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DEVINFO(3) FreeBSD Library Functions Manual DEVINFO(3)
NAME
devinfo, devinfo_init, devinfo_free, devinfo_handle_to_device,
devinfo_handle_to_resource, devinfo_handle_to_rman,
devinfo_foreach_device_child, devinfo_foreach_device_resource,
devinfo_foreach_rman_resource, devinfo_foreach_rman - device and resource
information utility library
LIBRARY
Device and Resource Information Utility Library (libdevinfo, -ldevinfo)
SYNOPSIS
#include <devinfo.h>
int
devinfo_init(void);
void
devinfo_free(void);
struct devinfo_dev *
devinfo_handle_to_device(devinfo_handle_t handle);
struct devinfo_res *
devinfo_handle_to_resource(devinfo_handle_t handle);
struct devinfo_rman *
devinfo_handle_to_rman(devinfo_handle_t handle);
int
devinfo_foreach_device_child(struct devinfo_dev *parent,
int (*fn)(struct devinfo_dev *child, void *arg), void *arg);
int
devinfo_foreach_device_resource(struct devinfo_dev *dev,
int (*fn)(struct devinfo_dev *dev,
struct devinfo_res *res, void *arg), void *arg);
int
devinfo_foreach_rman_resource(struct devinfo_rman *rman,
int (*fn)(struct devinfo_res *res, void *arg), void *arg);
int
devinfo_foreach_rman(int (*fn)(struct devinfo_rman *rman, void *arg),
void *arg);
DESCRIPTION
The devinfo library provides access to the kernel's internal device
hierarchy and to the I/O resource manager. The library uses a sysctl(3)
interface to obtain a snapshot of the kernel's state, which is then made
available to the application.
Due to the fact that the information may be logically arranged in a
number of different fashions, the library does not attempt to impose any
structure on the data.
Device, resource, and resource manager information is returned in data
structures defined in <devinfo.h>:
char *dd_pnpinfo; /* pnp info from parent bus */
char *dd_location; /* Where bus thinks dev at */
uint32_t dd_devflags; /* API flags */
uint16_t dd_flags; /* internal dev flags */
device_state_t dd_state; /* attachment state of dev */
};
struct devinfo_rman {
devinfo_handle_t dm_handle; /* resource manager handle */
rman_res_t dm_start; /* resource start */
rman_res_t dm_size; /* resource size */
char *dm_desc; /* resource description */
};
struct devinfo_res {
devinfo_handle_t dr_handle; /* resource handle */
devinfo_handle_t dr_rman; /* resource manager handle */
devinfo_handle_t dr_device; /* owning device */
rman_res_t dr_start; /* region start */
rman_res_t dr_size; /* region size */
};
The devinfo_handle_t values can be used to look up the correspondingly
referenced structures.
devinfo_init() takes a snapshot of the kernel's internal device and
resource state. It returns nonzero if after a number of retries a
consistent snapshot cannot be obtained. devinfo_init() must be called
before any other functions can be used.
devinfo_free() releases the memory associated with the snapshot. Any
pointers returned by other functions are invalidated by this, and
devinfo_init() must be called again before using any other functions.
devinfo_handle_to_device(), devinfo_handle_to_resource() and
devinfo_handle_to_rman() return pointers to devinfo_dev, devinfo_res and
devinfo_rman structures respectively based on the devinfo_handle_t passed
to them. These functions can be used to traverse the tree from any node
to any other node. If devinfo_handle_to_device() is passed the constant
DEVINFO_ROOT_DEVICE it will return the handle to the root of the device
tree.
devinfo_foreach_device_child() invokes its callback argument fn on every
device which is an immediate child of device. The fn function is also
passed arg, allowing state to be passed to the callback function. If fn
returns a nonzero error value the traversal is halted, and
devinfo_foreach_device_child() returns the error value to its caller.
devinfo_foreach_device_resource() invokes its callback argument fn on
every resource which is owned by device. The fn function is also passed
device and arg, allowing state to be passed to the callback function. If
fn returns a nonzero error value the traversal is halted, and
devinfo_foreach_device_resource() returns the error value to its caller.
devinfo_foreach_rman_resource() invokes its callback argument fn on every
resource within the resource manager rman. The fn function is also
passed arg, allowing state to be passed to the callback function. If fn
returns a nonzero error value the traversal is halted, and
devinfo_foreach_rman_resource() returns the error value to its caller.
SEE ALSO
devstat(3)
HISTORY
The devinfo library first appeared in FreeBSD 5.0.
AUTHORS
Michael Smith <msmith@FreeBSD.org>
BUGS
This is the first implementation of the library, and the interface is
still subject to refinement.
The interface does not report device classes or drivers, making it hard
to sort by class or driver.
FreeBSD 14.0-RELEASE-p11 April 19, 2001 FreeBSD 14.0-RELEASE-p11