'\" te
.\" Copyright (c) 2006, Sun Microsystems, Inc.
.TH scsi_dmaget 9F "16 Jan 2006" "SunOS 5.11" "Kernel Functions for Drivers"
.SH NAME
scsi_dmaget, scsi_dmafree \- SCSI dma utility routines
.SH SYNOPSIS
.LP
.nf
#include <sys/scsi/scsi.h>

\fBstruct scsi_pkt *\fR\fBscsi_dmaget\fR(\fBstruct scsi_pkt *\fR\fIpkt\fR, 
     \fBopaque_t\fR \fIdmatoken\fR, \fBint\fR\fB(*\fRcallback\fB)(void)\fR);
.fi

.LP
.nf
\fBvoid\fR \fBscsi_dmafree\fR(\fBstruct scsi_pkt *\fR\fIpkt\fR);
.fi

.SH INTERFACE LEVEL
.sp
.LP
These interfaces are obsolete. Use \fBscsi_init_pkt\fR(9F) instead of \fBscsi_dmaget()\fR. Use \fBscsi_destroy_pkt\fR(9F) instead of \fBscsi_dmafree()\fR.
.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIpkt\fR\fR
.ad
.RS 12n
.rt  
A pointer to a \fBscsi_pkt\fR(9S) structure.
.RE

.sp
.ne 2
.mk
.na
\fB\fIdmatoken\fR\fR
.ad
.RS 12n
.rt  
Pointer to an implementation dependent object.
.RE

.sp
.ne 2
.mk
.na
\fB\fIcallback\fR\fR
.ad
.RS 12n
.rt  
Pointer to a callback function, or \fBNULL_FUNC\fR or \fBSLEEP_FUNC.\fR
.RE

.SH DESCRIPTION
.sp
.LP
The \fBscsi_dmaget()\fR function allocates \fBDMA\fR resources for an already allocated \fBSCSI\fR packet. \fIpkt\fR is a pointer to the previously allocated \fBSCSI\fR packet (see \fBscsi_pktalloc\fR(9F)). 
.sp
.LP
The \fIdmatoken\fR parameter is a pointer to an implementation dependent object which defines the length, direction, and address of the data transfer associated with this \fBSCSI \fRpacket (command). The \fIdmatoken\fR must be a pointer to a \fBbuf\fR(9S) structure. If \fIdmatoken\fR is \fINULL\fR, no resources are allocated.
.sp
.LP
The \fIcallback\fR parameter indicates what \fBscsi_dmaget()\fR should do when resources are not available:
.sp
.ne 2
.mk
.na
\fB\fBNULL_FUNC\fR\fR
.ad
.RS 16n
.rt  
Do not wait for resources. Return a \fINULL\fR pointer.
.RE

.sp
.ne 2
.mk
.na
\fB\fBSLEEP_FUNC\fR\fR
.ad
.RS 16n
.rt  
Wait indefinitely for resources.
.RE

.sp
.ne 2
.mk
.na
\fBOther Values\fR
.ad
.RS 16n
.rt  
\fIcallback\fR points to a function which is called when resources may have become available. \fIcallback\fR must return either \fB0\fR (indicating that it attempted to allocate resources but failed to do so again), in which case it is put back on a list to be called again later, or \fB1\fR indicating either success in allocating resources or indicating that it no longer cares for a retry.
.RE

.sp
.LP
The \fBscsi_dmafree()\fR function frees the \fBDMA\fR resources associated with the \fBSCSI\fR packet. The packet itself remains allocated.
.SH RETURN VALUES
.sp
.LP
The \fBscsi_dmaget()\fR function returns a pointer to a \fBscsi_pkt\fR on success. It returns \fBNULL\fR if resources are not available.
.SH CONTEXT
.sp
.LP
If \fIcallback\fR is \fBSLEEP_FUNC\fR, then this routine may only be called from user or kernel context. Otherwise, it may be called from user, kernel, or interrupt context. The \fIcallback\fR function may not block or call routines that block.
.sp
.LP
The \fBscsi_dmafree()\fR function can be called from user, interrupt, or kernel context.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for a description 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
_
Stability LevelObsolete
.TE

.SH SEE ALSO
.sp
.LP
\fBattributes\fR(5), \fBscsi_pktalloc\fR(9F), \fBscsi_pktfree\fR(9F), \fBscsi_resalloc\fR(9F), \fBscsi_resfree\fR(9F), \fBbuf\fR(9S), \fBscsi_pkt\fR(9S)
.sp
.LP
\fIWriting Device Drivers for Oracle Solaris 11.2\fR
.SH NOTES
.sp
.LP
The \fBscsi_dmaget()\fR and \fBscsi_dmafree()\fR functions are obsolete and will be discontinued in a future release. These functions have been replaced by, respectively, \fBscsi_init_pkt\fR(9F) and \fBscsi_destroy_pkt\fR(9F).