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, 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 spe‐
cial 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 let‐
ting 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 VALUESddi_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.
CONTEXTddi_segmap() and ddi_segmap_setup() can be called from user or kernel
context only.
ATTRIBUTES
See attributes(5) for a description of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Stability Level │Obsolete │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOmmap(2), attributes(5), devmap(9E), mmap(9E), segmap(9E), devmap_set‐
up(9F), cb_ops(9S), ddi_device_acc_attr(9S)
Writing Device Drivers
SunOS 5.10 17 Nov 2003 ddi_segmap(9F)