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

NAME

ldi_ioctl - send an ioctl to a device

SYNOPSIS

#include <sys/sunldi.h>


int ldi_ioctl(ldi_handle_t lh, int cmd, intptr_t arg, int mode,
cred_t *cr, int *rvalp);

PARAMETERS

lh
Layered handle.


cr
Pointer to a credential structure used to open a device.


rvalp
Caller return value. (May be set by driver and is valid only if
the ioctl() succeeds).


cmd
Command argument. Interpreted by driver ioctl() as the operation
to be performed.


arg
Driver parameter. Argument interpretation is driver dependent
and usually depends on the command type.


mode
Bit field that contains:

FKIOCTL
Inform the target device that the ioctl originated
from within the kernel.

DESCRIPTION

The ldi_ioctl() function passes an ioctl request to the device entry
point for the device specified by the layered handle. This operation is
supported for block, character, and streams devices.


If arg is interpreted as a pointer (that is, as not an immediate value)
and the data pointed to by arg is in the kernels address space, the
FKIOCTL flag should be set. This indicates to the target driver that no
data model conversion is necessary.


If the caller of ldi_ioctl() is not the originator of the ioctl data
pointed to by arg, (for example, when passing on an ioctl request from a
user process), the caller must pass on the mode parameter from the
original ioctl. This is because the mode parameter contains the contains
the FMODELS bits that enable the target driver to determine the data
model of the process which originated the ioctl and perform any necessary
conversions. See ddi_model_convert_from(9F) for more information.

STREAM IOCTLS

For a general description of streams ioctls see streamio(4I).
ldi_ioctl() supports a number of streams ioctls, using layered handles in
the place of file descriptors. When issuing streams ioctls the FKIOCTL
parameter should be specified. The possible return values for supported
ioctl commands are also documented in streamio(4I).


The following streams ioctls are supported:

I_PLINK
Behaves as documented in streamio(4I). The layered handle lh
should point to the streams multiplexer. The arg parameter
should point to a layered handle for another streams driver.


I_UNPLINK
Behaves as documented in streamio(4I)). The layered handle
lh should point to the streams multiplexer. The arg
parameter is the multiplexor ID number returned by I_PLINK
when the streams were linked.

RETURN VALUES

The ldi_ioctl() function returns 0 upon success. If a failure occurs
before the request is passed on to the device, possible return values are
shown below. Otherwise any other error number may be returned by the
device.

EINVAL
Invalid input parameters.


ENOTSUP
Operation is not supported for this device.

CONTEXT

These functions can be called from user or kernel context.

SEE ALSO

streamio(4I), ddi_model_convert_from(9F)


June 3, 2003 LDI_IOCTL(9F)