te
Copyright (c) 2009, Sun Microsystems, Inc. All Rights Reserved
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License. You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions and limitations under the License. When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with
the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
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

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);

devid devidstr devid1 devid2 dip devid_type minor_name nbytes retdevid retminor_name illumos DDI specific (illumos DDI). 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 connection 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 responsibility 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 timestamp.

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.

The ddi_devid_get() function 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. It returns DDI_FAILURE if no device ID is registered for the node.

The ddi_devid_get() function allocates memory for the opaque device ID structure and initializes it with the associated device ID and returns the pointer to it. The driver must free the memory allocated by this function using the ddi_devid_free() function.

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 returning pointers to the extracted parts through the retdevid and retminor_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).

ddi_devid_init() returns the following values:

ddi_devid_valid() returns the following values:

ddi_devid_register() returns the following values:

ddi_devid_valid() returns the following values:

ddi_devid_get() returns the following values:

ddi_devid_compare() returns the following values:

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 initialized 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:

These functions can be called from a user or kernel context. devid_get (3DEVID), libdevid (3LIB), attributes (7), attach (9E), detach (9E), kmem_free (9F)

Writing Device Drivers