path: root/usr/src/man/man9f/devmap_setup.9f

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.TH devmap_setup 9F "22 Jan 1997" "SunOS 5.11" "Kernel Functions for Drivers"
.SH NAME
devmap_setup, ddi_devmap_segmap \- set up a user mapping to device memory using
the devmap framework
.SH SYNOPSIS
.LP
.nf
#include <sys/ddi.h> 
#include <sys/sunddi.h> 



\fBint\fR \fBdevmap_setup\fR(\fBdev_t\fR \fIdev\fR, \fBoffset_t\fR \fIoff\fR, \fBddi_as_handle_t\fR \fIas\fR, 
     \fBcaddr_t *\fR\fIaddrp\fR, \fBsize_t\fR\fIlen\fR, \fBuint_t\fR \fIprot\fR, \fBuint_t\fR \fImaxprot\fR, 
     \fBuint_t\fR \fIflags\fR, \fBcred_t *\fR\fIcred\fR);
.fi

.LP
.nf
\fBint\fR \fBddi_devmap_segmap\fR(\fBdev_t\fR \fIdev\fR, \fBoff_t\fR \fIoff\fR, \fBddi_as_handle_t\fR \fIas\fR, 
     \fBcaddr_t *\fR\fIaddrp\fR, \fBoff_t\fR\fIlen\fR, \fBuint_t\fR \fIprot\fR, \fBuint_t\fR \fImaxprot\fR, 
     \fBuint_t\fR \fIflags\fR, \fBcred_t *\fR\fIcred\fR);
.fi

.SH INTERFACE LEVEL
.sp
.LP
Solaris DDI specific (Solaris DDI).
.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIdev\fR \fR
.ad
.RS 12n
.rt  
Device whose memory is to be mapped.
.RE

.sp
.ne 2
.mk
.na
\fB\fIoff\fR \fR
.ad
.RS 12n
.rt  
User offset within the logical device memory at which the mapping begins.
.RE

.sp
.ne 2
.mk
.na
\fB\fIas\fR \fR
.ad
.RS 12n
.rt  
An opaque data structure that describes the address space into which the device
memory should be mapped.
.RE

.sp
.ne 2
.mk
.na
\fB\fIaddrp\fR \fR
.ad
.RS 12n
.rt  
Pointer to the starting address in the address space into which the device
memory should be mapped.
.RE

.sp
.ne 2
.mk
.na
\fB\fIlen\fR \fR
.ad
.RS 12n
.rt  
Length (in bytes) of the memory to be mapped.
.RE

.sp
.ne 2
.mk
.na
\fB\fIprot\fR \fR
.ad
.RS 12n
.rt  
A bit field that specifies the protections. Some possible settings combinations
are:
.sp
.ne 2
.mk
.na
\fB\fBPROT_READ\fR \fR
.ad
.RS 15n
.rt  
Read access is desired.
.RE

.sp
.ne 2
.mk
.na
\fB\fBPROT_WRITE\fR \fR
.ad
.RS 15n
.rt  
Write access is desired.
.RE

.sp
.ne 2
.mk
.na
\fB\fBPROT_EXEC\fR \fR
.ad
.RS 15n
.rt  
Execute access is desired.
.RE

.sp
.ne 2
.mk
.na
\fB\fBPROT_USER\fR \fR
.ad
.RS 15n
.rt  
User-level access is desired (the mapping is being done as a result of a
\fBmmap\fR(2) system call).
.RE

.sp
.ne 2
.mk
.na
\fB\fBPROT_ALL\fR \fR
.ad
.RS 15n
.rt  
All access is desired.
.RE

.RE

.sp
.ne 2
.mk
.na
\fB\fImaxprot\fR \fR
.ad
.RS 12n
.rt  
Maximum protection flag possible for attempted mapping; the \fBPROT_WRITE\fR
bit may be masked out if the user opened the special file read-only.
.RE

