'\" te
.\"  Copyright (c) 2000 Sun Microsystems, Inc., All Rights Reserved.
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
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.TH ddi_dma_cookie 9S "30 Sep 1996" "SunOS 5.11" "Data Structures for Drivers"
.SH NAME
ddi_dma_cookie \- DMA address cookie
.SH SYNOPSIS
.LP
.nf
#include <sys/sunddi.h>
.fi

.SH INTERFACE LEVEL
.sp
.LP
Solaris DDI specific (Solaris DDI).
.SH DESCRIPTION
.sp
.LP
The \fBddi_dma_cookie_t\fR structure contains \fBDMA\fR address information
required to program a \fBDMA\fR engine. The structure is filled in by a call to
\fBddi_dma_getwin\fR(9F), \fBddi_dma_addr_bind_handle\fR(9F), or
\fBddi_dma_buf_bind_handle\fR(9F), to get device-specific \fBDMA\fR transfer
information for a \fBDMA\fR request or a \fBDMA\fR window.
.SH STRUCTURE MEMBERS
.sp
.in +2
.nf
typedef struct {
    union {
            uint64_t        _dmac_ll;    /* 64 bit DMA add. */
            uint32_t        _dmac_la[2]; /* 2 x 32 bit add. */
    } _dmu;
    size_t          dmac_size;   /* DMA cookie size */
    uint_t          dmac_type;   /* bus spec. type bits */
} ddi_dma_cookie_t;
.fi
.in -2

.sp
.LP
You can access the DMA address through the \fB#define\fRs: \fBdmac_address\fR
for 32-bit addresses and \fBdmac_laddress\fR for 64-bit addresses. These macros
are defined as follows:
.sp
.in +2
.nf
#define dmac_laddress   _dmu._dmac_ll
#ifdef _LONG_LONG_HTOL
#define dmac_notused    _dmu._dmac_la[0]
#define dmac_address    _dmu._dmac_la[1]
#else
#define dmac_address    _dmu._dmac_la[0]
#define dmac_notused    _dmu._dmac_la[1]
#endif
.fi
.in -2

.sp
.LP
\fBdmac_laddress\fR specifies a 64-bit \fBI/O\fR address appropriate for
programming the device's \fBDMA\fR engine. If a device has a 64-bit \fBDMA\fR
address register a driver should use this field to program the \fBDMA\fR
engine. \fBdmac_address\fR specifies a 32-bit \fBI/O\fR address. It should be
used for devices that have a 32-bit \fBDMA\fR address register. The \fBI/O\fR
address range that the device can address and other \fBDMA\fR attributes have
to be specified in a \fBddi_dma_attr\fR(9S) structure.
.sp
.LP
\fBdmac_size\fR describes the length of the transfer in bytes.
.sp
.LP
\fBdmac_type\fR contains bus-specific type bits, if appropriate. For example, a
device on a \fBPCI\fR bus has \fBPCI\fR address modifier bits placed here.
.SH SEE ALSO
.sp
.LP
\fBpci\fR(4), \fBsbus\fR(4), \fBsysbus\fR(4),
\fBddi_dma_addr_bind_handle\fR(9F), \fBddi_dma_buf_bind_handle\fR(9F),
\fBddi_dma_getwin\fR(9F), \fBddi_dma_nextcookie\fR(9F), \fBddi_dma_attr\fR(9S)
.sp
.LP
\fIWriting Device Drivers\fR