LDI_PROP_LOOKUP_INT_ARRAY(9F) Kernel Functions for Drivers

NAME


ldi_prop_lookup_int_array, ldi_prop_lookup_int64_array,
ldi_prop_lookup_string_array, ldi_prop_lookup_string,
ldi_prop_lookup_byte_array - Lookup property information

SYNOPSIS


#include <sys/sunldi.h>

int ldi_prop_lookup_int_array(ldi_handle_t lh, uint_t flags, char *name,
int **datap, uint_t *nelementsp);


int ldi_prop_lookup_int64_array(ldi_handle_t lh, uint_t flags, char *name,
int64_t **datap, uint_t *nelementsp);


int ldi_prop_lookup_string_array(ldi_handle_t lh, uint_t flags,
char *name, char ***datap, uint_t *nelementsp);


int ldi_prop_lookup_string(ldi_handle_t lh, uint_t flags, char *name,
char **datap);


int ldi_prop_lookup_byte_array(ldi_handle_t lh, uint_t flags, char *name,
uchar_t **datap, uint_t *nelements);


PARAMETERS


lh
Layered handle.


flags
Possible flag values are some combination of:

LDI_DEV_T_ANY
Match the lookup request independent of the
actual dev_t value that was used when the
property was created. The flag indicates
any dev_t value (including DDI_DEV_T_NONE)
associated with a possible property match
will satisfy the matching criteria.


DDI_PROP_DONTPASS
Do not pass request to parent device
information node if the property is not
found.


DDI_PROP_NOTPROM
Do not look at PROM properties (ignored on
platforms that do not support PROM
properties).


name
String containing the property name.


nelements
The address of an unsigned integer which, upon successful
return, contains the number of elements accounted for in the
memory pointed at by datap. Depending on the interface you
use, the elements are either integers, strings or bytes.


datap

ldi_prop_lookup_int_array()

Pointer address to an array of integers which, upon successful
return, point to memory containing the integer array property value.


ldi_prop_lookup_int64_array()

Pointer address to an array of 64-bit integers which, upon successful
return, point to memory containing the integer array property value.


ldi_prop_lookup_string_array()

Pointer address to an array of strings which, upon successful return,
point to memory containing the array of strings. The string array is
formatted as an array of pointers to NULL terminated strings, much
like the argv argument to execve(2).


ldi_prop_lookup_string()

Pointer address to a string which, upon successful return, points to
memory containing the NULL terminated string value of the property.


ldi_prop_lookup_byte_array()

Pointer address to an array of bytes which, upon successful return,
point to memory containing the property byte array value.


INTERFACE LEVEL


illumos DDI specific (illumos DDI).

DESCRIPTION


The property look up functions search for and, if found, return the value
of a given property. Properties are searched for based on the dip and
dev_t values associated with the layered handle, the property name, and
type of the data (integer, string, or byte).


The property search order is as follows:

1. Search software properties created by the driver.

2. Search the software properties created by the system (or nexus
nodes in the device info tree).

3. Search the driver global properties list.

4. If DDI_PROP_NOTPROM is not set, search the PROM properties (if
they exist).

5. If DDI_PROP_DONTPASS is not set, pass this request to the
parent device information node of the device represented by
the layered handle.

6. Return DDI_PROP_NOT_FOUND.


Typically, the specific dev_t value associated with the device
represented by the layered handle (ldi_handle_t) is used as a part of the
property match criteria. This association is handled by the layered
driver infrastructure on behalf of the consumers of the ldi property look
up functions.


However, if the LDI_DEV_T_ANY flag is used, the ldi property lookup
functions match the request regardless of the dev_t value associated with
the property at the time of its creation. If a property was created with
a dev_t set to DDI_DEV_T_NONE, then the only way to look up this property
is with the LDI_DEV_T_ANY flag. PROM properties are always created with a
dev_t set to DDI_DEV_T_NONE.


name must always be set to the name of the property being looked up.


