1 .\" Copyright (c) 1999 Chris Costello
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
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13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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27 .Dd September 28, 2008
36 .Nm destroy_dev_sched ,
37 .Nm destroy_dev_sched_cb ,
38 .Nm destroy_dev_drain ,
42 and DEVFS registration for devices
47 .Fn make_dev "struct cdevsw *cdevsw" "int unit" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
49 .Fn make_dev_cred "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
51 .Fn make_dev_credf "int flags" "struct cdevsw *cdevsw" "int unit" "struct ucred *cr" "uid_t uid" "gid_t gid" "int perms" "const char *fmt" ...
53 .Fn make_dev_alias "struct cdev *pdev" "const char *fmt" ...
55 .Fn destroy_dev "struct cdev *dev"
57 .Fn destroy_dev_sched "struct cdev *dev"
59 .Fn destroy_dev_sched_cb "struct cdev *dev" "void (*cb)(void *)" "void *arg"
61 .Fn destroy_dev_drain "struct cdevsw *csw"
63 .Fn dev_depends "struct cdev *pdev" "struct cdev *cdev"
69 structure for a new device.
72 of the presence of the new device, that causes corresponding nodes
77 The device will be owned by
79 with the group ownership as
81 The name is the expansion of
83 and following arguments as
86 The name determines its path under
90 mount point and may contain slash
92 characters to denote subdirectories.
93 The permissions of the file specified in
98 .Bd -literal -offset indent -compact
99 #define S_IRWXU 0000700 /* RWX mask for owner */
100 #define S_IRUSR 0000400 /* R for owner */
101 #define S_IWUSR 0000200 /* W for owner */
102 #define S_IXUSR 0000100 /* X for owner */
104 #define S_IRWXG 0000070 /* RWX mask for group */
105 #define S_IRGRP 0000040 /* R for group */
106 #define S_IWGRP 0000020 /* W for group */
107 #define S_IXGRP 0000010 /* X for group */
109 #define S_IRWXO 0000007 /* RWX mask for other */
110 #define S_IROTH 0000004 /* R for other */
111 #define S_IWOTH 0000002 /* W for other */
112 #define S_IXOTH 0000001 /* X for other */
114 #define S_ISUID 0004000 /* set user id on execution */
115 #define S_ISGID 0002000 /* set group id on execution */
116 #define S_ISVTX 0001000 /* sticky bit */
117 #ifndef _POSIX_SOURCE
118 #define S_ISTXT 0001000
124 argument specifies credentials that will be stored in the
126 member of the initialized
130 argument alters the operation of
132 The following values are currently accepted:
134 .Bd -literal -offset indent -compact
135 MAKEDEV_REF reference the created device
140 event handler shall specify
142 flag when creating a device in response to lookup, to avoid race where
143 the device created is destroyed immediately after
145 drops his reference to cdev.
149 function is equivalent to the call
150 .Bd -literal -offset indent
151 make_dev_credf(0, cdevsw, unit, cr, uid, gid, perms, fmt, ...);
156 function call is the same as
157 .Bd -literal -offset indent
158 make_dev_credf(0, cdevsw, unit, NULL, uid, gid, perms, fmt, ...);
163 function takes the returned
167 and makes another (aliased) name for this device.
168 It is an error to call
183 that are available to store state.
184 Both fields are of type
186 These are designed to replace the
190 which can be obtained with
195 function takes the returned
199 and destroys the registration for that device.
200 The notification is sent to
202 about the destruction event.
205 on devices that were created with
210 function establishes a parent-child relationship between two devices.
211 The net effect is that a
213 of the parent device will also result in the destruction of the
216 A device may simultaneously be a parent and a child,
217 so it is possible to build a complete hierarchy.
220 .Fn destroy_dev_sched_cb
221 function schedules execution of the
228 is finished, and if the supplied
230 is not NULL, the callback
232 is called, with argument
235 .Fn destroy_dev_sched
236 function is the same as
237 .Bd -literal -offset indent
238 destroy_dev_sched(cdev, NULL, NULL);
243 driver method cannot call
245 directly. Doing so causes deadlock when
247 waits for all threads to leave the driver methods.
250 sleeps, no non-sleepable locks may be held over the call.
252 .Fn destroy_dev_sched
253 family of functions overcome these issues.
255 The device driver may call the
256 .Fn destroy_dev_drain
257 function to wait until all devices that have supplied
259 as cdevsw, are destroyed. This is useful when driver knows that
260 .Fn destroy_dev_sched
261 is called for all instantiated devices, but need to postpone module
264 is actually finished for all of them.
268 .Xr destroy_dev_drain 9 ,
276 functions first appeared in
288 .Fn destroy_dev_sched ,
289 .Fn destroy_dev_sched_cb