ddi_devid_compare(9F) Kernel Functions for Drivers ddi_devid_compare(9F)NAME
ddi_devid_compare, ddi_devid_free, ddi_devid_init, ddi_devid_register,
ddi_devid_sizeof, ddi_devid_str_decode, ddi_devid_str_encode,
ddi_devid_str_free, ddi_devid_get, ddi_devid_unregister,
ddi_devid_valid - kernel interfaces for device ids
SYNOPSIS
int ddi_devid_compare(ddi_devid_t devid1, ddi_devid_t devid2);
size_t ddi_devid_sizeof(ddi_devid_t devid);
int ddi_devid_init(dev_info_t *dip, ushort_t devid_type,
ushort_t nbytes, void *id, ddi_devid_t *retdevid);
void ddi_devid_free(ddi_devid_t devid);
int ddi_devid_register(dev_info_t *dip, ddi_devid_t devid);
int ddi_devid_str_decode(char *devidstr, ddi_devid_t *retdevid,
char **retminor_name);
int ddi_devid_str_encode(ddi_devid_t devid, char *minor_name);
int ddi_devid_str_free(char *devidstr);
int ddi_devid_get(dev_info_t *dip, ddi_devid_t *retdevid);
void ddi_devid_unregister(dev_info_t *dip);
int ddi_devid_valid(ddi_devid_t devid);
PARAMETERS
devid The device id address.
devidstr The devid and minor_name represented as a string.
devid1 The first of two device id addresses to be compared call‐
ing ddi_devid_compare().
devid2 The second of two device id addresses to be compared
calling ddi_devid_compare().
dip A dev_info pointer, which identifies the device.
devid_type The following device id types may be accepted by the
ddi_devid_init() function:
DEVID_SCSI3_WWN World Wide Name associated with
SCSI-3 devices.
DEVID_SCSI_SERIAL Vendor IDand serial number associ‐
ated with a SCSI device. Note: This
may only be used if known to be
unique; otherwise a fabricated
device id must be used.
DEVID_ENCAP Device ID of another device. This is
for layered device driver usage.
DEVID_FAB Fabricated device ID.
minor_name The minor name to be encoded.
nbytes The length in bytes of device ID.
retdevid The return address of the device ID.
retminor_name The return address of a minor name. Free string with
ddi_devid_str_free().
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI).
DESCRIPTION
The following routines are used to provide unique identifiers, device
IDs, for devices. Specifically, kernel modules use these interfaces to
identify and locate devices, independent of the device's physical con‐
nection or its logical device name or number.
ddi_devid_compare() compares two device IDs byte-by-byte and determines
both equality and sort order.
ddi_devid_sizeof() returns the number of bytes allocated for the passed
in device ID (devid).
ddi_devid_init() allocates memory and initializes the opaque device ID
structure. This function does not store the devid. If the device id is
not derived from the device's firmware, it is the driver's responsibil‐
ity to store the devid on some reliable store. When a devid_type of
either DEVID_SCSI3_WWN, DEVID_SCSI_SERIAL, or DEVID_ENCAP is accepted,
an array of bytes (id) must be passed in (nbytes).
When the devid_type DEVID_FAB is used, the array of bytes (id) must be
NULL and the length (nbytes) must be zero. The fabricated device ids,
DEVID_FAB will be initialized with the machine's host id and a time‐
stamp.
Drivers must free the memory allocated by this function, using the
ddi_devid_free() function.
ddi_devid_free() frees the memory allocated for the returned devid by
the ddi_devid_init() and devid_str_decode() functions.
ddi_devid_register() registers the device ID address (devid) with the
DDI framework, associating it with the dev_info passed in (dip). The
drivers must register device IDs at attach time. See attach(9E).
ddi_devid_unregister() removes the device ID address from the dev_info
passed in (dip). Drivers must use this function to unregister the
device ID when devices are being detached. This function does not free
the space allocated for the device ID. The driver must free the space
allocated for the device ID, using the ddi_devid_free() function. See
detach(9E).
ddi_devid_valid() validates the device ID (devid) passed in. The driver
must use this function to validate any fabricated device ID that has
been stored on a device.
ddi_devid_get() returns a pointer to the device ID structure through
retdevid if there is already a registered device ID associated with the
dev_info node. A driver can use this interface to check and get the
device ID associated with the dev_info node. If no device ID is regis‐
tered for the node then it returns DDI_FAILURE.
The ddi_devid_str_encode() function encodes a devid and minor_name into
a null-terminated ASCII string, returning a pointer to that string. If
both a devid and a minor_name are non-null, then a slash (/) is used to
separate the devid from the minor_name in the encoded string. If
minor_name is null, then only the devid is encoded. If the devid is
null, then the special string id0 is returned. Note that you cannot
compare the returned string against another string with strcmp() to
determine devid equality. The returned string must be freed by calling
devid_str_free().
The ddi_devid_str_decode() function takes a string previously produced
by the devid_str_encode(3DEVID) or ddi_devid_str_encode() function and
decodes the contained device ID and minor_name, allocating and return‐
ing pointers to the extracted parts through the retdevid and retmi‐
nor_name arguments. If the special devidstr id0 was specified then the
returned device ID and minor name will both be null. A non-null
returned devid must be freed by the caller through the ddi_devid_free()
function. A non-null returned minor name must be freed by calling
ddi_devid_str_free().
The ddi_devid_str_free() function is used to free all strings returned
by the ddi_devid functions (the ddi_devid_str_encode() function return
value and the returned retminor_name argument).
RETURN VALUESddi_devid_init() returns the following values:
DDI_SUCCESS Success.
DDI_FAILURE Out of memory. An invalid devid_type was passed in.
ddi_devid_valid() returns the following values:
DDI_SUCCESS Valid device ID.
DDI_FAILURE Invalid device ID.
ddi_devid_register() returns the following values:
DDI_SUCCESS Success.
DDI_FAILURE Failure. The device ID is already registered or the
device ID is invalid.
ddi_devid_valid() returns the following values:
DDI_SUCCESS Valid device ID.
DDI_FAILURE Invalid device ID.
ddi_devid_get() returns the following values:
DDI_SUCCESS Device ID is present and a pointer to it is
returned in retdevid.
DDI_FAILURE No device ID is defined for this dev_info node.
ddi_devid_compare() returns the following values:
−1 The first device ID is less than the second device ID.
0 The first device ID is equal to the second device ID.
1 The first device ID is greater than the second device ID.
ddi_devid_sizeof() returns the size of the devid in bytes. If called
with a null, then the number of bytes that must be allocated and ini‐
tialized to determine the size of a complete device ID is returned.
ddi_devid_str_encode() returns a value of null to indicate failure.
Failure can be caused by attempting to encode an invalid devid. If the
return value is non-null then the caller must free the returned string
by using the devid_str_free() function.
ddi_devid_str_decode() returns the following values:
DDI_SUCCESS Success.
DDI_FAILURE Failure; the devidstr string was not valid.
CONTEXT
These functions can be called from a user or kernel context.
SEE ALSOdevid_get(3DEVID), , libdevid(3LIB), attributes(5), attach(9E),
detach(9E), kmem_free(9F)SunOS 5.10 18 Sep 2007 ddi_devid_compare(9F)
