xref: /freebsd/lib/libdevinfo/devinfo.3 (revision 6780ab54325a71e7e70112b11657973edde8655e)
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2.\" Copyright (c) 2001 Michael Smith <msmith@FreeBSD.org>
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26.\" $FreeBSD$
27.\"
28.Dd April 19, 2001
29.Dt DEVINFO 3
30.Os
31.Sh NAME
32.Nm devinfo ,
33.Nm devinfo_init ,
34.Nm devinfo_free ,
35.Nm devinfo_handle_to_device ,
36.Nm devinfo_handle_to_resource ,
37.Nm devinfo_handle_to_rman ,
38.Nm devinfo_foreach_device_child ,
39.Nm devinfo_foreach_device_resource ,
40.Nm devinfo_foreach_rman_resource ,
41.Nm devinfo_foreach_rman
42.Nd device and resource information utility library
43.Sh LIBRARY
44.Lb libdevinfo
45.Sh SYNOPSIS
46.In devinfo.h
47.Ft int
48.Fn devinfo_init "void"
49.Ft void
50.Fn devinfo_free "void"
51.Ft struct devinfo_dev *
52.Fn devinfo_handle_to_device "devinfo_handle_t handle"
53.Ft struct devinfo_res *
54.Fn devinfo_handle_to_resource "devinfo_handle_t handle"
55.Ft struct devinfo_rman *
56.Fn devinfo_handle_to_rman "devinfo_handle_t handle"
57.Ft int
58.Fo devinfo_foreach_device_child
59.Fa "struct devinfo_dev *parent"
60.Fa "int \*[lp]*fn\*[rp]\*[lp]struct devinfo_dev *child, void *arg\*[rp]"
61.Fa "void *arg"
62.Fc
63.Ft int
64.Fo devinfo_foreach_device_resource
65.Fa "struct devinfo_dev *dev"
66.Fa "int \*[lp]*fn\*[rp]\*[lp]struct devinfo_dev *dev, struct devinfo_res *res, void *arg\*[rp]"
67.Fa "void *arg"
68.Fc
69.Ft int
70.Fo devinfo_foreach_rman_resource
71.Fa "struct devinfo_rman *rman"
72.Fa "int \*[lp]*fn\*[rp]\*[lp]struct devinfo_res *res, void *arg\*[rp]"
73.Fa "void *arg"
74.Fc
75.Ft int
76.Fo devinfo_foreach_rman
77.Fa "int \*[lp]*fn\*[rp]\*[lp]struct devinfo_rman *rman, void *arg\*[rp]"
78.Fa "void *arg"
79.Fc
80.Sh DESCRIPTION
81The
82.Nm
83library provides access to the kernel's internal device hierarchy
84and to the I/O resource manager.
85The library uses a
86.Xr sysctl 3
87interface to obtain a snapshot of the kernel's state,
88which is then made available to the application.
89.Pp
90Due to the fact that the information may be logically arranged
91in a number of different fashions,
92the library does not attempt to impose any structure on the data.
93.Pp
94Device, resource, and resource manager information is returned in
95data structures defined in
96.Aq Pa devinfo.h :
97.Bd -literal -offset indent
98struct devinfo_dev {
99    devinfo_handle_t	dd_handle;	/* device handle */
100    devinfo_handle_t	dd_parent;	/* parent handle */
101    char		*dd_name;	/* name of device */
102    char		*dd_desc;	/* device description */
103    char		*dd_drivername;	/* name of attached driver */
104    char		*dd_pnpinfo;	/* pnp info from parent bus */
105    char		*dd_location;	/* Where bus thinks dev at */
106    uint32_t		dd_devflags;	/* API flags */
107    uint16_t		dd_flags;	/* internal dev flags */
108    device_state_t	dd_state;	/* attachment state of dev */
109};
110
111struct devinfo_rman {
112    devinfo_handle_t	dm_handle;	/* resource manager handle */
113    u_long		dm_start;	/* resource start */
114    u_long		dm_size;	/* resource size */
115    char		*dm_desc;	/* resource description */
116};
117
118struct devinfo_res {
119    devinfo_handle_t	dr_handle;	/* resource handle */
120    devinfo_handle_t	dr_rman;	/* resource manager handle */
121    devinfo_handle_t	dr_device;	/* owning device */
122    u_long		dr_start;	/* region start */
123    u_long		dr_size;	/* region size */
124};
125.Ed
126.Pp
127The
128.Vt devinfo_handle_t
129values can be used to look up the correspondingly referenced structures.
130.Pp
131.Fn devinfo_init
132takes a snapshot of the kernel's internal device and resource state.
133It returns nonzero
134if after a number of retries a consistent snapshot cannot be obtained.
135.Fn devinfo_init
136must be called before any other functions can be used.
137.Pp
138.Fn devinfo_free
139releases the memory associated with the snapshot.
140Any pointers returned by other functions are invalidated by this,
141and
142.Fn devinfo_init
143must be called again before using any other functions.
144.Pp
145.Fn devinfo_handle_to_device ,
146.Fn devinfo_handle_to_resource
147and
148.Fn devinfo_handle_to_rman
149return pointers to
150.Vt devinfo_dev ,
151.Vt devinfo_res
152and
153.Vt devinfo_rman
154structures respectively based on the
155.Vt devinfo_handle_t
156passed to them.
157These functions can be used to traverse the tree from any node to any
158other node.
159If
160.Fn devinfo_handle_to_device
161is passed the constant
162.Dv DEVINFO_ROOT_DEVICE
163it will return the handle to the root of the device tree.
164.Pp
165.Fn devinfo_foreach_device_child
166invokes its callback argument
167.Fa fn
168on every device which is an immediate child of
169.Fa device .
170.Fa fn
171is also passed
172.Fa arg ,
173allowing state to be passed to the callback function.
174If
175.Fa fn
176returns a nonzero error value the traversal is halted,
177and
178.Fn devinfo_foreach_device_child
179returns the error value to its caller.
180.Pp
181.Fn devinfo_foreach_device_resource
182invokes its callback argument
183.Fa fn
184on every resource which is owned by
185.Fa device .
186.Fa fn
187is also passed
188.Fa device
189and
190.Fa arg ,
191allowing state to be passed to the callback function.
192If
193.Fa fn
194returns a nonzero error value the traversal is halted,
195and
196.Fn devinfo_foreach_device_resource
197returns the error value to its caller.
198.Pp
199.Fn devinfo_foreach_rman_resource
200invokes its callback argument
201.Fa fn
202on every resource within the resource manager
203.Fa rman .
204.Fa fn
205is also passed
206.Fa arg ,
207allowing state to be passed to the callback function.
208If
209.Fa fn
210returns a nonzero error value the traversal is halted,
211and
212.Fn devinfo_foreach_rman_resource
213returns the error value to its caller.
214.Pp
215.Fn devinfo_foreach_rman
216invokes its callback argument
217.Fa fn
218on every resource manager.
219.Fa fn
220is also passed
221.Fa arg ,
222allowing state to be passed to the callback function.
223If
224.Fa fn
225returns a nonzero error value the traversal is halted,
226and
227.Fn devinfo_foreach_rman
228returns the error value to its caller.
229.Sh SEE ALSO
230.Xr devstat 3
231.Sh HISTORY
232The
233.Nm
234library first appeared in
235.Fx 5.0 .
236.Sh AUTHORS
237.An Michael Smith Aq msmith@FreeBSD.org
238.Sh BUGS
239This is the first implementation of the library,
240and the interface is still subject to refinement.
241.Pp
242The interface does not report device classes or drivers,
243making it hard to sort by class or driver.
244