.sp
.ne 2
.mk
.na
\fB\fIflags\fR \fR
.ad
.RS 12n
.rt  
Flags indicating type of mapping. The following flags can be specified:
.sp
.ne 2
.mk
.na
\fB\fBMAP_PRIVATE\fR \fR
.ad
.RS 16n
.rt  
Changes are private.
.RE

.sp
.ne 2
.mk
.na
\fB\fBMAP_SHARED\fR \fR
.ad
.RS 16n
.rt  
Changes should be shared.
.RE

.sp
.ne 2
.mk
.na
\fB\fBMAP_FIXED\fR \fR
.ad
.RS 16n
.rt  
The user specified an address in  \fI*addrp\fR rather than letting the system
choose an address.
.RE

.RE

.sp
.ne 2
.mk
.na
\fB\fIcred\fR \fR
.ad
.RS 12n
.rt  
Pointer to the user credential structure.
.RE

.SH DESCRIPTION
.sp
.LP
\fBdevmap_setup()\fR and \fBddi_devmap_segmap()\fR allow device drivers to use
the devmap framework to set up user mappings to device memory.  The devmap
framework provides several advantages over the default device mapping framework
that is used by \fBddi_segmap\fR(9F) or \fBddi_segmap_setup\fR(9F). Device
drivers should use the devmap framework, if the driver wants to:
.RS +4
.TP
.ie t \(bu
.el o
use an optimal MMU pagesize to minimize address translations,
.RE
.RS +4
.TP
.ie t \(bu
.el o
conserve kernel resources,
.RE
.RS +4
.TP
.ie t \(bu
.el o
receive callbacks to manage events on the mapping,
.RE
.RS +4
.TP
.ie t \(bu
.el o
export kernel memory to applications,
.RE
.RS +4
.TP
.ie t \(bu
.el o
set up device contexts for the user mapping if the device requires context
switching,
.RE
.RS +4
.TP
.ie t \(bu
.el o
assign device access attributes to the user mapping, or
.RE
.RS +4
.TP
.ie t \(bu
.el o
change the maximum protection for the mapping.
.RE
.sp
.LP
\fBdevmap_setup()\fR must be called in the \fBsegmap\fR(9E) entry point to
establish the mapping for the application. \fBddi_devmap_segmap()\fR can be
called in, or be used as, the \fBsegmap\fR(9E) entry point. The differences
between  \fBdevmap_setup()\fR and \fBddi_devmap_segmap()\fR are in the data
type used for \fIoff\fR and \fIlen\fR.
.sp
.LP
When setting up the mapping,  \fBdevmap_setup()\fR and
\fBddi_devmap_segmap()\fR call the \fBdevmap\fR(9E) entry point to validate the
range to be mapped. The \fBdevmap\fR(9E) entry point also translates the
logical offset (as seen by the application) to the corresponding physical
offset within the device address space. If the driver does not provide its own
\fBdevmap\fR(9E) entry point, \fBEINVAL\fR will be returned to the
\fBmmap\fR(2) system call.
.SH RETURN VALUES
.sp
.ne 2
.mk
.na
\fB\fB0\fR \fR
.ad
.RS 12n
.rt  
Successful completion.
.RE

.sp
.ne 2
.mk
.na
\fB\fBNon-zero\fR\fR
.ad
.RS 12n
.rt  
An error occurred.  The return value of \fBdevmap_setup()\fR and
\fBddi_devmap_segmap()\fR should be used directly in the  \fBsegmap\fR(9E)
entry point.
.RE

.SH CONTEXT
.sp
.LP
\fBdevmap_setup()\fR and \fBddi_devmap_segmap()\fR can be called from user or
kernel context only.
.SH SEE ALSO
.sp
.LP
\fBmmap\fR(2), \fBdevmap\fR(9E), \fBsegmap\fR(9E), \fBddi_segmap\fR(9F),
\fBddi_segmap_setup\fR(9F), \fBcb_ops\fR(9S)
.sp
.LP
\fIWriting Device Drivers\fR