsizes(9F). This function will return the burst sizes  in 64-bit mode if the system was able
       to  activate 64-bit transfers.  Otherwise burst sizes will be  returned in 32-bit mode.

RETURN VALUES

       ddi_dma_set_sbus64() returns:

       DDI_SUCCESS     Successfully set the SBus to 64-bit mode.

       DDI_FAILURE     64-bit mode could not be set.

CONTEXT

       ddi_dma_set_sbus64() can be called from user, kernel, or interrupt context.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |SBus			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       attributes(5),	  ddi_dma_addr_bind_handle(9F),     ddi_dma_alloc_handle(9F),	  ddi_dma_buf_bind_handle(9F),	   ddi_dma_burstsizes(9F),
       ddi_dma_attr(9S)

NOTES

       64-bit  SBus mode is activated on a per SBus slot basis. If there are multiple SBus cards in one slot, they all must operate in 64-bit mode
       or they all must operate in 32-bit mode.

SunOS 5.11							    1 Jan 1997						    ddi_dma_set_sbus64(9F)