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)