Tribblix: manual page: ddi

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

NAME

ddi_segmap, ddi_segmap_setup - set up a user mapping using seg_dev

SYNOPSIS

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

int ddi_segmap(dev_t dev, off_t offset, struct as *asp,
caddr_t *addrp, off_t len, uint_t prot,
uint_t maxprot, uint_t flags, cred_t *credp);

int ddi_segmap_setup(dev_t dev, off_t offset, struct as *asp,
caddr_t *addrp, off_t len, uint_t prot,
uint_t maxprot, uint_t flags, cred_t *credp,
const ddi_device_acc_attr_t *accattrp, uint_t rnumber);

INTERFACE LEVEL

These interfaces are obsolete. See devmap(9E) for an alternative to
ddi_segmap(). Use devmap_setup(9F) instead of ddi_segmap_setup().

PARAMETERS

dev
The device whose memory is to be mapped.

offset
The offset within device memory at which the mapping
begins.

asp
An opaque pointer to the user address space into which
the device memory should be mapped.

addrp
Pointer to the starting address within the user address
space to which the device memory should be mapped.

len
Length (in bytes) of the memory to be mapped.

prot
A bit field that specifies the protections. Some
combinations of possible settings are:

PROT_READ
Read access is desired.

PROT_WRITE
Write access is desired.

PROT_EXEC
Execute access is desired.

PROT_USER
User-level access is desired (the mapping
is being done as a result of a mmap(2)
system call).

PROT_ALL
All access is desired.

maxprot
Maximum protection flag possible for attempted mapping
(the PROT_WRITE bit may be masked out if the user opened
the special file read-only). If (maxprot & prot) != prot
then there is an access violation.

flags
Flags indicating type of mapping. Possible values are
(other bits may be set):

MAP_PRIVATE
Changes are private.

MAP_SHARED
Changes should be shared.

MAP_FIXED
The user specified an address in *addrp
rather than letting the system pick and
address.

credp
Pointer to user credential structure.

ddi_segmap_setup()
dev_acc_attr
Pointer to a ddi_device_acc_attr(9S) structure which
contains the device access attributes to apply to
this mapping.

rnumber
Index number to the register address space set.

DESCRIPTION

Future releases of Solaris will provide this function for binary and
source compatibility. However, for increased functionality, use
ddi_devmap_segmap(9F) instead. See ddi_devmap_segmap(9F) for
details.

ddi_segmap() and ddi_segmap_setup() set up user mappings to device
space. When setting up the mapping, the ddi_segmap() and
ddi_segmap_setup() routines call the mmap(9E) entry point to validate
the range to be mapped. When a user process accesses the mapping,
the drivers mmap(9E) entry point is again called to retrieve the page
frame number that needs to be loaded. The mapping translations for
that page are then loaded on behalf of the driver by the DDI
framework.

ddi_segmap() is typically used as the segmap(9E) entry in the
cb_ops(9S) structure for those devices that do not choose to provide
their own segmap(9E) entry point. However, some drivers may have
their own segmap(9E) entry point to do some initial processing on the
parameters and then call ddi_segmap() to establish the default memory
mapping.

ddi_segmap_setup() is used in the drivers segmap(9E) entry point to
set up the mapping and assign device access attributes to that
mapping. rnumber specifies the register set representing the range
of device memory being mapped. See ddi_device_acc_attr(9S) for
details regarding what device access attributes are available.

ddi_segmap_setup() cannot be used directly in the cb_ops(9S)
structure and requires a driver to have a segmap(9E) entry point.

RETURN VALUES

ddi_segmap() and ddi_segmap_setup() return the following values:

0
Successful completion.

Non-zero
An error occurred. In particular, they return ENXIO if
the range to be mapped is invalid.

CONTEXT

ddi_segmap() and ddi_segmap_setup() can be called from user or kernel
context only.

ATTRIBUTES