For the ldi_prop_lookup_int_array(), ldi_prop_lookup_int64_array(),
ldi_prop_lookup_string_array(), ldi_prop_lookup_string(), and
ldi_prop_lookup_byte_array() functions, datap is the address of a pointer
which, upon successful return, points to memory containing the value of
the property. In each case *datap points to a different type of property
value. See the individual descriptions of the functions below for details
on the different return values. nelementsp is the address of an unsigned
integer which, upon successful return, contains the number of integer,
string or byte elements accounted for in the memory pointed at by *datap.


All of the property look up functions may block to allocate memory needed
to hold the value of the property.


When a driver has obtained a property with any look up function and is
finished with that property, it must be freed by call ddi_prop_free().
ddi_prop_free() must be called with the address of the allocated
property. For instance, if you call ldi_prop_lookup_int_array() with
datap set to the address of a pointer to an integer, &my-int-ptr, the
companion free call is ddi_prop_free(my-int-ptr).


Property look up functions are described below:

ldi_prop_lookup_int_array()

This function searches for and returns an array of integer property
values. An array of integers is defined to *nelementsp number of 4
byte long integer elements. datap should be set to the address of a
pointer to an array of integers which, upon successful return, will
point to memory containing the integer array value of the property.


ldi_prop_lookup_int64_array()

This function searches for and returns an array of integer property
values. An array of integers is defined to *nelementsp number of 8
byte long integer elements. datap should be set to the address of a
pointer to an array of integers which, upon successful return, will
point to memory containing the integer array value of the property
This function does not search the PROM for 64-bit property values.


ldi_prop_lookup_string_array()

This function searches for and returns a property that is an array of
strings. datap should be set to an address of a pointer to an array
of strings which, upon successful return, will point to memory
containing the array of strings. The array of strings is formatted
as an array of pointers to null-terminated strings, much like the
argv argument to execve(2).


ldi_prop_lookup_string()

This function searches for and returns a property that is a null-
terminated string. datap should be set to the address of a pointer to
a string which, upon successful return, points to memory containing
the string value of the property.


ldi_prop_lookup_byte_array()

This function searches for and returns a property that is an array of
bytes. datap should be set to the address of a pointer to an array
of bytes which, upon successful return, points to memory
containing the byte array value of the property.


ddi_prop_free()

Frees the resources associated with a property previously
allocated using ldi_prop_lookup_int_array(),
ldi_prop_lookup_int64_array(), ldi_prop_lookup_string_array(),
ldi_prop_lookup_string(), and ldi_prop_lookup_byte_array().


RETURN VALUES


The functions ldi_prop_lookup_int_array(), ldi_prop_lookup_int64_array(),
ldi_prop_lookup_string_array(), ldi_prop_lookup_string(), and
ldi_prop_lookup_byte_array() return the following values:

DDI_PROP_SUCCESS
Property found and returned.


DDI_PROP_INVAL_ARG
If an attempt is made to look up a property
with a NULL ldi handle, name is NULL or name is
a the null string.


DDI_PROP_NOT_FOUND
Property not found.


DDI_PROP_UNDEFINED
Prop explicitly undefined (see
ddi_prop_undefine(9F)).


DDI_PROP_CANNOT_DECODE
Property value cannot be decoded.


CONTEXT


These functions may be called from user or kernel context.

EXAMPLE


Using ldi_prop_lookup_int64_array().

The following example demonstrates the use of
ldi_prop_lookup_int64_array().


int64_t *options;
uint_t noptions;

/*
* Get the data associated with the integer "options" property
* array, along with the number of option integers
*/

if (ldi_prop_lookup_int64_array(lh,
LDI_DEV_T_ANY|DDI_PROP_NOTPROM, "options",
&options, &noptions) == DDI_PROP_SUCCESS) {
/*
* Process the options data from the property
* we just received. Let's do "our thing" with data.
*/
xx_process_options(options, noptions);

/*
* Free the memory allocated for the property data
*/
ddi_prop_free(options);
}


SEE ALSO


execve(2), ddi_prop_free(9F), ddi_prop_lookup(9F), ldi_prop_exists(9F) .


Writing Device Drivers

illumos June 3, 2003 LDI_PROP_LOOKUP_INT_ARRAY(9F)