'\" te
.\" Copyright (c) 1997, Sun Microsystems, Inc.
.TH ddi_dma_set_sbus64 9F "1 Jan 1997" "SunOS 5.11" "Kernel Functions for Drivers"
.SH NAME
ddi_dma_set_sbus64 \- allow 64-bit transfers on SBus
.SH SYNOPSIS
.LP
.nf
#include <sys/ddi.h> 
#include <sys/sunddi.h> 

\fBint\fR \fBddi_dma_set_sbus64\fR(\fBddi_dma_handle_t\fR \fIhandle\fR, \fBuint_t\fR \fIburstsizes\fR);
.fi

.SH INTERFACE LEVEL
.sp
.LP
Solaris DDI specific (Solaris DDI).
.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIhandle\fR \fR
.ad
.RS 15n
.rt  
The handle filled in by a call to \fBddi_dma_alloc_handle\fR(9F). 
.RE

.sp
.ne 2
.mk
.na
\fB\fIburstsizes\fR \fR
.ad
.RS 15n
.rt  
The possible burst sizes the device's \fBDMA\fR engine can accept in 64-bit mode.
.RE

.SH DESCRIPTION
.sp
.LP
\fBddi_dma_set_sbus64()\fR informs the system that the device wishes to perform 64-bit data transfers on the SBus. The driver must first allocate a  \fBDMA\fR handle using  \fBddi_dma_alloc_handle\fR(9F) with a \fBddi_dma_attr\fR(9S) structure describing the  \fBDMA\fR attributes for a 32-bit transfer mode.
.sp
.LP
\fIburstsizes\fR describes the possible burst sizes the device's  \fBDMA\fR engine can accept in 64-bit mode. It may be  distinct from the burst sizes for 32-bit mode set in the  \fBddi_dma_attr\fR(9S) structure. The system will activate 64-bit SBus transfers if the SBus supports them. Otherwise, the SBus will operate in 32-bit mode.  
.sp
.LP
After  \fBDMA\fR resources have been allocated (see \fBddi_dma_addr_bind_handle\fR(9F) or  \fBddi_dma_buf_bind_handle\fR(9F)), the driver should retrieve the available burst sizes by calling  \fBddi_dma_burstsizes\fR(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.
.SH RETURN VALUES
.sp
.LP
\fBddi_dma_set_sbus64()\fR returns:
.sp
.ne 2
.mk
.na
\fB\fBDDI_SUCCESS\fR \fR
.ad
.RS 16n
.rt  
Successfully set the SBus to 64-bit mode.
.RE

.sp
.ne 2
.mk
.na
\fB\fBDDI_FAILURE\fR \fR
.ad
.RS 16n
.rt  
64-bit mode could not be set.
.RE

.SH CONTEXT
.sp
.LP
\fBddi_dma_set_sbus64()\fR can be called from user, kernel, or interrupt context.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
\fBATTRIBUTE TYPE\fR\fBATTRIBUTE VALUE\fR
_
ArchitectureSBus
.TE

.SH SEE ALSO
.sp
.LP
\fBattributes\fR(5), \fBddi_dma_addr_bind_handle\fR(9F), \fBddi_dma_alloc_handle\fR(9F), \fBddi_dma_buf_bind_handle\fR(9F), \fBddi_dma_burstsizes\fR(9F), \fBddi_dma_attr\fR(9S) 
.SH NOTES
.sp
.LP
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.