ddi_mapdev - create driver-controlled mapping of device

---

SYNOPSIS

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

int ddi_mapdev(dev_t dev, off_t offset, struct as *asp, caddr_t *addrp, off_t len,
          u_int prot, u_int maxprot, u_int flags, cred_t *cred, struct ddi_mapdev_ctl *ctl,
          ddi_mapdev_handle_t *handlep, void *devprivate);

INTERFACE LEVEL

ARGUMENTS

dev

The device whose memory is to be mapped.

offset

The offset within device memory at which the mapping begins.

as

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.

maxprot

Maximum protection flag possible for attempted mapping.

flags

Flags indicating type of mapping.

cred

Pointer to the user credentials structure.

ctl

A pointer to a ddi_mapdev_ctl.9s structure. The structure contains pointers to device driver-supplied functions that manage events on the device mapping.

handlep

An opaque pointer to a device mapping handle. A handle to the new device mapping is generated and placed into the location pointed to by *handlep. If the call fails, the value of *handlep is undefined.

devprivate

Driver private mapping data. This value is passed into each mapping call back routine.

DESCRIPTION

The user events that the driver is notified of are:

access

User has accessed an address in the mapping that has no translations.

duplication

User has duplicated the mapping. Mappings are duplicated when the process calls fork.2

unmapping

User has called munmap.2 on the mapping or is exiting.

See mapdev_access.9e mapdev_dup.9e and mapdev_free.9e for details on these entry points.

The range to be mapped, defined by offset and len must be valid.

The arguments dev, asp, addrp, len, prot, maxprot, flags, and cred are provided by the segmap.9e entry point and should not be modified. See segmap.9e for a description of these arguments. Unlike ddi_segmap.9f the drivers mmap.9e entry point is not called to verify the range to be mapped.

With the handle, device drivers can use ddi_mapdev_intercept.9f and ddi_mapdev_nointercept.9f to inform the system of whether or not they are interested in being notified when the user process accesses the mapping. By default, user accesses to newly created mappings will generate a call to the mapdev_access() entry point. The driver is always notified of duplications and unmaps.

The device may also use the handle to assign certain characteristics to the mapping. See ddi_mapdev_set_device_acc_attr.9f for details.

The device driver can use these interfaces to implement a device context and control user accesses to the device space. ddi_mapdev() is typically called from the segmap.9e entry point.

RETURN VALUES

ddi_mapdev() returns zero on success and non-zero on failure. The return value from ddi_mapdev() should be used as the return value for the drivers segmap() entry point.

CONTEXT

This routine can be called from user or kernel context only.

SEE ALSO

NOTES

Created by unroff & hp-tools. © by Hans-Peter Bischof. All Rights Reserved (1997).

Last modified 21/April/97